[PATCH v13 0/9] PCI: Expose and manage PCI device reset

[PATCH v13 0/9] PCI: Expose and manage PCI device reset

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

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

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

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

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

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

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

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

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

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

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

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

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

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

 Documentation/ABI/testing/sysfs-bus-pci       |  19 ++
 drivers/crypto/cavium/nitrox/nitrox_main.c    |   4 +-
 .../ethernet/cavium/liquidio/lio_vf_main.c    |   2 +-
 drivers/pci/hotplug/pciehp.h                  |   2 +-
 drivers/pci/hotplug/pciehp_hpc.c              |   4 +-
 drivers/pci/hotplug/pnv_php.c                 |   4 +-
 drivers/pci/pci-acpi.c                        |  35 ++-
 drivers/pci/pci-sysfs.c                       |   3 +-
 drivers/pci/pci.c                             | 290 +++++++++++++-----
 drivers/pci/pci.h                             |  24 +-
 drivers/pci/pcie/aer.c                        |  12 +-
 drivers/pci/probe.c                           |  16 +-
 drivers/pci/quirks.c                          |  39 ++-
 drivers/pci/remove.c                          |   1 -
 include/linux/pci.h                           |  14 +-
 include/linux/pci_hotplug.h                   |   2 +-
 16 files changed, 336 insertions(+), 135 deletions(-)

--
2.32.0

[PATCH v13 1/9] PCI: Cache PCIe FLR capability

[Amey Narkhede]

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

Refactor pcie_has_flr() to use cached device capabilities.

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

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

[PATCH v13 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods

[Amey Narkhede]

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

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

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index facc8e6bc580..15d6c8452807 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_main.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
@@ -306,9 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
 		return -ENOMEM;
 	}
 
-	/* check flr support */
-	if (pcie_has_flr(pdev))
-		pcie_flr(pdev);
+	pcie_reset_flr(pdev, 0);
 
 	pci_restore_state(pdev);
 
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 1fafd05caa41..f219a3dc6750 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4626,15 +4626,13 @@ bool pcie_has_flr(struct pci_dev *dev)
 
 	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
 }
-EXPORT_SYMBOL_GPL(pcie_has_flr);
 
 /**
  * pcie_flr - initiate a PCIe function level reset
  * @dev: device to reset
  *
- * Initiate a function level reset on @dev.  The caller should ensure the
- * device supports FLR before calling this function, e.g. by using the
- * pcie_has_flr() helper.
+ * Initiate a function level reset unconditionally on @dev without
+ * checking any flags and DEVCAP
  */
 int pcie_flr(struct pci_dev *dev)
 {
@@ -4655,7 +4653,26 @@ int pcie_flr(struct pci_dev *dev)
 
 	return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
 }
-EXPORT_SYMBOL_GPL(pcie_flr);
+EXPORT_SYMBOL(pcie_flr);
+
+/**
+ * pcie_reset_flr - initiate a PCIe function level reset
+ * @dev: device to reset
+ * @probe: If set, only check if the device can be reset this way.
+ *
+ * Initiate a function level reset on @dev.
+ */
+int pcie_reset_flr(struct pci_dev *dev, int probe)
+{
+	if (!pcie_has_flr(dev))
+		return -ENOTTY;
+
+	if (probe)
+		return 0;
+
+	return pcie_flr(dev);
+}
+EXPORT_SYMBOL_GPL(pcie_reset_flr);
 
 static int pci_af_flr(struct pci_dev *dev, int probe)
 {
@@ -5137,11 +5154,9 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 	rc = pci_dev_specific_reset(dev, 0);
 	if (rc != -ENOTTY)
 		return rc;
-	if (pcie_has_flr(dev)) {
-		rc = pcie_flr(dev);
-		if (rc != -ENOTTY)
-			return rc;
-	}
+	rc = pcie_reset_flr(dev, 0);
+	if (rc != -ENOTTY)
+		return rc;
 	rc = pci_af_flr(dev, 0);
 	if (rc != -ENOTTY)
 		return rc;
@@ -5172,8 +5187,9 @@ int pci_probe_reset_function(struct pci_dev *dev)
 	rc = pci_dev_specific_reset(dev, 1);
 	if (rc != -ENOTTY)
 		return rc;
-	if (pcie_has_flr(dev))
-		return 0;
+	rc = pcie_reset_flr(dev, 1);
+	if (rc != -ENOTTY)
+		return rc;
 	rc = pci_af_flr(dev, 1);
 	if (rc != -ENOTTY)
 		return rc;
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index ec943cee5ecc..98077595a73e 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1405,13 +1405,11 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	}
 
 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
-		if (pcie_has_flr(dev)) {
-			rc = pcie_flr(dev);
-			pci_info(dev, "has been reset (%d)\n", rc);
-		} else {
-			pci_info(dev, "not reset (no FLR support)\n");
-			rc = -ENOTTY;
-		}
+		rc = pcie_reset_flr(dev, 0);
+		if (!rc)
+			pci_info(dev, "has been reset\n");
+		else
+			pci_info(dev, "not reset (no FLR support: %d)\n", rc);
 	} else {
 		rc = pci_bus_error_reset(dev);
 		pci_info(dev, "%s Port link has been reset (%d)\n",
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index d85914afe65a..b48e7ef8b641 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3819,7 +3819,7 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
 	u32 cfg;
 
 	if (dev->class != PCI_CLASS_STORAGE_EXPRESS ||
-	    !pcie_has_flr(dev) || !pci_resource_start(dev, 0))
+	    pcie_reset_flr(dev, 1) || !pci_resource_start(dev, 0))
 		return -ENOTTY;
 
 	if (probe)
@@ -3888,13 +3888,10 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
  */
 static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
 {
-	if (!pcie_has_flr(dev))
-		return -ENOTTY;
-
 	if (probe)
-		return 0;
+		return pcie_reset_flr(dev, 1);
 
-	pcie_flr(dev);
+	pcie_reset_flr(dev, 0);
 
 	msleep(250);
 
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 697b1f085c7b..aa85e7d3147e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1226,7 +1226,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 			     enum pci_bus_speed *speed,
 			     enum pcie_link_width *width);
 void pcie_print_link_status(struct pci_dev *dev);
-bool pcie_has_flr(struct pci_dev *dev);
+int pcie_reset_flr(struct pci_dev *dev, int probe);
 int pcie_flr(struct pci_dev *dev);
 int __pci_reset_function_locked(struct pci_dev *dev);
 int pci_reset_function(struct pci_dev *dev);
-- 
2.32.0

[PATCH v13 3/9] PCI: Add new array for keeping track of ordering of reset methods

[Amey Narkhede]

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

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

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

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index f219a3dc6750..010962d7dba6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -73,6 +73,11 @@ static void pci_dev_d3_sleep(struct pci_dev *dev)
 		msleep(delay);
 }
 
+bool pci_reset_supported(struct pci_dev *dev)
+{
+	return dev->reset_methods[0] != 0;
+}
+
 #ifdef CONFIG_PCI_DOMAINS
 int pci_domains_supported = 1;
 #endif
@@ -5117,6 +5122,16 @@ static void pci_dev_restore(struct pci_dev *dev)
 		err_handler->reset_done(dev);
 }
 
+/* dev->reset_methods[] is a 0-terminated list of indices into this array */
+static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
+	{ },
+	{ pci_dev_specific_reset, .name = "device_specific" },
+	{ pcie_reset_flr, .name = "flr" },
+	{ pci_af_flr, .name = "af_flr" },
+	{ pci_pm_reset, .name = "pm" },
+	{ pci_reset_bus_function, .name = "bus" },
+};
+
 /**
  * __pci_reset_function_locked - reset a PCI device function while holding
  * the @dev mutex lock.
@@ -5139,65 +5154,65 @@ static void pci_dev_restore(struct pci_dev *dev)
  */
 int __pci_reset_function_locked(struct pci_dev *dev)
 {
-	int rc;
+	int i, m, rc = -ENOTTY;
 
 	might_sleep();
 
