From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Morse Subject: [PATCH v3 02/12] ACPI / APEI: Generalise the estatus queue's add/remove and notify code Date: Fri, 27 Apr 2018 16:35:00 +0100 Message-ID: <20180427153510.5799-3-james.morse@arm.com> References: <20180427153510.5799-1-james.morse@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180427153510.5799-1-james.morse@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: linux-acpi@vger.kernel.org Cc: jonathan.zhang@cavium.com, Rafael Wysocki , Tony Luck , Christoffer Dall , Punit Agrawal , Xie XiuQi , Marc Zyngier , Catalin Marinas , Tyler Baicar , Will Deacon , Dongjiu Geng , linux-mm@kvack.org, Borislav Petkov , James Morse , Naoya Horiguchi , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, Len Brown List-Id: linux-acpi@vger.kernel.org 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. Refactor the estatus queue's pool grow/shrink code and notification routine from NOTIFY_NMI's handlers. This will allow another notification method to use the estatus queue without duplicating this code. This patch adds rcu_read_lock()/rcu_read_unlock() around the list list_for_each_entry_rcu() walker. These aren't strictly necessary as the whole nmi_enter/nmi_exit() window is a spooky RCU read-side critical section. Keep the oops_begin() call for x86, arm64 doesn't have one of these, and APEI is the only thing outside arch code calling this.. The existing ghes_estatus_pool_shrink() is folded into the new ghes_estatus_queue_shrink_pool() as only the queue uses it. _in_nmi_notify_one() is separate from the rcu-list walker for a later caller that doesn't need to walk a list. Signed-off-by: James Morse Reviewed-by: Punit Agrawal --- Changes since v1: * Tidied up _in_nmi_notify_one(). drivers/acpi/apei/ghes.c | 100 ++++++++++++++++++++++++++++++----------------- 1 file changed, 65 insertions(+), 35 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index e2af91c92135..c8a6c5b0516e 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -747,6 +747,51 @@ static void __process_error(struct ghes *ghes) #endif } +static int _in_nmi_notify_one(struct ghes *ghes) +{ + int sev; + + if (ghes_read_estatus(ghes, 1)) { + ghes_clear_estatus(ghes); + return -ENOENT; + } + + sev = ghes_severity(ghes->estatus->error_severity); + if (sev >= GHES_SEV_PANIC) { +#ifdef CONFIG_X86 + oops_begin(); +#endif + ghes_print_queued_estatus(); + __ghes_panic(ghes); + } + + if (!(ghes->flags & GHES_TO_CLEAR)) + return 0; + + __process_error(ghes); + ghes_clear_estatus(ghes); + + return 0; +} + +static int ghes_estatus_queue_notified(struct list_head *rcu_list) +{ + int ret = -ENOENT; + struct ghes *ghes; + + rcu_read_lock(); + list_for_each_entry_rcu(ghes, rcu_list, list) { + if (!_in_nmi_notify_one(ghes)) + ret = 0; + } + rcu_read_unlock(); + + if (IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && ret == 0) + irq_work_queue(&ghes_proc_irq_work); + + return ret; +} + static unsigned long ghes_esource_prealloc_size( const struct acpi_hest_generic *generic) { @@ -762,11 +807,24 @@ static unsigned long ghes_esource_prealloc_size( return prealloc_size; } -static void ghes_estatus_pool_shrink(unsigned long len) +/* After removing a queue user, we can shrink the pool */ +static void ghes_estatus_queue_shrink_pool(struct ghes *ghes) { + unsigned long len; + + len = ghes_esource_prealloc_size(ghes->generic); ghes_estatus_pool_size_request -= PAGE_ALIGN(len); } +/* Before adding a queue user, grow the pool */ +static void ghes_estatus_queue_grow_pool(struct ghes *ghes) +{ + unsigned long len; + + len = ghes_esource_prealloc_size(ghes->generic); + ghes_estatus_pool_expand(len); +} + static void ghes_proc_in_irq(struct irq_work *irq_work) { struct llist_node *llnode, *next; @@ -965,48 +1023,22 @@ static LIST_HEAD(ghes_nmi); static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) { - struct ghes *ghes; - int sev, ret = NMI_DONE; + int ret = NMI_DONE; if (!atomic_add_unless(&ghes_in_nmi, 1, 1)) return ret; - list_for_each_entry_rcu(ghes, &ghes_nmi, list) { - if (ghes_read_estatus(ghes, 1)) { - ghes_clear_estatus(ghes); - continue; - } else { - ret = NMI_HANDLED; - } - - sev = ghes_severity(ghes->estatus->error_severity); - if (sev >= GHES_SEV_PANIC) { - oops_begin(); - ghes_print_queued_estatus(); - __ghes_panic(ghes); - } + if (!ghes_estatus_queue_notified(&ghes_nmi)) + ret = NMI_HANDLED; - if (!