Support for PCI Express reset type in EEH
Mike Mason
mmlnx at us.ibm.com
Wed Jul 15 04:35:11 EST 2009
By default, EEH does what's known as a "hot reset" during error recovery of a PCI Express device. We've found a case where the device needs a "fundamental reset" to recover properly. The current PCI error recovery and EEH frameworks do not support this distinction.
The attached patch (courtesy of Richard Lary) implements a reset type callback that can be used to determine what type of reset a device requires. It is backwards compatible with all other drivers that implement PCI error recovery callbacks. Only drivers that require a fundamental reset need to be changed. So far we're only aware of one driver that has the requirement (qla2xxx). The patch touches mostly EEH and pseries code, but does require a couple of minor additions to the overall PCI error recovery framework.
Signed-off-by: Mike Mason <mmlnx at us.ibm.com>
--- a/arch/powerpc/include/asm/ppc-pci.h 2009-06-09 20:05:27.000000000 -0700
+++ b/arch/powerpc/include/asm/ppc-pci.h 2009-07-13 16:12:31.000000000 -0700
@@ -90,7 +90,9 @@ int rtas_pci_enable(struct pci_dn *pdn,
*
* Returns a non-zero value if the reset failed.
*/
-int rtas_set_slot_reset (struct pci_dn *);
+#define HOT_RESET 1
+#define FUNDAMENTAL_RESET 3
+int rtas_set_slot_reset (struct pci_dn *, int reset_type);
int eeh_wait_for_slot_status(struct pci_dn *pdn, int max_wait_msecs);
/**
--- a/arch/powerpc/platforms/pseries/eeh.c 2009-06-09 20:05:27.000000000 -0700
+++ b/arch/powerpc/platforms/pseries/eeh.c 2009-07-13 16:27:27.000000000 -0700
@@ -666,7 +666,7 @@ rtas_pci_enable(struct pci_dn *pdn, int
/**
* rtas_pci_slot_reset - raises/lowers the pci #RST line
* @pdn pci device node
- * @state: 1/0 to raise/lower the #RST
+ * @state: 1/3/0 to raise hot-reset/fundamental-reset/lower the #RST
*
* Clear the EEH-frozen condition on a slot. This routine
* asserts the PCI #RST line if the 'state' argument is '1',
@@ -742,9 +742,9 @@ int pcibios_set_pcie_reset_state(struct
* Return 0 if success, else a non-zero value.
*/
-static void __rtas_set_slot_reset(struct pci_dn *pdn)
+static void __rtas_set_slot_reset(struct pci_dn *pdn, int reset_type)
{
- rtas_pci_slot_reset (pdn, 1);
+ rtas_pci_slot_reset (pdn, reset_type);
/* The PCI bus requires that the reset be held high for at least
* a 100 milliseconds. We wait a bit longer 'just in case'. */
@@ -766,13 +766,13 @@ static void __rtas_set_slot_reset(struct
msleep (PCI_BUS_SETTLE_TIME_MSEC);
}
-int rtas_set_slot_reset(struct pci_dn *pdn)
+int rtas_set_slot_reset(struct pci_dn *pdn, int reset_type)
{
int i, rc;
/* Take three shots at resetting the bus */
for (i=0; i<3; i++) {
- __rtas_set_slot_reset(pdn);
+ __rtas_set_slot_reset(pdn, reset_type);
rc = eeh_wait_for_slot_status(pdn, PCI_BUS_RESET_WAIT_MSEC);
if (rc == 0)
--- a/arch/powerpc/platforms/pseries/eeh_driver.c 2009-07-13 14:25:24.000000000 -0700
+++ b/arch/powerpc/platforms/pseries/eeh_driver.c 2009-07-13 16:39:16.000000000 -0700
@@ -115,6 +115,34 @@ static void eeh_enable_irq(struct pci_de
/* ------------------------------------------------------- */
/**
+ * eeh_query_reset_type - query each device driver for reset type
+ *
+ * Query each device driver for special reset type if required
+ * merge the device driver responses. Cumulative response
+ * passed back in "userdata".
