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* [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support
@ 2018-07-27  7:02 Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 1/4] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam
                   ` (5 more replies)
  0 siblings, 6 replies; 9+ messages in thread
From: Vivek Gautam @ 2018-07-27  7:02 UTC (permalink / raw)
  To: joro, robh+dt, rjw, robin.murphy, will.deacon, iommu, devicetree,
	linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm,
	Vivek Gautam

This series provides the support for turning on the arm-smmu's
clocks/power domains using runtime pm. This is done using
device links between smmu and client devices. The device link
framework keeps the two devices in correct order for power-cycling
across runtime PM or across system-wide PM.

With addition of a new device link flag DL_FLAG_AUTOREMOVE_SUPPLIER [8]
(available in linux-next of Rafael's linux-pm tree [9]), the device links
created between arm-smmu and its clients will be automatically purged
when arm-smmu driver unbinds from its device.

As not all implementations support clock/power gating, we are checking
for a valid 'smmu->dev's pm_domain' to conditionally enable the runtime
power management for such smmu implementations that can support it.
Otherwise, the clocks are turned to be always on in .probe until .remove.
With conditional runtime pm now, we avoid touching dev->power.lock
in fastpaths for smmu implementations that don't need to do anything
useful with pm_runtime.
This lets us to use the much-argued pm_runtime_get_sync/put_sync()
calls in map/unmap callbacks so that the clients do not have to
worry about handling any of the arm-smmu's power.

This series also adds support for Qcom's arm-smmu-v2 variant that
has different clocks and power requirements.

Previous version of this patch series is @ [2].

Tested this series on msm8996, and sdm845 after pulling in Rafael's linux-pm
linux-next[9] and Joerg's iommu next[10] branches, and related changes for
device tree, etc.

Hi Robin, Will,
I have addressed the comments for v13. If there's still a chance
can you please consider pulling this for v4.19.
Thanks.

[v14]
   * Moved arm_smmu_device_reset() from arm_smmu_pm_resume() to
     arm_smmu_runtime_resume() so that the pm_resume callback calls
     only runtime_resume to resume the device.
     This should take care of restoring the state of smmu in systems
     in which smmu lose register state on power-domain collapse.

[v13]
   Addressing Rafael's comments:
   * Added .suspend pm callback to disable the clocks in system wide suspend.
   * Added corresponding clock enable in .resume pm callback.
   * Explicitly enabling/disabling the clocks now when runtime PM is disabled.
   * device_link_add() doesn't depend on pm_runtime_enabled() as we can
     use device links across system suspend/resume too.

   Addressing Robin's comments:
   * Making device_link_add failures as non-fatal.

   * Removed IOMMU_OF_DECLARE() declaration as we don't need this after Rob's
     patch that removed all of these declarations.

[v12]
   * Use new device link's flag introduced in [8] -
     DL_FLAG_AUTOREMOVE_SUPPLIER. With this devices links are automatically
     purged when arm-smmu driver unbinds.
   * Using pm_runtime_force_suspend() instead of pm_runtime_disable() to
     avoid following warning from arm_smmu_device_remove()

     [295711.537507] ------------[ cut here ]------------
     [295711.544226] Unpreparing enabled smmu_mdp_ahb_clk
     [295711.549099] WARNING: CPU: 0 PID: 1 at ../drivers/clk/clk.c:697
                     clk_core_unprepare+0xd8/0xe0
     ...
     [295711.674073] Call trace:
     [295711.679454]  clk_core_unprepare+0xd8/0xe0
     [295711.682059]  clk_unprepare+0x28/0x40
     [295711.685964]  clk_bulk_unprepare+0x28/0x40
     [295711.689701]  arm_smmu_device_remove+0x88/0xd8
     [295711.693692]  arm_smmu_device_shutdown+0xc/0x18
     [295711.698120]  platform_drv_shutdown+0x20/0x30

[v11]
   * Some more cleanups for device link. We don't need an explicit
     delete for device link from the driver, but just set the flag
     DL_FLAG_AUTOREMOVE.
     device_link_add() API description says -
     "If the DL_FLAG_AUTOREMOVE is set, the link will be removed
     automatically when the consumer device driver unbinds."
   * Addressed the comments for 'smmu' in arm_smmu_map/unmap().
   * Dropped the patch [7] that introduced device_link_del_dev() API. 

[v10]
   * Introduce device_link_del_dev() API to delete the link between
     given consumer and supplier devices. The users of device link
     do not need to store link pointer to delete the link later.
     They can straightaway use this API by passing consumer and
     supplier devices.
   * Made corresponding changes to arm-smmu driver patch handling the
     device links.
   * Dropped the patch [6] that was adding device_link_find() API to
     device core layer. device_link_del_dev() serves the purpose to
     directly delete the link between two given devices.

[v9]
   * Removed 'rpm_supported' flag, instead checking on pm_domain
     to enable runtime pm.
   * Creating device link only when the runtime pm is enabled, as we
     don't need a device link besides managing the power dependency
     between supplier and consumer devices.
   * Introducing a patch to add device_link_find() API that finds
     and existing link between supplier and consumer devices.
     Also, made necessary change to device_link_add() to use this API.
   * arm_smmu_remove_device() now uses this device_link_find() to find
     the device link between smmu device and the master device, and then
     delete this link.
   * Dropped the destroy_domain_context() fix [5] as it was rather,
     introducing catastrophically bad problem by destroying
     'good dev's domain context.
   * Added 'Reviwed-by' tag for Tomasz's review.

