From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S3000161AbdEAK4E (ORCPT ); Mon, 1 May 2017 06:56:04 -0400 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35388 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164413AbdEAKzq (ORCPT ); Mon, 1 May 2017 06:55:46 -0400 Date: Mon, 1 May 2017 12:55:39 +0200 From: Ingo Molnar To: Linus Torvalds Cc: linux-kernel@vger.kernel.org, Borislav Petkov , "Luck, Tony" , Thomas Gleixner , "H. Peter Anvin" , Andrew Morton Subject: [GIT PULL] RAS changes for v4.12 Message-ID: <20170501105539.ao72u4ivyr2lszee@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Linus, Please pull the latest ras-core-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git ras-core-for-linus # HEAD: c6a9583fb41c8bd017f643d5bc90a0fe0a92fe43 x86/mce: Check MCi_STATUS[MISCV] for usable addr on Intel only The main changes in this cycle were: - Add the 'Corrected Errors Collector' kernel feature which collect and monitor correctable errors statistics and will preemptively (soft-)offline physical pages that have a suspiciously high error count. - Handle MCE errors during kexec() more gracefully - Factor out and deprecate the /dev/mcelog driver - ... plus misc fixes and cleanpus. Thanks, Ingo ------------------> Borislav Petkov (6): x86/mce: Rename mce_log()'s argument x86/mce: Rename mce_log to mce_log_buffer RAS: Add a Corrected Errors Collector x86/mce: Do not register notifiers with invalid prio x86/mce: Update notifier priority check x86/mce: Check MCi_STATUS[MISCV] for usable addr on Intel only Geliang Tang (1): ACPI/APEI: Use setup_deferrable_timer() Piotr Luc (1): x86/mce: Enable PPIN for Knights Landing/Mill Tony Luck (1): x86/mce: Factor out and deprecate the /dev/mcelog driver Xunlei Pang (1): x86/mce: Handle broadcasted MCE gracefully with kexec Yazen Ghannam (1): x86/mce: Init some CPU features early Documentation/admin-guide/kernel-parameters.txt | 6 + arch/x86/Kconfig | 10 +- arch/x86/include/asm/mce.h | 12 +- arch/x86/include/asm/reboot.h | 1 + arch/x86/kernel/cpu/mcheck/Makefile | 2 + arch/x86/kernel/cpu/mcheck/dev-mcelog.c | 397 +++++++++++++++++ arch/x86/kernel/cpu/mcheck/mce-internal.h | 8 + arch/x86/kernel/cpu/mcheck/mce.c | 561 ++++++------------------ arch/x86/kernel/cpu/mcheck/mce_intel.c | 3 + arch/x86/kernel/reboot.c | 5 +- arch/x86/ras/Kconfig | 14 + drivers/acpi/apei/ghes.c | 5 +- drivers/ras/Makefile | 3 +- drivers/ras/cec.c | 532 ++++++++++++++++++++++ drivers/ras/debugfs.c | 2 +- drivers/ras/debugfs.h | 8 + drivers/ras/ras.c | 11 + include/linux/ras.h | 13 +- 18 files changed, 1154 insertions(+), 439 deletions(-) create mode 100644 arch/x86/kernel/cpu/mcheck/dev-mcelog.c create mode 100644 drivers/ras/cec.c create mode 100644 drivers/ras/debugfs.h diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2ba45caabada..927b8b8854cd 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3172,6 +3172,12 @@ ramdisk_size= [RAM] Sizes of RAM disks in kilobytes See Documentation/blockdev/ramdisk.txt. + ras=option[,option,...] [KNL] RAS-specific options + + cec_disable [X86] + Disable the Correctable Errors Collector, + see CONFIG_RAS_CEC help text. + rcu_nocbs= [KNL] The argument is a cpu list, as described above. diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index cc98d5a294ee..43e6bac6b950 