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>

6 files changed, 14 insertions, 81 deletions

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 6394e7746fb5..3e5efb83e9a2 100644
--- 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 4a818b07a1af..c0540c3761dc 100644
--- 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 6b116d7fdb89..1ae5d94944eb 100644
--- 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 1ac57e9e1e71..9d5b71a7f837 100644
--- 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 1e673619b101..64b5e081cdb2 100644
--- 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 5075cb9e850c..50a9522ab07d 100644
--- a/drivers/pci/pcie/portdrv_core.c
+++ b/drivers/pci/pcie/portdrv_core.c
@@ -459,27 +459,6 @@ static int find_service_iter(struct device *device, void *data)
 }
 
 /**
- * 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
  * @service: For the service to find