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* [PATCH v15 0/9] PCI: Expose and manage PCI device reset
@ 2021-08-05 16:29 Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 1/9] PCI: Cache PCIe FLR capability Amey Narkhede
                   ` (9 more replies)
  0 siblings, 10 replies; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

PCI and PCIe devices may support a number of possible reset mechanisms
for example Function Level Reset (FLR) provided via Advanced Feature or
PCIe capabilities, Power Management reset, bus reset, or device specific reset.
Currently the PCI subsystem creates a policy prioritizing these reset methods
which provides neither visibility nor control to userspace.

Expose the reset methods available per device to userspace, via sysfs
and allow an administrative user or device owner to have ability to
manage per device reset method priorities or exclusions.
This feature aims to allow greater control of a device for use cases
as device assignment, where specific device or platform issues may
interact poorly with a given reset method, and for which device specific
quirks have not been developed.

Changes in v15:
	- Fix use of uninitialized variable in patch 3/9

Changes in v14:
	- Remove duplicate entries from pdev->reset_methods as per
	  Shanker's suggestion

Changes in v13:
	- Added "PCI: Cache PCIe FLR capability"
	- Removed memcpy in pci_init_reset_methods() and reset_method_show
	- Moved reset_method sysfs attribute code from pci-sysfs.c to
	  pci.c

Changes in v12:
        - Corrected subject in 0/8 (cover letter).

Changes in v11:
        - Alex's suggestion fallback back to other resets if the ACPI RST
          fails. Fix "s/-EINVAL/-ENOTTY/" in 7/8 patch.

Changes in v10:
        - Fix build error on ppc as reported by build bot

Changes in v9:
        - Renamed has_flr bitfield to has_pcie_flr and restored
          use of PCI_DEV_FLAGS_NO_FLR_RESET in quirk_no_flr()
        - Cleaned up sysfs code

Changes in v8:
        - Added has_flr bitfield to struct pci_dev to cache flr
          capability
        - Updated encoding scheme used in reset_methods array as per
          Bjorn's suggestion
        - Updated Shanker's ACPI patches

Changes in v7:
        - Fix the pci_dev_acpi_reset() prototype mismatch
          in case of CONFIG_ACPI=n

Changes in v6:
        - Address Bjorn's and Krzysztof's review comments
        - Add Shanker's updated patches along with new
          "PCI: Setup ACPI_COMPANION early" patch

Changes in v5:
        - Rebase the series over pci/reset branch of
          Bjorn's pci tree to avoid merge conflicts
          caused by recent changes in existing reset
          sysfs attribute

Changes in v4:
        - Change the order or strlen and strim in reset_method_store
          function to avoid extra strlen call.
        - Use consistent terminology in new
          pci_reset_mode enum and rename the probe argument
          of reset functions.

Changes in v3:
        - Dropped "PCI: merge slot and bus reset implementations" which was
          already accepted separately
        - Grammar fixes
        - Added Shanker's patches which were rebased on v2 of this series
        - Added "PCI: Change the type of probe argument in reset functions"
          and additional user input sanitization code in reset_method_store
          function per review feedback from Krzysztof

Changes in v2:
        - Use byte array instead of bitmap to keep track of
          ordering of reset methods
        - Fix incorrect use of reset_fn field in octeon driver
        - Allow writing comma separated list of names of supported reset
          methods to reset_method sysfs attribute
        - Writing empty string instead of "none" to reset_method attribute
          disables ability of reset the device

Amey Narkhede (6):
  PCI: Cache PCIe FLR capability
  PCI: Add pcie_reset_flr to follow calling convention of other reset
    methods
  PCI: Add new array for keeping track of ordering of reset methods
  PCI: Remove reset_fn field from pci_dev
  PCI: Allow userspace to query and set device reset mechanism
  PCI: Change the type of probe argument in reset functions

Shanker Donthineni (3):
  PCI: Define a function to set ACPI_COMPANION in pci_dev
  PCI: Setup ACPI fwnode early and at the same time with OF
  PCI: Add support for ACPI _RST reset method

 Documentation/ABI/testing/sysfs-bus-pci       |  19 ++
 drivers/crypto/cavium/nitrox/nitrox_main.c    |   4 +-
 .../ethernet/cavium/liquidio/lio_vf_main.c    |   2 +-
 drivers/pci/hotplug/pciehp.h                  |   2 +-
 drivers/pci/hotplug/pciehp_hpc.c              |   2 +-
 drivers/pci/hotplug/pnv_php.c                 |   4 +-
 drivers/pci/pci-acpi.c                        |  35 ++-
 drivers/pci/pci-sysfs.c                       |   3 +-
 drivers/pci/pci.c                             | 287 +++++++++++++-----
 drivers/pci/pci.h                             |  24 +-
 drivers/pci/pcie/aer.c                        |  12 +-
 drivers/pci/probe.c                           |  16 +-
 drivers/pci/quirks.c                          |  25 +-
 drivers/pci/remove.c                          |   1 -
 include/linux/pci.h                           |  14 +-
 include/linux/pci_hotplug.h                   |   2 +-
 16 files changed, 332 insertions(+), 120 deletions(-)

--
2.32.0

^ permalink raw reply	[flat|nested] 21+ messages in thread
* [PATCH v15 1/9] PCI: Cache PCIe FLR capability
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-09 11:13   ` Raphael Norwitz
  2021-08-05 16:29 ` [PATCH v15 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
                   ` (8 subsequent siblings)
  9 siblings, 1 reply; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

Add a new member called devcap in struct pci_dev for caching the device
capabilities to avoid reading PCI_EXP_DEVCAP multiple times.

Refactor pcie_has_flr() to use cached device capabilities.

Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/pci/pci.c   | 6 ++----
 drivers/pci/probe.c | 5 +++--
 include/linux/pci.h | 1 +
 3 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 452351025a09..1fafd05caa41 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -31,6 +31,7 @@
 #include <linux/vmalloc.h>
 #include <asm/dma.h>
 #include <linux/aer.h>
+#include <linux/bitfield.h>
 #include "pci.h"
 
 DEFINE_MUTEX(pci_slot_mutex);
@@ -4620,13 +4621,10 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
  */
 bool pcie_has_flr(struct pci_dev *dev)
 {
-	u32 cap;
-
 	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
 		return false;
 
-	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
-	return cap & PCI_EXP_DEVCAP_FLR;
+	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
 }
 EXPORT_SYMBOL_GPL(pcie_has_flr);
 
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 3a62d09b8869..df3f9db6e151 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -19,6 +19,7 @@
 #include <linux/hypervisor.h>
 #include <linux/irqdomain.h>
 #include <linux/pm_runtime.h>
+#include <linux/bitfield.h>
 #include "pci.h"
 
 #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
@@ -1497,8 +1498,8 @@ void set_pcie_port_type(struct pci_dev *pdev)
 	pdev->pcie_cap = pos;
 	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
 	pdev->pcie_flags_reg = reg16;
-	pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
-	pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
+	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap);
+	pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);
 
 	parent = pci_upstream_bridge(pdev);
 	if (!parent)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c20211e59a57..697b1f085c7b 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -333,6 +333,7 @@ struct pci_dev {
 	struct rcec_ea	*rcec_ea;	/* RCEC cached endpoint association */
 	struct pci_dev  *rcec;          /* Associated RCEC device */
 #endif
+	u32		devcap;		/* PCIe device capabilities */
 	u8		pcie_cap;	/* PCIe capability offset */
 	u8		msi_cap;	/* MSI capability offset */
 	u8		msix_cap;	/* MSI-X capability offset */
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 1/9] PCI: Cache PCIe FLR capability Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-09 11:15   ` Raphael Norwitz
  2021-08-05 16:29 ` [PATCH v15 3/9] PCI: Add new array for keeping track of ordering of " Amey Narkhede
                   ` (7 subsequent siblings)
  9 siblings, 1 reply; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

Currently there is separate function pcie_has_flr() to probe if PCIe FLR
is supported by the device which does not match the calling convention
followed by reset methods which use second function argument to decide
whether to probe or not. Add new function pcie_reset_flr() that follows
the calling convention of reset methods.

Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/crypto/cavium/nitrox/nitrox_main.c |  4 +--
 drivers/pci/pci.c                          | 40 +++++++++++++++-------
 drivers/pci/pcie/aer.c                     | 12 +++----
 drivers/pci/quirks.c                       |  9 ++---
 include/linux/pci.h                        |  2 +-
 5 files changed, 38 insertions(+), 29 deletions(-)

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index facc8e6bc580..15d6c8452807 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_main.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
@@ -306,9 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
 		return -ENOMEM;
 	}
 
-	/* check flr support */
-	if (pcie_has_flr(pdev))
-		pcie_flr(pdev);
+	pcie_reset_flr(pdev, 0);
 
 	pci_restore_state(pdev);
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1fafd05caa41..7d1d9671160b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4619,22 +4619,20 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
  * Returns true if the device advertises support for PCIe function level
  * resets.
  */
-bool pcie_has_flr(struct pci_dev *dev)
+static bool pcie_has_flr(struct pci_dev *dev)
 {
 	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
 		return false;
 
 	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
 }
-EXPORT_SYMBOL_GPL(pcie_has_flr);
 
 /**
  * pcie_flr - initiate a PCIe function level reset
  * @dev: device to reset
  *
- * Initiate a function level reset on @dev.  The caller should ensure the
- * device supports FLR before calling this function, e.g. by using the
- * pcie_has_flr() helper.
+ * Initiate a function level reset unconditionally on @dev without
+ * checking any flags and DEVCAP
  */
 int pcie_flr(struct pci_dev *dev)
 {
@@ -4657,6 +4655,25 @@ int pcie_flr(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pcie_flr);
 
+/**
+ * pcie_reset_flr - initiate a PCIe function level reset
+ * @dev: device to reset
+ * @probe: If set, only check if the device can be reset this way.
+ *
+ * Initiate a function level reset on @dev.
+ */
+int pcie_reset_flr(struct pci_dev *dev, int probe)
+{
+	if (!pcie_has_flr(dev))
+		return -ENOTTY;
+
+	if (probe)
+		return 0;
+
+	return pcie_flr(dev);
+}
+EXPORT_SYMBOL_GPL(pcie_reset_flr);
+
 static int pci_af_flr(struct pci_dev *dev, int probe)
 {
 	int pos;
@@ -5137,11 +5154,9 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 	rc = pci_dev_specific_reset(dev, 0);
 	if (rc != -ENOTTY)
 		return rc;
-	if (pcie_has_flr(dev)) {
-		rc = pcie_flr(dev);
-		if (rc != -ENOTTY)
-			return rc;
-	}
+	rc = pcie_reset_flr(dev, 0);
+	if (rc != -ENOTTY)
+		return rc;
 	rc = pci_af_flr(dev, 0);
 	if (rc != -ENOTTY)
 		return rc;
@@ -5172,8 +5187,9 @@ int pci_probe_reset_function(struct pci_dev *dev)
 	rc = pci_dev_specific_reset(dev, 1);
 	if (rc != -ENOTTY)
 		return rc;
-	if (pcie_has_flr(dev))
-		return 0;
+	rc = pcie_reset_flr(dev, 1);
+	if (rc != -ENOTTY)
+		return rc;
 	rc = pci_af_flr(dev, 1);
 	if (rc != -ENOTTY)
 		return rc;
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index ec943cee5ecc..98077595a73e 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1405,13 +1405,11 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	}
 
 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
-		if (pcie_has_flr(dev)) {
-			rc = pcie_flr(dev);
-			pci_info(dev, "has been reset (%d)\n", rc);
-		} else {
-			pci_info(dev, "not reset (no FLR support)\n");
-			rc = -ENOTTY;
-		}
+		rc = pcie_reset_flr(dev, 0);
+		if (!rc)
+			pci_info(dev, "has been reset\n");
+		else
+			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
 	} else {
 		rc = pci_bus_error_reset(dev);
 		pci_info(dev, "%s Port link has been reset (%d)\n",
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d85914afe65a..b48e7ef8b641 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3819,7 +3819,7 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
 	u32 cfg;
 
 	if (dev->class != PCI_CLASS_STORAGE_EXPRESS ||
-	    !pcie_has_flr(dev) || !pci_resource_start(dev, 0))
+	    pcie_reset_flr(dev, 1) || !pci_resource_start(dev, 0))
 		return -ENOTTY;
 
 	if (probe)
@@ -3888,13 +3888,10 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
  */
 static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
 {
-	if (!pcie_has_flr(dev))
-		return -ENOTTY;
-
 	if (probe)
-		return 0;
+		return pcie_reset_flr(dev, 1);
 
-	pcie_flr(dev);
+	pcie_reset_flr(dev, 0);
 
 	msleep(250);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 697b1f085c7b..aa85e7d3147e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1226,7 +1226,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 			     enum pci_bus_speed *speed,
 			     enum pcie_link_width *width);
 void pcie_print_link_status(struct pci_dev *dev);
-bool pcie_has_flr(struct pci_dev *dev);
+int pcie_reset_flr(struct pci_dev *dev, int probe);
 int pcie_flr(struct pci_dev *dev);
 int __pci_reset_function_locked(struct pci_dev *dev);
 int pci_reset_function(struct pci_dev *dev);
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 3/9] PCI: Add new array for keeping track of ordering of reset methods
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 1/9] PCI: Cache PCIe FLR capability Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-09 11:18   ` Raphael Norwitz
  2021-08-05 16:29 ` [PATCH v15 4/9] PCI: Remove reset_fn field from pci_dev Amey Narkhede
                   ` (6 subsequent siblings)
  9 siblings, 1 reply; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

Introduce a new array reset_methods in struct pci_dev to keep track of
reset mechanisms supported by the device and their ordering.

Also refactor probing and reset functions to take advantage of calling
convention of reset functions.

Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/pci/pci.c   | 95 ++++++++++++++++++++++++++-------------------
 drivers/pci/pci.h   |  8 +++-
 drivers/pci/probe.c |  5 +--
 include/linux/pci.h |  7 ++++
 4 files changed, 71 insertions(+), 44 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 7d1d9671160b..67eab3d29cb3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -73,6 +73,11 @@ static void pci_dev_d3_sleep(struct pci_dev *dev)
 		msleep(delay);
 }
 
+bool pci_reset_supported(struct pci_dev *dev)
+{
+	return dev->reset_methods[0] != 0;
+}
+
 #ifdef CONFIG_PCI_DOMAINS
 int pci_domains_supported = 1;
 #endif
@@ -5117,6 +5122,16 @@ static void pci_dev_restore(struct pci_dev *dev)
 		err_handler->reset_done(dev);
 }
 
+/* dev->reset_methods[] is a 0-terminated list of indices into this array */
+static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
+	{ },
+	{ pci_dev_specific_reset, .name = "device_specific" },
+	{ pcie_reset_flr, .name = "flr" },
+	{ pci_af_flr, .name = "af_flr" },
+	{ pci_pm_reset, .name = "pm" },
+	{ pci_reset_bus_function, .name = "bus" },
+};
+
 /**
  * __pci_reset_function_locked - reset a PCI device function while holding
  * the @dev mutex lock.
@@ -5139,65 +5154,65 @@ static void pci_dev_restore(struct pci_dev *dev)
  */
 int __pci_reset_function_locked(struct pci_dev *dev)
 {
-	int rc;
+	int i, m, rc = -ENOTTY;
 
 	might_sleep();
 
 	/*
-	 * A reset method returns -ENOTTY if it doesn't support this device
-	 * and we should try the next method.
+	 * A reset method returns -ENOTTY if it doesn't support this device and
+	 * we should try the next method.
 	 *
-	 * If it returns 0 (success), we're finished.  If it returns any
-	 * other error, we're also finished: this indicates that further
-	 * reset mechanisms might be broken on the device.
+	 * If it returns 0 (success), we're finished.  If it returns any other
+	 * error, we're also finished: this indicates that further reset
+	 * mechanisms might be broken on the device.
 	 */
-	rc = pci_dev_specific_reset(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pcie_reset_flr(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_af_flr(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_pm_reset(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	return pci_reset_bus_function(dev, 0);
+	for (i = 0; i <  PCI_NUM_RESET_METHODS; i++) {
+		m = dev->reset_methods[i];
+		if (!m)
+			return -ENOTTY;
+
+		rc = pci_reset_fn_methods[m].reset_fn(dev, 0);
+		if (!rc)
+			return 0;
+		if (rc != -ENOTTY)
+			return rc;
+	}
+
+	return -ENOTTY;
 }
 EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
 