 	/*
-	 * A reset method returns -ENOTTY if it doesn't support this device
-	 * and we should try the next method.
+	 * A reset method returns -ENOTTY if it doesn't support this device and
+	 * we should try the next method.
 	 *
-	 * If it returns 0 (success), we're finished.  If it returns any
-	 * other error, we're also finished: this indicates that further
-	 * reset mechanisms might be broken on the device.
+	 * If it returns 0 (success), we're finished.  If it returns any other
+	 * error, we're also finished: this indicates that further reset
+	 * mechanisms might be broken on the device.
 	 */
-	rc = pci_dev_specific_reset(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pcie_reset_flr(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_af_flr(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_pm_reset(dev, 0);
-	if (rc != -ENOTTY)
-		return rc;
-	return pci_reset_bus_function(dev, 0);
+	for (i = 0; i <  PCI_NUM_RESET_METHODS; i++) {
+		m = dev->reset_methods[i];
+		if (!m)
+			return -ENOTTY;
+
+		rc = pci_reset_fn_methods[m].reset_fn(dev, 0);
+		if (!rc)
+			return 0;
+		if (rc != -ENOTTY)
+			return rc;
+	}
+
+	return -ENOTTY;
 }
 EXPORT_SYMBOL_GPL(__pci_reset_function_locked);
 
 /**
- * pci_probe_reset_function - check whether the device can be safely reset
- * @dev: PCI device to reset
+ * pci_init_reset_methods - check whether device can be safely reset
+ * and store supported reset mechanisms.
+ * @dev: PCI device to check for reset mechanisms
  *
  * Some devices allow an individual function to be reset without affecting
- * other functions in the same device.  The PCI device must be responsive
- * to PCI config space in order to use this function.
+ * other functions in the same device.  The PCI device must be in D0-D3hot
+ * state.
  *
- * Returns 0 if the device function can be reset or negative if the
- * device doesn't support resetting a single function.
+ * Stores reset mechanisms supported by device in reset_methods byte array
+ * which is a member of struct pci_dev.
  */
-int pci_probe_reset_function(struct pci_dev *dev)
+void pci_init_reset_methods(struct pci_dev *dev)
 {
-	int rc;
+	int m, i, rc;
+
+	BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS);
 
 	might_sleep();
 
-	rc = pci_dev_specific_reset(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pcie_reset_flr(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_af_flr(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
-	rc = pci_pm_reset(dev, 1);
-	if (rc != -ENOTTY)
-		return rc;
+	i = 0;
+
+	for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
+		rc = pci_reset_fn_methods[m].reset_fn(dev, 1);
+		if (!rc)
+			dev->reset_methods[i++] = m;
+		else if (rc != -ENOTTY)
+			break;
+	}
 
-	return pci_reset_bus_function(dev, 1);
+	dev->reset_methods[i] = 0;
 }
 
 /**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 37c913bbc6e1..7438953745e0 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -33,7 +33,8 @@ enum pci_mmap_api {
 int pci_mmap_fits(struct pci_dev *pdev, int resno, struct vm_area_struct *vmai,
 		  enum pci_mmap_api mmap_api);
 
-int pci_probe_reset_function(struct pci_dev *dev);
+bool pci_reset_supported(struct pci_dev *dev);
+void pci_init_reset_methods(struct pci_dev *dev);
 int pci_bridge_secondary_bus_reset(struct pci_dev *dev);
 int pci_bus_error_reset(struct pci_dev *dev);
 
@@ -606,6 +607,11 @@ struct pci_dev_reset_methods {
 	int (*reset)(struct pci_dev *dev, int probe);
 };
 
+struct pci_reset_fn_method {
+	int (*reset_fn)(struct pci_dev *pdev, int probe);
+	char *name;
+};
+
 #ifdef CONFIG_PCI_QUIRKS
 int pci_dev_specific_reset(struct pci_dev *dev, int probe);
 #else
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index df3f9db6e151..5d8ad230f7d0 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2405,9 +2405,8 @@ static void pci_init_capabilities(struct pci_dev *dev)
 	pci_rcec_init(dev);		/* Root Complex Event Collector */
 
 	pcie_report_downtraining(dev);
-
-	if (pci_probe_reset_function(dev) == 0)
-		dev->reset_fn = 1;
+	pci_init_reset_methods(dev);
+	dev->reset_fn = pci_reset_supported(dev);
 }
 
 /*
diff --git a/include/linux/pci.h b/include/linux/pci.h
index aa85e7d3147e..d1a9a232d08e 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -49,6 +49,9 @@
 			       PCI_STATUS_SIG_TARGET_ABORT | \
 			       PCI_STATUS_PARITY)
 
+/* Number of reset methods used in pci_reset_fn_methods array in pci.c */
+#define PCI_NUM_RESET_METHODS 6
+
 /*
  * The PCI interface treats multi-function devices as independent
  * devices.  The slot/function address of each device is encoded
@@ -506,6 +509,10 @@ struct pci_dev {
 	char		*driver_override; /* Driver name to force a match */
 
 	unsigned long	priv_flags;	/* Private flags for the PCI driver */
+	/*
+	 * See pci_reset_fn_methods array in pci.c for ordering.
+	 */
+	u8 reset_methods[PCI_NUM_RESET_METHODS];	/* Reset methods ordered by priority */
 };
 
 static inline struct pci_dev *pci_physfn(struct pci_dev *dev)
-- 
2.32.0

[PATCH v13 4/9] PCI: Remove reset_fn field from pci_dev

[Amey Narkhede]

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

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

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

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 516f166ceff8..336d149ee2e2 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -526,7 +526,7 @@ static void octeon_destroy_resources(struct octeon_device *oct)
 			oct->irq_name_storage = NULL;
 		}
 		/* Soft reset the octeon device before exiting */
-		if (oct->pci_dev->reset_fn)
+		if (!pcie_reset_flr(oct->pci_dev, 1))
 			octeon_pci_flr(oct);
 		else
 			cn23xx_vf_ask_pf_to_do_flr(oct);
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index beb8d1f4fafe..316f70c3e3b4 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1367,7 +1367,7 @@ static umode_t pci_dev_reset_attr_is_visible(struct kobject *kobj,
 {
 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
 
-	if (!pdev->reset_fn)
+	if (!pci_reset_supported(pdev))
 		return 0;
 
 	return a->mode;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 010962d7dba6..932dd21e759b 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5235,7 +5235,7 @@ int pci_reset_function(struct pci_dev *dev)
 {
 	int rc;
 
-	if (!dev->reset_fn)
+	if (!pci_reset_supported(dev))
 		return -ENOTTY;
 
 	pci_dev_lock(dev);
@@ -5271,7 +5271,7 @@ int pci_reset_function_locked(struct pci_dev *dev)
 {
 	int rc;
 
-	if (!dev->reset_fn)
+	if (!pci_reset_supported(dev))
 		return -ENOTTY;
 
 	pci_dev_save_and_disable(dev);
@@ -5294,7 +5294,7 @@ int pci_try_reset_function(struct pci_dev *dev)
 {
 	int rc;
 
-	if (!dev->reset_fn)
+	if (!pci_reset_supported(dev))
 		return -ENOTTY;
 
 	if (!pci_dev_trylock(dev))
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 5d8ad230f7d0..379e85037d9b 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2406,7 +2406,6 @@ static void pci_init_capabilities(struct pci_dev *dev)
 
 	pcie_report_downtraining(dev);
 	pci_init_reset_methods(dev);
-	dev->reset_fn = pci_reset_supported(dev);
 }
 
 /*
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index b48e7ef8b641..0db5dac3ddce 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5589,7 +5589,7 @@ static void quirk_reset_lenovo_thinkpad_p50_nvgpu(struct pci_dev *pdev)
 
 	if (pdev->subsystem_vendor != PCI_VENDOR_ID_LENOVO ||
 	    pdev->subsystem_device != 0x222e ||
-	    !pdev->reset_fn)
+	    !pci_reset_supported(pdev))
 		return;
 
 	if (pci_enable_device_mem(pdev))
diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c
index dd12c2fcc7dc..4c54c75050dc 100644
--- a/drivers/pci/remove.c
+++ b/drivers/pci/remove.c
@@ -19,7 +19,6 @@ static void pci_stop_dev(struct pci_dev *dev)
 	pci_pme_active(dev, false);
 
 	if (pci_dev_is_added(dev)) {
-		dev->reset_fn = 0;
 
 		device_release_driver(&dev->dev);
 		pci_proc_detach_device(dev);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index d1a9a232d08e..94d74fd594c1 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -431,7 +431,6 @@ struct pci_dev {
 	unsigned int	state_saved:1;
 	unsigned int	is_physfn:1;
 	unsigned int	is_virtfn:1;
-	unsigned int	reset_fn:1;
 	unsigned int	is_hotplug_bridge:1;
 	unsigned int	shpc_managed:1;		/* SHPC owned by shpchp */
 	unsigned int	is_thunderbolt:1;	/* Thunderbolt controller */
-- 
2.32.0

[PATCH v13 5/9] PCI: Allow userspace to query and set device reset mechanism

[Amey Narkhede]

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

Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 Documentation/ABI/testing/sysfs-bus-pci |  19 +++++
 drivers/pci/pci-sysfs.c                 |   1 +
 drivers/pci/pci.c                       | 105 ++++++++++++++++++++++++
 drivers/pci/pci.h                       |   2 +
 4 files changed, 127 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
index ef00fada2efb..ef66b62bf025 100644
--- a/Documentation/ABI/testing/sysfs-bus-pci
+++ b/Documentation/ABI/testing/sysfs-bus-pci
@@ -121,6 +121,25 @@ Description:
 		child buses, and re-discover devices removed earlier
 		from this part of the device tree.
 
