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* [PATCH v9 0/8] Expose and manage PCI device reset
@ 2021-07-05 14:21 Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
                   ` (7 more replies)
  0 siblings, 8 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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 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 (5):
  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/sysfs: 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              |   4 +-
 drivers/pci/pci-acpi.c                        |  38 +++-
 drivers/pci/pci-sysfs.c                       | 107 ++++++++-
 drivers/pci/pci.c                             | 215 ++++++++++--------
 drivers/pci/pci.h                             |  23 +-
 drivers/pci/pcie/aer.c                        |  12 +-
 drivers/pci/probe.c                           |  17 +-
 drivers/pci/quirks.c                          |  42 ++--
 drivers/pci/remove.c                          |   1 -
 include/linux/pci.h                           |  17 +-
 include/linux/pci_hotplug.h                   |   2 +-
 15 files changed, 361 insertions(+), 144 deletions(-)

--
2.32.0

^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-05 14:37   ` Amey Narkhede
  2021-07-11 16:40   ` Raphael Norwitz
  2021-07-05 14:21 ` [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of " Amey Narkhede
                   ` (6 subsequent siblings)
  7 siblings, 2 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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 has_pcie_flr bitfield in struct pci_dev to indicate support for PCIe
FLR to avoid reading PCI_EXP_DEVCAP multiple times.

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                          | 59 +++++++++++-----------
 drivers/pci/pcie/aer.c                     | 12 ++---
 drivers/pci/probe.c                        |  6 ++-
 drivers/pci/quirks.c                       |  9 ++--
 include/linux/pci.h                        |  3 +-
 6 files changed, 45 insertions(+), 48 deletions(-)

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index facc8e6bc..15d6c8452 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 452351025..fefa6d7b3 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4611,32 +4611,12 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pci_wait_for_pending_transaction);
 
-/**
- * pcie_has_flr - check if a device supports function level resets
- * @dev: device to check
- *
- * Returns true if the device advertises support for PCIe function level
- * resets.
- */
-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;
-}
-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)
 {
@@ -4659,6 +4639,28 @@ 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 (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
+		return -ENOTTY;
+
+	if (!dev->has_pcie_flr)
+		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;
@@ -5139,11 +5141,9 @@ 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;
@@ -5174,8 +5174,9 @@ 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 ec943cee5..98077595a 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/probe.c b/drivers/pci/probe.c
index 3a62d09b8..a95252113 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1487,6 +1487,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
 {
 	int pos;
 	u16 reg16;
+	u32 reg32;
 	int type;
 	struct pci_dev *parent;
 
@@ -1497,8 +1498,9 @@ 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, &reg32);
+	pdev->pcie_mpss = reg32 & PCI_EXP_DEVCAP_PAYLOAD;
+	pdev->has_pcie_flr = reg32 & PCI_EXP_DEVCAP_FLR ? 1 : 0;
 
 	parent = pci_upstream_bridge(pdev);
 	if (!parent)
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d85914afe..f977ba79a 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;
+	int ret = pcie_reset_flr(dev, probe);
 
 	if (probe)
-		return 0;
-
-	pcie_flr(dev);
+		return ret;
 
 	msleep(250);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c20211e59..d432428fd 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -337,6 +337,7 @@ struct pci_dev {
 	u8		msi_cap;	/* MSI capability offset */
 	u8		msix_cap;	/* MSI-X capability offset */
 	u8		pcie_mpss:3;	/* PCIe Max Payload Size Supported */
+	u8		has_pcie_flr:1; /* PCIe FLR supported */
 	u8		rom_base_reg;	/* Config register controlling ROM */
 	u8		pin;		/* Interrupt pin this device uses */
 	u16		pcie_flags_reg;	/* Cached PCIe Capabilities Register */
@@ -1225,7 +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] 18+ messages in thread

* [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of reset methods
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-11 16:42   ` Raphael Norwitz
  2021-07-05 14:21 ` [PATCH v9 3/8] PCI: Remove reset_fn field from pci_dev Amey Narkhede
                   ` (5 subsequent siblings)
  7 siblings, 1 reply; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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   | 92 ++++++++++++++++++++++++++-------------------
 drivers/pci/pci.h   |  9 ++++-
 drivers/pci/probe.c |  5 +--
 include/linux/pci.h |  7 ++++
 4 files changed, 70 insertions(+), 43 deletions(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index fefa6d7b3..42440cb10 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -72,6 +72,14 @@ static void pci_dev_d3_sleep(struct pci_dev *dev)
 		msleep(delay);
 }
 
+int pci_reset_supported(struct pci_dev *dev)
+{
+	u8 null_reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
+
+	return memcmp(null_reset_methods,
+		      dev->reset_methods, sizeof(null_reset_methods));
+}
+
 #ifdef CONFIG_PCI_DOMAINS
 int pci_domains_supported = 1;
 #endif
@@ -5104,6 +5112,15 @@ static void pci_dev_restore(struct pci_dev *dev)
 		err_handler->reset_done(dev);
 }
 
+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.
@@ -5126,65 +5143,62 @@ 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 && (m = dev->reset_methods[i]); i++) {
+		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.
+ * to reads and writes to its PCI config space in order to use this function.
  *
- * 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 i, n, rc;
+	u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
+
+	n = 0;
+
+	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;
+	for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
+		rc = pci_reset_fn_methods[i].reset_fn(dev, 1);
+		if (!rc)
+			reset_methods[n++] = i;
+		else if (rc != -ENOTTY)
+			break;
+	}
 
-	return pci_reset_bus_function(dev, 1);
+	memcpy(dev->reset_methods, reset_methods, sizeof(reset_methods));
 }
 