 /**
- * pci_probe_reset_function - check whether the device can be safely reset
- * @dev: PCI device to reset
+ * pci_init_reset_methods - check whether device can be safely reset
+ * and store supported reset mechanisms.
+ * @dev: PCI device to check for reset mechanisms
  *
  * Some devices allow an individual function to be reset without affecting
- * other functions in the same device.  The PCI device must be responsive
- * to PCI config space in order to use this function.
+ * other functions in the same device.  The PCI device must be in D0-D3hot
+ * state.
  *
- * Returns 0 if the device function can be reset or negative if the
- * device doesn't support resetting a single function.
+ * Stores reset mechanisms supported by device in reset_methods byte array
+ * which is a member of struct pci_dev.
  */
-int pci_probe_reset_function(struct pci_dev *dev)
+void pci_init_reset_methods(struct pci_dev *dev)
 {
-	int rc;
+	int m, i, rc;
+
+	BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS);
 
 	might_sleep();
 
-	rc = pci_dev_specific_reset(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pcie_reset_flr(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_af_flr(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_pm_reset(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
+	i = 0;
+
+	for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
+		rc = pci_reset_fn_methods[m].reset_fn(dev, 1);
+		if (!rc)
+			dev->reset_methods[i++] = m;
+		else if (rc != -ENOTTY)
+			break;
+	}
 
-	return pci_reset_bus_function(dev, 1);
+	dev->reset_methods[i] = 0;
 }
 
 /**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 37c913bbc6e1..7438953745e0 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -33,7 +33,8 @@ enum pci_mmap_api {
 int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
 		  enum pci_mmap_api mmap_api);
 
-int pci_probe_reset_function(struct pci_dev *dev);
+bool pci_reset_supported(struct pci_dev *dev);
+void pci_init_reset_methods(struct pci_dev *dev);
 int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
 int pci_bus_error_reset(struct pci_dev *dev);
 
@@ -606,6 +607,11 @@ struct pci_dev_reset_methods {
 	int (*reset)(struct pci_dev *dev, int probe);
 };
 
+struct pci_reset_fn_method {
+	int (*reset_fn)(struct pci_dev *pdev, int probe);
+	char *name;
+};
+
 #ifdef CONFIG_PCI_QUIRKS
 int pci_dev_specific_reset(struct pci_dev *dev, int probe);
 #else
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index df3f9db6e151..5d8ad230f7d0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2405,9 +2405,8 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_rcec_init(dev);		/* Root Complex Event Collector */
 
 	pcie_report_downtraining(dev);
-
-	if (pci_probe_reset_function(dev) == 0)
-		dev->reset_fn = 1;
+	pci_init_reset_methods(dev);
+	dev->reset_fn = pci_reset_supported(dev);
 }
 
 /*
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aa85e7d3147e..d1a9a232d08e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -49,6 +49,9 @@
 			       PCI_STATUS_SIG_TARGET_ABORT | \
 			       PCI_STATUS_PARITY)
 
+/* Number of reset methods used in pci_reset_fn_methods array in pci.c */
+#define PCI_NUM_RESET_METHODS 6
+
 /*
  * The PCI interface treats multi-function devices as independent
  * devices.  The slot/function address of each device is encoded
@@ -506,6 +509,10 @@ struct pci_dev {
 	char		*driver_override; /* Driver name to force a match */
 
 	unsigned long	priv_flags;	/* Private flags for the PCI driver */
+	/*
+	 * See pci_reset_fn_methods array in pci.c for ordering.
+	 */
+	u8 reset_methods[PCI_NUM_RESET_METHODS];	/* Reset methods ordered by priority */
 };
 
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 4/9] PCI: Remove reset_fn field from pci_dev
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (2 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 3/9] PCI: Add new array for keeping track of ordering of " Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 5/9] PCI: Allow userspace to query and set device reset mechanism Amey Narkhede
                   ` (5 subsequent siblings)
  9 siblings, 0 replies; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

reset_fn field is used to indicate whether the device supports any reset
mechanism or not. Remove the use of reset_fn in favor of new reset_methods
array which can be used to keep track of all supported reset mechanisms of
a device and their ordering.

The octeon driver is incorrectly using reset_fn field to detect if the
device supports FLR or not. Use pcie_reset_flr() to probe whether it
supports FLR or not.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/net/ethernet/cavium/liquidio/lio_vf_main.c | 2 +-
 drivers/pci/pci-sysfs.c                            | 2 +-
 drivers/pci/pci.c                                  | 6 +++---
 drivers/pci/probe.c                                | 1 -
 drivers/pci/quirks.c                               | 2 +-
 drivers/pci/remove.c                               | 1 -
 include/linux/pci.h                                | 1 -
 7 files changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 516f166ceff8..336d149ee2e2 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -526,7 +526,7 @@ static void octeon_destroy_resources(struct octeon_device *oct)
 			oct->irq_name_storage = NULL;
 		}
 		/* Soft reset the octeon device before exiting */
-		if (oct->pci_dev->reset_fn)
+		if (!pcie_reset_flr(oct->pci_dev, 1))
 			octeon_pci_flr(oct);
 		else
 			cn23xx_vf_ask_pf_to_do_flr(oct);
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index beb8d1f4fafe..316f70c3e3b4 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1367,7 +1367,7 @@ static umode_t pci_dev_reset_attr_is_visible(struct kobject *kobj,
 {
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 
-	if (!pdev->reset_fn)
+	if (!pci_reset_supported(pdev))
 		return 0;
 
 	return a->mode;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 67eab3d29cb3..8a516e9ca316 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5235,7 +5235,7 @@ int pci_reset_function(struct pci_dev *dev)
 {
 	int rc;
 
-	if (!dev->reset_fn)
+	if (!pci_reset_supported(dev))
 		return -ENOTTY;
 
 	pci_dev_lock(dev);
@@ -5271,7 +5271,7 @@ int pci_reset_function_locked(struct pci_dev *dev)
 {
 	int rc;
 
-	if (!dev->reset_fn)
+	if (!pci_reset_supported(dev))
 		return -ENOTTY;
 
 	pci_dev_save_and_disable(dev);
@@ -5294,7 +5294,7 @@ int pci_try_reset_function(struct pci_dev *dev)
 {
 	int rc;
 
-	if (!dev->reset_fn)
+	if (!pci_reset_supported(dev))
 		return -ENOTTY;
 
 	if (!pci_dev_trylock(dev))
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5d8ad230f7d0..379e85037d9b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2406,7 +2406,6 @@ static void pci_init_capabilities(struct pci_dev *dev)
 
 	pcie_report_downtraining(dev);
 	pci_init_reset_methods(dev);
-	dev->reset_fn = pci_reset_supported(dev);
 }
 
 /*
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b48e7ef8b641..0db5dac3ddce 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5589,7 +5589,7 @@ static void quirk_reset_lenovo_thinkpad_p50_nvgpu(struct pci_dev *pdev)
 
 	if (pdev->subsystem_vendor != PCI_VENDOR_ID_LENOVO ||
 	    pdev->subsystem_device != 0x222e ||
-	    !pdev->reset_fn)
+	    !pci_reset_supported(pdev))
 		return;
 
 	if (pci_enable_device_mem(pdev))
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index dd12c2fcc7dc..4c54c75050dc 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -19,7 +19,6 @@ static void pci_stop_dev(struct pci_dev *dev)
 	pci_pme_active(dev, false);
 
 	if (pci_dev_is_added(dev)) {
-		dev->reset_fn = 0;
 
 		device_release_driver(&dev->dev);
 		pci_proc_detach_device(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d1a9a232d08e..94d74fd594c1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -431,7 +431,6 @@ struct pci_dev {
 	unsigned int	state_saved:1;
 	unsigned int	is_physfn:1;
 	unsigned int	is_virtfn:1;
-	unsigned int	reset_fn:1;
 	unsigned int	is_hotplug_bridge:1;
 	unsigned int	shpc_managed:1;		/* SHPC owned by shpchp */
 	unsigned int	is_thunderbolt:1;	/* Thunderbolt controller */
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 5/9] PCI: Allow userspace to query and set device reset mechanism
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (3 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 4/9] PCI: Remove reset_fn field from pci_dev Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-09 11:23   ` Raphael Norwitz
  2021-08-05 16:29 ` [PATCH v15 6/9] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
                   ` (4 subsequent siblings)
  9 siblings, 1 reply; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

Add reset_method sysfs attribute to enable user to query and set user
preferred device reset methods and their ordering.

Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 Documentation/ABI/testing/sysfs-bus-pci |  19 ++++
 drivers/pci/pci-sysfs.c                 |   1 +
 drivers/pci/pci.c                       | 117 ++++++++++++++++++++++++
 drivers/pci/pci.h                       |   2 +
 4 files changed, 139 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ef00fada2efb..ef66b62bf025 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -121,6 +121,25 @@ Description:
 		child buses, and re-discover devices removed earlier
 		from this part of the device tree.

+What:		/sys/bus/pci/devices/.../reset_method
+Date:		March 2021
+Contact:	Amey Narkhede <ameynarkhede03@gmail.com>
+Description:
+		Some devices allow an individual function to be reset
+		without affecting other functions in the same slot.
+
+		For devices that have this support, a file named
+		reset_method will be present in sysfs. Initially reading
+		this file will give names of the device supported reset
+		methods and their ordering. After write, this file will
+		give names and ordering of currently enabled reset methods.
+		Writing the name or space separated list of names of any of
+		the device supported reset methods to this file will set
+		the reset methods and their ordering to be used when
+		resetting the device. Writing empty string to this file
+		will disable ability to reset the device and writing
+		"default" will return to the original value.
+
 What:		/sys/bus/pci/devices/.../reset
 Date:		July 2009
 Contact:	Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 316f70c3e3b4..54ee7193b463 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1491,6 +1491,7 @@ const struct attribute_group *pci_dev_groups[] = {
 	&pci_dev_config_attr_group,
 	&pci_dev_rom_attr_group,
 	&pci_dev_reset_attr_group,
+	&pci_dev_reset_method_attr_group,
 	&pci_dev_vpd_attr_group,
 #ifdef CONFIG_DMI
 	&pci_dev_smbios_attr_group,
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 8a516e9ca316..53d73770881f 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5132,6 +5132,123 @@ static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
 	{ pci_reset_bus_function, .name = "bus" },
 };

+static ssize_t reset_method_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	ssize_t len = 0;
+	int i, m;
+
+	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
+		m = pdev->reset_methods[i];
+		if (!m)
+			break;
+
+		len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
+				     pci_reset_fn_methods[m].name);
+	}
+
+	if (len)
+		len += sysfs_emit_at(buf, len, "\n");
+
+	return len;
+}
+
+static ssize_t reset_method_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int i, m = 0, n = 0;
+	char *name, *options;
+
+	if (count >= (PAGE_SIZE - 1))
+		return -EINVAL;
+
+	if (sysfs_streq(buf, "")) {
+		goto exit;
+	}
+
+	if (sysfs_streq(buf, "default")) {
+		pci_init_reset_methods(pdev);
+		return count;
+	}
+
+	options = kstrndup(buf, count, GFP_KERNEL);
+	if (!options)
+		return -ENOMEM;
+
+	while ((name = strsep(&options, " ")) != NULL) {
+		if (sysfs_streq(name, ""))
+			continue;
+
+		name = strim(name);
+
+		for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
+			if (sysfs_streq(name, pci_reset_fn_methods[m].name))
+				break;
+		}
+
+		if (m == PCI_NUM_RESET_METHODS) {
+			pci_warn(pdev, "Skip invalid reset method '%s'", name);
+			continue;
+		}
+
+		for (i = 0; i < n; i++) {
+			if (pdev->reset_methods[i] == m)
+				break;
+		}
+
+		if (i < n)
+			continue;
+
+		if (pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
+			pci_warn(pdev, "Unsupported reset method '%s'", name);
+			continue;
+		}
+
+		pdev->reset_methods[n++] = m;
+		BUG_ON(n == PCI_NUM_RESET_METHODS);
+	}
+
+	kfree(options);
+
+exit:
+	/* All the reset methods are invalid */
+	if (n == 0 && m == PCI_NUM_RESET_METHODS)
+		return -EINVAL;
+	pdev->reset_methods[n] = 0;
+	if (pdev->reset_methods[0] == 0) {
+		pci_warn(pdev, "All device reset methods disabled by user");
+	} else if ((pdev->reset_methods[0] != 1) &&
+		   !pci_reset_fn_methods[1].reset_fn(pdev, 1)) {
+		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
+	}
+	return count;
+}
+static DEVICE_ATTR_RW(reset_method);
+
+static struct attribute *pci_dev_reset_method_attrs[] = {
+	&dev_attr_reset_method.attr,
+	NULL,
+};
+
+static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,
+						    struct attribute *a, int n)
+{
+	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
+
+	if (!pci_reset_supported(pdev))
+		return 0;
+
+	return a->mode;
+}
+
+const struct attribute_group pci_dev_reset_method_attr_group = {
+	.attrs = pci_dev_reset_method_attrs,
+	.is_visible = pci_dev_reset_method_attr_is_visible,
+};
+
 /**
  * __pci_reset_function_locked - reset a PCI device function while holding
  * the @dev mutex lock.
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 7438953745e0..31458d48eda7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -714,4 +714,6 @@ static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 extern const struct attribute_group aspm_ctrl_attr_group;
 #endif

+extern const struct attribute_group pci_dev_reset_method_attr_group;
+
 #endif /* DRIVERS_PCI_H */
--
2.32.0

^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 6/9] PCI: Define a function to set ACPI_COMPANION in pci_dev
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (4 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 5/9] PCI: Allow userspace to query and set device reset mechanism Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
                   ` (3 subsequent siblings)
  9 siblings, 0 replies; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki

From: Shanker Donthineni <sdonthineni@nvidia.com>

Move the existing code logic from acpi_pci_bridge_d3() to a separate
function pci_set_acpi_fwnode() to set the ACPI fwnode.

No functional change with this patch.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/pci/pci-acpi.c | 12 ++++++++----
 drivers/pci/pci.h      |  2 ++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 36bc23e21759..eaddbf701759 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -934,6 +934,13 @@ static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
 
 static struct acpi_device *acpi_pci_find_companion(struct device *dev);
 
+void pci_set_acpi_fwnode(struct pci_dev *dev)
+{
+	if (!ACPI_COMPANION(&dev->dev) && !pci_dev_is_added(dev))
+		ACPI_COMPANION_SET(&dev->dev,
+				   acpi_pci_find_companion(&dev->dev));
+}
+
 static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 {
 	const struct fwnode_handle *fwnode;
@@ -945,11 +952,8 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 		return false;
 
 	/* Assume D3 support if the bridge is power-manageable by ACPI. */
+	pci_set_acpi_fwnode(dev);
 	adev = ACPI_COMPANION(&dev->dev);
-	if (!adev && !pci_dev_is_added(dev)) {
-		adev = acpi_pci_find_companion(&dev->dev);
-		ACPI_COMPANION_SET(&dev->dev, adev);
-	}
 
 	if (adev && acpi_device_power_manageable(adev))
 		return true;
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 31458d48eda7..8ef379b6cfad 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -703,7 +703,9 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
 #ifdef CONFIG_ACPI
 int pci_acpi_program_hp_params(struct pci_dev *dev);
 extern const struct attribute_group pci_dev_acpi_attr_group;
+void pci_set_acpi_fwnode(struct pci_dev *dev);
 #else
+static inline void pci_set_acpi_fwnode(struct pci_dev *dev) {}
 static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 {
 	return -ENODEV;
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (5 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 6/9] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-13 23:04   ` Bjorn Helgaas
  2021-08-05 16:29 ` [PATCH v15 8/9] PCI: Add support for ACPI _RST reset method Amey Narkhede
                   ` (2 subsequent siblings)
  9 siblings, 1 reply; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki

From: Shanker Donthineni <sdonthineni@nvidia.com>

The pci_dev objects are created through two mechanisms 1) during PCI
bus scan and 2) from I/O Virtualization. The fwnode in pci_dev object
is being set at different places depends on the type of firmware used,
device creation mechanism, and acpi_pci_bridge_d3().

The software features which have a dependency on ACPI fwnode properties
and need to be handled before device_add() will not work. One use case,
the software has to check the existence of _RST method to support ACPI
based reset method.

This patch does the two changes in order to provide fwnode consistently.
 - Set ACPI and OF fwnodes from pci_setup_device().
 - Remove pci_set_acpi_fwnode() in acpi_pci_bridge_d3().