(ghes->flags & GHES_TO_CLEAR)) - continue; - - __process_error(ghes); - ghes_clear_estatus(ghes); - } - -#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - if (ret == NMI_HANDLED) - irq_work_queue(&ghes_proc_irq_work); -#endif atomic_dec(&ghes_in_nmi); return ret; } static void ghes_nmi_add(struct ghes *ghes) { - unsigned long len; + ghes_estatus_queue_grow_pool(ghes); - len = ghes_esource_prealloc_size(ghes->generic); - ghes_estatus_pool_expand(len); mutex_lock(&ghes_list_mutex); if (list_empty(&ghes_nmi)) register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes"); @@ -1016,8 +1048,6 @@ static void ghes_nmi_add(struct ghes *ghes) static void ghes_nmi_remove(struct ghes *ghes) { - unsigned long len; - mutex_lock(&ghes_list_mutex); list_del_rcu(&ghes->list); if (list_empty(&ghes_nmi)) @@ -1028,8 +1058,8 @@ static void ghes_nmi_remove(struct ghes *ghes) * freed after NMI handler finishes. */ synchronize_rcu(); - len = ghes_esource_prealloc_size(ghes->generic); - ghes_estatus_pool_shrink(len); + + ghes_estatus_queue_shrink_pool(ghes); } #else /* CONFIG_HAVE_ACPI_APEI_NMI */ -- 2.16.2 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f71.google.com (mail-oi0-f71.google.com [209.85.218.71]) by kanga.kvack.org (Postfix) with ESMTP id 740C66B0007 for ; Fri, 27 Apr 2018 11:38:27 -0400 (EDT) Received: by mail-oi0-f71.google.com with SMTP id 5-v6so1222733oiq.6 for ; Fri, 27 Apr 2018 08:38:27 -0700 (PDT) Received: from foss.arm.com (foss.arm.com. [217.140.101.70]) by mx.google.com with ESMTP id p63-v6si550046oie.49.2018.04.27.08.38.26 for ; Fri, 27 Apr 2018 08:38:26 -0700 (PDT) From: James Morse Subject: [PATCH v3 02/12] ACPI / APEI: Generalise the estatus queue's add/remove and notify code Date: Fri, 27 Apr 2018 16:35:00 +0100 Message-Id: <20180427153510.5799-3-james.morse@arm.com> In-Reply-To: <20180427153510.5799-1-james.morse@arm.com> References: <20180427153510.5799-1-james.morse@arm.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-acpi@vger.kernel.org Cc: kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org, linux-mm@kvack.org, Borislav Petkov , Marc Zyngier , Christoffer Dall , Will Deacon , Catalin Marinas , Naoya Horiguchi , Rafael Wysocki , Len Brown , Tony Luck , Tyler Baicar , Dongjiu Geng , Xie XiuQi , Punit Agrawal , jonathan.zhang@cavium.com, James Morse 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. Refactor the estatus queue's pool grow/shrink code and notification routine from NOTIFY_NMI's handlers. This will allow another notification method to use the estatus queue without duplicating this code. This patch adds rcu_read_lock()/rcu_read_unlock() around the list list_for_each_entry_rcu() walker. These aren't strictly necessary as the whole nmi_enter/nmi_exit() window is a spooky RCU read-side critical section. Keep the oops_begin() call for x86, arm64 doesn't have one of these, and APEI is the only thing outside arch code calling this.. The existing ghes_estatus_pool_shrink() is folded into the new ghes_estatus_queue_shrink_pool() as only the queue uses it. _in_nmi_notify_one() is separate from the rcu-list walker for a later caller that doesn't need to walk a list. Signed-off-by: James Morse Reviewed-by: Punit Agrawal --- Changes since v1: * Tidied up _in_nmi_notify_one(). drivers/acpi/apei/ghes.c | 100 ++++++++++++++++++++++++++++++----------------- 1 file changed, 65 insertions(+), 35 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index e2af91c92135..c8a6c5b0516e 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -747,6 +747,51 @@ static void __process_error(struct ghes *ghes) #endif } +static int _in_nmi_notify_one(struct ghes *ghes) +{ + int sev; + + if (ghes_read_estatus(ghes, 1)) { + ghes_clear_estatus(ghes); + return -ENOENT; + } + + sev = ghes_severity(ghes->estatus->error_severity); + if (sev >= GHES_SEV_PANIC) { +#ifdef CONFIG_X86 + oops_begin(); +#endif + ghes_print_queued_estatus(); + __ghes_panic(ghes); + } + + if (!