[v8]
   * Major change -
     - Added a flag 'rpm_supported' which each platform that supports
       runtime pm, can enable, and we enable runtime_pm over arm-smmu
       only when this flag is set.
     - Adding the conditional pm_runtime_get/put() calls to .map, .unmap
       and .attach_dev ops.
     - Dropped the patch [3] that exported pm_runtim_get/put_suupliers(),
       and also dropped the user driver patch [4] for these APIs.

   * Clock code further cleanup
     - doing only clk_bulk_enable() and clk_bulk_disable() in runtime pm
       callbacks. We shouldn't be taking a slow path (clk_prepare/unprepare())
       from these runtime pm callbacks. Thereby, moved clk_bulk_prepare() to
       arm_smmu_device_probe(), and clk_bulk_unprepare() to
       arm_smmu_device_remove().
     - clk data filling to a common method arm_smmu_fill_clk_data() that
       fills the clock ids and number of clocks.

   * Addressed other nits and comments
     - device_link_add() error path fixed.
     - Fix for checking negative error value from pm_runtime_get_sync().
     - Documentation redo.

   * Added another patch fixing the error path in arm_smmu_attach_dev()
     to destroy allocated domain context.

[v7]
   * Addressed review comments given by Robin Murphy -
     - Added device_link_del() in .remove_device path.
     - Error path cleanup in arm_smmu_add_device().
     - Added pm_runtime_get/put_sync() in .remove path, and replaced
        pm_runtime_force_suspend() with pm_runtime_disable().
     - clk_names cleanup in arm_smmu_init_clks()
   * Added 'Reviewed-by' given by Rob H.

** Change logs for previous versions is available in last series [4].


[1] https://patchwork.kernel.org/patch/10204925/
[2] https://lore.kernel.org/patchwork/cover/964655/
[3] https://patchwork.kernel.org/patch/10204945/
[4] https://patchwork.kernel.org/patch/10204925/
[5] https://patchwork.kernel.org/patch/10254105/
[6] https://patchwork.kernel.org/patch/10277975/
[7] https://patchwork.kernel.org/patch/10281613/
[8] https://patchwork.kernel.org/patch/10491481/
[9] https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/log/?h=linux-next
[10] https://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu.git/log/?h=next


Sricharan R (3):
  iommu/arm-smmu: Add pm_runtime/sleep ops
  iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
  iommu/arm-smmu: Add the device_link between masters and smmu

Vivek Gautam (1):
  iommu/arm-smmu: Add support for qcom,smmu-v2 variant

 .../devicetree/bindings/iommu/arm,smmu.txt         |  42 +++++
 drivers/iommu/arm-smmu.c                           | 194 +++++++++++++++++++--
 2 files changed, 225 insertions(+), 11 deletions(-)

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


^ permalink raw reply	[flat|nested] 9+ messages in thread

* [PATCH v14 1/4] iommu/arm-smmu: Add pm_runtime/sleep ops
  2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
@ 2018-07-27  7:02 ` Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 2/4] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 9+ messages in thread
From: Vivek Gautam @ 2018-07-27  7:02 UTC (permalink / raw)
  To: joro, robh+dt, rjw, robin.murphy, will.deacon, iommu, devicetree,
	linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm,
	Vivek Gautam

From: Sricharan R <sricharan@codeaurora.org>

The smmu needs to be functional only when the respective
master's using it are active. The device_link feature
helps to track such functional dependencies, so that the
iommu gets powered when the master device enables itself
using pm_runtime. So by adapting the smmu driver for
runtime pm, above said dependency can be addressed.

This patch adds the pm runtime/sleep callbacks to the
driver and also the functions to parse the smmu clocks
from DT and enable them in resume/suspend.

Also, while we enable the runtime pm add a pm sleep suspend
callback that pushes devices to low power state by turning
the clocks off in a system sleep.
Also add corresponding clock enable path in resume callback.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
[vivek: rework for clock and pm ops]
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
---

Changes since v13:
 - Moved arm_smmu_device_reset() from arm_smmu_pm_resume() to
   arm_smmu_runtime_resume(). arm_smmu_pm_resume() calls just
   runtime_resume() now.

 drivers/iommu/arm-smmu.c | 77 ++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 74 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index c73cfce1ccc0..5f6a9e3c0079 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -48,6 +48,7 @@
 #include <linux/of_iommu.h>
 #include <linux/pci.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 
@@ -205,6 +206,8 @@ struct arm_smmu_device {
 	u32				num_global_irqs;
 	u32				num_context_irqs;
 	unsigned int			*irqs;
+	struct clk_bulk_data		*clks;
+	int				num_clks;
 
 	u32				cavium_id_base; /* Specific to Cavium */
 
@@ -1897,10 +1900,12 @@ static int arm_smmu_device_cfg_probe(struct arm_smmu_device *smmu)
 struct arm_smmu_match_data {
 	enum arm_smmu_arch_version version;
 	enum arm_smmu_implementation model;
+	const char * const *clks;
+	int num_clks;
 };
 
 #define ARM_SMMU_MATCH_DATA(name, ver, imp)	\
-static struct arm_smmu_match_data name = { .version = ver, .model = imp }
+static const struct arm_smmu_match_data name = { .version = ver, .model = imp }
 
 ARM_SMMU_MATCH_DATA(smmu_generic_v1, ARM_SMMU_V1, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(smmu_generic_v2, ARM_SMMU_V2, GENERIC_SMMU);
@@ -1919,6 +1924,23 @@ static const struct of_device_id arm_smmu_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
 