 /**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 37c913bbc..db1ad94e7 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);
+int 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 +607,12 @@ 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;
+};
+
+extern const struct pci_reset_fn_method pci_reset_fn_methods[];
 #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 a95252113..a3e9a9c88 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2406,9 +2406,8 @@ 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 d432428fd..9f3e85f33 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] 18+ messages in thread

* [PATCH v9 3/8] PCI: Remove reset_fn field from pci_dev
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of " Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
                   ` (4 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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 516f166ce..336d149ee 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 beb8d1f4f..316f70c3e 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 42440cb10..d5c16492c 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5221,7 +5221,7 @@ 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);
@@ -5257,7 +5257,7 @@ 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);
@@ -5280,7 +5280,7 @@ 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 a3e9a9c88..221a20415 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2407,7 +2407,6 @@ 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 f977ba79a..e86cf4a3b 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 dd12c2fcc..4c54c7505 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 9f3e85f33..f34563831 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	[flat|nested] 18+ messages in thread

* [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
                   ` (2 preceding siblings ...)
  2021-07-05 14:21 ` [PATCH v9 3/8] PCI: Remove reset_fn field from pci_dev Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-06  5:16   ` Leon Romanovsky
  2021-07-11 16:51   ` Raphael Norwitz
  2021-07-05 14:21 ` [PATCH v9 5/8] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
                   ` (3 subsequent siblings)
  7 siblings, 2 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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                 | 103 ++++++++++++++++++++++++
 2 files changed, 122 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ef00fada2..43f4e33c7 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 comma 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 316f70c3e..8a740e211 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1334,6 +1334,108 @@ static const struct attribute_group pci_dev_rom_attr_group = {
 	.is_bin_visible = pci_dev_rom_attr_is_visible,
 };
 
+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, idx;
+
+	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
+		idx = pdev->reset_methods[i];
+		if (!idx)
+			break;
+
+		len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "",
+				     pci_reset_fn_methods[idx].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 n = 0;
+	char *name, *options = NULL;
+	u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
+
+	if (count >= (PAGE_SIZE - 1))
+		return -EINVAL;
+
+	if (sysfs_streq(buf, "")) {
+		pci_warn(pdev, "All device reset methods disabled by user");
+		goto set_reset_methods;
+	}
+
+	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) {
+		int i;
+
+		if (sysfs_streq(name, ""))
+			continue;
+
+		name = strim(name);
+
+		for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
+			if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
+			    !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
+				reset_methods[n++] = i;
+				break;
+			}
+		}
+
+		if (i == PCI_NUM_RESET_METHODS) {
+			kfree(options);
+			return -EINVAL;
+		}
+	}
+
+	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
+		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
+
+set_reset_methods:
+	memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods));
+	kfree(options);
+	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;
+}
+
+static 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,
+};
+
 static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t count)
 {
@@ -1491,6 +1593,7 @@ 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,
-- 
2.32.0


^ permalink raw reply	[flat|nested] 18+ messages in thread

* [PATCH v9 5/8] PCI: Define a function to set ACPI_COMPANION in pci_dev
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
                   ` (3 preceding siblings ...)
  2021-07-05 14:21 ` [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 6/8] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
                   ` (2 subsequent siblings)
  7 siblings, 0 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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>
---
 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 36bc23e21..eaddbf701 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 db1ad94e7..990b73e90 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -704,7 +704,9 @@ 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	[flat|nested] 18+ messages in thread

* [PATCH v9 6/8] PCI: Setup ACPI fwnode early and at the same time with OF
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
                   ` (4 preceding siblings ...)
  2021-07-05 14:21 ` [PATCH v9 5/8] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 7/8] PCI: Add support for ACPI _RST reset method Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 8/8] PCI: Change the type of probe argument in reset functions Amey Narkhede
  7 siblings, 0 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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() WAR.

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>
---
 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 eaddbf701..dae021322 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 221a20415..ba0137322 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1790,6 +1790,9 @@ 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);
 
 	/*
@@ -1925,6 +1928,7 @@ 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:
@@ -2352,10 +2356,7 @@ 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	[flat|nested] 18+ messages in thread

* [PATCH v9 7/8] PCI: Add support for ACPI _RST reset method
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
                   ` (5 preceding siblings ...)
  2021-07-05 14:21 ` [PATCH v9 6/8] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-05 14:21 ` [PATCH v9 8/8] PCI: Change the type of probe argument in reset functions Amey Narkhede
  7 siblings, 0 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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>
---
 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 dae021322..b6de71d15 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 -EINVAL;
+	}
+
+	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 d5c16492c..1e64dbd3e 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5115,6 +5115,7 @@ static void pci_dev_restore(struct pci_dev *dev)
 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 990b73e90..2c12017ed 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -705,7 +705,13 @@ 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 f34563831..c3b0d771c 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	[flat|nested] 18+ messages in thread

* [PATCH v9 8/8] PCI: Change the type of probe argument in reset functions
  2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
                   ` (6 preceding siblings ...)
  2021-07-05 14:21 ` [PATCH v9 7/8] PCI: Add support for ACPI _RST reset method Amey Narkhede
@ 2021-07-05 14:21 ` Amey Narkhede
  2021-07-05 23:39   ` kernel test robot
  7 siblings, 1 reply; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:21 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 enum pci_reset_mode_t to make the context of probe argument
in reset functions clear and the code easier to read.  Change the type of
probe argument in functions which implement reset methods from int to
pci_reset_mode_t to make the intent clear.

Add a new line in return statement of pci_reset_bus_function().

