[PATCH V5 00/12] IOMMU probe deferral support

[PATCH V5 00/12] IOMMU probe deferral support

[Sricharan R]

This series calls the dma ops configuration for the devices
at a generic place so that it works for all busses.
The dma_configure_ops for a device is now called during
the device_attach callback just before the probe of the
bus/driver is called. Similarly dma_deconfigure is called during
device/driver_detach path.

pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
       |                         |
pci_bus_add_device     (device_add/driver_register)
       |                         |
device_attach           device_initial_probe
       |                         |
__device_attach_driver    __device_attach_driver
       |
driver_probe_device
       |
really_probe
       |
dma_configure

Similarly on the device/driver_unregister path __device_release_driver is
called which inturn calls dma_deconfigure.

Took the reworked patches [2] from Robin's branch and
rebased on top of Lorenzo's ACPI IORT ARM support series [3].

* Tested with platform and pci devices for probe deferral
  and reprobe on arm64 based platform.
* Tested with arm32 platform.
* Need help for testing with ACPI.

Previous post of this series [6]. 

 [V5]
     * Reworked the pci configuration code hanging outside and
       pushed it to dma_configure as in PATCH#5,6,7.
       Also added a couple of patches that Lorenzo provided for
       correcting the Probe deferring mechanism in case of
       ACPI devices from here [5].

 [V4]
     * Took the reworked patches [2] from Robin's branch and
       rebased on top of Lorenzo's ACPI IORT ARM support series [3].

     * Added the patches for moving the dma ops configuration of
       acpi based devices to probe time as well.
 [V3]
     * Removed the patch to split dma_masks/dma_ops configuration
       separately based on review comments that both masks and ops are
       required only during the device probe time.

     * Reworked the series based on Generic DT bindings series.

     * Added call to iommu's remove_device in the cleanup path for arm and
       arm64.

     * Removed the notifier trick in arm64 to handle early device
       registration.

     * Added reset of dma_ops in cleanup path for arm based on comments.

     * Fixed the pci_iommu_configure path and tested with PCI device as
       well.
 
     * Fixed a bug to return the correct iommu_ops from patch 7 [4] in
       last post.

     * Fixed few other cosmetic comments.
  
 [V2]
     * Updated the Initial post to call dma_configure/deconfigure from
       generic code
 
     * Added iommu add_device callback from of_iommu_configure path

 [V1]
     * Initial post from Laurent Pinchart [1]

[1] http://lists.linuxfoundation.org/pipermail/iommu/2015-May/013016.html
[2] http://www.linux-arm.org/git?p=linux-rm.git;a=shortlog;h=refs/heads/iommu/defer
[3] https://lkml.org/lkml/2016/11/21/141
[4] https://www.mail-archive.com/iommu@lists.linux-foundation.org/msg13940.html
[5] git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git iommu/probe-deferral
[6] https://www.spinics.net/lists/linux-arm-msm/msg24936.html

Laurent Pinchart (3):
  of: dma: Move range size workaround to of_dma_get_range()
  of: dma: Make of_dma_deconfigure() public
  iommu: of: Handle IOMMU lookup failure with deferred probing or error

Lorenzo Pieralisi (2):
  ACPI/IORT: Add function to check SMMUs drivers presence
  ACPI/IORT: Remove linker section for IORT entries probing

Robin Murphy (3):
  iommu/of: Refactor of_iommu_configure() for error handling
  iommu/of: Prepare for deferred IOMMU configuration
  iommu/arm-smmu: Clean up early-probing workarounds

Sricharan R (4):
  drivers: platform: Configure dma operations at probe time
  arm64: dma-mapping: Remove the notifier trick to handle early setting
    of dma_ops
  drivers: acpi: Configure acpi devices dma operation at probe time
  drivers: acpi: Handle IOMMU lookup failure with deferred probing or
    error

 arch/arm64/mm/dma-mapping.c       | 132 ++++----------------------------------
 drivers/acpi/arm64/iort.c         |  40 +++++++++++-
 drivers/acpi/glue.c               |   6 --
 drivers/acpi/scan.c               |   7 +-
 drivers/base/dd.c                 |   9 +++
 drivers/base/dma-mapping.c        |  44 +++++++++++++
 drivers/iommu/arm-smmu-v3.c       |  46 +------------
 drivers/iommu/arm-smmu.c          |  58 +++--------------
 drivers/iommu/of_iommu.c          | 114 +++++++++++++++++++++++---------
 drivers/of/address.c              |  20 +++++-
 drivers/of/device.c               |  36 ++++++-----
 drivers/of/platform.c             |  10 +--
 drivers/pci/probe.c               |  28 --------
 include/acpi/acpi_bus.h           |   2 +-
 include/asm-generic/vmlinux.lds.h |   1 -
 include/linux/acpi.h              |   7 +-
 include/linux/acpi_iort.h         |   3 -
 include/linux/dma-mapping.h       |   3 +
 include/linux/of_device.h         |  10 ++-
 19 files changed, 255 insertions(+), 321 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 00/12] IOMMU probe deferral support

[Sricharan R]

This series calls the dma ops configuration for the devices
at a generic place so that it works for all busses.
The dma_configure_ops for a device is now called during
the device_attach callback just before the probe of the
bus/driver is called. Similarly dma_deconfigure is called during
device/driver_detach path.

pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
       |                         |
pci_bus_add_device     (device_add/driver_register)
       |                         |
device_attach           device_initial_probe
       |                         |
__device_attach_driver    __device_attach_driver
       |
driver_probe_device
       |
really_probe
       |
dma_configure

Similarly on the device/driver_unregister path __device_release_driver is
called which inturn calls dma_deconfigure.

Took the reworked patches [2] from Robin's branch and
rebased on top of Lorenzo's ACPI IORT ARM support series [3].

* Tested with platform and pci devices for probe deferral
  and reprobe on arm64 based platform.
* Tested with arm32 platform.
* Need help for testing with ACPI.

Previous post of this series [6]. 

 [V5]
     * Reworked the pci configuration code hanging outside and
       pushed it to dma_configure as in PATCH#5,6,7.
       Also added a couple of patches that Lorenzo provided for
       correcting the Probe deferring mechanism in case of
       ACPI devices from here [5].

 [V4]
     * Took the reworked patches [2] from Robin's branch and
       rebased on top of Lorenzo's ACPI IORT ARM support series [3].

     * Added the patches for moving the dma ops configuration of
       acpi based devices to probe time as well.
 [V3]
     * Removed the patch to split dma_masks/dma_ops configuration
       separately based on review comments that both masks and ops are
       required only during the device probe time.

     * Reworked the series based on Generic DT bindings series.

     * Added call to iommu's remove_device in the cleanup path for arm and
       arm64.

     * Removed the notifier trick in arm64 to handle early device
       registration.

     * Added reset of dma_ops in cleanup path for arm based on comments.

     * Fixed the pci_iommu_configure path and tested with PCI device as
       well.
 
     * Fixed a bug to return the correct iommu_ops from patch 7 [4] in
       last post.

     * Fixed few other cosmetic comments.
  
 [V2]
     * Updated the Initial post to call dma_configure/deconfigure from
       generic code
 
     * Added iommu add_device callback from of_iommu_configure path

 [V1]
     * Initial post from Laurent Pinchart [1]

[1] http://lists.linuxfoundation.org/pipermail/iommu/2015-May/013016.html
[2] http://www.linux-arm.org/git?p=linux-rm.git;a=shortlog;h=refs/heads/iommu/defer
[3] https://lkml.org/lkml/2016/11/21/141
[4] https://www.mail-archive.com/iommu at lists.linux-foundation.org/msg13940.html
[5] git://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/linux.git iommu/probe-deferral
[6] https://www.spinics.net/lists/linux-arm-msm/msg24936.html

Laurent Pinchart (3):
  of: dma: Move range size workaround to of_dma_get_range()
  of: dma: Make of_dma_deconfigure() public
  iommu: of: Handle IOMMU lookup failure with deferred probing or error

Lorenzo Pieralisi (2):
  ACPI/IORT: Add function to check SMMUs drivers presence
  ACPI/IORT: Remove linker section for IORT entries probing

Robin Murphy (3):
  iommu/of: Refactor of_iommu_configure() for error handling
  iommu/of: Prepare for deferred IOMMU configuration
  iommu/arm-smmu: Clean up early-probing workarounds

Sricharan R (4):
  drivers: platform: Configure dma operations at probe time
  arm64: dma-mapping: Remove the notifier trick to handle early setting
    of dma_ops
  drivers: acpi: Configure acpi devices dma operation at probe time
  drivers: acpi: Handle IOMMU lookup failure with deferred probing or
    error

 arch/arm64/mm/dma-mapping.c       | 132 ++++----------------------------------
 drivers/acpi/arm64/iort.c         |  40 +++++++++++-
 drivers/acpi/glue.c               |   6 --
 drivers/acpi/scan.c               |   7 +-
 drivers/base/dd.c                 |   9 +++
 drivers/base/dma-mapping.c        |  44 +++++++++++++
 drivers/iommu/arm-smmu-v3.c       |  46 +------------
 drivers/iommu/arm-smmu.c          |  58 +++--------------
 drivers/iommu/of_iommu.c          | 114 +++++++++++++++++++++++---------
 drivers/of/address.c              |  20 +++++-
 drivers/of/device.c               |  36 ++++++-----
 drivers/of/platform.c             |  10 +--
 drivers/pci/probe.c               |  28 --------
 include/acpi/acpi_bus.h           |   2 +-
 include/asm-generic/vmlinux.lds.h |   1 -
 include/linux/acpi.h              |   7 +-
 include/linux/acpi_iort.h         |   3 -
 include/linux/dma-mapping.h       |   3 +
 include/linux/of_device.h         |  10 ++-
 19 files changed, 255 insertions(+), 321 deletions(-)

-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 01/12] iommu/of: Refactor of_iommu_configure() for error handling

[Sricharan R]

From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>

In preparation for some upcoming cleverness, rework the control flow in
of_iommu_configure() to minimise duplication and improve the propogation
of errors. It's also as good a time as any to switch over from the
now-just-a-compatibility-wrapper of_iommu_get_ops() to using the generic
IOMMU instance interface directly.

Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 * No change

 drivers/iommu/of_iommu.c | 83 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 53 insertions(+), 30 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 0f57ddc..ee49081 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -96,6 +96,28 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
 }
 EXPORT_SYMBOL_GPL(of_get_dma_window);
 
+static const struct iommu_ops
+*of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec)
+{
+	const struct iommu_ops *ops;
+	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
+	int err;
+
+	ops = iommu_get_instance(fwnode);
+	if (!ops || !ops->of_xlate)
+		return NULL;
+
+	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
+	if (err)
+		return ERR_PTR(err);
+
+	err = ops->of_xlate(dev, iommu_spec);
+	if (err)
+		return ERR_PTR(err);
+
+	return ops;
+}
+
 static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
 {
 	struct of_phandle_args *iommu_spec = data;
@@ -105,10 +127,11 @@ static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
 }
 
 static const struct iommu_ops
-*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np)
+*of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np)
 {
 	const struct iommu_ops *ops;
 	struct of_phandle_args iommu_spec;
+	int err;
 
 	/*
 	 * Start by tracing the RID alias down the PCI topology as
@@ -123,56 +146,56 @@ static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
 	 * bus into the system beyond, and which IOMMU it ends up at.
 	 */
 	iommu_spec.np = NULL;
-	if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
-			   "iommu-map-mask", &iommu_spec.np, iommu_spec.args))
-		return NULL;
+	err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
+			     "iommu-map-mask", &iommu_spec.np,
+			     iommu_spec.args);
+	if (err)
+		return ERR_PTR(err);
 
-	ops = of_iommu_get_ops(iommu_spec.np);
-	if (!ops || !ops->of_xlate ||
-	    iommu_fwspec_init(&pdev->dev, &iommu_spec.np->fwnode, ops) ||
-	    ops->of_xlate(&pdev->dev, &iommu_spec))
-		ops = NULL;
+	ops = of_iommu_xlate(&pdev->dev, &iommu_spec);
 
 	of_node_put(iommu_spec.np);
 	return ops;
 }
 
-const struct iommu_ops *of_iommu_configure(struct device *dev,
-					   struct device_node *master_np)
+static const struct iommu_ops
+*of_platform_iommu_init(struct device *dev, struct device_node *np)
 {
 	struct of_phandle_args iommu_spec;
-	struct device_node *np;
 	const struct iommu_ops *ops = NULL;
 	int idx = 0;
 
-	if (dev_is_pci(dev))
-		return of_pci_iommu_configure(to_pci_dev(dev), master_np);
-
 	/*
 	 * We don't currently walk up the tree looking for a parent IOMMU.
 	 * See the `Notes:' section of
 	 * Documentation/devicetree/bindings/iommu/iommu.txt
 	 */
-	while (!of_parse_phandle_with_args(master_np, "iommus",
-					   "#iommu-cells", idx,
-					   &iommu_spec)) {
-		np = iommu_spec.np;
-		ops = of_iommu_get_ops(np);
-
-		if (!ops || !ops->of_xlate ||
-		    iommu_fwspec_init(dev, &np->fwnode, ops) ||
-		    ops->of_xlate(dev, &iommu_spec))
-			goto err_put_node;
-
-		of_node_put(np);
+	while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells",
+					   idx, &iommu_spec)) {
+		ops = of_iommu_xlate(dev, &iommu_spec);
+		of_node_put(iommu_spec.np);
 		idx++;
+		if (IS_ERR_OR_NULL(ops))
+			break;
 	}
 
 	return ops;
+}
+
+const struct iommu_ops *of_iommu_configure(struct device *dev,
+					   struct device_node *master_np)
+{
+	const struct iommu_ops *ops;
+
+	if (!master_np)
+		return NULL;
+
+	if (dev_is_pci(dev))
+		ops = of_pci_iommu_init(to_pci_dev(dev), master_np);
+	else
+		ops = of_platform_iommu_init(dev, master_np);
 
-err_put_node:
-	of_node_put(np);
-	return NULL;
+	return IS_ERR(ops) ? NULL : ops;
 }
 
 static int __init of_iommu_init(void)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 01/12] iommu/of: Refactor of_iommu_configure() for error handling

[Sricharan R]

From: Robin Murphy <robin.murphy@arm.com>

In preparation for some upcoming cleverness, rework the control flow in
of_iommu_configure() to minimise duplication and improve the propogation
of errors. It's also as good a time as any to switch over from the
now-just-a-compatibility-wrapper of_iommu_get_ops() to using the generic
IOMMU instance interface directly.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 * No change

 drivers/iommu/of_iommu.c | 83 +++++++++++++++++++++++++++++++-----------------
 1 file changed, 53 insertions(+), 30 deletions(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 0f57ddc..ee49081 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -96,6 +96,28 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
 }
 EXPORT_SYMBOL_GPL(of_get_dma_window);
 
+static const struct iommu_ops
+*of_iommu_xlate(struct device *dev, struct of_phandle_args *iommu_spec)
+{
+	const struct iommu_ops *ops;
+	struct fwnode_handle *fwnode = &iommu_spec->np->fwnode;
+	int err;
+
+	ops = iommu_get_instance(fwnode);
+	if (!ops || !ops->of_xlate)
+		return NULL;
+
+	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
+	if (err)
+		return ERR_PTR(err);
+
+	err = ops->of_xlate(dev, iommu_spec);
+	if (err)
+		return ERR_PTR(err);
+
+	return ops;
+}
+
 static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
 {
 	struct of_phandle_args *iommu_spec = data;
@@ -105,10 +127,11 @@ static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
 }
 
 static const struct iommu_ops
-*of_pci_iommu_configure(struct pci_dev *pdev, struct device_node *bridge_np)
+*of_pci_iommu_init(struct pci_dev *pdev, struct device_node *bridge_np)
 {
 	const struct iommu_ops *ops;
 	struct of_phandle_args iommu_spec;
+	int err;
 
 	/*
 	 * Start by tracing the RID alias down the PCI topology as
@@ -123,56 +146,56 @@ static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
 	 * bus into the system beyond, and which IOMMU it ends up at.
 	 */
 	iommu_spec.np = NULL;
-	if (of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
-			   "iommu-map-mask", &iommu_spec.np, iommu_spec.args))
-		return NULL;
+	err = of_pci_map_rid(bridge_np, iommu_spec.args[0], "iommu-map",
+			     "iommu-map-mask", &iommu_spec.np,
+			     iommu_spec.args);
+	if (err)
+		return ERR_PTR(err);
 
-	ops = of_iommu_get_ops(iommu_spec.np);
-	if (!ops || !ops->of_xlate ||
-	    iommu_fwspec_init(&pdev->dev, &iommu_spec.np->fwnode, ops) ||
-	    ops->of_xlate(&pdev->dev, &iommu_spec))
-		ops = NULL;
+	ops = of_iommu_xlate(&pdev->dev, &iommu_spec);
 
 	of_node_put(iommu_spec.np);
 	return ops;
 }
 
-const struct iommu_ops *of_iommu_configure(struct device *dev,
-					   struct device_node *master_np)
+static const struct iommu_ops
+*of_platform_iommu_init(struct device *dev, struct device_node *np)
 {
 	struct of_phandle_args iommu_spec;
-	struct device_node *np;
 	const struct iommu_ops *ops = NULL;
 	int idx = 0;
 
-	if (dev_is_pci(dev))
-		return of_pci_iommu_configure(to_pci_dev(dev), master_np);
-
 	/*
 	 * We don't currently walk up the tree looking for a parent IOMMU.
 	 * See the `Notes:' section of
 	 * Documentation/devicetree/bindings/iommu/iommu.txt
 	 */
-	while (!of_parse_phandle_with_args(master_np, "iommus",
-					   "#iommu-cells", idx,
-					   &iommu_spec)) {
-		np = iommu_spec.np;
-		ops = of_iommu_get_ops(np);
-
-		if (!ops || !ops->of_xlate ||
-		    iommu_fwspec_init(dev, &np->fwnode, ops) ||
-		    ops->of_xlate(dev, &iommu_spec))
-			goto err_put_node;
-
-		of_node_put(np);
+	while (!of_parse_phandle_with_args(np, "iommus", "#iommu-cells",
+					   idx, &iommu_spec)) {
+		ops = of_iommu_xlate(dev, &iommu_spec);
+		of_node_put(iommu_spec.np);
 		idx++;
+		if (IS_ERR_OR_NULL(ops))
+			break;
 	}
 
 	return ops;
+}
+
+const struct iommu_ops *of_iommu_configure(struct device *dev,
+					   struct device_node *master_np)
+{
+	const struct iommu_ops *ops;
+
+	if (!master_np)
+		return NULL;
+
+	if (dev_is_pci(dev))
+		ops = of_pci_iommu_init(to_pci_dev(dev), master_np);
+	else
+		ops = of_platform_iommu_init(dev, master_np);
 
-err_put_node:
-	of_node_put(np);
-	return NULL;
+	return IS_ERR(ops) ? NULL : ops;
 }
 
 static int __init of_iommu_init(void)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 02/12] iommu/of: Prepare for deferred IOMMU configuration

[Sricharan R]

From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>

IOMMU configuration represents unchanging properties of the hardware,
and as such should only need happen once in a device's lifetime, but
the necessary interaction with the IOMMU device and driver complicates
exactly when that point should be.

Since the only reasonable tool available for handling the inter-device
dependency is probe deferral, we need to prepare of_iommu_configure()
to run later than it is currently called (i.e. at driver probe rather
than device creation), to handle being retried, and to tell whether a
not-yet present IOMMU should be waited for or skipped (by virtue of
having declared a built-in driver or not).

Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 * No change

 drivers/iommu/of_iommu.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index ee49081..349bd1d 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -104,12 +104,20 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
 	int err;
 
 	ops = iommu_get_instance(fwnode);
-	if (!ops || !ops->of_xlate)
+	if ((ops && !ops->of_xlate) ||
+	    (!ops && !of_match_node(&__iommu_of_table, iommu_spec->np)))
 		return NULL;
 
 	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
 	if (err)
 		return ERR_PTR(err);
+	/*
+	 * The otherwise-empty fwspec handily serves to indicate the specific
+	 * IOMMU device we're waiting for, which will be useful if we ever get
+	 * a proper probe-ordering dependency mechanism in future.
+	 */
+	if (!ops)
+		return ERR_PTR(-EPROBE_DEFER);
 
 	err = ops->of_xlate(dev, iommu_spec);
 	if (err)
@@ -186,14 +194,34 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 					   struct device_node *master_np)
 {
 	const struct iommu_ops *ops;
+	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 
 	if (!master_np)
 		return NULL;
 
+	if (fwspec) {
+		if (fwspec->ops)
+			return fwspec->ops;
+
+		/* In the deferred case, start again from scratch */
+		iommu_fwspec_free(dev);
+	}
+
 	if (dev_is_pci(dev))
 		ops = of_pci_iommu_init(to_pci_dev(dev), master_np);
 	else
 		ops = of_platform_iommu_init(dev, master_np);
+	/*
+	 * If we have reason to believe the IOMMU driver missed the initial
+	 * add_device callback for dev, replay it to get things in order.
+	 */
+	if (!IS_ERR_OR_NULL(ops) && ops->add_device &&
+	    dev->bus && !dev->iommu_group) {
+		int err = ops->add_device(dev);
+
+		if (err)
+			ops = ERR_PTR(err);
+	}
 
 	return IS_ERR(ops) ? NULL : ops;
 }
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 02/12] iommu/of: Prepare for deferred IOMMU configuration

[Sricharan R]

From: Robin Murphy <robin.murphy@arm.com>

IOMMU configuration represents unchanging properties of the hardware,
and as such should only need happen once in a device's lifetime, but
the necessary interaction with the IOMMU device and driver complicates
exactly when that point should be.

Since the only reasonable tool available for handling the inter-device
dependency is probe deferral, we need to prepare of_iommu_configure()
to run later than it is currently called (i.e. at driver probe rather
than device creation), to handle being retried, and to tell whether a
not-yet present IOMMU should be waited for or skipped (by virtue of
having declared a built-in driver or not).