+static void arm_smmu_fill_clk_data(struct arm_smmu_device *smmu,
+				   const char * const *clks)
+{
+	int i;
+
+	if (smmu->num_clks < 1)
+		return;
+
+	smmu->clks = devm_kcalloc(smmu->dev, smmu->num_clks,
+				  sizeof(*smmu->clks), GFP_KERNEL);
+	if (!smmu->clks)
+		return;
+
+	for (i = 0; i < smmu->num_clks; i++)
+		smmu->clks[i].id = clks[i];
+}
+
 #ifdef CONFIG_ACPI
 static int acpi_smmu_get_data(u32 model, struct arm_smmu_device *smmu)
 {
@@ -2001,6 +2023,9 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
 	data = of_device_get_match_data(dev);
 	smmu->version = data->version;
 	smmu->model = data->model;
+	smmu->num_clks = data->num_clks;
+
+	arm_smmu_fill_clk_data(smmu, data->clks);
 
 	parse_driver_options(smmu);
 
@@ -2099,6 +2124,14 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 		smmu->irqs[i] = irq;
 	}
 
+	err = devm_clk_bulk_get(smmu->dev, smmu->num_clks, smmu->clks);
+	if (err)
+		return err;
+
+	err = clk_bulk_prepare(smmu->num_clks, smmu->clks);
+	if (err)
+		return err;
+
 	err = arm_smmu_device_cfg_probe(smmu);
 	if (err)
 		return err;
@@ -2181,6 +2214,9 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 
 	/* Turn the thing off */
 	writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
+
+	clk_bulk_unprepare(smmu->num_clks, smmu->clks);
+
 	return 0;
 }
 
@@ -2189,15 +2225,50 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev)
 	arm_smmu_device_remove(pdev);
 }
 
-static int __maybe_unused arm_smmu_pm_resume(struct device *dev)
+static int __maybe_unused arm_smmu_runtime_resume(struct device *dev)
 {
 	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_bulk_enable(smmu->num_clks, smmu->clks);
+	if (ret)
+		return ret;
 
 	arm_smmu_device_reset(smmu);
+
 	return 0;
 }
 
-static SIMPLE_DEV_PM_OPS(arm_smmu_pm_ops, NULL, arm_smmu_pm_resume);
+static int __maybe_unused arm_smmu_runtime_suspend(struct device *dev)
+{
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+	clk_bulk_disable(smmu->num_clks, smmu->clks);
+
+	return 0;
+}
+
+static int __maybe_unused arm_smmu_pm_resume(struct device *dev)
+{
+	if (pm_runtime_suspended(dev))
+		return 0;
+
+	return arm_smmu_runtime_resume(dev);
+}
+
+static int __maybe_unused arm_smmu_pm_suspend(struct device *dev)
+{
+	if (pm_runtime_suspended(dev))
+		return 0;
+
+	return arm_smmu_runtime_suspend(dev);
+}
+
+static const struct dev_pm_ops arm_smmu_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(arm_smmu_pm_suspend, arm_smmu_pm_resume)
+	SET_RUNTIME_PM_OPS(arm_smmu_runtime_suspend,
+			   arm_smmu_runtime_resume, NULL)
+};
 
 static struct platform_driver arm_smmu_driver = {
 	.driver	= {
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v14 2/4] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
  2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 1/4] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam
@ 2018-07-27  7:02 ` Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 3/4] iommu/arm-smmu: Add the device_link between masters and smmu Vivek Gautam
                   ` (3 subsequent siblings)
  5 siblings, 0 replies; 9+ messages in thread
From: Vivek Gautam @ 2018-07-27  7:02 UTC (permalink / raw)
  To: joro, robh+dt, rjw, robin.murphy, will.deacon, iommu, devicetree,
	linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm,
	Vivek Gautam

From: Sricharan R <sricharan@codeaurora.org>

The smmu device probe/remove and add/remove master device callbacks
gets called when the smmu is not linked to its master, that is without
the context of the master device. So calling runtime apis in those places
separately.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
[vivek: Cleanup pm runtime calls]
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
---

Change since v13:
 - No change.

 drivers/iommu/arm-smmu.c | 101 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 93 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 5f6a9e3c0079..1efa5681b905 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -268,6 +268,20 @@ static struct arm_smmu_option_prop arm_smmu_options[] = {
 	{ 0, NULL},
 };
 
+static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu)
+{
+	if (pm_runtime_enabled(smmu->dev))
+		return pm_runtime_get_sync(smmu->dev);
+
+	return 0;
+}
+
+static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu)
+{
+	if (pm_runtime_enabled(smmu->dev))
+		pm_runtime_put(smmu->dev);
+}
+
 static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 {
 	return container_of(dom, struct arm_smmu_domain, domain);
@@ -913,11 +927,15 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
-	int irq;
+	int ret, irq;
 
 	if (!smmu || domain->type == IOMMU_DOMAIN_IDENTITY)
 		return;
 
+	ret = arm_smmu_rpm_get(smmu);
+	if (ret < 0)
+		return;
+
 	/*
 	 * Disable the context bank and free the page tables before freeing
 	 * it.
@@ -932,6 +950,8 @@ static void arm_smmu_destroy_domain_context(struct iommu_domain *domain)
 
 	free_io_pgtable_ops(smmu_domain->pgtbl_ops);
 	__arm_smmu_free_bitmap(smmu->context_map, cfg->cbndx);
+
+	arm_smmu_rpm_put(smmu);
 }
 
 static struct iommu_domain *arm_smmu_domain_alloc(unsigned type)
@@ -1213,10 +1233,15 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		return -ENODEV;
 
 	smmu = fwspec_smmu(fwspec);
+
+	ret = arm_smmu_rpm_get(smmu);
+	if (ret < 0)
+		return ret;
+
 	/* Ensure that the domain is finalised */
 	ret = arm_smmu_init_domain_context(domain, smmu);
 	if (ret < 0)
-		return ret;
+		goto rpm_put;
 
