[PATCH v16 8/9] PCI/DPC: Unify and plumb error handling into DPC

Oza Pawandeep
2018-05-11T10:43:27Z

DPC driver implements link_reset callback, and calls
pci_do_fatal_recovery().

Which follows standard path of ERR_FATAL recovery.

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

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 5e8857a..6af7595 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -354,7 +354,7 @@ 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 */
-void pcie_do_fatal_recovery(struct pci_dev *dev);
+void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service);
void pcie_do_nonfatal_recovery(struct pci_dev *dev);

bool pcie_wait_for_link(struct pci_dev *pdev, bool active);
diff --git a/drivers/pci/pcie/aer/aerdrv_core.c b/drivers/pci/pcie/aer/aerdrv_core.c
index fdfc474..36e622d 100644
--- a/drivers/pci/pcie/aer/aerdrv_core.c
+++ b/drivers/pci/pcie/aer/aerdrv_core.c
@@ -254,7 +254,7 @@ static void handle_error_source(struct pcie_device *aerdev,
} else if (info->severity == AER_NONFATAL)
pcie_do_nonfatal_recovery(dev);
else if (info->severity == AER_FATAL)
- pcie_do_fatal_recovery(dev);
+ pcie_do_fatal_recovery(dev, PCIE_PORT_SERVICE_AER);
}

#ifdef CONFIG_ACPI_APEI_PCIEAER
@@ -321,7 +321,7 @@ static void aer_recover_work_func(struct work_struct *work)
if (entry.severity == AER_NONFATAL)
pcie_do_nonfatal_recovery(pdev);
else if (entry.severity == AER_FATAL)
- pcie_do_fatal_recovery(pdev);
+ pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_AER);
pci_dev_put(pdev);
}
}
diff --git a/drivers/pci/pcie/dpc.c b/drivers/pci/pcie/dpc.c
index 80ec384..5680c13 100644
--- a/drivers/pci/pcie/dpc.c
+++ b/drivers/pci/pcie/dpc.c
@@ -73,29 +73,31 @@ static void dpc_wait_link_inactive(struct dpc_dev *dpc)
pcie_wait_for_link(pdev, false);
}

-static void dpc_work(struct work_struct *work)
+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;
- u16 cap = dpc->cap_pos, ctl;
-
- pci_lock_rescan_remove();
- list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
- bus_list) {
- pci_dev_get(dev);
- pci_dev_set_disconnected(dev, NULL);
- if (pci_has_subordinate(dev))
- pci_walk_bus(dev->subordinate,
- pci_dev_set_disconnected, NULL);
- pci_stop_and_remove_bus_device(dev);
- pci_dev_put(dev);
- }
- pci_unlock_rescan_remove();
-
+ struct dpc_dev *dpc;
+ struct pcie_device *pciedev;
+ struct device *devdpc;
+ u16 cap, ctl;
+
+ /*
+ * DPC disables the Link automatically in hardware, so it has
+ * already been reset by the time we get here.
+ */
+
+ devdpc = pcie_port_find_device(pdev, PCIE_PORT_SERVICE_DPC);
+ pciedev = to_pcie_device(devdpc);
+ dpc = get_service_data(pciedev);
+ cap = dpc->cap_pos;
+
+ /*
+ * Waiting until the link is inactive, then clearing DPC
+ * trigger status to allow the port to leave DPC.
+ */
dpc_wait_link_inactive(dpc);
+
if (dpc->rp_extensions && dpc_wait_rp_inactive(dpc))
- return;
+ return PCI_ERS_RESULT_DISCONNECT;
if (dpc->rp_extensions && dpc->rp_pio_status) {
pci_write_config_dword(pdev, cap + PCI_EXP_DPC_RP_PIO_STATUS,
dpc->rp_pio_status);
@@ -108,6 +110,17 @@ static void dpc_work(struct work_struct *work)
pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl);
pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL,
ctl | PCI_EXP_DPC_CTL_INT_EN);
+
+ return PCI_ERS_RESULT_RECOVERED;
+}
+
+static void dpc_work(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. */
+ pcie_do_fatal_recovery(pdev, PCIE_PORT_SERVICE_DPC);
}

static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
@@ -288,6 +301,7 @@ static struct pcie_port_service_driver dpcdriver = {
.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/err.c b/drivers/pci/pcie/err.c
index 33a16b1..29ff148 100644
--- a/drivers/pci/pcie/err.c
+++ b/drivers/pci/pcie/err.c
@@ -185,7 +185,7 @@ 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, u32 service)
{
struct pci_dev *udev;
pci_ers_result_t status;
@@ -200,7 +200,7 @@ static pci_ers_result_t reset_link(struct pci_dev *dev)
}

/* Use the aer driver of the component firstly */
- driver = pcie_port_find_service(udev, PCIE_PORT_SERVICE_AER);
+ driver = pcie_port_find_service(udev, service);

if (driver && driver->reset_link) {
status = driver->reset_link(udev);
@@ -287,7 +287,7 @@ static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
* followed by re-enumeration of devices.
*/

-void pcie_do_fatal_recovery(struct pci_dev *dev)
+void pcie_do_fatal_recovery(struct pci_dev *dev, u32 service)
{
struct pci_dev *udev;
struct pci_bus *parent;
@@ -313,7 +313,7 @@ void pcie_do_fatal_recovery(struct pci_dev *dev)
pci_dev_put(pdev);
}

- result = reset_link(udev);
+ result = reset_link(udev, service);

if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) {
/*
diff --git a/include/linux/aer.h b/include/linux/aer.h
index 8f87bbe..0c506fe 100644
--- a/include/linux/aer.h
+++ b/include/linux/aer.h
@@ -14,6 +14,7 @@
#define AER_NONFATAL 0
#define AER_FATAL 1
#define AER_CORRECTABLE 2
+#define DPC_FATAL 4

struct pci_dev;

--
2.7.4