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 * No change

 drivers/iommu/of_iommu.c | 30 +++++++++++++++++++++++++++++-
 1 file changed, 29 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index ee49081..349bd1d 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -104,12 +104,20 @@ int of_get_dma_window(struct device_node *dn, const char *prefix, int index,
 	int err;
 
 	ops = iommu_get_instance(fwnode);
-	if (!ops || !ops->of_xlate)
+	if ((ops && !ops->of_xlate) ||
+	    (!ops && !of_match_node(&__iommu_of_table, iommu_spec->np)))
 		return NULL;
 
 	err = iommu_fwspec_init(dev, &iommu_spec->np->fwnode, ops);
 	if (err)
 		return ERR_PTR(err);
+	/*
+	 * The otherwise-empty fwspec handily serves to indicate the specific
+	 * IOMMU device we're waiting for, which will be useful if we ever get
+	 * a proper probe-ordering dependency mechanism in future.
+	 */
+	if (!ops)
+		return ERR_PTR(-EPROBE_DEFER);
 
 	err = ops->of_xlate(dev, iommu_spec);
 	if (err)
@@ -186,14 +194,34 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 					   struct device_node *master_np)
 {
 	const struct iommu_ops *ops;
+	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 
 	if (!master_np)
 		return NULL;
 
+	if (fwspec) {
+		if (fwspec->ops)
+			return fwspec->ops;
+
+		/* In the deferred case, start again from scratch */
+		iommu_fwspec_free(dev);
+	}
+
 	if (dev_is_pci(dev))
 		ops = of_pci_iommu_init(to_pci_dev(dev), master_np);
 	else
 		ops = of_platform_iommu_init(dev, master_np);
+	/*
+	 * If we have reason to believe the IOMMU driver missed the initial
+	 * add_device callback for dev, replay it to get things in order.
+	 */
+	if (!IS_ERR_OR_NULL(ops) && ops->add_device &&
+	    dev->bus && !dev->iommu_group) {
+		int err = ops->add_device(dev);
+
+		if (err)
+			ops = ERR_PTR(err);
+	}
 
 	return IS_ERR(ops) ? NULL : ops;
 }
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 03/12] of: dma: Move range size workaround to of_dma_get_range()

[Sricharan R]

From: Laurent Pinchart <laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>

Invalid dma-ranges values should be worked around when retrieving the
DMA range in of_dma_get_range(), not by all callers of the function.
This isn't much of a problem now that we have a single caller, but that
situation will change when moving DMA configuration to device probe
time.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
---
 *No change

 drivers/of/address.c | 20 ++++++++++++++++++--
 drivers/of/device.c  | 15 ---------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 02b2903..6aeb816 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -819,8 +819,8 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index,
  *	CPU addr (phys_addr_t)	: pna cells
  *	size			: nsize cells
  *
- * It returns -ENODEV if "dma-ranges" property was not found
- * for this device in DT.
+ * Return 0 on success, -ENODEV if the "dma-ranges" property was not found for
+ * this device in DT, or -EINVAL if the CPU address or size is invalid.
  */
 int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
 {
@@ -880,6 +880,22 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
 	*dma_addr = dmaaddr;
 
 	*size = of_read_number(ranges + naddr + pna, nsize);
+	/*
+	 * DT nodes sometimes incorrectly set the size as a mask. Work around
+	 * those incorrect DT by computing the size as mask + 1.
+	 */
+	if (*size & 1) {
+		pr_warn("%s: size 0x%llx for dma-range in node(%s) set as mask\n",
+			__func__, *size, np->full_name);
+		*size = *size + 1;
+	}
+
+	if (!*size) {
+		pr_err("%s: invalid size zero for dma-range in node(%s)\n",
+		       __func__, np->full_name);
+		ret = -EINVAL;
+		goto out;
+	}
 
 	pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
 		 *dma_addr, *paddr, *size);
diff --git a/drivers/of/device.c b/drivers/of/device.c
index fd5cfad..d9898d9 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -110,21 +110,6 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 		size = dev->coherent_dma_mask + 1;
 	} else {
 		offset = PFN_DOWN(paddr - dma_addr);
-
-		/*
-		 * Add a work around to treat the size as mask + 1 in case
-		 * it is defined in DT as a mask.
-		 */
-		if (size & 1) {
-			dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
-				 size);
-			size = size + 1;
-		}
-
-		if (!size) {
-			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
-			return;
-		}
 		dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 	}
 
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 03/12] of: dma: Move range size workaround to of_dma_get_range()

[Sricharan R]

From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Invalid dma-ranges values should be worked around when retrieving the
DMA range in of_dma_get_range(), not by all callers of the function.
This isn't much of a problem now that we have a single caller, but that
situation will change when moving DMA configuration to device probe
time.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 *No change

 drivers/of/address.c | 20 ++++++++++++++++++--
 drivers/of/device.c  | 15 ---------------
 2 files changed, 18 insertions(+), 17 deletions(-)

diff --git a/drivers/of/address.c b/drivers/of/address.c
index 02b2903..6aeb816 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -819,8 +819,8 @@ void __iomem *of_io_request_and_map(struct device_node *np, int index,
  *	CPU addr (phys_addr_t)	: pna cells
  *	size			: nsize cells
  *
- * It returns -ENODEV if "dma-ranges" property was not found
- * for this device in DT.
+ * Return 0 on success, -ENODEV if the "dma-ranges" property was not found for
+ * this device in DT, or -EINVAL if the CPU address or size is invalid.
  */
 int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *size)
 {
@@ -880,6 +880,22 @@ int of_dma_get_range(struct device_node *np, u64 *dma_addr, u64 *paddr, u64 *siz
 	*dma_addr = dmaaddr;
 
 	*size = of_read_number(ranges + naddr + pna, nsize);
+	/*
+	 * DT nodes sometimes incorrectly set the size as a mask. Work around
+	 * those incorrect DT by computing the size as mask + 1.
+	 */
+	if (*size & 1) {
+		pr_warn("%s: size 0x%llx for dma-range in node(%s) set as mask\n",
+			__func__, *size, np->full_name);
+		*size = *size + 1;
+	}
+
+	if (!*size) {
+		pr_err("%s: invalid size zero for dma-range in node(%s)\n",
+		       __func__, np->full_name);
+		ret = -EINVAL;
+		goto out;
+	}
 
 	pr_debug("dma_addr(%llx) cpu_addr(%llx) size(%llx)\n",
 		 *dma_addr, *paddr, *size);
diff --git a/drivers/of/device.c b/drivers/of/device.c
index fd5cfad..d9898d9 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -110,21 +110,6 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 		size = dev->coherent_dma_mask + 1;
 	} else {
 		offset = PFN_DOWN(paddr - dma_addr);
-
-		/*
-		 * Add a work around to treat the size as mask + 1 in case
-		 * it is defined in DT as a mask.
-		 */
-		if (size & 1) {
-			dev_warn(dev, "Invalid size 0x%llx for dma-range\n",
-				 size);
-			size = size + 1;
-		}
-
-		if (!size) {
-			dev_err(dev, "Adjusted size 0x%llx invalid\n", size);
-			return;
-		}
 		dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
 	}
 
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 04/12] of: dma: Make of_dma_deconfigure() public

[Sricharan R]

From: Laurent Pinchart <laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>

As part of moving DMA initializing to probe time the
of_dma_deconfigure() function will need to be called from different
source files. Make it public and move it to drivers/of/device.c where
the of_dma_configure() function is.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
---
 * No change

 drivers/of/device.c       | 12 ++++++++++++
 drivers/of/platform.c     |  5 -----
 include/linux/of_device.h |  3 +++
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index d9898d9..1c843e2 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -136,6 +136,18 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 }
 EXPORT_SYMBOL_GPL(of_dma_configure);
 
+/**
+ * of_dma_deconfigure - Clean up DMA configuration
+ * @dev:	Device for which to clean up DMA configuration
+ *
+ * Clean up all configuration performed by of_dma_configure_ops() and free all
+ * resources that have been allocated.
+ */
+void of_dma_deconfigure(struct device *dev)
+{
+	arch_teardown_dma_ops(dev);
+}
+
 int of_device_register(struct platform_device *pdev)
 {
 	device_initialize(&pdev->dev);
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index b8064bc..57418f7 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -158,11 +158,6 @@ struct platform_device *of_device_alloc(struct device_node *np,
 }
 EXPORT_SYMBOL(of_device_alloc);
 
-static void of_dma_deconfigure(struct device *dev)
-{
-	arch_teardown_dma_ops(dev);
-}
-
 /**
  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
  * @np: pointer to node to create device for
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index cc7dd687..d20a31a 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -56,6 +56,7 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 }
 
 void of_dma_configure(struct device *dev, struct device_node *np);
+void of_dma_deconfigure(struct device *dev);
 #else /* CONFIG_OF */
 
 static inline int of_driver_match_device(struct device *dev,
@@ -100,6 +101,8 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 }
 static inline void of_dma_configure(struct device *dev, struct device_node *np)
 {}
+static inline void of_dma_deconfigure(struct device *dev)
+{}
 #endif /* CONFIG_OF */
 
 #endif /* _LINUX_OF_DEVICE_H */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 04/12] of: dma: Make of_dma_deconfigure() public

[Sricharan R]

From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

As part of moving DMA initializing to probe time the
of_dma_deconfigure() function will need to be called from different
source files. Make it public and move it to drivers/of/device.c where
the of_dma_configure() function is.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
---
 * No change

 drivers/of/device.c       | 12 ++++++++++++
 drivers/of/platform.c     |  5 -----
 include/linux/of_device.h |  3 +++
 3 files changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/of/device.c b/drivers/of/device.c
index d9898d9..1c843e2 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -136,6 +136,18 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 }
 EXPORT_SYMBOL_GPL(of_dma_configure);
 
+/**
+ * of_dma_deconfigure - Clean up DMA configuration
+ * @dev:	Device for which to clean up DMA configuration
+ *
+ * Clean up all configuration performed by of_dma_configure_ops() and free all
+ * resources that have been allocated.
+ */
+void of_dma_deconfigure(struct device *dev)
+{
+	arch_teardown_dma_ops(dev);
+}
+
 int of_device_register(struct platform_device *pdev)
 {
 	device_initialize(&pdev->dev);
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index b8064bc..57418f7 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -158,11 +158,6 @@ struct platform_device *of_device_alloc(struct device_node *np,
 }
 EXPORT_SYMBOL(of_device_alloc);
 
-static void of_dma_deconfigure(struct device *dev)
-{
-	arch_teardown_dma_ops(dev);
-}
-
 /**
  * of_platform_device_create_pdata - Alloc, initialize and register an of_device
  * @np: pointer to node to create device for
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index cc7dd687..d20a31a 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -56,6 +56,7 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 }
 
 void of_dma_configure(struct device *dev, struct device_node *np);
+void of_dma_deconfigure(struct device *dev);
 #else /* CONFIG_OF */
 
 static inline int of_driver_match_device(struct device *dev,
@@ -100,6 +101,8 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 }
 static inline void of_dma_configure(struct device *dev, struct device_node *np)
 {}
+static inline void of_dma_deconfigure(struct device *dev)
+{}
 #endif /* CONFIG_OF */
 
 #endif /* _LINUX_OF_DEVICE_H */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan R]

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet. The dma_configure for the device is
now called from the generic device_attach callback just before the
bus/driver probe is called. This way, configuring the DMA ops for the
device would be called at the same place for all bus_types, hence the
deferred probing mechanism should work for all buses as well.

pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
       |                         |
pci_bus_add_device     (device_add/driver_register)
       |                         |
device_attach           device_initial_probe
       |                         |
__device_attach_driver    __device_attach_driver
       |
driver_probe_device
       |
really_probe
       |
dma_configure

Similarly on the device/driver_unregister path __device_release_driver is
called which inturn calls dma_deconfigure.

Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 * Removed the dma configuration for the pci devices in case of DT
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/base/dd.c           |  9 +++++++++
 drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
 drivers/of/platform.c       |  5 +----
 drivers/pci/probe.c         |  5 +----
 include/linux/dma-mapping.h |  3 +++
 5 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index a1fbf55..4882f06 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -19,6 +19,7 @@
 
 #include <linux/device.h>
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/kthread.h>
 #include <linux/wait.h>
@@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	if (ret)
 		goto pinctrl_bind_failed;
 
+	ret = dma_configure(dev);
+	if (ret)
+		goto dma_failed;
+
 	if (driver_sysfs_add(dev)) {
 		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
 			__func__, dev_name(dev));
@@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	goto done;
 
 probe_failed:
+	dma_deconfigure(dev);
+dma_failed:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
@@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 			drv->remove(dev);
 
 		device_links_driver_cleanup(dev);
+		dma_deconfigure(dev);
+
 		devres_release_all(dev);
 		dev->driver = NULL;
 		dev_set_drvdata(dev, NULL);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index efd71cf..dfe6fd7 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
@@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
 	vunmap(cpu_addr);
 }
 #endif
+
+/*
+ * Common configuration to enable DMA API use for a device
+ */
+#include <linux/pci.h>
+
+int dma_configure(struct device *dev)
+{
+	struct device *_dev = dev;
+	int is_pci = dev_is_pci(dev);
+
+	if (is_pci) {
+		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
+		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
+		    _dev->parent->of_node)
+			_dev = _dev->parent;
+	}
+
+	if (_dev->of_node)
+		of_dma_configure(dev, _dev->of_node);
+
+	if (is_pci)
+		pci_put_host_bridge_device(_dev);
+
+	return 0;
+}
+
+void dma_deconfigure(struct device *dev)
+{
+	of_dma_deconfigure(dev);
+}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 57418f7..cf35030 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/of_iommu.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
@@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
 
 	dev->dev.bus = &platform_bus_type;
 	dev->dev.platform_data = platform_data;
-	of_dma_configure(&dev->dev, dev->dev.of_node);
 	of_msi_configure(&dev->dev, dev->dev.of_node);
 
 	if (of_device_add(dev) != 0) {
-		of_dma_deconfigure(&dev->dev);
 		platform_device_put(dev);
 		goto err_clear_flag;
 	}
@@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
 		dev_set_name(&dev->dev, "%s", bus_id);
 	else
 		of_device_make_bus_id(&dev->dev);
-	of_dma_configure(&dev->dev, dev->dev.of_node);
 
 	/* Allow the HW Peripheral ID to be overridden */
 	prop = of_get_property(node, "arm,primecell-periphid", NULL);
@@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
 		amba_device_unregister(to_amba_device(dev));
 #endif
 
-	of_dma_deconfigure(dev);
 	of_node_clear_flag(dev->of_node, OF_POPULATED);
 	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
 	return 0;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index e164b5c..634d34e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
 {
 	struct device *bridge = pci_get_host_bridge_device(dev);
 
-	if (IS_ENABLED(CONFIG_OF) &&
-		bridge->parent && bridge->parent->of_node) {
-			of_dma_configure(&dev->dev, bridge->parent->of_node);
-	} else if (has_acpi_companion(bridge)) {
+	if (has_acpi_companion(bridge)) {
 		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
 		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
 
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index abf685ed..b56320a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
 }
 #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
 
+int dma_configure(struct device *dev);
+void dma_deconfigure(struct device *dev);
+
 /*
  * Managed DMA API
  */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan R]

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet. The dma_configure for the device is
now called from the generic device_attach callback just before the
bus/driver probe is called. This way, configuring the DMA ops for the
device would be called at the same place for all bus_types, hence the
deferred probing mechanism should work for all buses as well.

pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
       |                         |
pci_bus_add_device     (device_add/driver_register)
       |                         |
device_attach           device_initial_probe
       |                         |
__device_attach_driver    __device_attach_driver
       |
driver_probe_device
       |
really_probe
       |
dma_configure

Similarly on the device/driver_unregister path __device_release_driver is
called which inturn calls dma_deconfigure.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 * Removed the dma configuration for the pci devices in case of DT
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/base/dd.c           |  9 +++++++++
 drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
 drivers/of/platform.c       |  5 +----
 drivers/pci/probe.c         |  5 +----
 include/linux/dma-mapping.h |  3 +++
 5 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index a1fbf55..4882f06 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -19,6 +19,7 @@
 
 #include <linux/device.h>
 #include <linux/delay.h>
+#include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/kthread.h>
 #include <linux/wait.h>
@@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	if (ret)
 		goto pinctrl_bind_failed;
 
+	ret = dma_configure(dev);
+	if (ret)
+		goto dma_failed;
+
 	if (driver_sysfs_add(dev)) {
 		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
 			__func__, dev_name(dev));
@@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	goto done;
 
 probe_failed:
+	dma_deconfigure(dev);
+dma_failed:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
 					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
@@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 			drv->remove(dev);
 
 		device_links_driver_cleanup(dev);
+		dma_deconfigure(dev);
+
 		devres_release_all(dev);
 		dev->driver = NULL;
 		dev_set_drvdata(dev, NULL);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index efd71cf..dfe6fd7 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,7 @@
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
+#include <linux/of_device.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 
@@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
 	vunmap(cpu_addr);
 }
 #endif
+
+/*
+ * Common configuration to enable DMA API use for a device
+ */
+#include <linux/pci.h>
+
+int dma_configure(struct device *dev)
+{
+	struct device *_dev = dev;
+	int is_pci = dev_is_pci(dev);
+
+	if (is_pci) {
+		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
+		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
+		    _dev->parent->of_node)
+			_dev = _dev->parent;
+	}
+
+	if (_dev->of_node)
+		of_dma_configure(dev, _dev->of_node);
+
+	if (is_pci)
+		pci_put_host_bridge_device(_dev);
+
+	return 0;
+}
+
+void dma_deconfigure(struct device *dev)
+{
+	of_dma_deconfigure(dev);
+}
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 57418f7..cf35030 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/of_address.h>
 #include <linux/of_device.h>
+#include <linux/of_iommu.h>
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
@@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
 
 	dev->dev.bus = &platform_bus_type;
 	dev->dev.platform_data = platform_data;
-	of_dma_configure(&dev->dev, dev->dev.of_node);
 	of_msi_configure(&dev->dev, dev->dev.of_node);
 
 	if (of_device_add(dev) != 0) {
-		of_dma_deconfigure(&dev->dev);
 		platform_device_put(dev);
 		goto err_clear_flag;
 	}
@@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
 		dev_set_name(&dev->dev, "%s", bus_id);
 	else
 		of_device_make_bus_id(&dev->dev);
-	of_dma_configure(&dev->dev, dev->dev.of_node);
 
 	/* Allow the HW Peripheral ID to be overridden */
 	prop = of_get_property(node, "arm,primecell-periphid", NULL);
@@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
 		amba_device_unregister(to_amba_device(dev));
 #endif
 
-	of_dma_deconfigure(dev);
 	of_node_clear_flag(dev->of_node, OF_POPULATED);
 	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
 	return 0;
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index e164b5c..634d34e 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
 {
 	struct device *bridge = pci_get_host_bridge_device(dev);
 
-	if (IS_ENABLED(CONFIG_OF) &&
-		bridge->parent && bridge->parent->of_node) {
-			of_dma_configure(&dev->dev, bridge->parent->of_node);
-	} else if (has_acpi_companion(bridge)) {
+	if (has_acpi_companion(bridge)) {
 		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
 		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
 
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index abf685ed..b56320a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
 }
 #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
 
+int dma_configure(struct device *dev);
+void dma_deconfigure(struct device *dev);
+
 /*
  * Managed DMA API
  */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 06/12] iommu: of: Handle IOMMU lookup failure with deferred probing or error

[Sricharan R]

From: Laurent Pinchart <laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>

Failures to look up an IOMMU when parsing the DT iommus property need to
be handled separately from the .of_xlate() failures to support deferred
probing.

The lack of a registered IOMMU can be caused by the lack of a driver for
the IOMMU, the IOMMU device probe not having been performed yet, having
been deferred, or having failed.

The first case occurs when the device tree describes the bus master and
IOMMU topology correctly but no device driver exists for the IOMMU yet
or the device driver has not been compiled in. Return NULL, the caller
will configure the device without an IOMMU.

The second and third cases are handled by deferring the probe of the bus
master device which will eventually get reprobed after the IOMMU.

The last case is currently handled by deferring the probe of the bus
master device as well. A mechanism to either configure the bus master
device without an IOMMU or to fail the bus master device probe depending
on whether the IOMMU is optional or mandatory would be a good
enhancement.

Signed-off-by: Laurent Pichart <laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org>
Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 * Removed the dma configuration for the pci devices in case of DT
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/base/dma-mapping.c | 5 +++--
 drivers/iommu/of_iommu.c   | 5 +++--
 drivers/of/device.c        | 9 +++++++--
 include/linux/of_device.h  | 9 ++++++---
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index dfe6fd7..f82212c 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -352,6 +352,7 @@ int dma_configure(struct device *dev)
 {
 	struct device *_dev = dev;
 	int is_pci = dev_is_pci(dev);
+	int ret = 0;
 
 	if (is_pci) {
 		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
@@ -361,12 +362,12 @@ int dma_configure(struct device *dev)
 	}
 
 	if (_dev->of_node)
-		of_dma_configure(dev, _dev->of_node);
+		ret = of_dma_configure(dev, _dev->of_node);
 
 	if (is_pci)
 		pci_put_host_bridge_device(_dev);
 
-	return 0;
+	return ret;
 }
 
 void dma_deconfigure(struct device *dev)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 349bd1d..9529d6c 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -23,6 +23,7 @@
 #include <linux/of.h>
 #include <linux/of_iommu.h>
 #include <linux/of_pci.h>
+#include <linux/pci.h>
 #include <linux/slab.h>
 
 static const struct of_device_id __iommu_of_table_sentinel
@@ -223,7 +224,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 			ops = ERR_PTR(err);
 	}
 
-	return IS_ERR(ops) ? NULL : ops;
+	return ops;
 }
 
 static int __init of_iommu_init(void)
@@ -234,7 +235,7 @@ static int __init of_iommu_init(void)
 	for_each_matching_node_and_match(np, matches, &match) {
 		const of_iommu_init_fn init_fn = match->data;
 
-		if (init_fn(np))
+		if (init_fn && init_fn(np))
 			pr_err("Failed to initialise IOMMU %s\n",
 				of_node_full_name(np));
 	}
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 1c843e2..d58595c 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -82,7 +82,7 @@ int of_device_add(struct platform_device *ofdev)
  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  * to fix up DMA configuration.
  */
-void of_dma_configure(struct device *dev, struct device_node *np)
+int of_dma_configure(struct device *dev, struct device_node *np)
 {
 	u64 dma_addr, paddr, size;
 	int ret;
@@ -107,7 +107,7 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 	ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
 	if (ret < 0) {
 		dma_addr = offset = 0;
-		size = dev->coherent_dma_mask + 1;
+		size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 	} else {
 		offset = PFN_DOWN(paddr - dma_addr);
 		dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
@@ -129,10 +129,15 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 		coherent ? " " : " not ");
 
 	iommu = of_iommu_configure(dev, np);
+	if (IS_ERR(iommu))
+		return PTR_ERR(iommu);
+
 	dev_dbg(dev, "device is%sbehind an iommu\n",
 		iommu ? " " : " not ");
 
 	arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(of_dma_configure);
 
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index d20a31a..6dca65c 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -55,7 +55,7 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 	return of_node_get(cpu_dev->of_node);
 }
 
-void of_dma_configure(struct device *dev, struct device_node *np);
+int of_dma_configure(struct device *dev, struct device_node *np);
 void of_dma_deconfigure(struct device *dev);
 #else /* CONFIG_OF */
 
@@ -99,8 +99,11 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 {
 	return NULL;
 }
-static inline void of_dma_configure(struct device *dev, struct device_node *np)
-{}
+
+static inline int of_dma_configure(struct device *dev, struct device_node *np)
+{
+	return 0;
+}
 static inline void of_dma_deconfigure(struct device *dev)
 {}
 #endif /* CONFIG_OF */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 06/12] iommu: of: Handle IOMMU lookup failure with deferred probing or error

[Sricharan R]

From: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

Failures to look up an IOMMU when parsing the DT iommus property need to
be handled separately from the .of_xlate() failures to support deferred
probing.

The lack of a registered IOMMU can be caused by the lack of a driver for
the IOMMU, the IOMMU device probe not having been performed yet, having
been deferred, or having failed.

The first case occurs when the device tree describes the bus master and
IOMMU topology correctly but no device driver exists for the IOMMU yet
or the device driver has not been compiled in. Return NULL, the caller
will configure the device without an IOMMU.

The second and third cases are handled by deferring the probe of the bus
master device which will eventually get reprobed after the IOMMU.

The last case is currently handled by deferring the probe of the bus
master device as well. A mechanism to either configure the bus master
device without an IOMMU or to fail the bus master device probe depending
on whether the IOMMU is optional or mandatory would be a good
enhancement.

Signed-off-by: Laurent Pichart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 * Removed the dma configuration for the pci devices in case of DT
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/base/dma-mapping.c | 5 +++--
 drivers/iommu/of_iommu.c   | 5 +++--
 drivers/of/device.c        | 9 +++++++--
 include/linux/of_device.h  | 9 ++++++---
 4 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index dfe6fd7..f82212c 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -352,6 +352,7 @@ int dma_configure(struct device *dev)
 {
 	struct device *_dev = dev;
 	int is_pci = dev_is_pci(dev);
+	int ret = 0;
 
 	if (is_pci) {
 		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
@@ -361,12 +362,12 @@ int dma_configure(struct device *dev)
 	}
 
 	if (_dev->of_node)
-		of_dma_configure(dev, _dev->of_node);
+		ret = of_dma_configure(dev, _dev->of_node);
 
 	if (is_pci)
 		pci_put_host_bridge_device(_dev);
 
-	return 0;
+	return ret;
 }
 
 void dma_deconfigure(struct device *dev)
diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 349bd1d..9529d6c 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -23,6 +23,7 @@
 #include <linux/of.h>
 #include <linux/of_iommu.h>
 #include <linux/of_pci.h>
+#include <linux/pci.h>
 #include <linux/slab.h>
 
 static const struct of_device_id __iommu_of_table_sentinel
@@ -223,7 +224,7 @@ const struct iommu_ops *of_iommu_configure(struct device *dev,
 			ops = ERR_PTR(err);
 	}
 
-	return IS_ERR(ops) ? NULL : ops;
+	return ops;
 }
 
 static int __init of_iommu_init(void)
@@ -234,7 +235,7 @@ static int __init of_iommu_init(void)
 	for_each_matching_node_and_match(np, matches, &match) {
 		const of_iommu_init_fn init_fn = match->data;
 
-		if (init_fn(np))
+		if (init_fn && init_fn(np))
 			pr_err("Failed to initialise IOMMU %s\n",
 				of_node_full_name(np));
 	}
diff --git a/drivers/of/device.c b/drivers/of/device.c
index 1c843e2..d58595c 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -82,7 +82,7 @@ int of_device_add(struct platform_device *ofdev)
  * can use a platform bus notifier and handle BUS_NOTIFY_ADD_DEVICE events
  * to fix up DMA configuration.
  */
-void of_dma_configure(struct device *dev, struct device_node *np)
+int of_dma_configure(struct device *dev, struct device_node *np)
 {
 	u64 dma_addr, paddr, size;
 	int ret;
@@ -107,7 +107,7 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 	ret = of_dma_get_range(np, &dma_addr, &paddr, &size);
 	if (ret < 0) {
 		dma_addr = offset = 0;
-		size = dev->coherent_dma_mask + 1;
+		size = max(dev->coherent_dma_mask, dev->coherent_dma_mask + 1);
 	} else {
 		offset = PFN_DOWN(paddr - dma_addr);
 		dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", offset);
@@ -129,10 +129,15 @@ void of_dma_configure(struct device *dev, struct device_node *np)
 		coherent ? " " : " not ");
 
 	iommu = of_iommu_configure(dev, np);
+	if (IS_ERR(iommu))
+		return PTR_ERR(iommu);
+
 	dev_dbg(dev, "device is%sbehind an iommu\n",
 		iommu ? " " : " not ");
 
 	arch_setup_dma_ops(dev, dma_addr, size, iommu, coherent);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(of_dma_configure);
 
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index d20a31a..6dca65c 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -55,7 +55,7 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 	return of_node_get(cpu_dev->of_node);
 }
 
-void of_dma_configure(struct device *dev, struct device_node *np);
+int of_dma_configure(struct device *dev, struct device_node *np);
 void of_dma_deconfigure(struct device *dev);
 #else /* CONFIG_OF */
 
@@ -99,8 +99,11 @@ static inline struct device_node *of_cpu_device_node_get(int cpu)
 {
 	return NULL;
 }
-static inline void of_dma_configure(struct device *dev, struct device_node *np)
-{}
+
+static inline int of_dma_configure(struct device *dev, struct device_node *np)
+{
+	return 0;
+}
 static inline void of_dma_deconfigure(struct device *dev)
 {}
 #endif /* CONFIG_OF */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 07/12] arm64: dma-mapping: Remove the notifier trick to handle early setting of dma_ops

[Sricharan R]

With arch_setup_dma_ops now being called late during device's probe after
the device's iommu is probed, the notifier trick required to handle the
early setup of dma_ops before the iommu group gets created is not
required. So removing the notifier's here.

Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
[rm: clean up even more]
Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
---
 * No change

 arch/arm64/mm/dma-mapping.c | 132 ++++----------------------------------------
 1 file changed, 12 insertions(+), 120 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index ae9f817..beee5ce 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -803,140 +803,32 @@ static void __iommu_unmap_sg_attrs(struct device *dev,
 	.mapping_error = iommu_dma_mapping_error,
 };
 
-/*
- * TODO: Right now __iommu_setup_dma_ops() gets called too early to do
- * everything it needs to - the device is only partially created and the
- * IOMMU driver hasn't seen it yet, so it can't have a group. Thus we
- * need this delayed attachment dance. Once IOMMU probe ordering is sorted
- * to move the arch_setup_dma_ops() call later, all the notifier bits below
- * become unnecessary, and will go away.
- */
-struct iommu_dma_notifier_data {
-	struct list_head list;
-	struct device *dev;
-	const struct iommu_ops *ops;
-	u64 dma_base;
-	u64 size;
-};
-static LIST_HEAD(iommu_dma_masters);
-static DEFINE_MUTEX(iommu_dma_notifier_lock);
-
-static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,
-			   u64 dma_base, u64 size)
-{
-	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-
-	/*
-	 * If the IOMMU driver has the DMA domain support that we require,
-	 * then the IOMMU core will have already configured a group for this
-	 * device, and allocated the default domain for that group.
-	 */
-	if (!domain || iommu_dma_init_domain(domain, dma_base, size, dev)) {
-		pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
-			dev_name(dev));
-		return false;
-	}
-
-	dev->archdata.dma_ops = &iommu_dma_ops;
-	return true;
-}
-
-static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,
-			      u64 dma_base, u64 size)
-{
-	struct iommu_dma_notifier_data *iommudata;
-
-	iommudata = kzalloc(sizeof(*iommudata), GFP_KERNEL);
-	if (!iommudata)
-		return;
-
-	iommudata->dev = dev;
-	iommudata->ops = ops;
-	iommudata->dma_base = dma_base;
-	iommudata->size = size;
-
-	mutex_lock(&iommu_dma_notifier_lock);
-	list_add(&iommudata->list, &iommu_dma_masters);
-	mutex_unlock(&iommu_dma_notifier_lock);
-}
-
-static int __iommu_attach_notifier(struct notifier_block *nb,
-				   unsigned long action, void *data)
-{
-	struct iommu_dma_notifier_data *master, *tmp;
-
-	if (action != BUS_NOTIFY_BIND_DRIVER)
-		return 0;
-
-	mutex_lock(&iommu_dma_notifier_lock);
-	list_for_each_entry_safe(master, tmp, &iommu_dma_masters, list) {
-		if (data == master->dev && do_iommu_attach(master->dev,
-				master->ops, master->dma_base, master->size)) {
-			list_del(&master->list);
-			kfree(master);
-			break;
-		}
-	}
-	mutex_unlock(&iommu_dma_notifier_lock);
-	return 0;
-}
-
-static int __init register_iommu_dma_ops_notifier(struct bus_type *bus)
-{
-	struct notifier_block *nb = kzalloc(sizeof(*nb), GFP_KERNEL);
-	int ret;
-
-	if (!nb)
-		return -ENOMEM;
-
-	nb->notifier_call = __iommu_attach_notifier;
-
-	ret = bus_register_notifier(bus, nb);
-	if (ret) {
-		pr_warn("Failed to register DMA domain notifier; IOMMU DMA ops unavailable on bus '%s'\n",
-			bus->name);
-		kfree(nb);
-	}
-	return ret;
-}
-
 static int __init __iommu_dma_init(void)
 {
-	int ret;
-
-	ret = iommu_dma_init();
-	if (!ret)
-		ret = register_iommu_dma_ops_notifier(&platform_bus_type);
-	if (!ret)
-		ret = register_iommu_dma_ops_notifier(&amba_bustype);
-#ifdef CONFIG_PCI
-	if (!ret)
-		ret = register_iommu_dma_ops_notifier(&pci_bus_type);
-#endif
-	return ret;
+	return iommu_dma_init();
 }
 arch_initcall(__iommu_dma_init);
 
 static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 				  const struct iommu_ops *ops)
 {
-	struct iommu_group *group;
+	struct iommu_domain *domain;
 
 	if (!ops)
 		return;
+
 	/*
-	 * TODO: As a concession to the future, we're ready to handle being
-	 * called both early and late (i.e. after bus_add_device). Once all
-	 * the platform bus code is reworked to call us late and the notifier
-	 * junk above goes away, move the body of do_iommu_attach here.
+	 * The IOMMU core code allocates the default DMA domain, which the
+	 * underlying IOMMU driver needs to support via the dma-iommu layer.
 	 */
-	group = iommu_group_get(dev);
-	if (group) {
-		do_iommu_attach(dev, ops, dma_base, size);
-		iommu_group_put(group);
-	} else {
-		queue_iommu_attach(dev, ops, dma_base, size);
+	domain = iommu_get_domain_for_dev(dev);
+	if (!domain || iommu_dma_init_domain(domain, dma_base, size, dev)) {
+		pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
+			dev_name(dev));
+		return;
 	}
+
+	dev->archdata.dma_ops = &iommu_dma_ops;
 }
 
 void arch_teardown_dma_ops(struct device *dev)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 07/12] arm64: dma-mapping: Remove the notifier trick to handle early setting of dma_ops

[Sricharan R]

With arch_setup_dma_ops now being called late during device's probe after
the device's iommu is probed, the notifier trick required to handle the
early setup of dma_ops before the iommu group gets created is not
required. So removing the notifier's here.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
[rm: clean up even more]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 * No change

 arch/arm64/mm/dma-mapping.c | 132 ++++----------------------------------------
 1 file changed, 12 insertions(+), 120 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index ae9f817..beee5ce 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -803,140 +803,32 @@ static void __iommu_unmap_sg_attrs(struct device *dev,
 	.mapping_error = iommu_dma_mapping_error,
 };
 
-/*
- * TODO: Right now __iommu_setup_dma_ops() gets called too early to do
- * everything it needs to - the device is only partially created and the
- * IOMMU driver hasn't seen it yet, so it can't have a group. Thus we
- * need this delayed attachment dance. Once IOMMU probe ordering is sorted
- * to move the arch_setup_dma_ops() call later, all the notifier bits below
- * become unnecessary, and will go away.
- */
-struct iommu_dma_notifier_data {
-	struct list_head list;
-	struct device *dev;
-	const struct iommu_ops *ops;
-	u64 dma_base;
-	u64 size;
-};
-static LIST_HEAD(iommu_dma_masters);
-static DEFINE_MUTEX(iommu_dma_notifier_lock);
-
-static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,
-			   u64 dma_base, u64 size)
-{
-	struct iommu_domain *domain = iommu_get_domain_for_dev(dev);
-
-	/*
-	 * If the IOMMU driver has the DMA domain support that we require,
-	 * then the IOMMU core will have already configured a group for this
-	 * device, and allocated the default domain for that group.
-	 */
-	if (!domain || iommu_dma_init_domain(domain, dma_base, size, dev)) {
-		pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
-			dev_name(dev));
-		return false;
-	}
-
-	dev->archdata.dma_ops = &iommu_dma_ops;
-	return true;
-}
-
-static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops,
-			      u64 dma_base, u64 size)
-{
-	struct iommu_dma_notifier_data *iommudata;
-
-	iommudata = kzalloc(sizeof(*iommudata), GFP_KERNEL);
-	if (!iommudata)
-		return;
-
-	iommudata->dev = dev;
-	iommudata->ops = ops;
-	iommudata->dma_base = dma_base;
-	iommudata->size = size;
-
-	mutex_lock(&iommu_dma_notifier_lock);
-	list_add(&iommudata->list, &iommu_dma_masters);
-	mutex_unlock(&iommu_dma_notifier_lock);
-}
-
-static int __iommu_attach_notifier(struct notifier_block *nb,
-				   unsigned long action, void *data)
-{
-	struct iommu_dma_notifier_data *master, *tmp;
-
-	if (action != BUS_NOTIFY_BIND_DRIVER)
-		return 0;
-
-	mutex_lock(&iommu_dma_notifier_lock);
-	list_for_each_entry_safe(master, tmp, &iommu_dma_masters, list) {
-		if (data == master->dev && do_iommu_attach(master->dev,
-				master->ops, master->dma_base, master->size)) {
-			list_del(&master->list);
-			kfree(master);
-			break;
-		}
-	}
-	mutex_unlock(&iommu_dma_notifier_lock);
-	return 0;
-}
-
-static int __init register_iommu_dma_ops_notifier(struct bus_type *bus)
-{
-	struct notifier_block *nb = kzalloc(sizeof(*nb), GFP_KERNEL);
-	int ret;
-
-	if (!nb)
-		return -ENOMEM;
-
-	nb->notifier_call = __iommu_attach_notifier;
-
-	ret = bus_register_notifier(bus, nb);
-	if (ret) {
-		pr_warn("Failed to register DMA domain notifier; IOMMU DMA ops unavailable on bus '%s'\n",
-			bus->name);
-		kfree(nb);
-	}
-	return ret;
-}
-
 static int __init __iommu_dma_init(void)
 {
-	int ret;
-
-	ret = iommu_dma_init();
-	if (!ret)
-		ret = register_iommu_dma_ops_notifier(&platform_bus_type);
-	if (!ret)
-		ret = register_iommu_dma_ops_notifier(&amba_bustype);
-#ifdef CONFIG_PCI
-	if (!ret)
-		ret = register_iommu_dma_ops_notifier(&pci_bus_type);
-#endif
-	return ret;
+	return iommu_dma_init();
 }
 arch_initcall(__iommu_dma_init);
 
 static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 				  const struct iommu_ops *ops)
 {
-	struct iommu_group *group;
+	struct iommu_domain *domain;
 
 	if (!ops)
 		return;
+
 	/*
-	 * TODO: As a concession to the future, we're ready to handle being
-	 * called both early and late (i.e. after bus_add_device). Once all
-	 * the platform bus code is reworked to call us late and the notifier
-	 * junk above goes away, move the body of do_iommu_attach here.
+	 * The IOMMU core code allocates the default DMA domain, which the
+	 * underlying IOMMU driver needs to support via the dma-iommu layer.
 	 */
-	group = iommu_group_get(dev);
-	if (group) {
-		do_iommu_attach(dev, ops, dma_base, size);
-		iommu_group_put(group);
-	} else {
-		queue_iommu_attach(dev, ops, dma_base, size);
+	domain = iommu_get_domain_for_dev(dev);
+	if (!domain || iommu_dma_init_domain(domain, dma_base, size, dev)) {
+		pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
+			dev_name(dev));
+		return;
 	}
+
+	dev->archdata.dma_ops = &iommu_dma_ops;
 }
 
 void arch_teardown_dma_ops(struct device *dev)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Sricharan R]

From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>

Now that the appropriate ordering is enforced via profe-deferral of
masters in core code, rip it all out and bask in the simplicity.

Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
[Sricharan: Rebased on top of ACPI IORT SMMU series]
Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 * No change

 drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
 drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
 2 files changed, 10 insertions(+), 94 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 7d45d8b..7fc4e5f 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2724,51 +2724,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 	.probe	= arm_smmu_device_probe,
 	.remove	= arm_smmu_device_remove,
 };
+module_platform_driver(arm_smmu_driver);
 
-static int __init arm_smmu_init(void)
-{
-	static bool registered;
-	int ret = 0;
-
-	if (!registered) {
-		ret = platform_driver_register(&arm_smmu_driver);
-		registered = !ret;
-	}
-	return ret;
-}
-
-static void __exit arm_smmu_exit(void)
-{
-	return platform_driver_unregister(&arm_smmu_driver);
-}
-
-subsys_initcall(arm_smmu_init);
-module_exit(arm_smmu_exit);
-
-static int __init arm_smmu_of_init(struct device_node *np)
-{
-	int ret = arm_smmu_init();
-
-	if (ret)
-		return ret;
-
-	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
-		return -ENODEV;
-
-	return 0;
-}
-IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
-
-#ifdef CONFIG_ACPI
-static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
-{
-	if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
-		return arm_smmu_init();
-
-	return 0;
-}
-IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
-#endif
+IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
 
 MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
 MODULE_AUTHOR("Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>");
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 73a0a25..c86ae5f 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -2134,56 +2134,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 	.probe	= arm_smmu_device_probe,
 	.remove	= arm_smmu_device_remove,
 };
-
-static int __init arm_smmu_init(void)
-{
-	static bool registered;
-	int ret = 0;
-
-	if (!registered) {
-		ret = platform_driver_register(&arm_smmu_driver);
-		registered = !ret;
-	}
-	return ret;
-}
-
-static void __exit arm_smmu_exit(void)
-{
-	return platform_driver_unregister(&arm_smmu_driver);
-}
-
-subsys_initcall(arm_smmu_init);
-module_exit(arm_smmu_exit);
-
-static int __init arm_smmu_of_init(struct device_node *np)
-{
-	int ret = arm_smmu_init();
-
-	if (ret)
-		return ret;
-
-	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
-		return -ENODEV;
-
-	return 0;
-}
-IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
-IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
-
-#ifdef CONFIG_ACPI
-static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
-{
-	if (iort_node_match(ACPI_IORT_NODE_SMMU))
-		return arm_smmu_init();
-
-	return 0;
-}
-IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
-#endif
+module_platform_driver(arm_smmu_driver);
+
+IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
+IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
+IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
+IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
+IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
+IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);
 
 MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
 MODULE_AUTHOR("Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>");
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Sricharan R]

From: Robin Murphy <robin.murphy@arm.com>

Now that the appropriate ordering is enforced via profe-deferral of
masters in core code, rip it all out and bask in the simplicity.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[Sricharan: Rebased on top of ACPI IORT SMMU series]
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 * No change

 drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
 drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
 2 files changed, 10 insertions(+), 94 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 7d45d8b..7fc4e5f 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2724,51 +2724,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 	.probe	= arm_smmu_device_probe,
 	.remove	= arm_smmu_device_remove,
 };
+module_platform_driver(arm_smmu_driver);
 
-static int __init arm_smmu_init(void)
-{
-	static bool registered;
-	int ret = 0;
-
-	if (!registered) {
-		ret = platform_driver_register(&arm_smmu_driver);
-		registered = !ret;
-	}
-	return ret;
-}
-
-static void __exit arm_smmu_exit(void)
-{
-	return platform_driver_unregister(&arm_smmu_driver);
-}
-
-subsys_initcall(arm_smmu_init);
-module_exit(arm_smmu_exit);
-
-static int __init arm_smmu_of_init(struct device_node *np)
-{
-	int ret = arm_smmu_init();
-
-	if (ret)
-		return ret;
-
-	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
-		return -ENODEV;
-
-	return 0;
-}
-IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
-
-#ifdef CONFIG_ACPI
-static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
-{
-	if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
-		return arm_smmu_init();
-
-	return 0;
-}
-IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
-#endif
+IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
 
 MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 73a0a25..c86ae5f 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -2134,56 +2134,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 	.probe	= arm_smmu_device_probe,
 	.remove	= arm_smmu_device_remove,
 };
-
-static int __init arm_smmu_init(void)
-{
-	static bool registered;
-	int ret = 0;
-
-	if (!registered) {
-		ret = platform_driver_register(&arm_smmu_driver);
-		registered = !ret;
-	}
-	return ret;
-}
-
-static void __exit arm_smmu_exit(void)
-{
-	return platform_driver_unregister(&arm_smmu_driver);
-}
-
-subsys_initcall(arm_smmu_init);
-module_exit(arm_smmu_exit);
-
-static int __init arm_smmu_of_init(struct device_node *np)
-{
-	int ret = arm_smmu_init();
-
-	if (ret)
-		return ret;
-
-	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
-		return -ENODEV;
-
-	return 0;
-}
-IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
-IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
-IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
-
-#ifdef CONFIG_ACPI
-static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
-{
-	if (iort_node_match(ACPI_IORT_NODE_SMMU))
-		return arm_smmu_init();
-
-	return 0;
-}
-IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
-#endif
+module_platform_driver(arm_smmu_driver);
+
+IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
+IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
+IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
+IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
+IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
+IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);
 
 MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
 MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 09/12] ACPI/IORT: Add function to check SMMUs drivers presence

[Sricharan R]

From: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>

The IOMMU probe deferral implementation requires a mechanism to detect
if drivers for SMMU components are built-in in the kernel to detect
whether IOMMU configuration for a given device should be deferred (ie
SMMU drivers present but still not probed) or not (drivers not present).

Add a simple function to IORT to detect if SMMU drivers for SMMU
components managed by IORT are built-in in the kernel.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>
Cc: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Cc: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/acpi/arm64/iort.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index e0d2e6e..bf0ed09 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -523,6 +523,19 @@ static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
 	return ret;
 }
 
+static inline bool iort_iommu_driver_enabled(u8 type)
+{
+	switch (type) {
+	case ACPI_IORT_NODE_SMMU_V3:
+		return IS_BUILTIN(CONFIG_ARM_SMMU_V3);
+	case ACPI_IORT_NODE_SMMU:
+		return IS_BUILTIN(CONFIG_ARM_SMMU);
+	default:
+		pr_warn("IORT node type %u does not describe an SMMU\n", type);
+		return false;
+	}
+}
+
 static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
 					struct acpi_iort_node *node,
 					u32 streamid)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 09/12] ACPI/IORT: Add function to check SMMUs drivers presence

[Sricharan R]

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

The IOMMU probe deferral implementation requires a mechanism to detect
if drivers for SMMU components are built-in in the kernel to detect
whether IOMMU configuration for a given device should be deferred (ie
SMMU drivers present but still not probed) or not (drivers not present).

Add a simple function to IORT to detect if SMMU drivers for SMMU
components managed by IORT are built-in in the kernel.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sricharan R <sricharan@codeaurora.org>
---
 drivers/acpi/arm64/iort.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index e0d2e6e..bf0ed09 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -523,6 +523,19 @@ static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
 	return ret;
 }
 
+static inline bool iort_iommu_driver_enabled(u8 type)
+{
+	switch (type) {
+	case ACPI_IORT_NODE_SMMU_V3:
+		return IS_BUILTIN(CONFIG_ARM_SMMU_V3);
+	case ACPI_IORT_NODE_SMMU:
+		return IS_BUILTIN(CONFIG_ARM_SMMU);
+	default:
+		pr_warn("IORT node type %u does not describe an SMMU\n", type);
+		return false;
+	}
+}
+
 static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
 					struct acpi_iort_node *node,
 					u32 streamid)
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

[Sricharan R]

With all the DT based devices getting their dma ops configured
during probe time to have the right iommu setup, let us do the
same for acpi based devices as well.

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet. The dma_configure for the device is
now called from the generic device_attach callback just before the
bus/driver probe is called. This way, configuring the DMA ops for the
device would be called at the same place for all bus_types, hence the
deferred probing mechanism should work for all buses as well.

Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 * Removed the dma configuration for the pci devices in case of ACPI
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/acpi/glue.c        |  5 -----
 drivers/base/dma-mapping.c | 13 ++++++++++++-
 drivers/pci/probe.c        | 25 -------------------------
 3 files changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index fb19e1c..c05f241 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	struct list_head *physnode_list;
 	unsigned int node_id;
 	int retval = -EINVAL;
-	enum dev_dma_attr attr;
 
 	if (has_acpi_companion(dev)) {
 		if (acpi_dev) {
@@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	if (!has_acpi_companion(dev))
 		ACPI_COMPANION_SET(dev, acpi_dev);
 
-	attr = acpi_get_dma_attr(acpi_dev);
-	if (attr != DEV_DMA_NOT_SUPPORTED)
-		acpi_dma_configure(dev, attr);
-
 	acpi_physnode_link_name(physical_node_name, node_id);
 	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 				   physical_node_name);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index f82212c..294942d 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -7,6 +7,7 @@
  * This file is released under the GPLv2.
  */
 
+#include <linux/acpi.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
@@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
 {
 	struct device *_dev = dev;
 	int is_pci = dev_is_pci(dev);
+	enum dev_dma_attr attr;
 	int ret = 0;
 
 	if (is_pci) {
@@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
 			_dev = _dev->parent;
 	}
 
-	if (_dev->of_node)
+	if (_dev->of_node) {
 		ret = of_dma_configure(dev, _dev->of_node);
+	} else if (has_acpi_companion(_dev)) {
+		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
+
+		if (attr == DEV_DMA_NOT_SUPPORTED)
+			dev_warn(dev, "DMA not supported.\n");
+		else
+			acpi_dma_configure(dev, attr);
+	}
 
 	if (is_pci)
 		pci_put_host_bridge_device(_dev);
@@ -373,4 +383,5 @@ int dma_configure(struct device *dev)
 void dma_deconfigure(struct device *dev)
 {
 	of_dma_deconfigure(dev);
+	acpi_dma_deconfigure(dev);
 }
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 634d34e..b86e9b1 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1862,30 +1862,6 @@ static void pci_set_msi_domain(struct pci_dev *dev)
 	dev_set_msi_domain(&dev->dev, d);
 }
 
-/**
- * pci_dma_configure - Setup DMA configuration
- * @dev: ptr to pci_dev struct of the PCI device
- *
- * Function to update PCI devices's DMA configuration using the same
- * info from the OF node or ACPI node of host bridge's parent (if any).
- */
-static void pci_dma_configure(struct pci_dev *dev)
-{
-	struct device *bridge = pci_get_host_bridge_device(dev);
-
-	if (has_acpi_companion(bridge)) {
-		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
-		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
-
-		if (attr == DEV_DMA_NOT_SUPPORTED)
-			dev_warn(&dev->dev, "DMA not supported.\n");
-		else
-			acpi_dma_configure(&dev->dev, attr);
-	}
-
-	pci_put_host_bridge_device(bridge);
-}
-
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 {
 	int ret;
@@ -1899,7 +1875,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 	dev->dev.dma_mask = &dev->dma_mask;
 	dev->dev.dma_parms = &dev->dma_parms;
 	dev->dev.coherent_dma_mask = 0xffffffffull;
-	pci_dma_configure(dev);
 
 	pci_set_dma_max_seg_size(dev, 65536);
 	pci_set_dma_seg_boundary(dev, 0xffffffff);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

[Sricharan R]

With all the DT based devices getting their dma ops configured
during probe time to have the right iommu setup, let us do the
same for acpi based devices as well.