After this patch, ACPI/OF firmware properties are visible at the same
time during the early stage of pci_dev setup. And also call sites should
be able to use firmware agnostic functions device_property_xxx() for the
early PCI quirks in the future.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/pci/pci-acpi.c | 1 -
 drivers/pci/probe.c    | 7 ++++---
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index eaddbf701759..dae021322b3f 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 		return false;
 
 	/* Assume D3 support if the bridge is power-manageable by ACPI. */
-	pci_set_acpi_fwnode(dev);
 	adev = ACPI_COMPANION(&dev->dev);
 
 	if (adev && acpi_device_power_manageable(adev))
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 379e85037d9b..15a6975d3757 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1789,6 +1789,9 @@ int pci_setup_device(struct pci_dev *dev)
 	dev->error_state = pci_channel_io_normal;
 	set_pcie_port_type(dev);
 
+	pci_set_of_node(dev);
+	pci_set_acpi_fwnode(dev);
+
 	pci_dev_assign_slot(dev);
 
 	/*
@@ -1924,6 +1927,7 @@ int pci_setup_device(struct pci_dev *dev)
 	default:				    /* unknown header */
 		pci_err(dev, "unknown header type %02x, ignoring device\n",
 			dev->hdr_type);
+		pci_release_of_node(dev);
 		return -EIO;
 
 	bad:
@@ -2351,10 +2355,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
 	dev->vendor = l & 0xffff;
 	dev->device = (l >> 16) & 0xffff;
 
-	pci_set_of_node(dev);
-
 	if (pci_setup_device(dev)) {
-		pci_release_of_node(dev);
 		pci_bus_put(dev->bus);
 		kfree(dev);
 		return NULL;
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 8/9] PCI: Add support for ACPI _RST reset method
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (6 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-05 16:29 ` [PATCH v15 9/9] PCI: Change the type of probe argument in reset functions Amey Narkhede
  2021-08-12 13:03 ` [PATCH v15 0/9] PCI: Expose and manage PCI device reset Shanker R Donthineni
  9 siblings, 0 replies; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki

From: Shanker Donthineni <sdonthineni@nvidia.com>

The _RST is a standard method specified in the ACPI specification. It
provides a function level reset when it is described in the acpi_device
context associated with PCI-device. Implement a new reset function
pci_dev_acpi_reset() for probing RST method and execute if it is defined
in the firmware.

The default priority of the ACPI reset is set to below device-specific
and above hardware resets.

Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Reviewed-by: Sinan Kaya <okaya@kernel.org>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
---
 drivers/pci/pci-acpi.c | 23 +++++++++++++++++++++++
 drivers/pci/pci.c      |  1 +
 drivers/pci/pci.h      |  6 ++++++
 include/linux/pci.h    |  2 +-
 4 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index dae021322b3f..31f76746741f 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -941,6 +941,29 @@ void pci_set_acpi_fwnode(struct pci_dev *dev)
 				   acpi_pci_find_companion(&dev->dev));
 }
 
+/**
+ * pci_dev_acpi_reset - do a function level reset using _RST method
+ * @dev: device to reset
+ * @probe: check if _RST method is included in the acpi_device context.
+ */
+int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+{
+	acpi_handle handle = ACPI_HANDLE(&dev->dev);
+
+	if (!handle || !acpi_has_method(handle, "_RST"))
+		return -ENOTTY;
+
+	if (probe)
+		return 0;
+
+	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) {
+		pci_warn(dev, "ACPI _RST failed\n");
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
 static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 {
 	const struct fwnode_handle *fwnode;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 53d73770881f..5f76d04fa864 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5126,6 +5126,7 @@ static void pci_dev_restore(struct pci_dev *dev)
 static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
 	{ },
 	{ pci_dev_specific_reset, .name = "device_specific" },
+	{ pci_dev_acpi_reset, .name = "acpi" },
 	{ pcie_reset_flr, .name = "flr" },
 	{ pci_af_flr, .name = "af_flr" },
 	{ pci_pm_reset, .name = "pm" },
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 8ef379b6cfad..b13dae3323da 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -704,7 +704,13 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
 int pci_acpi_program_hp_params(struct pci_dev *dev);
 extern const struct attribute_group pci_dev_acpi_attr_group;
 void pci_set_acpi_fwnode(struct pci_dev *dev);
+int pci_dev_acpi_reset(struct pci_dev *dev, int probe);
 #else
+static inline int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+{
+	return -ENOTTY;
+}
+
 static inline void pci_set_acpi_fwnode(struct pci_dev *dev) {}
 static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 94d74fd594c1..d3b06bfd8b99 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -50,7 +50,7 @@
 			       PCI_STATUS_PARITY)
 
 /* Number of reset methods used in pci_reset_fn_methods array in pci.c */
-#define PCI_NUM_RESET_METHODS 6
+#define PCI_NUM_RESET_METHODS 7
 
 /*
  * The PCI interface treats multi-function devices as independent
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* [PATCH v15 9/9] PCI: Change the type of probe argument in reset functions
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (7 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 8/9] PCI: Add support for ACPI _RST reset method Amey Narkhede
@ 2021-08-05 16:29 ` Amey Narkhede
  2021-08-14 14:05   ` Shanker R Donthineni
  2021-08-12 13:03 ` [PATCH v15 0/9] PCI: Expose and manage PCI device reset Shanker R Donthineni
  9 siblings, 1 reply; 21+ messages in thread
From: Amey Narkhede @ 2021-08-05 16:29 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Amey Narkhede

Change the type of probe argument in functions which implement reset
methods from int to bool to make the context and intent clear.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Suggested-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/crypto/cavium/nitrox/nitrox_main.c    |  2 +-
 .../ethernet/cavium/liquidio/lio_vf_main.c    |  2 +-
 drivers/pci/hotplug/pciehp.h                  |  2 +-
 drivers/pci/hotplug/pciehp_hpc.c              |  2 +-
 drivers/pci/hotplug/pnv_php.c                 |  4 +-
 drivers/pci/pci-acpi.c                        |  5 +-
 drivers/pci/pci.c                             | 52 +++++++++----------
 drivers/pci/pci.h                             | 12 ++---
 drivers/pci/pcie/aer.c                        |  2 +-
 drivers/pci/quirks.c                          | 20 +++----
 include/linux/pci.h                           |  5 +-
 include/linux/pci_hotplug.h                   |  2 +-
 12 files changed, 57 insertions(+), 53 deletions(-)

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index 15d6c8452807..f97fa8e997b5 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_main.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
@@ -306,7 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
 		return -ENOMEM;
 	}
 
-	pcie_reset_flr(pdev, 0);
+	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 
 	pci_restore_state(pdev);
 
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 336d149ee2e2..6e666be6907a 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -526,7 +526,7 @@ static void octeon_destroy_resources(struct octeon_device *oct)
 			oct->irq_name_storage = NULL;
 		}
 		/* Soft reset the octeon device before exiting */
-		if (!pcie_reset_flr(oct->pci_dev, 1))
+		if (!pcie_reset_flr(oct->pci_dev, PCI_RESET_PROBE))
 			octeon_pci_flr(oct);
 		else
 			cn23xx_vf_ask_pf_to_do_flr(oct);
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 4fd200d8b0a9..23d6d6813edf 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -181,7 +181,7 @@ void pciehp_release_ctrl(struct controller *ctrl);
 
 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
-int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
+int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe);
 int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status);
 int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
 int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
index fb3840e222ad..d9f782b2e203 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -834,7 +834,7 @@ void pcie_disable_interrupt(struct controller *ctrl)
  * momentarily, if we see that they could interfere. Also, clear any spurious
  * events after.
  */
-int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe)
+int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
 {
 	struct controller *ctrl = to_ctrl(hotplug_slot);
 	struct pci_dev *pdev = ctrl_dev(ctrl);
diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index 04565162a449..4c17a5dc26cf 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -526,7 +526,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
 	return 0;
 }
 
-static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
+static int pnv_php_reset_slot(struct hotplug_slot *slot, bool probe)
 {
 	struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
 	struct pci_dev *bridge = php_slot->pdev;
@@ -537,7 +537,7 @@ static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
 	 * which don't have a bridge. Only claim to support
 	 * reset_slot() if we have a bridge device (for now...)
 	 */
-	if (probe)
+	if (probe == PCI_RESET_PROBE)
 		return !bridge;
 
 	/* mask our interrupt while resetting the bridge */
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 31f76746741f..7492717c204e 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -944,9 +944,10 @@ void pci_set_acpi_fwnode(struct pci_dev *dev)
 /**
  * pci_dev_acpi_reset - do a function level reset using _RST method
  * @dev: device to reset
- * @probe: check if _RST method is included in the acpi_device context.
+ * @probe: If PCI_RESET_PROBE, check whether _RST method is included
+ *         in the acpi_device context.
  */
-int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
 {
 	acpi_handle handle = ACPI_HANDLE(&dev->dev);
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 5f76d04fa864..08e57ece43f8 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4663,11 +4663,11 @@ EXPORT_SYMBOL_GPL(pcie_flr);
 /**
  * pcie_reset_flr - initiate a PCIe function level reset
  * @dev: device to reset
- * @probe: If set, only check if the device can be reset this way.
+ * @probe: If PCI_RESET_PROBE, only check if the device can be reset this way.
  *
  * Initiate a function level reset on @dev.
  */
-int pcie_reset_flr(struct pci_dev *dev, int probe)
+int pcie_reset_flr(struct pci_dev *dev, bool probe)
 {
 	if (!pcie_has_flr(dev))
 		return -ENOTTY;
@@ -4679,7 +4679,7 @@ int pcie_reset_flr(struct pci_dev *dev, int probe)
 }
 EXPORT_SYMBOL_GPL(pcie_reset_flr);
 
-static int pci_af_flr(struct pci_dev *dev, int probe)
+static int pci_af_flr(struct pci_dev *dev, bool probe)
 {
 	int pos;
 	u8 cap;
@@ -4726,7 +4726,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
 /**
  * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
  * @dev: Device to reset.
- * @probe: If set, only check if the device can be reset this way.
+ * @probe: If PCI_RESET_PROBE, only check if the device can be reset this way.
  *
  * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
  * unset, it will be reinitialized internally when going from PCI_D3hot to
@@ -4738,7 +4738,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
  * by default (i.e. unless the @dev's d3hot_delay field has a different value).
  * Moreover, only devices in D0 can be reset by this function.
  */
-static int pci_pm_reset(struct pci_dev *dev, int probe)
+static int pci_pm_reset(struct pci_dev *dev, bool probe)
 {
 	u16 csr;
 
@@ -4749,7 +4749,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
 		return -ENOTTY;
 
-	if (probe)
+	if (probe == PCI_RESET_PROBE)
 		return 0;
 
 	if (dev->current_state != PCI_D0)
@@ -4998,7 +4998,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
 
-static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
+static int pci_parent_bus_reset(struct pci_dev *dev, bool probe)
 {
 	struct pci_dev *pdev;
 
@@ -5016,7 +5016,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 	return pci_bridge_secondary_bus_reset(dev->bus->self);
 }
 
-static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
+static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe)
 {
 	int rc = -ENOTTY;
 
@@ -5031,7 +5031,7 @@ static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
 	return rc;
 }
 
-static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
+static int pci_dev_reset_slot_function(struct pci_dev *dev, bool probe)
 {
 	if (dev->multifunction || dev->subordinate || !dev->slot ||
 	    dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
@@ -5040,7 +5040,7 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
 	return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
 }
 
-static int pci_reset_bus_function(struct pci_dev *dev, int probe)
+static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
 {
 	int rc;
 
@@ -5203,7 +5203,7 @@ static ssize_t reset_method_store(struct device *dev,
 		if (i < n)
 			continue;
 
-		if (pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
+		if (pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) {
 			pci_warn(pdev, "Unsupported reset method '%s'", name);
 			continue;
 		}
@@ -5222,7 +5222,7 @@ static ssize_t reset_method_store(struct device *dev,
 	if (pdev->reset_methods[0] == 0) {
 		pci_warn(pdev, "All device reset methods disabled by user");
 	} else if ((pdev->reset_methods[0] != 1) &&
-		   !pci_reset_fn_methods[1].reset_fn(pdev, 1)) {
+		   !pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE)) {
 		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
 	}
 	return count;
@@ -5289,7 +5289,7 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 		if (!m)
 			return -ENOTTY;
 
-		rc = pci_reset_fn_methods[m].reset_fn(dev, 0);
+		rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET);
 		if (!rc)
 			return 0;
 		if (rc != -ENOTTY)
@@ -5323,7 +5323,7 @@ void pci_init_reset_methods(struct pci_dev *dev)
 	i = 0;
 
 	for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
-		rc = pci_reset_fn_methods[m].reset_fn(dev, 1);
+		rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_PROBE);
 		if (!rc)
 			dev->reset_methods[i++] = m;
 		else if (rc != -ENOTTY)
@@ -5640,21 +5640,21 @@ static void pci_slot_restore_locked(struct pci_slot *slot)
 	}
 }
 
-static int pci_slot_reset(struct pci_slot *slot, int probe)
+static int pci_slot_reset(struct pci_slot *slot, bool probe)
 {
 	int rc;
 
 	if (!slot || !pci_slot_resetable(slot))
 		return -ENOTTY;
 
-	if (!probe)
+	if (probe != PCI_RESET_PROBE)
 		pci_slot_lock(slot);
 
 	might_sleep();
 
 	rc = pci_reset_hotplug_slot(slot->hotplug, probe);
 
-	if (!probe)
+	if (probe != PCI_RESET_PROBE)
 		pci_slot_unlock(slot);
 
 	return rc;
@@ -5668,7 +5668,7 @@ static int pci_slot_reset(struct pci_slot *slot, int probe)
  */
 int pci_probe_reset_slot(struct pci_slot *slot)
 {
-	return pci_slot_reset(slot, 1);
+	return pci_slot_reset(slot, PCI_RESET_PROBE);
 }
 EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
 
@@ -5691,14 +5691,14 @@ static int __pci_reset_slot(struct pci_slot *slot)
 {
 	int rc;
 
-	rc = pci_slot_reset(slot, 1);
+	rc = pci_slot_reset(slot, PCI_RESET_PROBE);
 	if (rc)
 		return rc;
 
 	if (pci_slot_trylock(slot)) {
 		pci_slot_save_and_disable_locked(slot);
 		might_sleep();
-		rc = pci_reset_hotplug_slot(slot->hotplug, 0);
+		rc = pci_reset_hotplug_slot(slot->hotplug, PCI_RESET_DO_RESET);
 		pci_slot_restore_locked(slot);
 		pci_slot_unlock(slot);
 	} else
@@ -5707,14 +5707,14 @@ static int __pci_reset_slot(struct pci_slot *slot)
 	return rc;
 }
 
-static int pci_bus_reset(struct pci_bus *bus, int probe)
+static int pci_bus_reset(struct pci_bus *bus, bool probe)
 {
 	int ret;
 
 	if (!bus->self || !pci_bus_resetable(bus))
 		return -ENOTTY;
 
-	if (probe)
+	if (probe == PCI_RESET_PROBE)
 		return 0;
 
 	pci_bus_lock(bus);
@@ -5753,14 +5753,14 @@ int pci_bus_error_reset(struct pci_dev *bridge)
 			goto bus_reset;
 
 	list_for_each_entry(slot, &bus->slots, list)
-		if (pci_slot_reset(slot, 0))
+		if (pci_slot_reset(slot, PCI_RESET_DO_RESET))
 			goto bus_reset;
 
 	mutex_unlock(&pci_slot_mutex);
 	return 0;
 bus_reset:
 	mutex_unlock(&pci_slot_mutex);
-	return pci_bus_reset(bridge->subordinate, 0);
+	return pci_bus_reset(bridge->subordinate, PCI_RESET_DO_RESET);
 }
 
 /**
@@ -5771,7 +5771,7 @@ int pci_bus_error_reset(struct pci_dev *bridge)
  */
 int pci_probe_reset_bus(struct pci_bus *bus)
 {
-	return pci_bus_reset(bus, 1);
+	return pci_bus_reset(bus, PCI_RESET_PROBE);
 }
 EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
 
@@ -5785,7 +5785,7 @@ static int __pci_reset_bus(struct pci_bus *bus)
 {
 	int rc;
 
-	rc = pci_bus_reset(bus, 1);
+	rc = pci_bus_reset(bus, PCI_RESET_PROBE);
 	if (rc)
 		return rc;
 
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b13dae3323da..45c93d78f64a 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -604,18 +604,18 @@ static inline int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
 struct pci_dev_reset_methods {
 	u16 vendor;
 	u16 device;
-	int (*reset)(struct pci_dev *dev, int probe);
+	int (*reset)(struct pci_dev *dev, bool probe);
 };
 
 struct pci_reset_fn_method {
-	int (*reset_fn)(struct pci_dev *pdev, int probe);
+	int (*reset_fn)(struct pci_dev *pdev, bool probe);
 	char *name;
 };
 