 	/*
 	 * Sanity check the domain. We don't support domains across
@@ -1226,33 +1251,50 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
 		dev_err(dev,
 			"cannot attach to SMMU %s whilst already attached to domain on SMMU %s\n",
 			dev_name(smmu_domain->smmu->dev), dev_name(smmu->dev));
-		return -EINVAL;
+		ret = -EINVAL;
+		goto rpm_put;
 	}
 
 	/* Looks ok, so add the device to the domain */
-	return arm_smmu_domain_add_master(smmu_domain, fwspec);
+	ret = arm_smmu_domain_add_master(smmu_domain, fwspec);
+
+rpm_put:
+	arm_smmu_rpm_put(smmu);
+	return ret;
 }
 
 static int arm_smmu_map(struct iommu_domain *domain, unsigned long iova,
 			phys_addr_t paddr, size_t size, int prot)
 {
 	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
+	struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu;
+	int ret;
 
 	if (!ops)
 		return -ENODEV;
 
-	return ops->map(ops, iova, paddr, size, prot);
+	arm_smmu_rpm_get(smmu);
+	ret = ops->map(ops, iova, paddr, size, prot);
+	arm_smmu_rpm_put(smmu);
+
+	return ret;
 }
 
 static size_t arm_smmu_unmap(struct iommu_domain *domain, unsigned long iova,
 			     size_t size)
 {
 	struct io_pgtable_ops *ops = to_smmu_domain(domain)->pgtbl_ops;
+	struct arm_smmu_device *smmu = to_smmu_domain(domain)->smmu;
+	size_t ret;
 
 	if (!ops)
 		return 0;
 
-	return ops->unmap(ops, iova, size);
+	arm_smmu_rpm_get(smmu);
+	ret = ops->unmap(ops, iova, size);
+	arm_smmu_rpm_put(smmu);
+
+	return ret;
 }
 
 static void arm_smmu_iotlb_sync(struct iommu_domain *domain)
@@ -1407,7 +1449,13 @@ static int arm_smmu_add_device(struct device *dev)
 	while (i--)
 		cfg->smendx[i] = INVALID_SMENDX;
 
+	ret = arm_smmu_rpm_get(smmu);
+	if (ret < 0)
+		goto out_cfg_free;
+
 	ret = arm_smmu_master_alloc_smes(dev);
+	arm_smmu_rpm_put(smmu);
+
 	if (ret)
 		goto out_cfg_free;
 
@@ -1427,7 +1475,7 @@ static void arm_smmu_remove_device(struct device *dev)
 	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
 	struct arm_smmu_master_cfg *cfg;
 	struct arm_smmu_device *smmu;
-
+	int ret;
 
 	if (!fwspec || fwspec->ops != &arm_smmu_ops)
 		return;
@@ -1435,8 +1483,15 @@ static void arm_smmu_remove_device(struct device *dev)
 	cfg  = fwspec->iommu_priv;
 	smmu = cfg->smmu;
 
+	ret = arm_smmu_rpm_get(smmu);
+	if (ret < 0)
+		return;
+
 	iommu_device_unlink(&smmu->iommu, dev);
 	arm_smmu_master_free_smes(fwspec);
+
+	arm_smmu_rpm_put(smmu);
+
 	iommu_group_remove_device(dev);
 	kfree(fwspec->iommu_priv);
 	iommu_fwspec_free(dev);
@@ -2124,6 +2179,8 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 		smmu->irqs[i] = irq;
 	}
 
+	platform_set_drvdata(pdev, smmu);
+
 	err = devm_clk_bulk_get(smmu->dev, smmu->num_clks, smmu->clks);
 	if (err)
 		return err;
@@ -2132,6 +2189,26 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	if (err)
 		return err;
 
+	/*
+	 * We want to avoid touching dev->power.lock in fastpaths unless
+	 * it's really going to do something useful - pm_runtime_enabled()
+	 * can serve as an ideal proxy for that decision. So, conditionally
+	 * enable pm_runtime.
+	 */
+	if (dev->pm_domain)
+		pm_runtime_enable(dev);
+
+	err = arm_smmu_rpm_get(smmu);
+	if (err < 0)
+		return err;
+
+	/* Enable clocks explicitly if runtime PM is disabled */
+	if (!pm_runtime_enabled(dev)) {
+		err = clk_bulk_enable(smmu->num_clks, smmu->clks);
+		if (err)
+			return err;
+	}
+
 	err = arm_smmu_device_cfg_probe(smmu);
 	if (err)
 		return err;
@@ -2173,10 +2250,11 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 		return err;
 	}
 
-	platform_set_drvdata(pdev, smmu);
 	arm_smmu_device_reset(smmu);
 	arm_smmu_test_smr_masks(smmu);
 
+	arm_smmu_rpm_put(smmu);
+
 	/*
 	 * For ACPI and generic DT bindings, an SMMU will be probed before
 	 * any device which might need it, so we want the bus ops in place
@@ -2212,8 +2290,15 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
 	if (!bitmap_empty(smmu->context_map, ARM_SMMU_MAX_CBS))
 		dev_err(&pdev->dev, "removing device with active domains!\n");
 
+	arm_smmu_rpm_get(smmu);
 	/* Turn the thing off */
 	writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0);
+	arm_smmu_rpm_put(smmu);
+
+	if (pm_runtime_enabled(smmu->dev))
+		pm_runtime_force_suspend(smmu->dev);
+	else
+		clk_bulk_disable(smmu->num_clks, smmu->clks);
 
 	clk_bulk_unprepare(smmu->num_clks, smmu->clks);
 