Configuring DMA ops at probe time will allow deferring device probe when
the IOMMU isn't available yet. The dma_configure for the device is
now called from the generic device_attach callback just before the
bus/driver probe is called. This way, configuring the DMA ops for the
device would be called at the same place for all bus_types, hence the
deferred probing mechanism should work for all buses as well.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 * Removed the dma configuration for the pci devices in case of ACPI
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/acpi/glue.c        |  5 -----
 drivers/base/dma-mapping.c | 13 ++++++++++++-
 drivers/pci/probe.c        | 25 -------------------------
 3 files changed, 12 insertions(+), 31 deletions(-)

diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
index fb19e1c..c05f241 100644
--- a/drivers/acpi/glue.c
+++ b/drivers/acpi/glue.c
@@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	struct list_head *physnode_list;
 	unsigned int node_id;
 	int retval = -EINVAL;
-	enum dev_dma_attr attr;
 
 	if (has_acpi_companion(dev)) {
 		if (acpi_dev) {
@@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
 	if (!has_acpi_companion(dev))
 		ACPI_COMPANION_SET(dev, acpi_dev);
 
-	attr = acpi_get_dma_attr(acpi_dev);
-	if (attr != DEV_DMA_NOT_SUPPORTED)
-		acpi_dma_configure(dev, attr);
-
 	acpi_physnode_link_name(physical_node_name, node_id);
 	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
 				   physical_node_name);
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index f82212c..294942d 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -7,6 +7,7 @@
  * This file is released under the GPLv2.
  */
 
+#include <linux/acpi.h>
 #include <linux/dma-mapping.h>
 #include <linux/export.h>
 #include <linux/gfp.h>
@@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
 {
 	struct device *_dev = dev;
 	int is_pci = dev_is_pci(dev);
+	enum dev_dma_attr attr;
 	int ret = 0;
 
 	if (is_pci) {
@@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
 			_dev = _dev->parent;
 	}
 
-	if (_dev->of_node)
+	if (_dev->of_node) {
 		ret = of_dma_configure(dev, _dev->of_node);
+	} else if (has_acpi_companion(_dev)) {
+		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
+
+		if (attr == DEV_DMA_NOT_SUPPORTED)
+			dev_warn(dev, "DMA not supported.\n");
+		else
+			acpi_dma_configure(dev, attr);
+	}
 
 	if (is_pci)
 		pci_put_host_bridge_device(_dev);
@@ -373,4 +383,5 @@ int dma_configure(struct device *dev)
 void dma_deconfigure(struct device *dev)
 {
 	of_dma_deconfigure(dev);
+	acpi_dma_deconfigure(dev);
 }
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 634d34e..b86e9b1 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1862,30 +1862,6 @@ static void pci_set_msi_domain(struct pci_dev *dev)
 	dev_set_msi_domain(&dev->dev, d);
 }
 
-/**
- * pci_dma_configure - Setup DMA configuration
- * @dev: ptr to pci_dev struct of the PCI device
- *
- * Function to update PCI devices's DMA configuration using the same
- * info from the OF node or ACPI node of host bridge's parent (if any).
- */
-static void pci_dma_configure(struct pci_dev *dev)
-{
-	struct device *bridge = pci_get_host_bridge_device(dev);
-
-	if (has_acpi_companion(bridge)) {
-		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
-		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
-
-		if (attr == DEV_DMA_NOT_SUPPORTED)
-			dev_warn(&dev->dev, "DMA not supported.\n");
-		else
-			acpi_dma_configure(&dev->dev, attr);
-	}
-
-	pci_put_host_bridge_device(bridge);
-}
-
 void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 {
 	int ret;
@@ -1899,7 +1875,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
 	dev->dev.dma_mask = &dev->dma_mask;
 	dev->dev.dma_parms = &dev->dma_parms;
 	dev->dev.coherent_dma_mask = 0xffffffffull;
-	pci_dma_configure(dev);
 
 	pci_set_dma_max_seg_size(dev, 65536);
 	pci_set_dma_seg_boundary(dev, 0xffffffff);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 11/12] drivers: acpi: Handle IOMMU lookup failure with deferred probing or error

[Sricharan R]

This is an equivalent to the DT's handling of the iommu master's probe
with deferred probing when the corrsponding iommu is not probed yet.
The lack of a registered IOMMU can be caused by the lack of a driver for
the IOMMU, the IOMMU device probe not having been performed yet, having
been deferred, or having failed.

The first case occurs when the firmware describes the bus master and
IOMMU topology correctly but no device driver exists for the IOMMU yet
or the device driver has not been compiled in. Return NULL, the caller
will configure the device without an IOMMU.

The second and third cases are handled by deferring the probe of the bus
master device which will eventually get reprobed after the IOMMU.

The last case is currently handled by deferring the probe of the bus
master device as well. A mechanism to either configure the bus master
device without an IOMMU or to fail the bus master device probe depending
on whether the IOMMU is optional or mandatory would be a good
enhancement.

Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 * Removed the dma configuration for the pci devices in case of ACPI
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/acpi/arm64/iort.c  | 25 ++++++++++++++++++++++++-
 drivers/acpi/scan.c        |  7 +++++--
 drivers/base/dma-mapping.c |  2 +-
 include/acpi/acpi_bus.h    |  2 +-
 include/linux/acpi.h       |  7 +++++--
 5 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index bf0ed09..d01bae8 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -550,8 +550,17 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
 			return NULL;
 
 		ops = iommu_get_instance(iort_fwnode);
+		/*
+		 * If the ops look-up fails, this means that either
+		 * the SMMU drivers have not been probed yet or that
+		 * the SMMU drivers are not built in the kernel;
+		 * Depending on whether the SMMU drivers are built-in
+		 * in the kernel or not, defer the IOMMU configuration
+		 * or just abort it.
+		 */
 		if (!ops)
-			return NULL;
+			return iort_iommu_driver_enabled(node->type) ?
+			       ERR_PTR(-EPROBE_DEFER) : NULL;
 
 		ret = arm_smmu_iort_xlate(dev, streamid, iort_fwnode, ops);
 	}
@@ -625,12 +634,26 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 
 		while (parent) {
 			ops = iort_iommu_xlate(dev, parent, streamid);
+			if (IS_ERR_OR_NULL(ops))
+				return ops;
 
 			parent = iort_node_get_id(node, &streamid,
 						  IORT_IOMMU_TYPE, i++);
 		}
 	}
 
+	/*
+	 * If we have reason to believe the IOMMU driver missed the initial
+	 * add_device callback for dev, replay it to get things in order.
+	 */
+	if (!IS_ERR_OR_NULL(ops) && ops->add_device &&
+	    dev->bus && !dev->iommu_group) {
+		int err = ops->add_device(dev);
+
+		if (err)
+			ops = ERR_PTR(err);
+	}
+
 	return ops;
 }
 
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 1926918..823b005 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1373,20 +1373,23 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
  * @dev: The pointer to the device
  * @attr: device dma attributes
  */
-void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
+int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
 {
 	const struct iommu_ops *iommu;
 
 	iort_set_dma_mask(dev);
 
 	iommu = iort_iommu_configure(dev);
-
+	if (IS_ERR(iommu))
+		return PTR_ERR(iommu);
 	/*
 	 * Assume dma valid range starts at 0 and covers the whole
 	 * coherent_dma_mask.
 	 */
 	arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, iommu,
 			   attr == DEV_DMA_COHERENT);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(acpi_dma_configure);
 
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 294942d..4b62a32 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -371,7 +371,7 @@ int dma_configure(struct device *dev)
 		if (attr == DEV_DMA_NOT_SUPPORTED)
 			dev_warn(dev, "DMA not supported.\n");
 		else
-			acpi_dma_configure(dev, attr);
+			ret = acpi_dma_configure(dev, attr);
 	}
 
 	if (is_pci)
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 4242c31..9aa762fe 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -573,7 +573,7 @@ struct acpi_pci_root {
 
 bool acpi_dma_supported(struct acpi_device *adev);
 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
-void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
+int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
 void acpi_dma_deconfigure(struct device *dev);
 
 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 5b36974..8b958b6 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -764,8 +764,11 @@ static inline enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
 	return DEV_DMA_NOT_SUPPORTED;
 }
 
-static inline void acpi_dma_configure(struct device *dev,
-				      enum dev_dma_attr attr) { }
+static inline int acpi_dma_configure(struct device *dev,
+				     enum dev_dma_attr attr)
+{
+	return 0;
+}
 
 static inline void acpi_dma_deconfigure(struct device *dev) { }
 
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 11/12] drivers: acpi: Handle IOMMU lookup failure with deferred probing or error

[Sricharan R]

This is an equivalent to the DT's handling of the iommu master's probe
with deferred probing when the corrsponding iommu is not probed yet.
The lack of a registered IOMMU can be caused by the lack of a driver for
the IOMMU, the IOMMU device probe not having been performed yet, having
been deferred, or having failed.

The first case occurs when the firmware describes the bus master and
IOMMU topology correctly but no device driver exists for the IOMMU yet
or the device driver has not been compiled in. Return NULL, the caller
will configure the device without an IOMMU.

The second and third cases are handled by deferring the probe of the bus
master device which will eventually get reprobed after the IOMMU.

The last case is currently handled by deferring the probe of the bus
master device as well. A mechanism to either configure the bus master
device without an IOMMU or to fail the bus master device probe depending
on whether the IOMMU is optional or mandatory would be a good
enhancement.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 * Removed the dma configuration for the pci devices in case of ACPI
   from pci_dma_configure which was hanging outside separately and
   doing it in dma_configure function itself.

 drivers/acpi/arm64/iort.c  | 25 ++++++++++++++++++++++++-
 drivers/acpi/scan.c        |  7 +++++--
 drivers/base/dma-mapping.c |  2 +-
 include/acpi/acpi_bus.h    |  2 +-
 include/linux/acpi.h       |  7 +++++--
 5 files changed, 36 insertions(+), 7 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index bf0ed09..d01bae8 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -550,8 +550,17 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
 			return NULL;
 
 		ops = iommu_get_instance(iort_fwnode);
+		/*
+		 * If the ops look-up fails, this means that either
+		 * the SMMU drivers have not been probed yet or that
+		 * the SMMU drivers are not built in the kernel;
+		 * Depending on whether the SMMU drivers are built-in
+		 * in the kernel or not, defer the IOMMU configuration
+		 * or just abort it.
+		 */
 		if (!ops)
-			return NULL;
+			return iort_iommu_driver_enabled(node->type) ?
+			       ERR_PTR(-EPROBE_DEFER) : NULL;
 
 		ret = arm_smmu_iort_xlate(dev, streamid, iort_fwnode, ops);
 	}
@@ -625,12 +634,26 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 
 		while (parent) {
 			ops = iort_iommu_xlate(dev, parent, streamid);
+			if (IS_ERR_OR_NULL(ops))
+				return ops;
 
 			parent = iort_node_get_id(node, &streamid,
 						  IORT_IOMMU_TYPE, i++);
 		}
 	}
 
+	/*
+	 * If we have reason to believe the IOMMU driver missed the initial
+	 * add_device callback for dev, replay it to get things in order.
+	 */
+	if (!IS_ERR_OR_NULL(ops) && ops->add_device &&
+	    dev->bus && !dev->iommu_group) {
+		int err = ops->add_device(dev);
+
+		if (err)
+			ops = ERR_PTR(err);
+	}
+
 	return ops;
 }
 
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index 1926918..823b005 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -1373,20 +1373,23 @@ enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
  * @dev: The pointer to the device
  * @attr: device dma attributes
  */
-void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
+int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr)
 {
 	const struct iommu_ops *iommu;
 
 	iort_set_dma_mask(dev);
 
 	iommu = iort_iommu_configure(dev);
-
+	if (IS_ERR(iommu))
+		return PTR_ERR(iommu);
 	/*
 	 * Assume dma valid range starts at 0 and covers the whole
 	 * coherent_dma_mask.
 	 */
 	arch_setup_dma_ops(dev, 0, dev->coherent_dma_mask + 1, iommu,
 			   attr == DEV_DMA_COHERENT);
+
+	return 0;
 }
 EXPORT_SYMBOL_GPL(acpi_dma_configure);
 
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 294942d..4b62a32 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -371,7 +371,7 @@ int dma_configure(struct device *dev)
 		if (attr == DEV_DMA_NOT_SUPPORTED)
 			dev_warn(dev, "DMA not supported.\n");
 		else
-			acpi_dma_configure(dev, attr);
+			ret = acpi_dma_configure(dev, attr);
 	}
 
 	if (is_pci)
diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h
index 4242c31..9aa762fe 100644
--- a/include/acpi/acpi_bus.h
+++ b/include/acpi/acpi_bus.h
@@ -573,7 +573,7 @@ struct acpi_pci_root {
 
 bool acpi_dma_supported(struct acpi_device *adev);
 enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev);
-void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
+int acpi_dma_configure(struct device *dev, enum dev_dma_attr attr);
 void acpi_dma_deconfigure(struct device *dev);
 
 struct acpi_device *acpi_find_child_device(struct acpi_device *parent,
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 5b36974..8b958b6 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -764,8 +764,11 @@ static inline enum dev_dma_attr acpi_get_dma_attr(struct acpi_device *adev)
 	return DEV_DMA_NOT_SUPPORTED;
 }
 
-static inline void acpi_dma_configure(struct device *dev,
-				      enum dev_dma_attr attr) { }
+static inline int acpi_dma_configure(struct device *dev,
+				     enum dev_dma_attr attr)
+{
+	return 0;
+}
 
 static inline void acpi_dma_deconfigure(struct device *dev) { }
 
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 12/12] ACPI/IORT: Remove linker section for IORT entries probing

[Sricharan R]

From: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>

The IORT linker section introduced by commit 34ceea275f62
("ACPI/IORT: Introduce linker section for IORT entries probing")
was needed to make sure SMMU drivers are registered (and therefore
probed) in the kernel before devices using the SMMU have a chance
to probe in turn.

Through the introduction of deferred IOMMU configuration the linker
section based IORT probing infrastructure is not needed any longer, in
that device/SMMU probe dependencies are managed through the probe
deferral mechanism, making the IORT linker section infrastructure
unused, so that it can be removed.

Remove the unused IORT linker section probing infrastructure
from the kernel to complete the ACPI IORT IOMMU configure probe
deferral mechanism implementation.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>
Cc: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
Cc: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
---
 drivers/acpi/arm64/iort.c         | 2 --
 include/asm-generic/vmlinux.lds.h | 1 -
 include/linux/acpi_iort.h         | 3 ---
 3 files changed, 6 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index d01bae8..ac45623 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -992,6 +992,4 @@ void __init acpi_iort_init(void)
 	}
 
 	iort_init_platform_devices();
-
-	acpi_probe_device_table(iort);
 }
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0968d13..9faa26c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -566,7 +566,6 @@
 	IRQCHIP_OF_MATCH_TABLE()					\
 	ACPI_PROBE_TABLE(irqchip)					\
 	ACPI_PROBE_TABLE(clksrc)					\
-	ACPI_PROBE_TABLE(iort)						\
 	EARLYCON_TABLE()
 
 #define INIT_TEXT							\
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index 77e0809..f167e1d04 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -52,7 +52,4 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 { return NULL; }
 #endif
 
-#define IORT_ACPI_DECLARE(name, table_id, fn)		\
-	ACPI_DECLARE_PROBE_ENTRY(iort, name, table_id, 0, NULL, 0, fn)
-
 #endif /* __ACPI_IORT_H__ */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

[PATCH V5 12/12] ACPI/IORT: Remove linker section for IORT entries probing

[Sricharan R]

From: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

The IORT linker section introduced by commit 34ceea275f62
("ACPI/IORT: Introduce linker section for IORT entries probing")
was needed to make sure SMMU drivers are registered (and therefore
probed) in the kernel before devices using the SMMU have a chance
to probe in turn.

Through the introduction of deferred IOMMU configuration the linker
section based IORT probing infrastructure is not needed any longer, in
that device/SMMU probe dependencies are managed through the probe
deferral mechanism, making the IORT linker section infrastructure
unused, so that it can be removed.

Remove the unused IORT linker section probing infrastructure
from the kernel to complete the ACPI IORT IOMMU configure probe
deferral mechanism implementation.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Sricharan R <sricharan@codeaurora.org>
---
 drivers/acpi/arm64/iort.c         | 2 --
 include/asm-generic/vmlinux.lds.h | 1 -
 include/linux/acpi_iort.h         | 3 ---
 3 files changed, 6 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index d01bae8..ac45623 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -992,6 +992,4 @@ void __init acpi_iort_init(void)
 	}
 
 	iort_init_platform_devices();
-
-	acpi_probe_device_table(iort);
 }
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 0968d13..9faa26c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -566,7 +566,6 @@
 	IRQCHIP_OF_MATCH_TABLE()					\
 	ACPI_PROBE_TABLE(irqchip)					\
 	ACPI_PROBE_TABLE(clksrc)					\
-	ACPI_PROBE_TABLE(iort)						\
 	EARLYCON_TABLE()
 
 #define INIT_TEXT							\
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index 77e0809..f167e1d04 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -52,7 +52,4 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
 { return NULL; }
 #endif
 
-#define IORT_ACPI_DECLARE(name, table_id, fn)		\
-	ACPI_DECLARE_PROBE_ENTRY(iort, name, table_id, 0, NULL, 0, fn)
-
 #endif /* __ACPI_IORT_H__ */
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation

Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Will Deacon]

On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
> From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> 
> Now that the appropriate ordering is enforced via profe-deferral of
> masters in core code, rip it all out and bask in the simplicity.
> 
> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> [Sricharan: Rebased on top of ACPI IORT SMMU series]
> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---
>  * No change
> 
>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>  2 files changed, 10 insertions(+), 94 deletions(-)

Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>

I can't wait to see this series merged. What's the plan for that?

Will

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Will Deacon]

On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
> From: Robin Murphy <robin.murphy@arm.com>
> 
> Now that the appropriate ordering is enforced via profe-deferral of
> masters in core code, rip it all out and bask in the simplicity.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> [Sricharan: Rebased on top of ACPI IORT SMMU series]
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  * No change
> 
>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>  2 files changed, 10 insertions(+), 94 deletions(-)

Acked-by: Will Deacon <will.deacon@arm.com>

I can't wait to see this series merged. What's the plan for that?

Will

Re: [PATCH V5 07/12] arm64: dma-mapping: Remove the notifier trick to handle early setting of dma_ops

[Will Deacon]

On Thu, Jan 19, 2017 at 08:35:51PM +0530, Sricharan R wrote:
> With arch_setup_dma_ops now being called late during device's probe after
> the device's iommu is probed, the notifier trick required to handle the
> early setup of dma_ops before the iommu group gets created is not
> required. So removing the notifier's here.
> 
> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> [rm: clean up even more]
> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> ---
>  * No change
> 
>  arch/arm64/mm/dma-mapping.c | 132 ++++----------------------------------------
>  1 file changed, 12 insertions(+), 120 deletions(-)

Acked-by: Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>

Will

[PATCH V5 07/12] arm64: dma-mapping: Remove the notifier trick to handle early setting of dma_ops

[Will Deacon]

On Thu, Jan 19, 2017 at 08:35:51PM +0530, Sricharan R wrote:
> With arch_setup_dma_ops now being called late during device's probe after
> the device's iommu is probed, the notifier trick required to handle the
> early setup of dma_ops before the iommu group gets created is not
> required. So removing the notifier's here.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> [rm: clean up even more]
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> ---
>  * No change
> 
>  arch/arm64/mm/dma-mapping.c | 132 ++++----------------------------------------
>  1 file changed, 12 insertions(+), 120 deletions(-)

Acked-by: Will Deacon <will.deacon@arm.com>

Will

Re: [PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 08:35:54PM +0530, Sricharan R wrote:
> With all the DT based devices getting their dma ops configured
> during probe time to have the right iommu setup, let us do the
> same for acpi based devices as well.
> 
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
> 
> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---
>  * Removed the dma configuration for the pci devices in case of ACPI
>    from pci_dma_configure which was hanging outside separately and
>    doing it in dma_configure function itself.
> 
>  drivers/acpi/glue.c        |  5 -----
>  drivers/base/dma-mapping.c | 13 ++++++++++++-
>  drivers/pci/probe.c        | 25 -------------------------
>  3 files changed, 12 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> index fb19e1c..c05f241 100644
> --- a/drivers/acpi/glue.c
> +++ b/drivers/acpi/glue.c
> @@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>  	struct list_head *physnode_list;
>  	unsigned int node_id;
>  	int retval = -EINVAL;
> -	enum dev_dma_attr attr;
>  
>  	if (has_acpi_companion(dev)) {
>  		if (acpi_dev) {
> @@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>  	if (!has_acpi_companion(dev))
>  		ACPI_COMPANION_SET(dev, acpi_dev);
>  
> -	attr = acpi_get_dma_attr(acpi_dev);
> -	if (attr != DEV_DMA_NOT_SUPPORTED)
> -		acpi_dma_configure(dev, attr);
> -
>  	acpi_physnode_link_name(physical_node_name, node_id);
>  	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
>  				   physical_node_name);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index f82212c..294942d 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -7,6 +7,7 @@
>   * This file is released under the GPLv2.
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
>  #include <linux/gfp.h>
> @@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
>  {
>  	struct device *_dev = dev;
>  	int is_pci = dev_is_pci(dev);
> +	enum dev_dma_attr attr;
>  	int ret = 0;
>  
>  	if (is_pci) {
> @@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
>  			_dev = _dev->parent;
>  	}
>  
> -	if (_dev->of_node)
> +	if (_dev->of_node) {
>  		ret = of_dma_configure(dev, _dev->of_node);
> +	} else if (has_acpi_companion(_dev)) {
> +		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
> +
> +		if (attr == DEV_DMA_NOT_SUPPORTED)
> +			dev_warn(dev, "DMA not supported.\n");

The changes you are making are correct but now this dev_warn spits hell
for non-pci devices that do not support DMA (ie they do not have a _CCA
on CONFIG_ACPI_CCA_REQUIRED systems), so you will have to remove it
given that this path is now shared.

Thanks,
Lorenzo

> +		else
> +			acpi_dma_configure(dev, attr);
> +	}
>  
>  	if (is_pci)
>  		pci_put_host_bridge_device(_dev);
> @@ -373,4 +383,5 @@ int dma_configure(struct device *dev)
>  void dma_deconfigure(struct device *dev)
>  {
>  	of_dma_deconfigure(dev);
> +	acpi_dma_deconfigure(dev);
>  }
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 634d34e..b86e9b1 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1862,30 +1862,6 @@ static void pci_set_msi_domain(struct pci_dev *dev)
>  	dev_set_msi_domain(&dev->dev, d);
>  }
>  
> -/**
> - * pci_dma_configure - Setup DMA configuration
> - * @dev: ptr to pci_dev struct of the PCI device
> - *
> - * Function to update PCI devices's DMA configuration using the same
> - * info from the OF node or ACPI node of host bridge's parent (if any).
> - */
> -static void pci_dma_configure(struct pci_dev *dev)
> -{
> -	struct device *bridge = pci_get_host_bridge_device(dev);
> -
> -	if (has_acpi_companion(bridge)) {
> -		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> -		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> -
> -		if (attr == DEV_DMA_NOT_SUPPORTED)
> -			dev_warn(&dev->dev, "DMA not supported.\n");
> -		else
> -			acpi_dma_configure(&dev->dev, attr);
> -	}
> -
> -	pci_put_host_bridge_device(bridge);
> -}
> -
>  void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>  {
>  	int ret;
> @@ -1899,7 +1875,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>  	dev->dev.dma_mask = &dev->dma_mask;
>  	dev->dev.dma_parms = &dev->dma_parms;
>  	dev->dev.coherent_dma_mask = 0xffffffffull;
> -	pci_dma_configure(dev);
>  
>  	pci_set_dma_max_seg_size(dev, 65536);
>  	pci_set_dma_seg_boundary(dev, 0xffffffff);
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

[PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 08:35:54PM +0530, Sricharan R wrote:
> With all the DT based devices getting their dma ops configured
> during probe time to have the right iommu setup, let us do the
> same for acpi based devices as well.
> 
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  * Removed the dma configuration for the pci devices in case of ACPI
>    from pci_dma_configure which was hanging outside separately and
>    doing it in dma_configure function itself.
> 
>  drivers/acpi/glue.c        |  5 -----
>  drivers/base/dma-mapping.c | 13 ++++++++++++-
>  drivers/pci/probe.c        | 25 -------------------------
>  3 files changed, 12 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
> index fb19e1c..c05f241 100644
> --- a/drivers/acpi/glue.c
> +++ b/drivers/acpi/glue.c
> @@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>  	struct list_head *physnode_list;
>  	unsigned int node_id;
>  	int retval = -EINVAL;
> -	enum dev_dma_attr attr;
>  
>  	if (has_acpi_companion(dev)) {
>  		if (acpi_dev) {
> @@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>  	if (!has_acpi_companion(dev))
>  		ACPI_COMPANION_SET(dev, acpi_dev);
>  
> -	attr = acpi_get_dma_attr(acpi_dev);
> -	if (attr != DEV_DMA_NOT_SUPPORTED)
> -		acpi_dma_configure(dev, attr);
> -
>  	acpi_physnode_link_name(physical_node_name, node_id);
>  	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
>  				   physical_node_name);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index f82212c..294942d 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -7,6 +7,7 @@
>   * This file is released under the GPLv2.
>   */
>  
> +#include <linux/acpi.h>
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
>  #include <linux/gfp.h>
> @@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
>  {
>  	struct device *_dev = dev;
>  	int is_pci = dev_is_pci(dev);
> +	enum dev_dma_attr attr;
>  	int ret = 0;
>  
>  	if (is_pci) {
> @@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
>  			_dev = _dev->parent;
>  	}
>  
> -	if (_dev->of_node)
> +	if (_dev->of_node) {
>  		ret = of_dma_configure(dev, _dev->of_node);
> +	} else if (has_acpi_companion(_dev)) {
> +		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
> +
> +		if (attr == DEV_DMA_NOT_SUPPORTED)
> +			dev_warn(dev, "DMA not supported.\n");

The changes you are making are correct but now this dev_warn spits hell
for non-pci devices that do not support DMA (ie they do not have a _CCA
on CONFIG_ACPI_CCA_REQUIRED systems), so you will have to remove it
given that this path is now shared.