+ */
+
+static int eeh_query_reset_type(struct pci_dev *dev, void *userdata)
+{
+ enum pci_ers_result rc, *res = userdata;
+ struct pci_driver *driver = dev->driver;
+
+ if (!driver)
+ return 0;
+
+ if (!driver->err_handler ||
+ !driver->err_handler->reset_type)
+ return 0;
+
+ rc = driver->err_handler->reset_type (dev);
+
+ /* A driver that needs a special reset trumps all others */
+ if (rc == PCI_ERS_RESULT_FUNDAMENTAL_RESET ) *res = rc;
+
+ return 0;
+}
+
+/**
* eeh_report_error - report pci error to each device driver
*
* Report an EEH error to each device driver, collect up and
@@ -282,9 +310,12 @@ static int eeh_report_failure(struct pci
* @pe_dn: pointer to a "Partionable Endpoint" device node.
* This is the top-level structure on which pci
* bus resets can be performed.
+ *
+ * reset_type: some devices may require type other than default hot reset.
*/
-static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
+static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus,
+ int reset_type)
{
struct device_node *dn;
int cnt, rc;
@@ -298,7 +329,7 @@ static int eeh_reset_device (struct pci_
/* Reset the pci controller. (Asserts RST#; resets config space).
* Reconfigure bridges and devices. Don't try to bring the system
* up if the reset failed for some reason. */
- rc = rtas_set_slot_reset(pe_dn);
+ rc = rtas_set_slot_reset(pe_dn, reset_type);
if (rc)
return rc;
@@ -343,6 +374,7 @@ struct pci_dn * handle_eeh_events (struc
struct pci_dn *frozen_pdn;
struct pci_bus *frozen_bus;
int rc = 0;
+ int reset_type = HOT_RESET;
enum pci_ers_result result = PCI_ERS_RESULT_NONE;
const char *location, *pci_str, *drv_str;
@@ -400,10 +432,16 @@ struct pci_dn * handle_eeh_events (struc
/* Walk the various device drivers attached to this slot through
* a reset sequence, giving each an opportunity to do what it needs
- * to accomplish the reset. Each child gets a report of the
- * status ... if any child can't handle the reset, then the entire
- * slot is dlpar removed and added.
+ * to accomplish the reset. Query device driver for special reset
+ * requiements. Report eeh error to each child with cumulative
+ * result status... if any child can't handle the reset,
+ * then the entire slot is dlpar removed and added.
*/
+ pci_walk_bus(frozen_bus, eeh_query_reset_type, &result);
+ if ( result == PCI_ERS_RESULT_FUNDAMENTAL_RESET )
+ reset_type = FUNDAMENTAL_RESET;
+
+ result = PCI_ERS_RESULT_NONE;
pci_walk_bus(frozen_bus, eeh_report_error, &result);
/* Get the current PCI slot state. This can take a long time,
@@ -425,7 +463,8 @@ struct pci_dn * handle_eeh_events (struc
* go down willingly, without panicing the system.
*/
if (result == PCI_ERS_RESULT_NONE) {
- rc = eeh_reset_device(frozen_pdn, frozen_bus);
+ rc = eeh_reset_device(frozen_pdn, frozen_bus, reset_type);
+
if (rc) {
printk(KERN_WARNING "EEH: Unable to reset, rc=%d\n", rc);
goto hard_fail;
@@ -466,7 +505,7 @@ struct pci_dn * handle_eeh_events (struc
/* If any device called out for a reset, then reset the slot */
if (result == PCI_ERS_RESULT_NEED_RESET) {
- rc = eeh_reset_device(frozen_pdn, NULL);
+ rc = eeh_reset_device(frozen_pdn, NULL, reset_type);
if (rc) {
printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc);
goto hard_fail;
--- a/include/linux/pci.h 2009-07-13 14:25:37.000000000 -0700
+++ b/include/linux/pci.h 2009-07-13 16:12:31.000000000 -0700
@@ -446,6 +446,9 @@ enum pci_ers_result {
/* Device driver is fully recovered and operational */
PCI_ERS_RESULT_RECOVERED = (__force pci_ers_result_t) 5,
+
+ /* Device driver requires fundamental reset to recover */
+ PCI_ERS_RESULT_FUNDAMENTAL_RESET = (__force pci_ers_result_t) 6,
};
/* PCI bus error event callbacks */
@@ -465,6 +468,9 @@ struct pci_error_handlers {
/* Device driver may resume normal operations */
void (*resume)(struct pci_dev *dev);
+
+ /* PCI slot requires special reset type for recovery */
+ pci_ers_result_t (*reset_type)(struct pci_dev *dev);
};
/* ---------------------------------------------------------------- */
--- a/arch/powerpc/include/asm/ppc-pci.h 2009-06-09 20:05:27.000000000 -0700
+++ b/arch/powerpc/include/asm/ppc-pci.h 2009-07-13 16:12:31.000000000 -0700
@@ -90,7 +90,9 @@ int rtas_pci_enable(struct pci_dn *pdn,
*
* Returns a non-zero value if the reset failed.
