From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [203.10.76.45]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "mx.ozlabs.org", Issuer "CA Cert Signing Authority" (verified OK)) by bilbo.ozlabs.org (Postfix) with ESMTPS id 0AA1CB7257 for ; Thu, 16 Jul 2009 04:32:25 +1000 (EST) Received: from e36.co.us.ibm.com (e36.co.us.ibm.com [32.97.110.154]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e36.co.us.ibm.com", Issuer "Equifax" (verified OK)) by ozlabs.org (Postfix) with ESMTPS id 2D451DDD0B for ; Thu, 16 Jul 2009 04:32:23 +1000 (EST) Received: from d03relay04.boulder.ibm.com (d03relay04.boulder.ibm.com [9.17.195.106]) by e36.co.us.ibm.com (8.13.1/8.13.1) with ESMTP id n6FIUdHt017588 for ; Wed, 15 Jul 2009 12:30:39 -0600 Received: from d03av04.boulder.ibm.com (d03av04.boulder.ibm.com [9.17.195.170]) by d03relay04.boulder.ibm.com (8.13.8/8.13.8/NCO v9.2) with ESMTP id n6FIVuvJ170118 for ; Wed, 15 Jul 2009 12:31:56 -0600 Received: from d03av04.boulder.ibm.com (loopback [127.0.0.1]) by d03av04.boulder.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id n6FIVtkt024129 for ; Wed, 15 Jul 2009 12:31:55 -0600 Message-ID: <4A5E20D1.6040506@us.ibm.com> Date: Wed, 15 Jul 2009 11:32:49 -0700 From: Mike Mason MIME-Version: 1.0 To: linuxppc-dev@ozlabs.org, linux-pci@vger.kernel.org, Paul Mackerras , benh@kernel.crashing.org, linasvepstas@gmail.com Subject: Re: Support for PCI Express reset type in EEH References: <4A5CCFDF.7000901@us.ibm.com> In-Reply-To: <4A5CCFDF.7000901@us.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Cc: Richard Lary List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This patch was simultaneously submitted to Red Hat for review. As a result of that review, I'm withdrawing this patch and will submit a new version shortly. Mike Mike Mason wrote: > 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 > > --- 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); > }; > > /* ---------------------------------------------------------------- */ > >