Thanks,
Lorenzo

> +		else
> +			acpi_dma_configure(dev, attr);
> +	}
>  
>  	if (is_pci)
>  		pci_put_host_bridge_device(_dev);
> @@ -373,4 +383,5 @@ int dma_configure(struct device *dev)
>  void dma_deconfigure(struct device *dev)
>  {
>  	of_dma_deconfigure(dev);
> +	acpi_dma_deconfigure(dev);
>  }
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 634d34e..b86e9b1 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1862,30 +1862,6 @@ static void pci_set_msi_domain(struct pci_dev *dev)
>  	dev_set_msi_domain(&dev->dev, d);
>  }
>  
> -/**
> - * pci_dma_configure - Setup DMA configuration
> - * @dev: ptr to pci_dev struct of the PCI device
> - *
> - * Function to update PCI devices's DMA configuration using the same
> - * info from the OF node or ACPI node of host bridge's parent (if any).
> - */
> -static void pci_dma_configure(struct pci_dev *dev)
> -{
> -	struct device *bridge = pci_get_host_bridge_device(dev);
> -
> -	if (has_acpi_companion(bridge)) {
> -		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> -		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> -
> -		if (attr == DEV_DMA_NOT_SUPPORTED)
> -			dev_warn(&dev->dev, "DMA not supported.\n");
> -		else
> -			acpi_dma_configure(&dev->dev, attr);
> -	}
> -
> -	pci_put_host_bridge_device(bridge);
> -}
> -
>  void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>  {
>  	int ret;
> @@ -1899,7 +1875,6 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
>  	dev->dev.dma_mask = &dev->dma_mask;
>  	dev->dev.dma_parms = &dev->dma_parms;
>  	dev->dev.coherent_dma_mask = 0xffffffffull;
> -	pci_dma_configure(dev);
>  
>  	pci_set_dma_max_seg_size(dev, 65536);
>  	pci_set_dma_seg_boundary(dev, 0xffffffff);
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

Re: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 08:35:49PM +0530, Sricharan R wrote:
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
> 
> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>        |                         |
> pci_bus_add_device     (device_add/driver_register)
>        |                         |
> device_attach           device_initial_probe
>        |                         |
> __device_attach_driver    __device_attach_driver
>        |
> driver_probe_device
>        |
> really_probe
>        |
> dma_configure
> 
> Similarly on the device/driver_unregister path __device_release_driver is
> called which inturn calls dma_deconfigure.
> 
> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---
>  * Removed the dma configuration for the pci devices in case of DT
>    from pci_dma_configure which was hanging outside separately and
>    doing it in dma_configure function itself.

Rename the patch subject then, it is misleading.

Thanks,
Lorenzo

>  drivers/base/dd.c           |  9 +++++++++
>  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>  drivers/of/platform.c       |  5 +----
>  drivers/pci/probe.c         |  5 +----
>  include/linux/dma-mapping.h |  3 +++
>  5 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index a1fbf55..4882f06 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -19,6 +19,7 @@
>  
>  #include <linux/device.h>
>  #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
>  #include <linux/module.h>
>  #include <linux/kthread.h>
>  #include <linux/wait.h>
> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	if (ret)
>  		goto pinctrl_bind_failed;
>  
> +	ret = dma_configure(dev);
> +	if (ret)
> +		goto dma_failed;
> +
>  	if (driver_sysfs_add(dev)) {
>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>  			__func__, dev_name(dev));
> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	goto done;
>  
>  probe_failed:
> +	dma_deconfigure(dev);
> +dma_failed:
>  	if (dev->bus)
>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>  			drv->remove(dev);
>  
>  		device_links_driver_cleanup(dev);
> +		dma_deconfigure(dev);
> +
>  		devres_release_all(dev);
>  		dev->driver = NULL;
>  		dev_set_drvdata(dev, NULL);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf..dfe6fd7 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -10,6 +10,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
>  #include <linux/gfp.h>
> +#include <linux/of_device.h>
>  #include <linux/slab.h>
>  #include <linux/vmalloc.h>
>  
> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>  	vunmap(cpu_addr);
>  }
>  #endif
> +
> +/*
> + * Common configuration to enable DMA API use for a device
> + */
> +#include <linux/pci.h>
> +
> +int dma_configure(struct device *dev)
> +{
> +	struct device *_dev = dev;
> +	int is_pci = dev_is_pci(dev);
> +
> +	if (is_pci) {
> +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
> +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> +		    _dev->parent->of_node)
> +			_dev = _dev->parent;
> +	}
> +
> +	if (_dev->of_node)
> +		of_dma_configure(dev, _dev->of_node);
> +
> +	if (is_pci)
> +		pci_put_host_bridge_device(_dev);
> +
> +	return 0;
> +}
> +
> +void dma_deconfigure(struct device *dev)
> +{
> +	of_dma_deconfigure(dev);
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 57418f7..cf35030 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -22,6 +22,7 @@
>  #include <linux/slab.h>
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
> +#include <linux/of_iommu.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
>  
>  	dev->dev.bus = &platform_bus_type;
>  	dev->dev.platform_data = platform_data;
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  	of_msi_configure(&dev->dev, dev->dev.of_node);
>  
>  	if (of_device_add(dev) != 0) {
> -		of_dma_deconfigure(&dev->dev);
>  		platform_device_put(dev);
>  		goto err_clear_flag;
>  	}
> @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>  		dev_set_name(&dev->dev, "%s", bus_id);
>  	else
>  		of_device_make_bus_id(&dev->dev);
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  
>  	/* Allow the HW Peripheral ID to be overridden */
>  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
> @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
>  		amba_device_unregister(to_amba_device(dev));
>  #endif
>  
> -	of_dma_deconfigure(dev);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
>  	return 0;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index e164b5c..634d34e 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
>  {
>  	struct device *bridge = pci_get_host_bridge_device(dev);
>  
> -	if (IS_ENABLED(CONFIG_OF) &&
> -		bridge->parent && bridge->parent->of_node) {
> -			of_dma_configure(&dev->dev, bridge->parent->of_node);
> -	} else if (has_acpi_companion(bridge)) {
> +	if (has_acpi_companion(bridge)) {
>  		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
>  		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>  
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index abf685ed..b56320a 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
>  }
>  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>  
> +int dma_configure(struct device *dev);
> +void dma_deconfigure(struct device *dev);
> +
>  /*
>   * Managed DMA API
>   */
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 08:35:49PM +0530, Sricharan R wrote:
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
> 
> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>        |                         |
> pci_bus_add_device     (device_add/driver_register)
>        |                         |
> device_attach           device_initial_probe
>        |                         |
> __device_attach_driver    __device_attach_driver
>        |
> driver_probe_device
>        |
> really_probe
>        |
> dma_configure
> 
> Similarly on the device/driver_unregister path __device_release_driver is
> called which inturn calls dma_deconfigure.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  * Removed the dma configuration for the pci devices in case of DT
>    from pci_dma_configure which was hanging outside separately and
>    doing it in dma_configure function itself.

Rename the patch subject then, it is misleading.

Thanks,
Lorenzo

>  drivers/base/dd.c           |  9 +++++++++
>  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>  drivers/of/platform.c       |  5 +----
>  drivers/pci/probe.c         |  5 +----
>  include/linux/dma-mapping.h |  3 +++
>  5 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index a1fbf55..4882f06 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -19,6 +19,7 @@
>  
>  #include <linux/device.h>
>  #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
>  #include <linux/module.h>
>  #include <linux/kthread.h>
>  #include <linux/wait.h>
> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	if (ret)
>  		goto pinctrl_bind_failed;
>  
> +	ret = dma_configure(dev);
> +	if (ret)
> +		goto dma_failed;
> +
>  	if (driver_sysfs_add(dev)) {
>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>  			__func__, dev_name(dev));
> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	goto done;
>  
>  probe_failed:
> +	dma_deconfigure(dev);
> +dma_failed:
>  	if (dev->bus)
>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>  			drv->remove(dev);
>  
>  		device_links_driver_cleanup(dev);
> +		dma_deconfigure(dev);
> +
>  		devres_release_all(dev);
>  		dev->driver = NULL;
>  		dev_set_drvdata(dev, NULL);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf..dfe6fd7 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -10,6 +10,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
>  #include <linux/gfp.h>
> +#include <linux/of_device.h>
>  #include <linux/slab.h>
>  #include <linux/vmalloc.h>
>  
> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>  	vunmap(cpu_addr);
>  }
>  #endif
> +
> +/*
> + * Common configuration to enable DMA API use for a device
> + */
> +#include <linux/pci.h>
> +
> +int dma_configure(struct device *dev)
> +{
> +	struct device *_dev = dev;
> +	int is_pci = dev_is_pci(dev);
> +
> +	if (is_pci) {
> +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
> +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> +		    _dev->parent->of_node)
> +			_dev = _dev->parent;
> +	}
> +
> +	if (_dev->of_node)
> +		of_dma_configure(dev, _dev->of_node);
> +
> +	if (is_pci)
> +		pci_put_host_bridge_device(_dev);
> +
> +	return 0;
> +}
> +
> +void dma_deconfigure(struct device *dev)
> +{
> +	of_dma_deconfigure(dev);
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 57418f7..cf35030 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -22,6 +22,7 @@
>  #include <linux/slab.h>
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
> +#include <linux/of_iommu.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
>  
>  	dev->dev.bus = &platform_bus_type;
>  	dev->dev.platform_data = platform_data;
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  	of_msi_configure(&dev->dev, dev->dev.of_node);
>  
>  	if (of_device_add(dev) != 0) {
> -		of_dma_deconfigure(&dev->dev);
>  		platform_device_put(dev);
>  		goto err_clear_flag;
>  	}
> @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>  		dev_set_name(&dev->dev, "%s", bus_id);
>  	else
>  		of_device_make_bus_id(&dev->dev);
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  
>  	/* Allow the HW Peripheral ID to be overridden */
>  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
> @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
>  		amba_device_unregister(to_amba_device(dev));
>  #endif
>  
> -	of_dma_deconfigure(dev);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
>  	return 0;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index e164b5c..634d34e 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
>  {
>  	struct device *bridge = pci_get_host_bridge_device(dev);
>  
> -	if (IS_ENABLED(CONFIG_OF) &&
> -		bridge->parent && bridge->parent->of_node) {
> -			of_dma_configure(&dev->dev, bridge->parent->of_node);
> -	} else if (has_acpi_companion(bridge)) {
> +	if (has_acpi_companion(bridge)) {
>  		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
>  		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>  
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index abf685ed..b56320a 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
>  }
>  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>  
> +int dma_configure(struct device *dev);
> +void dma_deconfigure(struct device *dev);
> +
>  /*
>   * Managed DMA API
>   */
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
> From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> 
> Now that the appropriate ordering is enforced via profe-deferral of
> masters in core code, rip it all out and bask in the simplicity.
> 
> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
> [Sricharan: Rebased on top of ACPI IORT SMMU series]
> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
> ---
>  * No change

Well, a tad too early on the series for ACPI, aka if we bisect the
series here you would break ACPI.

Totally agree on the patch, but you should move it to the end of the
series.

Lorenzo

>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>  2 files changed, 10 insertions(+), 94 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 7d45d8b..7fc4e5f 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2724,51 +2724,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>  	.probe	= arm_smmu_device_probe,
>  	.remove	= arm_smmu_device_remove,
>  };
> +module_platform_driver(arm_smmu_driver);
>  
> -static int __init arm_smmu_init(void)
> -{
> -	static bool registered;
> -	int ret = 0;
> -
> -	if (!registered) {
> -		ret = platform_driver_register(&arm_smmu_driver);
> -		registered = !ret;
> -	}
> -	return ret;
> -}
> -
> -static void __exit arm_smmu_exit(void)
> -{
> -	return platform_driver_unregister(&arm_smmu_driver);
> -}
> -
> -subsys_initcall(arm_smmu_init);
> -module_exit(arm_smmu_exit);
> -
> -static int __init arm_smmu_of_init(struct device_node *np)
> -{
> -	int ret = arm_smmu_init();
> -
> -	if (ret)
> -		return ret;
> -
> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
> -		return -ENODEV;
> -
> -	return 0;
> -}
> -IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
> -
> -#ifdef CONFIG_ACPI
> -static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
> -{
> -	if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
> -		return arm_smmu_init();
> -
> -	return 0;
> -}
> -IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
> -#endif
> +IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>  
>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>  MODULE_AUTHOR("Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>");
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 73a0a25..c86ae5f 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -2134,56 +2134,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>  	.probe	= arm_smmu_device_probe,
>  	.remove	= arm_smmu_device_remove,
>  };
> -
> -static int __init arm_smmu_init(void)
> -{
> -	static bool registered;
> -	int ret = 0;
> -
> -	if (!registered) {
> -		ret = platform_driver_register(&arm_smmu_driver);
> -		registered = !ret;
> -	}
> -	return ret;
> -}
> -
> -static void __exit arm_smmu_exit(void)
> -{
> -	return platform_driver_unregister(&arm_smmu_driver);
> -}
> -
> -subsys_initcall(arm_smmu_init);
> -module_exit(arm_smmu_exit);
> -
> -static int __init arm_smmu_of_init(struct device_node *np)
> -{
> -	int ret = arm_smmu_init();
> -
> -	if (ret)
> -		return ret;
> -
> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
> -		return -ENODEV;
> -
> -	return 0;
> -}
> -IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
> -
> -#ifdef CONFIG_ACPI
> -static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
> -{
> -	if (iort_node_match(ACPI_IORT_NODE_SMMU))
> -		return arm_smmu_init();
> -
> -	return 0;
> -}
> -IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
> -#endif
> +module_platform_driver(arm_smmu_driver);
> +
> +IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
> +IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
> +IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
> +IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
> +IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
> +IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);
>  
>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
>  MODULE_AUTHOR("Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>");
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
> From: Robin Murphy <robin.murphy@arm.com>
> 
> Now that the appropriate ordering is enforced via profe-deferral of
> masters in core code, rip it all out and bask in the simplicity.
> 
> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
> [Sricharan: Rebased on top of ACPI IORT SMMU series]
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  * No change

Well, a tad too early on the series for ACPI, aka if we bisect the
series here you would break ACPI.

Totally agree on the patch, but you should move it to the end of the
series.

Lorenzo

>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>  2 files changed, 10 insertions(+), 94 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 7d45d8b..7fc4e5f 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -2724,51 +2724,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>  	.probe	= arm_smmu_device_probe,
>  	.remove	= arm_smmu_device_remove,
>  };
> +module_platform_driver(arm_smmu_driver);
>  
> -static int __init arm_smmu_init(void)
> -{
> -	static bool registered;
> -	int ret = 0;
> -
> -	if (!registered) {
> -		ret = platform_driver_register(&arm_smmu_driver);
> -		registered = !ret;
> -	}
> -	return ret;
> -}
> -
> -static void __exit arm_smmu_exit(void)
> -{
> -	return platform_driver_unregister(&arm_smmu_driver);
> -}
> -
> -subsys_initcall(arm_smmu_init);
> -module_exit(arm_smmu_exit);
> -
> -static int __init arm_smmu_of_init(struct device_node *np)
> -{
> -	int ret = arm_smmu_init();
> -
> -	if (ret)
> -		return ret;
> -
> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
> -		return -ENODEV;
> -
> -	return 0;
> -}
> -IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
> -
> -#ifdef CONFIG_ACPI
> -static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
> -{
> -	if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
> -		return arm_smmu_init();
> -
> -	return 0;
> -}
> -IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
> -#endif
> +IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>  
>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>  MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 73a0a25..c86ae5f 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -2134,56 +2134,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>  	.probe	= arm_smmu_device_probe,
>  	.remove	= arm_smmu_device_remove,
>  };
> -
> -static int __init arm_smmu_init(void)
> -{
> -	static bool registered;
> -	int ret = 0;
> -
> -	if (!registered) {
> -		ret = platform_driver_register(&arm_smmu_driver);
> -		registered = !ret;
> -	}
> -	return ret;
> -}
> -
> -static void __exit arm_smmu_exit(void)
> -{
> -	return platform_driver_unregister(&arm_smmu_driver);
> -}
> -
> -subsys_initcall(arm_smmu_init);
> -module_exit(arm_smmu_exit);
> -
> -static int __init arm_smmu_of_init(struct device_node *np)
> -{
> -	int ret = arm_smmu_init();
> -
> -	if (ret)
> -		return ret;
> -
> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
> -		return -ENODEV;
> -
> -	return 0;
> -}
> -IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
> -IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
> -
> -#ifdef CONFIG_ACPI
> -static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
> -{
> -	if (iort_node_match(ACPI_IORT_NODE_SMMU))
> -		return arm_smmu_init();
> -
> -	return 0;
> -}
> -IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
> -#endif
> +module_platform_driver(arm_smmu_driver);
> +
> +IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
> +IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
> +IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
> +IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
> +IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
> +IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);
>  
>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
>  MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
> -- 
> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
> 

Re: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Robin Murphy]

On 19/01/17 15:05, Sricharan R wrote:
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
> 
> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>        |                         |
> pci_bus_add_device     (device_add/driver_register)
>        |                         |
> device_attach           device_initial_probe
>        |                         |
> __device_attach_driver    __device_attach_driver
>        |
> driver_probe_device
>        |
> really_probe
>        |
> dma_configure
> 
> Similarly on the device/driver_unregister path __device_release_driver is
> called which inturn calls dma_deconfigure.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  * Removed the dma configuration for the pci devices in case of DT
>    from pci_dma_configure which was hanging outside separately and
>    doing it in dma_configure function itself.
> 
>  drivers/base/dd.c           |  9 +++++++++
>  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>  drivers/of/platform.c       |  5 +----
>  drivers/pci/probe.c         |  5 +----
>  include/linux/dma-mapping.h |  3 +++
>  5 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index a1fbf55..4882f06 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -19,6 +19,7 @@
>  
>  #include <linux/device.h>
>  #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
>  #include <linux/module.h>
>  #include <linux/kthread.h>
>  #include <linux/wait.h>
> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	if (ret)
>  		goto pinctrl_bind_failed;
>  
> +	ret = dma_configure(dev);
> +	if (ret)
> +		goto dma_failed;
> +
>  	if (driver_sysfs_add(dev)) {
>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>  			__func__, dev_name(dev));
> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	goto done;
>  
>  probe_failed:
> +	dma_deconfigure(dev);
> +dma_failed:
>  	if (dev->bus)
>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>  			drv->remove(dev);
>  
>  		device_links_driver_cleanup(dev);
> +		dma_deconfigure(dev);
> +
>  		devres_release_all(dev);
>  		dev->driver = NULL;
>  		dev_set_drvdata(dev, NULL);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf..dfe6fd7 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -10,6 +10,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
>  #include <linux/gfp.h>
> +#include <linux/of_device.h>
>  #include <linux/slab.h>
>  #include <linux/vmalloc.h>
>  
> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>  	vunmap(cpu_addr);
>  }
>  #endif
> +
> +/*
> + * Common configuration to enable DMA API use for a device
> + */
> +#include <linux/pci.h>
> +
> +int dma_configure(struct device *dev)
> +{
> +	struct device *_dev = dev;
> +	int is_pci = dev_is_pci(dev);
> +
> +	if (is_pci) {
> +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
> +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> +		    _dev->parent->of_node)
> +			_dev = _dev->parent;
> +	}
> +
> +	if (_dev->of_node)
> +		of_dma_configure(dev, _dev->of_node);
> +
> +	if (is_pci)
> +		pci_put_host_bridge_device(_dev);

There's a fun bug here - at this point _dev is the *parent* of the
bridge device, so we put the refcount on the wrong device (the platform
device representing the host controller, rather than the PCI device
representing its insides), which frees the guy we're in the middle of
probing, and things rapidly go wrong afterwards:

[    1.461026] bus: 'platform': driver_probe_device: matched device
40000000.pcie-controller with driver pci-host-generic
[    1.471640] bus: 'platform': really_probe: probing driver
pci-host-generic with device 40000000.pcie-controller
[    1.481678] OF: PCI: host bridge /pcie-controller@40000000 ranges:

...

[    2.158259] bus: 'pci': driver_probe_device: matched device
0000:02:10.0 with driver pcieport
[    2.166716] bus: 'pci': really_probe: probing driver pcieport with
device 0000:02:10.0
[    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
[    2.180978] pci 0000:02:10.0: Added to deferred list
[    2.185915] bus: 'pci': driver_probe_device: matched device
0000:02:1f.0 with driver pcieport
[    2.194366] bus: 'pci': really_probe: probing driver pcieport with
device 0000:02:1f.0
[    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
[    2.208625] pci 0000:02:1f.0: Added to deferred list
[    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
'���v����.pcie-controller'
[    2.222293] bus: 'platform': really_probe: bound device
���v����.pcie-controller to driver pci-host-generic
[    2.232041] Unable to handle kernel NULL pointer dereference at
virtual address 00000000

I recall debugging this same issue before, and I seem to have a local
version of this commit dated about 6 weeks ago where dma_configure()
looks like this:

--->8---
int dma_configure(struct device *dev)
{
	struct device *bridge = NULL, *dma_dev = dev;

	if (dev_is_pci(dev)) {
		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
		dma_dev = bridge->parent;
	}

	if (dma_dev && dma_dev->of_node) {
		of_dma_configure(dev, dma_dev->of_node);
	} else if (dma_dev && has_acpi_companion(dma_dev)) {
		struct acpi_device *adev = to_acpi_device_node(dma_dev->fwnode);
		enum dev_dma_attr attr = acpi_get_dma_attr(adev);

		if (attr == DEV_DMA_NOT_SUPPORTED)
			dev_warn(dev, "DMA not supported.\n");
		else
			arch_setup_dma_ops(dev, 0, 0, NULL,
					   attr == DEV_DMA_COHERENT);
	}

	if (bridge)
		pci_put_host_bridge_device(bridge);

	return 0;
}
---8<---

I have a feeling I was having a go at tidying up the "PCI hacks" from v4
myself, but other things ended up taking precedence.

Robin.

> +
> +	return 0;
> +}
> +
> +void dma_deconfigure(struct device *dev)
> +{
> +	of_dma_deconfigure(dev);
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 57418f7..cf35030 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -22,6 +22,7 @@
>  #include <linux/slab.h>
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
> +#include <linux/of_iommu.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
>  
>  	dev->dev.bus = &platform_bus_type;
>  	dev->dev.platform_data = platform_data;
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  	of_msi_configure(&dev->dev, dev->dev.of_node);
>  
>  	if (of_device_add(dev) != 0) {
> -		of_dma_deconfigure(&dev->dev);
>  		platform_device_put(dev);
>  		goto err_clear_flag;
>  	}
> @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>  		dev_set_name(&dev->dev, "%s", bus_id);
>  	else
>  		of_device_make_bus_id(&dev->dev);
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  
>  	/* Allow the HW Peripheral ID to be overridden */
>  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
> @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
>  		amba_device_unregister(to_amba_device(dev));
>  #endif
>  
> -	of_dma_deconfigure(dev);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
>  	return 0;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index e164b5c..634d34e 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
>  {
>  	struct device *bridge = pci_get_host_bridge_device(dev);
>  
> -	if (IS_ENABLED(CONFIG_OF) &&
> -		bridge->parent && bridge->parent->of_node) {
> -			of_dma_configure(&dev->dev, bridge->parent->of_node);
> -	} else if (has_acpi_companion(bridge)) {
> +	if (has_acpi_companion(bridge)) {
>  		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
>  		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>  
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index abf685ed..b56320a 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
>  }
>  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>  
> +int dma_configure(struct device *dev);
> +void dma_deconfigure(struct device *dev);
> +
>  /*
>   * Managed DMA API
>   */
> 

_______________________________________________
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iommu@lists.linux-foundation.org
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[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Robin Murphy]

On 19/01/17 15:05, Sricharan R wrote:
> Configuring DMA ops at probe time will allow deferring device probe when
> the IOMMU isn't available yet. The dma_configure for the device is
> now called from the generic device_attach callback just before the
> bus/driver probe is called. This way, configuring the DMA ops for the
> device would be called at the same place for all bus_types, hence the
> deferred probing mechanism should work for all buses as well.
> 
> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>        |                         |
> pci_bus_add_device     (device_add/driver_register)
>        |                         |
> device_attach           device_initial_probe
>        |                         |
> __device_attach_driver    __device_attach_driver
>        |
> driver_probe_device
>        |
> really_probe
>        |
> dma_configure
> 
> Similarly on the device/driver_unregister path __device_release_driver is
> called which inturn calls dma_deconfigure.
> 
> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> ---
>  * Removed the dma configuration for the pci devices in case of DT
>    from pci_dma_configure which was hanging outside separately and
>    doing it in dma_configure function itself.
> 
>  drivers/base/dd.c           |  9 +++++++++
>  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>  drivers/of/platform.c       |  5 +----
>  drivers/pci/probe.c         |  5 +----
>  include/linux/dma-mapping.h |  3 +++
>  5 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> index a1fbf55..4882f06 100644
> --- a/drivers/base/dd.c
> +++ b/drivers/base/dd.c
> @@ -19,6 +19,7 @@
>  
>  #include <linux/device.h>
>  #include <linux/delay.h>
> +#include <linux/dma-mapping.h>
>  #include <linux/module.h>
>  #include <linux/kthread.h>
>  #include <linux/wait.h>
> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	if (ret)
>  		goto pinctrl_bind_failed;
>  
> +	ret = dma_configure(dev);
> +	if (ret)
> +		goto dma_failed;
> +
>  	if (driver_sysfs_add(dev)) {
>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>  			__func__, dev_name(dev));
> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>  	goto done;
>  
>  probe_failed:
> +	dma_deconfigure(dev);
> +dma_failed:
>  	if (dev->bus)
>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>  			drv->remove(dev);
>  
>  		device_links_driver_cleanup(dev);
> +		dma_deconfigure(dev);
> +
>  		devres_release_all(dev);
>  		dev->driver = NULL;
>  		dev_set_drvdata(dev, NULL);
> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> index efd71cf..dfe6fd7 100644
> --- a/drivers/base/dma-mapping.c
> +++ b/drivers/base/dma-mapping.c
> @@ -10,6 +10,7 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/export.h>
>  #include <linux/gfp.h>
> +#include <linux/of_device.h>
>  #include <linux/slab.h>
>  #include <linux/vmalloc.h>
>  
> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>  	vunmap(cpu_addr);
>  }
>  #endif
> +
> +/*
> + * Common configuration to enable DMA API use for a device
> + */
> +#include <linux/pci.h>
> +
> +int dma_configure(struct device *dev)
> +{
> +	struct device *_dev = dev;
> +	int is_pci = dev_is_pci(dev);
> +
> +	if (is_pci) {
> +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
> +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> +		    _dev->parent->of_node)
> +			_dev = _dev->parent;
> +	}
> +
> +	if (_dev->of_node)
> +		of_dma_configure(dev, _dev->of_node);
> +
> +	if (is_pci)
> +		pci_put_host_bridge_device(_dev);

There's a fun bug here - at this point _dev is the *parent* of the
bridge device, so we put the refcount on the wrong device (the platform
device representing the host controller, rather than the PCI device
representing its insides), which frees the guy we're in the middle of
probing, and things rapidly go wrong afterwards:

[    1.461026] bus: 'platform': driver_probe_device: matched device
40000000.pcie-controller with driver pci-host-generic
[    1.471640] bus: 'platform': really_probe: probing driver
pci-host-generic with device 40000000.pcie-controller
[    1.481678] OF: PCI: host bridge /pcie-controller at 40000000 ranges:

...