+What:		/sys/bus/pci/devices/.../reset_method
+Date:		March 2021
+Contact:	Amey Narkhede <ameynarkhede03@gmail.com>
+Description:
+		Some devices allow an individual function to be reset
+		without affecting other functions in the same slot.
+
+		For devices that have this support, a file named
+		reset_method will be present in sysfs. Initially reading
+		this file will give names of the device supported reset
+		methods and their ordering. After write, this file will
+		give names and ordering of currently enabled reset methods.
+		Writing the name or space separated list of names of any of
+		the device supported reset methods to this file will set
+		the reset methods and their ordering to be used when
+		resetting the device. Writing empty string to this file
+		will disable ability to reset the device and writing
+		"default" will return to the original value.
+
 What:		/sys/bus/pci/devices/.../reset
 Date:		July 2009
 Contact:	Michael S. Tsirkin <mst@redhat.com>
diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 316f70c3e3b4..54ee7193b463 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -1491,6 +1491,7 @@ const struct attribute_group *pci_dev_groups[] = {
 	&pci_dev_config_attr_group,
 	&pci_dev_rom_attr_group,
 	&pci_dev_reset_attr_group,
+	&pci_dev_reset_method_attr_group,
 	&pci_dev_vpd_attr_group,
 #ifdef CONFIG_DMI
 	&pci_dev_smbios_attr_group,
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 932dd21e759b..c496cd164aca 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5132,6 +5132,111 @@ static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
 	{ pci_reset_bus_function, .name = "bus" },
 };
 
+static ssize_t reset_method_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	ssize_t len = 0;
+	int i, m;
+
+	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
+		m = pdev->reset_methods[i];
+		if (!m)
+			break;
+
+		len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
+				     pci_reset_fn_methods[m].name);
+	}
+
+	if (len)
+		len += sysfs_emit_at(buf, len, "\n");
+
+	return len;
+}
+
+static ssize_t reset_method_store(struct device *dev,
+				  struct device_attribute *attr,
+				  const char *buf, size_t count)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	int i = 0;
+	char *name, *options = NULL;
+
+	if (count >= (PAGE_SIZE - 1))
+		return -EINVAL;
+
+	if (sysfs_streq(buf, "")) {
+		pdev->reset_methods[0] = 0;
+		pci_warn(pdev, "All device reset methods disabled by user");
+		return count;
+	}
+
+	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 m;
+
+		if (sysfs_streq(name, ""))
+			continue;
+
+		name = strim(name);
+
+		for (m = 1; m < PCI_NUM_RESET_METHODS && i < PCI_NUM_RESET_METHODS; m++) {
+			if (sysfs_streq(name, pci_reset_fn_methods[m].name) &&
+			    !pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
+				pdev->reset_methods[i++] = m;
+				break;
+			}
+		}
+
+		if (m == PCI_NUM_RESET_METHODS) {
+			kfree(options);
+			return -EINVAL;
+
+		}
+	}
+
+	if (i < PCI_NUM_RESET_METHODS)
+		pdev->reset_methods[i] = 0;
+
+	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && pdev->reset_methods[0] != 1)
+		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
+
+	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;
+}
+
+const struct attribute_group pci_dev_reset_method_attr_group = {
+	.attrs = pci_dev_reset_method_attrs,
+	.is_visible = pci_dev_reset_method_attr_is_visible,
+};
+
 /**
  * __pci_reset_function_locked - reset a PCI device function while holding
  * the @dev mutex lock.
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 7438953745e0..31458d48eda7 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -714,4 +714,6 @@ static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 extern const struct attribute_group aspm_ctrl_attr_group;
 #endif
 
+extern const struct attribute_group pci_dev_reset_method_attr_group;
+
 #endif /* DRIVERS_PCI_H */
-- 
2.32.0

[PATCH v13 6/9] PCI: Define a function to set ACPI_COMPANION in pci_dev

[Amey Narkhede]

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

[PATCH v13 7/9] PCI: Setup ACPI fwnode early and at the same time with OF

[Amey Narkhede]

From: Shanker Donthineni <sdonthineni@nvidia.com>

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

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

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

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

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

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

[PATCH v13 8/9] PCI: Add support for ACPI _RST reset method

[Amey Narkhede]

From: Shanker Donthineni <sdonthineni@nvidia.com>

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

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

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

diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index dae021322b3f..31f76746741f 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -941,6 +941,29 @@ void pci_set_acpi_fwnode(struct pci_dev *dev)
 				   acpi_pci_find_companion(&dev->dev));
 }

+/**
+ * pci_dev_acpi_reset - do a function level reset using _RST method
+ * @dev: device to reset
+ * @probe: check if _RST method is included in the acpi_device context.
+ */
+int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+{
+	acpi_handle handle = ACPI_HANDLE(&dev->dev);
+
+	if (!handle || !acpi_has_method(handle, "_RST"))
+		return -ENOTTY;
+
+	if (probe)
+		return 0;
+
+	if (ACPI_FAILURE(acpi_evaluate_object(handle, "_RST", NULL, NULL))) {
+		pci_warn(dev, "ACPI _RST failed\n");
+		return -ENOTTY;
+	}
+
+	return 0;
+}
+
 static bool acpi_pci_bridge_d3(struct pci_dev *dev)
 {
 	const struct fwnode_handle *fwnode;
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index c496cd164aca..36121b1fbcab 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5126,6 +5126,7 @@ static void pci_dev_restore(struct pci_dev *dev)
 static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
 	{ },
 	{ pci_dev_specific_reset, .name = "device_specific" },
+	{ pci_dev_acpi_reset, .name = "acpi" },
 	{ pcie_reset_flr, .name = "flr" },
 	{ pci_af_flr, .name = "af_flr" },
 	{ pci_pm_reset, .name = "pm" },
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 8ef379b6cfad..b13dae3323da 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -704,7 +704,13 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
 int pci_acpi_program_hp_params(struct pci_dev *dev);
 extern const struct attribute_group pci_dev_acpi_attr_group;
 void pci_set_acpi_fwnode(struct pci_dev *dev);
+int pci_dev_acpi_reset(struct pci_dev *dev, int probe);
 #else
+static inline int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+{
+	return -ENOTTY;
+}
+
 static inline void pci_set_acpi_fwnode(struct pci_dev *dev) {}
 static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
 {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 94d74fd594c1..d3b06bfd8b99 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -50,7 +50,7 @@
 			       PCI_STATUS_PARITY)

 /* Number of reset methods used in pci_reset_fn_methods array in pci.c */
-#define PCI_NUM_RESET_METHODS 6
+#define PCI_NUM_RESET_METHODS 7

 /*
  * The PCI interface treats multi-function devices as independent
--
2.32.0

[PATCH v13 9/9] PCI: Change the type of probe argument in reset functions

[Amey Narkhede]

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

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Suggested-by: Krzysztof Wilczyński <kw@linux.com>
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
---
 drivers/crypto/cavium/nitrox/nitrox_main.c    |  2 +-
 .../ethernet/cavium/liquidio/lio_vf_main.c    |  2 +-
 drivers/pci/hotplug/pciehp.h                  |  2 +-
 drivers/pci/hotplug/pciehp_hpc.c              |  4 +-
 drivers/pci/hotplug/pnv_php.c                 |  4 +-
 drivers/pci/pci-acpi.c                        |  7 +-
 drivers/pci/pci.c                             | 69 ++++++++++---------
 drivers/pci/pci.h                             | 12 ++--
 drivers/pci/pcie/aer.c                        |  2 +-
 drivers/pci/quirks.c                          | 34 ++++-----
 include/linux/pci.h                           |  5 +-
 include/linux/pci_hotplug.h                   |  2 +-
 12 files changed, 75 insertions(+), 70 deletions(-)