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              |  4 +-
 drivers/pci/pci-acpi.c                        | 10 ++-
 drivers/pci/pci-sysfs.c                       |  6 +-
 drivers/pci/pci.c                             | 85 ++++++++++++-------
 drivers/pci/pci.h                             | 12 +--
 drivers/pci/pcie/aer.c                        |  2 +-
 drivers/pci/quirks.c                          | 37 ++++----
 include/linux/pci.h                           |  8 +-
 include/linux/pci_hotplug.h                   |  2 +-
 12 files changed, 105 insertions(+), 67 deletions(-)

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index 15d6c8452..f97fa8e99 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 336d149ee..6e666be69 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 4fd200d8b..87da03adc 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, pci_reset_mode_t mode);
 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 fb3840e22..24b3c8787 100644
--- a/drivers/pci/hotplug/pciehp_hpc.c
+++ b/drivers/pci/hotplug/pciehp_hpc.c
@@ -834,14 +834,14 @@ 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, pci_reset_mode_t mode)
 {
 	struct controller *ctrl = to_ctrl(hotplug_slot);
 	struct pci_dev *pdev = ctrl_dev(ctrl);
 	u16 stat_mask = 0, ctrl_mask = 0;
 	int rc;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	down_write(&ctrl->reset_lock);
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index b6de71d15..a92ed574a 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -944,16 +944,20 @@ 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, pci_reset_mode_t mode)
 {
 	acpi_handle handle = ACPI_HANDLE(&dev->dev);
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (!handle || !acpi_has_method(handle, "_RST"))
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) {
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 8a740e211..dcf19f6d6 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1393,7 +1393,8 @@ static ssize_t reset_method_store(struct device *dev,
 
 		for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
 			if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
-			    !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
+			    !pci_reset_fn_methods[i].reset_fn(pdev,
+							      PCI_RESET_PROBE)) {
 				reset_methods[n++] = i;
 				break;
 			}
@@ -1405,7 +1406,8 @@ static ssize_t reset_method_store(struct device *dev,
 		}
 	}
 
-	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
+	if (!pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE) &&
+	    reset_methods[0] != 1)
 		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
 
 set_reset_methods:
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1e64dbd3e..60204cee6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4650,30 +4650,36 @@ 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.
+ * @mode: 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, pci_reset_mode_t mode)
 {
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
 		return -ENOTTY;
 
 	if (!dev->has_pcie_flr)
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	return pcie_flr(dev);
 }
 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, pci_reset_mode_t mode)
 {
 	int pos;
 	u8 cap;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	pos = pci_find_capability(dev, PCI_CAP_ID_AF);
 	if (!pos)
 		return -ENOTTY;
@@ -4685,7 +4691,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
 	if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	/*
@@ -4716,7 +4722,7 @@ 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.
+ * @mode: 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
@@ -4728,10 +4734,13 @@ 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, pci_reset_mode_t mode)
 {
 	u16 csr;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET)
 		return -ENOTTY;
 
@@ -4739,7 +4748,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	if (dev->current_state != PCI_D0)
@@ -4988,10 +4997,13 @@ 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, pci_reset_mode_t mode)
 {
 	struct pci_dev *pdev;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (pci_is_root_bus(dev->bus) || dev->subordinate ||
 	    !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
 		return -ENOTTY;
@@ -5000,44 +5012,47 @@ static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
 		if (pdev != dev)
 			return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	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, pci_reset_mode_t mode)
 {
 	int rc = -ENOTTY;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (!hotplug || !try_module_get(hotplug->owner))
 		return rc;
 
 	if (hotplug->ops->reset_slot)
-		rc = hotplug->ops->reset_slot(hotplug, probe);
+		rc = hotplug->ops->reset_slot(hotplug, mode);
 
 	module_put(hotplug->owner);
 
 	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, pci_reset_mode_t mode)
 {
 	if (dev->multifunction || dev->subordinate || !dev->slot ||
 	    dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)
 		return -ENOTTY;
 
-	return pci_reset_hotplug_slot(dev->slot->hotplug, probe);
+	return pci_reset_hotplug_slot(dev->slot->hotplug, mode);
 }
 
-static int pci_reset_bus_function(struct pci_dev *dev, int probe)
+static int pci_reset_bus_function(struct pci_dev *dev, pci_reset_mode_t mode)
 {
 	int rc;
 
-	rc = pci_dev_reset_slot_function(dev, probe);
+	rc = pci_dev_reset_slot_function(dev, mode);
 	if (rc != -ENOTTY)
 		return rc;
-	return pci_parent_bus_reset(dev, probe);
+	return pci_parent_bus_reset(dev, mode);
 }
 
 static void pci_dev_lock(struct pci_dev *dev)
@@ -5157,7 +5172,7 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 	 * mechanisms might be broken on the device.
 	 */
 	for (i = 0; i <  PCI_NUM_RESET_METHODS && (m = dev->reset_methods[i]); i++) {
-		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)
@@ -5192,7 +5207,7 @@ void pci_init_reset_methods(struct pci_dev *dev)
 	might_sleep();
 
 	for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
-		rc = pci_reset_fn_methods[i].reset_fn(dev, 1);
+		rc = pci_reset_fn_methods[i].reset_fn(dev, PCI_RESET_PROBE);
 		if (!rc)
 			reset_methods[n++] = i;
 		else if (rc != -ENOTTY)
@@ -5509,21 +5524,24 @@ 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, pci_reset_mode_t mode)
 {
 	int rc;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (!slot || !pci_slot_resetable(slot))
 		return -ENOTTY;
 
-	if (!probe)
+	if (mode != PCI_RESET_PROBE)
 		pci_slot_lock(slot);
 
 	might_sleep();
 
-	rc = pci_reset_hotplug_slot(slot->hotplug, probe);
+	rc = pci_reset_hotplug_slot(slot->hotplug, mode);
 
-	if (!probe)
+	if (mode != PCI_RESET_PROBE)
 		pci_slot_unlock(slot);
 
 	return rc;
@@ -5537,7 +5555,7 @@ 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);
 