 #ifdef CONFIG_PCI_QUIRKS
-int pci_dev_specific_reset(struct pci_dev *dev, int probe);
+int pci_dev_specific_reset(struct pci_dev *dev, bool probe);
 #else
-static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
+static inline int pci_dev_specific_reset(struct pci_dev *dev, bool probe)
 {
 	return -ENOTTY;
 }
@@ -704,9 +704,9 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
 int pci_acpi_program_hp_params(struct pci_dev *dev);
 extern const struct attribute_group pci_dev_acpi_attr_group;
 void pci_set_acpi_fwnode(struct pci_dev *dev);
-int pci_dev_acpi_reset(struct pci_dev *dev, int probe);
+int pci_dev_acpi_reset(struct pci_dev *dev, bool probe);
 #else
-static inline int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+static inline int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
 {
 	return -ENOTTY;
 }
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 98077595a73e..cfa7a177500b 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1405,7 +1405,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	}
 
 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
-		rc = pcie_reset_flr(dev, 0);
+		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
 		if (!rc)
 			pci_info(dev, "has been reset\n");
 		else
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 0db5dac3ddce..50c3078bf444 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3669,7 +3669,7 @@ DECLARE_PCI_FIXUP_SUSPEND_LATE(PCI_VENDOR_ID_INTEL,
  * reset a single function if other methods (e.g. FLR, PM D0->D3) are
  * not available.
  */
-static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
+static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, bool probe)
 {
 	/*
 	 * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf
@@ -3691,7 +3691,7 @@ static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
 #define NSDE_PWR_STATE		0xd0100
 #define IGD_OPERATION_TIMEOUT	10000     /* set timeout 10 seconds */
 
-static int reset_ivb_igd(struct pci_dev *dev, int probe)
+static int reset_ivb_igd(struct pci_dev *dev, bool probe)
 {
 	void __iomem *mmio_base;
 	unsigned long timeout;
@@ -3734,7 +3734,7 @@ static int reset_ivb_igd(struct pci_dev *dev, int probe)
 }
 
 /* Device-specific reset method for Chelsio T4-based adapters */
-static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe)
+static int reset_chelsio_generic_dev(struct pci_dev *dev, bool probe)
 {
 	u16 old_command;
 	u16 msix_flags;
@@ -3812,14 +3812,14 @@ static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe)
  *    Chapter 3: NVMe control registers
  *    Chapter 7.3: Reset behavior
  */
-static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
+static int nvme_disable_and_flr(struct pci_dev *dev, bool probe)
 {
 	void __iomem *bar;
 	u16 cmd;
 	u32 cfg;
 
 	if (dev->class != PCI_CLASS_STORAGE_EXPRESS ||
-	    pcie_reset_flr(dev, 1) || !pci_resource_start(dev, 0))
+	    pcie_reset_flr(dev, PCI_RESET_PROBE) || !pci_resource_start(dev, 0))
 		return -ENOTTY;
 
 	if (probe)
@@ -3886,12 +3886,12 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
  * device too soon after FLR.  A 250ms delay after FLR has heuristically
  * proven to produce reliably working results for device assignment cases.
  */
-static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
+static int delay_250ms_after_flr(struct pci_dev *dev, bool probe)
 {
 	if (probe)
-		return pcie_reset_flr(dev, 1);
+		return pcie_reset_flr(dev, PCI_RESET_PROBE);
 
-	pcie_reset_flr(dev, 0);
+	pcie_reset_flr(dev, PCI_RESET_DO_RESET);
 
 	msleep(250);
 
@@ -3906,7 +3906,7 @@ static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
 #define HINIC_OPERATION_TIMEOUT     15000	/* 15 seconds */
 
 /* Device-specific reset method for Huawei Intelligent NIC virtual functions */
-static int reset_hinic_vf_dev(struct pci_dev *pdev, int probe)
+static int reset_hinic_vf_dev(struct pci_dev *pdev, bool probe)
 {
 	unsigned long timeout;
 	void __iomem *bar;
@@ -3983,7 +3983,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
  * because when a host assigns a device to a guest VM, the host may need
  * to reset the device but probably doesn't have a driver for it.
  */
-int pci_dev_specific_reset(struct pci_dev *dev, int probe)
+int pci_dev_specific_reset(struct pci_dev *dev, bool probe)
 {
 	const struct pci_dev_reset_methods *i;
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d3b06bfd8b99..5a9e906b0abf 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -52,6 +52,9 @@
 /* Number of reset methods used in pci_reset_fn_methods array in pci.c */
 #define PCI_NUM_RESET_METHODS 7
 
+#define	PCI_RESET_PROBE		true
+#define PCI_RESET_DO_RESET	false
+
 /*
  * The PCI interface treats multi-function devices as independent
  * devices.  The slot/function address of each device is encoded
@@ -1232,7 +1235,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 			     enum pci_bus_speed *speed,
 			     enum pcie_link_width *width);
 void pcie_print_link_status(struct pci_dev *dev);
-int pcie_reset_flr(struct pci_dev *dev, int probe);
+int pcie_reset_flr(struct pci_dev *dev, bool probe);
 int pcie_flr(struct pci_dev *dev);
 int __pci_reset_function_locked(struct pci_dev *dev);
 int pci_reset_function(struct pci_dev *dev);
diff --git a/include/linux/pci_hotplug.h b/include/linux/pci_hotplug.h
index b482e42d7153..608c012eb8ac 100644
--- a/include/linux/pci_hotplug.h
+++ b/include/linux/pci_hotplug.h
@@ -44,7 +44,7 @@ struct hotplug_slot_ops {
 	int (*get_attention_status)	(struct hotplug_slot *slot, u8 *value);
 	int (*get_latch_status)		(struct hotplug_slot *slot, u8 *value);
 	int (*get_adapter_status)	(struct hotplug_slot *slot, u8 *value);
-	int (*reset_slot)		(struct hotplug_slot *slot, int probe);
+	int (*reset_slot)		(struct hotplug_slot *slot, bool probe);
 };
 
 /**
-- 
2.32.0


^ permalink raw reply related	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 1/9] PCI: Cache PCIe FLR capability
  2021-08-05 16:29 ` [PATCH v15 1/9] PCI: Cache PCIe FLR capability Amey Narkhede
@ 2021-08-09 11:13   ` Raphael Norwitz
  0 siblings, 0 replies; 21+ messages in thread
From: Raphael Norwitz @ 2021-08-09 11:13 UTC (permalink / raw)
  To: Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki

On Thu, Aug 05, 2021 at 09:59:09PM +0530, Amey Narkhede wrote:
> Add a new member called devcap in struct pci_dev for caching the device
> capabilities to avoid reading PCI_EXP_DEVCAP multiple times.
> 
> Refactor pcie_has_flr() to use cached device capabilities.
> 
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>

Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>

> ---
>  drivers/pci/pci.c   | 6 ++----
>  drivers/pci/probe.c | 5 +++--
>  include/linux/pci.h | 1 +
>  3 files changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 452351025a09..1fafd05caa41 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -31,6 +31,7 @@
>  #include <linux/vmalloc.h>
>  #include <asm/dma.h>
>  #include <linux/aer.h>
> +#include <linux/bitfield.h>
>  #include "pci.h"
>  
>  DEFINE_MUTEX(pci_slot_mutex);
> @@ -4620,13 +4621,10 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
>   */
>  bool pcie_has_flr(struct pci_dev *dev)
>  {
> -	u32 cap;
> -
>  	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
>  		return false;
>  
> -	pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap);
> -	return cap & PCI_EXP_DEVCAP_FLR;
> +	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
>  }
>  EXPORT_SYMBOL_GPL(pcie_has_flr);
>  
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 3a62d09b8869..df3f9db6e151 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -19,6 +19,7 @@
>  #include <linux/hypervisor.h>
>  #include <linux/irqdomain.h>
>  #include <linux/pm_runtime.h>
> +#include <linux/bitfield.h>
>  #include "pci.h"
>  
>  #define CARDBUS_LATENCY_TIMER	176	/* secondary latency timer */
> @@ -1497,8 +1498,8 @@ void set_pcie_port_type(struct pci_dev *pdev)
>  	pdev->pcie_cap = pos;
>  	pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, &reg16);
>  	pdev->pcie_flags_reg = reg16;
> -	pci_read_config_word(pdev, pos + PCI_EXP_DEVCAP, &reg16);
> -	pdev->pcie_mpss = reg16 & PCI_EXP_DEVCAP_PAYLOAD;
> +	pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap);
> +	pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap);
>  
>  	parent = pci_upstream_bridge(pdev);
>  	if (!parent)
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index c20211e59a57..697b1f085c7b 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -333,6 +333,7 @@ struct pci_dev {
>  	struct rcec_ea	*rcec_ea;	/* RCEC cached endpoint association */
>  	struct pci_dev  *rcec;          /* Associated RCEC device */
>  #endif
> +	u32		devcap;		/* PCIe device capabilities */
>  	u8		pcie_cap;	/* PCIe capability offset */
>  	u8		msi_cap;	/* MSI capability offset */
>  	u8		msix_cap;	/* MSI-X capability offset */
> -- 
> 2.32.0
> 
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods
  2021-08-05 16:29 ` [PATCH v15 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
@ 2021-08-09 11:15   ` Raphael Norwitz
  0 siblings, 0 replies; 21+ messages in thread
From: Raphael Norwitz @ 2021-08-09 11:15 UTC (permalink / raw)
  To: Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki

On Thu, Aug 05, 2021 at 09:59:10PM +0530, Amey Narkhede wrote:
> Currently there is separate function pcie_has_flr() to probe if PCIe FLR
> is supported by the device which does not match the calling convention
> followed by reset methods which use second function argument to decide
> whether to probe or not. Add new function pcie_reset_flr() that follows
> the calling convention of reset methods.
> 
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>

Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>

> ---
>  drivers/crypto/cavium/nitrox/nitrox_main.c |  4 +--
>  drivers/pci/pci.c                          | 40 +++++++++++++++-------
>  drivers/pci/pcie/aer.c                     | 12 +++----
>  drivers/pci/quirks.c                       |  9 ++---
>  include/linux/pci.h                        |  2 +-
>  5 files changed, 38 insertions(+), 29 deletions(-)
> 
> diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
> index facc8e6bc580..15d6c8452807 100644
> --- a/drivers/crypto/cavium/nitrox/nitrox_main.c
> +++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
> @@ -306,9 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
>  		return -ENOMEM;
>  	}
>  
> -	/* check flr support */
> -	if (pcie_has_flr(pdev))
> -		pcie_flr(pdev);
> +	pcie_reset_flr(pdev, 0);
>  
>  	pci_restore_state(pdev);
>  
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 1fafd05caa41..7d1d9671160b 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4619,22 +4619,20 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
>   * Returns true if the device advertises support for PCIe function level
>   * resets.
>   */
> -bool pcie_has_flr(struct pci_dev *dev)
> +static bool pcie_has_flr(struct pci_dev *dev)
>  {
>  	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
>  		return false;
>  
>  	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
>  }
> -EXPORT_SYMBOL_GPL(pcie_has_flr);
>  
>  /**
>   * pcie_flr - initiate a PCIe function level reset
>   * @dev: device to reset
>   *
> - * Initiate a function level reset on @dev.  The caller should ensure the
> - * device supports FLR before calling this function, e.g. by using the
> - * pcie_has_flr() helper.
> + * Initiate a function level reset unconditionally on @dev without
> + * checking any flags and DEVCAP
>   */
>  int pcie_flr(struct pci_dev *dev)
>  {
> @@ -4657,6 +4655,25 @@ int pcie_flr(struct pci_dev *dev)
>  }
>  EXPORT_SYMBOL_GPL(pcie_flr);
>  
> +/**
> + * pcie_reset_flr - initiate a PCIe function level reset
> + * @dev: device to reset
> + * @probe: If set, only check if the device can be reset this way.
> + *
> + * Initiate a function level reset on @dev.
> + */
> +int pcie_reset_flr(struct pci_dev *dev, int probe)
> +{
> +	if (!pcie_has_flr(dev))
> +		return -ENOTTY;
> +
> +	if (probe)
> +		return 0;
> +
> +	return pcie_flr(dev);
> +}
> +EXPORT_SYMBOL_GPL(pcie_reset_flr);
> +
>  static int pci_af_flr(struct pci_dev *dev, int probe)
>  {
>  	int pos;
> @@ -5137,11 +5154,9 @@ int __pci_reset_function_locked(struct pci_dev *dev)
>  	rc = pci_dev_specific_reset(dev, 0);
>  	if (rc != -ENOTTY)
>  		return rc;
> -	if (pcie_has_flr(dev)) {
> -		rc = pcie_flr(dev);
> -		if (rc != -ENOTTY)
> -			return rc;
> -	}
> +	rc = pcie_reset_flr(dev, 0);
> +	if (rc != -ENOTTY)
> +		return rc;
>  	rc = pci_af_flr(dev, 0);
>  	if (rc != -ENOTTY)
>  		return rc;
> @@ -5172,8 +5187,9 @@ int pci_probe_reset_function(struct pci_dev *dev)
>  	rc = pci_dev_specific_reset(dev, 1);
>  	if (rc != -ENOTTY)
>  		return rc;
> -	if (pcie_has_flr(dev))
> -		return 0;
> +	rc = pcie_reset_flr(dev, 1);
> +	if (rc != -ENOTTY)
> +		return rc;
>  	rc = pci_af_flr(dev, 1);
>  	if (rc != -ENOTTY)
>  		return rc;
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index ec943cee5ecc..98077595a73e 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -1405,13 +1405,11 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
>  	}
>  
>  	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
> -		if (pcie_has_flr(dev)) {
> -			rc = pcie_flr(dev);
> -			pci_info(dev, "has been reset (%d)\n", rc);
> -		} else {
> -			pci_info(dev, "not reset (no FLR support)\n");
> -			rc = -ENOTTY;
> -		}
> +		rc = pcie_reset_flr(dev, 0);
> +		if (!rc)
> +			pci_info(dev, "has been reset\n");
> +		else
> +			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
>  	} else {
>  		rc = pci_bus_error_reset(dev);
>  		pci_info(dev, "%s Port link has been reset (%d)\n",
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index d85914afe65a..b48e7ef8b641 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3819,7 +3819,7 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
>  	u32 cfg;
>  
>  	if (dev->class != PCI_CLASS_STORAGE_EXPRESS ||
> -	    !pcie_has_flr(dev) || !pci_resource_start(dev, 0))
> +	    pcie_reset_flr(dev, 1) || !pci_resource_start(dev, 0))
>  		return -ENOTTY;
>  
>  	if (probe)
> @@ -3888,13 +3888,10 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
>   */
>  static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
>  {
> -	if (!pcie_has_flr(dev))
> -		return -ENOTTY;
> -
>  	if (probe)
> -		return 0;
> +		return pcie_reset_flr(dev, 1);
>  
> -	pcie_flr(dev);
> +	pcie_reset_flr(dev, 0);
>  
>  	msleep(250);
>  
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 697b1f085c7b..aa85e7d3147e 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -1226,7 +1226,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
>  			     enum pci_bus_speed *speed,
>  			     enum pcie_link_width *width);
>  void pcie_print_link_status(struct pci_dev *dev);
> -bool pcie_has_flr(struct pci_dev *dev);
> +int pcie_reset_flr(struct pci_dev *dev, int probe);
>  int pcie_flr(struct pci_dev *dev);
>  int __pci_reset_function_locked(struct pci_dev *dev);
>  int pci_reset_function(struct pci_dev *dev);
> -- 
> 2.32.0
> 
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 3/9] PCI: Add new array for keeping track of ordering of reset methods
  2021-08-05 16:29 ` [PATCH v15 3/9] PCI: Add new array for keeping track of ordering of " Amey Narkhede
@ 2021-08-09 11:18   ` Raphael Norwitz
  0 siblings, 0 replies; 21+ messages in thread
From: Raphael Norwitz @ 2021-08-09 11:18 UTC (permalink / raw)
  To: Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki

On Thu, Aug 05, 2021 at 09:59:11PM +0530, Amey Narkhede wrote:
> Introduce a new array reset_methods in struct pci_dev to keep track of
> reset mechanisms supported by the device and their ordering.
> 
> Also refactor probing and reset functions to take advantage of calling
> convention of reset functions.
> 
> Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>

Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>

> ---
>  drivers/pci/pci.c   | 95 ++++++++++++++++++++++++++-------------------
>  drivers/pci/pci.h   |  8 +++-
>  drivers/pci/probe.c |  5 +--
>  include/linux/pci.h |  7 ++++
>  4 files changed, 71 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 7d1d9671160b..67eab3d29cb3 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -73,6 +73,11 @@ static void pci_dev_d3_sleep(struct pci_dev *dev)
>  		msleep(delay);
>  }
>  
> +bool pci_reset_supported(struct pci_dev *dev)
> +{
> +	return dev->reset_methods[0] != 0;
> +}
> +
>  #ifdef CONFIG_PCI_DOMAINS
>  int pci_domains_supported = 1;
>  #endif
> @@ -5117,6 +5122,16 @@ static void pci_dev_restore(struct pci_dev *dev)
>  		err_handler->reset_done(dev);
>  }
>  
> +/* dev->reset_methods[] is a 0-terminated list of indices into this array */
> +static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
> +	{ },
> +	{ pci_dev_specific_reset, .name = "device_specific" },
> +	{ pcie_reset_flr, .name = "flr" },
> +	{ pci_af_flr, .name = "af_flr" },
> +	{ pci_pm_reset, .name = "pm" },
> +	{ pci_reset_bus_function, .name = "bus" },
> +};
> +
>  /**
>   * __pci_reset_function_locked - reset a PCI device function while holding
>   * the @dev mutex lock.
> @@ -5139,65 +5154,65 @@ static void pci_dev_restore(struct pci_dev *dev)
>   */
>  int __pci_reset_function_locked(struct pci_dev *dev)
>  {
> -	int rc;
> +	int i, m, rc = -ENOTTY;
>  
>  	might_sleep();
>  
>  	/*
> -	 * A reset method returns -ENOTTY if it doesn't support this device
> -	 * and we should try the next method.
> +	 * A reset method returns -ENOTTY if it doesn't support this device and
> +	 * we should try the next method.
>  	 *
> -	 * If it returns 0 (success), we're finished.  If it returns any
> -	 * other error, we're also finished: this indicates that further
> -	 * reset mechanisms might be broken on the device.
> +	 * If it returns 0 (success), we're finished.  If it returns any other
> +	 * error, we're also finished: this indicates that further reset
> +	 * mechanisms might be broken on the device.
>  	 */
> -	rc = pci_dev_specific_reset(dev, 0);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	rc = pcie_reset_flr(dev, 0);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	rc = pci_af_flr(dev, 0);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	rc = pci_pm_reset(dev, 0);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	return pci_reset_bus_function(dev, 0);
> +	for (i = 0; i <  PCI_NUM_RESET_METHODS; i++) {
> +		m = dev->reset_methods[i];
> +		if (!m)
> +			return -ENOTTY;
> +
> +		rc = pci_reset_fn_methods[m].reset_fn(dev, 0);
> +		if (!rc)
> +			return 0;
> +		if (rc != -ENOTTY)
> +			return rc;
> +	}
> +
> +	return -ENOTTY;
>  }
>  EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
>  
>  /**
> - * pci_probe_reset_function - check whether the device can be safely reset
> - * @dev: PCI device to reset
> + * pci_init_reset_methods - check whether device can be safely reset
> + * and store supported reset mechanisms.
> + * @dev: PCI device to check for reset mechanisms
>   *
>   * Some devices allow an individual function to be reset without affecting
> - * other functions in the same device.  The PCI device must be responsive
> - * to PCI config space in order to use this function.
> + * other functions in the same device.  The PCI device must be in D0-D3hot
> + * state.
>   *
> - * Returns 0 if the device function can be reset or negative if the
> - * device doesn't support resetting a single function.
> + * Stores reset mechanisms supported by device in reset_methods byte array
> + * which is a member of struct pci_dev.
>   */
> -int pci_probe_reset_function(struct pci_dev *dev)
> +void pci_init_reset_methods(struct pci_dev *dev)
>  {
> -	int rc;
> +	int m, i, rc;
> +
> +	BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS);
>  
>  	might_sleep();
>  
> -	rc = pci_dev_specific_reset(dev, 1);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	rc = pcie_reset_flr(dev, 1);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	rc = pci_af_flr(dev, 1);
> -	if (rc != -ENOTTY)
> -		return rc;
> -	rc = pci_pm_reset(dev, 1);
> -	if (rc != -ENOTTY)
> -		return rc;
> +	i = 0;
> +
> +	for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
> +		rc = pci_reset_fn_methods[m].reset_fn(dev, 1);
> +		if (!rc)
> +			dev->reset_methods[i++] = m;
> +		else if (rc != -ENOTTY)
> +			break;
> +	}
>  
> -	return pci_reset_bus_function(dev, 1);
> +	dev->reset_methods[i] = 0;
>  }
>  
>  /**
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 37c913bbc6e1..7438953745e0 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -33,7 +33,8 @@ enum pci_mmap_api {
>  int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
>  		  enum pci_mmap_api mmap_api);
>  
> -int pci_probe_reset_function(struct pci_dev *dev);
> +bool pci_reset_supported(struct pci_dev *dev);
> +void pci_init_reset_methods(struct pci_dev *dev);
>  int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
>  int pci_bus_error_reset(struct pci_dev *dev);
>  
> @@ -606,6 +607,11 @@ struct pci_dev_reset_methods {
>  	int (*reset)(struct pci_dev *dev, int probe);
>  };
>  
> +struct pci_reset_fn_method {
> +	int (*reset_fn)(struct pci_dev *pdev, int probe);
> +	char *name;
> +};
> +
>  #ifdef CONFIG_PCI_QUIRKS
>  int pci_dev_specific_reset(struct pci_dev *dev, int probe);
>  #else
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index df3f9db6e151..5d8ad230f7d0 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2405,9 +2405,8 @@ static void pci_init_capabilities(struct pci_dev *dev)
>  	pci_rcec_init(dev);		/* Root Complex Event Collector */
>  
>  	pcie_report_downtraining(dev);
> -
> -	if (pci_probe_reset_function(dev) == 0)
> -		dev->reset_fn = 1;
> +	pci_init_reset_methods(dev);
> +	dev->reset_fn = pci_reset_supported(dev);
>  }
>  
>  /*
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index aa85e7d3147e..d1a9a232d08e 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -49,6 +49,9 @@
>  			       PCI_STATUS_SIG_TARGET_ABORT | \
>  			       PCI_STATUS_PARITY)
>  
> +/* Number of reset methods used in pci_reset_fn_methods array in pci.c */
> +#define PCI_NUM_RESET_METHODS 6
> +
>  /*
>   * The PCI interface treats multi-function devices as independent
>   * devices.  The slot/function address of each device is encoded
> @@ -506,6 +509,10 @@ struct pci_dev {
>  	char		*driver_override; /* Driver name to force a match */
>  
>  	unsigned long	priv_flags;	/* Private flags for the PCI driver */
> +	/*
> +	 * See pci_reset_fn_methods array in pci.c for ordering.
> +	 */
> +	u8 reset_methods[PCI_NUM_RESET_METHODS];	/* Reset methods ordered by priority */
>  };
>  
>  static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
> -- 
> 2.32.0
> 
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 5/9] PCI: Allow userspace to query and set device reset mechanism
  2021-08-05 16:29 ` [PATCH v15 5/9] PCI: Allow userspace to query and set device reset mechanism Amey Narkhede
@ 2021-08-09 11:23   ` Raphael Norwitz
  0 siblings, 0 replies; 21+ messages in thread
From: Raphael Norwitz @ 2021-08-09 11:23 UTC (permalink / raw)
  To: Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki

On Thu, Aug 05, 2021 at 09:59:13PM +0530, Amey Narkhede wrote:
> Add reset_method sysfs attribute to enable user to query and set user
> preferred device reset methods and their ordering.
> 
> Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>

Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>

> ---
>  Documentation/ABI/testing/sysfs-bus-pci |  19 ++++
>  drivers/pci/pci-sysfs.c                 |   1 +
>  drivers/pci/pci.c                       | 117 ++++++++++++++++++++++++
>  drivers/pci/pci.h                       |   2 +
>  4 files changed, 139 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ef00fada2efb..ef66b62bf025 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -121,6 +121,25 @@ Description:
>  		child buses, and re-discover devices removed earlier
>  		from this part of the device tree.
> 
> +What:		/sys/bus/pci/devices/.../reset_method
> +Date:		March 2021
> +Contact:	Amey Narkhede <ameynarkhede03@gmail.com>
> +Description:
> +		Some devices allow an individual function to be reset
> +		without affecting other functions in the same slot.
> +
> +		For devices that have this support, a file named
> +		reset_method will be present in sysfs. Initially reading
> +		this file will give names of the device supported reset
> +		methods and their ordering. After write, this file will
> +		give names and ordering of currently enabled reset methods.
> +		Writing the name or space separated list of names of any of
> +		the device supported reset methods to this file will set
> +		the reset methods and their ordering to be used when
> +		resetting the device. Writing empty string to this file
> +		will disable ability to reset the device and writing
> +		"default" will return to the original value.
> +
>  What:		/sys/bus/pci/devices/.../reset
>  Date:		July 2009
>  Contact:	Michael S. Tsirkin <mst@redhat.com>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 316f70c3e3b4..54ee7193b463 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1491,6 +1491,7 @@ const struct attribute_group *pci_dev_groups[] = {
>  	&pci_dev_config_attr_group,
>  	&pci_dev_rom_attr_group,
>  	&pci_dev_reset_attr_group,
> +	&pci_dev_reset_method_attr_group,
>  	&pci_dev_vpd_attr_group,
>  #ifdef CONFIG_DMI
>  	&pci_dev_smbios_attr_group,
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 8a516e9ca316..53d73770881f 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5132,6 +5132,123 @@ static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
>  	{ pci_reset_bus_function, .name = "bus" },
>  };
> 
> +static ssize_t reset_method_show(struct device *dev,
> +				 struct device_attribute *attr, char *buf)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	ssize_t len = 0;
> +	int i, m;
> +
> +	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> +		m = pdev->reset_methods[i];
> +		if (!m)
> +			break;
> +
> +		len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
> +				     pci_reset_fn_methods[m].name);
> +	}
> +
> +	if (len)
> +		len += sysfs_emit_at(buf, len, "\n");
> +
> +	return len;
> +}
> +
> +static ssize_t reset_method_store(struct device *dev,
> +				  struct device_attribute *attr,
> +				  const char *buf, size_t count)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	int i, m = 0, n = 0;
> +	char *name, *options;
> +
> +	if (count >= (PAGE_SIZE - 1))
> +		return -EINVAL;
> +
> +	if (sysfs_streq(buf, "")) {
> +		goto exit;
> +	}
> +
> +	if (sysfs_streq(buf, "default")) {
> +		pci_init_reset_methods(pdev);
> +		return count;
> +	}
> +
> +	options = kstrndup(buf, count, GFP_KERNEL);
> +	if (!options)
> +		return -ENOMEM;
> +
> +	while ((name = strsep(&options, " ")) != NULL) {
> +		if (sysfs_streq(name, ""))
> +			continue;
> +
> +		name = strim(name);
> +
> +		for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
> +			if (sysfs_streq(name, pci_reset_fn_methods[m].name))
> +				break;
> +		}
> +
> +		if (m == PCI_NUM_RESET_METHODS) {
> +			pci_warn(pdev, "Skip invalid reset method '%s'", name);
> +			continue;
> +		}
> +
> +		for (i = 0; i < n; i++) {
> +			if (pdev->reset_methods[i] == m)
> +				break;
> +		}
> +
> +		if (i < n)
> +			continue;
> +
> +		if (pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
> +			pci_warn(pdev, "Unsupported reset method '%s'", name);
> +			continue;
> +		}
> +
> +		pdev->reset_methods[n++] = m;
> +		BUG_ON(n == PCI_NUM_RESET_METHODS);
> +	}
> +
> +	kfree(options);
> +
> +exit:
> +	/* All the reset methods are invalid */
> +	if (n == 0 && m == PCI_NUM_RESET_METHODS)
> +		return -EINVAL;
> +	pdev->reset_methods[n] = 0;
> +	if (pdev->reset_methods[0] == 0) {
> +		pci_warn(pdev, "All device reset methods disabled by user");
> +	} else if ((pdev->reset_methods[0] != 1) &&
> +		   !pci_reset_fn_methods[1].reset_fn(pdev, 1)) {
> +		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
> +	}
> +	return count;
> +}
> +static DEVICE_ATTR_RW(reset_method);
> +
> +static struct attribute *pci_dev_reset_method_attrs[] = {
> +	&dev_attr_reset_method.attr,
> +	NULL,
> +};
> +
> +static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj,
> +						    struct attribute *a, int n)
> +{
> +	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
> +
> +	if (!pci_reset_supported(pdev))
> +		return 0;
> +
> +	return a->mode;
> +}
> +
> +const struct attribute_group pci_dev_reset_method_attr_group = {
> +	.attrs = pci_dev_reset_method_attrs,
> +	.is_visible = pci_dev_reset_method_attr_is_visible,
> +};
> +
>  /**
>   * __pci_reset_function_locked - reset a PCI device function while holding
>   * the @dev mutex lock.
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 7438953745e0..31458d48eda7 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -714,4 +714,6 @@ static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
>  extern const struct attribute_group aspm_ctrl_attr_group;
>  #endif
> 
> +extern const struct attribute_group pci_dev_reset_method_attr_group;
> +
>  #endif /* DRIVERS_PCI_H */
> --
> 2.32.0
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 0/9] PCI: Expose and manage PCI device reset
  2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
                   ` (8 preceding siblings ...)
  2021-08-05 16:29 ` [PATCH v15 9/9] PCI: Change the type of probe argument in reset functions Amey Narkhede
@ 2021-08-12 13:03 ` Shanker R Donthineni
  9 siblings, 0 replies; 21+ messages in thread
From: Shanker R Donthineni @ 2021-08-12 13:03 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Amey Narkhede, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Sinan Kaya, Len Brown, Rafael J . Wysocki

Hi Bjorn,

On 8/5/21 11:29 AM, Amey Narkhede wrote:
> External email: Use caution opening links or attachments
>
>
> PCI and PCIe devices may support a number of possible reset mechanisms
> for example Function Level Reset (FLR) provided via Advanced Feature or
> PCIe capabilities, Power Management reset, bus reset, or device specific reset.
> Currently the PCI subsystem creates a policy prioritizing these reset methods
> which provides neither visibility nor control to userspace.
>
> Expose the reset methods available per device to userspace, via sysfs
> and allow an administrative user or device owner to have ability to
> manage per device reset method priorities or exclusions.
> This feature aims to allow greater control of a device for use cases
> as device assignment, where specific device or platform issues may
> interact poorly with a given reset method, and for which device specific
> quirks have not been developed.
>
> Changes in v15:
>         - Fix use of uninitialized variable in patch 3/9

We would like to include this feature in the v5.15 release. Could you please look
at the updated patches and provide review feedback?

Thanks,
Shanker Donthineni



^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-08-05 16:29 ` [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
@ 2021-08-13 23:04   ` Bjorn Helgaas
  2021-08-14  3:35     ` Shanker R Donthineni
  0 siblings, 1 reply; 21+ messages in thread
From: Bjorn Helgaas @ 2021-08-13 23:04 UTC (permalink / raw)
  To: Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki, Benjamin Herrenschmidt, Mika Westerberg

[+cc Ben, Mika]

On Thu, Aug 05, 2021 at 09:59:15PM +0530, Amey Narkhede wrote:
> From: Shanker Donthineni <sdonthineni@nvidia.com>
> 
> The pci_dev objects are created through two mechanisms 1) during PCI
> bus scan and 2) from I/O Virtualization. The fwnode in pci_dev object
> is being set at different places depends on the type of firmware used,
> device creation mechanism, and acpi_pci_bridge_d3().
> 
> The software features which have a dependency on ACPI fwnode properties
> and need to be handled before device_add() will not work. One use case,
> the software has to check the existence of _RST method to support ACPI
> based reset method.
> 
> This patch does the two changes in order to provide fwnode consistently.
>  - Set ACPI and OF fwnodes from pci_setup_device().
>  - Remove pci_set_acpi_fwnode() in acpi_pci_bridge_d3().
> 
> After this patch, ACPI/OF firmware properties are visible at the same
> time during the early stage of pci_dev setup. And also call sites should
> be able to use firmware agnostic functions device_property_xxx() for the
> early PCI quirks in the future.
> 
> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
> ---
>  drivers/pci/pci-acpi.c | 1 -
>  drivers/pci/probe.c    | 7 ++++---
>  2 files changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index eaddbf701759..dae021322b3f 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
>  		return false;
>  
>  	/* Assume D3 support if the bridge is power-manageable by ACPI. */
> -	pci_set_acpi_fwnode(dev);
>  	adev = ACPI_COMPANION(&dev->dev);

I *think* the Root Port code farther down in this function is also now
unnecessary:

  acpi_pci_bridge_d3(...)
  {
    ...
    root = pcie_find_root_port(dev);
    adev = ACPI_COMPANION(&root->dev);
    if (root == dev) {
      /*
       * It is possible that the ACPI companion is not yet bound
       * for the root port so look it up manually here.
       */
      if (!adev && !pci_dev_is_added(root))
        adev = acpi_pci_find_companion(&root->dev);
    }

Since we're now setting the ACPI_COMPANION for every pci_dev long
before we get here, I think this could now be simplified to something
like this:

  acpi_pci_bridge_d3(...)
  {
    if (!dev->is_hotplug_bridge)
      return false;

    adev = ACPI_COMPANION(&dev->dev);
    if (adev && acpi_device_power_manageable(adev))
      return true;

    root = pcie_find_root_port(dev);
    if (!root)
      return false;

    adev = ACPI_COMPANION(&root->dev);
    if (!adev)
      return false;

    rc = acpi_dev_get_property(dev, "HotPlugSupportInD3",
                               ACPI_TYPE_INTEGER, &val);
    if (rc < 0)
      return false;

    return val == 1;
  }

acpi_pci_bridge_d3() was added by 26ad34d510a8 ("PCI / ACPI: Whitelist
D3 for more PCIe hotplug ports") [1], so I cc'd Mika in case he has
any comment.