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index 15d6c8452807..f97fa8e997b5 100644
--- a/drivers/crypto/cavium/nitrox/nitrox_main.c
+++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
@@ -306,7 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
 		return -ENOMEM;
 	}
 
-	pcie_reset_flr(pdev, 0);
+	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
 
 	pci_restore_state(pdev);
 
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
index 336d149ee2e2..6e666be6907a 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
@@ -526,7 +526,7 @@ static void octeon_destroy_resources(struct octeon_device *oct)
 			oct->irq_name_storage = NULL;
 		}
 		/* Soft reset the octeon device before exiting */
-		if (!pcie_reset_flr(oct->pci_dev, 1))
+		if (!pcie_reset_flr(oct->pci_dev, PCI_RESET_PROBE))
 			octeon_pci_flr(oct);
 		else
 			cn23xx_vf_ask_pf_to_do_flr(oct);
diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
index 4fd200d8b0a9..f12e1ef9f183 100644
--- a/drivers/pci/hotplug/pciehp.h
+++ b/drivers/pci/hotplug/pciehp.h
@@ -181,7 +181,7 @@ void pciehp_release_ctrl(struct controller *ctrl);
 
 int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
 int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
-int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
+int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool 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 fb3840e222ad..ba1b3e742792 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, bool 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/hotplug/pnv_php.c b/drivers/pci/hotplug/pnv_php.c
index 04565162a449..0e8686a98f2b 100644
--- a/drivers/pci/hotplug/pnv_php.c
+++ b/drivers/pci/hotplug/pnv_php.c
@@ -526,7 +526,7 @@ static int pnv_php_enable(struct pnv_php_slot *php_slot, bool rescan)
 	return 0;
 }
 
-static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
+static int pnv_php_reset_slot(struct hotplug_slot *slot, bool mode)
 {
 	struct pnv_php_slot *php_slot = to_pnv_php_slot(slot);
 	struct pci_dev *bridge = php_slot->pdev;
@@ -537,7 +537,7 @@ static int pnv_php_reset_slot(struct hotplug_slot *slot, int probe)
 	 * which don't have a bridge. Only claim to support
 	 * reset_slot() if we have a bridge device (for now...)
 	 */
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return !bridge;
 
 	/* mask our interrupt while resetting the bridge */
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index 31f76746741f..c88fbcb0c80a 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -944,16 +944,17 @@ void pci_set_acpi_fwnode(struct pci_dev *dev)
 /**
  * pci_dev_acpi_reset - do a function level reset using _RST method
  * @dev: device to reset
- * @probe: check if _RST method is included in the acpi_device context.
+ * @probe: If PCI_RESET_PROBE, check whether _RST method is included
+ *         in the acpi_device context.
  */
-int pci_dev_acpi_reset(struct pci_dev *dev, int probe)
+int pci_dev_acpi_reset(struct pci_dev *dev, bool mode)
 {
 	acpi_handle handle = ACPI_HANDLE(&dev->dev);
 
 	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.c b/drivers/pci/pci.c
index 36121b1fbcab..9a1d792d8c8a 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4663,23 +4663,23 @@ EXPORT_SYMBOL(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, bool mode)
 {
 	if (!pcie_has_flr(dev))
 		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, bool mode)
 {
 	int pos;
 	u8 cap;
@@ -4695,7 +4695,7 @@ 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;
 
 	/*
@@ -4726,7 +4726,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
 /**
  * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0.
  * @dev: Device to reset.
- * @probe: If set, only check if the device can be reset this way.
+ * @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
@@ -4738,7 +4738,7 @@ static int pci_af_flr(struct pci_dev *dev, int probe)
  * by default (i.e. unless the @dev's d3hot_delay field has a different value).
  * Moreover, only devices in D0 can be reset by this function.
  */
-static int pci_pm_reset(struct pci_dev *dev, int probe)
+static int pci_pm_reset(struct pci_dev *dev, bool mode)
 {
 	u16 csr;
 
@@ -4749,7 +4749,7 @@ static int pci_pm_reset(struct pci_dev *dev, int probe)
 	if (csr & PCI_PM_CTRL_NO_SOFT_RESET)
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	if (dev->current_state != PCI_D0)
@@ -4998,7 +4998,7 @@ int pci_bridge_secondary_bus_reset(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset);
 
-static int pci_parent_bus_reset(struct pci_dev *dev, int probe)
+static int pci_parent_bus_reset(struct pci_dev *dev, bool mode)
 {
 	struct pci_dev *pdev;
 
@@ -5010,13 +5010,13 @@ 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, bool mode)
 {
 	int rc = -ENOTTY;
 
@@ -5024,30 +5024,30 @@ static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, int probe)
 		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, bool 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, bool 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)
@@ -5192,7 +5192,7 @@ static ssize_t reset_method_store(struct device *dev,
 
 		for (m = 1; m < PCI_NUM_RESET_METHODS && i < PCI_NUM_RESET_METHODS; m++) {
 			if (sysfs_streq(name, pci_reset_fn_methods[m].name) &&
-			    !pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
+			    !pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) {
 				pdev->reset_methods[i++] = m;
 				break;
 			}
@@ -5208,7 +5208,8 @@ static ssize_t reset_method_store(struct device *dev,
 	if (i < PCI_NUM_RESET_METHODS)
 		pdev->reset_methods[i] = 0;
 
-	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && pdev->reset_methods[0] != 1)
+	if (!pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE) &&
+	    pdev->reset_methods[0] != 1)
 		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
 
 	kfree(options);
@@ -5277,7 +5278,7 @@ int __pci_reset_function_locked(struct pci_dev *dev)
 		if (!m)
 			return -ENOTTY;
 
-		rc = pci_reset_fn_methods[m].reset_fn(dev, 0);
+		rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET);
 		if (!rc)
 			return 0;
 		if (rc != -ENOTTY)
@@ -5311,7 +5312,7 @@ void pci_init_reset_methods(struct pci_dev *dev)
 	i = 0;
 
 	for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
-		rc = pci_reset_fn_methods[m].reset_fn(dev, 1);
+		rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_PROBE);
 		if (!rc)
 			dev->reset_methods[i++] = m;
 		else if (rc != -ENOTTY)
@@ -5628,21 +5629,21 @@ static void pci_slot_restore_locked(struct pci_slot *slot)
 	}
 }
 
-static int pci_slot_reset(struct pci_slot *slot, int probe)
+static int pci_slot_reset(struct pci_slot *slot, bool mode)
 {
 	int rc;
 
 	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;
@@ -5656,7 +5657,7 @@ 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);
 
@@ -5679,14 +5680,14 @@ 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
@@ -5695,14 +5696,14 @@ static int __pci_reset_slot(struct pci_slot *slot)
 	return rc;
 }
 
-static int pci_bus_reset(struct pci_bus *bus, int probe)
+static int pci_bus_reset(struct pci_bus *bus, bool mode)
 {
 	int ret;
 
 	if (!bus->self || !pci_bus_resetable(bus))
 		return -ENOTTY;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	pci_bus_lock(bus);
@@ -5741,14 +5742,14 @@ 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);
 }
 
 /**
@@ -5759,7 +5760,7 @@ 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);
 
@@ -5773,7 +5774,7 @@ static int __pci_reset_bus(struct pci_bus *bus)
 {
 	int rc;
 
-	rc = pci_bus_reset(bus, 1);
+	rc = pci_bus_reset(bus, PCI_RESET_PROBE);
 	if (rc)
 		return rc;
 
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b13dae3323da..8e1ba7bec362 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -604,18 +604,18 @@ static inline int pci_enable_ptm(struct pci_dev *dev, u8 *granularity)
 struct pci_dev_reset_methods {
 	u16 vendor;
 	u16 device;
-	int (*reset)(struct pci_dev *dev, int probe);
+	int (*reset)(struct pci_dev *dev, bool mode);
 };
 
 struct pci_reset_fn_method {
-	int (*reset_fn)(struct pci_dev *pdev, int probe);
+	int (*reset_fn)(struct pci_dev *pdev, bool mode);
 	char *name;
 };
 
