PCI/ERR: Simplify broadcast callouts

task #29600094

commit 542aeb9c8f930e4099432cb0bec17b92c0175e08 upstream.
Backport summary: for 4.19 kernel ICX PCIe Gen4 support.

There is no point in having a generic broadcast function if it needs to
have special cases for each callback it broadcasts.

Abstract the error broadcast to only the necessary information and removes
the now unnecessary helper to walk the bus.
Signed-off-by: NKeith Busch <keith.busch@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NSinan Kaya <okaya@kernel.org>
(cherry picked from commit 542aeb9c8f930e4099432cb0bec17b92c0175e08)
Signed-off-by: NEthan Zhao <haifeng.zhao@intel.com>
Signed-off-by: NArtie Ding <artie.ding@linux.alibaba.com>
Acked-by: NCaspar Zhang <caspar@linux.alibaba.com>

drivers/pci/pcie/err.c

@@ -19,11 +19,6 @@
 #include "portdrv.h"
 #include "../pci.h"
 
-struct aer_broadcast_data {
-	enum pci_channel_state state;
-	enum pci_ers_result result;
-};
-
 static pci_ers_result_t merge_result(enum pci_ers_result orig,
 				  enum pci_ers_result new)
 {
@@ -49,16 +44,15 @@ static pci_ers_result_t merge_result(enum pci_ers_result orig,
 	return orig;
 }
 
-static int report_error_detected(struct pci_dev *dev, void *data)
+static int report_error_detected(struct pci_dev *dev,
+				 enum pci_channel_state state,
+				 enum pci_ers_result *result)
 {
 	pci_ers_result_t vote;
 	const struct pci_error_handlers *err_handler;
-	struct aer_broadcast_data *result_data;
-
-	result_data = (struct aer_broadcast_data *) data;
 
 	device_lock(&dev->dev);
-	dev->error_state = result_data->state;
+	dev->error_state = state;
 
 	if (!dev->driver ||
 		!dev->driver->err_handler ||
@@ -75,22 +69,29 @@ static int report_error_detected(struct pci_dev *dev, void *data)
 			vote = PCI_ERS_RESULT_NONE;
 	} else {
 		err_handler = dev->driver->err_handler;
-		vote = err_handler->error_detected(dev, result_data->state);
+		vote = err_handler->error_detected(dev, state);
 		pci_uevent_ers(dev, PCI_ERS_RESULT_NONE);
 	}
 
-	result_data->result = merge_result(result_data->result, vote);
+	*result = merge_result(*result, vote);
 	device_unlock(&dev->dev);
 	return 0;
 }
 
+static int report_frozen_detected(struct pci_dev *dev, void *data)
+{
+	return report_error_detected(dev, pci_channel_io_frozen, data);
+}
+
+static int report_normal_detected(struct pci_dev *dev, void *data)
+{
+	return report_error_detected(dev, pci_channel_io_normal, data);
+}
+
 static int report_mmio_enabled(struct pci_dev *dev, void *data)
 {
-	pci_ers_result_t vote;
+	pci_ers_result_t vote, *result = data;
 	const struct pci_error_handlers *err_handler;
-	struct aer_broadcast_data *result_data;
-
-	result_data = (struct aer_broadcast_data *) data;
 
 	device_lock(&dev->dev);
 	if (!dev->driver ||
@@ -100,7 +101,7 @@ static int report_mmio_enabled(struct pci_dev *dev, void *data)
 
 	err_handler = dev->driver->err_handler;
 	vote = err_handler->mmio_enabled(dev);
-	result_data->result = merge_result(result_data->result, vote);
+	*result = merge_result(*result, vote);
 out:
 	device_unlock(&dev->dev);
 	return 0;
@@ -108,11 +109,8 @@ static int report_mmio_enabled(struct pci_dev *dev, void *data)
 
 static int report_slot_reset(struct pci_dev *dev, void *data)
 {
-	pci_ers_result_t vote;
+	pci_ers_result_t vote, *result = data;
 	const struct pci_error_handlers *err_handler;
-	struct aer_broadcast_data *result_data;
-
-	result_data = (struct aer_broadcast_data *) data;
 