(ghes->flags & GHES_TO_CLEAR)) + return 0; + + __process_error(ghes); + ghes_clear_estatus(ghes); + + return 0; +} + +static int ghes_estatus_queue_notified(struct list_head *rcu_list) +{ + int ret = -ENOENT; + struct ghes *ghes; + + rcu_read_lock(); + list_for_each_entry_rcu(ghes, rcu_list, list) { + if (!_in_nmi_notify_one(ghes)) + ret = 0; + } + rcu_read_unlock(); + + if (IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && ret == 0) + irq_work_queue(&ghes_proc_irq_work); + + return ret; +} + static unsigned long ghes_esource_prealloc_size( const struct acpi_hest_generic *generic) { @@ -762,11 +807,24 @@ static unsigned long ghes_esource_prealloc_size( return prealloc_size; } -static void ghes_estatus_pool_shrink(unsigned long len) +/* After removing a queue user, we can shrink the pool */ +static void ghes_estatus_queue_shrink_pool(struct ghes *ghes) { + unsigned long len; + + len = ghes_esource_prealloc_size(ghes->generic); ghes_estatus_pool_size_request -= PAGE_ALIGN(len); } +/* Before adding a queue user, grow the pool */ +static void ghes_estatus_queue_grow_pool(struct ghes *ghes) +{ + unsigned long len; + + len = ghes_esource_prealloc_size(ghes->generic); + ghes_estatus_pool_expand(len); +} + static void ghes_proc_in_irq(struct irq_work *irq_work) { struct llist_node *llnode, *next; @@ -965,48 +1023,22 @@ static LIST_HEAD(ghes_nmi); static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) { - struct ghes *ghes; - int sev, ret = NMI_DONE; + int ret = NMI_DONE; if (!atomic_add_unless(&ghes_in_nmi, 1, 1)) return ret; - list_for_each_entry_rcu(ghes, &ghes_nmi, list) { - if (ghes_read_estatus(ghes, 1)) { - ghes_clear_estatus(ghes); - continue; - } else { - ret = NMI_HANDLED; - } - - sev = ghes_severity(ghes->estatus->error_severity); - if (sev >= GHES_SEV_PANIC) { - oops_begin(); - ghes_print_queued_estatus(); - __ghes_panic(ghes); - } + if (!ghes_estatus_queue_notified(&ghes_nmi)) + ret = NMI_HANDLED; - if (!(ghes->flags & GHES_TO_CLEAR)) - continue; - - __process_error(ghes); - ghes_clear_estatus(ghes); - } - -#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - if (ret == NMI_HANDLED) - irq_work_queue(&ghes_proc_irq_work); -#endif atomic_dec(&ghes_in_nmi); return ret; } static void ghes_nmi_add(struct ghes *ghes) { - unsigned long len; + ghes_estatus_queue_grow_pool(ghes); - len = ghes_esource_prealloc_size(ghes->generic); - ghes_estatus_pool_expand(len); mutex_lock(&ghes_list_mutex); if (list_empty(&ghes_nmi)) register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes"); @@ -1016,8 +1048,6 @@ static void ghes_nmi_add(struct ghes *ghes) static void ghes_nmi_remove(struct ghes *ghes) { - unsigned long len; - mutex_lock(&ghes_list_mutex); list_del_rcu(&ghes->list); if (list_empty(&ghes_nmi)) @@ -1028,8 +1058,8 @@ static void ghes_nmi_remove(struct ghes *ghes) * freed after NMI handler finishes. */ synchronize_rcu(); - len = ghes_esource_prealloc_size(ghes->generic); - ghes_estatus_pool_shrink(len); + + ghes_estatus_queue_shrink_pool(ghes); } #else /* CONFIG_HAVE_ACPI_APEI_NMI */ -- 2.16.2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: james.morse@arm.com (James Morse) Date: Fri, 27 Apr 2018 16:35:00 +0100 Subject: [PATCH v3 02/12] ACPI / APEI: Generalise the estatus queue's add/remove and notify code In-Reply-To: <20180427153510.5799-1-james.morse@arm.com> References: <20180427153510.5799-1-james.morse@arm.com> Message-ID: <20180427153510.5799-3-james.morse@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Refactor the estatus queue's pool grow/shrink code and notification routine from NOTIFY_NMI's handlers. This will allow another notification method to use the estatus queue without duplicating this code. This patch adds rcu_read_lock()/rcu_read_unlock() around the list list_for_each_entry_rcu() walker. These aren't strictly necessary as the whole nmi_enter/nmi_exit() window is a spooky RCU read-side critical section. Keep the oops_begin() call for x86, arm64 doesn't have one of these, and APEI is the only thing outside arch code