 #ifdef CONFIG_PCI_QUIRKS
-int pci_dev_specific_reset(struct pci_dev *dev, int probe);
+int pci_dev_specific_reset(struct pci_dev *dev, bool 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, bool mode)
 {
 	return -ENOTTY;
 }
@@ -704,9 +704,9 @@ static inline int pci_aer_raw_clear_status(struct pci_dev *dev) { return -EINVAL
 int pci_acpi_program_hp_params(struct pci_dev *dev);
 extern const struct attribute_group pci_dev_acpi_attr_group;
 void pci_set_acpi_fwnode(struct pci_dev *dev);
-int pci_dev_acpi_reset(struct pci_dev *dev, int probe);
+int pci_dev_acpi_reset(struct pci_dev *dev, bool 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, bool mode)
 {
 	return -ENOTTY;
 }
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 98077595a73e..cfa7a177500b 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1405,7 +1405,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev)
 	}
 
 	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {
-		rc = pcie_reset_flr(dev, 0);
+		rc = pcie_reset_flr(dev, PCI_RESET_DO_RESET);
 		if (!rc)
 			pci_info(dev, "has been reset\n");
 		else
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 0db5dac3ddce..ad062682a16d 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3669,7 +3669,7 @@ DECLARE_PCI_FIXUP_SUSPEND_LATE(PCI_VENDOR_ID_INTEL,
  * reset a single function if other methods (e.g. FLR, PM D0->D3) are
  * not available.
  */
-static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, int probe)
+static int reset_intel_82599_sfp_virtfn(struct pci_dev *dev, bool 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, bool 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, bool 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, bool 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));
@@ -3886,12 +3886,12 @@ static int nvme_disable_and_flr(struct pci_dev *dev, int probe)
  * device too soon after FLR.  A 250ms delay after FLR has heuristically
  * proven to produce reliably working results for device assignment cases.
  */
-static int delay_250ms_after_flr(struct pci_dev *dev, int probe)
+static int delay_250ms_after_flr(struct pci_dev *dev, bool mode)
 {
-	if (probe)
-		return pcie_reset_flr(dev, 1);
+	if (mode == PCI_RESET_PROBE)
+		return pcie_reset_flr(dev, PCI_RESET_PROBE);
 
-	pcie_reset_flr(dev, 0);
+	pcie_reset_flr(dev, PCI_RESET_DO_RESET);
 
 	msleep(250);
 
@@ -3906,13 +3906,13 @@ 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, bool mode)
 {
 	unsigned long timeout;
 	void __iomem *bar;
 	u32 val;
 
-	if (probe)
+	if (mode == PCI_RESET_PROBE)
 		return 0;
 
 	bar = pci_iomap(pdev, 0, 0);
@@ -3983,7 +3983,7 @@ static const struct pci_dev_reset_methods pci_dev_reset_methods[] = {
  * because when a host assigns a device to a guest VM, the host may need
  * to reset the device but probably doesn't have a driver for it.
  */
-int pci_dev_specific_reset(struct pci_dev *dev, int probe)
+int pci_dev_specific_reset(struct pci_dev *dev, bool mode)
 {
 	const struct pci_dev_reset_methods *i;
 
@@ -3992,7 +3992,7 @@ int pci_dev_specific_reset(struct pci_dev *dev, int probe)
 		     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 d3b06bfd8b99..3e3074c7b8ec 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -52,6 +52,9 @@
 /* Number of reset methods used in pci_reset_fn_methods array in pci.c */
 #define PCI_NUM_RESET_METHODS 7
 
+#define	PCI_RESET_PROBE		true
+#define PCI_RESET_DO_RESET	false
+
 /*
  * The PCI interface treats multi-function devices as independent
  * devices.  The slot/function address of each device is encoded
@@ -1232,7 +1235,7 @@ u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev,
 			     enum pci_bus_speed *speed,
 			     enum pcie_link_width *width);
 void pcie_print_link_status(struct pci_dev *dev);
-int pcie_reset_flr(struct pci_dev *dev, int probe);
+int pcie_reset_flr(struct pci_dev *dev, bool 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 b482e42d7153..eb10dca8c316 100644
--- a/include/linux/pci_hotplug.h
+++ b/include/linux/pci_hotplug.h
@@ -44,7 +44,7 @@ struct hotplug_slot_ops {
 	int (*get_attention_status)	(struct hotplug_slot *slot, u8 *value);
 	int (*get_latch_status)		(struct hotplug_slot *slot, u8 *value);
 	int (*get_adapter_status)	(struct hotplug_slot *slot, u8 *value);
-	int (*reset_slot)		(struct hotplug_slot *slot, int probe);
+	int (*reset_slot)		(struct hotplug_slot *slot, bool mode);
 };
 
 /**
-- 
2.32.0

Re: [PATCH v13 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 5623 bytes --]

Hi Amey,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on pci/next]
[also build test WARNING on pm/linux-next cryptodev/master crypto/master linus/master v5.14-rc3 next-20210730]
[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/PCI-Expose-and-manage-PCI-device-reset/20210801-222806
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: i386-randconfig-s002-20210801 (attached as .config)
compiler: gcc-10 (Ubuntu 10.3.0-1ubuntu1~20.04) 10.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.3-341-g8af24329-dirty
        # https://github.com/0day-ci/linux/commit/ce304ecb5f2709fa58ef6f16cf8e89ddbd7e42cd
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Amey-Narkhede/PCI-Expose-and-manage-PCI-device-reset/20210801-222806
        git checkout ce304ecb5f2709fa58ef6f16cf8e89ddbd7e42cd
        # save the attached .config to linux build tree
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/pci/

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


sparse warnings: (new ones prefixed by >>)
   drivers/pci/pci.c:1052:13: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1052:21: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1052:31: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1052:39: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1061:35: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1061:54: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1062:19: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1062:37: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1092:23: sparse: sparse: invalid assignment: |=
   drivers/pci/pci.c:1092:23: sparse:    left side has type unsigned short
   drivers/pci/pci.c:1092:23: sparse:    right side has type restricted pci_power_t
   drivers/pci/pci.c:1097:57: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1119:28: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted pci_power_t [usertype] current_state @@     got int @@
   drivers/pci/pci.c:1119:28: sparse:     expected restricted pci_power_t [usertype] current_state
   drivers/pci/pci.c:1119:28: sparse:     got int
   drivers/pci/pci.c:1168:36: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted pci_power_t [usertype] current_state @@     got int @@
   drivers/pci/pci.c:1168:36: sparse:     expected restricted pci_power_t [usertype] current_state
   drivers/pci/pci.c:1168:36: sparse:     got int
   drivers/pci/pci.c:1340:13: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1340:21: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1342:18: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1342:26: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1365:13: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1365:22: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1372:46: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1372:54: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:1730:38: sparse: sparse: array of flexible structures
   drivers/pci/pci.c:1917:36: sparse: sparse: incorrect type in assignment (different base types) @@     expected restricted pci_power_t [usertype] current_state @@     got int @@
   drivers/pci/pci.c:1917:36: sparse:     expected restricted pci_power_t [usertype] current_state
   drivers/pci/pci.c:1917:36: sparse:     got int
   drivers/pci/pci.c:2313:44: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:2614:61: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:2615:45: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:2804:20: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:2804:38: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:2827:49: sparse: sparse: restricted pci_power_t degrades to integer
   drivers/pci/pci.c:2827:67: sparse: sparse: restricted pci_power_t degrades to integer
>> drivers/pci/pci.c:4636:6: sparse: sparse: symbol 'pcie_has_flr' was not declared. Should it be static?
   drivers/pci/pci.c:4768:13: sparse: sparse: invalid assignment: |=
   drivers/pci/pci.c:4768:13: sparse:    left side has type unsigned short
   drivers/pci/pci.c:4768:13: sparse:    right side has type restricted pci_power_t
   drivers/pci/pci.c:4773:13: sparse: sparse: invalid assignment: |=
   drivers/pci/pci.c:4773:13: sparse:    left side has type unsigned short
   drivers/pci/pci.c:4773:13: sparse:    right side has type restricted pci_power_t

Please review and possibly fold the followup patch.

---
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: 38524 bytes --]

[RFC PATCH] PCI: pcie_has_flr() can be static

[kernel test robot]

drivers/pci/pci.c:4636:6: warning: symbol 'pcie_has_flr' was not declared. Should it be static?

