From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757291Ab1DGB3i (ORCPT ); Wed, 6 Apr 2011 21:29:38 -0400 Received: from mga01.intel.com ([192.55.52.88]:40761 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757265Ab1DGB3Z (ORCPT ); Wed, 6 Apr 2011 21:29:25 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.63,313,1299484800"; d="scan'208";a="676182860" From: Huang Ying To: Len Brown Cc: linux-kernel@vger.kernel.org, Andi Kleen , Tony Luck , ying.huang@intel.com, linux-acpi@vger.kernel.org Subject: [PATCH -v2 4/4] ACPI, APEI, GHES, printk support for recoverable error via NMI Date: Thu, 7 Apr 2011 09:29:06 +0800 Message-Id: <1302139746-1030-5-git-send-email-ying.huang@intel.com> X-Mailer: git-send-email 1.7.4.1 In-Reply-To: <1302139746-1030-1-git-send-email-ying.huang@intel.com> References: <1302139746-1030-1-git-send-email-ying.huang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Some APEI GHES recoverable errors are reported via NMI, but printk is not safe in NMI context. To solve the issue, a lock-less memory allocator is used to allocate memory in NMI handler, save the error record into the allocated memory, put the error record into a lock-less list. On the other hand, a irq_work is used to delay the operation from NMI context to IRQ context. The irq_work IRQ handler will remove nodes from lock-less list, printk the error record and do some further processing include recovery operation, then free the memory. Signed-off-by: Huang Ying --- drivers/acpi/apei/Kconfig | 2 drivers/acpi/apei/ghes.c | 186 ++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 175 insertions(+), 13 deletions(-) --- a/drivers/acpi/apei/Kconfig +++ b/drivers/acpi/apei/Kconfig @@ -12,6 +12,8 @@ config ACPI_APEI_GHES tristate "APEI Generic Hardware Error Source" depends on ACPI_APEI && X86 select ACPI_HED + select LLIST + select GENERIC_ALLOCATOR help Generic Hardware Error Source provides a way to report platform hardware errors (such as that from chipset). It --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -42,6 +42,9 @@ #include #include #include +#include +#include +#include #include #include #include @@ -53,6 +56,15 @@ #define GHES_PFX "GHES: " #define GHES_ESTATUS_MAX_SIZE 65536 +#define GHES_ESOURCE_PREALLOC_MAX_SIZE 65536 + +#define GHES_ESTATUS_POOL_MIN_ALLOC_ORDER 3 + +#define GHES_ESTATUS_NODE_LEN(estatus_len) \ + (sizeof(struct ghes_estatus_node) + (estatus_len)) +#define GHES_ESTATUS_FROM_NODE(estatus_node) \ + ((struct acpi_hest_generic_status *) \ + ((struct ghes_estatus_node *)(estatus_node) + 1)) /* * One struct ghes is created for each generic hardware error source. @@ -77,6 +89,11 @@ struct ghes { }; }; +struct ghes_estatus_node { + struct llist_node llnode; + struct acpi_hest_generic *generic; +}; + static int ghes_panic_timeout __read_mostly = 30; /* @@ -121,6 +138,19 @@ static struct vm_struct *ghes_ioremap_ar static DEFINE_RAW_SPINLOCK(ghes_ioremap_lock_nmi); static DEFINE_SPINLOCK(ghes_ioremap_lock_irq); +/* + * printk is not safe in NMI context. So in NMI handler, we allocate + * required memory from lock-less memory allocator + * (ghes_estatus_pool), save estatus into it, put them into lock-less + * list (ghes_estatus_llist), then delay printk into IRQ context via + * irq_work (ghes_proc_irq_work). ghes_estatus_size_request record + * required pool size by all NMI error source. + */ +static struct gen_pool *ghes_estatus_pool; +static unsigned long ghes_estatus_pool_size_request; +static struct llist_head ghes_estatus_llist; +static struct irq_work ghes_proc_irq_work; + static int ghes_ioremap_init(void) { ghes_ioremap_area = __get_vm_area(PAGE_SIZE * GHES_IOREMAP_PAGES, @@ -180,6 +210,50 @@ static void ghes_iounmap_irq(void __iome __flush_tlb_one(vaddr); } +static int