 	device_lock(&dev->dev);
 	if (!dev->driver ||
@@ -122,7 +120,7 @@ static int report_slot_reset(struct pci_dev *dev, void *data)
 
 	err_handler = dev->driver->err_handler;
 	vote = err_handler->slot_reset(dev);
-	result_data->result = merge_result(result_data->result, vote);
+	*result = merge_result(*result, vote);
 out:
 	device_unlock(&dev->dev);
 	return 0;
@@ -189,39 +187,11 @@ static pci_ers_result_t reset_link(struct pci_dev *dev, u32 service)
 	return status;
 }
 
-/**
- * broadcast_error_message - handle message broadcast to downstream drivers
- * @dev: pointer to from where in a hierarchy message is broadcasted down
- * @state: error state
- * @error_mesg: message to print
- * @cb: callback to be broadcasted
- *
- * Invoked during error recovery process. Once being invoked, the content
- * of error severity will be broadcasted to all downstream drivers in a
- * hierarchy in question.
- */
-static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
-	enum pci_channel_state state,
-	char *error_mesg,
-	int (*cb)(struct pci_dev *, void *))
-{
-	struct aer_broadcast_data result_data;
-
-	pci_printk(KERN_DEBUG, dev, "broadcast %s message\n", error_mesg);
-	result_data.state = state;
-	if (cb == report_error_detected)
-		result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
-	else
-		result_data.result = PCI_ERS_RESULT_RECOVERED;
-
-	pci_walk_bus(dev->subordinate, cb, &result_data);
-	return result_data.result;
-}
-
 void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 		      u32 service)
 {
-	pci_ers_result_t status;
+	pci_ers_result_t status = PCI_ERS_RESULT_CAN_RECOVER;
+	struct pci_bus *bus;
 
 	/*
 	 * Error recovery runs on all subordinates of the first downstream port.
@@ -230,21 +200,23 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 	if (!(pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT ||
 	      pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM))
 		dev = dev->bus->self;
+	bus = dev->subordinate;
 
-	status = broadcast_error_message(dev,
-			state,
-			"error_detected",
-			report_error_detected);
+	pci_dbg(dev, "broadcast error_detected message\n");
+	if (state == pci_channel_io_frozen)
+		pci_walk_bus(bus, report_frozen_detected, &status);
+	else
+		pci_walk_bus(bus, report_normal_detected, &status);
 
 	if (state == pci_channel_io_frozen &&
 	    reset_link(dev, service) != PCI_ERS_RESULT_RECOVERED)
 		goto failed;
 
-	if (status == PCI_ERS_RESULT_CAN_RECOVER)
-		status = broadcast_error_message(dev,
-				state,
-				"mmio_enabled",
-				report_mmio_enabled);
+	if (status == PCI_ERS_RESULT_CAN_RECOVER) {
+		status = PCI_ERS_RESULT_RECOVERED;
+		pci_dbg(dev, "broadcast mmio_enabled message\n");
+		pci_walk_bus(bus, report_mmio_enabled, &status);
+	}
 
 	if (status == PCI_ERS_RESULT_NEED_RESET) {
 		/*
@@ -252,19 +224,16 @@ void pcie_do_recovery(struct pci_dev *dev, enum pci_channel_state state,
 		 * functions to reset slot before calling
 		 * drivers' slot_reset callbacks?
 		 */
-		status = broadcast_error_message(dev,
-				state,
-				"slot_reset",
-				report_slot_reset);
+		status = PCI_ERS_RESULT_RECOVERED;
+		pci_dbg(dev, "broadcast slot_reset message\n");
+		pci_walk_bus(bus, report_slot_reset, &status);
 	}
 
 	if (status != PCI_ERS_RESULT_RECOVERED)
 		goto failed;
 
-	broadcast_error_message(dev,
-				state,
-				"resume",
-				report_resume);
+	pci_dbg(dev, "broadcast resume message\n");
+	pci_walk_bus(bus, report_resume, &status);
 
 	pci_aer_clear_device_status(dev);
 	pci_cleanup_aer_uncorrect_error_status(dev);