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
---
 pci.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 338c98bb60968..dba075bd11114 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4633,7 +4633,7 @@ EXPORT_SYMBOL(pci_wait_for_pending_transaction);
  * Returns true if the device advertises support for PCIe function level
  * resets.
  */
-bool pcie_has_flr(struct pci_dev *dev)
+static bool pcie_has_flr(struct pci_dev *dev)
 {
 	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
 		return false;

Re: [PATCH v13 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods

[kernel test robot]

[-- Attachment #1: Type: text/plain, Size: 3268 bytes --]

Hi Amey,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on pci/next]
[also build test WARNING on pm/linux-next cryptodev/master crypto/master linus/master v5.14-rc3 next-20210730]
[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/PCI-Expose-and-manage-PCI-device-reset/20210801-222806
base:   https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next
config: x86_64-randconfig-r025-20210801 (attached as .config)
compiler: clang version 13.0.0 (https://github.com/llvm/llvm-project 4f71f59bf3d9914188a11d0c41bedbb339d36ff5)
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/ce304ecb5f2709fa58ef6f16cf8e89ddbd7e42cd
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Amey-Narkhede/PCI-Expose-and-manage-PCI-device-reset/20210801-222806
        git checkout ce304ecb5f2709fa58ef6f16cf8e89ddbd7e42cd
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 

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

All warnings (new ones prefixed by >>):

>> drivers/pci/pci.c:4636:6: warning: no previous prototype for function 'pcie_has_flr' [-Wmissing-prototypes]
   bool pcie_has_flr(struct pci_dev *dev)
        ^
   drivers/pci/pci.c:4636:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   bool pcie_has_flr(struct pci_dev *dev)
   ^
   static 
   1 warning generated.


vim +/pcie_has_flr +4636 drivers/pci/pci.c

3775a209d38aa3 Casey Leedom      2013-08-06  4628  
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4629  /**
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4630   * pcie_has_flr - check if a device supports function level resets
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4631   * @dev: device to check
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4632   *
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4633   * Returns true if the device advertises support for PCIe function level
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4634   * resets.
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4635   */
2d2917f7747805 Alex Williamson   2018-08-09 @4636  bool pcie_has_flr(struct pci_dev *dev)
3775a209d38aa3 Casey Leedom      2013-08-06  4637  {
f65fd1aa4f9881 Sasha Neftin      2017-04-03  4638  	if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4639  		return false;
3775a209d38aa3 Casey Leedom      2013-08-06  4640  
e8213ae6f11e62 Amey Narkhede     2021-08-01  4641  	return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
a60a2b73ba69ab Christoph Hellwig 2017-04-14  4642  }
3775a209d38aa3 Casey Leedom      2013-08-06  4643  

---
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: 35557 bytes --]

Re: [PATCH v13 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods

[Bjorn Helgaas]

On Sun, Aug 01, 2021 at 07:55:11PM +0530, Amey Narkhede wrote:
> Currently there is separate function pcie_has_flr() to probe if PCIe FLR
> is supported by the device which does not match the calling convention
> followed by reset methods which use second function argument to decide
> whether to probe or not. Add new function pcie_reset_flr() that follows
> the calling convention of reset methods.
> 
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> ---
>  drivers/crypto/cavium/nitrox/nitrox_main.c |  4 +--
>  drivers/pci/pci.c                          | 40 +++++++++++++++-------
>  drivers/pci/pcie/aer.c                     | 12 +++----
>  drivers/pci/quirks.c                       |  9 ++---
>  include/linux/pci.h                        |  2 +-
>  5 files changed, 38 insertions(+), 29 deletions(-)

>  int pcie_flr(struct pci_dev *dev)
>  {
> @@ -4655,7 +4653,26 @@ int pcie_flr(struct pci_dev *dev)
>  
>  	return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
>  }
> -EXPORT_SYMBOL_GPL(pcie_flr);
> +EXPORT_SYMBOL(pcie_flr);

Why this change?  If it's unintentional and there's no other reason to
repost, I can fix it up locally.

Re: [PATCH v13 5/9] PCI: Allow userspace to query and set device reset mechanism

[Bjorn Helgaas]

On Sun, Aug 01, 2021 at 07:55:14PM +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                 |   1 +
>  drivers/pci/pci.c                       | 105 ++++++++++++++++++++++++
>  drivers/pci/pci.h                       |   2 +
>  4 files changed, 127 insertions(+)
> 
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ef00fada2efb..ef66b62bf025 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -121,6 +121,25 @@ Description:
>  		child buses, and re-discover devices removed earlier
>  		from this part of the device tree.
>  
> +What:		/sys/bus/pci/devices/.../reset_method
> +Date:		March 2021
> +Contact:	Amey Narkhede <ameynarkhede03@gmail.com>
> +Description:
> +		Some devices allow an individual function to be reset
> +		without affecting other functions in the same slot.
> +
> +		For devices that have this support, a file named
> +		reset_method will be present in sysfs. Initially reading
> +		this file will give names of the device supported reset
> +		methods and their ordering. After write, this file will
> +		give names and ordering of currently enabled reset methods.
> +		Writing the name or space separated list of names of any of
> +		the device supported reset methods to this file will set
> +		the reset methods and their ordering to be used when
> +		resetting the device. Writing empty string to this file
> +		will disable ability to reset the device and writing
> +		"default" will return to the original value.
> +
>  What:		/sys/bus/pci/devices/.../reset
>  Date:		July 2009
>  Contact:	Michael S. Tsirkin <mst@redhat.com>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 316f70c3e3b4..54ee7193b463 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1491,6 +1491,7 @@ const struct attribute_group *pci_dev_groups[] = {
>  	&pci_dev_config_attr_group,
>  	&pci_dev_rom_attr_group,
>  	&pci_dev_reset_attr_group,
> +	&pci_dev_reset_method_attr_group,
>  	&pci_dev_vpd_attr_group,
>  #ifdef CONFIG_DMI
>  	&pci_dev_smbios_attr_group,
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 932dd21e759b..c496cd164aca 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5132,6 +5132,111 @@ static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
>  	{ pci_reset_bus_function, .name = "bus" },
>  };
>  
> +static ssize_t reset_method_show(struct device *dev,
> +				 struct device_attribute *attr,
> +				 char *buf)

Looks like "buf" would fit on the previous line.

> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	ssize_t len = 0;
> +	int i, m;
> +
> +	for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> +		m = pdev->reset_methods[i];
> +		if (!m)
> +			break;
> +
> +		len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
> +				     pci_reset_fn_methods[m].name);
> +	}
> +
> +	if (len)
> +		len += sysfs_emit_at(buf, len, "\n");
> +
> +	return len;
> +}
> +
> +static ssize_t reset_method_store(struct device *dev,
> +				  struct device_attribute *attr,
> +				  const char *buf, size_t count)
> +{
> +	struct pci_dev *pdev = to_pci_dev(dev);
> +	int i = 0;
> +	char *name, *options = NULL;
> +
> +	if (count >= (PAGE_SIZE - 1))
> +		return -EINVAL;
> +
> +	if (sysfs_streq(buf, "")) {
> +		pdev->reset_methods[0] = 0;
> +		pci_warn(pdev, "All device reset methods disabled by user");
> +		return count;
> +	}

I think it's possible for the user to disable all reset methods by
supplying only junk.  Maybe this check could be moved to the end of
the function to catch both the "empty input" and the "input contains
only junk" cases?

> +	if (sysfs_streq(buf, "default")) {
> +		pci_init_reset_methods(pdev);
> +		return count;
> +	}
> +
> +	options = kstrndup(buf, count, GFP_KERNEL);
> +	if (!options)
> +		return -ENOMEM;
> +

  i = 0;

here so it's nearer the loop it controls.

> +	while ((name = strsep(&options, " ")) != NULL) {
> +		int m;
> +
> +		if (sysfs_streq(name, ""))
> +			continue;
> +
> +		name = strim(name);
> +
> +		for (m = 1; m < PCI_NUM_RESET_METHODS && i < PCI_NUM_RESET_METHODS; m++) {
> +			if (sysfs_streq(name, pci_reset_fn_methods[m].name) &&
> +			    !pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
> +				pdev->reset_methods[i++] = m;
> +				break;
> +			}
> +		}
> +
> +		if (m == PCI_NUM_RESET_METHODS) {
> +			kfree(options);
> +			return -EINVAL;

In this case, I think we have actually updated pdev->reset_methods[],
but we still return -EINVAL, right?  If we decide to silently ignore
unrecognized methods, we probably should return success here.