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v14 3/4] iommu/arm-smmu: Add the device_link between masters and smmu
  2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 1/4] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 2/4] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam
@ 2018-07-27  7:02 ` Vivek Gautam
  2018-07-27  7:02 ` [PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant Vivek Gautam
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 9+ messages in thread
From: Vivek Gautam @ 2018-07-27  7:02 UTC (permalink / raw)
  To: joro, robh+dt, rjw, robin.murphy, will.deacon, iommu, devicetree,
	linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm,
	Vivek Gautam

From: Sricharan R <sricharan@codeaurora.org>

Finally add the device link between the master device and
smmu, so that the smmu gets runtime enabled/disabled only when the
master needs it. This is done from add_device callback which gets
called once when the master is added to the smmu.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
---

Change since v13:
 - No change.

 drivers/iommu/arm-smmu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 1efa5681b905..e558abf1ecfc 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1461,6 +1461,9 @@ static int arm_smmu_add_device(struct device *dev)
 
 	iommu_device_link(&smmu->iommu, dev);
 
+	device_link_add(dev, smmu->dev,
+			DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER);
+
 	return 0;
 
 out_cfg_free:
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* [PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant
  2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
                   ` (2 preceding siblings ...)
  2018-07-27  7:02 ` [PATCH v14 3/4] iommu/arm-smmu: Add the device_link between masters and smmu Vivek Gautam
@ 2018-07-27  7:02 ` Vivek Gautam
  2018-08-22 15:27   ` Robin Murphy
  2018-08-20  9:31 ` [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Tomasz Figa
  2018-08-21 13:03 ` Srinivas Kandagatla
  5 siblings, 1 reply; 9+ messages in thread
From: Vivek Gautam @ 2018-07-27  7:02 UTC (permalink / raw)
  To: joro, robh+dt, rjw, robin.murphy, will.deacon, iommu, devicetree,
	linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm,
	Vivek Gautam

qcom,smmu-v2 is an arm,smmu-v2 implementation with specific
clock and power requirements. This smmu core is used with
multiple masters on msm8996, viz. mdss, video, etc.
Add bindings for the same.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
---

Change since v13:
 - No change.

 .../devicetree/bindings/iommu/arm,smmu.txt         | 42 ++++++++++++++++++++++
 drivers/iommu/arm-smmu.c                           | 13 +++++++
 2 files changed, 55 insertions(+)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 8a6ffce12af5..7c71a6ed465a 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -17,10 +17,19 @@ conditions.
                         "arm,mmu-401"
                         "arm,mmu-500"
                         "cavium,smmu-v2"
+                        "qcom,<soc>-smmu-v2", "qcom,smmu-v2"
 
                   depending on the particular implementation and/or the
                   version of the architecture implemented.
 
+                  A number of Qcom SoCs use qcom,smmu-v2 version of the IP.
+                  "qcom,<soc>-smmu-v2" represents a soc specific compatible
+                  string that should be present along with the "qcom,smmu-v2"
+                  to facilitate SoC specific clocks/power connections and to
+                  address specific bug fixes.
+                  An example string would be -
+                  "qcom,msm8996-smmu-v2", "qcom,smmu-v2".
+
 - reg           : Base address and size of the SMMU.
 
 - #global-interrupts : The number of global interrupts exposed by the
@@ -71,6 +80,22 @@ conditions.
                   or using stream matching with #iommu-cells = <2>, and
                   may be ignored if present in such cases.
 
+- clock-names:    List of the names of clocks input to the device. The
+                  required list depends on particular implementation and
+                  is as follows:
+                  - for "qcom,smmu-v2":
+                    - "bus": clock required for downstream bus access and
+                             for the smmu ptw,
+                    - "iface": clock required to access smmu's registers
+                               through the TCU's programming interface.
+                  - unspecified for other implementations.
+
+- clocks:         Specifiers for all clocks listed in the clock-names property,
+                  as per generic clock bindings.
+
+- power-domains:  Specifiers for power domains required to be powered on for
+                  the SMMU to operate, as per generic power domain bindings.
+
 ** Deprecated properties:
 
 - mmu-masters (deprecated in favour of the generic "iommus" binding) :
@@ -137,3 +162,20 @@ conditions.
                 iommu-map = <0 &smmu3 0 0x400>;
                 ...
         };
+
+	/* Qcom's arm,smmu-v2 implementation */
+	smmu4: iommu {
+		compatible = "qcom,msm8996-smmu-v2", "qcom,smmu-v2";
+		reg = <0xd00000 0x10000>;
+
+		#global-interrupts = <1>;
+		interrupts = <GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 320 IRQ_TYPE_LEVEL_HIGH>,
+			     <GIC_SPI 321 IRQ_TYPE_LEVEL_HIGH>;
+		#iommu-cells = <1>;
+		power-domains = <&mmcc MDSS_GDSC>;
+
+		clocks = <&mmcc SMMU_MDP_AXI_CLK>,
+			 <&mmcc SMMU_MDP_AHB_CLK>;
+		clock-names = "bus", "iface";
+	};
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index e558abf1ecfc..2b4edba188a5 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -119,6 +119,7 @@ enum arm_smmu_implementation {
 	GENERIC_SMMU,
 	ARM_MMU500,
 	CAVIUM_SMMUV2,
+	QCOM_SMMUV2,
 };
 
 struct arm_smmu_s2cr {
@@ -1971,6 +1972,17 @@ ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU);
 ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500);
 ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2);
 
