From 29f8bf1b7f79f689f33e9c4679d182a68b6a5b2c Mon Sep 17 00:00:00 2001 From: Gavin Shan Date: Mon, 27 Feb 2012 20:04:02 +0000 Subject: [PATCH] powerpc/pseries: Cleanup comments in EEH aux components There're several EEH aux components and the patch does some cleanup for them so that they look more clean. * Duplicated comments have been removed from the header file. * Comments have been reorganized so that it looks more clean. * The leading comments of functions are adjusted for a little bit so that the result of "make pdfdocs" would be more unified. * Function calls "xxx ()" has been replaced by "xxx()". Signed-off-by: Gavin Shan Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/eeh_event.h | 34 ++--- arch/powerpc/platforms/pseries/eeh_cache.c | 9 +- arch/powerpc/platforms/pseries/eeh_driver.c | 136 ++++++++++++-------- arch/powerpc/platforms/pseries/eeh_event.c | 23 ++-- arch/powerpc/platforms/pseries/eeh_sysfs.c | 2 +- 5 files changed, 107 insertions(+), 97 deletions(-) diff --git a/arch/powerpc/include/asm/eeh_event.h b/arch/powerpc/include/asm/eeh_event.h index cc3cb04539ac..25ebf6a5aa57 100644 --- a/arch/powerpc/include/asm/eeh_event.h +++ b/arch/powerpc/include/asm/eeh_event.h @@ -1,6 +1,4 @@ /* - * eeh_event.h - * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -22,32 +20,20 @@ #define ASM_POWERPC_EEH_EVENT_H #ifdef __KERNEL__ -/** EEH event -- structure holding pci controller data that describes - * a change in the isolation status of a PCI slot. A pointer - * to this struct is passed as the data pointer in a notify callback. +/* + * structure holding pci controller data that describes a + * change in the isolation status of a PCI slot. A pointer + * to this struct is passed as the data pointer in a notify + * callback. */ struct eeh_event { - struct list_head list; - struct device_node *dn; /* struct device node */ - struct pci_dev *dev; /* affected device */ + struct list_head list; /* to form event queue */ + struct device_node *dn; /* struct device node */ + struct pci_dev *dev; /* affected device */ }; -/** - * eeh_send_failure_event - generate a PCI error event - * @dev pci device - * - * This routine builds a PCI error event which will be delivered - * to all listeners on the eeh_notifier_chain. - * - * This routine can be called within an interrupt context; - * the actual event will be delivered in a normal context - * (from a workqueue). - */ -int eeh_send_failure_event (struct device_node *dn, - struct pci_dev *dev); - -/* Main recovery function */ -struct pci_dn * handle_eeh_events (struct eeh_event *); +int eeh_send_failure_event(struct device_node *dn, struct pci_dev *dev); +struct pci_dn *handle_eeh_events(struct eeh_event *); #endif /* __KERNEL__ */ #endif /* ASM_POWERPC_EEH_EVENT_H */ diff --git a/arch/powerpc/platforms/pseries/eeh_cache.c b/arch/powerpc/platforms/pseries/eeh_cache.c index fc5ae767989e..850c00c166d6 100644 --- a/arch/powerpc/platforms/pseries/eeh_cache.c +++ b/arch/powerpc/platforms/pseries/eeh_cache.c @@ -1,5 +1,4 @@ /* - * eeh_cache.c * PCI address cache; allows the lookup of PCI devices based on I/O address * * Copyright IBM Corporation 2004 @@ -47,8 +46,7 @@ * than any hash algo I could think of for this problem, even * with the penalty of slow pointer chases for d-cache misses). */ -struct pci_io_addr_range -{ +struct pci_io_addr_range { struct rb_node rb_node; unsigned long addr_lo; unsigned long addr_hi; @@ -56,8 +54,7 @@ struct pci_io_addr_range unsigned int flags; }; -static struct pci_io_addr_cache -{ +static struct pci_io_addr_cache { struct rb_root rb_root; spinlock_t piar_lock; } pci_io_addr_cache_root; @@ -166,7 +163,7 @@ pci_addr_cache_insert(struct pci_dev *dev, unsigned long alo, #ifdef DEBUG printk(KERN_DEBUG "PIAR: insert range=[%lx:%lx] dev=%s\n", - alo, ahi, pci_name (dev)); + alo, ahi, pci_name(dev)); #endif rb_link_node(&piar->rb_node, parent, p); diff --git a/arch/powerpc/platforms/pseries/eeh_driver.c b/arch/powerpc/platforms/pseries/eeh_driver.c index 61450e1b3f7d..3f25fab741e2 100644 --- a/arch/powerpc/platforms/pseries/eeh_driver.c +++ b/arch/powerpc/platforms/pseries/eeh_driver.c @@ -33,8 +33,14 @@ #include #include - -static inline const char * pcid_name (struct pci_dev *pdev) +/** + * eeh_pcid_name - Retrieve name of PCI device driver + * @pdev: PCI device + * + * This routine is used to retrieve the name of PCI device driver + * if that's valid. + */ +static inline const char *pcid_name(struct pci_dev *pdev) { if (pdev && pdev->dev.driver) return pdev->dev.driver->name; @@ -64,7 +70,14 @@ static void print_device_node_tree(struct pci_dn *pdn, int dent) #endif /** - * eeh_disable_irq - disable interrupt for the recovering device + * eeh_disable_irq - Disable interrupt for the recovering device + * @dev: PCI device + * + * This routine must be called when reporting temporary or permanent + * error to the particular PCI device to disable interrupt of that + * device. If the device has enabled MSI or MSI-X interrupt, we needn't + * do real work because EEH should freeze DMA transfers for those PCI + * devices encountering EEH errors, which includes MSI or MSI-X. */ static void eeh_disable_irq(struct pci_dev *dev) { @@ -73,7 +86,7 @@ static void eeh_disable_irq(struct pci_dev *dev) /* Don't disable MSI and MSI-X interrupts. They are * effectively disabled by the DMA Stopped state * when an EEH error occurs. - */ + */ if (dev->msi_enabled || dev->msix_enabled) return; @@ -85,7 +98,11 @@ static void eeh_disable_irq(struct pci_dev *dev) } /** - * eeh_enable_irq - enable interrupt for the recovering device + * eeh_enable_irq - Enable interrupt for the recovering device + * @dev: PCI device + * + * This routine must be called to enable interrupt while failed + * device could be resumed. */ static void eeh_enable_irq(struct pci_dev *dev) { @@ -97,15 +114,15 @@ static void eeh_enable_irq(struct pci_dev *dev) } } -/* ------------------------------------------------------- */ /** - * eeh_report_error - report pci error to each device driver + * eeh_report_error - Report pci error to each device driver + * @dev: PCI device + * @userdata: return value * * Report an EEH error to each device driver, collect up and * merge the device driver responses. Cumulative response * passed back in "userdata". */ - static int eeh_report_error(struct pci_dev *dev, void *userdata) { enum pci_ers_result rc, *res = userdata; @@ -122,7 +139,7 @@ static int eeh_report_error(struct pci_dev *dev, void *userdata) !driver->err_handler->error_detected) return 0; - rc = driver->err_handler->error_detected (dev, pci_channel_io_frozen); + rc = driver->err_handler->error_detected(dev, pci_channel_io_frozen); /* A driver that needs a reset trumps all others */ if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; @@ -132,13 +149,14 @@ static int eeh_report_error(struct pci_dev *dev, void *userdata) } /** - * eeh_report_mmio_enabled - tell drivers that MMIO has been enabled + * eeh_report_mmio_enabled - Tell drivers that MMIO has been enabled + * @dev: PCI device + * @userdata: return value * * Tells each device driver that IO ports, MMIO and config space I/O * are now enabled. Collects up and merges the device driver responses. * Cumulative response passed back in "userdata". */ - static int eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata) { enum pci_ers_result rc, *res = userdata; @@ -149,7 +167,7 @@ static int eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata) !driver->err_handler->mmio_enabled) return 0; - rc = driver->err_handler->mmio_enabled (dev); + rc = driver->err_handler->mmio_enabled(dev); /* A driver that needs a reset trumps all others */ if (rc == PCI_ERS_RESULT_NEED_RESET) *res = rc; @@ -159,9 +177,15 @@ static int eeh_report_mmio_enabled(struct pci_dev *dev, void *userdata) } /** - * eeh_report_reset - tell device that slot has been reset + * eeh_report_reset - Tell device that slot has been reset + * @dev: PCI device + * @userdata: return value + * + * This routine must be called while EEH tries to reset particular + * PCI device so that the associated PCI device driver could take + * some actions, usually to save data the driver needs so that the + * driver can work again while the device is recovered. */ - static int eeh_report_reset(struct pci_dev *dev, void *userdata) { enum pci_ers_result rc, *res = userdata; @@ -188,9 +212,14 @@ static int eeh_report_reset(struct pci_dev *dev, void *userdata) } /** - * eeh_report_resume - tell device to resume normal operations + * eeh_report_resume - Tell device to resume normal operations + * @dev: PCI device + * @userdata: return value + * + * This routine must be called to notify the device driver that it + * could resume so that the device driver can do some initialization + * to make the recovered device work again. */ - static int eeh_report_resume(struct pci_dev *dev, void *userdata) { struct pci_driver *driver = dev->driver; @@ -212,12 +241,13 @@ static int eeh_report_resume(struct pci_dev *dev, void *userdata) } /** - * eeh_report_failure - tell device driver that device is dead. + * eeh_report_failure - Tell device driver that device is dead. + * @dev: PCI device + * @userdata: return value * * This informs the device driver that the device is permanently * dead, and that no further recovery attempts will be made on it. */ - static int eeh_report_failure(struct pci_dev *dev, void *userdata) { struct pci_driver *driver = dev->driver; @@ -238,37 +268,16 @@ static int eeh_report_failure(struct pci_dev *dev, void *userdata) return 0; } -/* ------------------------------------------------------- */ /** - * handle_eeh_events -- reset a PCI device after hard lockup. - * - * pSeries systems will isolate a PCI slot if the PCI-Host - * bridge detects address or data parity errors, DMA's - * occurring to wild addresses (which usually happen due to - * bugs in device drivers or in PCI adapter firmware). - * Slot isolations also occur if #SERR, #PERR or other misc - * PCI-related errors are detected. + * eeh_reset_device - Perform actual reset of a pci slot + * @pe_dn: PE associated device node + * @bus: PCI bus corresponding to the isolcated slot * - * Recovery process consists of unplugging the device driver - * (which generated hotplug events to userspace), then issuing - * a PCI #RST to the device, then reconfiguring the PCI config - * space for all bridges & devices under this slot, and then - * finally restarting the device drivers (which cause a second - * set of hotplug events to go out to userspace). + * This routine must be called to do reset on the indicated PE. + * During the reset, udev might be invoked because those affected + * PCI devices will be removed and then added. */ - -/** - * eeh_reset_device() -- perform actual reset of a pci slot - * @bus: pointer to the pci bus structure corresponding - * to the isolated slot. A non-null value will - * cause all devices under the bus to be removed - * and then re-added. - * @pe_dn: pointer to a "Partionable Endpoint" device node. - * This is the top-level structure on which pci - * bus resets can be performed. - */ - -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) { struct device_node *dn; int cnt, rc; @@ -281,12 +290,13 @@ static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus) /* 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. */ + * up if the reset failed for some reason. + */ rc = eeh_reset_pe(pe_dn); if (rc) return rc; - /* Walk over all functions on this device. */ + /* Walk over all functions on this device. */ dn = pe_dn->node; if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent)) dn = dn->parent->child; @@ -308,7 +318,7 @@ static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus) * potentially weird things happen. */ if (bus) { - ssleep (5); + ssleep(5); pcibios_add_pci_devices(bus); } pe_dn->eeh_freeze_count = cnt; @@ -321,7 +331,24 @@ static int eeh_reset_device (struct pci_dn *pe_dn, struct pci_bus *bus) */ #define MAX_WAIT_FOR_RECOVERY 150 -struct pci_dn * handle_eeh_events (struct eeh_event *event) +/** + * eeh_handle_event - Reset a PCI device after hard lockup. + * @event: EEH event + * + * While PHB detects address or data parity errors on particular PCI + * slot, the associated PE will be frozen. Besides, DMA's occurring + * to wild addresses (which usually happen due to bugs in device + * drivers or in PCI adapter firmware) can cause EEH error. #SERR, + * #PERR or other misc PCI-related errors also can trigger EEH errors. + * + * Recovery process consists of unplugging the device driver (which + * generated hotplug events to userspace), then issuing a PCI #RST to + * the device, then reconfiguring the PCI config space for all bridges + * & devices under this slot, and then finally restarting the device + * drivers (which cause a second set of hotplug events to go out to + * userspace). + */ +struct pci_dn *handle_eeh_events(struct eeh_event *event) { struct device_node *frozen_dn; struct pci_dn *frozen_pdn; @@ -350,9 +377,10 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event) * which was always an EADS pci bridge. In the new style, * there might not be any EADS bridges, and even when there are, * the firmware marks them as "EEH incapable". So another - * two-step is needed to find the pci bus.. */ + * two-step is needed to find the pci bus.. + */ if (!frozen_bus) - frozen_bus = pcibios_find_pci_bus (frozen_dn->parent); + frozen_bus = pcibios_find_pci_bus(frozen_dn->parent); if (!frozen_bus) { printk(KERN_ERR "EEH: Cannot find PCI bus " @@ -395,7 +423,8 @@ struct pci_dn * handle_eeh_events (struct eeh_event *event) pci_walk_bus(frozen_bus, eeh_report_error, &result); /* Get the current PCI slot state. This can take a long time, - * sometimes over 3 seconds for certain systems. */ + * sometimes over 3 seconds for certain systems. + */ rc = eeh_ops->wait_state(frozen_pdn->node, MAX_WAIT_FOR_RECOVERY*1000); if (rc < 0 || rc == EEH_STATE_NOT_SUPPORT) { printk(KERN_WARNING "EEH: Permanent failure\n"); @@ -508,4 +537,3 @@ perm_error: return NULL; } -/* ---------- end of file ---------- */ diff --git a/arch/powerpc/platforms/pseries/eeh_event.c b/arch/powerpc/platforms/pseries/eeh_event.c index d2383cfb6dfd..e98347cb9cc0 100644 --- a/arch/powerpc/platforms/pseries/eeh_event.c +++ b/arch/powerpc/platforms/pseries/eeh_event.c @@ -1,6 +1,4 @@ /* - * eeh_event.c - * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or @@ -46,7 +44,7 @@ DECLARE_WORK(eeh_event_wq, eeh_thread_launcher); DEFINE_MUTEX(eeh_event_mutex); /** - * eeh_event_handler - dispatch EEH events. + * eeh_event_handler - Dispatch EEH events. * @dummy - unused * * The detection of a frozen slot can occur inside an interrupt, @@ -61,7 +59,7 @@ static int eeh_event_handler(void * dummy) struct eeh_event *event; struct pci_dn *pdn; - daemonize ("eehd"); + daemonize("eehd"); set_current_state(TASK_INTERRUPTIBLE); spin_lock_irqsave(&eeh_eventlist_lock, flags); @@ -93,7 +91,7 @@ static int eeh_event_handler(void * dummy) /* If there are no new errors after an hour, clear the counter. */ if (pdn && pdn->eeh_freeze_count>0) { - msleep_interruptible (3600*1000); + msleep_interruptible(3600*1000); if (pdn->eeh_freeze_count>0) pdn->eeh_freeze_count--; } @@ -102,8 +100,11 @@ static int eeh_event_handler(void * dummy) } /** - * eeh_thread_launcher + * eeh_thread_launcher - Start kernel thread to handle EEH events * @dummy - unused + * + * This routine is called to start the kernel thread for processing + * EEH event. */ static void eeh_thread_launcher(struct work_struct *dummy) { @@ -112,14 +113,14 @@ static void eeh_thread_launcher(struct work_struct *dummy) } /** - * eeh_send_failure_event - generate a PCI error event - * @dev pci device + * eeh_send_failure_event - Generate a PCI error event + * @dev: pci device * * This routine can be called within an interrupt context; * the actual event will be delivered in a normal context * (from a workqueue). */ -int eeh_send_failure_event (struct device_node *dn, +int eeh_send_failure_event(struct device_node *dn, struct pci_dev *dev) { unsigned long flags; @@ -135,7 +136,7 @@ int eeh_send_failure_event (struct device_node *dn, } event = kmalloc(sizeof(*event), GFP_ATOMIC); if (event == NULL) { - printk (KERN_ERR "EEH: out of memory, event not handled\n"); + printk(KERN_ERR "EEH: out of memory, event not handled\n"); return 1; } @@ -154,5 +155,3 @@ int eeh_send_failure_event (struct device_node *dn, return 0; } - -/********************** END OF FILE ******************************/ diff --git a/arch/powerpc/platforms/pseries/eeh_sysfs.c b/arch/powerpc/platforms/pseries/eeh_sysfs.c index eb744ee234da..5e4eab1f4441 100644 --- a/arch/powerpc/platforms/pseries/eeh_sysfs.c +++ b/arch/powerpc/platforms/pseries/eeh_sysfs.c @@ -28,7 +28,7 @@ #include /** - * EEH_SHOW_ATTR -- create sysfs entry for eeh statistic + * EEH_SHOW_ATTR -- Create sysfs entry for eeh statistic * @_name: name of file in sysfs directory * @_memb: name of member in struct pci_dn to access * @_format: printf format for display -- 2.20.1