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1043,6 +1043,14 @@ config X86_MCE The action the kernel takes depends on the severity of the problem, ranging from warning messages to halting the machine. +config X86_MCELOG_LEGACY + bool "Support for deprecated /dev/mcelog character device" + depends on X86_MCE + ---help--- + Enable support for /dev/mcelog which is needed by the old mcelog + userspace logging daemon. Consider switching to the new generation + rasdaemon solution. + config X86_MCE_INTEL def_bool y prompt "Intel MCE features" @@ -1072,7 +1080,7 @@ config X86_MCE_THRESHOLD def_bool y config X86_MCE_INJECT - depends on X86_MCE && X86_LOCAL_APIC + depends on X86_MCE && X86_LOCAL_APIC && X86_MCELOG_LEGACY tristate "Machine check injector support" ---help--- Provide support for injecting machine checks for testing purposes. diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index e63873683d4a..4fd5195deed0 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -128,7 +128,7 @@ * debugging tools. Each entry is only valid when its finished flag * is set. */ -struct mce_log { +struct mce_log_buffer { char signature[12]; /* "MACHINECHECK" */ unsigned len; /* = MCE_LOG_LEN */ unsigned next; @@ -191,10 +191,12 @@ extern struct mca_config mca_cfg; extern struct mca_msr_regs msr_ops; enum mce_notifier_prios { - MCE_PRIO_SRAO = INT_MAX, - MCE_PRIO_EXTLOG = INT_MAX - 1, - MCE_PRIO_NFIT = INT_MAX - 2, - MCE_PRIO_EDAC = INT_MAX - 3, + MCE_PRIO_FIRST = INT_MAX, + MCE_PRIO_SRAO = INT_MAX - 1, + MCE_PRIO_EXTLOG = INT_MAX - 2, + MCE_PRIO_NFIT = INT_MAX - 3, + MCE_PRIO_EDAC = INT_MAX - 4, + MCE_PRIO_MCELOG = 1, MCE_PRIO_LOWEST = 0, }; diff --git a/arch/x86/include/asm/reboot.h b/arch/x86/include/asm/reboot.h index 2cb1cc253d51..fc62ba8dce93 100644 --- a/arch/x86/include/asm/reboot.h +++ b/arch/x86/include/asm/reboot.h @@ -15,6 +15,7 @@ struct machine_ops { }; extern struct machine_ops machine_ops; +extern int crashing_cpu; void native_machine_crash_shutdown(struct pt_regs *regs); void native_machine_shutdown(void); diff --git a/arch/x86/kernel/cpu/mcheck/Makefile b/arch/x86/kernel/cpu/mcheck/Makefile index a3311c886194..43051f0777d4 100644 --- a/arch/x86/kernel/cpu/mcheck/Makefile +++ b/arch/x86/kernel/cpu/mcheck/Makefile @@ -9,3 +9,5 @@ obj-$(CONFIG_X86_MCE_INJECT) += mce-inject.o obj-$(CONFIG_X86_THERMAL_VECTOR) += therm_throt.o obj-$(CONFIG_ACPI_APEI) += mce-apei.o + +obj-$(CONFIG_X86_MCELOG_LEGACY) += dev-mcelog.o diff --git a/arch/x86/kernel/cpu/mcheck/dev-mcelog.c b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c new file mode 100644 index 000000000000..9c632cb88546 --- /dev/null +++ b/arch/x86/kernel/cpu/mcheck/dev-mcelog.c @@ -0,0 +1,397 @@ +/* + * /dev/mcelog driver + * + * K8 parts Copyright 2002,2003 Andi Kleen, SuSE Labs. + * Rest from unknown author(s). + * 2004 Andi Kleen. Rewrote most of it. + * Copyright 2008 Intel Corporation + * Author: Andi Kleen + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include + +#include "mce-internal.h" + +static DEFINE_MUTEX(mce_chrdev_read_mutex); + +static char mce_helper[128]; +static char *mce_helper_argv[2] = { mce_helper, NULL }; + +#define mce_log_get_idx_check(p) \ +({ \ + RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ + !lockdep_is_held(&mce_chrdev_read_mutex), \ + "suspicious