@@ -5560,14 +5578,14 @@ 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
@@ -5576,14 +5594,17 @@ 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, pci_reset_mode_t mode)
 {
 	int ret;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	if (!bus->self || !pci_bus_resetable(bus))
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	pci_bus_lock(bus);
@@ -5622,14 +5643,14 @@ 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);
 }
 
 /**
@@ -5640,7 +5661,7 @@ 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);
 
@@ -5654,7 +5675,7 @@ 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 2c12017ed..06be9e6fa 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -604,19 +604,19 @@ 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, pci_reset_mode_t mode);
 };
 
 struct pci_reset_fn_method {
-	int (*reset_fn)(struct pci_dev *pdev, int probe);
+	int (*reset_fn)(struct pci_dev *pdev, pci_reset_mode_t mode);
 	char *name;
 };
 
 extern const struct pci_reset_fn_method pci_reset_fn_methods[];
 #ifdef CONFIG_PCI_QUIRKS
-int pci_dev_specific_reset(struct pci_dev *dev, int probe);
+int pci_dev_specific_reset(struct pci_dev *dev, pci_reset_mode_t mode);
 #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, pci_reset_mode_t mode)
 {
 	return -ENOTTY;
 }
@@ -705,9 +705,9 @@ 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, pci_reset_mode_t mode);
 #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, pci_reset_mode_t mode)
 {
 	return -ENOTTY;
 }
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 98077595a..cfa7a1775 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 e86cf4a3b..e7f15fc02 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, pci_reset_mode_t mode)
 {
 	/*
 	 * http://www.intel.com/content/dam/doc/datasheet/82599-10-gbe-controller-datasheet.pdf
@@ -3679,7 +3679,7 @@ static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
 	 * Thus we must call pcie_flr() directly without first checking if it is
 	 * supported.
 	 */
-	if (!probe)
+	if (mode == PCI_RESET_DO_RESET)
 		pcie_flr(dev);
 	return 0;
 }
@@ -3691,13 +3691,13 @@ 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, pci_reset_mode_t mode)
 {
 	void __iomem *mmio_base;
 	unsigned long timeout;
 	u32 val;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	mmio_base = pci_iomap(dev, 0, 0);
@@ -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, pci_reset_mode_t mode)
 {
 	u16 old_command;
 	u16 msix_flags;
@@ -3750,7 +3750,7 @@ static int reset_chelsio_generic_dev(struct pci_dev *dev, int probe)
 	 * If this is the "probe" phase, return 0 indicating that we can
 	 * reset this device.
 	 */
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	/*
@@ -3812,17 +3812,17 @@ 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, pci_reset_mode_t mode)
 {
 	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)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	bar = pci_iomap(dev, 0, NVME_REG_CC + sizeof(cfg));
@@ -3886,11 +3886,13 @@ 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, pci_reset_mode_t mode)
 {
-	int ret = pcie_reset_flr(dev, probe);
+	int ret;
+
+	ret = pcie_reset_flr(dev, mode);
 
-	if (probe)
+	if (ret || mode == PCI_RESET_PROBE)
 		return ret;
 
 	msleep(250);
@@ -3906,13 +3908,13 @@ 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, pci_reset_mode_t mode)
 {
 	unsigned long timeout;
 	void __iomem *bar;
 	u32 val;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	bar = pci_iomap(pdev, 0, 0);
@@ -3983,16 +3985,19 @@ 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, pci_reset_mode_t mode)
 {
 	const struct pci_dev_reset_methods *i;
 
+	if (mode >= PCI_RESET_MODE_MAX)
+		return -EINVAL;
+
 	for (i = pci_dev_reset_methods; i->reset; i++) {
 		if ((i->vendor == dev->vendor ||
 		     i->vendor == (u16)PCI_ANY_ID) &&
 		    (i->device == dev->device ||
 		     i->device == (u16)PCI_ANY_ID))
-			return i->reset(dev, probe);
+			return i->reset(dev, mode);
 	}
 
 	return -ENOTTY;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c3b0d771c..0d650c873 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -52,6 +52,12 @@
 /* Number of reset methods used in pci_reset_fn_methods array in pci.c */
 #define PCI_NUM_RESET_METHODS 7
 
+typedef enum pci_reset_mode {
+	PCI_RESET_DO_RESET,
+	PCI_RESET_PROBE,
+	PCI_RESET_MODE_MAX,
+} pci_reset_mode_t;
+
 /*
  * The PCI interface treats multi-function devices as independent
  * devices.  The slot/function address of each device is encoded
@@ -1232,7 +1238,7 @@ 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, pci_reset_mode_t mode);
 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 b482e42d7..9e8da46e7 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, pci_reset_mode_t mode);
 };
 
 /**
-- 
2.32.0


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods
  2021-07-05 14:21 ` [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
@ 2021-07-05 14:37   ` Amey Narkhede
  2021-07-08 20:24     ` Alex Williamson
  2021-07-11 16:40   ` Raphael Norwitz
  1 sibling, 1 reply; 18+ messages in thread
From: Amey Narkhede @ 2021-07-05 14:37 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

On 21/07/05 07:51PM, Amey Narkhede wrote:
> Add has_pcie_flr bitfield in struct pci_dev to indicate support for PCIe
> FLR to avoid reading PCI_EXP_DEVCAP multiple times.
>
> 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                          | 59 +++++++++++-----------
>  drivers/pci/pcie/aer.c                     | 12 ++---
>  drivers/pci/probe.c                        |  6 ++-
>  drivers/pci/quirks.c                       |  9 ++--
>  include/linux/pci.h                        |  3 +-
>  6 files changed, 45 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
[...]
> index 3a62d09b8..a95252113 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1487,6 +1487,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
>  {
>  	int pos;
>  	u16 reg16;
> +	u32 reg32;
>  	int type;
>  	struct pci_dev *parent;
>
> @@ -1497,8 +1498,9 @@ 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, &reg32);
> +	pdev->pcie_mpss = reg32 & PCI_EXP_DEVCAP_PAYLOAD;
> +	pdev->has_pcie_flr = reg32 & PCI_EXP_DEVCAP_FLR ? 1 : 0;
On the side note, removing ternary here as Alex suggested doesn't work
for some reason.
[...]