[    2.158259] bus: 'pci': driver_probe_device: matched device
0000:02:10.0 with driver pcieport
[    2.166716] bus: 'pci': really_probe: probing driver pcieport with
device 0000:02:10.0
[    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
[    2.180978] pci 0000:02:10.0: Added to deferred list
[    2.185915] bus: 'pci': driver_probe_device: matched device
0000:02:1f.0 with driver pcieport
[    2.194366] bus: 'pci': really_probe: probing driver pcieport with
device 0000:02:1f.0
[    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
[    2.208625] pci 0000:02:1f.0: Added to deferred list
[    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
'???v????.pcie-controller'
[    2.222293] bus: 'platform': really_probe: bound device
???v????.pcie-controller to driver pci-host-generic
[    2.232041] Unable to handle kernel NULL pointer dereference at
virtual address 00000000

I recall debugging this same issue before, and I seem to have a local
version of this commit dated about 6 weeks ago where dma_configure()
looks like this:

--->8---
int dma_configure(struct device *dev)
{
	struct device *bridge = NULL, *dma_dev = dev;

	if (dev_is_pci(dev)) {
		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
		dma_dev = bridge->parent;
	}

	if (dma_dev && dma_dev->of_node) {
		of_dma_configure(dev, dma_dev->of_node);
	} else if (dma_dev && has_acpi_companion(dma_dev)) {
		struct acpi_device *adev = to_acpi_device_node(dma_dev->fwnode);
		enum dev_dma_attr attr = acpi_get_dma_attr(adev);

		if (attr == DEV_DMA_NOT_SUPPORTED)
			dev_warn(dev, "DMA not supported.\n");
		else
			arch_setup_dma_ops(dev, 0, 0, NULL,
					   attr == DEV_DMA_COHERENT);
	}

	if (bridge)
		pci_put_host_bridge_device(bridge);

	return 0;
}
---8<---

I have a feeling I was having a go@tidying up the "PCI hacks" from v4
myself, but other things ended up taking precedence.

Robin.

> +
> +	return 0;
> +}
> +
> +void dma_deconfigure(struct device *dev)
> +{
> +	of_dma_deconfigure(dev);
> +}
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 57418f7..cf35030 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -22,6 +22,7 @@
>  #include <linux/slab.h>
>  #include <linux/of_address.h>
>  #include <linux/of_device.h>
> +#include <linux/of_iommu.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_platform.h>
>  #include <linux/platform_device.h>
> @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
>  
>  	dev->dev.bus = &platform_bus_type;
>  	dev->dev.platform_data = platform_data;
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  	of_msi_configure(&dev->dev, dev->dev.of_node);
>  
>  	if (of_device_add(dev) != 0) {
> -		of_dma_deconfigure(&dev->dev);
>  		platform_device_put(dev);
>  		goto err_clear_flag;
>  	}
> @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
>  		dev_set_name(&dev->dev, "%s", bus_id);
>  	else
>  		of_device_make_bus_id(&dev->dev);
> -	of_dma_configure(&dev->dev, dev->dev.of_node);
>  
>  	/* Allow the HW Peripheral ID to be overridden */
>  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
> @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
>  		amba_device_unregister(to_amba_device(dev));
>  #endif
>  
> -	of_dma_deconfigure(dev);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED);
>  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
>  	return 0;
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index e164b5c..634d34e 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
>  {
>  	struct device *bridge = pci_get_host_bridge_device(dev);
>  
> -	if (IS_ENABLED(CONFIG_OF) &&
> -		bridge->parent && bridge->parent->of_node) {
> -			of_dma_configure(&dev->dev, bridge->parent->of_node);
> -	} else if (has_acpi_companion(bridge)) {
> +	if (has_acpi_companion(bridge)) {
>  		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
>  		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>  
> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index abf685ed..b56320a 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
>  }
>  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
>  
> +int dma_configure(struct device *dev);
> +void dma_deconfigure(struct device *dev);
> +
>  /*
>   * Managed DMA API
>   */
> 

Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Robin Murphy]

On 19/01/17 16:50, Lorenzo Pieralisi wrote:
> On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
>> From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
>>
>> Now that the appropriate ordering is enforced via profe-deferral of
>> masters in core code, rip it all out and bask in the simplicity.
>>
>> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
>> [Sricharan: Rebased on top of ACPI IORT SMMU series]
>> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>> ---
>>  * No change
> 
> Well, a tad too early on the series for ACPI, aka if we bisect the
> series here you would break ACPI.
> 
> Totally agree on the patch, but you should move it to the end of the
> series.

Indeed - I think a more appropriate ordering of the current patch
numbers would be:

1, 2, 3, 4, 9, 5+10 (squashed), 6, 11, 7, 8, 12

Robin.

> 
> Lorenzo
> 
>>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>>  2 files changed, 10 insertions(+), 94 deletions(-)
>>
>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
>> index 7d45d8b..7fc4e5f 100644
>> --- a/drivers/iommu/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm-smmu-v3.c
>> @@ -2724,51 +2724,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>>  	.probe	= arm_smmu_device_probe,
>>  	.remove	= arm_smmu_device_remove,
>>  };
>> +module_platform_driver(arm_smmu_driver);
>>  
>> -static int __init arm_smmu_init(void)
>> -{
>> -	static bool registered;
>> -	int ret = 0;
>> -
>> -	if (!registered) {
>> -		ret = platform_driver_register(&arm_smmu_driver);
>> -		registered = !ret;
>> -	}
>> -	return ret;
>> -}
>> -
>> -static void __exit arm_smmu_exit(void)
>> -{
>> -	return platform_driver_unregister(&arm_smmu_driver);
>> -}
>> -
>> -subsys_initcall(arm_smmu_init);
>> -module_exit(arm_smmu_exit);
>> -
>> -static int __init arm_smmu_of_init(struct device_node *np)
>> -{
>> -	int ret = arm_smmu_init();
>> -
>> -	if (ret)
>> -		return ret;
>> -
>> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
>> -		return -ENODEV;
>> -
>> -	return 0;
>> -}
>> -IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
>> -
>> -#ifdef CONFIG_ACPI
>> -static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
>> -{
>> -	if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
>> -		return arm_smmu_init();
>> -
>> -	return 0;
>> -}
>> -IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
>> -#endif
>> +IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>>  
>>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>>  MODULE_AUTHOR("Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>");
>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
>> index 73a0a25..c86ae5f 100644
>> --- a/drivers/iommu/arm-smmu.c
>> +++ b/drivers/iommu/arm-smmu.c
>> @@ -2134,56 +2134,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>>  	.probe	= arm_smmu_device_probe,
>>  	.remove	= arm_smmu_device_remove,
>>  };
>> -
>> -static int __init arm_smmu_init(void)
>> -{
>> -	static bool registered;
>> -	int ret = 0;
>> -
>> -	if (!registered) {
>> -		ret = platform_driver_register(&arm_smmu_driver);
>> -		registered = !ret;
>> -	}
>> -	return ret;
>> -}
>> -
>> -static void __exit arm_smmu_exit(void)
>> -{
>> -	return platform_driver_unregister(&arm_smmu_driver);
>> -}
>> -
>> -subsys_initcall(arm_smmu_init);
>> -module_exit(arm_smmu_exit);
>> -
>> -static int __init arm_smmu_of_init(struct device_node *np)
>> -{
>> -	int ret = arm_smmu_init();
>> -
>> -	if (ret)
>> -		return ret;
>> -
>> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
>> -		return -ENODEV;
>> -
>> -	return 0;
>> -}
>> -IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
>> -
>> -#ifdef CONFIG_ACPI
>> -static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
>> -{
>> -	if (iort_node_match(ACPI_IORT_NODE_SMMU))
>> -		return arm_smmu_init();
>> -
>> -	return 0;
>> -}
>> -IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
>> -#endif
>> +module_platform_driver(arm_smmu_driver);
>> +
>> +IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
>> +IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
>> +IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
>> +IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
>> +IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
>> +IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);
>>  
>>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
>>  MODULE_AUTHOR("Will Deacon <will.deacon-5wv7dgnIgG8@public.gmane.org>");
>> -- 
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
>>

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Robin Murphy]

On 19/01/17 16:50, Lorenzo Pieralisi wrote:
> On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>>
>> Now that the appropriate ordering is enforced via profe-deferral of
>> masters in core code, rip it all out and bask in the simplicity.
>>
>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>> [Sricharan: Rebased on top of ACPI IORT SMMU series]
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * No change
> 
> Well, a tad too early on the series for ACPI, aka if we bisect the
> series here you would break ACPI.
> 
> Totally agree on the patch, but you should move it to the end of the
> series.

Indeed - I think a more appropriate ordering of the current patch
numbers would be:

1, 2, 3, 4, 9, 5+10 (squashed), 6, 11, 7, 8, 12

Robin.

> 
> Lorenzo
> 
>>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>>  2 files changed, 10 insertions(+), 94 deletions(-)
>>
>> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
>> index 7d45d8b..7fc4e5f 100644
>> --- a/drivers/iommu/arm-smmu-v3.c
>> +++ b/drivers/iommu/arm-smmu-v3.c
>> @@ -2724,51 +2724,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>>  	.probe	= arm_smmu_device_probe,
>>  	.remove	= arm_smmu_device_remove,
>>  };
>> +module_platform_driver(arm_smmu_driver);
>>  
>> -static int __init arm_smmu_init(void)
>> -{
>> -	static bool registered;
>> -	int ret = 0;
>> -
>> -	if (!registered) {
>> -		ret = platform_driver_register(&arm_smmu_driver);
>> -		registered = !ret;
>> -	}
>> -	return ret;
>> -}
>> -
>> -static void __exit arm_smmu_exit(void)
>> -{
>> -	return platform_driver_unregister(&arm_smmu_driver);
>> -}
>> -
>> -subsys_initcall(arm_smmu_init);
>> -module_exit(arm_smmu_exit);
>> -
>> -static int __init arm_smmu_of_init(struct device_node *np)
>> -{
>> -	int ret = arm_smmu_init();
>> -
>> -	if (ret)
>> -		return ret;
>> -
>> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
>> -		return -ENODEV;
>> -
>> -	return 0;
>> -}
>> -IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", arm_smmu_of_init);
>> -
>> -#ifdef CONFIG_ACPI
>> -static int __init acpi_smmu_v3_init(struct acpi_table_header *table)
>> -{
>> -	if (iort_node_match(ACPI_IORT_NODE_SMMU_V3))
>> -		return arm_smmu_init();
>> -
>> -	return 0;
>> -}
>> -IORT_ACPI_DECLARE(arm_smmu_v3, ACPI_SIG_IORT, acpi_smmu_v3_init);
>> -#endif
>> +IOMMU_OF_DECLARE(arm_smmuv3, "arm,smmu-v3", NULL);
>>  
>>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMUv3 implementations");
>>  MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
>> index 73a0a25..c86ae5f 100644
>> --- a/drivers/iommu/arm-smmu.c
>> +++ b/drivers/iommu/arm-smmu.c
>> @@ -2134,56 +2134,14 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
>>  	.probe	= arm_smmu_device_probe,
>>  	.remove	= arm_smmu_device_remove,
>>  };
>> -
>> -static int __init arm_smmu_init(void)
>> -{
>> -	static bool registered;
>> -	int ret = 0;
>> -
>> -	if (!registered) {
>> -		ret = platform_driver_register(&arm_smmu_driver);
>> -		registered = !ret;
>> -	}
>> -	return ret;
>> -}
>> -
>> -static void __exit arm_smmu_exit(void)
>> -{
>> -	return platform_driver_unregister(&arm_smmu_driver);
>> -}
>> -
>> -subsys_initcall(arm_smmu_init);
>> -module_exit(arm_smmu_exit);
>> -
>> -static int __init arm_smmu_of_init(struct device_node *np)
>> -{
>> -	int ret = arm_smmu_init();
>> -
>> -	if (ret)
>> -		return ret;
>> -
>> -	if (!of_platform_device_create(np, NULL, platform_bus_type.dev_root))
>> -		return -ENODEV;
>> -
>> -	return 0;
>> -}
>> -IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", arm_smmu_of_init);
>> -IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", arm_smmu_of_init);
>> -
>> -#ifdef CONFIG_ACPI
>> -static int __init arm_smmu_acpi_init(struct acpi_table_header *table)
>> -{
>> -	if (iort_node_match(ACPI_IORT_NODE_SMMU))
>> -		return arm_smmu_init();
>> -
>> -	return 0;
>> -}
>> -IORT_ACPI_DECLARE(arm_smmu, ACPI_SIG_IORT, arm_smmu_acpi_init);
>> -#endif
>> +module_platform_driver(arm_smmu_driver);
>> +
>> +IOMMU_OF_DECLARE(arm_smmuv1, "arm,smmu-v1", NULL);
>> +IOMMU_OF_DECLARE(arm_smmuv2, "arm,smmu-v2", NULL);
>> +IOMMU_OF_DECLARE(arm_mmu400, "arm,mmu-400", NULL);
>> +IOMMU_OF_DECLARE(arm_mmu401, "arm,mmu-401", NULL);
>> +IOMMU_OF_DECLARE(arm_mmu500, "arm,mmu-500", NULL);
>> +IOMMU_OF_DECLARE(cavium_smmuv2, "cavium,smmu-v2", NULL);
>>  
>>  MODULE_DESCRIPTION("IOMMU API for ARM architected SMMU implementations");
>>  MODULE_AUTHOR("Will Deacon <will.deacon@arm.com>");
>> -- 
>> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
>>

Re: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 05:49:58PM +0000, Robin Murphy wrote:
> On 19/01/17 15:05, Sricharan R wrote:
> > Configuring DMA ops at probe time will allow deferring device probe when
> > the IOMMU isn't available yet. The dma_configure for the device is
> > now called from the generic device_attach callback just before the
> > bus/driver probe is called. This way, configuring the DMA ops for the
> > device would be called at the same place for all bus_types, hence the
> > deferred probing mechanism should work for all buses as well.
> > 
> > pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
> >        |                         |
> > pci_bus_add_device     (device_add/driver_register)
> >        |                         |
> > device_attach           device_initial_probe
> >        |                         |
> > __device_attach_driver    __device_attach_driver
> >        |
> > driver_probe_device
> >        |
> > really_probe
> >        |
> > dma_configure
> > 
> > Similarly on the device/driver_unregister path __device_release_driver is
> > called which inturn calls dma_deconfigure.
> > 
> > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> > ---
> >  * Removed the dma configuration for the pci devices in case of DT
> >    from pci_dma_configure which was hanging outside separately and
> >    doing it in dma_configure function itself.
> > 
> >  drivers/base/dd.c           |  9 +++++++++
> >  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
> >  drivers/of/platform.c       |  5 +----
> >  drivers/pci/probe.c         |  5 +----
> >  include/linux/dma-mapping.h |  3 +++
> >  5 files changed, 46 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> > index a1fbf55..4882f06 100644
> > --- a/drivers/base/dd.c
> > +++ b/drivers/base/dd.c
> > @@ -19,6 +19,7 @@
> >  
> >  #include <linux/device.h>
> >  #include <linux/delay.h>
> > +#include <linux/dma-mapping.h>
> >  #include <linux/module.h>
> >  #include <linux/kthread.h>
> >  #include <linux/wait.h>
> > @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
> >  	if (ret)
> >  		goto pinctrl_bind_failed;
> >  
> > +	ret = dma_configure(dev);
> > +	if (ret)
> > +		goto dma_failed;
> > +
> >  	if (driver_sysfs_add(dev)) {
> >  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
> >  			__func__, dev_name(dev));
> > @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
> >  	goto done;
> >  
> >  probe_failed:
> > +	dma_deconfigure(dev);
> > +dma_failed:
> >  	if (dev->bus)
> >  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
> >  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> > @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
> >  			drv->remove(dev);
> >  
> >  		device_links_driver_cleanup(dev);
> > +		dma_deconfigure(dev);
> > +
> >  		devres_release_all(dev);
> >  		dev->driver = NULL;
> >  		dev_set_drvdata(dev, NULL);
> > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> > index efd71cf..dfe6fd7 100644
> > --- a/drivers/base/dma-mapping.c
> > +++ b/drivers/base/dma-mapping.c
> > @@ -10,6 +10,7 @@
> >  #include <linux/dma-mapping.h>
> >  #include <linux/export.h>
> >  #include <linux/gfp.h>
> > +#include <linux/of_device.h>
> >  #include <linux/slab.h>
> >  #include <linux/vmalloc.h>
> >  
> > @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
> >  	vunmap(cpu_addr);
> >  }
> >  #endif
> > +
> > +/*
> > + * Common configuration to enable DMA API use for a device
> > + */
> > +#include <linux/pci.h>
> > +
> > +int dma_configure(struct device *dev)
> > +{
> > +	struct device *_dev = dev;
> > +	int is_pci = dev_is_pci(dev);
> > +
> > +	if (is_pci) {
> > +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
> > +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> > +		    _dev->parent->of_node)
> > +			_dev = _dev->parent;
> > +	}
> > +
> > +	if (_dev->of_node)
> > +		of_dma_configure(dev, _dev->of_node);
> > +
> > +	if (is_pci)
> > +		pci_put_host_bridge_device(_dev);
> 
> There's a fun bug here - at this point _dev is the *parent* of the
> bridge device, so we put the refcount on the wrong device (the platform
> device representing the host controller, rather than the PCI device
> representing its insides), which frees the guy we're in the middle of
> probing, and things rapidly go wrong afterwards:
> 
> [    1.461026] bus: 'platform': driver_probe_device: matched device
> 40000000.pcie-controller with driver pci-host-generic
> [    1.471640] bus: 'platform': really_probe: probing driver
> pci-host-generic with device 40000000.pcie-controller
> [    1.481678] OF: PCI: host bridge /pcie-controller@40000000 ranges:
> 
> ...
> 
> [    2.158259] bus: 'pci': driver_probe_device: matched device
> 0000:02:10.0 with driver pcieport
> [    2.166716] bus: 'pci': really_probe: probing driver pcieport with
> device 0000:02:10.0
> [    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
> [    2.180978] pci 0000:02:10.0: Added to deferred list
> [    2.185915] bus: 'pci': driver_probe_device: matched device
> 0000:02:1f.0 with driver pcieport
> [    2.194366] bus: 'pci': really_probe: probing driver pcieport with
> device 0000:02:1f.0
> [    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
> [    2.208625] pci 0000:02:1f.0: Added to deferred list
> [    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
> '���v����.pcie-controller'
> [    2.222293] bus: 'platform': really_probe: bound device
> ���v����.pcie-controller to driver pci-host-generic
> [    2.232041] Unable to handle kernel NULL pointer dereference at
> virtual address 00000000
> 
> I recall debugging this same issue before, and I seem to have a local
> version of this commit dated about 6 weeks ago where dma_configure()
> looks like this:
> 
> --->8---
> int dma_configure(struct device *dev)
> {
> 	struct device *bridge = NULL, *dma_dev = dev;
> 
> 	if (dev_is_pci(dev)) {
> 		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
> 		dma_dev = bridge->parent;

This would break ACPI, dma_dev would be NULL here, so from
this standpoint (ACPI) the current patch is correct (but those [dev,_dev]
should be renamed, they are extremely misleading so naming as
in this hunk, which fixes DT too, is very welcome).

On ACPI the DMA attributes are checked on the bridge's companion
(ie its associated acpi_device).

Thanks,
Lorenzo

> 	}
> 
> 	if (dma_dev && dma_dev->of_node) {
> 		of_dma_configure(dev, dma_dev->of_node);
> 	} else if (dma_dev && has_acpi_companion(dma_dev)) {
> 		struct acpi_device *adev = to_acpi_device_node(dma_dev->fwnode);
> 		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> 
> 		if (attr == DEV_DMA_NOT_SUPPORTED)
> 			dev_warn(dev, "DMA not supported.\n");
> 		else
> 			arch_setup_dma_ops(dev, 0, 0, NULL,
> 					   attr == DEV_DMA_COHERENT);
> 	}
> 
> 	if (bridge)
> 		pci_put_host_bridge_device(bridge);
> 
> 	return 0;
> }
> ---8<---
> 
> I have a feeling I was having a go at tidying up the "PCI hacks" from v4
> myself, but other things ended up taking precedence.
> 
> Robin.
> 
> > +
> > +	return 0;
> > +}
> > +
> > +void dma_deconfigure(struct device *dev)
> > +{
> > +	of_dma_deconfigure(dev);
> > +}
> > diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> > index 57418f7..cf35030 100644
> > --- a/drivers/of/platform.c
> > +++ b/drivers/of/platform.c
> > @@ -22,6 +22,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/of_address.h>
> >  #include <linux/of_device.h>
> > +#include <linux/of_iommu.h>
> >  #include <linux/of_irq.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/platform_device.h>
> > @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
> >  
> >  	dev->dev.bus = &platform_bus_type;
> >  	dev->dev.platform_data = platform_data;
> > -	of_dma_configure(&dev->dev, dev->dev.of_node);
> >  	of_msi_configure(&dev->dev, dev->dev.of_node);
> >  
> >  	if (of_device_add(dev) != 0) {
> > -		of_dma_deconfigure(&dev->dev);
> >  		platform_device_put(dev);
> >  		goto err_clear_flag;
> >  	}
> > @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> >  		dev_set_name(&dev->dev, "%s", bus_id);
> >  	else
> >  		of_device_make_bus_id(&dev->dev);
> > -	of_dma_configure(&dev->dev, dev->dev.of_node);
> >  
> >  	/* Allow the HW Peripheral ID to be overridden */
> >  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
> > @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
> >  		amba_device_unregister(to_amba_device(dev));
> >  #endif
> >  
> > -	of_dma_deconfigure(dev);
> >  	of_node_clear_flag(dev->of_node, OF_POPULATED);
> >  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
> >  	return 0;
> > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> > index e164b5c..634d34e 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
> >  {
> >  	struct device *bridge = pci_get_host_bridge_device(dev);
> >  
> > -	if (IS_ENABLED(CONFIG_OF) &&
> > -		bridge->parent && bridge->parent->of_node) {
> > -			of_dma_configure(&dev->dev, bridge->parent->of_node);
> > -	} else if (has_acpi_companion(bridge)) {
> > +	if (has_acpi_companion(bridge)) {
> >  		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> >  		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> >  
> > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> > index abf685ed..b56320a 100644
> > --- a/include/linux/dma-mapping.h
> > +++ b/include/linux/dma-mapping.h
> > @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
> >  }
> >  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
> >  
> > +int dma_configure(struct device *dev);
> > +void dma_deconfigure(struct device *dev);
> > +
> >  /*
> >   * Managed DMA API
> >   */
> > 
> 
_______________________________________________
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[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Lorenzo Pieralisi]

