PCI/ERR: Remove service dependency in pcie_do_recovery()

Previously we passed the PCIe service type parameter to pcie_do_recovery(),
where reset_link() looked up the underlying pci_port_service_driver and its
.reset_link() function pointer. Instead of using this roundabout way, we
can just pass the driver-specific .reset_link() callback function when
calling pcie_do_recovery() function.

This allows us to call pcie_do_recovery() from code that is not a PCIe port
service driver, e.g., Error Disconnect Recover (EDR) support.

Remove pcie_port_find_service() and pcie_port_service_driver.reset_link
since they are now unused.

Link: https://lore.kernel.org/r/60e02b87b526cdf2930400059d98704bf0a147d1.1585000084.git.sathyanarayanan.kuppuswamy@linux.intel.com
Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

diff --git a/Documentation/PCI/pcieaer-howto.rst b/Documentation/PCI/pcieaer-howto.rst
index 18bdefaafd1a89a42ed70a1740ca44b4bfd86a4f..afbd8c1c321dd492fbda906542992b0b1aaf6ffe 100644 (file)
--- a/Documentation/PCI/pcieaer-howto.rst
+++ b/Documentation/PCI/pcieaer-howto.rst
@@ -156,12 +156,6 @@ default reset_link function, but different upstream ports might
 have different specifications to reset pci express link, so all
 upstream ports should provide their own reset_link functions.
 
-In struct pcie_port_service_driver, a new pointer, reset_link, is
-added.
-::
-
-       pci_ers_result_t (*reset_link) (struct pci_dev *dev);
-
 Section 3.2.2.2 provides more detailed info on when to call
 reset_link.
 
@@ -212,15 +206,10 @@ error_detected(dev, pci_channel_io_frozen) to all drivers within
 a hierarchy in question. Then, performing link reset at upstream is
 necessary. As different kinds of devices might use different approaches
 to reset link, AER port service driver is required to provide the
-function to reset link. Firstly, kernel looks for if the upstream
-component has an aer driver. If it has, kernel uses the reset_link
-callback of the aer driver. If the upstream component has no aer driver
-and the port is downstream port, we will perform a hot reset as the
-default by setting the Secondary Bus Reset bit of the Bridge Control
-register associated with the downstream port. As for upstream ports,
-they should provide their own aer service drivers with reset_link
-function. If error_detected returns PCI_ERS_RESULT_CAN_RECOVER and
-reset_link returns PCI_ERS_RESULT_RECOVERED, the error handling goes
+function to reset link via callback parameter of pcie_do_recovery()
+function. If reset_link is not NULL, recovery function will use it
+to reset the link. If error_detected returns PCI_ERS_RESULT_CAN_RECOVER
+and reset_link returns PCI_ERS_RESULT_RECOVERED, the error handling goes
 to mmio_enabled.
 
 helper functions

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6394e7746fb54217e6caa37abb690449686dad30..3e5efb83e9a22271cb03a095cf8c127d14db054b 100644 (file)
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -548,7 +548,7 @@ static inline int pci_dev_specific_disable_acs_redir(struct pci_dev *dev)
 
 /* PCI error reporting and recovery */
 void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
-                     u32 service);
+                     pci_ers_result_t (*reset_link)(struct pci_dev *pdev));
 
 bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
 #ifdef CONFIG_PCIEASPM

diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 4a818b07a1afb72ba197094a939f26ebed991873..c0540c3761dc040a20293a2f2b80805d861477b9 100644 (file)
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -102,6 +102,7 @@ struct aer_stats {
 #define ERR_UNCOR_ID(d)                        (d >> 16)
 
 static int pcie_aer_disable;
+static pci_ers_result_t aer_root_reset(struct pci_dev *dev);
 
 void pci_no_aer(void)
 {
@@ -1053,11 +1054,9 @@ static void handle_error_source(struct pci_dev *dev, struct aer_err_info *info)
                                        info->status);
                pci_aer_clear_device_status(dev);
        } else if (info->severity == AER_NONFATAL)
-               pcie_do_recovery(dev, pci_channel_io_normal,
-                                PCIE_PORT_SERVICE_AER);
+               pcie_do_recovery(dev, pci_channel_io_normal, aer_root_reset);
        else if (info->severity == AER_FATAL)
-               pcie_do_recovery(dev, pci_channel_io_frozen,
-                                PCIE_PORT_SERVICE_AER);
+               pcie_do_recovery(dev, pci_channel_io_frozen, aer_root_reset);
        pci_dev_put(dev);
 }
 
@@ -1094,10 +1093,10 @@ static void aer_recover_work_func(struct work_struct *work)
                cper_print_aer(pdev, entry.severity, entry.regs);
                if (entry.severity == AER_NONFATAL)
                        pcie_do_recovery(pdev, pci_channel_io_normal,
-                                        PCIE_PORT_SERVICE_AER);
+                                        aer_root_reset);
                else if (entry.severity == AER_FATAL)
                        pcie_do_recovery(pdev, pci_channel_io_frozen,
-                                        PCIE_PORT_SERVICE_AER);
+                                        aer_root_reset);
                pci_dev_put(pdev);
        }
 }
@@ -1501,7 +1500,6 @@ static struct pcie_port_service_driver aerdriver = {
 
        .probe          = aer_probe,
        .remove         = aer_remove,
-       .reset_link     = aer_root_reset,
 };
 
 /**

diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 6b116d7fdb8985917e9e10ec92100eab0806f1d0..1ae5d94944eb9b1d6618d2842f5e691f3ffc63d9 100644 (file)
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -227,7 +227,7 @@ static irqreturn_t dpc_handler(int irq, void *context)
        }
 