Thanks,
Amey

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 8/8] PCI: Change the type of probe argument in reset functions
  2021-07-05 14:21 ` [PATCH v9 8/8] PCI: Change the type of probe argument in reset functions Amey Narkhede
@ 2021-07-05 23:39   ` kernel test robot
  0 siblings, 0 replies; 18+ messages in thread
From: kernel test robot @ 2021-07-05 23:39 UTC (permalink / raw)
  To: Amey Narkhede, Bjorn Helgaas
  Cc: kbuild-all, alex.williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki

[-- Attachment #1: Type: text/plain, Size: 3061 bytes --]

Hi Amey,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on pci/next]
[cannot apply to pm/linux-next cryptodev/master crypto/master linus/master v5.13 next-20210701]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Amey-Narkhede/Expose-and-manage-PCI-device-reset/20210705-222358
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: powerpc-allyesconfig (attached as .config)
compiler: powerpc64-linux-gcc (GCC) 9.3.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/0day-ci/linux/commit/4866dd22881441f63dc57f682b3acbc539c83fe2
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Amey-Narkhede/Expose-and-manage-PCI-device-reset/20210705-222358
        git checkout 4866dd22881441f63dc57f682b3acbc539c83fe2
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All errors (new ones prefixed by >>):

>> drivers/pci/hotplug/pnv_php.c:603:17: error: initialization of 'int (*)(struct hotplug_slot *, pci_reset_mode_t)' {aka 'int (*)(struct hotplug_slot *, enum pci_reset_mode)'} from incompatible pointer type 'int (*)(struct hotplug_slot *, int)' [-Werror=incompatible-pointer-types]
     603 |  .reset_slot  = pnv_php_reset_slot,
         |                 ^~~~~~~~~~~~~~~~~~
   drivers/pci/hotplug/pnv_php.c:603:17: note: (near initialization for 'php_slot_ops.reset_slot')
   cc1: some warnings being treated as errors


vim +603 drivers/pci/hotplug/pnv_php.c

66725152fb9f17 Gavin Shan        2016-05-20  595  
81c4b5bf30de01 Lukas Wunner      2018-09-08  596  static const struct hotplug_slot_ops php_slot_ops = {
66725152fb9f17 Gavin Shan        2016-05-20  597  	.get_power_status	= pnv_php_get_power_state,
66725152fb9f17 Gavin Shan        2016-05-20  598  	.get_adapter_status	= pnv_php_get_adapter_state,
a7da21613c4efc Lukas Wunner      2018-09-08  599  	.get_attention_status	= pnv_php_get_attention_state,
66725152fb9f17 Gavin Shan        2016-05-20  600  	.set_attention_status	= pnv_php_set_attention_state,
66725152fb9f17 Gavin Shan        2016-05-20  601  	.enable_slot		= pnv_php_enable_slot,
66725152fb9f17 Gavin Shan        2016-05-20  602  	.disable_slot		= pnv_php_disable_slot,
7fd1fe4e4811f5 Oliver O'Halloran 2019-09-03 @603  	.reset_slot		= pnv_php_reset_slot,
66725152fb9f17 Gavin Shan        2016-05-20  604  };
66725152fb9f17 Gavin Shan        2016-05-20  605  

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 73386 bytes --]

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism
  2021-07-05 14:21 ` [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
@ 2021-07-06  5:16   ` Leon Romanovsky
  2021-07-11 16:51   ` Raphael Norwitz
  1 sibling, 0 replies; 18+ messages in thread
From: Leon Romanovsky @ 2021-07-06  5:16 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 Mon, Jul 05, 2021 at 07:51:34PM +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>
> ---
>  Documentation/ABI/testing/sysfs-bus-pci |  19 +++++
>  drivers/pci/pci-sysfs.c                 | 103 ++++++++++++++++++++++++
>  2 files changed, 122 insertions(+)
> 

Thanks,
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods
  2021-07-05 14:37   ` Amey Narkhede
@ 2021-07-08 20:24     ` Alex Williamson
  0 siblings, 0 replies; 18+ messages in thread
From: Alex Williamson @ 2021-07-08 20:24 UTC (permalink / raw)
  To: Amey Narkhede
  Cc: Bjorn Helgaas, Raphael Norwitz, linux-pci, linux-kernel, kw,
	Shanker Donthineni, Sinan Kaya, Len Brown, Rafael J . Wysocki

On Mon, 5 Jul 2021 20:07:39 +0530
Amey Narkhede <ameynarkhede03@gmail.com> wrote:

> On 21/07/05 07:51PM, Amey Narkhede wrote:
> > Add has_pcie_flr bitfield in struct pci_dev to indicate support for PCIe
> > FLR to avoid reading PCI_EXP_DEVCAP multiple times.
> >
> > 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                          | 59 +++++++++++-----------
> >  drivers/pci/pcie/aer.c                     | 12 ++---
> >  drivers/pci/probe.c                        |  6 ++-
> >  drivers/pci/quirks.c                       |  9 ++--
> >  include/linux/pci.h                        |  3 +-
> >  6 files changed, 45 insertions(+), 48 deletions(-)
> >
> > diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c  
> [...]
> > index 3a62d09b8..a95252113 100644
> > --- a/drivers/pci/probe.c
> > +++ b/drivers/pci/probe.c
> > @@ -1487,6 +1487,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
> >  {
> >  	int pos;
> >  	u16 reg16;
> > +	u32 reg32;
> >  	int type;
> >  	struct pci_dev *parent;
> >
> > @@ -1497,8 +1498,9 @@ 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, &reg32);
> > +	pdev->pcie_mpss = reg32 & PCI_EXP_DEVCAP_PAYLOAD;
> > +	pdev->has_pcie_flr = reg32 & PCI_EXP_DEVCAP_FLR ? 1 : 0;  
> On the side note, removing ternary here as Alex suggested doesn't work
> for some reason.