*/
-int rtas_set_slot_reset (struct pci_dn *);
+#define HOT_RESET 1
+#define FUNDAMENTAL_RESET 3
+int rtas_set_slot_reset (struct pci_dn *, int reset_type);
int eeh_wait_for_slot_status(struct pci_dn *pdn, int max_wait_msecs);
/**
--- a/arch/powerpc/platforms/pseries/eeh.c 2009-06-09 20:05:27.000000000 -0700
+++ b/arch/powerpc/platforms/pseries/eeh.c 2009-07-13 16:27:27.000000000 -0700
@@ -666,7 +666,7 @@ rtas_pci_enable(struct pci_dn *pdn, int
/**
* rtas_pci_slot_reset - raises/lowers the pci #RST line
* @pdn pci device node
- * @state: 1/0 to raise/lower the #RST
+ * @state: 1/3/0 to raise hot-reset/fundamental-reset/lower the #RST
*
* Clear the EEH-frozen condition on a slot. This routine
* asserts the PCI #RST line if the 'state' argument is '1',
@@ -742,9 +742,9 @@ int pcibios_set_pcie_reset_state(struct
* Return 0 if success, else a non-zero value.
*/
-static void __rtas_set_slot_reset(struct pci_dn *pdn)
+static void __rtas_set_slot_reset(struct pci_dn *pdn, int reset_type)
{
- rtas_pci_slot_reset (pdn, 1);
+ rtas_pci_slot_reset (pdn, reset_type);
/* The PCI bus requires that the reset be held high for at least
* a 100 milliseconds. We wait a bit longer 'just in case'. */
@@ -766,13 +766,13 @@ static void __rtas_set_slot_reset(struct
msleep (PCI_BUS_SETTLE_TIME_MSEC);
}
-int rtas_set_slot_reset(struct pci_dn *pdn)
+int rtas_set_slot_reset(struct pci_dn *pdn, int reset_type)
{
int i, rc;
/* Take three shots at resetting the bus */
for (i=0; i<3; i++) {
- __rtas_set_slot_reset(pdn);
+ __rtas_set_slot_reset(pdn, reset_type);
rc = eeh_wait_for_slot_status(pdn, PCI_BUS_RESET_WAIT_MSEC);
if (rc == 0)
--- a/arch/powerpc/platforms/pseries/eeh_driver.c 2009-07-13 14:25:24.000000000 -0700
+++ b/arch/powerpc/platforms/pseries/eeh_driver.c 2009-07-13 16:39:16.000000000 -0700
@@ -115,6 +115,34 @@ static void eeh_enable_irq(struct pci_de
/* ------------------------------------------------------- */
/**
+ * eeh_query_reset_type - query each device driver for reset type
+ *
+ * Query each device driver for special reset type if required
+ * merge the device driver responses. Cumulative response
+ * passed back in "userdata".
+ */
+
+static int eeh_query_reset_type(struct pci_dev *dev, void *userdata)
+{
+ enum pci_ers_result rc, *res = userdata;
+ struct pci_driver *driver = dev->driver;
+
+ if (!driver)
+ return 0;
+
+ if (!driver->err_handler ||
+ !driver->err_handler->reset_type)
+ return 0;
+
+ rc = driver->err_handler->reset_type (dev);
+
+ /* A driver that needs a special reset trumps all others */
+ if (rc == PCI_ERS_RESULT_FUNDAMENTAL_RESET ) *res = rc;
+
+ return 0;
+}
+
+/**
* eeh_report_error - report pci error to each device driver
*
* Report an EEH error to each device driver, collect up and
@@ -282,9 +310,12 @@ static int eeh_report_failure(struct pci
* @pe_dn: pointer to a "Partionable Endpoint" device node.
