Commit 57908622 authored by Qiuxu Zhuo's avatar Qiuxu Zhuo Committed by Bjorn Helgaas
Browse files

PCI/ERR: Recover from RCiEP AER errors 



Add support for handling AER errors detected by Root Complex Integrated
Endpoints (RCiEPs).  These errors are signaled to software natively via a
Root Complex Event Collector (RCEC) or non-natively via ACPI APEI if the
platform retains control of AER or uses a non-standard RCEC-like device.

When recovering from RCiEP errors, the Root Error Command and Status
registers are in the AER Capability of an associated RCEC (if any), not in
a Root Port.  In the non-native case, the platform is responsible for those
registers and we can't touch them.

[bhelgaas: commit log, etc]
Co-developed-by: default avatarSean V Kelley <sean.v.kelley@intel.com>
Link: https://lore.kernel.org/r/20201121001036.8560-13-sean.v.kelley@intel.com


Signed-off-by: default avatarSean V Kelley <sean.v.kelley@intel.com>
Signed-off-by: default avatarQiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 507b460f

drivers/pci/pcie/aer.c

+19 −5
Original line number Diff line number Diff line
@@ -1359,8 +1359,8 @@ static int aer_probe(struct pcie_device *dev) 
}



/**

 * aer_root_reset - reset Root Port hierarchy or RCEC

 * @dev: pointer to Root Port or RCEC

 * aer_root_reset - reset Root Port hierarchy, RCEC, or RCiEP

 * @dev: pointer to Root Port, RCEC, or RCiEP

 *

 * Invoked by Port Bus driver when performing reset.

 */
@@ -1373,8 +1373,22 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) 
	u32 reg32;

	int rc;



	root = dev;	/* device with Root Error registers */

	aer = root->aer_cap;

	/*

	 * Only Root Ports and RCECs have AER Root Command and Root Status

	 * registers.  If "dev" is an RCiEP, the relevant registers are in

	 * the RCEC.

	 */

	if (type == PCI_EXP_TYPE_RC_END)

		root = dev->rcec;

	else

		root = dev;



	/*

	 * If the platform retained control of AER, an RCiEP may not have

	 * an RCEC visible to us, so dev->rcec ("root") may be NULL.  In

	 * that case, firmware is responsible for these registers.

	 */

	aer = root ? root->aer_cap : 0;



	if ((host->native_aer || pcie_ports_native) && aer) {

		/* Disable Root's interrupt in response to error messages */
@@ -1383,7 +1397,7 @@ static pci_ers_result_t aer_root_reset(struct pci_dev *dev) 
		pci_write_config_dword(root, aer + PCI_ERR_ROOT_COMMAND, reg32);

	}



	if (type == PCI_EXP_TYPE_RC_EC) {

	if (type == PCI_EXP_TYPE_RC_EC || type == PCI_EXP_TYPE_RC_END) {

		if (pcie_has_flr(dev)) {

			rc = pcie_flr(dev);

			pci_info(dev, "has been reset (%d)\n", rc);

drivers/pci/pcie/err.c

+8 −7
Original line number Diff line number Diff line
@@ -148,7 +148,7 @@ out: 


/**

 * pci_walk_bridge - walk bridges potentially AER affected

 * @bridge:	bridge which may be a Port or an RCEC

 * @bridge:	bridge which may be a Port, an RCEC, or an RCiEP

 * @cb:		callback to be called for each device found

 * @userdata:	arbitrary pointer to be passed to callback

 *
@@ -156,8 +156,8 @@ out: 
 * any bridged devices on buses under this bus.  Call the provided callback

 * on each device found.

 *

 * If the device provided has no subordinate bus, e.g., an RCEC, call the

 * callback on the device itself.

 * If the device provided has no subordinate bus, e.g., an RCEC or RCiEP,

 * call the callback on the device itself.

 */

static void pci_walk_bridge(struct pci_dev *bridge,

			    int (*cb)(struct pci_dev *, void *),
@@ -179,9 +179,9 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, 
	struct pci_host_bridge *host = pci_find_host_bridge(dev->bus);



	/*

	 * If the error was detected by a Root Port, Downstream Port, or

	 * RCEC, recovery runs on the device itself.  For Ports, that also

	 * includes any subordinate devices.

	 * If the error was detected by a Root Port, Downstream Port, RCEC,

	 * or RCiEP, recovery runs on the device itself.  For Ports, that

	 * also includes any subordinate devices.

	 *

	 * If it was detected by another device (Endpoint, etc), recovery

	 * runs on the device and anything else under the same Port, i.e.,
@@ -189,7 +189,8 @@ pci_ers_result_t pcie_do_recovery(struct pci_dev *dev, 
	 */

	if (type == PCI_EXP_TYPE_ROOT_PORT ||

	    type == PCI_EXP_TYPE_DOWNSTREAM ||

	    type == PCI_EXP_TYPE_RC_EC)

	    type == PCI_EXP_TYPE_RC_EC ||

	    type == PCI_EXP_TYPE_RC_END)

		bridge = dev;

	else

		bridge = pci_upstream_bridge(dev);

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