Probably I'm just incorrectly extrapolating boolean behavior to
bitfields, but indeed it doesn't work that way.  The other option is to
use the !! trick, ie. has_pcie_flr = !!(reg32 & PCI_EXP_DEVCAP_FLR),
but both solutions are used elsewhere in this file.

Reviewed-by: Alex Williamson <alex.williamson@redhat.com>


^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods
  2021-07-05 14:21 ` [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
  2021-07-05 14:37   ` Amey Narkhede
@ 2021-07-11 16:40   ` Raphael Norwitz
  1 sibling, 0 replies; 18+ messages in thread
From: Raphael Norwitz @ 2021-07-11 16:40 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 Mon, Jul 05, 2021 at 07:51:31PM +0530, Amey Narkhede wrote:
> Add has_pcie_flr bitfield in struct pci_dev to indicate support for PCIe
> FLR to avoid reading PCI_EXP_DEVCAP multiple times.
> 
> 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                          | 59 +++++++++++-----------
>  drivers/pci/pcie/aer.c                     | 12 ++---
>  drivers/pci/probe.c                        |  6 ++-
>  drivers/pci/quirks.c                       |  9 ++--
>  include/linux/pci.h                        |  3 +-
>  6 files changed, 45 insertions(+), 48 deletions(-)
> 
> diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
> index facc8e6bc..15d6c8452 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 452351025..fefa6d7b3 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -4611,32 +4611,12 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev)
>  }
>  EXPORT_SYMBOL(pci_wait_for_pending_transaction);
>  
> -/**
> - * pcie_has_flr - check if a device supports function level resets
> - * @dev: device to check
> - *
> - * Returns true if the device advertises support for PCIe function level
> - * resets.
> - */
> -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;
> -}
> -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)
>  {
> @@ -4659,6 +4639,28 @@ 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 (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
> +		return -ENOTTY;
> +
> +	if (!dev->has_pcie_flr)
> +		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;
> @@ -5139,11 +5141,9 @@ 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;
> @@ -5174,8 +5174,9 @@ 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 ec943cee5..98077595a 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/probe.c b/drivers/pci/probe.c
> index 3a62d09b8..a95252113 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -1487,6 +1487,7 @@ void set_pcie_port_type(struct pci_dev *pdev)
>  {
>  	int pos;
>  	u16 reg16;
> +	u32 reg32;
>  	int type;
>  	struct pci_dev *parent;
>  
> @@ -1497,8 +1498,9 @@ 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, &reg32);
> +	pdev->pcie_mpss = reg32 & PCI_EXP_DEVCAP_PAYLOAD;
> +	pdev->has_pcie_flr = reg32 & PCI_EXP_DEVCAP_FLR ? 1 : 0;
>  
>  	parent = pci_upstream_bridge(pdev);
>  	if (!parent)
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index d85914afe..f977ba79a 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;
> +	int ret = pcie_reset_flr(dev, probe);
>  
>  	if (probe)
> -		return 0;
> -
> -	pcie_flr(dev);
> +		return ret;
>  
>  	msleep(250);
>  
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index c20211e59..d432428fd 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -337,6 +337,7 @@ struct pci_dev {
>  	u8		msi_cap;	/* MSI capability offset */
>  	u8		msix_cap;	/* MSI-X capability offset */
>  	u8		pcie_mpss:3;	/* PCIe Max Payload Size Supported */
> +	u8		has_pcie_flr:1; /* PCIe FLR supported */
>  	u8		rom_base_reg;	/* Config register controlling ROM */
>  	u8		pin;		/* Interrupt pin this device uses */
>  	u16		pcie_flags_reg;	/* Cached PCIe Capabilities Register */
> @@ -1225,7 +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] 18+ messages in thread

* Re: [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of reset methods
  2021-07-05 14:21 ` [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of " Amey Narkhede
@ 2021-07-11 16:42   ` Raphael Norwitz
  2021-07-14 13:13     ` Shanker R Donthineni
  0 siblings, 1 reply; 18+ messages in thread
From: Raphael Norwitz @ 2021-07-11 16:42 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 Mon, Jul 05, 2021 at 07:51:32PM +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   | 92 ++++++++++++++++++++++++++-------------------
>  drivers/pci/pci.h   |  9 ++++-
>  drivers/pci/probe.c |  5 +--
>  include/linux/pci.h |  7 ++++
>  4 files changed, 70 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index fefa6d7b3..42440cb10 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -72,6 +72,14 @@ static void pci_dev_d3_sleep(struct pci_dev *dev)
>  		msleep(delay);
>  }
>  
> +int pci_reset_supported(struct pci_dev *dev)
> +{
> +	u8 null_reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
> +
> +	return memcmp(null_reset_methods,
> +		      dev->reset_methods, sizeof(null_reset_methods));
> +}
> +
>  #ifdef CONFIG_PCI_DOMAINS
>  int pci_domains_supported = 1;
>  #endif
> @@ -5104,6 +5112,15 @@ static void pci_dev_restore(struct pci_dev *dev)
>  		err_handler->reset_done(dev);
>  }
>  
> +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.
> @@ -5126,65 +5143,62 @@ 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 && (m = dev->reset_methods[i]); i++) {
> +		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.
> + * to reads and writes to its PCI config space in order to use this function.
>   *
> - * 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 i, n, rc;
> +	u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
> +
> +	n = 0;
> +
> +	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;
> +	for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
> +		rc = pci_reset_fn_methods[i].reset_fn(dev, 1);
> +		if (!rc)
> +			reset_methods[n++] = i;
> +		else if (rc != -ENOTTY)
> +			break;
> +	}
>  
> -	return pci_reset_bus_function(dev, 1);
> +	memcpy(dev->reset_methods, reset_methods, sizeof(reset_methods));
>  }
>  
>  /**
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 37c913bbc..db1ad94e7 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);
> +int 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 +607,12 @@ 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;
> +};
> +
> +extern const struct pci_reset_fn_method pci_reset_fn_methods[];
>  #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 a95252113..a3e9a9c88 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -2406,9 +2406,8 @@ 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 d432428fd..9f3e85f33 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] 18+ messages in thread

