Current DPC driver does not do recovery, e.g. calling end-point's driver's
callbacks, which sanitize the sw.

DPC driver implements link_reset callback, and calls pci_do_recovery.

Signed-off-by: Oza Pawandeep <p...@codeaurora.org>

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 665ff6c..3b79593 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -343,8 +343,12 @@ static inline resource_size_t 
pci_resource_alignment(struct pci_dev *dev,
 void pci_enable_acs(struct pci_dev *dev);
 
 /* PCI error reporting and recovery */
+#define DPC_FATAL      4
+
 void pci_do_recovery(struct pci_dev *dev, int severity);
 
+
+
 #ifdef CONFIG_PCIE_PTM
 void pci_ptm_init(struct pci_dev *dev);
 #else
diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
index 2d976a6..b5c9fbd 100644
--- a/drivers/pci/pcie/pcie-dpc.c
+++ b/drivers/pci/pcie/pcie-dpc.c
@@ -15,6 +15,9 @@
 #include <linux/pci.h>
 #include <linux/pcieport_if.h>
 #include "../pci.h"
+#include "portdrv.h"
+
+static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev);
 
 struct rp_pio_header_log_regs {
        u32 dw0;
@@ -67,6 +70,60 @@ struct dpc_dev {
        "Memory Request Completion Timeout",             /* Bit Position 18 */
 };
 
+static int find_dpc_dev_iter(struct device *device, void *data)
+{
+       struct pcie_port_service_driver *service_driver;
+       struct device **dev;
+
+       dev = (struct device **) data;
+
+       if (device->bus == &pcie_port_bus_type && device->driver) {
+               service_driver = to_service_driver(device->driver);
+               if (service_driver->service == PCIE_PORT_SERVICE_DPC) {
+                       *dev = device;
+                       return 1;
+               }
+       }
+
+       return 0;
+}
+
+static struct device *pci_find_dpc_dev(struct pci_dev *pdev)
+{
+       struct device *dev = NULL;
+
+       device_for_each_child(&pdev->dev, &dev, find_dpc_dev_iter);
+
+       return dev;
+}
+
+static int find_dpc_service_iter(struct device *device, void *data)
+{
+       struct pcie_port_service_driver *service_driver, **drv;
+
+       drv = (struct pcie_port_service_driver **) data;
+
+       if (device->bus == &pcie_port_bus_type && device->driver) {
+               service_driver = to_service_driver(device->driver);
+               if (service_driver->service == PCIE_PORT_SERVICE_DPC) {
+                       *drv = service_driver;
+                       return 1;
+               }
+       }
+
+       return 0;
+}
+
+struct pcie_port_service_driver *pci_find_dpc_service(struct pci_dev *dev)
+{
+       struct pcie_port_service_driver *drv = NULL;
+
+       device_for_each_child(&dev->dev, &drv, find_dpc_service_iter);
+
+       return drv;
+}
+EXPORT_SYMBOL(pci_find_dpc_service);
+
 static int dpc_wait_rp_inactive(struct dpc_dev *dpc)
 {
        unsigned long timeout = jiffies + HZ;
@@ -104,11 +161,23 @@ static void dpc_wait_link_inactive(struct dpc_dev *dpc)
                dev_warn(dev, "Link state not disabled for DPC event\n");
 }
 
-static void interrupt_event_handler(struct work_struct *work)
+/**
+ * dpc_reset_link - reset link DPC  routine
+ * @dev: pointer to Root Port's pci_dev data structure
+ *
+ * Invoked by Port Bus driver when performing link reset at Root Port.
+ */
+static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
 {
-       struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
-       struct pci_dev *dev, *temp, *pdev = dpc->dev->port;
        struct pci_bus *parent = pdev->subordinate;
+       struct pci_dev *dev, *temp;
+       struct dpc_dev *dpc;
+       struct pcie_device *pciedev;
+       struct device *devdpc;
+
+       devdpc = pci_find_dpc_dev(pdev);
+       pciedev = to_pcie_device(devdpc);
+       dpc = get_service_data(pciedev);
 
        pci_lock_rescan_remove();
        list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
@@ -125,7 +194,7 @@ static void interrupt_event_handler(struct work_struct 
*work)
 
        dpc_wait_link_inactive(dpc);
        if (dpc->rp && dpc_wait_rp_inactive(dpc))
-               return;
+               return PCI_ERS_RESULT_DISCONNECT;
        if (dpc->rp && dpc->rp_pio_status) {
                pci_write_config_dword(pdev,
                                      dpc->cap_pos + PCI_EXP_DPC_RP_PIO_STATUS,
@@ -135,6 +204,17 @@ static void interrupt_event_handler(struct work_struct 
*work)
 
        pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
                PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
+
+       return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void interrupt_event_handler(struct work_struct *work)
+{
+       struct dpc_dev *dpc = container_of(work, struct dpc_dev, work);
+       struct pci_dev *pdev = dpc->dev->port;
+
+       /* From DPC point of view error is always FATAL. */
+       pci_do_recovery(pdev, DPC_FATAL);
 }
 
 static void dpc_rp_pio_print_tlp_header(struct device *dev,
@@ -339,6 +419,7 @@ static void dpc_remove(struct pcie_device *dev)
        .service        = PCIE_PORT_SERVICE_DPC,
        .probe          = dpc_probe,
        .remove         = dpc_remove,
+       .reset_link     = dpc_reset_link,
 };
 
 static int __init dpc_service_init(void)
diff --git a/drivers/pci/pcie/pcie-err.c b/drivers/pci/pcie/pcie-err.c
index 8318c84..05385c0 100644
--- a/drivers/pci/pcie/pcie-err.c
+++ b/drivers/pci/pcie/pcie-err.c
@@ -19,6 +19,7 @@
 #include <linux/aer.h>
 #include <linux/pcieport_if.h>
 #include "portdrv.h"
+#include "./../pci.h"
 
 static DEFINE_MUTEX(pci_err_recovery_lock);
 
@@ -181,7 +182,7 @@ static pci_ers_result_t default_reset_link(struct pci_dev 
*dev)
        return PCI_ERS_RESULT_RECOVERED;
 }
 
-static pci_ers_result_t reset_link(struct pci_dev *dev)
+static pci_ers_result_t reset_link(struct pci_dev *dev, int severity)
 {
        struct pci_dev *udev;
        pci_ers_result_t status;
@@ -195,9 +196,17 @@ static pci_ers_result_t reset_link(struct pci_dev *dev)
                udev = dev->bus->self;
        }
 
+
+       /* Use the service driver of the component firstly */
+#if IS_ENABLED(CONFIG_PCIE_DPC)
+       if (severity == DPC_FATAL)
+               driver = pci_find_dpc_service(udev);
+#endif
 #if IS_ENABLED(CONFIG_PCIEAER)
-       /* Use the aer driver of the component firstly */
-       driver = pci_find_aer_service(udev);
+       if ((severity == AER_FATAL) ||
+           (severity == AER_NONFATAL) ||
+           (severity == AER_CORRECTABLE))
+               driver = pci_find_aer_service(udev);
 #endif
 
        if (driver && driver->reset_link) {
@@ -287,7 +296,8 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
 
        mutex_lock(&pci_err_recovery_lock);
 
-       if (severity == AER_FATAL)
+       if ((severity == AER_FATAL) ||
+           (severity == DPC_FATAL))
                state = pci_channel_io_frozen;
        else
                state = pci_channel_io_normal;
@@ -297,8 +307,9 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
                        "error_detected",
                        report_error_detected);
 
-       if (severity == AER_FATAL) {
-               result = reset_link(dev);
+       if ((severity == AER_FATAL) ||
+           (severity == DPC_FATAL)) {
+               result = reset_link(dev, severity);
                if (result != PCI_ERS_RESULT_RECOVERED)
                        goto failed;
        }
@@ -335,6 +346,6 @@ void pci_do_recovery(struct pci_dev *dev, int severity)
 
 failed:
        /* TODO: Should kernel panic here? */
-       dev_info(&dev->dev, "Device recovery failed\n");
        mutex_unlock(&pci_err_recovery_lock);
+       dev_info(&dev->dev, "Device recovery failed\n");
 }
diff --git a/drivers/pci/pcie/portdrv.h b/drivers/pci/pcie/portdrv.h
index 4f1992d..b013e24 100644
--- a/drivers/pci/pcie/portdrv.h
+++ b/drivers/pci/pcie/portdrv.h
@@ -80,4 +80,5 @@ static inline void pcie_port_platform_notify(struct pci_dev 
*port, int *mask){}
 #endif /* !CONFIG_ACPI */
 
 struct pcie_port_service_driver *pci_find_aer_service(struct pci_dev *dev);
+struct pcie_port_service_driver *pci_find_dpc_service(struct pci_dev *dev);
 #endif /* _PORTDRV_H_ */
-- 
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm 
Technologies, Inc.,
a Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux 
Foundation Collaborative Project.

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