ghes_estatus_pool_init(void) +{ + ghes_estatus_pool = gen_pool_create(GHES_ESTATUS_POOL_MIN_ALLOC_ORDER, -1); + if (!ghes_estatus_pool) + return -ENOMEM; + return 0; +} + +static void ghes_estatus_pool_exit(void) +{ + struct gen_pool_chunk *chunk; + + gen_pool_for_each_chunk(chunk, ghes_estatus_pool) + free_page(chunk->start_addr); + gen_pool_destroy(ghes_estatus_pool); +} + +static int ghes_estatus_pool_expand(unsigned long len) +{ + unsigned long i, pages, size, addr; + int ret; + + ghes_estatus_pool_size_request += PAGE_ALIGN(len); + size = gen_pool_size(ghes_estatus_pool); + if (size >= ghes_estatus_pool_size_request) + return 0; + pages = (ghes_estatus_pool_size_request - size) / PAGE_SIZE; + for (i = 0; i < pages; i++) { + addr = __get_free_page(GFP_KERNEL); + if (!addr) + return -ENOMEM; + ret = gen_pool_add(ghes_estatus_pool, addr, PAGE_SIZE, -1); + if (ret) + return ret; + } + + return 0; +} + +static void ghes_estatus_pool_shrink(unsigned long len) +{ + ghes_estatus_pool_size_request -= PAGE_ALIGN(len); +} + static struct ghes *ghes_new(struct acpi_hest_generic *generic) { struct ghes *ghes; @@ -341,13 +415,13 @@ static void ghes_clear_estatus(struct gh ghes->flags &= ~GHES_TO_CLEAR; } -static void ghes_do_proc(struct ghes *ghes) +static void ghes_do_proc(const struct acpi_hest_generic_status *estatus) { int sev, processed = 0; struct acpi_hest_generic_data *gdata; - sev = ghes_severity(ghes->estatus->error_severity); - apei_estatus_for_each_section(ghes->estatus, gdata) { + sev = ghes_severity(estatus->error_severity); + apei_estatus_for_each_section(estatus, gdata) { #ifdef CONFIG_X86_MCE if (!uuid_le_cmp(*(uuid_le *)gdata->section_type, CPER_SEC_PLATFORM_MEM)) { @@ -360,13 +434,15 @@ static void ghes_do_proc(struct ghes *gh } } -static void ghes_print_estatus(const char *pfx, struct ghes *ghes) +static void ghes_print_estatus(const char *pfx, + const struct acpi_hest_generic *generic, + const struct acpi_hest_generic_status *estatus) { /* Not more than 2 messages every 5 seconds */ static DEFINE_RATELIMIT_STATE(ratelimit, 5*HZ, 2); if (pfx == NULL) { - if (ghes_severity(ghes->estatus->error_severity) <= + if (ghes_severity(estatus->error_severity) <= GHES_SEV_CORRECTED) pfx = KERN_WARNING HW_ERR; else @@ -375,8 +451,8 @@ static void ghes_print_estatus(const cha if (__ratelimit(&ratelimit)) { printk( "%s""Hardware error from APEI Generic Hardware Error Source: %d\n", - pfx, ghes->generic->header.source_id); - apei_estatus_print(pfx, ghes->estatus); + pfx, generic->header.source_id); + apei_estatus_print(pfx, estatus); } } @@ -387,8 +463,8 @@ static int ghes_proc(struct ghes *ghes) rc = ghes_read_estatus(ghes, 0); if (rc) goto out; - ghes_print_estatus(NULL, ghes); - ghes_do_proc(ghes); + ghes_print_estatus(NULL, ghes->generic, ghes->estatus); + ghes_do_proc(ghes->estatus); out: ghes_clear_estatus(ghes); @@ -447,6 +523,40 @@ static int ghes_notify_sci(struct notifi return ret; } +static void ghes_proc_in_irq(struct irq_work *irq_work) +{ + struct llist_node *llnode, *next, *tail = NULL; + struct ghes_estatus_node *estatus_node; + struct acpi_hest_generic_status *estatus; + u32 len, node_len; + + /* + * Because the time order of estatus in list is reversed, + * revert it back to proper order. + */ + llnode = llist_del_all(&ghes_estatus_llist); + while (llnode) { + next = llnode->next; + llnode->next = tail; + tail = llnode; + llnode = next; + } + llnode = tail; + while (llnode) { + next = llnode->next; + estatus_node = llist_entry(llnode, struct ghes_estatus_node, + llnode); + estatus = GHES_ESTATUS_FROM_NODE(estatus_node); + len = apei_estatus_len(estatus); + node_len = GHES_ESTATUS_NODE_LEN(len); + ghes_do_proc(estatus); + ghes_print_estatus(NULL, estatus_node->generic, estatus); + gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, + node_len); + llnode = next; + } +} + static int ghes_notify_nmi(struct notifier_block *this, unsigned long cmd, void *data) { @@ -476,7 +586,8 @@ static int ghes_notify_nmi(struct notifi if (sev_global >= GHES_SEV_PANIC) { oops_begin(); - ghes_print_estatus(KERN_EMERG HW_ERR, ghes_global); + ghes_print_estatus(KERN_EMERG HW_ERR, ghes_global->generic, + ghes_global->estatus); /* reboot to log the error! */ if (panic_timeout == 0) panic_timeout = ghes_panic_timeout; @@ -484,12 +595,31 @@ static int ghes_notify_nmi(struct notifi } list_for_each_entry_rcu(ghes, &ghes_nmi, list) { +#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + u32 len, node_len; + struct ghes_estatus_node *estatus_node; + struct acpi_hest_generic_status *estatus; +#endif if (!(ghes->flags & GHES_TO_CLEAR)) continue; - /* Do not print estatus because printk is not NMI safe */ - ghes_do_proc(ghes); +#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + /* Save estatus for further processing in IRQ context */ + len = apei_estatus_len(ghes->estatus); + node_len = GHES_ESTATUS_NODE_LEN(len); + estatus_node = (void *)gen_pool_alloc(ghes_estatus_pool, + node_len); + if (estatus_node) { + estatus_node->generic = ghes->generic; + estatus = GHES_ESTATUS_FROM_NODE(estatus_node); + memcpy(estatus, ghes->estatus, len); + llist_add(&estatus_node->llnode, &ghes_estatus_llist); + } +#endif ghes_clear_estatus(ghes); } +#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + irq_work_queue(&ghes_proc_irq_work); +#endif out: raw_spin_unlock(&ghes_nmi_lock); @@ -504,10 +634,26 @@ static struct notifier_block ghes_notifi .notifier_call = ghes_notify_nmi, }; +static unsigned long ghes_esource_prealloc_size( + const struct acpi_hest_generic *generic) +{ + unsigned long block_length, prealloc_records, prealloc_size; + + block_length = min_t(unsigned long, generic->error_block_length, + GHES_ESTATUS_MAX_SIZE); + prealloc_records = max_t(unsigned long, + generic->records_to_preallocate, 1); + prealloc_size = min_t(unsigned long, block_length * prealloc_records, + GHES_ESOURCE_PREALLOC_MAX_SIZE); + + return prealloc_size; +} + static int __devinit ghes_probe(struct platform_device *ghes_dev) { struct acpi_hest_generic *generic; struct ghes *ghes = NULL; + unsigned long len; int rc = -EINVAL; generic = *(struct acpi_hest_generic **)ghes_dev->dev.platform_data; @@ -573,6 +719,8 @@ static int __devinit ghes_probe(struct p mutex_unlock(&ghes_list_mutex); break; case ACPI_HEST_NOTIFY_NMI: + len = ghes_esource_prealloc_size(generic); + ghes_estatus_pool_expand(len); mutex_lock(&ghes_list_mutex); if (list_empty(&ghes_nmi)) register_die_notifier(&ghes_notifier_nmi); @@ -597,6 +745,7 @@ static int __devexit ghes_remove(struct { struct ghes *ghes; struct acpi_hest_generic *generic; + unsigned long len; ghes = platform_get_drvdata(ghes_dev); generic = ghes->generic; @@ -627,6 +776,8 @@ static int __devexit ghes_remove(struct * freed after NMI handler finishes. */ synchronize_rcu(); + len = ghes_esource_prealloc_size(generic); + ghes_estatus_pool_shrink(len); break; default: BUG(); @@ -662,15 +813,23 @@ static int __init ghes_init(void) return -EINVAL; } + init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq); + rc = ghes_ioremap_init(); if (rc) goto err; - rc = platform_driver_register(&ghes_platform_driver); + rc = ghes_estatus_pool_init(); if (rc) goto err_ioremap_exit; + rc = platform_driver_register(&ghes_platform_driver); + if (rc) + goto err_pool_exit; + return 0; +err_pool_exit: + ghes_estatus_pool_exit(); err_ioremap_exit: ghes_ioremap_exit(); err: @@ -680,6 +839,7 @@ err: static void __exit ghes_exit(void) { platform_driver_unregister(&ghes_platform_driver); + ghes_estatus_pool_exit(); ghes_ioremap_exit(); }