To support asynchronous NMI-like notifications on arm64 we need to use the estatus-queue. These patches refactor it to allow multiple APEI notification types to use it.
First we move the estatus-queue code higher in the file so that any notify_foo() handler can make use of it. This patch moves code around ... and makes the following trivial change: Rewrite the dated comment above ghes_estatus_llist. printk() is no longer the issue, its the helpers like memory_failure_queue() that still aren't nmi safe. Signed-off-by: James Morse <[email protected]> Reviewed-by: Punit Agrawal <[email protected]> --- Changes since v1: * Comments and typos, drivers/acpi/apei/ghes.c | 265 ++++++++++++++++++++++++----------------------- 1 file changed, 137 insertions(+), 128 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index 1efefe919555..e2af91c92135 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -545,6 +545,16 @@ static int ghes_print_estatus(const char *pfx, return 0; } +static void __ghes_panic(struct ghes *ghes) +{ + __ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus); + + /* reboot to log the error! */ + if (!panic_timeout) + panic_timeout = ghes_panic_timeout; + panic("Fatal hardware error!"); +} + /* * GHES error status reporting throttle, to report more kinds of * errors, instead of just most frequently occurred errors. @@ -672,6 +682,133 @@ static void ghes_estatus_cache_add( rcu_read_unlock(); } +#ifdef CONFIG_HAVE_ACPI_APEI_NMI +/* + * Handlers for CPER records may not be NMI safe. For example, + * memory_failure_queue() takes spinlocks and calls schedule_work_on(). + * In any NMI-like handler, memory from ghes_estatus_pool is used to save + * estatus, and added to the ghes_estatus_llist. irq_work_queue() causes + * ghes_proc_in_irq() to run in IRQ context where each estatus in + * ghes_estatus_llist is processed. Each NMI-like error source must grow + * the ghes_estatus_pool to ensure memory is available. + * + * Memory from the ghes_estatus_pool is also used with the ghes_estatus_cache + * to suppress frequent messages. + */ +static struct llist_head ghes_estatus_llist; +static struct irq_work ghes_proc_irq_work; + +static void ghes_print_queued_estatus(void) +{ + struct llist_node *llnode; + struct ghes_estatus_node *estatus_node; + struct acpi_hest_generic *generic; + struct acpi_hest_generic_status *estatus; + + llnode = llist_del_all(&ghes_estatus_llist); + /* + * Because the time order of estatus in list is reversed, + * revert it back to proper order. + */ + llnode = llist_reverse_order(llnode); + while (llnode) { + estatus_node = llist_entry(llnode, struct ghes_estatus_node, + llnode); + estatus = GHES_ESTATUS_FROM_NODE(estatus_node); + generic = estatus_node->generic; + ghes_print_estatus(NULL, generic, estatus); + llnode = llnode->next; + } +} + +/* Save estatus for further processing in IRQ context */ +static void __process_error(struct ghes *ghes) +{ +#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG + u32 len, node_len; + struct ghes_estatus_node *estatus_node; + struct acpi_hest_generic_status *estatus; + + if (ghes_estatus_cached(ghes->estatus)) + return; + + len = cper_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) + return; + + estatus_node->ghes = ghes; + 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 +} + +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 void ghes_estatus_pool_shrink(unsigned long len) +{ + ghes_estatus_pool_size_request -= PAGE_ALIGN(len); +} + +static void ghes_proc_in_irq(struct irq_work *irq_work) +{ + struct llist_node *llnode, *next; + struct ghes_estatus_node *estatus_node; + struct acpi_hest_generic *generic; + struct acpi_hest_generic_status *estatus; + u32 len, node_len; + + llnode = llist_del_all(&ghes_estatus_llist); + /* + * Because the time order of estatus in list is reversed, + * revert it back to proper order. + */ + llnode = llist_reverse_order(llnode); + while (llnode) { + next = llnode->next; + estatus_node = llist_entry(llnode, struct ghes_estatus_node, + llnode); + estatus = GHES_ESTATUS_FROM_NODE(estatus_node); + len = cper_estatus_len(estatus); + node_len = GHES_ESTATUS_NODE_LEN(len); + ghes_do_proc(estatus_node->ghes, estatus); + if (!ghes_estatus_cached(estatus)) { + generic = estatus_node->generic; + if (ghes_print_estatus(NULL, generic, estatus)) + ghes_estatus_cache_add(generic, estatus); + } + gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, + node_len); + llnode = next; + } +} + +static void ghes_nmi_init_cxt(void) +{ + init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq); +} + +#else +static inline void ghes_nmi_init_cxt(void) { } +#endif /* CONFIG_HAVE_ACPI_APEI_NMI */ + static int ghes_ack_error(struct acpi_hest_generic_v2 *gv2) { int rc; @@ -687,16 +824,6 @@ static int ghes_ack_error(struct acpi_hest_generic_v2 *gv2) return apei_write(val, &gv2->read_ack_register); } -static void __ghes_panic(struct ghes *ghes) -{ - __ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus); - - /* reboot to log the error! */ - if (!panic_timeout) - panic_timeout = ghes_panic_timeout; - panic("Fatal hardware error!"); -} - static int ghes_proc(struct ghes *ghes) { int rc; @@ -828,17 +955,6 @@ static inline void ghes_sea_remove(struct ghes *ghes) { } #endif /* CONFIG_ACPI_APEI_SEA */ #ifdef CONFIG_HAVE_ACPI_APEI_NMI -/* - * 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 llist_head ghes_estatus_llist; -static struct irq_work ghes_proc_irq_work; - /* * NMI may be triggered on any CPU, so ghes_in_nmi is used for * having only one concurrent reader. @@ -847,88 +963,6 @@ static atomic_t ghes_in_nmi = ATOMIC_INIT(0); static LIST_HEAD(ghes_nmi); -static void ghes_proc_in_irq(struct irq_work *irq_work) -{ - struct llist_node *llnode, *next; - struct ghes_estatus_node *estatus_node; - struct acpi_hest_generic *generic; - struct acpi_hest_generic_status *estatus; - u32 len, node_len; - - llnode = llist_del_all(&ghes_estatus_llist); - /* - * Because the time order of estatus in list is reversed, - * revert it back to proper order. - */ - llnode = llist_reverse_order(llnode); - while (llnode) { - next = llnode->next; - estatus_node = llist_entry(llnode, struct ghes_estatus_node, - llnode); - estatus = GHES_ESTATUS_FROM_NODE(estatus_node); - len = cper_estatus_len(estatus); - node_len = GHES_ESTATUS_NODE_LEN(len); - ghes_do_proc(estatus_node->ghes, estatus); - if (!ghes_estatus_cached(estatus)) { - generic = estatus_node->generic; - if (ghes_print_estatus(NULL, generic, estatus)) - ghes_estatus_cache_add(generic, estatus); - } - gen_pool_free(ghes_estatus_pool, (unsigned long)estatus_node, - node_len); - llnode = next; - } -} - -static void ghes_print_queued_estatus(void) -{ - struct llist_node *llnode; - struct ghes_estatus_node *estatus_node; - struct acpi_hest_generic *generic; - struct acpi_hest_generic_status *estatus; - - llnode = llist_del_all(&ghes_estatus_llist); - /* - * Because the time order of estatus in list is reversed, - * revert it back to proper order. - */ - llnode = llist_reverse_order(llnode); - while (llnode) { - estatus_node = llist_entry(llnode, struct ghes_estatus_node, - llnode); - estatus = GHES_ESTATUS_FROM_NODE(estatus_node); - generic = estatus_node->generic; - ghes_print_estatus(NULL, generic, estatus); - llnode = llnode->next; - } -} - -/* Save estatus for further processing in IRQ context */ -static void __process_error(struct ghes *ghes) -{ -#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - u32 len, node_len; - struct ghes_estatus_node *estatus_node; - struct acpi_hest_generic_status *estatus; - - if (ghes_estatus_cached(ghes->estatus)) - return; - - len = cper_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) - return; - - estatus_node->ghes = ghes; - 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 -} - static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) { struct ghes *ghes; @@ -967,26 +1001,6 @@ static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) return ret; } -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 void ghes_estatus_pool_shrink(unsigned long len) -{ - ghes_estatus_pool_size_request -= PAGE_ALIGN(len); -} - static void ghes_nmi_add(struct ghes *ghes) { unsigned long len; @@ -1018,14 +1032,9 @@ static void ghes_nmi_remove(struct ghes *ghes) ghes_estatus_pool_shrink(len); } -static void ghes_nmi_init_cxt(void) -{ - init_irq_work(&ghes_proc_irq_work, ghes_proc_in_irq); -} #else /* CONFIG_HAVE_ACPI_APEI_NMI */ static inline void ghes_nmi_add(struct ghes *ghes) { } static inline void ghes_nmi_remove(struct ghes *ghes) { } -static inline void ghes_nmi_init_cxt(void) { } #endif /* CONFIG_HAVE_ACPI_APEI_NMI */ static int ghes_probe(struct platform_device *ghes_dev) -- 2.16.2 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
