diff mbox

[v9,4/7] PCI/DPC: Unify and plumb error handling into DPC

Message ID 1519285571-5634-5-git-send-email-poza@codeaurora.org (mailing list archive)
State New, archived
Delegated to: Bjorn Helgaas
Headers show

Commit Message

Oza Pawandeep Feb. 22, 2018, 7:46 a.m. UTC 
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 <poza@codeaurora.org>

Comments

Randy Dunlap Feb. 22, 2018, 7:23 p.m. UTC | #1 
On 02/21/2018 11:46 PM, Oza Pawandeep wrote:
> 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.

Hi,
What does DPC mean?

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

> diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
> index 38e40c6..208b427 100644
> --- a/drivers/pci/pcie/pcie-dpc.c
> +++ b/drivers/pci/pcie/pcie-dpc.c

> @@ -82,12 +137,25 @@ static void dpc_wait_link_inactive(struct dpc_dev *dpc)
>  		dev_warn(dev, "Link state not disabled for DPC event\n");
>  }
>  
> +/**
> + * dpc_reset_link - reset link DPC  routine
 + * @dev: pointer to Root Port's pci_dev data structure

   * @pdev: ...

> + *
> + * Invoked by Port Bus driver when performing link reset at Root Port.
> + */
> +static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
>  {

You can use 'make W=1 ...' to find kernel-doc warnings like this.

thanks,
Oza Pawandeep Feb. 23, 2018, 5:20 a.m. UTC | #2 
On 2018-02-23 00:53, Randy Dunlap wrote:
> On 02/21/2018 11:46 PM, Oza Pawandeep wrote:
>> 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.
> 
> Hi,
> What does DPC mean?
> 

DPC (Downstream port containment) is PCIe RP or Switch feature, which if 
detects FATAL error messages
halts the outgoing traffic, and PCIe link reset and quiescence 
activities are taken care by HW, and recovery is made.
followed by that; normal operation can be resumed.

>> Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
>> 
> 
>> diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
>> index 38e40c6..208b427 100644
>> --- a/drivers/pci/pcie/pcie-dpc.c
>> +++ b/drivers/pci/pcie/pcie-dpc.c
> 
>> @@ -82,12 +137,25 @@ static void dpc_wait_link_inactive(struct dpc_dev 
>> *dpc)
>>  		dev_warn(dev, "Link state not disabled for DPC event\n");
>>  }
>> 
>> +/**
>> + * dpc_reset_link - reset link DPC  routine
>  + * @dev: pointer to Root Port's pci_dev data structure
> 
>    * @pdev: ...
> 
>> + *
>> + * Invoked by Port Bus driver when performing link reset at Root 
>> Port.
>> + */
>> +static pci_ers_result_t dpc_reset_link(struct pci_dev *pdev)
>>  {
> 
> You can use 'make W=1 ...' to find kernel-doc warnings like this.
> 

sure thanks for this tip.

ps: I am going to post v11 to address some comments.
> thanks,
diff mbox

Patch

diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index a5a79f0..124f42e 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -343,6 +343,8 @@  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_PCIEASPM
diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c
index 38e40c6..208b427 100644
--- a/drivers/pci/pcie/pcie-dpc.c
+++ b/drivers/pci/pcie/pcie-dpc.c
@@ -13,6 +13,7 @@ 
 #include <linux/pcieport_if.h>
 #include "../pci.h"
 #include "aer/aerdrv.h"
+#include "portdrv.h"
 
 struct dpc_dev {
 	struct pcie_device	*dev;
@@ -45,6 +46,60 @@  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;
@@ -82,12 +137,25 @@  static void dpc_wait_link_inactive(struct dpc_dev *dpc)
 		dev_warn(dev, "Link state not disabled for DPC event\n");
 }
 
-static void dpc_work(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;
-	u16 cap = dpc->cap_pos, ctl;
+	struct pci_dev *dev, *temp;
+	struct dpc_dev *dpc;
+	struct pcie_device *pciedev;
+	struct device *devdpc;
+	u16 cap, ctl;
+
+	devdpc = pci_find_dpc_dev(pdev);
+	pciedev = to_pcie_device(devdpc);
+	dpc = get_service_data(pciedev);
+	cap = dpc->cap_pos;
 
 	pci_lock_rescan_remove();
 	list_for_each_entry_safe_reverse(dev, temp, &parent->devices,
@@ -104,21 +172,31 @@  static void dpc_work(struct work_struct *work)
 
 	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);
 		dpc->rp_pio_status = 0;
 	}
 
-	pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS,
+	pci_write_config_word(pdev, dpc->cap_pos + PCI_EXP_DPC_STATUS,
 		PCI_EXP_DPC_STATUS_TRIGGER | PCI_EXP_DPC_STATUS_INTERRUPT);
 
 	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);
+				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. */
+	pci_do_recovery(pdev, DPC_FATAL);
+}
 static void dpc_process_rp_pio_error(struct dpc_dev *dpc)
 {
 	struct device *dev = &dpc->dev->device;
@@ -297,6 +375,7 @@  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..6844347 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;
@@ -297,10 +307,14 @@  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;
+		else if (severity == DPC_FATAL)
+			goto resume;
+
 	}
 
 	if (status == PCI_ERS_RESULT_CAN_RECOVER)
@@ -324,6 +338,7 @@  void pci_do_recovery(struct pci_dev *dev, int severity)
 	if (status != PCI_ERS_RESULT_RECOVERED)
 		goto failed;
 
+resume:
 	broadcast_error_message(dev,
 				state,
 				"resume",
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_ */