PCI: Add pcie_reset_flr() with 'probe' argument

Most reset methods are of the form "pci_*_reset(dev, probe)".  pcie_flr()
was an exception because it relied on a separate pcie_has_flr() function
instead of taking a "probe" argument.

Add "pcie_reset_flr(dev, probe)" to follow the convention.  Remove
pcie_has_flr().

Some pcie_flr() callers that did not use pcie_has_flr() remain.

[bhelgaas: commit log, rework pcie_reset_flr() to use dev->devcap directly]
Link: https://lore.kernel.org/r/20210817180500.1253-3-ameynarkhede03@gmail.com
Signed-off-by: Amey Narkhede <ameynarkhede03@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Raphael Norwitz <raphael.norwitz@nutanix.com>

diff --git a/drivers/crypto/cavium/nitrox/nitrox_main.c b/drivers/crypto/cavium/nitrox/nitrox_main.c
index 96bc7b5..2db3fd5 100644 (file)
--- 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 b7a9f68..b0a63bd 100644 (file)
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -4622,29 +4622,12 @@ int pci_wait_for_pending_transaction(struct pci_dev *dev)
 }
 EXPORT_SYMBOL(pci_wait_for_pending_transaction);
 
-/**
- * pcie_has_flr - check if a device supports function level resets
- * @dev: device to check
- *
- * Returns true if the device advertises support for PCIe function level
- * resets.
- */
-bool pcie_has_flr(struct pci_dev *dev)
-{
-       if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
-               return false;
-
-       return FIELD_GET(PCI_EXP_DEVCAP_FLR, dev->devcap) == 1;
-}
-EXPORT_SYMBOL_GPL(pcie_has_flr);
-
 /**
  * pcie_flr - initiate a PCIe function level reset
  * @dev: device to reset
  *
- * Initiate a function level reset on @dev.  The caller should ensure the
- * device supports FLR before calling this function, e.g. by using the
- * pcie_has_flr() helper.
+ * Initiate a function level reset unconditionally on @dev without
+ * checking any flags and DEVCAP
  */
 int pcie_flr(struct pci_dev *dev)
 {
@@ -4667,6 +4650,28 @@ int pcie_flr(struct pci_dev *dev)
 }
 EXPORT_SYMBOL_GPL(pcie_flr);
 
+/**
+ * pcie_reset_flr - initiate a PCIe function level reset
+ * @dev: device to reset
+ * @probe: If set, only check if the device can be reset this way.
+ *
+ * Initiate a function level reset on @dev.
+ */
+int pcie_reset_flr(struct pci_dev *dev, int probe)
+{
+       if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET)
+               return -ENOTTY;
+
+       if (!(dev->devcap & PCI_EXP_DEVCAP_FLR))
+               return -ENOTTY;
+
+       if (probe)
+               return 0;
+
+       return pcie_flr(dev);
+}
+EXPORT_SYMBOL_GPL(pcie_reset_flr);
+
 static int pci_af_flr(struct pci_dev *dev, int probe)
 {
        int pos;
@@ -5149,11 +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;
@@ -5184,8 +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 df4ba9b..031379d 100644 (file)
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -1407,13 +1407,11 @@ 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 6d74386..a8a167b 100644 (file)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3852,7 +3852,7 @@ 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)
@@ -3921,13 +3921,10 @@ 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 1179c0e..1de37e3 100644 (file)
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1229,7 +1229,7 @@ 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);