On Thu, Jan 19, 2017 at 05:49:58PM +0000, Robin Murphy wrote:
> On 19/01/17 15:05, Sricharan R wrote:
> > Configuring DMA ops at probe time will allow deferring device probe when
> > the IOMMU isn't available yet. The dma_configure for the device is
> > now called from the generic device_attach callback just before the
> > bus/driver probe is called. This way, configuring the DMA ops for the
> > device would be called at the same place for all bus_types, hence the
> > deferred probing mechanism should work for all buses as well.
> > 
> > pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
> >        |                         |
> > pci_bus_add_device     (device_add/driver_register)
> >        |                         |
> > device_attach           device_initial_probe
> >        |                         |
> > __device_attach_driver    __device_attach_driver
> >        |
> > driver_probe_device
> >        |
> > really_probe
> >        |
> > dma_configure
> > 
> > Similarly on the device/driver_unregister path __device_release_driver is
> > called which inturn calls dma_deconfigure.
> > 
> > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
> > ---
> >  * Removed the dma configuration for the pci devices in case of DT
> >    from pci_dma_configure which was hanging outside separately and
> >    doing it in dma_configure function itself.
> > 
> >  drivers/base/dd.c           |  9 +++++++++
> >  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
> >  drivers/of/platform.c       |  5 +----
> >  drivers/pci/probe.c         |  5 +----
> >  include/linux/dma-mapping.h |  3 +++
> >  5 files changed, 46 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
> > index a1fbf55..4882f06 100644
> > --- a/drivers/base/dd.c
> > +++ b/drivers/base/dd.c
> > @@ -19,6 +19,7 @@
> >  
> >  #include <linux/device.h>
> >  #include <linux/delay.h>
> > +#include <linux/dma-mapping.h>
> >  #include <linux/module.h>
> >  #include <linux/kthread.h>
> >  #include <linux/wait.h>
> > @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
> >  	if (ret)
> >  		goto pinctrl_bind_failed;
> >  
> > +	ret = dma_configure(dev);
> > +	if (ret)
> > +		goto dma_failed;
> > +
> >  	if (driver_sysfs_add(dev)) {
> >  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
> >  			__func__, dev_name(dev));
> > @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
> >  	goto done;
> >  
> >  probe_failed:
> > +	dma_deconfigure(dev);
> > +dma_failed:
> >  	if (dev->bus)
> >  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
> >  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
> > @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
> >  			drv->remove(dev);
> >  
> >  		device_links_driver_cleanup(dev);
> > +		dma_deconfigure(dev);
> > +
> >  		devres_release_all(dev);
> >  		dev->driver = NULL;
> >  		dev_set_drvdata(dev, NULL);
> > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
> > index efd71cf..dfe6fd7 100644
> > --- a/drivers/base/dma-mapping.c
> > +++ b/drivers/base/dma-mapping.c
> > @@ -10,6 +10,7 @@
> >  #include <linux/dma-mapping.h>
> >  #include <linux/export.h>
> >  #include <linux/gfp.h>
> > +#include <linux/of_device.h>
> >  #include <linux/slab.h>
> >  #include <linux/vmalloc.h>
> >  
> > @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
> >  	vunmap(cpu_addr);
> >  }
> >  #endif
> > +
> > +/*
> > + * Common configuration to enable DMA API use for a device
> > + */
> > +#include <linux/pci.h>
> > +
> > +int dma_configure(struct device *dev)
> > +{
> > +	struct device *_dev = dev;
> > +	int is_pci = dev_is_pci(dev);
> > +
> > +	if (is_pci) {
> > +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
> > +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
> > +		    _dev->parent->of_node)
> > +			_dev = _dev->parent;
> > +	}
> > +
> > +	if (_dev->of_node)
> > +		of_dma_configure(dev, _dev->of_node);
> > +
> > +	if (is_pci)
> > +		pci_put_host_bridge_device(_dev);
> 
> There's a fun bug here - at this point _dev is the *parent* of the
> bridge device, so we put the refcount on the wrong device (the platform
> device representing the host controller, rather than the PCI device
> representing its insides), which frees the guy we're in the middle of
> probing, and things rapidly go wrong afterwards:
> 
> [    1.461026] bus: 'platform': driver_probe_device: matched device
> 40000000.pcie-controller with driver pci-host-generic
> [    1.471640] bus: 'platform': really_probe: probing driver
> pci-host-generic with device 40000000.pcie-controller
> [    1.481678] OF: PCI: host bridge /pcie-controller at 40000000 ranges:
> 
> ...
> 
> [    2.158259] bus: 'pci': driver_probe_device: matched device
> 0000:02:10.0 with driver pcieport
> [    2.166716] bus: 'pci': really_probe: probing driver pcieport with
> device 0000:02:10.0
> [    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
> [    2.180978] pci 0000:02:10.0: Added to deferred list
> [    2.185915] bus: 'pci': driver_probe_device: matched device
> 0000:02:1f.0 with driver pcieport
> [    2.194366] bus: 'pci': really_probe: probing driver pcieport with
> device 0000:02:1f.0
> [    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
> [    2.208625] pci 0000:02:1f.0: Added to deferred list
> [    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
> '???v????.pcie-controller'
> [    2.222293] bus: 'platform': really_probe: bound device
> ???v????.pcie-controller to driver pci-host-generic
> [    2.232041] Unable to handle kernel NULL pointer dereference at
> virtual address 00000000
> 
> I recall debugging this same issue before, and I seem to have a local
> version of this commit dated about 6 weeks ago where dma_configure()
> looks like this:
> 
> --->8---
> int dma_configure(struct device *dev)
> {
> 	struct device *bridge = NULL, *dma_dev = dev;
> 
> 	if (dev_is_pci(dev)) {
> 		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
> 		dma_dev = bridge->parent;

This would break ACPI, dma_dev would be NULL here, so from
this standpoint (ACPI) the current patch is correct (but those [dev,_dev]
should be renamed, they are extremely misleading so naming as
in this hunk, which fixes DT too, is very welcome).

On ACPI the DMA attributes are checked on the bridge's companion
(ie its associated acpi_device).

Thanks,
Lorenzo

> 	}
> 
> 	if (dma_dev && dma_dev->of_node) {
> 		of_dma_configure(dev, dma_dev->of_node);
> 	} else if (dma_dev && has_acpi_companion(dma_dev)) {
> 		struct acpi_device *adev = to_acpi_device_node(dma_dev->fwnode);
> 		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> 
> 		if (attr == DEV_DMA_NOT_SUPPORTED)
> 			dev_warn(dev, "DMA not supported.\n");
> 		else
> 			arch_setup_dma_ops(dev, 0, 0, NULL,
> 					   attr == DEV_DMA_COHERENT);
> 	}
> 
> 	if (bridge)
> 		pci_put_host_bridge_device(bridge);
> 
> 	return 0;
> }
> ---8<---
> 
> I have a feeling I was having a go at tidying up the "PCI hacks" from v4
> myself, but other things ended up taking precedence.
> 
> Robin.
> 
> > +
> > +	return 0;
> > +}
> > +
> > +void dma_deconfigure(struct device *dev)
> > +{
> > +	of_dma_deconfigure(dev);
> > +}
> > diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> > index 57418f7..cf35030 100644
> > --- a/drivers/of/platform.c
> > +++ b/drivers/of/platform.c
> > @@ -22,6 +22,7 @@
> >  #include <linux/slab.h>
> >  #include <linux/of_address.h>
> >  #include <linux/of_device.h>
> > +#include <linux/of_iommu.h>
> >  #include <linux/of_irq.h>
> >  #include <linux/of_platform.h>
> >  #include <linux/platform_device.h>
> > @@ -186,11 +187,9 @@ static struct platform_device *of_platform_device_create_pdata(
> >  
> >  	dev->dev.bus = &platform_bus_type;
> >  	dev->dev.platform_data = platform_data;
> > -	of_dma_configure(&dev->dev, dev->dev.of_node);
> >  	of_msi_configure(&dev->dev, dev->dev.of_node);
> >  
> >  	if (of_device_add(dev) != 0) {
> > -		of_dma_deconfigure(&dev->dev);
> >  		platform_device_put(dev);
> >  		goto err_clear_flag;
> >  	}
> > @@ -248,7 +247,6 @@ static struct amba_device *of_amba_device_create(struct device_node *node,
> >  		dev_set_name(&dev->dev, "%s", bus_id);
> >  	else
> >  		of_device_make_bus_id(&dev->dev);
> > -	of_dma_configure(&dev->dev, dev->dev.of_node);
> >  
> >  	/* Allow the HW Peripheral ID to be overridden */
> >  	prop = of_get_property(node, "arm,primecell-periphid", NULL);
> > @@ -542,7 +540,6 @@ static int of_platform_device_destroy(struct device *dev, void *data)
> >  		amba_device_unregister(to_amba_device(dev));
> >  #endif
> >  
> > -	of_dma_deconfigure(dev);
> >  	of_node_clear_flag(dev->of_node, OF_POPULATED);
> >  	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
> >  	return 0;
> > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> > index e164b5c..634d34e 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -1873,10 +1873,7 @@ static void pci_dma_configure(struct pci_dev *dev)
> >  {
> >  	struct device *bridge = pci_get_host_bridge_device(dev);
> >  
> > -	if (IS_ENABLED(CONFIG_OF) &&
> > -		bridge->parent && bridge->parent->of_node) {
> > -			of_dma_configure(&dev->dev, bridge->parent->of_node);
> > -	} else if (has_acpi_companion(bridge)) {
> > +	if (has_acpi_companion(bridge)) {
> >  		struct acpi_device *adev = to_acpi_device_node(bridge->fwnode);
> >  		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
> >  
> > diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> > index abf685ed..b56320a 100644
> > --- a/include/linux/dma-mapping.h
> > +++ b/include/linux/dma-mapping.h
> > @@ -718,6 +718,9 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
> >  }
> >  #endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
> >  
> > +int dma_configure(struct device *dev);
> > +void dma_deconfigure(struct device *dev);
> > +
> >  /*
> >   * Managed DMA API
> >   */
> > 
> 

RE: [PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

[Sricharan]

Hi Lorenzo,

>On Thu, Jan 19, 2017 at 08:35:54PM +0530, Sricharan R wrote:
>> With all the DT based devices getting their dma ops configured
>> during probe time to have the right iommu setup, let us do the
>> same for acpi based devices as well.
>>
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * Removed the dma configuration for the pci devices in case of ACPI
>>    from pci_dma_configure which was hanging outside separately and
>>    doing it in dma_configure function itself.
>>
>>  drivers/acpi/glue.c        |  5 -----
>>  drivers/base/dma-mapping.c | 13 ++++++++++++-
>>  drivers/pci/probe.c        | 25 -------------------------
>>  3 files changed, 12 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
>> index fb19e1c..c05f241 100644
>> --- a/drivers/acpi/glue.c
>> +++ b/drivers/acpi/glue.c
>> @@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>  	struct list_head *physnode_list;
>>  	unsigned int node_id;
>>  	int retval = -EINVAL;
>> -	enum dev_dma_attr attr;
>>
>>  	if (has_acpi_companion(dev)) {
>>  		if (acpi_dev) {
>> @@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>  	if (!has_acpi_companion(dev))
>>  		ACPI_COMPANION_SET(dev, acpi_dev);
>>
>> -	attr = acpi_get_dma_attr(acpi_dev);
>> -	if (attr != DEV_DMA_NOT_SUPPORTED)
>> -		acpi_dma_configure(dev, attr);
>> -
>>  	acpi_physnode_link_name(physical_node_name, node_id);
>>  	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
>>  				   physical_node_name);
>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> index f82212c..294942d 100644
>> --- a/drivers/base/dma-mapping.c
>> +++ b/drivers/base/dma-mapping.c
>> @@ -7,6 +7,7 @@
>>   * This file is released under the GPLv2.
>>   */
>>
>> +#include <linux/acpi.h>
>>  #include <linux/dma-mapping.h>
>>  #include <linux/export.h>
>>  #include <linux/gfp.h>
>> @@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
>>  {
>>  	struct device *_dev = dev;
>>  	int is_pci = dev_is_pci(dev);
>> +	enum dev_dma_attr attr;
>>  	int ret = 0;
>>
>>  	if (is_pci) {
>> @@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
>>  			_dev = _dev->parent;
>>  	}
>>
>> -	if (_dev->of_node)
>> +	if (_dev->of_node) {
>>  		ret = of_dma_configure(dev, _dev->of_node);
>> +	} else if (has_acpi_companion(_dev)) {
>> +		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
>> +
>> +		if (attr == DEV_DMA_NOT_SUPPORTED)
>> +			dev_warn(dev, "DMA not supported.\n");
>
>The changes you are making are correct but now this dev_warn spits hell
>for non-pci devices that do not support DMA (ie they do not have a _CCA
>on CONFIG_ACPI_CCA_REQUIRED systems), so you will have to remove it
>given that this path is now shared.
>

ok, will remove this WARN now.

Regards,
 Sricharan

[PATCH V5 10/12] drivers: acpi: Configure acpi devices dma operation at probe time

[Sricharan]

Hi Lorenzo,

>On Thu, Jan 19, 2017 at 08:35:54PM +0530, Sricharan R wrote:
>> With all the DT based devices getting their dma ops configured
>> during probe time to have the right iommu setup, let us do the
>> same for acpi based devices as well.
>>
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * Removed the dma configuration for the pci devices in case of ACPI
>>    from pci_dma_configure which was hanging outside separately and
>>    doing it in dma_configure function itself.
>>
>>  drivers/acpi/glue.c        |  5 -----
>>  drivers/base/dma-mapping.c | 13 ++++++++++++-
>>  drivers/pci/probe.c        | 25 -------------------------
>>  3 files changed, 12 insertions(+), 31 deletions(-)
>>
>> diff --git a/drivers/acpi/glue.c b/drivers/acpi/glue.c
>> index fb19e1c..c05f241 100644
>> --- a/drivers/acpi/glue.c
>> +++ b/drivers/acpi/glue.c
>> @@ -176,7 +176,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>  	struct list_head *physnode_list;
>>  	unsigned int node_id;
>>  	int retval = -EINVAL;
>> -	enum dev_dma_attr attr;
>>
>>  	if (has_acpi_companion(dev)) {
>>  		if (acpi_dev) {
>> @@ -233,10 +232,6 @@ int acpi_bind_one(struct device *dev, struct acpi_device *acpi_dev)
>>  	if (!has_acpi_companion(dev))
>>  		ACPI_COMPANION_SET(dev, acpi_dev);
>>
>> -	attr = acpi_get_dma_attr(acpi_dev);
>> -	if (attr != DEV_DMA_NOT_SUPPORTED)
>> -		acpi_dma_configure(dev, attr);
>> -
>>  	acpi_physnode_link_name(physical_node_name, node_id);
>>  	retval = sysfs_create_link(&acpi_dev->dev.kobj, &dev->kobj,
>>  				   physical_node_name);
>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> index f82212c..294942d 100644
>> --- a/drivers/base/dma-mapping.c
>> +++ b/drivers/base/dma-mapping.c
>> @@ -7,6 +7,7 @@
>>   * This file is released under the GPLv2.
>>   */
>>
>> +#include <linux/acpi.h>
>>  #include <linux/dma-mapping.h>
>>  #include <linux/export.h>
>>  #include <linux/gfp.h>
>> @@ -352,6 +353,7 @@ int dma_configure(struct device *dev)
>>  {
>>  	struct device *_dev = dev;
>>  	int is_pci = dev_is_pci(dev);
>> +	enum dev_dma_attr attr;
>>  	int ret = 0;
>>
>>  	if (is_pci) {
>> @@ -361,8 +363,16 @@ int dma_configure(struct device *dev)
>>  			_dev = _dev->parent;
>>  	}
>>
>> -	if (_dev->of_node)
>> +	if (_dev->of_node) {
>>  		ret = of_dma_configure(dev, _dev->of_node);
>> +	} else if (has_acpi_companion(_dev)) {
>> +		attr = acpi_get_dma_attr(to_acpi_device_node(_dev->fwnode));
>> +
>> +		if (attr == DEV_DMA_NOT_SUPPORTED)
>> +			dev_warn(dev, "DMA not supported.\n");
>
>The changes you are making are correct but now this dev_warn spits hell
>for non-pci devices that do not support DMA (ie they do not have a _CCA
>on CONFIG_ACPI_CCA_REQUIRED systems), so you will have to remove it
>given that this path is now shared.
>

ok, will remove this WARN now.

Regards,
 Sricharan

RE: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan]

Hi Lorenzo,

>-----Original Message-----
>From: Lorenzo Pieralisi [mailto:lorenzo.pieralisi@arm.com]
>Sent: Thursday, January 19, 2017 10:18 PM
>To: Sricharan R <sricharan@codeaurora.org>
>Cc: robin.murphy@arm.com; will.deacon@arm.com; joro@8bytes.org; iommu@lists.linux-foundation.org; linux-arm-
>kernel@lists.infradead.org; linux-arm-msm@vger.kernel.org; m.szyprowski@samsung.com
>Subject: Re: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time
>
>On Thu, Jan 19, 2017 at 08:35:49PM +0530, Sricharan R wrote:
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>>        |                         |
>> pci_bus_add_device     (device_add/driver_register)
>>        |                         |
>> device_attach           device_initial_probe
>>        |                         |
>> __device_attach_driver    __device_attach_driver
>>        |
>> driver_probe_device
>>        |
>> really_probe
>>        |
>> dma_configure
>>
>> Similarly on the device/driver_unregister path __device_release_driver is
>> called which inturn calls dma_deconfigure.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * Removed the dma configuration for the pci devices in case of DT
>>    from pci_dma_configure which was hanging outside separately and
>>    doing it in dma_configure function itself.
>
>Rename the patch subject then, it is misleading.

Ha, infact the patch still does what it says. The above words were
to mention what was changed from V4 to V5. Sorry i should have
mentioned that explicitly.

Regards,
 Sricharan

[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan]

Hi Lorenzo,

>-----Original Message-----
>From: Lorenzo Pieralisi [mailto:lorenzo.pieralisi at arm.com]
>Sent: Thursday, January 19, 2017 10:18 PM
>To: Sricharan R <sricharan@codeaurora.org>
>Cc: robin.murphy at arm.com; will.deacon at arm.com; joro at 8bytes.org; iommu at lists.linux-foundation.org; linux-arm-
>kernel at lists.infradead.org; linux-arm-msm at vger.kernel.org; m.szyprowski at samsung.com
>Subject: Re: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time
>
>On Thu, Jan 19, 2017 at 08:35:49PM +0530, Sricharan R wrote:
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>>        |                         |
>> pci_bus_add_device     (device_add/driver_register)
>>        |                         |
>> device_attach           device_initial_probe
>>        |                         |
>> __device_attach_driver    __device_attach_driver
>>        |
>> driver_probe_device
>>        |
>> really_probe
>>        |
>> dma_configure
>>
>> Similarly on the device/driver_unregister path __device_release_driver is
>> called which inturn calls dma_deconfigure.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * Removed the dma configuration for the pci devices in case of DT
>>    from pci_dma_configure which was hanging outside separately and
>>    doing it in dma_configure function itself.
>
>Rename the patch subject then, it is misleading.

Ha, infact the patch still does what it says. The above words were
to mention what was changed from V4 to V5. Sorry i should have
mentioned that explicitly.

Regards,
 Sricharan

RE: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan]

Hi Robin,

>On 19/01/17 15:05, Sricharan R wrote:
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>>        |                         |
>> pci_bus_add_device     (device_add/driver_register)
>>        |                         |
>> device_attach           device_initial_probe
>>        |                         |
>> __device_attach_driver    __device_attach_driver
>>        |
>> driver_probe_device
>>        |
>> really_probe
>>        |
>> dma_configure
>>
>> Similarly on the device/driver_unregister path __device_release_driver is
>> called which inturn calls dma_deconfigure.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * Removed the dma configuration for the pci devices in case of DT
>>    from pci_dma_configure which was hanging outside separately and
>>    doing it in dma_configure function itself.
>>
>>  drivers/base/dd.c           |  9 +++++++++
>>  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>>  drivers/of/platform.c       |  5 +----
>>  drivers/pci/probe.c         |  5 +----
>>  include/linux/dma-mapping.h |  3 +++
>>  5 files changed, 46 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
>> index a1fbf55..4882f06 100644
>> --- a/drivers/base/dd.c
>> +++ b/drivers/base/dd.c
>> @@ -19,6 +19,7 @@
>>
>>  #include <linux/device.h>
>>  #include <linux/delay.h>
>> +#include <linux/dma-mapping.h>
>>  #include <linux/module.h>
>>  #include <linux/kthread.h>
>>  #include <linux/wait.h>
>> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  	if (ret)
>>  		goto pinctrl_bind_failed;
>>
>> +	ret = dma_configure(dev);
>> +	if (ret)
>> +		goto dma_failed;
>> +
>>  	if (driver_sysfs_add(dev)) {
>>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>>  			__func__, dev_name(dev));
>> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  	goto done;
>>
>>  probe_failed:
>> +	dma_deconfigure(dev);
>> +dma_failed:
>>  	if (dev->bus)
>>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
>> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>>  			drv->remove(dev);
>>
>>  		device_links_driver_cleanup(dev);
>> +		dma_deconfigure(dev);
>> +
>>  		devres_release_all(dev);
>>  		dev->driver = NULL;
>>  		dev_set_drvdata(dev, NULL);
>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> index efd71cf..dfe6fd7 100644
>> --- a/drivers/base/dma-mapping.c
>> +++ b/drivers/base/dma-mapping.c
>> @@ -10,6 +10,7 @@
>>  #include <linux/dma-mapping.h>
>>  #include <linux/export.h>
>>  #include <linux/gfp.h>
>> +#include <linux/of_device.h>
>>  #include <linux/slab.h>
>>  #include <linux/vmalloc.h>
>>
>> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>>  	vunmap(cpu_addr);
>>  }
>>  #endif
>> +
>> +/*
>> + * Common configuration to enable DMA API use for a device
>> + */
>> +#include <linux/pci.h>
>> +
>> +int dma_configure(struct device *dev)
>> +{
>> +	struct device *_dev = dev;
>> +	int is_pci = dev_is_pci(dev);
>> +
>> +	if (is_pci) {
>> +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
>> +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
>> +		    _dev->parent->of_node)
>> +			_dev = _dev->parent;
>> +	}
>> +
>> +	if (_dev->of_node)
>> +		of_dma_configure(dev, _dev->of_node);
>> +
>> +	if (is_pci)
>> +		pci_put_host_bridge_device(_dev);
>
>There's a fun bug here - at this point _dev is the *parent* of the
>bridge device, so we put the refcount on the wrong device (the platform
>device representing the host controller, rather than the PCI device
>representing its insides), which frees the guy we're in the middle of
>probing, and things rapidly go wrong afterwards:
>

ha my bad, right. I will change to fix this. I was testing this with a couple
of pci devices, but it did not show up. Thanks for pointing this out.
I will borrow the variable names from the hunk below. 

>[    1.461026] bus: 'platform': driver_probe_device: matched device
>40000000.pcie-controller with driver pci-host-generic
>[    1.471640] bus: 'platform': really_probe: probing driver
>pci-host-generic with device 40000000.pcie-controller
>[    1.481678] OF: PCI: host bridge /pcie-controller@40000000 ranges:
>
>...
>
>[    2.158259] bus: 'pci': driver_probe_device: matched device
>0000:02:10.0 with driver pcieport
>[    2.166716] bus: 'pci': really_probe: probing driver pcieport with
>device 0000:02:10.0
>[    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
>[    2.180978] pci 0000:02:10.0: Added to deferred list
>[    2.185915] bus: 'pci': driver_probe_device: matched device
>0000:02:1f.0 with driver pcieport
>[    2.194366] bus: 'pci': really_probe: probing driver pcieport with
>device 0000:02:1f.0
>[    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
>[    2.208625] pci 0000:02:1f.0: Added to deferred list
>[    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
>'���v����.pcie-controller'
>[    2.222293] bus: 'platform': really_probe: bound device
>���v����.pcie-controller to driver pci-host-generic
>[    2.232041] Unable to handle kernel NULL pointer dereference at
>virtual address 00000000
>
>I recall debugging this same issue before, and I seem to have a local
>version of this commit dated about 6 weeks ago where dma_configure()
>looks like this:
>
>--->8---
>int dma_configure(struct device *dev)
>{
>	struct device *bridge = NULL, *dma_dev = dev;
>
>	if (dev_is_pci(dev)) {
>		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
>		dma_dev = bridge->parent;
>	}
>
>	if (dma_dev && dma_dev->of_node) {
>		of_dma_configure(dev, dma_dev->of_node);
>	} else if (dma_dev && has_acpi_companion(dma_dev)) {
>		struct acpi_device *adev = to_acpi_device_node(dma_dev->fwnode);
>		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>
>		if (attr == DEV_DMA_NOT_SUPPORTED)
>			dev_warn(dev, "DMA not supported.\n");
>		else
>			arch_setup_dma_ops(dev, 0, 0, NULL,
>					   attr == DEV_DMA_COHERENT);
>	}
>
>	if (bridge)
>		pci_put_host_bridge_device(bridge);
>
>	return 0;
>}
>---8<---
>
>I have a feeling I was having a go at tidying up the "PCI hacks" from v4
>myself, but other things ended up taking precedence.
>

Sure, i will repost with borrowing the names.