>  	if (adev && acpi_device_power_manageable(adev))
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 379e85037d9b..15a6975d3757 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1789,6 +1789,9 @@ int pci_setup_device(struct pci_dev *dev)
>  	dev->error_state = pci_channel_io_normal;
>  	set_pcie_port_type(dev);
>  
> +	pci_set_of_node(dev);
> +	pci_set_acpi_fwnode(dev);

Is there a reason why you moved pci_set_of_node() from
pci_scan_device() to here?  I think it's a good change; I'm just
curious if you tripped over something that required it.

The pci_set_of_node() was added to pci_scan_device() by 98d9f30c820d
("pci/of: Match PCI devices to OF nodes dynamically") [2], so I cc'd
Ben just in case there's some reason he didn't put it in
pci_setup_device() in the first place.

>  	pci_dev_assign_slot(dev);
>  
>  	/*
> @@ -1924,6 +1927,7 @@ int pci_setup_device(struct pci_dev *dev)
>  	default:				    /* unknown header */
>  		pci_err(dev, "unknown header type %02x, ignoring device\n",
>  			dev->hdr_type);
> +		pci_release_of_node(dev);
>  		return -EIO;
>  
>  	bad:
> @@ -2351,10 +2355,7 @@ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn)
>  	dev->vendor = l & 0xffff;
>  	dev->device = (l >> 16) & 0xffff;
>  
> -	pci_set_of_node(dev);
> -
>  	if (pci_setup_device(dev)) {
> -		pci_release_of_node(dev);
>  		pci_bus_put(dev->bus);
>  		kfree(dev);
>  		return NULL;

[1] https://git.kernel.org/linus/26ad34d510a8
[2] https://git.kernel.org/linus/98d9f30c820d

^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-08-13 23:04   ` Bjorn Helgaas
@ 2021-08-14  3:35     ` Shanker R Donthineni
  2021-08-14  4:10       ` Bjorn Helgaas
  0 siblings, 1 reply; 21+ messages in thread
From: Shanker R Donthineni @ 2021-08-14  3:35 UTC (permalink / raw)
  To: Bjorn Helgaas, Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Sinan Kaya, Len Brown, Rafael J . Wysocki,
	Benjamin Herrenschmidt, Mika Westerberg

Hi Bjorn,

On 8/13/21 6:04 PM, Bjorn Helgaas wrote:
> External email: Use caution opening links or attachments
>
>
> [+cc Ben, Mika]
>
> On Thu, Aug 05, 2021 at 09:59:15PM +0530, Amey Narkhede wrote:
>> From: Shanker Donthineni <sdonthineni@nvidia.com>
>>
>> The pci_dev objects are created through two mechanisms 1) during PCI
>> bus scan and 2) from I/O Virtualization. The fwnode in pci_dev object
>> is being set at different places depends on the type of firmware used,
>> device creation mechanism, and acpi_pci_bridge_d3().
>>
>> The software features which have a dependency on ACPI fwnode properties
>> and need to be handled before device_add() will not work. One use case,
>> the software has to check the existence of _RST method to support ACPI
>> based reset method.
>>
>> This patch does the two changes in order to provide fwnode consistently.
>>  - Set ACPI and OF fwnodes from pci_setup_device().
>>  - Remove pci_set_acpi_fwnode() in acpi_pci_bridge_d3().
>>
>> After this patch, ACPI/OF firmware properties are visible at the same
>> time during the early stage of pci_dev setup. And also call sites should
>> be able to use firmware agnostic functions device_property_xxx() for the
>> early PCI quirks in the future.
>>
>> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
>> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
>> ---
>>  drivers/pci/pci-acpi.c | 1 -
>>  drivers/pci/probe.c    | 7 ++++---
>>  2 files changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
>> index eaddbf701759..dae021322b3f 100644
>> --- a/drivers/pci/pci-acpi.c
>> +++ b/drivers/pci/pci-acpi.c
>> @@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
>>               return false;
>>
>>       /* Assume D3 support if the bridge is power-manageable by ACPI. */
>> -     pci_set_acpi_fwnode(dev);
>>       adev = ACPI_COMPANION(&dev->dev);
> I *think* the Root Port code farther down in this function is also now
> unnecessary:
>
>   acpi_pci_bridge_d3(...)
>   {
>     ...
>     root = pcie_find_root_port(dev);
>     adev = ACPI_COMPANION(&root->dev);
>     if (root == dev) {
>       /*
>        * It is possible that the ACPI companion is not yet bound
>        * for the root port so look it up manually here.
>        */
>       if (!adev && !pci_dev_is_added(root))
>         adev = acpi_pci_find_companion(&root->dev);
>     }
>
> Since we're now setting the ACPI_COMPANION for every pci_dev long
> before we get here, I think this could now be simplified to something
> like this:
>
>   acpi_pci_bridge_d3(...)
>   {
>     if (!dev->is_hotplug_bridge)
>       return false;
>
>     adev = ACPI_COMPANION(&dev->dev);
>     if (adev && acpi_device_power_manageable(adev))
>       return true;
>
>     root = pcie_find_root_port(dev);
>     if (!root)
>       return false;
>
>     adev = ACPI_COMPANION(&root->dev);
>     if (!adev)
>       return false;
>
>     rc = acpi_dev_get_property(dev, "HotPlugSupportInD3",
>                                ACPI_TYPE_INTEGER, &val);
>     if (rc < 0)
>       return false;
>
>     return val == 1;
>   }

Agree, thanks for your suggestion. Yes, it can be simplified too.
Can I do something like this using the unified device property API?

static bool acpi_pci_bridge_d3(struct pci_dev *dev)
{
        struct acpi_device *adev;
        struct pci_dev *root;
        u8 val;

        if (!dev->is_hotplug_bridge)
                return false;

        adev = ACPI_COMPANION(&dev->dev);
        if (adev && acpi_device_power_manageable(adev))
                return true;

        root = pcie_find_root_port(dev);
        if (!root)
                return false;

        if (device_property_read_u8(&root->dev, "HotPlugSupportInD3", &val))
                return false;

        return val == 1;
}

> acpi_pci_bridge_d3() was added by 26ad34d510a8 ("PCI / ACPI: Whitelist
> D3 for more PCIe hotplug ports") [1], so I cc'd Mika in case he has
> any comment.
>
>>       if (adev && acpi_device_power_manageable(adev))
>> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
>> index 379e85037d9b..15a6975d3757 100644
>> --- a/drivers/pci/probe.c
>> +++ b/drivers/pci/probe.c
>> @@ -1789,6 +1789,9 @@ int pci_setup_device(struct pci_dev *dev)
>>       dev->error_state = pci_channel_io_normal;
>>       set_pcie_port_type(dev);
>>
>> +     pci_set_of_node(dev);
>> +     pci_set_acpi_fwnode(dev);
> Is there a reason why you moved pci_set_of_node() from
> pci_scan_device() to here?  I think it's a good change; I'm just
> curious if you tripped over something that required it.

There is no specific reason and not required but setting both the fwnodes
at the same time improves the code readability and provides consistent
device properties for callers.

> The pci_set_of_node() was added to pci_scan_device() by 98d9f30c820d
> ("pci/of: Match PCI devices to OF nodes dynamically") [2], so I cc'd
> Ben just in case there's some reason he didn't put it in
> pci_setup_device() in the first place.
>

Thanks,
Shanker Donthineni


^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-08-14  3:35     ` Shanker R Donthineni
@ 2021-08-14  4:10       ` Bjorn Helgaas
  2021-08-14 16:16         ` Shanker R Donthineni
  0 siblings, 1 reply; 21+ messages in thread
From: Bjorn Helgaas @ 2021-08-14  4:10 UTC (permalink / raw)
  To: Shanker R Donthineni
  Cc: Amey Narkhede, Bjorn Helgaas, alex.williamson, Raphael Norwitz,
	linux-pci, linux-kernel, kw, Sinan Kaya, Len Brown,
	Rafael J . Wysocki, Benjamin Herrenschmidt, Mika Westerberg

On Fri, Aug 13, 2021 at 10:35:46PM -0500, Shanker R Donthineni wrote:
> Hi Bjorn,
> 
> On 8/13/21 6:04 PM, Bjorn Helgaas wrote:
> > External email: Use caution opening links or attachments
> >
> >
> > [+cc Ben, Mika]
> >
> > On Thu, Aug 05, 2021 at 09:59:15PM +0530, Amey Narkhede wrote:
> >> From: Shanker Donthineni <sdonthineni@nvidia.com>
> >>
> >> The pci_dev objects are created through two mechanisms 1) during PCI
> >> bus scan and 2) from I/O Virtualization. The fwnode in pci_dev object
> >> is being set at different places depends on the type of firmware used,
> >> device creation mechanism, and acpi_pci_bridge_d3().
> >>
> >> The software features which have a dependency on ACPI fwnode properties
> >> and need to be handled before device_add() will not work. One use case,
> >> the software has to check the existence of _RST method to support ACPI
> >> based reset method.
> >>
> >> This patch does the two changes in order to provide fwnode consistently.
> >>  - Set ACPI and OF fwnodes from pci_setup_device().
> >>  - Remove pci_set_acpi_fwnode() in acpi_pci_bridge_d3().
> >>
> >> After this patch, ACPI/OF firmware properties are visible at the same
> >> time during the early stage of pci_dev setup. And also call sites should
> >> be able to use firmware agnostic functions device_property_xxx() for the
> >> early PCI quirks in the future.
> >>
> >> Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com>
> >> Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
> >> ---
> >>  drivers/pci/pci-acpi.c | 1 -
> >>  drivers/pci/probe.c    | 7 ++++---
> >>  2 files changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> >> index eaddbf701759..dae021322b3f 100644
> >> --- a/drivers/pci/pci-acpi.c
> >> +++ b/drivers/pci/pci-acpi.c
> >> @@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> >>               return false;
> >>
> >>       /* Assume D3 support if the bridge is power-manageable by ACPI. */
> >> -     pci_set_acpi_fwnode(dev);
> >>       adev = ACPI_COMPANION(&dev->dev);
> > I *think* the Root Port code farther down in this function is also now
> > unnecessary:
> >
> >   acpi_pci_bridge_d3(...)
> >   {
> >     ...
> >     root = pcie_find_root_port(dev);
> >     adev = ACPI_COMPANION(&root->dev);
> >     if (root == dev) {
> >       /*
> >        * It is possible that the ACPI companion is not yet bound
> >        * for the root port so look it up manually here.
> >        */
> >       if (!adev && !pci_dev_is_added(root))
> >         adev = acpi_pci_find_companion(&root->dev);
> >     }
> >
> > Since we're now setting the ACPI_COMPANION for every pci_dev long
> > before we get here, I think this could now be simplified to something
> > like this:
> >
> >   acpi_pci_bridge_d3(...)
> >   {
> >     if (!dev->is_hotplug_bridge)
> >       return false;
> >
> >     adev = ACPI_COMPANION(&dev->dev);
> >     if (adev && acpi_device_power_manageable(adev))
> >       return true;
> >
> >     root = pcie_find_root_port(dev);
> >     if (!root)
> >       return false;
> >
> >     adev = ACPI_COMPANION(&root->dev);
> >     if (!adev)
> >       return false;
> >
> >     rc = acpi_dev_get_property(dev, "HotPlugSupportInD3",
> >                                ACPI_TYPE_INTEGER, &val);
> >     if (rc < 0)
> >       return false;
> >
> >     return val == 1;
> >   }
> 
> Agree, thanks for your suggestion. Yes, it can be simplified too.
> Can I do something like this using the unified device property API?
> 
> static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> {
>         struct acpi_device *adev;
>         struct pci_dev *root;
>         u8 val;
> 
>         if (!dev->is_hotplug_bridge)
>                 return false;
> 
>         adev = ACPI_COMPANION(&dev->dev);
>         if (adev && acpi_device_power_manageable(adev))
>                 return true;
> 
>         root = pcie_find_root_port(dev);
>         if (!root)
>                 return false;
> 
>         if (device_property_read_u8(&root->dev, "HotPlugSupportInD3", &val))
>                 return false;

I guess that might be OK.

TBH I don't really like the device_property_read_u8() thing because
(1) we know this is an ACPI property and I don't see a reason to use
an "generic" interface that doesn't buy us anything, and (2) the
connection to the source of the data (a _DSD method) is really, really
hard to find.

Admittedly, it's still pretty hard to connect acpi_dev_get_property()
with "_DSD".  The only real clue is the comment about "Look for a
special _DSD property ..."

>         return val == 1;
> }
> 
> > acpi_pci_bridge_d3() was added by 26ad34d510a8 ("PCI / ACPI: Whitelist
> > D3 for more PCIe hotplug ports") [1], so I cc'd Mika in case he has
> > any comment.
> >
> >>       if (adev && acpi_device_power_manageable(adev))
> >> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> >> index 379e85037d9b..15a6975d3757 100644
> >> --- a/drivers/pci/probe.c
> >> +++ b/drivers/pci/probe.c
> >> @@ -1789,6 +1789,9 @@ int pci_setup_device(struct pci_dev *dev)
> >>       dev->error_state = pci_channel_io_normal;
> >>       set_pcie_port_type(dev);
> >>
> >> +     pci_set_of_node(dev);
> >> +     pci_set_acpi_fwnode(dev);
> > Is there a reason why you moved pci_set_of_node() from
> > pci_scan_device() to here?  I think it's a good change; I'm just
> > curious if you tripped over something that required it.
> 
> There is no specific reason and not required but setting both the fwnodes
> at the same time improves the code readability and provides consistent
> device properties for callers.

Sounds good.