        /* We configure DPC so it only triggers on ERR_FATAL */
-       pcie_do_recovery(pdev, pci_channel_io_frozen, PCIE_PORT_SERVICE_DPC);
+       pcie_do_recovery(pdev, pci_channel_io_frozen, dpc_reset_link);
 
        return IRQ_HANDLED;
 }
@@ -313,7 +313,6 @@ static struct pcie_port_service_driver dpcdriver = {
        .service        = PCIE_PORT_SERVICE_DPC,
        .probe          = dpc_probe,
        .remove         = dpc_remove,
-       .reset_link     = dpc_reset_link,
 };
 
 int __init pcie_dpc_init(void)

diff --git a/drivers/pci/pcie/err.c b/drivers/pci/pcie/err.c
index 1ac57e9e1e714424b4f406784b051cffe0202c9f..9d5b71a7f8371efa7ba860e86308f674fa1b2caa 100644 (file)
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -146,49 +146,9 @@ out:
        return 0;
 }
 
-/**
- * default_reset_link - default reset function
- * @dev: pointer to pci_dev data structure
- *
- * Invoked when performing link reset on a Downstream Port or a
- * Root Port with no aer driver.
- */
-static pci_ers_result_t default_reset_link(struct pci_dev *dev)
-{
-       int rc;
-
-       rc = pci_bus_error_reset(dev);
-       pci_printk(KERN_DEBUG, dev, "downstream link has been reset\n");
-       return rc ? PCI_ERS_RESULT_DISCONNECT : PCI_ERS_RESULT_RECOVERED;
-}
-
-static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
-{
-       pci_ers_result_t status;
-       struct pcie_port_service_driver *driver = NULL;
-
-       driver = pcie_port_find_service(dev, service);
-       if (driver && driver->reset_link) {
-               status = driver->reset_link(dev);
-       } else if (pcie_downstream_port(dev)) {
-               status = default_reset_link(dev);
-       } else {
-               pci_printk(KERN_DEBUG, dev, "no link-reset support at upstream device %s\n",
-                       pci_name(dev));
-               return PCI_ERS_RESULT_DISCONNECT;
-       }
-
-       if (status != PCI_ERS_RESULT_RECOVERED) {
-               pci_printk(KERN_DEBUG, dev, "link reset at upstream device %s failed\n",
-                       pci_name(dev));
-               return PCI_ERS_RESULT_DISCONNECT;
-       }
-
-       return status;
-}
-
-void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
-                     u32 service)
+void pcie_do_recovery(struct pci_dev *dev,
+                     enum pci_channel_state state,
+                     pci_ers_result_t (*reset_link)(struct pci_dev *pdev))
 {
        pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
        struct pci_bus *bus;
@@ -205,9 +165,11 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
        pci_dbg(dev, "broadcast error_detected message\n");
        if (state == pci_channel_io_frozen) {
                pci_walk_bus(bus, report_frozen_detected, &status);
-               status = reset_link(dev, service);
-               if (status != PCI_ERS_RESULT_RECOVERED)
+               status = reset_link(dev);
+               if (status != PCI_ERS_RESULT_RECOVERED) {
+                       pci_warn(dev, "link reset failed\n");
                        goto failed;
+               }
        } else {
                pci_walk_bus(bus, report_normal_detected, &status);
        }

diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index 1e673619b101d0bb576aa501c6b2964462c09afe..64b5e081cdb29525dde1ec4b80b1179263bab31d 100644 (file)
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -92,9 +92,6 @@ struct pcie_port_service_driver {
        /* Device driver may resume normal operations */
        void (*error_resume)(struct pci_dev *dev);
 
-       /* Link Reset Capability - AER service driver specific */
-       pci_ers_result_t (*reset_link)(struct pci_dev *dev);
-
        int port_type;  /* Type of the port this driver can handle */
        u32 service;    /* Port service this device represents */
 
@@ -161,7 +158,5 @@ static inline int pcie_aer_get_firmware_first(struct pci_dev *pci_dev)
 }
 #endif
 
-struct pcie_port_service_driver *pcie_port_find_service(struct pci_dev *dev,
-                                                       u32 service);
 struct device *pcie_port_find_device(struct pci_dev *dev, u32 service);
 #endif /* _PORTDRV_H_ */

diff --git a/drivers/pci/pcie/portdrv_core.c b/drivers/pci/pcie/portdrv_core.c
index 5075cb9e850c56b6bbf9b2832af644aa484be652..50a9522ab07df98046490a1b79b09caf9d7ef581 100644 (file)
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -458,27 +458,6 @@ static int find_service_iter(struct device *device, void *data)
        return 0;
 }
 
-/**
- * pcie_port_find_service - find the service driver
- * @dev: PCI Express port the service is associated with
- * @service: Service to find
- *
- * Find PCI Express port service driver associated with given service
- */
-struct pcie_port_service_driver *pcie_port_find_service(struct pci_dev *dev,
-                                                       u32 service)
-{
-       struct pcie_port_service_driver *drv;
-       struct portdrv_service_data pdrvs;
-
-       pdrvs.drv = NULL;
-       pdrvs.service = service;
-       device_for_each_child(&dev->dev, &pdrvs, find_service_iter);
-
-       drv = pdrvs.drv;
-       return drv;
-}
-
 /**
  * pcie_port_find_device - find the struct device
  * @dev: PCI Express port the service is associated with