* This is the top-level structure on which pci
* bus resets can be performed.
+ *
+ * reset_type: some devices may require type other than default hot reset.
*/
-static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus)
+static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus,
+ int reset_type)
{
struct device_node *dn;
int cnt, rc;
@@ -298,7 +329,7 @@ static int eeh_reset_device (struct pci_
/* Reset the pci controller. (Asserts RST#; resets config space).
* Reconfigure bridges and devices. Don't try to bring the system
* up if the reset failed for some reason. */
- rc = rtas_set_slot_reset(pe_dn);
+ rc = rtas_set_slot_reset(pe_dn, reset_type);
if (rc)
return rc;
@@ -343,6 +374,7 @@ struct pci_dn * handle_eeh_events (struc
struct pci_dn *frozen_pdn;
struct pci_bus *frozen_bus;
int rc = 0;
+ int reset_type = HOT_RESET;
enum pci_ers_result result = PCI_ERS_RESULT_NONE;
const char *location, *pci_str, *drv_str;
@@ -400,10 +432,16 @@ struct pci_dn * handle_eeh_events (struc
/* Walk the various device drivers attached to this slot through
* a reset sequence, giving each an opportunity to do what it needs
- * to accomplish the reset. Each child gets a report of the
- * status ... if any child can't handle the reset, then the entire
- * slot is dlpar removed and added.
+ * to accomplish the reset. Query device driver for special reset
+ * requiements. Report eeh error to each child with cumulative
+ * result status... if any child can't handle the reset,
+ * then the entire slot is dlpar removed and added.
*/
+ pci_walk_bus(frozen_bus, eeh_query_reset_type, &result);
+ if ( result == PCI_ERS_RESULT_FUNDAMENTAL_RESET )
+ reset_type = FUNDAMENTAL_RESET;
+
+ result = PCI_ERS_RESULT_NONE;
pci_walk_bus(frozen_bus, eeh_report_error, &result);
/* Get the current PCI slot state. This can take a long time,
@@ -425,7 +463,8 @@ struct pci_dn * handle_eeh_events (struc
* go down willingly, without panicing the system.
*/
if (result == PCI_ERS_RESULT_NONE) {
- rc = eeh_reset_device(frozen_pdn, frozen_bus);
+ rc = eeh_reset_device(frozen_pdn, frozen_bus, reset_type);
+
if (rc) {
printk(KERN_WARNING "EEH: Unable to reset, rc=%d\n", rc);
goto hard_fail;
@@ -466,7 +505,7 @@ struct pci_dn * handle_eeh_events (struc
/* If any device called out for a reset, then reset the slot */
if (result == PCI_ERS_RESULT_NEED_RESET) {
- rc = eeh_reset_device(frozen_pdn, NULL);
+ rc = eeh_reset_device(frozen_pdn, NULL, reset_type);
if (rc) {
printk(KERN_WARNING "EEH: Cannot reset, rc=%d\n", rc);
goto hard_fail;
--- a/include/linux/pci.h 2009-07-13 14:25:37.000000000 -0700
+++ b/include/linux/pci.h 2009-07-13 16:12:31.000000000 -0700
@@ -446,6 +446,9 @@ enum pci_ers_result {
/* Device driver is fully recovered and operational */
PCI_ERS_RESULT_RECOVERED = (__force pci_ers_result_t) 5,
+
+ /* Device driver requires fundamental reset to recover */
+ PCI_ERS_RESULT_FUNDAMENTAL_RESET = (__force pci_ers_result_t) 6,
};
/* PCI bus error event callbacks */
@@ -465,6 +468,9 @@ struct pci_error_handlers {
/* Device driver may resume normal operations */
void (*resume)(struct pci_dev *dev);
+
+ /* PCI slot requires special reset type for recovery */
+ pci_ers_result_t (*reset_type)(struct pci_dev *dev);
};
/* ---------------------------------------------------------------- */
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