> +
> +		}
> +	}
> +
> +	if (i < PCI_NUM_RESET_METHODS)
> +		pdev->reset_methods[i] = 0;
> +
> +	if (!pci_reset_fn_methods[1].reset_fn(pdev, 1) && pdev->reset_methods[0] != 1)

Looks longer than 80 columns?  "Fixed" by rewrapping in patch 9/9, but
would be better to fix here.

> +		pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
> +
> +	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;
> +}
> +
> +const struct attribute_group pci_dev_reset_method_attr_group = {
> +	.attrs = pci_dev_reset_method_attrs,
> +	.is_visible = pci_dev_reset_method_attr_is_visible,
> +};
> +
>  /**
>   * __pci_reset_function_locked - reset a PCI device function while holding
>   * the @dev mutex lock.
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index 7438953745e0..31458d48eda7 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -714,4 +714,6 @@ static inline int pci_acpi_program_hp_params(struct pci_dev *dev)
>  extern const struct attribute_group aspm_ctrl_attr_group;
>  #endif
>  
> +extern const struct attribute_group pci_dev_reset_method_attr_group;
> +
>  #endif /* DRIVERS_PCI_H */
> -- 
> 2.32.0
> 

Re: [PATCH v13 9/9] PCI: Change the type of probe argument in reset functions

[Bjorn Helgaas]

On Sun, Aug 01, 2021 at 07:55:18PM +0530, Amey Narkhede wrote:
> Change the type of probe argument in functions which implement reset
> methods from int to bool to make the context and intent clear.
> 
> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
> Suggested-by: Krzysztof Wilczyński <kw@linux.com>
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> ---
>  drivers/crypto/cavium/nitrox/nitrox_main.c    |  2 +-
>  .../ethernet/cavium/liquidio/lio_vf_main.c    |  2 +-
>  drivers/pci/hotplug/pciehp.h                  |  2 +-
>  drivers/pci/hotplug/pciehp_hpc.c              |  4 +-
>  drivers/pci/hotplug/pnv_php.c                 |  4 +-
>  drivers/pci/pci-acpi.c                        |  7 +-
>  drivers/pci/pci.c                             | 69 ++++++++++---------
>  drivers/pci/pci.h                             | 12 ++--
>  drivers/pci/pcie/aer.c                        |  2 +-
>  drivers/pci/quirks.c                          | 34 ++++-----
>  include/linux/pci.h                           |  5 +-
>  include/linux/pci_hotplug.h                   |  2 +-
>  12 files changed, 75 insertions(+), 70 deletions(-)
> 
> diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
> index 15d6c8452807..f97fa8e997b5 100644
> --- a/drivers/crypto/cavium/nitrox/nitrox_main.c
> +++ b/drivers/crypto/cavium/nitrox/nitrox_main.c
> @@ -306,7 +306,7 @@ static int nitrox_device_flr(struct pci_dev *pdev)
>  		return -ENOMEM;
>  	}
>  
> -	pcie_reset_flr(pdev, 0);
> +	pcie_reset_flr(pdev, PCI_RESET_DO_RESET);
>  
>  	pci_restore_state(pdev);
>  
> diff --git a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> index 336d149ee2e2..6e666be6907a 100644
> --- a/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> +++ b/drivers/net/ethernet/cavium/liquidio/lio_vf_main.c
> @@ -526,7 +526,7 @@ static void octeon_destroy_resources(struct octeon_device *oct)
>  			oct->irq_name_storage = NULL;
>  		}
>  		/* Soft reset the octeon device before exiting */
> -		if (!pcie_reset_flr(oct->pci_dev, 1))
> +		if (!pcie_reset_flr(oct->pci_dev, PCI_RESET_PROBE))
>  			octeon_pci_flr(oct);
>  		else
>  			cn23xx_vf_ask_pf_to_do_flr(oct);
> diff --git a/drivers/pci/hotplug/pciehp.h b/drivers/pci/hotplug/pciehp.h
> index 4fd200d8b0a9..f12e1ef9f183 100644
> --- a/drivers/pci/hotplug/pciehp.h
> +++ b/drivers/pci/hotplug/pciehp.h
> @@ -181,7 +181,7 @@ void pciehp_release_ctrl(struct controller *ctrl);
>  
>  int pciehp_sysfs_enable_slot(struct hotplug_slot *hotplug_slot);
>  int pciehp_sysfs_disable_slot(struct hotplug_slot *hotplug_slot);
> -int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, int probe);
> +int pciehp_reset_slot(struct hotplug_slot *hotplug_slot, bool mode);

Changing this to bool is ok, but I think changing the name from
"probe" to "mode" makes it worse.  It makes sense that "probe == true"
means do a probe instead of a reset, but "mode == true" tells me
nothing.

Bjorn

Re: [PATCH v13 2/9] PCI: Add pcie_reset_flr to follow calling convention of other reset methods

[Amey Narkhede]

On 21/08/02 05:44PM, Bjorn Helgaas wrote:
> On Sun, Aug 01, 2021 at 07:55:11PM +0530, Amey Narkhede wrote:
> > Currently there is separate function pcie_has_flr() to probe if PCIe FLR
> > is supported by the device which does not match the calling convention
> > followed by reset methods which use second function argument to decide
> > whether to probe or not. Add new function pcie_reset_flr() that follows
> > the calling convention of reset methods.
> >
> > Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> > ---
> >  drivers/crypto/cavium/nitrox/nitrox_main.c |  4 +--
> >  drivers/pci/pci.c                          | 40 +++++++++++++++-------
> >  drivers/pci/pcie/aer.c                     | 12 +++----
> >  drivers/pci/quirks.c                       |  9 ++---
> >  include/linux/pci.h                        |  2 +-
> >  5 files changed, 38 insertions(+), 29 deletions(-)
>
> >  int pcie_flr(struct pci_dev *dev)
> >  {
> > @@ -4655,7 +4653,26 @@ int pcie_flr(struct pci_dev *dev)
> >
> >  	return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS);
> >  }
> > -EXPORT_SYMBOL_GPL(pcie_flr);
> > +EXPORT_SYMBOL(pcie_flr);
>
> Why this change?  If it's unintentional and there's no other reason to
> repost, I can fix it up locally.
Yeah my bad it was unintentional.

Re: [PATCH v13 5/9] PCI: Allow userspace to query and set device reset mechanism

[Amey Narkhede]

On 21/08/02 05:55PM, Bjorn Helgaas wrote:
> On Sun, Aug 01, 2021 at 07:55:14PM +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>
> > ---
> > +
[...]
> > +static ssize_t reset_method_store(struct device *dev,
> > +				  struct device_attribute *attr,
> > +				  const char *buf, size_t count)
> > +{
> > +	struct pci_dev *pdev = to_pci_dev(dev);
> > +	int i = 0;
> > +	char *name, *options = NULL;
> > +
> > +	if (count >= (PAGE_SIZE - 1))
> > +		return -EINVAL;
> > +
> > +	if (sysfs_streq(buf, "")) {
> > +		pdev->reset_methods[0] = 0;
> > +		pci_warn(pdev, "All device reset methods disabled by user");
> > +		return count;
> > +	}
>
> I think it's possible for the user to disable all reset methods by
> supplying only junk.  Maybe this check could be moved to the end of
> the function to catch both the "empty input" and the "input contains
> only junk" cases?
>
Supplying only junk doesn't disable the reset. It returns -EINVAL as it
will go in following while loop. The check m == PCI_NUM_RESET_METHODS
returns -EINVAL

> > +	if (sysfs_streq(buf, "default")) {
> > +		pci_init_reset_methods(pdev);
> > +		return count;
> > +	}
> > +
> > +	options = kstrndup(buf, count, GFP_KERNEL);
> > +	if (!options)
> > +		return -ENOMEM;
> > +
>
>   i = 0;
>
> here so it's nearer the loop it controls.
>
> > +	while ((name = strsep(&options, " ")) != NULL) {
> > +		int m;
> > +
> > +		if (sysfs_streq(name, ""))
> > +			continue;
> > +
> > +		name = strim(name);
> > +
> > +		for (m = 1; m < PCI_NUM_RESET_METHODS && i < PCI_NUM_RESET_METHODS; m++) {
> > +			if (sysfs_streq(name, pci_reset_fn_methods[m].name) &&
> > +			    !pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
> > +				pdev->reset_methods[i++] = m;
> > +				break;
> > +			}
> > +		}
> > +
> > +		if (m == PCI_NUM_RESET_METHODS) {
> > +			kfree(options);
> > +			return -EINVAL;
>
> In this case, I think we have actually updated pdev->reset_methods[],
> but we still return -EINVAL, right?  If we decide to silently ignore
> unrecognized methods, we probably should return success here.
>
Is it okay to do that? I hope it won't cause any trouble for user
scripts

Thanks,
Amey

[...]