Regards,
 Sricharan

_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan]

Hi Robin,

>On 19/01/17 15:05, Sricharan R wrote:
>> Configuring DMA ops at probe time will allow deferring device probe when
>> the IOMMU isn't available yet. The dma_configure for the device is
>> now called from the generic device_attach callback just before the
>> bus/driver probe is called. This way, configuring the DMA ops for the
>> device would be called at the same place for all bus_types, hence the
>> deferred probing mechanism should work for all buses as well.
>>
>> pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>>        |                         |
>> pci_bus_add_device     (device_add/driver_register)
>>        |                         |
>> device_attach           device_initial_probe
>>        |                         |
>> __device_attach_driver    __device_attach_driver
>>        |
>> driver_probe_device
>>        |
>> really_probe
>>        |
>> dma_configure
>>
>> Similarly on the device/driver_unregister path __device_release_driver is
>> called which inturn calls dma_deconfigure.
>>
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * Removed the dma configuration for the pci devices in case of DT
>>    from pci_dma_configure which was hanging outside separately and
>>    doing it in dma_configure function itself.
>>
>>  drivers/base/dd.c           |  9 +++++++++
>>  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>>  drivers/of/platform.c       |  5 +----
>>  drivers/pci/probe.c         |  5 +----
>>  include/linux/dma-mapping.h |  3 +++
>>  5 files changed, 46 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/base/dd.c b/drivers/base/dd.c
>> index a1fbf55..4882f06 100644
>> --- a/drivers/base/dd.c
>> +++ b/drivers/base/dd.c
>> @@ -19,6 +19,7 @@
>>
>>  #include <linux/device.h>
>>  #include <linux/delay.h>
>> +#include <linux/dma-mapping.h>
>>  #include <linux/module.h>
>>  #include <linux/kthread.h>
>>  #include <linux/wait.h>
>> @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  	if (ret)
>>  		goto pinctrl_bind_failed;
>>
>> +	ret = dma_configure(dev);
>> +	if (ret)
>> +		goto dma_failed;
>> +
>>  	if (driver_sysfs_add(dev)) {
>>  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>>  			__func__, dev_name(dev));
>> @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>>  	goto done;
>>
>>  probe_failed:
>> +	dma_deconfigure(dev);
>> +dma_failed:
>>  	if (dev->bus)
>>  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>>  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
>> @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>>  			drv->remove(dev);
>>
>>  		device_links_driver_cleanup(dev);
>> +		dma_deconfigure(dev);
>> +
>>  		devres_release_all(dev);
>>  		dev->driver = NULL;
>>  		dev_set_drvdata(dev, NULL);
>> diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> index efd71cf..dfe6fd7 100644
>> --- a/drivers/base/dma-mapping.c
>> +++ b/drivers/base/dma-mapping.c
>> @@ -10,6 +10,7 @@
>>  #include <linux/dma-mapping.h>
>>  #include <linux/export.h>
>>  #include <linux/gfp.h>
>> +#include <linux/of_device.h>
>>  #include <linux/slab.h>
>>  #include <linux/vmalloc.h>
>>
>> @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>>  	vunmap(cpu_addr);
>>  }
>>  #endif
>> +
>> +/*
>> + * Common configuration to enable DMA API use for a device
>> + */
>> +#include <linux/pci.h>
>> +
>> +int dma_configure(struct device *dev)
>> +{
>> +	struct device *_dev = dev;
>> +	int is_pci = dev_is_pci(dev);
>> +
>> +	if (is_pci) {
>> +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
>> +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
>> +		    _dev->parent->of_node)
>> +			_dev = _dev->parent;
>> +	}
>> +
>> +	if (_dev->of_node)
>> +		of_dma_configure(dev, _dev->of_node);
>> +
>> +	if (is_pci)
>> +		pci_put_host_bridge_device(_dev);
>
>There's a fun bug here - at this point _dev is the *parent* of the
>bridge device, so we put the refcount on the wrong device (the platform
>device representing the host controller, rather than the PCI device
>representing its insides), which frees the guy we're in the middle of
>probing, and things rapidly go wrong afterwards:
>

ha my bad, right. I will change to fix this. I was testing this with a couple
of pci devices, but it did not show up. Thanks for pointing this out.
I will borrow the variable names from the hunk below. 

>[    1.461026] bus: 'platform': driver_probe_device: matched device
>40000000.pcie-controller with driver pci-host-generic
>[    1.471640] bus: 'platform': really_probe: probing driver
>pci-host-generic with device 40000000.pcie-controller
>[    1.481678] OF: PCI: host bridge /pcie-controller at 40000000 ranges:
>
>...
>
>[    2.158259] bus: 'pci': driver_probe_device: matched device
>0000:02:10.0 with driver pcieport
>[    2.166716] bus: 'pci': really_probe: probing driver pcieport with
>device 0000:02:10.0
>[    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
>[    2.180978] pci 0000:02:10.0: Added to deferred list
>[    2.185915] bus: 'pci': driver_probe_device: matched device
>0000:02:1f.0 with driver pcieport
>[    2.194366] bus: 'pci': really_probe: probing driver pcieport with
>device 0000:02:1f.0
>[    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
>[    2.208625] pci 0000:02:1f.0: Added to deferred list
>[    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
>'???v????.pcie-controller'
>[    2.222293] bus: 'platform': really_probe: bound device
>???v????.pcie-controller to driver pci-host-generic
>[    2.232041] Unable to handle kernel NULL pointer dereference at
>virtual address 00000000
>
>I recall debugging this same issue before, and I seem to have a local
>version of this commit dated about 6 weeks ago where dma_configure()
>looks like this:
>
>--->8---
>int dma_configure(struct device *dev)
>{
>	struct device *bridge = NULL, *dma_dev = dev;
>
>	if (dev_is_pci(dev)) {
>		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
>		dma_dev = bridge->parent;
>	}
>
>	if (dma_dev && dma_dev->of_node) {
>		of_dma_configure(dev, dma_dev->of_node);
>	} else if (dma_dev && has_acpi_companion(dma_dev)) {
>		struct acpi_device *adev = to_acpi_device_node(dma_dev->fwnode);
>		enum dev_dma_attr attr = acpi_get_dma_attr(adev);
>
>		if (attr == DEV_DMA_NOT_SUPPORTED)
>			dev_warn(dev, "DMA not supported.\n");
>		else
>			arch_setup_dma_ops(dev, 0, 0, NULL,
>					   attr == DEV_DMA_COHERENT);
>	}
>
>	if (bridge)
>		pci_put_host_bridge_device(bridge);
>
>	return 0;
>}
>---8<---
>
>I have a feeling I was having a go at tidying up the "PCI hacks" from v4
>myself, but other things ended up taking precedence.
>

Sure, i will repost with borrowing the names.

Regards,
 Sricharan

RE: [PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan]

Hi,

>
>> > pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>> >        |                         |
>> > pci_bus_add_device     (device_add/driver_register)
>> >        |                         |
>> > device_attach           device_initial_probe
>> >        |                         |
>> > __device_attach_driver    __device_attach_driver
>> >        |
>> > driver_probe_device
>> >        |
>> > really_probe
>> >        |
>> > dma_configure
>> >
>> > Similarly on the device/driver_unregister path __device_release_driver is
>> > called which inturn calls dma_deconfigure.
>> >
>> > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> > ---
>> >  * Removed the dma configuration for the pci devices in case of DT
>> >    from pci_dma_configure which was hanging outside separately and
>> >    doing it in dma_configure function itself.
>> >
>> >  drivers/base/dd.c           |  9 +++++++++
>> >  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>> >  drivers/of/platform.c       |  5 +----
>> >  drivers/pci/probe.c         |  5 +----
>> >  include/linux/dma-mapping.h |  3 +++
>> >  5 files changed, 46 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
>> > index a1fbf55..4882f06 100644
>> > --- a/drivers/base/dd.c
>> > +++ b/drivers/base/dd.c
>> > @@ -19,6 +19,7 @@
>> >
>> >  #include <linux/device.h>
>> >  #include <linux/delay.h>
>> > +#include <linux/dma-mapping.h>
>> >  #include <linux/module.h>
>> >  #include <linux/kthread.h>
>> >  #include <linux/wait.h>
>> > @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>> >  	if (ret)
>> >  		goto pinctrl_bind_failed;
>> >
>> > +	ret = dma_configure(dev);
>> > +	if (ret)
>> > +		goto dma_failed;
>> > +
>> >  	if (driver_sysfs_add(dev)) {
>> >  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>> >  			__func__, dev_name(dev));
>> > @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>> >  	goto done;
>> >
>> >  probe_failed:
>> > +	dma_deconfigure(dev);
>> > +dma_failed:
>> >  	if (dev->bus)
>> >  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>> >  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
>> > @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>> >  			drv->remove(dev);
>> >
>> >  		device_links_driver_cleanup(dev);
>> > +		dma_deconfigure(dev);
>> > +
>> >  		devres_release_all(dev);
>> >  		dev->driver = NULL;
>> >  		dev_set_drvdata(dev, NULL);
>> > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> > index efd71cf..dfe6fd7 100644
>> > --- a/drivers/base/dma-mapping.c
>> > +++ b/drivers/base/dma-mapping.c
>> > @@ -10,6 +10,7 @@
>> >  #include <linux/dma-mapping.h>
>> >  #include <linux/export.h>
>> >  #include <linux/gfp.h>
>> > +#include <linux/of_device.h>
>> >  #include <linux/slab.h>
>> >  #include <linux/vmalloc.h>
>> >
>> > @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>> >  	vunmap(cpu_addr);
>> >  }
>> >  #endif
>> > +
>> > +/*
>> > + * Common configuration to enable DMA API use for a device
>> > + */
>> > +#include <linux/pci.h>
>> > +
>> > +int dma_configure(struct device *dev)
>> > +{
>> > +	struct device *_dev = dev;
>> > +	int is_pci = dev_is_pci(dev);
>> > +
>> > +	if (is_pci) {
>> > +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
>> > +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
>> > +		    _dev->parent->of_node)
>> > +			_dev = _dev->parent;
>> > +	}
>> > +
>> > +	if (_dev->of_node)
>> > +		of_dma_configure(dev, _dev->of_node);
>> > +
>> > +	if (is_pci)
>> > +		pci_put_host_bridge_device(_dev);
>>
>> There's a fun bug here - at this point _dev is the *parent* of the
>> bridge device, so we put the refcount on the wrong device (the platform
>> device representing the host controller, rather than the PCI device
>> representing its insides), which frees the guy we're in the middle of
>> probing, and things rapidly go wrong afterwards:
>>
>> [    1.461026] bus: 'platform': driver_probe_device: matched device
>> 40000000.pcie-controller with driver pci-host-generic
>> [    1.471640] bus: 'platform': really_probe: probing driver
>> pci-host-generic with device 40000000.pcie-controller
>> [    1.481678] OF: PCI: host bridge /pcie-controller@40000000 ranges:
>>
>> ...
>>
>> [    2.158259] bus: 'pci': driver_probe_device: matched device
>> 0000:02:10.0 with driver pcieport
>> [    2.166716] bus: 'pci': really_probe: probing driver pcieport with
>> device 0000:02:10.0
>> [    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
>> [    2.180978] pci 0000:02:10.0: Added to deferred list
>> [    2.185915] bus: 'pci': driver_probe_device: matched device
>> 0000:02:1f.0 with driver pcieport
>> [    2.194366] bus: 'pci': really_probe: probing driver pcieport with
>> device 0000:02:1f.0
>> [    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
>> [    2.208625] pci 0000:02:1f.0: Added to deferred list
>> [    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
>> '���v����.pcie-controller'
>> [    2.222293] bus: 'platform': really_probe: bound device
>> ���v����.pcie-controller to driver pci-host-generic
>> [    2.232041] Unable to handle kernel NULL pointer dereference at
>> virtual address 00000000
>>
>> I recall debugging this same issue before, and I seem to have a local
>> version of this commit dated about 6 weeks ago where dma_configure()
>> looks like this:
>>
>> --->8---
>> int dma_configure(struct device *dev)
>> {
>> 	struct device *bridge = NULL, *dma_dev = dev;
>>
>> 	if (dev_is_pci(dev)) {
>> 		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
>> 		dma_dev = bridge->parent;
>
>This would break ACPI, dma_dev would be NULL here, so from
>this standpoint (ACPI) the current patch is correct (but those [dev,_dev]
>should be renamed, they are extremely misleading so naming as
>in this hunk, which fixes DT too, is very welcome).
>

Ya, I was also thinking about the _ variable names in first place.
So i will use the names that Robin showed in his hunk and fix the 
DT case that he pointed out.

Regards,
 Sricharan

>On ACPI the DMA attributes are checked on the bridge's companion
>(ie its associated acpi_device).

[PATCH V5 05/12] drivers: platform: Configure dma operations at probe time

[Sricharan]

Hi,

>
>> > pci_bus_add_devices    (platform/amba)(_device_create/driver_register)
>> >        |                         |
>> > pci_bus_add_device     (device_add/driver_register)
>> >        |                         |
>> > device_attach           device_initial_probe
>> >        |                         |
>> > __device_attach_driver    __device_attach_driver
>> >        |
>> > driver_probe_device
>> >        |
>> > really_probe
>> >        |
>> > dma_configure
>> >
>> > Similarly on the device/driver_unregister path __device_release_driver is
>> > called which inturn calls dma_deconfigure.
>> >
>> > Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> > ---
>> >  * Removed the dma configuration for the pci devices in case of DT
>> >    from pci_dma_configure which was hanging outside separately and
>> >    doing it in dma_configure function itself.
>> >
>> >  drivers/base/dd.c           |  9 +++++++++
>> >  drivers/base/dma-mapping.c  | 32 ++++++++++++++++++++++++++++++++
>> >  drivers/of/platform.c       |  5 +----
>> >  drivers/pci/probe.c         |  5 +----
>> >  include/linux/dma-mapping.h |  3 +++
>> >  5 files changed, 46 insertions(+), 8 deletions(-)
>> >
>> > diff --git a/drivers/base/dd.c b/drivers/base/dd.c
>> > index a1fbf55..4882f06 100644
>> > --- a/drivers/base/dd.c
>> > +++ b/drivers/base/dd.c
>> > @@ -19,6 +19,7 @@
>> >
>> >  #include <linux/device.h>
>> >  #include <linux/delay.h>
>> > +#include <linux/dma-mapping.h>
>> >  #include <linux/module.h>
>> >  #include <linux/kthread.h>
>> >  #include <linux/wait.h>
>> > @@ -356,6 +357,10 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>> >  	if (ret)
>> >  		goto pinctrl_bind_failed;
>> >
>> > +	ret = dma_configure(dev);
>> > +	if (ret)
>> > +		goto dma_failed;
>> > +
>> >  	if (driver_sysfs_add(dev)) {
>> >  		printk(KERN_ERR "%s: driver_sysfs_add(%s) failed\n",
>> >  			__func__, dev_name(dev));
>> > @@ -417,6 +422,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
>> >  	goto done;
>> >
>> >  probe_failed:
>> > +	dma_deconfigure(dev);
>> > +dma_failed:
>> >  	if (dev->bus)
>> >  		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
>> >  					     BUS_NOTIFY_DRIVER_NOT_BOUND, dev);
>> > @@ -826,6 +833,8 @@ static void __device_release_driver(struct device *dev, struct device *parent)
>> >  			drv->remove(dev);
>> >
>> >  		device_links_driver_cleanup(dev);
>> > +		dma_deconfigure(dev);
>> > +
>> >  		devres_release_all(dev);
>> >  		dev->driver = NULL;
>> >  		dev_set_drvdata(dev, NULL);
>> > diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
>> > index efd71cf..dfe6fd7 100644
>> > --- a/drivers/base/dma-mapping.c
>> > +++ b/drivers/base/dma-mapping.c
>> > @@ -10,6 +10,7 @@
>> >  #include <linux/dma-mapping.h>
>> >  #include <linux/export.h>
>> >  #include <linux/gfp.h>
>> > +#include <linux/of_device.h>
>> >  #include <linux/slab.h>
>> >  #include <linux/vmalloc.h>
>> >
>> > @@ -341,3 +342,34 @@ void dma_common_free_remap(void *cpu_addr, size_t size, unsigned long vm_flags)
>> >  	vunmap(cpu_addr);
>> >  }
>> >  #endif
>> > +
>> > +/*
>> > + * Common configuration to enable DMA API use for a device
>> > + */
>> > +#include <linux/pci.h>
>> > +
>> > +int dma_configure(struct device *dev)
>> > +{
>> > +	struct device *_dev = dev;
>> > +	int is_pci = dev_is_pci(dev);
>> > +
>> > +	if (is_pci) {
>> > +		_dev = pci_get_host_bridge_device(to_pci_dev(dev));
>> > +		if (IS_ENABLED(CONFIG_OF) && _dev->parent &&
>> > +		    _dev->parent->of_node)
>> > +			_dev = _dev->parent;
>> > +	}
>> > +
>> > +	if (_dev->of_node)
>> > +		of_dma_configure(dev, _dev->of_node);
>> > +
>> > +	if (is_pci)
>> > +		pci_put_host_bridge_device(_dev);
>>
>> There's a fun bug here - at this point _dev is the *parent* of the
>> bridge device, so we put the refcount on the wrong device (the platform
>> device representing the host controller, rather than the PCI device
>> representing its insides), which frees the guy we're in the middle of
>> probing, and things rapidly go wrong afterwards:
>>
>> [    1.461026] bus: 'platform': driver_probe_device: matched device
>> 40000000.pcie-controller with driver pci-host-generic
>> [    1.471640] bus: 'platform': really_probe: probing driver
>> pci-host-generic with device 40000000.pcie-controller
>> [    1.481678] OF: PCI: host bridge /pcie-controller at 40000000 ranges:
>>
>> ...
>>
>> [    2.158259] bus: 'pci': driver_probe_device: matched device
>> 0000:02:10.0 with driver pcieport
>> [    2.166716] bus: 'pci': really_probe: probing driver pcieport with
>> device 0000:02:10.0
>> [    2.174590] pci 0000:02:10.0: Driver pcieport requests probe deferral
>> [    2.180978] pci 0000:02:10.0: Added to deferred list
>> [    2.185915] bus: 'pci': driver_probe_device: matched device
>> 0000:02:1f.0 with driver pcieport
>> [    2.194366] bus: 'pci': really_probe: probing driver pcieport with
>> device 0000:02:1f.0
>> [    2.202237] pci 0000:02:1f.0: Driver pcieport requests probe deferral
>> [    2.208625] pci 0000:02:1f.0: Added to deferred list
>> [    2.213582] driver: 'pci-host-generic': driver_bound: bound to device
>> '???v????.pcie-controller'
>> [    2.222293] bus: 'platform': really_probe: bound device
>> ???v????.pcie-controller to driver pci-host-generic
>> [    2.232041] Unable to handle kernel NULL pointer dereference at
>> virtual address 00000000
>>
>> I recall debugging this same issue before, and I seem to have a local
>> version of this commit dated about 6 weeks ago where dma_configure()
>> looks like this:
>>
>> --->8---
>> int dma_configure(struct device *dev)
>> {
>> 	struct device *bridge = NULL, *dma_dev = dev;
>>
>> 	if (dev_is_pci(dev)) {
>> 		bridge = pci_get_host_bridge_device(to_pci_dev(dev));
>> 		dma_dev = bridge->parent;
>
>This would break ACPI, dma_dev would be NULL here, so from
>this standpoint (ACPI) the current patch is correct (but those [dev,_dev]
>should be renamed, they are extremely misleading so naming as
>in this hunk, which fixes DT too, is very welcome).
>

Ya, I was also thinking about the _ variable names in first place.
So i will use the names that Robin showed in his hunk and fix the 
DT case that he pointed out.

Regards,
 Sricharan

>On ACPI the DMA attributes are checked on the bridge's companion
>(ie its associated acpi_device).

RE: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Sricharan]

Hi Robin,

>-----Original Message-----
>From: linux-arm-msm-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org [mailto:linux-arm-msm-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org] On Behalf Of Robin Murphy
>Sent: Thursday, January 19, 2017 11:28 PM
>To: Lorenzo Pieralisi <lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org>; Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>Cc: will.deacon-5wv7dgnIgG8@public.gmane.org; joro-zLv9SwRftAIdnm+yROfE0A@public.gmane.org; iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org; linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org; linux-arm-
>msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; m.szyprowski-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org 
>Subject: Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds
>
>On 19/01/17 16:50, Lorenzo Pieralisi wrote:
>> On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
>>> From: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
>>>
>>> Now that the appropriate ordering is enforced via profe-deferral of
>>> masters in core code, rip it all out and bask in the simplicity.
>>>
>>> Signed-off-by: Robin Murphy <robin.murphy-5wv7dgnIgG8@public.gmane.org>
>>> [Sricharan: Rebased on top of ACPI IORT SMMU series]
>>> Signed-off-by: Sricharan R <sricharan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
>>> ---
>>>  * No change
>>
>> Well, a tad too early on the series for ACPI, aka if we bisect the
>> series here you would break ACPI.
>>
>> Totally agree on the patch, but you should move it to the end of the
>> series.
>
>Indeed - I think a more appropriate ordering of the current patch
>numbers would be:
>
>1, 2, 3, 4, 9, 5+10 (squashed), 6, 11, 7, 8, 12
>

Ok, will repost with this order.

Regards,
 Sricharan

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Sricharan]

Hi Robin,

>-----Original Message-----
From: linux-arm-msm-owner@vger.kernel.org [mailto:linux-arm-msm-owner at vger.kernel.org] On Behalf Of Robin Murphy
>Sent: Thursday, January 19, 2017 11:28 PM
>To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>; Sricharan R <sricharan@codeaurora.org>
>Cc: will.deacon at arm.com; joro at 8bytes.org; iommu at lists.linux-foundation.org; linux-arm-kernel at lists.infradead.org; linux-arm-
>msm at vger.kernel.org; m.szyprowski at samsung.com 
>Subject: Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds
>
>On 19/01/17 16:50, Lorenzo Pieralisi wrote:
>> On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
>>> From: Robin Murphy <robin.murphy@arm.com>
>>>
>>> Now that the appropriate ordering is enforced via profe-deferral of
>>> masters in core code, rip it all out and bask in the simplicity.
>>>
>>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>>> [Sricharan: Rebased on top of ACPI IORT SMMU series]
>>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>>> ---
>>>  * No change
>>
>> Well, a tad too early on the series for ACPI, aka if we bisect the
>> series here you would break ACPI.
>>
>> Totally agree on the patch, but you should move it to the end of the
>> series.
>
>Indeed - I think a more appropriate ordering of the current patch
>numbers would be:
>
>1, 2, 3, 4, 9, 5+10 (squashed), 6, 11, 7, 8, 12
>

Ok, will repost with this order.

Regards,
 Sricharan

RE: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Sricharan]

Hi Will,

>-----Original Message-----
>From: linux-arm-msm-owner@vger.kernel.org [mailto:linux-arm-msm-owner@vger.kernel.org] On Behalf Of Will Deacon
>Sent: Thursday, January 19, 2017 9:48 PM
>To: Sricharan R <sricharan@codeaurora.org>
>Cc: robin.murphy@arm.com; joro@8bytes.org; lorenzo.pieralisi@arm.com; iommu@lists.linux-foundation.org; linux-arm-
>kernel@lists.infradead.org; linux-arm-msm@vger.kernel.org; m.szyprowski@samsung.com
>Subject: Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds
>
>On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>>
>> Now that the appropriate ordering is enforced via profe-deferral of
>> masters in core code, rip it all out and bask in the simplicity.
>>
>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>> [Sricharan: Rebased on top of ACPI IORT SMMU series]
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * No change
>>
>>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>>  2 files changed, 10 insertions(+), 94 deletions(-)
>
>Acked-by: Will Deacon <will.deacon@arm.com>
>
>I can't wait to see this series merged. What's the plan for that?

Thanks. Posted V6 with your tags and comments for V5 addressed.

Regards,
 Sricharan

[PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds

[Sricharan]

Hi Will,

>-----Original Message-----
From: linux-arm-msm-owner@vger.kernel.org [mailto:linux-arm-msm-owner at vger.kernel.org] On Behalf Of Will Deacon
>Sent: Thursday, January 19, 2017 9:48 PM
>To: Sricharan R <sricharan@codeaurora.org>
>Cc: robin.murphy at arm.com; joro at 8bytes.org; lorenzo.pieralisi at arm.com; iommu at lists.linux-foundation.org; linux-arm-
>kernel at lists.infradead.org; linux-arm-msm at vger.kernel.org; m.szyprowski at samsung.com
>Subject: Re: [PATCH V5 08/12] iommu/arm-smmu: Clean up early-probing workarounds
>
>On Thu, Jan 19, 2017 at 08:35:52PM +0530, Sricharan R wrote:
>> From: Robin Murphy <robin.murphy@arm.com>
>>
>> Now that the appropriate ordering is enforced via profe-deferral of
>> masters in core code, rip it all out and bask in the simplicity.
>>
>> Signed-off-by: Robin Murphy <robin.murphy@arm.com>
>> [Sricharan: Rebased on top of ACPI IORT SMMU series]
>> Signed-off-by: Sricharan R <sricharan@codeaurora.org>
>> ---
>>  * No change
>>
>>  drivers/iommu/arm-smmu-v3.c | 46 ++---------------------------------
>>  drivers/iommu/arm-smmu.c    | 58 +++++++--------------------------------------
>>  2 files changed, 10 insertions(+), 94 deletions(-)
>
>Acked-by: Will Deacon <will.deacon@arm.com>
>
>I can't wait to see this series merged. What's the plan for that?

Thanks. Posted V6 with your tags and comments for V5 addressed.

Regards,
 Sricharan