* Re: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism
  2021-07-05 14:21 ` [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
  2021-07-06  5:16   ` Leon Romanovsky
@ 2021-07-11 16:51   ` Raphael Norwitz
  2021-07-14 11:59     ` Amey Narkhede
  1 sibling, 1 reply; 18+ messages in thread
From: Raphael Norwitz @ 2021-07-11 16:51 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 Mon, Jul 05, 2021 at 07:51:34PM +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>

Just some spacing NITs.

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

> ---
>  Documentation/ABI/testing/sysfs-bus-pci |  19 +++++
>  drivers/pci/pci-sysfs.c                 | 103 ++++++++++++++++++++++++
>  2 files changed, 122 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ef00fada2..43f4e33c7 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 comma 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 316f70c3e..8a740e211 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1334,6 +1334,108 @@ static const struct attribute_group pci_dev_rom_attr_group = {
>  	.is_bin_visible = pci_dev_rom_attr_is_visible,
>  };
>  
> +static ssize_t reset_method_show(struct device *dev,

Nit: spaces on the following two lines. "struct device_attribute *attr"
and "char *buf" should be in line with "struct device *dev"

> +				 struct device_attribute *attr,
> +				 char *buf)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	ssize_t len = 0;
> +	int i, idx;
> +
> +	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> +		idx = pdev->reset_methods[i];
> +		if (!idx)
> +			break;
> +
> +		len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "",
> +				     pci_reset_fn_methods[idx].name);
> +	}
> +
> +	if (len)
> +		len += sysfs_emit_at(buf, len, "\n");
> +
> +	return len;
> +}
> +
> +static ssize_t reset_method_store(struct device *dev,

Nit: spaces on the following two lines

> +				  struct device_attribute *attr,
> +				  const char *buf, size_t count)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	int n = 0;
> +	char *name, *options = NULL;
> +	u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
> +
> +	if (count >= (PAGE_SIZE - 1))
> +		return -EINVAL;
> +
> +	if (sysfs_streq(buf, "")) {
> +		pci_warn(pdev, "All device reset methods disabled by user");
> +		goto set_reset_methods;
> +	}
> +
> +	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) {
> +		int i;
> +
> +		if (sysfs_streq(name, ""))
> +			continue;
> +
> +		name = strim(name);
> +
> +		for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
> +			if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
> +			    !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
> +				reset_methods[n++] = i;
> +				break;
> +			}
> +		}
> +
> +		if (i == PCI_NUM_RESET_METHODS) {
> +			kfree(options);
> +			return -EINVAL;
> +		}
> +	}
> +
> +	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
> +		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
> +
> +set_reset_methods:
> +	memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods));
> +	kfree(options);
> +	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,

Nit: ditto - spacing.

> +						    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;
> +}
> +
> +static 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,
> +};
> +
>  static ssize_t reset_store(struct device *dev, struct device_attribute *attr,

Nit: spacing following line.

>  			   const char *buf, size_t count)
>  {
> @@ -1491,6 +1593,7 @@ 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,
> -- 
> 2.32.0
> 
> 

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism
  2021-07-11 16:51   ` Raphael Norwitz
@ 2021-07-14 11:59     ` Amey Narkhede
  0 siblings, 0 replies; 18+ messages in thread
From: Amey Narkhede @ 2021-07-14 11:59 UTC (permalink / raw)
  To: Raphael Norwitz
  Cc: Bjorn Helgaas, Alex Williamson, Raphael Norwitz, linux-pci,
	linux-kernel, kw, Shanker Donthineni, Sinan Kaya, Len Brown,
	Rafael J . Wysocki, Amey Narkhede

On 21/07/11 04:51PM, Raphael Norwitz wrote:
> On Mon, Jul 05, 2021 at 07:51:34PM +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>
>
> Just some spacing NITs.
>
> Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>
>
> > ---
> >  Documentation/ABI/testing/sysfs-bus-pci |  19 +++++
> >  drivers/pci/pci-sysfs.c                 | 103 ++++++++++++++++++++++++
> >  2 files changed, 122 insertions(+)
> >
> > diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> > index ef00fada2..43f4e33c7 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 comma 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 316f70c3e..8a740e211 100644
> > --- a/drivers/pci/pci-sysfs.c
> > +++ b/drivers/pci/pci-sysfs.c
> > @@ -1334,6 +1334,108 @@ static const struct attribute_group pci_dev_rom_attr_group = {
> >  	.is_bin_visible = pci_dev_rom_attr_is_visible,
> >  };
> >
> > +static ssize_t reset_method_show(struct device *dev,
>
> Nit: spaces on the following two lines. "struct device_attribute *attr"
> and "char *buf" should be in line with "struct device *dev"
>
Not sure what happened when creating the patches but on my editor spaces
seems to consistent as you suggested here. For some reason git
format-patch is acting weird.