Re: [PATCH v13 5/9] PCI: Allow userspace to query and set device reset mechanism

[Shanker R Donthineni]

On 8/1/21 9:25 AM, Amey Narkhede wrote:
> External email: Use caution opening links or attachments
>
>
> Add reset_method sysfs attribute to enable user to query and set user
> preferred device reset methods and their ordering.
>
> Co-developed-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
> ---
>  Documentation/ABI/testing/sysfs-bus-pci |  19 +++++
>  drivers/pci/pci-sysfs.c                 |   1 +
>  drivers/pci/pci.c                       | 105 ++++++++++++++++++++++++
>  drivers/pci/pci.h                       |   2 +
>  4 files changed, 127 insertions(+)
>
> diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci
> index ef00fada2efb..ef66b62bf025 100644
> --- a/Documentation/ABI/testing/sysfs-bus-pci
> +++ b/Documentation/ABI/testing/sysfs-bus-pci
> @@ -121,6 +121,25 @@ Description:
>                 child buses, and re-discover devices removed earlier
>                 from this part of the device tree.
>
> +What:          /sys/bus/pci/devices/.../reset_method
> +Date:          March 2021
> +Contact:       Amey Narkhede <ameynarkhede03@gmail.com>
> +Description:
> +               Some devices allow an individual function to be reset
> +               without affecting other functions in the same slot.
> +
> +               For devices that have this support, a file named
> +               reset_method will be present in sysfs. Initially reading
> +               this file will give names of the device supported reset
> +               methods and their ordering. After write, this file will
> +               give names and ordering of currently enabled reset methods.
> +               Writing the name or space separated list of names of any of
> +               the device supported reset methods to this file will set
> +               the reset methods and their ordering to be used when
> +               resetting the device. Writing empty string to this file
> +               will disable ability to reset the device and writing
> +               "default" will return to the original value.
> +
>  What:          /sys/bus/pci/devices/.../reset
>  Date:          July 2009
>  Contact:       Michael S. Tsirkin <mst@redhat.com>
> diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
> index 316f70c3e3b4..54ee7193b463 100644
> --- a/drivers/pci/pci-sysfs.c
> +++ b/drivers/pci/pci-sysfs.c
> @@ -1491,6 +1491,7 @@ const struct attribute_group *pci_dev_groups[] = {
>         &pci_dev_config_attr_group,
>         &pci_dev_rom_attr_group,
>         &pci_dev_reset_attr_group,
> +       &pci_dev_reset_method_attr_group,
>         &pci_dev_vpd_attr_group,
>  #ifdef CONFIG_DMI
>         &pci_dev_smbios_attr_group,
> diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
> index 932dd21e759b..c496cd164aca 100644
> --- a/drivers/pci/pci.c
> +++ b/drivers/pci/pci.c
> @@ -5132,6 +5132,111 @@ static const struct pci_reset_fn_method pci_reset_fn_methods[] = {
>         { pci_reset_bus_function, .name = "bus" },
>  };
>
> +static ssize_t reset_method_show(struct device *dev,
> +                                struct device_attribute *attr,
> +                                char *buf)
> +{
> +       struct pci_dev *pdev = to_pci_dev(dev);
> +       ssize_t len = 0;
> +       int i, m;
> +
> +       for (i = 0; i < PCI_NUM_RESET_METHODS; i++) {
> +               m = pdev->reset_methods[i];
> +               if (!m)
> +                       break;
> +
> +               len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "",
> +                                    pci_reset_fn_methods[m].name);
> +       }
> +
> +       if (len)
> +               len += sysfs_emit_at(buf, len, "\n");
> +
> +       return len;
> +}
> +
> +static ssize_t reset_method_store(struct device *dev,
> +                                 struct device_attribute *attr,
> +                                 const char *buf, size_t count)
> +{
> +       struct pci_dev *pdev = to_pci_dev(dev);
> +       int i = 0;
> +       char *name, *options = NULL;
> +
> +       if (count >= (PAGE_SIZE - 1))
> +               return -EINVAL;
> +
> +       if (sysfs_streq(buf, "")) {
> +               pdev->reset_methods[0] = 0;
> +               pci_warn(pdev, "All device reset methods disabled by user");
> +               return count;
> +       }
> +
> +       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 m;
> +
> +               if (sysfs_streq(name, ""))
> +                       continue;
> +
> +               name = strim(name);
> +
> +               for (m = 1; m < PCI_NUM_RESET_METHODS && i < PCI_NUM_RESET_METHODS; m++) {
> +                       if (sysfs_streq(name, pci_reset_fn_methods[m].name) &&
> +                           !pci_reset_fn_methods[m].reset_fn(pdev, 1)) {
> +                               pdev->reset_methods[i++] = m;
> +                               break;
> +                       }
> +               }
> +
Checking reset method logic isn't optimized, iterating through all entries if the
device doesn't support a requested method.

Something like this:
        for (m = 1; m < PCI_NUM_RESET_METHODS && i < PCI_NUM_RESET_METHODS; m++) {
                if (!sysfs_streq(name, pci_reset_fn_methods[m].name))
                        continue;
                if(!pci_reset_fn_methods[m].reset_fn(pdev, 1))
                        pdev->reset_methods[i++] = m;
                break;
        }

I think we should avoid duplicate entries in pdev->reset_methods.
Example:
   root# cat reset_method
   acpi flr bus

   root# echo "acpi flr bus flr" > reset_method
   root# cat reset_method
   acpi flr bus flr




> +               if (m == PCI_NUM_RESET_METHODS) {
> +                       kfree(options);
> +                       return -EINVAL;
Set the last entry to zero in pdev->reset_methods otherwise the inconsistent
methods are enabled.
Example:
   root# cat reset_method
   acpi flr bus

   root# echo "flr a" > reset_method
   root# cat reset_method
   flr flr bus

> +
> +               }
> +       }
> +
> +       if (i < PCI_NUM_RESET_METHODS)
> +               pdev->reset_methods[i] = 0;
> +
Last entry can be set unconditionally after removing the duplicate entries.
Refactored code to filter duplicate entries and warn the user about the invalid
& unsupported reset methods.

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);
        char *name, *options = NULL;
        int i, m, n = 0;

        if (count >= (PAGE_SIZE - 1))
                return -EINVAL;

        if (sysfs_streq(buf, ""))
                goto done;

        if (sysfs_streq(buf, "default")) {
                pci_init_reset_methods(pdev);
                return count;
        }

        options = kstrndup(buf, count, GFP_KERNEL);
        if (!options)
                return -ENOMEM;

        while ((name = strsep(&options, " ")) != NULL) {
                if (sysfs_streq(name, ""))
                        continue;
                name = strim(name);

                /* Validate reset method */
                for (m = 1; m < PCI_NUM_RESET_METHODS; m++) {
                        if (sysfs_streq(name, pci_reset_fn_methods[m].name))
                                break;
                }
                if (m == PCI_NUM_RESET_METHODS) {
                        pci_warn(pdev, "Skip invalid reset method '%s'", name);
                        continue;
                }

                /* Check if the reset method is already enabled */
                for (i = 0; i < n; i++) {
                        if (pdev->reset_methods[i] == m)
                                break;
                }
                if (i < n)
                        continue;

                /* Probe the requested reset method */
                if (pci_reset_fn_methods[m].reset_fn(pdev, 1))
                        pci_warn(pdev, "Unsupported reset method '%s'", name);

                pdev->reset_methods[n++] = m;
                BUG_ON(n == PCI_NUM_RESET_METHODS)
       }
        kfree(options);

done:
        pdev->reset_methods[n] = 0;
        if (pdev->reset_methods[0] == 0) {
                pci_warn(pdev, "All device reset methods are disabled");
        } else if ((pdev->reset_methods[0] != 1) &&
                   !pci_reset_fn_methods[1].reset_fn(pdev, 1)) {
                pci_warn(pdev, "Device specific reset disabled/de-prioritized by user");
        }
        return count;
}