+static const char * const qcom_smmuv2_clks[] = {
+	"bus", "iface",
+};
+
+static const struct arm_smmu_match_data qcom_smmuv2 = {
+	.version = ARM_SMMU_V2,
+	.model = QCOM_SMMUV2,
+	.clks = qcom_smmuv2_clks,
+	.num_clks = ARRAY_SIZE(qcom_smmuv2_clks),
+};
+
 static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,smmu-v1", .data = &smmu_generic_v1 },
 	{ .compatible = "arm,smmu-v2", .data = &smmu_generic_v2 },
@@ -1978,6 +1990,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,mmu-401", .data = &arm_mmu401 },
 	{ .compatible = "arm,mmu-500", .data = &arm_mmu500 },
 	{ .compatible = "cavium,smmu-v2", .data = &cavium_smmuv2 },
+	{ .compatible = "qcom,smmu-v2", .data = &qcom_smmuv2 },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
of Code Aurora Forum, hosted by The Linux Foundation


^ permalink raw reply related	[flat|nested] 9+ messages in thread

* Re: [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support
  2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
                   ` (3 preceding siblings ...)
  2018-07-27  7:02 ` [PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant Vivek Gautam
@ 2018-08-20  9:31 ` Tomasz Figa
  2018-08-22 15:43   ` Robin Murphy
  2018-08-21 13:03 ` Srinivas Kandagatla
  5 siblings, 1 reply; 9+ messages in thread
From: Tomasz Figa @ 2018-08-20  9:31 UTC (permalink / raw)
  To: Robin Murphy
  Cc: list@263.net:IOMMU DRIVERS
	<iommu@lists.linux-foundation.org>,
	Joerg Roedel <joro@8bytes.org>,,
	Rob Herring, Vivek Gautam, Rafael J. Wysocki, Will Deacon,
	list@263.net:IOMMU DRIVERS
	<iommu@lists.linux-foundation.org>,
	Joerg Roedel <joro@8bytes.org>,,
	devicetree, Linux Kernel Mailing List, freedreno,
	Alex Williamson, Mark Rutland, Rob Clark, Linux PM, sboyd,
	jcrouse, Sricharan R, Marek Szyprowski, Archit Taneja,
	linux-arm-msm

Hi Robin,

On Fri, Jul 27, 2018 at 4:02 PM Vivek Gautam
<vivek.gautam@codeaurora.org> wrote:
>
> This series provides the support for turning on the arm-smmu's
> clocks/power domains using runtime pm. This is done using
> device links between smmu and client devices. The device link
> framework keeps the two devices in correct order for power-cycling
> across runtime PM or across system-wide PM.
>
> With addition of a new device link flag DL_FLAG_AUTOREMOVE_SUPPLIER [8]
> (available in linux-next of Rafael's linux-pm tree [9]), the device links
> created between arm-smmu and its clients will be automatically purged
> when arm-smmu driver unbinds from its device.
>
> As not all implementations support clock/power gating, we are checking
> for a valid 'smmu->dev's pm_domain' to conditionally enable the runtime
> power management for such smmu implementations that can support it.
> Otherwise, the clocks are turned to be always on in .probe until .remove.
> With conditional runtime pm now, we avoid touching dev->power.lock
> in fastpaths for smmu implementations that don't need to do anything
> useful with pm_runtime.
> This lets us to use the much-argued pm_runtime_get_sync/put_sync()
> calls in map/unmap callbacks so that the clients do not have to
> worry about handling any of the arm-smmu's power.
>
> This series also adds support for Qcom's arm-smmu-v2 variant that
> has different clocks and power requirements.
>
> Previous version of this patch series is @ [2].
>
> Tested this series on msm8996, and sdm845 after pulling in Rafael's linux-pm
> linux-next[9] and Joerg's iommu next[10] branches, and related changes for
> device tree, etc.
>
> Hi Robin, Will,
> I have addressed the comments for v13. If there's still a chance
> can you please consider pulling this for v4.19.
> Thanks.
>
> [v14]
>    * Moved arm_smmu_device_reset() from arm_smmu_pm_resume() to
>      arm_smmu_runtime_resume() so that the pm_resume callback calls
>      only runtime_resume to resume the device.
>      This should take care of restoring the state of smmu in systems
>      in which smmu lose register state on power-domain collapse.

It's been a while since this series was posted and no more comments
seem to be left anymore. Would you have some time to take a look
again? Thanks.

Best regards,
Tomasz

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support
  2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
                   ` (4 preceding siblings ...)
  2018-08-20  9:31 ` [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Tomasz Figa
@ 2018-08-21 13:03 ` Srinivas Kandagatla
  5 siblings, 0 replies; 9+ messages in thread
From: Srinivas Kandagatla @ 2018-08-21 13:03 UTC (permalink / raw)
  To: Vivek Gautam, joro, robh+dt, rjw, robin.murphy, will.deacon,
	iommu, devicetree, linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm



On 27/07/18 08:02, Vivek Gautam wrote:
> Sricharan R (3):
>    iommu/arm-smmu: Add pm_runtime/sleep ops
>    iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device
>    iommu/arm-smmu: Add the device_link between masters and smmu
> 
> Vivek Gautam (1):
>    iommu/arm-smmu: Add support for qcom,smmu-v2 variant
> 
>   .../devicetree/bindings/iommu/arm,smmu.txt         |  42 +++++
>   drivers/iommu/arm-smmu.c                           | 194 +++++++++++++++++++--
>   2 files changed, 225 insertions(+), 11 deletions(-)
MSM8896 audio and display on top of mainline totally depends on this 
patches, I have been testing various version this series on DB820c for 
both display and audio.

Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>


--srini

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant
  2018-07-27  7:02 ` [PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant Vivek Gautam
@ 2018-08-22 15:27   ` Robin Murphy
  0 siblings, 0 replies; 9+ messages in thread
From: Robin Murphy @ 2018-08-22 15:27 UTC (permalink / raw)
  To: Vivek Gautam, joro, robh+dt, rjw, will.deacon, iommu, devicetree,
	linux-kernel, freedreno
  Cc: alex.williamson, mark.rutland, robdclark, linux-pm, sboyd, tfiga,
	jcrouse, sricharan, m.szyprowski, architt, linux-arm-msm

On 27/07/18 08:02, Vivek Gautam wrote:
> qcom,smmu-v2 is an arm,smmu-v2 implementation with specific
> clock and power requirements. This smmu core is used with
> multiple masters on msm8996, viz. mdss, video, etc.
> Add bindings for the same.
> 
> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
> Reviewed-by: Rob Herring <robh@kernel.org>
> Reviewed-by: Tomasz Figa <tfiga@chromium.org>
> ---
> 
> Change since v13:
>   - No change.
> 
>   .../devicetree/bindings/iommu/arm,smmu.txt         | 42 ++++++++++++++++++++++
>   drivers/iommu/arm-smmu.c                           | 13 +++++++
>   2 files changed, 55 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
> index 8a6ffce12af5..7c71a6ed465a 100644
> --- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
> @@ -17,10 +17,19 @@ conditions.
>                           "arm,mmu-401"
>                           "arm,mmu-500"
>                           "cavium,smmu-v2"
> +                        "qcom,<soc>-smmu-v2", "qcom,smmu-v2"
>   
>                     depending on the particular implementation and/or the
>                     version of the architecture implemented.
>   
> +                  A number of Qcom SoCs use qcom,smmu-v2 version of the IP.
> +                  "qcom,<soc>-smmu-v2" represents a soc specific compatible
> +                  string that should be present along with the "qcom,smmu-v2"
> +                  to facilitate SoC specific clocks/power connections and to
> +                  address specific bug fixes.

As demonstrated in the GPU thread, this proves a bit too vague for a 
useful binding. Provided Qcom folks can reach a consensus on what a 
given SoC is actually called, I'd rather just unambiguously list 
whatever sets of fully-defined strings we need.

Robin.

> +                  An example string would be -
> +                  "qcom,msm8996-smmu-v2", "qcom,smmu-v2".
> +
>   - reg           : Base address and size of the SMMU.
>   
>   - #global-interrupts : The number of global interrupts exposed by the
> @@ -71,6 +80,22 @@ conditions.
>                     or using stream matching with #iommu-cells = <2>, and
>                     may be ignored if present in such cases.
>   
> +- clock-names:    List of the names of clocks input to the device. The
> +                  required list depends on particular implementation and
> +                  is as follows:
> +                  - for "qcom,smmu-v2":
> +                    - "bus": clock required for downstream bus access and
> +                             for the smmu ptw,
> +                    - "iface": clock required to access smmu's registers
> +                               through the TCU's programming interface.
> +                  - unspecified for other implementations.
> +
> +- clocks:         Specifiers for all clocks listed in the clock-names property,
> +                  as per generic clock bindings.
> +
> +- power-domains:  Specifiers for power domains required to be powered on for
> +                  the SMMU to operate, as per generic power domain bindings.
> +
>   ** Deprecated properties:
>   
>   - mmu-masters (deprecated in favour of the generic "iommus" binding) :
> @@ -137,3 +162,20 @@ conditions.
>                   iommu-map = <0 &smmu3 0 0x400>;
>                   ...
>           };
> +
> +	/* Qcom's arm,smmu-v2 implementation */
> +	smmu4: iommu {
> +		compatible = "qcom,msm8996-smmu-v2", "qcom,smmu-v2";
> +		reg = <0xd00000 0x10000>;
> +
> +		#global-interrupts = <1>;
> +		interrupts = <GIC_SPI 73 IRQ_TYPE_LEVEL_HIGH>,
> +			     <GIC_SPI 320 IRQ_TYPE_LEVEL_HIGH>,
> +			     <GIC_SPI 321 IRQ_TYPE_LEVEL_HIGH>;
> +		#iommu-cells = <1>;
> +		power-domains = <&mmcc MDSS_GDSC>;
> +
> +		clocks = <&mmcc SMMU_MDP_AXI_CLK>,
> +			 <&mmcc SMMU_MDP_AHB_CLK>;
> +		clock-names = "bus", "iface";
> +	};
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index e558abf1ecfc..2b4edba188a5 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -119,6 +119,7 @@ enum arm_smmu_implementation {
>   	GENERIC_SMMU,
>   	ARM_MMU500,
>   	CAVIUM_SMMUV2,
> +	QCOM_SMMUV2,
>   };
>   
>   struct arm_smmu_s2cr {
> @@ -1971,6 +1972,17 @@ ARM_SMMU_MATCH_DATA(arm_mmu401, ARM_SMMU_V1_64K, GENERIC_SMMU);
>   ARM_SMMU_MATCH_DATA(arm_mmu500, ARM_SMMU_V2, ARM_MMU500);
>   ARM_SMMU_MATCH_DATA(cavium_smmuv2, ARM_SMMU_V2, CAVIUM_SMMUV2);
>   
> +static const char * const qcom_smmuv2_clks[] = {
> +	"bus", "iface",
> +};
> +
> +static const struct arm_smmu_match_data qcom_smmuv2 = {
> +	.version = ARM_SMMU_V2,
> +	.model = QCOM_SMMUV2,
> +	.clks = qcom_smmuv2_clks,
> +	.num_clks = ARRAY_SIZE(qcom_smmuv2_clks),
> +};
> +
>   static const struct of_device_id arm_smmu_of_match[] = {
>   	{ .compatible = "arm,smmu-v1", .data = &smmu_generic_v1 },
>   	{ .compatible = "arm,smmu-v2", .data = &smmu_generic_v2 },
> @@ -1978,6 +1990,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
>   	{ .compatible = "arm,mmu-401", .data = &arm_mmu401 },
>   	{ .compatible = "arm,mmu-500", .data = &arm_mmu500 },
>   	{ .compatible = "cavium,smmu-v2", .data = &cavium_smmuv2 },
> +	{ .compatible = "qcom,smmu-v2", .data = &qcom_smmuv2 },
>   	{ },
>   };
>   MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
> 