Bjorn

^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 9/9] PCI: Change the type of probe argument in reset functions
  2021-08-05 16:29 ` [PATCH v15 9/9] PCI: Change the type of probe argument in reset functions Amey Narkhede
@ 2021-08-14 14:05   ` Shanker R Donthineni
  0 siblings, 0 replies; 21+ messages in thread
From: Shanker R Donthineni @ 2021-08-14 14:05 UTC (permalink / raw)
  To: Amey Narkhede, Bjorn Helgaas
  Cc: alex.williamson, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Sinan Kaya, Len Brown, Rafael J . Wysocki

Hi Amey,

On 8/5/21 11:29 AM, Amey Narkhede wrote:
> External email: Use caution opening links or attachments
>
>
> Change the type of probe argument in functions which implement reset
> methods from int to bool to make the context and intent clear.
>
> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
> Suggested-by: Krzysztof Wilczyński <kw@linux.com>
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> ---
>  drivers/crypto/cavium/nitrox/nitrox_main.c    |  2 +-
>  .../ethernet/cavium/liquidio/lio_vf_main.c    |  2 +-
>  drivers/pci/hotplug/pciehp.h                  |  2 +-
>  drivers/pci/hotplug/pciehp_hpc.c              |  2 +-
>  drivers/pci/hotplug/pnv_php.c                 |  4 +-
>  drivers/pci/pci-acpi.c                        |  5 +-
>  drivers/pci/pci.c                             | 52 +++++++++----------
>  drivers/pci/pci.h                             | 12 ++---
>  drivers/pci/pcie/aer.c                        |  2 +-
>  drivers/pci/quirks.c                          | 20 +++----
>  include/linux/pci.h                           |  5 +-
>  include/linux/pci_hotplug.h                   |  2 +-
>  12 files changed, 57 insertions(+), 53 deletions(-)
>
> diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
> index 15d6c8452807..f97fa8e997b5 100644
> --- a/drivers/crypto/cavium/nitrox/nitrox_main.c
> +++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
> @@ -306,7 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
>                 return -ENOMEM;
>         }
>
> -       pcie_reset_flr(pdev, 0);
> +       pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
>
>         pci_restore_state(pdev);
>
> diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> index 336d149ee2e2..6e666be6907a 100644
> --- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> +++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> @@ -526,7 +526,7 @@ static void octeon_destroy_resources(struct octeon_device *oct)
>                         oct->irq_name_storage = NULL;
>                 }
>                 /* Soft reset the octeon device before exiting */
> -               if (!pcie_reset_flr(oct->pci_dev, 1))
> +               if (!pcie_reset_flr(oct->pci_dev, PCI_RESET_PROBE))
>                         octeon_pci_flr(oct);
>                 else
>                         cn23xx_vf_ask_pf_to_do_flr(oct);
> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
> index 4fd200d8b0a9..23d6d6813edf 100644
> --- a/drivers/pci/hotplug/pciehp.h
> +++ b/drivers/pci/hotplug/pciehp.h
> @@ -181,7 +181,7 @@ void pciehp_release_ctrl(struct controller *ctrl);
>
>  int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
>  int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
> -int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
> +int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe);
>  int pciehp_get_attention_status(struct hotplug_slot *hotplug_slot, u8 *status);
>  int pciehp_set_raw_indicator_status(struct hotplug_slot *h_slot, u8 status);
>  int pciehp_get_raw_indicator_status(struct hotplug_slot *h_slot, u8 *status);
> diff --git a/drivers/pci/hotplug/pciehp_hpc.c b/drivers/pci/hotplug/pciehp_hpc.c
> index fb3840e222ad..d9f782b2e203 100644
> --- a/drivers/pci/hotplug/pciehp_hpc.c
> +++ b/drivers/pci/hotplug/pciehp_hpc.c
> @@ -834,7 +834,7 @@ void pcie_disable_interrupt(struct controller *ctrl)
>   * momentarily, if we see that they could interfere. Also, clear any spurious
>   * events after.
>   */
> -int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe)
> +int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool probe)
>  {
>         struct controller *ctrl = to_ctrl(hotplug_slot);
>         struct pci_dev *pdev = ctrl_dev(ctrl);
> diff --git a/drivers/pci/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
> index 04565162a449..4c17a5dc26cf 100644
> --- a/drivers/pci/hotplug/pnv_php.c
> +++ b/drivers/pci/hotplug/pnv_php.c
> @@ -526,7 +526,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
>         return 0;
>  }
>
> -static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
> +static int pnv_php_reset_slot(struct hotplug_slot *slot, bool probe)
>  {
>         struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
>         struct pci_dev *bridge = php_slot->pdev;
> @@ -537,7 +537,7 @@ static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
>          * which don't have a bridge. Only claim to support
>          * reset_slot() if we have a bridge device (for now...)
>          */
> -       if (probe)
> +       if (probe == PCI_RESET_PROBE)
Some places you're using 'if (probe)' to check PROBE condition. It would be better
to keep code changes consistent. The variable name 'probe' itself indicates whether
a caller requesting a probe or reset. This change is unnecessary.

>                 return !bridge;
>
>         /* mask our interrupt while resetting the bridge */
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index 31f76746741f..7492717c204e 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -944,9 +944,10 @@ void pci_set_acpi_fwnode(struct pci_dev *dev)
>  /**
>   * pci_dev_acpi_reset - do a function level reset using _RST method
>   * @dev: device to reset
> - * @probe: check if _RST method is included in the acpi_device context.
> + * @probe: If PCI_RESET_PROBE, check whether _RST method is included
> + *         in the acpi_device context.
>   */
> -int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
> +int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
>  {
>         acpi_handle handle = ACPI_HANDLE(&dev->dev);
>
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 5f76d04fa864..08e57ece43f8 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4663,11 +4663,11 @@ EXPORT_SYMBOL_GPL(pcie_flr);
>  /**
>   * pcie_reset_flr - initiate a PCIe function level reset
>   * @dev: device to reset
> - * @probe: If set, only check if the device can be reset this way.
> + * @probe: If PCI_RESET_PROBE, only check if the device can be reset this way.
>   *
>   * Initiate a function level reset on @dev.
>   */
> -int pcie_reset_flr(struct pci_dev *dev, int probe)
> +int pcie_reset_flr(struct pci_dev *dev, bool probe)
>  {
>         if (!pcie_has_flr(dev))
>                 return -ENOTTY;
> @@ -4679,7 +4679,7 @@ int pcie_reset_flr(struct pci_dev *dev, int probe)
>  }
>  EXPORT_SYMBOL_GPL(pcie_reset_flr);
>
> -static int pci_af_flr(struct pci_dev *dev, int probe)
> +static int pci_af_flr(struct pci_dev *dev, bool probe)
>  {
>         int pos;
>         u8 cap;
> @@ -4726,7 +4726,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
>  /**
>   * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
>   * @dev: Device to reset.
> - * @probe: If set, only check if the device can be reset this way.
> + * @probe: If PCI_RESET_PROBE, only check if the device can be reset this way.
>   *
>   * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is
>   * unset, it will be reinitialized internally when going from PCI_D3hot to
> @@ -4738,7 +4738,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
>   * by default (i.e. unless the @dev's d3hot_delay field has a different value).
>   * Moreover, only devices in D0 can be reset by this function.
>   */
> -static int pci_pm_reset(struct pci_dev *dev, int probe)
> +static int pci_pm_reset(struct pci_dev *dev, bool probe)
>  {
>         u16 csr;
>
> @@ -4749,7 +4749,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
>         if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
>                 return -ENOTTY;
>
> -       if (probe)
> +       if (probe == PCI_RESET_PROBE)

Same here.

>                 return 0;
>
>         if (dev->current_state != PCI_D0)
> @@ -4998,7 +4998,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
>  }
>  EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
>
> -static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
> +static int pci_parent_bus_reset(struct pci_dev *dev, bool probe)
>  {
>         struct pci_dev *pdev;
>
> @@ -5016,7 +5016,7 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
>         return pci_bridge_secondary_bus_reset(dev->bus->self);
>  }
>
> -static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
> +static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe)
>  {
>         int rc = -ENOTTY;
>
> @@ -5031,7 +5031,7 @@ static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
>         return rc;
>  }
>
> -static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
> +static int pci_dev_reset_slot_function(struct pci_dev *dev, bool probe)
>  {
>         if (dev->multifunction || dev->subordinate || !dev->slot ||
>             dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
> @@ -5040,7 +5040,7 @@ static int pci_dev_reset_slot_function(struct pci_dev *dev, int probe)
>         return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
>  }
>
> -static int pci_reset_bus_function(struct pci_dev *dev, int probe)
> +static int pci_reset_bus_function(struct pci_dev *dev, bool probe)
>  {
>         int rc;
>
> @@ -5203,7 +5203,7 @@ static ssize_t reset_method_store(struct device *dev,
>                 if (i < n)
>                         continue;
>
> -               if (pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
> +               if (pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) {
>                         pci_warn(pdev, "Unsupported reset method '%s'", name);
>                         continue;
>                 }
> @@ -5222,7 +5222,7 @@ static ssize_t reset_method_store(struct device *dev,
>         if (pdev->reset_methods[0] == 0) {
>                 pci_warn(pdev, "All device reset methods disabled by user");
>         } else if ((pdev->reset_methods[0] != 1) &&
> -                  !pci_reset_fn_methods[1].reset_fn(pdev, 1)) {
> +                  !pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE)) {
>                 pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
>         }
>         return count;
> @@ -5289,7 +5289,7 @@ int __pci_reset_function_locked(struct pci_dev *dev)
>                 if (!m)
>                         return -ENOTTY;
>
> -               rc = pci_reset_fn_methods[m].reset_fn(dev, 0);
> +               rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET);
>                 if (!rc)
>                         return 0;
>                 if (rc != -ENOTTY)
> @@ -5323,7 +5323,7 @@ void pci_init_reset_methods(struct pci_dev *dev)
>         i = 0;
>
>         for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
> -               rc = pci_reset_fn_methods[m].reset_fn(dev, 1);
> +               rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_PROBE);
>                 if (!rc)
>                         dev->reset_methods[i++] = m;
>                 else if (rc != -ENOTTY)
> @@ -5640,21 +5640,21 @@ static void pci_slot_restore_locked(struct pci_slot *slot)
>         }
>  }
>
> -static int pci_slot_reset(struct pci_slot *slot, int probe)
> +static int pci_slot_reset(struct pci_slot *slot, bool probe)
>  {
>         int rc;
>
>         if (!slot || !pci_slot_resetable(slot))
>                 return -ENOTTY;
>
> -       if (!probe)
> +       if (probe != PCI_RESET_PROBE)
The existing condition still works.

>                 pci_slot_lock(slot);
>
>         might_sleep();
>
>         rc = pci_reset_hotplug_slot(slot->hotplug, probe);
>
> -       if (!probe)
> +       if (probe != PCI_RESET_PROBE)
>                 pci_slot_unlock(slot);
Same here.
>         return rc;
> @@ -5668,7 +5668,7 @@ static int pci_slot_reset(struct pci_slot *slot, int probe)
>   */
>  int pci_probe_reset_slot(struct pci_slot *slot)
>  {
> -       return pci_slot_reset(slot, 1);
> +       return pci_slot_reset(slot, PCI_RESET_PROBE);
>  }
>  EXPORT_SYMBOL_GPL(pci_probe_reset_slot);
>
> @@ -5691,14 +5691,14 @@ static int __pci_reset_slot(struct pci_slot *slot)
>  {
>         int rc;
>
> -       rc = pci_slot_reset(slot, 1);
> +       rc = pci_slot_reset(slot, PCI_RESET_PROBE);
>         if (rc)
>                 return rc;
>
>         if (pci_slot_trylock(slot)) {
>                 pci_slot_save_and_disable_locked(slot);
>                 might_sleep();
> -               rc = pci_reset_hotplug_slot(slot->hotplug, 0);
> +               rc = pci_reset_hotplug_slot(slot->hotplug, PCI_RESET_DO_RESET);
>                 pci_slot_restore_locked(slot);
>                 pci_slot_unlock(slot);
>         } else
> @@ -5707,14 +5707,14 @@ static int __pci_reset_slot(struct pci_slot *slot)
>         return rc;
>  }
>
> -static int pci_bus_reset(struct pci_bus *bus, int probe)
> +static int pci_bus_reset(struct pci_bus *bus, bool probe)
>  {
>         int ret;
>
>         if (!bus->self || !pci_bus_resetable(bus))
>                 return -ENOTTY;
>
> -       if (probe)
> +       if (probe == PCI_RESET_PROBE)

Same here.

>                 return 0;
>
>         pci_bus_lock(bus);
> @@ -5753,14 +5753,14 @@ int pci_bus_error_reset(struct pci_dev *bridge)
>                         goto bus_reset;
>
>         list_for_each_entry(slot, &bus->slots, list)
> -               if (pci_slot_reset(slot, 0))
> +               if (pci_slot_reset(slot, PCI_RESET_DO_RESET))
>                         goto bus_reset;
>
>         mutex_unlock(&pci_slot_mutex);
>         return 0;
>  bus_reset:
>         mutex_unlock(&pci_slot_mutex);
> -       return pci_bus_reset(bridge->subordinate, 0);
> +       return pci_bus_reset(bridge->subordinate, PCI_RESET_DO_RESET);
>  }
>
>  /**
> @@ -5771,7 +5771,7 @@ int pci_bus_error_reset(struct pci_dev *bridge)
>   */
>  int pci_probe_reset_bus(struct pci_bus *bus)
>  {
> -       return pci_bus_reset(bus, 1);
> +       return pci_bus_reset(bus, PCI_RESET_PROBE);
>  }
>  EXPORT_SYMBOL_GPL(pci_probe_reset_bus);
>
> @@ -5785,7 +5785,7 @@ static int __pci_reset_bus(struct pci_bus *bus)
>  {
>         int rc;
>
> -       rc = pci_bus_reset(bus, 1);
> +       rc = pci_bus_reset(bus, PCI_RESET_PROBE);
>         if (rc)
>                 return rc;
>
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index b13dae3323da..45c93d78f64a 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -604,18 +604,18 @@ static inline int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
>  struct pci_dev_reset_methods {
>         u16 vendor;
>         u16 device;
> -       int (*reset)(struct pci_dev *dev, int probe);
> +       int (*reset)(struct pci_dev *dev, bool probe);
>  };
>
>  struct pci_reset_fn_method {
> -       int (*reset_fn)(struct pci_dev *pdev, int probe);
> +       int (*reset_fn)(struct pci_dev *pdev, bool probe);
>         char *name;
>  };
>
>  #ifdef CONFIG_PCI_QUIRKS
> -int pci_dev_specific_reset(struct pci_dev *dev, int probe);
> +int pci_dev_specific_reset(struct pci_dev *dev, bool probe);
>  #else
> -static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
> +static inline int pci_dev_specific_reset(struct pci_dev *dev, bool probe)
>  {
>         return -ENOTTY;
>  }
> @@ -704,9 +704,9 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
>  int pci_acpi_program_hp_params(struct pci_dev *dev);
>  extern const struct attribute_group pci_dev_acpi_attr_group;
>  void pci_set_acpi_fwnode(struct pci_dev *dev);
> -int pci_dev_acpi_reset(struct pci_dev *dev, int probe);
> +int pci_dev_acpi_reset(struct pci_dev *dev, bool probe);
>  #else
> -static inline int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
> +static inline int pci_dev_acpi_reset(struct pci_dev *dev, bool probe)
>  {
>         return -ENOTTY;
>  }
> diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
> index 98077595a73e..cfa7a177500b 100644
> --- a/drivers/pci/pcie/aer.c
> +++ b/drivers/pci/pcie/aer.c
> @@ -1405,7 +1405,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
>         }
>
>         if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
> -               rc = pcie_reset_flr(dev, 0);
> +               rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
>                 if (!rc)
>                         pci_info(dev, "has been reset\n");
>                 else
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 0db5dac3ddce..50c3078bf444 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c
> @@ -3669,7 +3669,7 @@ DECLARE_PCI_FIXUP_SUSPEND_LATE(PCI_VENDOR_ID_INTEL,
>   * reset a single function if other methods (e.g. FLR, PM D0->D3) are
>   * not available.
>   */
> -static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
> +static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, bool probe)
>  {
>         /*
>          * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf
> @@ -3691,7 +3691,7 @@ static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
>  #define NSDE_PWR_STATE         0xd0100
>  #define IGD_OPERATION_TIMEOUT  10000     /* set timeout 10 seconds */
>
> -static int reset_ivb_igd(struct pci_dev *dev, int probe)
> +static int reset_ivb_igd(struct pci_dev *dev, bool probe)
>  {
>         void __iomem *mmio_base;
>         unsigned long timeout;
> @@ -3734,7 +3734,7 @@ static int reset_ivb_igd(struct pci_dev *dev, int probe)
>  }
>
>  /* Device-specific reset method for Chelsio T4-based adapters */
> -static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe)
> +static int reset_chelsio_generic_dev(struct pci_dev *dev, bool probe)
>  {
>         u16 old_command;
>         u16 msix_flags;
> @@ -3812,14 +3812,14 @@ static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe)
>   *    Chapter 3: NVMe control registers
>   *    Chapter 7.3: Reset behavior
>   */
> -static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
> +static int nvme_disable_and_flr(struct pci_dev *dev, bool probe)
>  {
>         void __iomem *bar;
>         u16 cmd;
>         u32 cfg;
>
>         if (dev->class != PCI_CLASS_STORAGE_EXPRESS ||
> -           pcie_reset_flr(dev, 1) || !pci_resource_start(dev, 0))
> +           pcie_reset_flr(dev, PCI_RESET_PROBE) || !pci_resource_start(dev, 0))
>                 return -ENOTTY;
>
>         if (probe)
> @@ -3886,12 +3886,12 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
>   * device too soon after FLR.  A 250ms delay after FLR has heuristically
>   * proven to produce reliably working results for device assignment cases.
>   */
> -static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
> +static int delay_250ms_after_flr(struct pci_dev *dev, bool probe)
>  {
>         if (probe)
> -               return pcie_reset_flr(dev, 1);
> +               return pcie_reset_flr(dev, PCI_RESET_PROBE);
>
> -       pcie_reset_flr(dev, 0);
> +       pcie_reset_flr(dev, PCI_RESET_DO_RESET);
>
>         msleep(250);
>
> @@ -3906,7 +3906,7 @@ static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
>  #define HINIC_OPERATION_TIMEOUT     15000      /* 15 seconds */
>
>  /* Device-specific reset method for Huawei Intelligent NIC virtual functions */
> -static int reset_hinic_vf_dev(struct pci_dev *pdev, int probe)
> +static int reset_hinic_vf_dev(struct pci_dev *pdev, bool probe)
>  {
>         unsigned long timeout;
>         void __iomem *bar;
> @@ -3983,7 +3983,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
>   * because when a host assigns a device to a guest VM, the host may need
>   * to reset the device but probably doesn't have a driver for it.
>   */
> -int pci_dev_specific_reset(struct pci_dev *dev, int probe)
> +int pci_dev_specific_reset(struct pci_dev *dev, bool probe)
>  {
>         const struct pci_dev_reset_methods *i;
>
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index d3b06bfd8b99..5a9e906b0abf 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -52,6 +52,9 @@
>  /* Number of reset methods used in pci_reset_fn_methods array in pci.c */
>  #define PCI_NUM_RESET_METHODS 7
>
> +#define        PCI_RESET_PROBE         true
> +#define PCI_RESET_DO_RESET     false
> +
>  /*
>   * The PCI interface treats multi-function devices as independent
>   * devices.  The slot/function address of each device is encoded
> @@ -1232,7 +1235,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
>                              enum pci_bus_speed *speed,
>                              enum pcie_link_width *width);
>  void pcie_print_link_status(struct pci_dev *dev);
> -int pcie_reset_flr(struct pci_dev *dev, int probe);
> +int pcie_reset_flr(struct pci_dev *dev, bool probe);
>  int pcie_flr(struct pci_dev *dev);
>  int __pci_reset_function_locked(struct pci_dev *dev);
>  int pci_reset_function(struct pci_dev *dev);
> diff --git a/include/linux/pci_hotplug.h b/include/linux/pci_hotplug.h
> index b482e42d7153..608c012eb8ac 100644
> --- a/include/linux/pci_hotplug.h
> +++ b/include/linux/pci_hotplug.h
> @@ -44,7 +44,7 @@ struct hotplug_slot_ops {
>         int (*get_attention_status)     (struct hotplug_slot *slot, u8 *value);
>         int (*get_latch_status)         (struct hotplug_slot *slot, u8 *value);
>         int (*get_adapter_status)       (struct hotplug_slot *slot, u8 *value);
> -       int (*reset_slot)               (struct hotplug_slot *slot, int probe);
> +       int (*reset_slot)               (struct hotplug_slot *slot, bool probe);
>  };
>
>  /**
> --
> 2.32.0
>