calling this.. The existing ghes_estatus_pool_shrink() is folded into the new ghes_estatus_queue_shrink_pool() as only the queue uses it. _in_nmi_notify_one() is separate from the rcu-list walker for a later caller that doesn't need to walk a list. Signed-off-by: James Morse Reviewed-by: Punit Agrawal --- Changes since v1: * Tidied up _in_nmi_notify_one(). drivers/acpi/apei/ghes.c | 100 ++++++++++++++++++++++++++++++----------------- 1 file changed, 65 insertions(+), 35 deletions(-) diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index e2af91c92135..c8a6c5b0516e 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -747,6 +747,51 @@ static void __process_error(struct ghes *ghes) #endif } +static int _in_nmi_notify_one(struct ghes *ghes) +{ + int sev; + + if (ghes_read_estatus(ghes, 1)) { + ghes_clear_estatus(ghes); + return -ENOENT; + } + + sev = ghes_severity(ghes->estatus->error_severity); + if (sev >= GHES_SEV_PANIC) { +#ifdef CONFIG_X86 + oops_begin(); +#endif + ghes_print_queued_estatus(); + __ghes_panic(ghes); + } + + if (!(ghes->flags & GHES_TO_CLEAR)) + return 0; + + __process_error(ghes); + ghes_clear_estatus(ghes); + + return 0; +} + +static int ghes_estatus_queue_notified(struct list_head *rcu_list) +{ + int ret = -ENOENT; + struct ghes *ghes; + + rcu_read_lock(); + list_for_each_entry_rcu(ghes, rcu_list, list) { + if (!_in_nmi_notify_one(ghes)) + ret = 0; + } + rcu_read_unlock(); + + if (IS_ENABLED(CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG) && ret == 0) + irq_work_queue(&ghes_proc_irq_work); + + return ret; +} + static unsigned long ghes_esource_prealloc_size( const struct acpi_hest_generic *generic) { @@ -762,11 +807,24 @@ static unsigned long ghes_esource_prealloc_size( return prealloc_size; } -static void ghes_estatus_pool_shrink(unsigned long len) +/* After removing a queue user, we can shrink the pool */ +static void ghes_estatus_queue_shrink_pool(struct ghes *ghes) { + unsigned long len; + + len = ghes_esource_prealloc_size(ghes->generic); ghes_estatus_pool_size_request -= PAGE_ALIGN(len); } +/* Before adding a queue user, grow the pool */ +static void ghes_estatus_queue_grow_pool(struct ghes *ghes) +{ + unsigned long len; + + len = ghes_esource_prealloc_size(ghes->generic); + ghes_estatus_pool_expand(len); +} + static void ghes_proc_in_irq(struct irq_work *irq_work) { struct llist_node *llnode, *next; @@ -965,48 +1023,22 @@ static LIST_HEAD(ghes_nmi); static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs) { - struct ghes *ghes; - int sev, ret = NMI_DONE; + int ret = NMI_DONE; if (!atomic_add_unless(&ghes_in_nmi, 1, 1)) return ret; - list_for_each_entry_rcu(ghes, &ghes_nmi, list) { - if (ghes_read_estatus(ghes, 1)) { - ghes_clear_estatus(ghes); - continue; - } else { - ret = NMI_HANDLED; - } - - sev = ghes_severity(ghes->estatus->error_severity); - if (sev >= GHES_SEV_PANIC) { - oops_begin(); - ghes_print_queued_estatus(); - __ghes_panic(ghes); - } + if (!ghes_estatus_queue_notified(&ghes_nmi)) + ret = NMI_HANDLED; - if (!(ghes->flags & GHES_TO_CLEAR)) - continue; - - __process_error(ghes); - ghes_clear_estatus(ghes); - } - -#ifdef CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG - if (ret == NMI_HANDLED) - irq_work_queue(&ghes_proc_irq_work); -#endif atomic_dec(&ghes_in_nmi); return ret; } static void ghes_nmi_add(struct ghes *ghes) { - unsigned long len; + ghes_estatus_queue_grow_pool(ghes); - len = ghes_esource_prealloc_size(ghes->generic); - ghes_estatus_pool_expand(len); mutex_lock(&ghes_list_mutex); if (list_empty(&ghes_nmi)) register_nmi_handler(NMI_LOCAL, ghes_notify_nmi, 0, "ghes"); @@ -1016,8 +1048,6 @@ static void ghes_nmi_add(struct ghes *ghes) static void ghes_nmi_remove(struct ghes *ghes) { - unsigned long len; - mutex_lock(&ghes_list_mutex); list_del_rcu(&ghes->list); if (list_empty(&ghes_nmi)) @@ -1028,8 +1058,8 @@ static void ghes_nmi_remove(struct ghes *ghes) * freed after NMI handler finishes. */ synchronize_rcu(); - len = ghes_esource_prealloc_size(ghes->generic); - ghes_estatus_pool_shrink(len); + + ghes_estatus_queue_shrink_pool(ghes); } #else /* CONFIG_HAVE_ACPI_APEI_NMI */ -- 2.16.2