mce_log_get_idx_check() usage"); \ + smp_load_acquire(&(p)); \ +}) + +/* + * Lockless MCE logging infrastructure. + * This avoids deadlocks on printk locks without having to break locks. Also + * separate MCEs from kernel messages to avoid bogus bug reports. + */ + +static struct mce_log_buffer mcelog = { + .signature = MCE_LOG_SIGNATURE, + .len = MCE_LOG_LEN, + .recordlen = sizeof(struct mce), +}; + +static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait); + +/* User mode helper program triggered by machine check event */ +extern char mce_helper[128]; + +static int dev_mce_log(struct notifier_block *nb, unsigned long val, + void *data) +{ + struct mce *mce = (struct mce *)data; + unsigned int next, entry; + + wmb(); + for (;;) { + entry = mce_log_get_idx_check(mcelog.next); + for (;;) { + + /* + * When the buffer fills up discard new entries. + * Assume that the earlier errors are the more + * interesting ones: + */ + if (entry >= MCE_LOG_LEN) { + set_bit(MCE_OVERFLOW, + (unsigned long *)&mcelog.flags); + return NOTIFY_OK; + } + /* Old left over entry. Skip: */ + if (mcelog.entry[entry].finished) { + entry++; + continue; + } + break; + } + smp_rmb(); + next = entry + 1; + if (cmpxchg(&mcelog.next, entry, next) == entry) + break; + } + memcpy(mcelog.entry + entry, mce, sizeof(struct mce)); + wmb(); + mcelog.entry[entry].finished = 1; + wmb(); + + /* wake processes polling /dev/mcelog */ + wake_up_interruptible(&mce_chrdev_wait); + + return NOTIFY_OK; +} + +static struct notifier_block dev_mcelog_nb = { + .notifier_call = dev_mce_log, + .priority = MCE_PRIO_MCELOG, +}; + +static void mce_do_trigger(struct work_struct *work) +{ + call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT); +} + +static DECLARE_WORK(mce_trigger_work, mce_do_trigger); + + +void mce_work_trigger(void) +{ + if (mce_helper[0]) + schedule_work(&mce_trigger_work); +} + +static ssize_t +show_trigger(struct device *s, struct device_attribute *attr, char *buf) +{ + strcpy(buf, mce_helper); + strcat(buf, "\n"); + return strlen(mce_helper) + 1; +} + +static ssize_t set_trigger(struct device *s, struct device_attribute *attr, + const char *buf, size_t siz) +{ + char *p; + + strncpy(mce_helper, buf, sizeof(mce_helper)); + mce_helper[sizeof(mce_helper)-1] = 0; + p = strchr(mce_helper, '\n'); + + if (p) + *p = 0; + + return strlen(mce_helper) + !!p; +} + +DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger); + +/* + * mce_chrdev: Character device /dev/mcelog to read and clear the MCE log. + */ + +static DEFINE_SPINLOCK(mce_chrdev_state_lock); +static int mce_chrdev_open_count; /* #times opened */ +static int mce_chrdev_open_exclu; /* already open exclusive? */ + +static int mce_chrdev_open(struct inode *inode, struct file *file) +{ + spin_lock(&mce_chrdev_state_lock); + + if (mce_chrdev_open_exclu || + (mce_chrdev_open_count && (file->f_flags & O_EXCL))) { + spin_unlock(&mce_chrdev_state_lock); + + return -EBUSY; + } + + if (file->f_flags & O_EXCL) + mce_chrdev_open_exclu = 1; + mce_chrdev_open_count++; + + spin_unlock(&mce_chrdev_state_lock); + + return nonseekable_open(inode, file); +} + +static int mce_chrdev_release(struct inode *inode, struct file *file) +{ + spin_lock(&mce_chrdev_state_lock); + + mce_chrdev_open_count--; + mce_chrdev_open_exclu = 