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Commit 28eb27cf authored by Zhang, Yanmin's avatar Zhang, Yanmin Committed by Jesse Barnes
Browse files

PCI AER: support invalid error source IDs 



When the bus id part of error source id is equal to 0 or nosourceid=1,
make the kernel probe the AER status registers of all devices under the
root port to find the initial error reporter.

Reviewed-by: default avatarAndrew Patterson <andrew.patterson@hp.com>
Signed-off-by: default avatarZhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: default avatarJesse Barnes <jbarnes@virtuousgeek.org>
parent 70298c6e

Documentation/PCI/pcieaer-howto.txt

+4 −0
Original line number Diff line number Diff line
@@ -61,6 +61,10 @@ be initiated although firmwares have no _OSC support. To enable the 
walkaround, pls. add aerdriver.forceload=y to kernel boot parameter line

when booting kernel. Note that forceload=n by default.



nosourceid, another parameter of type bool, can be used when broken

hardware (mostly chipsets) has root ports that cannot obtain the reporting

source ID. nosourceid=n by default.



2.3 AER error output

When a PCI-E AER error is captured, an error message will be outputed to

console. If it's a correctable error, it is outputed as a warning.

drivers/pci/pcie/aer/aerdrv.h

+2 −0
Original line number Diff line number Diff line
@@ -58,6 +58,8 @@ struct header_log_regs { 
};



struct aer_err_info {

	struct pci_dev *dev;

	u16 id;

	int severity;			/* 0:NONFATAL | 1:FATAL | 2:COR */

	int flags;

	unsigned int status;		/* COR/UNCOR Error Status */

drivers/pci/pcie/aer/aerdrv_core.c

+116 −60
Original line number Diff line number Diff line
@@ -26,7 +26,9 @@ 
#include "aerdrv.h"



static int forceload;

static int nosourceid;

module_param(forceload, bool, 0);

module_param(nosourceid, bool, 0);



int pci_enable_pcie_error_reporting(struct pci_dev *dev)

{
@@ -143,34 +145,87 @@ static void set_downstream_devices_error_reporting(struct pci_dev *dev, 
	pci_walk_bus(dev->subordinate, set_device_error_reporting, &enable);

}



static int find_device_iter(struct device *device, void *data)

static inline int compare_device_id(struct pci_dev *dev,

			struct aer_err_info *e_info)

{

	struct pci_dev *dev;

	u16 id = *(unsigned long *)data;

	u8 secondary, subordinate, d_bus = id >> 8;



	if (device->bus == &pci_bus_type) {

		dev = to_pci_dev(device);

		if (id == ((dev->bus->number << 8) | dev->devfn)) {

	if (e_info->id == ((dev->bus->number << 8) | dev->devfn)) {

		/*

		 * Device ID match

		 */

			*(unsigned long*)data = (unsigned long)device;

		return 1;

	}



	return 0;

}



#define	PCI_BUS(x)	(((x) >> 8) & 0xff)



static int find_device_iter(struct pci_dev *dev, void *data)

{

	int pos;

	u32 status;

	u32 mask;

	u16 reg16;

	int result;

	struct aer_err_info *e_info = (struct aer_err_info *)data;



	/*

		 * If device is P2P, check if it is an upstream?

	 * When bus id is equal to 0, it might be a bad id

	 * reported by root port.

	 */

		if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {

			pci_read_config_byte(dev, PCI_SECONDARY_BUS,

				&secondary);

			pci_read_config_byte(dev, PCI_SUBORDINATE_BUS,

				&subordinate);

			if (d_bus >= secondary && d_bus <= subordinate) {

				*(unsigned long*)data = (unsigned long)device;

	if (!nosourceid && (PCI_BUS(e_info->id) != 0)) {

		result = compare_device_id(dev, e_info);

		if (result)

			e_info->dev = dev;

		return result;

	}



	/*

	 * Next is to check when bus id is equal to 0 or

	 * nosourceid==y. Some ports might lose the bus

	 * id of error source id. We check AER status

	 * registers to find the initial reporter.

	 */

	if (atomic_read(&dev->enable_cnt) == 0)

		return 0;

	pos = pci_find_capability(dev, PCI_CAP_ID_EXP);

	if (!pos)

		return 0;

	/* Check if AER is enabled */

	pci_read_config_word(dev, pos+PCI_EXP_DEVCTL, &reg16);

	if (!(reg16 & (

		PCI_EXP_DEVCTL_CERE |

		PCI_EXP_DEVCTL_NFERE |

		PCI_EXP_DEVCTL_FERE |

		PCI_EXP_DEVCTL_URRE)))

		return 0;

	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);

	if (!pos)

		return 0;



	status = 0;

	mask = 0;

	if (e_info->severity == AER_CORRECTABLE) {

		pci_read_config_dword(dev,

				pos + PCI_ERR_COR_STATUS,

				&status);

		pci_read_config_dword(dev,

				pos + PCI_ERR_COR_MASK,

				&mask);

		if (status & ERR_CORRECTABLE_ERROR_MASK & ~mask) {

			e_info->dev = dev;

			return 1;

		}

	} else {

		pci_read_config_dword(dev,

				pos + PCI_ERR_UNCOR_STATUS,

				&status);

		pci_read_config_dword(dev,

				pos + PCI_ERR_UNCOR_MASK,

				&mask);

		if (status & ERR_UNCORRECTABLE_ERROR_MASK & ~mask) {

			e_info->dev = dev;

			return 1;

		}

	}
@@ -180,33 +235,22 @@ static int find_device_iter(struct device *device, void *data) 
/**

 * find_source_device - search through device hierarchy for source device

 * @parent: pointer to Root Port pci_dev data structure

 * @id: device ID of agent who sends an error message to this Root Port

 * @err_info: including detailed error information such like id

 *

 * Invoked when error is detected at the Root Port.