^ permalink raw reply	[flat|nested] 9+ messages in thread

* Re: [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support
  2018-08-20  9:31 ` [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Tomasz Figa
@ 2018-08-22 15:43   ` Robin Murphy
  0 siblings, 0 replies; 9+ messages in thread
From: Robin Murphy @ 2018-08-22 15:43 UTC (permalink / raw)
  To: Tomasz Figa
  Cc: list@263.net:IOMMU DRIVERS, Joerg Roedel, joro, Rob Herring,
	Vivek Gautam, Rafael J. Wysocki, Will Deacon,
	list@263.net:IOMMU DRIVERS, Joerg Roedel, iommu, devicetree,
	Linux Kernel Mailing List, freedreno, Alex Williamson,
	Mark Rutland, Rob Clark, Linux PM, sboyd, jcrouse, Sricharan R,
	Marek Szyprowski, Archit Taneja, linux-arm-msm

On 20/08/18 10:31, Tomasz Figa wrote:
> Hi Robin,
> 
> On Fri, Jul 27, 2018 at 4:02 PM Vivek Gautam
> <vivek.gautam@codeaurora.org> wrote:
>>
>> This series provides the support for turning on the arm-smmu's
>> clocks/power domains using runtime pm. This is done using
>> device links between smmu and client devices. The device link
>> framework keeps the two devices in correct order for power-cycling
>> across runtime PM or across system-wide PM.
>>
>> With addition of a new device link flag DL_FLAG_AUTOREMOVE_SUPPLIER [8]
>> (available in linux-next of Rafael's linux-pm tree [9]), the device links
>> created between arm-smmu and its clients will be automatically purged
>> when arm-smmu driver unbinds from its device.
>>
>> As not all implementations support clock/power gating, we are checking
>> for a valid 'smmu->dev's pm_domain' to conditionally enable the runtime
>> power management for such smmu implementations that can support it.
>> Otherwise, the clocks are turned to be always on in .probe until .remove.
>> With conditional runtime pm now, we avoid touching dev->power.lock
>> in fastpaths for smmu implementations that don't need to do anything
>> useful with pm_runtime.
>> This lets us to use the much-argued pm_runtime_get_sync/put_sync()
>> calls in map/unmap callbacks so that the clients do not have to
>> worry about handling any of the arm-smmu's power.
>>
>> This series also adds support for Qcom's arm-smmu-v2 variant that
>> has different clocks and power requirements.
>>
>> Previous version of this patch series is @ [2].
>>
>> Tested this series on msm8996, and sdm845 after pulling in Rafael's linux-pm
>> linux-next[9] and Joerg's iommu next[10] branches, and related changes for
>> device tree, etc.
>>
>> Hi Robin, Will,
>> I have addressed the comments for v13. If there's still a chance
>> can you please consider pulling this for v4.19.
>> Thanks.
>>
>> [v14]
>>     * Moved arm_smmu_device_reset() from arm_smmu_pm_resume() to
>>       arm_smmu_runtime_resume() so that the pm_resume callback calls
>>       only runtime_resume to resume the device.
>>       This should take care of restoring the state of smmu in systems
>>       in which smmu lose register state on power-domain collapse.
> 
> It's been a while since this series was posted and no more comments
> seem to be left anymore. Would you have some time to take a look
> again? Thanks.

Other than the binding issue which turned up in the meantime, I *think* 
this is looking OK now in terms of being sufficiently safe for all the 
various awkward retention vs. state-loss combinations. There's almost 
certainly still ways to improve it in future, but what we have now seems 
like a reasonable starting point that isn't impossibly complicated to 
reason about.

Robin.

^ permalink raw reply	[flat|nested] 9+ messages in thread

end of thread, other threads:[~2018-08-22 15:43 UTC | newest]

Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-07-27  7:02 [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Vivek Gautam
2018-07-27  7:02 ` [PATCH v14 1/4] iommu/arm-smmu: Add pm_runtime/sleep ops Vivek Gautam
2018-07-27  7:02 ` [PATCH v14 2/4] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device Vivek Gautam
2018-07-27  7:02 ` [PATCH v14 3/4] iommu/arm-smmu: Add the device_link between masters and smmu Vivek Gautam
2018-07-27  7:02 ` [PATCH v14 4/4] iommu/arm-smmu: Add support for qcom,smmu-v2 variant Vivek Gautam
2018-08-22 15:27   ` Robin Murphy
2018-08-20  9:31 ` [PATCH v14 0/4] iommu/arm-smmu: Add runtime pm/sleep support Tomasz Figa
2018-08-22 15:43   ` Robin Murphy
2018-08-21 13:03 ` Srinivas Kandagatla

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