Thanks,
Amey
> > +				 struct device_attribute *attr,
> > +				 char *buf)
> > +{
> > +	struct pci_dev *pdev = to_pci_dev(dev);
> > +	ssize_t len = 0;
> > +	int i, idx;
> > +
> > +	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> > +		idx = pdev->reset_methods[i];
> > +		if (!idx)
> > +			break;
> > +
> > +		len += sysfs_emit_at(buf, len, "%s%s", len ? "," : "",
> > +				     pci_reset_fn_methods[idx].name);
> > +	}
> > +
> > +	if (len)
> > +		len += sysfs_emit_at(buf, len, "\n");
> > +
> > +	return len;
> > +}
> > +
> > +static ssize_t reset_method_store(struct device *dev,
>
> Nit: spaces on the following two lines
>
> > +				  struct device_attribute *attr,
> > +				  const char *buf, size_t count)
> > +{
> > +	struct pci_dev *pdev = to_pci_dev(dev);
> > +	int n = 0;
> > +	char *name, *options = NULL;
> > +	u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 };
> > +
> > +	if (count >= (PAGE_SIZE - 1))
> > +		return -EINVAL;
> > +
> > +	if (sysfs_streq(buf, "")) {
> > +		pci_warn(pdev, "All device reset methods disabled by user");
> > +		goto set_reset_methods;
> > +	}
> > +
> > +	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) {
> > +		int i;
> > +
> > +		if (sysfs_streq(name, ""))
> > +			continue;
> > +
> > +		name = strim(name);
> > +
> > +		for (i = 1; i < PCI_NUM_RESET_METHODS; i++) {
> > +			if (sysfs_streq(name, pci_reset_fn_methods[i].name) &&
> > +			    !pci_reset_fn_methods[i].reset_fn(pdev, 1)) {
> > +				reset_methods[n++] = i;
> > +				break;
> > +			}
> > +		}
> > +
> > +		if (i == PCI_NUM_RESET_METHODS) {
> > +			kfree(options);
> > +			return -EINVAL;
> > +		}
> > +	}
> > +
> > +	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && reset_methods[0] != 1)
> > +		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
> > +
> > +set_reset_methods:
> > +	memcpy(pdev->reset_methods, reset_methods, sizeof(reset_methods));
> > +	kfree(options);
> > +	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,
>
> Nit: ditto - spacing.
>
> > +						    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;
> > +}
> > +
> > +static 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,
> > +};
> > +
> >  static ssize_t reset_store(struct device *dev, struct device_attribute *attr,
>
> Nit: spacing following line.
>
> >  			   const char *buf, size_t count)
> >  {
> > @@ -1491,6 +1593,7 @@ 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,
> > --
> > 2.32.0
> >
> >

^ permalink raw reply	[flat|nested] 18+ messages in thread

* Re: [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of reset methods
  2021-07-11 16:42   ` Raphael Norwitz
@ 2021-07-14 13:13     ` Shanker R Donthineni
  0 siblings, 0 replies; 18+ messages in thread
From: Shanker R Donthineni @ 2021-07-14 13:13 UTC (permalink / raw)
  To: Raphael Norwitz, Amey Narkhede
  Cc: Bjorn Helgaas, alex.williamson, linux-pci, linux-kernel, kw,
	Sinan Kaya, Len Brown, Rafael J . Wysocki

Hi Raphael,

On 7/11/21 11:42 AM, Raphael Norwitz wrote:
> On Mon, Jul 05, 2021 at 07:51:32PM +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>
>

Please review the latest v10 patch series.

^ permalink raw reply	[flat|nested] 18+ messages in thread

end of thread, other threads:[~2021-07-14 13:14 UTC | newest]

Thread overview: 18+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-07-05 14:21 [PATCH v9 0/8] Expose and manage PCI device reset Amey Narkhede
2021-07-05 14:21 ` [PATCH v9 1/8] PCI: Add pcie_reset_flr to follow calling convention of other reset methods Amey Narkhede
2021-07-05 14:37   ` Amey Narkhede
2021-07-08 20:24     ` Alex Williamson
2021-07-11 16:40   ` Raphael Norwitz
2021-07-05 14:21 ` [PATCH v9 2/8] PCI: Add new array for keeping track of ordering of " Amey Narkhede
2021-07-11 16:42   ` Raphael Norwitz
2021-07-14 13:13     ` Shanker R Donthineni
2021-07-05 14:21 ` [PATCH v9 3/8] PCI: Remove reset_fn field from pci_dev Amey Narkhede
2021-07-05 14:21 ` [PATCH v9 4/8] PCI/sysfs: Allow userspace to query and set device reset mechanism Amey Narkhede
2021-07-06  5:16   ` Leon Romanovsky
2021-07-11 16:51   ` Raphael Norwitz
2021-07-14 11:59     ` Amey Narkhede
2021-07-05 14:21 ` [PATCH v9 5/8] PCI: Define a function to set ACPI_COMPANION in pci_dev Amey Narkhede
2021-07-05 14:21 ` [PATCH v9 6/8] PCI: Setup ACPI fwnode early and at the same time with OF Amey Narkhede
2021-07-05 14:21 ` [PATCH v9 7/8] PCI: Add support for ACPI _RST reset method Amey Narkhede
2021-07-05 14:21 ` [PATCH v9 8/8] PCI: Change the type of probe argument in reset functions Amey Narkhede
2021-07-05 23:39   ` kernel test robot

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