^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-08-14  4:10       ` Bjorn Helgaas
@ 2021-08-14 16:16         ` Shanker R Donthineni
  2021-08-16 17:07           ` Bjorn Helgaas
  0 siblings, 1 reply; 21+ messages in thread
From: Shanker R Donthineni @ 2021-08-14 16:16 UTC (permalink / raw)
  To: Bjorn Helgaas
  Cc: Amey Narkhede, Bjorn Helgaas, alex.williamson, Raphael Norwitz,
	linux-pci, linux-kernel, kw, Sinan Kaya, Len Brown,
	Rafael J . Wysocki, Benjamin Herrenschmidt, Mika Westerberg

Hi Bjorn,

On 8/13/21 11:10 PM, Bjorn Helgaas wrote:
>>>> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
>>>> index eaddbf701759..dae021322b3f 100644
>>>> --- a/drivers/pci/pci-acpi.c
>>>> +++ b/drivers/pci/pci-acpi.c
>>>> @@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
>>>>               return false;
>>>>
>>>>       /* Assume D3 support if the bridge is power-manageable by ACPI. */
>>>> -     pci_set_acpi_fwnode(dev);
>>>>       adev = ACPI_COMPANION(&dev->dev);
>>> I *think* the Root Port code farther down in this function is also now
>>> unnecessary:
>>>
>>>   acpi_pci_bridge_d3(...)
>>>   {
>>>     ...
>>>     root = pcie_find_root_port(dev);
>>>     adev = ACPI_COMPANION(&root->dev);
>>>     if (root == dev) {
>>>       /*
>>>        * It is possible that the ACPI companion is not yet bound
>>>        * for the root port so look it up manually here.
>>>        */
>>>       if (!adev && !pci_dev_is_added(root))
>>>         adev = acpi_pci_find_companion(&root->dev);
>>>     }
>>>
>>> Since we're now setting the ACPI_COMPANION for every pci_dev long
>>> before we get here, I think this could now be simplified to something
>>> like this:
>>>
>>>   acpi_pci_bridge_d3(...)
>>>   {
>>>     if (!dev->is_hotplug_bridge)
>>>       return false;
>>>
>>>     adev = ACPI_COMPANION(&dev->dev);
>>>     if (adev && acpi_device_power_manageable(adev))
>>>       return true;
>>>
>>>     root = pcie_find_root_port(dev);
>>>     if (!root)
>>>       return false;
>>>
>>>     adev = ACPI_COMPANION(&root->dev);
>>>     if (!adev)
>>>       return false;
>>>
>>>     rc = acpi_dev_get_property(dev, "HotPlugSupportInD3",
>>>                                ACPI_TYPE_INTEGER, &val);
>>>     if (rc < 0)
>>>       return false;
>>>
>>>     return val == 1;
>>>   }
>> Agree, thanks for your suggestion. Yes, it can be simplified too.
>> Can I do something like this using the unified device property API?
>>
>> static bool acpi_pci_bridge_d3(struct pci_dev *dev)
>> {
>>         struct acpi_device *adev;
>>         struct pci_dev *root;
>>         u8 val;
>>
>>         if (!dev->is_hotplug_bridge)
>>                 return false;
>>
>>         adev = ACPI_COMPANION(&dev->dev);
>>         if (adev && acpi_device_power_manageable(adev))
>>                 return true;
>>
>>         root = pcie_find_root_port(dev);
>>         if (!root)
>>                 return false;
>>
>>         if (device_property_read_u8(&root->dev, "HotPlugSupportInD3", &val))
>>                 return false;
> I guess that might be OK.
>
> TBH I don't really like the device_property_read_u8() thing because
> (1) we know this is an ACPI property and I don't see a reason to use
> an "generic" interface that doesn't buy us anything, and (2) the
> connection to the source of the data (a _DSD method) is really, really
> hard to find.
>
> Admittedly, it's still pretty hard to connect acpi_dev_get_property()
> with "_DSD".  The only real clue is the comment about "Look for a
> special _DSD property ..."
>
Does it satisfy you if I change the comment and still use device_property API?

static bool acpi_pci_bridge_d3(struct pci_dev *dev)
{
        struct pci_dev *rpdev;
        u8 val;

        if (!dev->is_hotplug_bridge)
                return false;

        /* Assume D3 support if the bridge is power-manageable by ACPI. */
        if (acpi_pci_power_manageable(dev))
                return true;

        /*
         * Look for 'HotPlugSupportInD3' property for the root port and if
         * it is set we know the hierarchy behind it supports D3 just fine.
         */
        rpdev = pcie_find_root_port(dev);
        if (!rpdev)
                return false;

        if (device_property_read_u8(&rpdev->dev, "HotPlugSupportInD3", &val))
                return false;

        return val == 1;
}

If not, I'll do changes like this.

static bool acpi_pci_bridge_d3(struct pci_dev *dev)
{
        const union acpi_object *obj;
        struct acpi_device *adev;
        struct pci_dev *rpdev;


        if (!dev->is_hotplug_bridge)
                return false;

        /* Assume D3 support if the bridge is power-manageable by ACPI. */
        if (acpi_pci_power_manageable(dev))
                return true;

        /*
         * Look for 'HotPlugSupportInD3' property for the root port and if
         * it is set we know the hierarchy behind it supports D3 just fine.
         */
        rpdev = pcie_find_root_port(dev);
        if (!rpdev)
                return false;

        adev = ACPI_COMPANION(&rpdev->dev);
        if (!adev)
                return false;

       if (acpi_dev_get_property(adev, "HotPlugSupportInD3",
                                   ACPI_TYPE_INTEGER, &obj) < 0)
                return false;

        return obj->integer.value == 1;
}



^ permalink raw reply	[flat|nested] 21+ messages in thread
* Re: [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-08-14 16:16         ` Shanker R Donthineni
@ 2021-08-16 17:07           ` Bjorn Helgaas
  0 siblings, 0 replies; 21+ messages in thread
From: Bjorn Helgaas @ 2021-08-16 17:07 UTC (permalink / raw)
  To: Shanker R Donthineni
  Cc: Amey Narkhede, Bjorn Helgaas, alex.williamson, Raphael Norwitz,
	linux-pci, linux-kernel, kw, Sinan Kaya, Len Brown,
	Rafael J . Wysocki, Benjamin Herrenschmidt, Mika Westerberg

On Sat, Aug 14, 2021 at 11:16:11AM -0500, Shanker R Donthineni wrote:
> Hi Bjorn,
> 
> On 8/13/21 11:10 PM, Bjorn Helgaas wrote:
> >>>> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> >>>> index eaddbf701759..dae021322b3f 100644
> >>>> --- a/drivers/pci/pci-acpi.c
> >>>> +++ b/drivers/pci/pci-acpi.c
> >>>> @@ -952,7 +952,6 @@ static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> >>>>               return false;
> >>>>
> >>>>       /* Assume D3 support if the bridge is power-manageable by ACPI. */
> >>>> -     pci_set_acpi_fwnode(dev);
> >>>>       adev = ACPI_COMPANION(&dev->dev);
> >>> I *think* the Root Port code farther down in this function is also now
> >>> unnecessary:
> >>>
> >>>   acpi_pci_bridge_d3(...)
> >>>   {
> >>>     ...
> >>>     root = pcie_find_root_port(dev);
> >>>     adev = ACPI_COMPANION(&root->dev);
> >>>     if (root == dev) {
> >>>       /*
> >>>        * It is possible that the ACPI companion is not yet bound
> >>>        * for the root port so look it up manually here.
> >>>        */
> >>>       if (!adev && !pci_dev_is_added(root))
> >>>         adev = acpi_pci_find_companion(&root->dev);
> >>>     }
> >>>
> >>> Since we're now setting the ACPI_COMPANION for every pci_dev long
> >>> before we get here, I think this could now be simplified to something
> >>> like this:
> >>>
> >>>   acpi_pci_bridge_d3(...)
> >>>   {
> >>>     if (!dev->is_hotplug_bridge)
> >>>       return false;
> >>>
> >>>     adev = ACPI_COMPANION(&dev->dev);
> >>>     if (adev && acpi_device_power_manageable(adev))
> >>>       return true;
> >>>
> >>>     root = pcie_find_root_port(dev);
> >>>     if (!root)
> >>>       return false;
> >>>
> >>>     adev = ACPI_COMPANION(&root->dev);
> >>>     if (!adev)
> >>>       return false;
> >>>
> >>>     rc = acpi_dev_get_property(dev, "HotPlugSupportInD3",
> >>>                                ACPI_TYPE_INTEGER, &val);
> >>>     if (rc < 0)
> >>>       return false;
> >>>
> >>>     return val == 1;
> >>>   }
> >> Agree, thanks for your suggestion. Yes, it can be simplified too.
> >> Can I do something like this using the unified device property API?
> >>
> >> static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> >> {
> >>         struct acpi_device *adev;
> >>         struct pci_dev *root;
> >>         u8 val;
> >>
> >>         if (!dev->is_hotplug_bridge)
> >>                 return false;
> >>
> >>         adev = ACPI_COMPANION(&dev->dev);
> >>         if (adev && acpi_device_power_manageable(adev))
> >>                 return true;
> >>
> >>         root = pcie_find_root_port(dev);
> >>         if (!root)
> >>                 return false;
> >>
> >>         if (device_property_read_u8(&root->dev, "HotPlugSupportInD3", &val))
> >>                 return false;
> > I guess that might be OK.
> >
> > TBH I don't really like the device_property_read_u8() thing because
> > (1) we know this is an ACPI property and I don't see a reason to use
> > an "generic" interface that doesn't buy us anything, and (2) the
> > connection to the source of the data (a _DSD method) is really, really
> > hard to find.
> >
> > Admittedly, it's still pretty hard to connect acpi_dev_get_property()
> > with "_DSD".  The only real clue is the comment about "Look for a
> > special _DSD property ..."
> >
> Does it satisfy you if I change the comment and still use device_property API?
> 
> static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> {
>         struct pci_dev *rpdev;
>         u8 val;
> 
>         if (!dev->is_hotplug_bridge)
>                 return false;
> 
>         /* Assume D3 support if the bridge is power-manageable by ACPI. */
>         if (acpi_pci_power_manageable(dev))
>                 return true;
> 
>         /*
>          * Look for 'HotPlugSupportInD3' property for the root port and if
>          * it is set we know the hierarchy behind it supports D3 just fine.
>          */
>         rpdev = pcie_find_root_port(dev);
>         if (!rpdev)
>                 return false;
> 
>         if (device_property_read_u8(&rpdev->dev, "HotPlugSupportInD3", &val))
>                 return false;
> 
>         return val == 1;
> }
> 
> If not, I'll do changes like this.

I guess either one is fine.  But I think we should extend the comment
and commit log to make it clear that device_property_read_u8() and
acpi_dev_get_property() are ultimately looking for a _DSD.  I should
have asked for this when we merged 26ad34d510a8 ("PCI / ACPI:
Whitelist D3 for more PCIe hotplug ports") in the first place.

If we expect that power management *should* be enabled for a bridge,
and we observe that it *isn't* enabled, it is unreasonably difficult
to figure out from the code what is missing in the firmware, namely,
the _DSD laid out in the commit log for 26ad34d510a8.

> static bool acpi_pci_bridge_d3(struct pci_dev *dev)
> {
>         const union acpi_object *obj;
>         struct acpi_device *adev;
>         struct pci_dev *rpdev;
> 
> 
>         if (!dev->is_hotplug_bridge)
>                 return false;
> 
>         /* Assume D3 support if the bridge is power-manageable by ACPI. */
>         if (acpi_pci_power_manageable(dev))
>                 return true;
> 
>         /*
>          * Look for 'HotPlugSupportInD3' property for the root port and if
>          * it is set we know the hierarchy behind it supports D3 just fine.
>          */
>         rpdev = pcie_find_root_port(dev);
>         if (!rpdev)
>                 return false;
> 
>         adev = ACPI_COMPANION(&rpdev->dev);
>         if (!adev)
>                 return false;
> 
>        if (acpi_dev_get_property(adev, "HotPlugSupportInD3",
>                                    ACPI_TYPE_INTEGER, &obj) < 0)
>                 return false;
> 
>         return obj->integer.value == 1;
> }
> 
> 

^ permalink raw reply	[flat|nested] 21+ messages in thread
end of thread, other threads:[~2021-08-16 17:07 UTC | newest]

Thread overview: 21+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-08-05 16:29 [PATCH v15 0/9] PCI: Expose and manage PCI device reset Amey Narkhede
2021-08-05 16:29 ` [PATCH v15 1/9] PCI: Cache PCIe FLR capability Amey Narkhede
2021-08-09 11:13   ` Raphael Norwitz
2021-08-05 16:29 ` [PATCH v15 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
2021-08-09 11:15   ` Raphael Norwitz
2021-08-05 16:29 ` [PATCH v15 3/9] PCI: Add new array for keeping track of ordering of " Amey Narkhede
2021-08-09 11:18   ` Raphael Norwitz
2021-08-05 16:29 ` [PATCH v15 4/9] PCI: Remove reset_fn field from pci_dev Amey Narkhede
2021-08-05 16:29 ` [PATCH v15 5/9] PCI: Allow userspace to query and set device reset mechanism Amey Narkhede
2021-08-09 11:23   ` Raphael Norwitz
2021-08-05 16:29 ` [PATCH v15 6/9] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
2021-08-05 16:29 ` [PATCH v15 7/9] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
2021-08-13 23:04   ` Bjorn Helgaas
2021-08-14  3:35     ` Shanker R Donthineni
2021-08-14  4:10       ` Bjorn Helgaas
2021-08-14 16:16         ` Shanker R Donthineni
2021-08-16 17:07           ` Bjorn Helgaas
2021-08-05 16:29 ` [PATCH v15 8/9] PCI: Add support for ACPI _RST reset method Amey Narkhede
2021-08-05 16:29 ` [PATCH v15 9/9] PCI: Change the type of probe argument in reset functions Amey Narkhede
2021-08-14 14:05   ` Shanker R Donthineni
2021-08-12 13:03 ` [PATCH v15 0/9] PCI: Expose and manage PCI device reset Shanker R Donthineni

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