 */

static struct device* find_source_device(struct pci_dev *parent, u16 id)

static void find_source_device(struct pci_dev *parent,

		struct aer_err_info *e_info)

{

	struct pci_dev *dev = parent;

	struct device *device;

	unsigned long device_addr;

	int status;

	int result;



	/* Is Root Port an agent that sends error message? */

	if (id == ((dev->bus->number << 8) | dev->devfn))

		return &dev->dev;



	do {

		device_addr = id;

 		if ((status = device_for_each_child(&dev->dev,

			&device_addr, find_device_iter))) {

			device = (struct device*)device_addr;

			dev = to_pci_dev(device);

			if (id == ((dev->bus->number << 8) | dev->devfn))

				return device;

		}

 	}while (status);

	result = find_device_iter(dev, e_info);

	if (result)

		return;



	return NULL;

	pci_walk_bus(parent->subordinate, find_device_iter, e_info);

}



static int report_error_detected(struct pci_dev *dev, void *data)
@@ -501,12 +545,12 @@ static pci_ers_result_t do_recovery(struct pcie_device *aerdev, 
 */

static void handle_error_source(struct pcie_device * aerdev,

	struct pci_dev *dev,

	struct aer_err_info info)

	struct aer_err_info *info)

{

	pci_ers_result_t status = 0;

	int pos;



	if (info.severity == AER_CORRECTABLE) {

	if (info->severity == AER_CORRECTABLE) {

		/*

		 * Correctable error does not need software intevention.

		 * No need to go through error recovery process.
@@ -514,9 +558,9 @@ static void handle_error_source(struct pcie_device * aerdev, 
		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);

		if (pos)

			pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS,

					info.status);

					info->status);

	} else {

		status = do_recovery(aerdev, dev, info.severity);

		status = do_recovery(aerdev, dev, info->severity);

		if (status == PCI_ERS_RESULT_RECOVERED) {

			dev_printk(KERN_DEBUG, &dev->dev, "AER driver "

				   "successfully recovered\n");
@@ -673,10 +717,16 @@ static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info) 
static void aer_isr_one_error(struct pcie_device *p_device,

		struct aer_err_source *e_src)

{

	struct device *s_device;

	struct aer_err_info e_info = {0, 0, 0,};

	struct aer_err_info *e_info;

	int i;

	u16 id;



	/* struct aer_err_info might be big, so we allocate it with slab */

	e_info = kmalloc(sizeof(struct aer_err_info), GFP_KERNEL);

	if (e_info == NULL) {

		dev_printk(KERN_DEBUG, &p_device->port->dev,

			"Can't allocate mem when processing AER errors\n");

		return;

	}



	/*

	 * There is a possibility that both correctable error and
@@ -688,31 +738,37 @@ static void aer_isr_one_error(struct pcie_device *p_device, 
		if (!(e_src->status & i))

			continue;



		memset(e_info, 0, sizeof(struct aer_err_info));



		/* Init comprehensive error information */

		if (i & PCI_ERR_ROOT_COR_RCV) {

			id = ERR_COR_ID(e_src->id);

			e_info.severity = AER_CORRECTABLE;

			e_info->id = ERR_COR_ID(e_src->id);

			e_info->severity = AER_CORRECTABLE;

		} else {

			id = ERR_UNCOR_ID(e_src->id);

			e_info.severity = ((e_src->status >> 6) & 1);

			e_info->id = ERR_UNCOR_ID(e_src->id);

			e_info->severity = ((e_src->status >> 6) & 1);

		}

		if (e_src->status &

			(PCI_ERR_ROOT_MULTI_COR_RCV |

			 PCI_ERR_ROOT_MULTI_UNCOR_RCV))

			e_info.flags |= AER_MULTI_ERROR_VALID_FLAG;

		if (!(s_device = find_source_device(p_device->port, id))) {

			e_info->flags |= AER_MULTI_ERROR_VALID_FLAG;



		find_source_device(p_device->port, e_info);

		if (e_info->dev == NULL) {

			printk(KERN_DEBUG "%s->can't find device of ID%04x\n",

				__func__, id);

				__func__, e_info->id);

			continue;

		}

		if (get_device_error_info(to_pci_dev(s_device), &e_info) ==

		if (get_device_error_info(e_info->dev, e_info) ==

				AER_SUCCESS) {

			aer_print_error(to_pci_dev(s_device), &e_info);

			aer_print_error(e_info->dev, e_info);

			handle_error_source(p_device,

				to_pci_dev(s_device),

				e_info->dev,

				e_info);

		}

	}



	kfree(e_info);

}



/**