0; + + spin_unlock(&mce_chrdev_state_lock); + + return 0; +} + +static void collect_tscs(void *data) +{ + unsigned long *cpu_tsc = (unsigned long *)data; + + cpu_tsc[smp_processor_id()] = rdtsc(); +} + +static int mce_apei_read_done; + +/* Collect MCE record of previous boot in persistent storage via APEI ERST. */ +static int __mce_read_apei(char __user **ubuf, size_t usize) +{ + int rc; + u64 record_id; + struct mce m; + + if (usize < sizeof(struct mce)) + return -EINVAL; + + rc = apei_read_mce(&m, &record_id); + /* Error or no more MCE record */ + if (rc <= 0) { + mce_apei_read_done = 1; + /* + * When ERST is disabled, mce_chrdev_read() should return + * "no record" instead of "no device." + */ + if (rc == -ENODEV) + return 0; + return rc; + } + rc = -EFAULT; + if (copy_to_user(*ubuf, &m, sizeof(struct mce))) + return rc; + /* + * In fact, we should have cleared the record after that has + * been flushed to the disk or sent to network in + * /sbin/mcelog, but we have no interface to support that now, + * so just clear it to avoid duplication. + */ + rc = apei_clear_mce(record_id); + if (rc) { + mce_apei_read_done = 1; + return rc; + } + *ubuf += sizeof(struct mce); + + return 0; +} + +static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf, + size_t usize, loff_t *off) +{ + char __user *buf = ubuf; + unsigned long *cpu_tsc; + unsigned prev, next; + int i, err; + + cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL); + if (!cpu_tsc) + return -ENOMEM; + + mutex_lock(&mce_chrdev_read_mutex); + + if (!mce_apei_read_done) { + err = __mce_read_apei(&buf, usize); + if (err || buf != ubuf) + goto out; + } + + next = mce_log_get_idx_check(mcelog.next); + + /* Only supports full reads right now */ + err = -EINVAL; + if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) + goto out; + + err = 0; + prev = 0; + do { + for (i = prev; i < next; i++) { + unsigned long start = jiffies; + struct mce *m = &mcelog.entry[i]; + + while (!m->finished) { + if (time_after_eq(jiffies, start + 2)) { + memset(m, 0, sizeof(*m)); + goto timeout; + } + cpu_relax(); + } + smp_rmb(); + err |= copy_to_user(buf, m, sizeof(*m)); + buf += sizeof(*m); +timeout: + ; + } + + memset(mcelog.entry + prev, 0, + (next - prev) * sizeof(struct mce)); + prev = next; + next = cmpxchg(&mcelog.next, prev, 0); + } while (next != prev); + + synchronize_sched(); + + /* + * Collect entries that were still getting written before the + * synchronize. + */ + on_each_cpu(collect_tscs, cpu_tsc, 1); + + for (i = next; i < MCE_LOG_LEN; i++) { + struct mce *m = &mcelog.entry[i]; + + if (m->finished && m->tsc < cpu_tsc[m->cpu]) { + err |= copy_to_user(buf, m, sizeof(*m)); + smp_rmb(); + buf += sizeof(*m); + memset(m, 0, sizeof(*m)); + } + } + + if (err) + err = -EFAULT; + +out: + mutex_unlock(&mce_chrdev_read_mutex); + kfree(cpu_tsc); + + return err ? err : buf - ubuf; +} + +static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait) +{ + poll_wait(file, &mce_chrdev_wait, wait); + if (READ_ONCE(mcelog.next)) + return POLLIN | POLLRDNORM; + if (!mce_apei_read_done && apei_check_mce()) + return POLLIN | POLLRDNORM; + return 0; +} + +static long mce_chrdev_ioctl(struct file *f, unsigned int cmd, + unsigned long arg) +{ + int __user *p = (int __user *)arg; + + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + switch (cmd) { + case MCE_GET_RECORD_LEN: + return put_user(sizeof(struct mce), p); + case MCE_GET_LOG_LEN: + return put_user(MCE_LOG_LEN, p); + case MCE_GETCLEAR_FLAGS: { + unsigned flags; + + do { + flags = mcelog.flags; + } while (cmpxchg(&mcelog.flags, flags, 0) != flags); + + return put_user(flags, p); + } + default: + return -ENOTTY; + } +} + +static ssize_t (*mce_write)(struct file *filp, const char __user *ubuf, + size_t usize, loff_t *off); + +void register_mce_write_callback(ssize_t (*fn)(struct file *filp, + const char __user *ubuf, + size_t usize, loff_t *off)) +{ + mce_write = fn; +} +EXPORT_SYMBOL_GPL(register_mce_write_callback); + +static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf, + size_t usize, loff_t *off) +{ + if (mce_write) + return mce_write(filp, ubuf, usize, off); + else + return -EINVAL; +} + +static const struct file_operations mce_chrdev_ops = { + .open = mce_chrdev_open, + .release = mce_chrdev_release, + .read = mce_chrdev_read, + .write = mce_chrdev_write, + .poll = mce_chrdev_poll, + .unlocked_ioctl = mce_chrdev_ioctl, + .llseek = no_llseek, +}; + +static struct miscdevice mce_chrdev_device = { + MISC_MCELOG_MINOR, + "mcelog", + &mce_chrdev_ops, +}; + +static __init int dev_mcelog_init_device(void) +{ + int err; + + /* register character device /dev/mcelog */ + err = misc_register(&mce_chrdev_device); + if (err) { + pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err); + return err; + } + mce_register_decode_chain(&dev_mcelog_nb); + return 0; +} +device_initcall_sync(dev_mcelog_init_device); diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h index 903043e6a62b..7f2a7c54391f 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-internal.h +++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h @@ -96,3 +96,11 @@ static inline bool mce_cmp(struct mce *m1, struct mce *m2) m1->addr != m2->addr || m1->misc != m2->misc; } + +extern struct device_attribute dev_attr_trigger; + +#ifdef CONFIG_X86_MCELOG_LEGACY +extern void mce_work_trigger(void); +#else +static inline void mce_work_trigger(void) { } +#endif diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 5accfbdee3f0..4a29f7481761 100644 --- a/arch/x86/kernel/cpu/mcheck/mce.c +++ b/arch/x86/kernel/cpu/mcheck/mce.c @@ -35,6 +35,7 @@ #include #include #include +#include #include #include #include @@ -49,20 +50,11 @@ #include #include #include +#include #include "mce-internal.h" -static DEFINE_MUTEX(mce_chrdev_read_mutex); - -static int mce_chrdev_open_count; /* #times opened */ - -#define mce_log_get_idx_check(p) \ -({ \ - RCU_LOCKDEP_WARN(!rcu_read_lock_sched_held() && \ - !lockdep_is_held(&mce_chrdev_read_mutex), \ - "suspicious mce_log_get_idx_check() usage"); \ - smp_load_acquire(&(p)); \ -}) +static DEFINE_MUTEX(mce_log_mutex); #define CREATE_TRACE_POINTS #include @@ -87,15 +79,9 @@ struct mca_config mca_cfg __read_mostly = { .monarch_timeout = -1 }; -/* User mode helper program triggered by machine check event */ -static unsigned long mce_need_notify; -static char mce_helper[128]; -static char *mce_helper_argv[2] = { mce_helper, NULL }; - -static DECLARE_WAIT_QUEUE_HEAD(mce_chrdev_wait); - static DEFINE_PER_CPU(struct mce, mces_seen); -static int cpu_missing; +static unsigned long mce_need_notify; +static int cpu_missing; /* * MCA banks polled by the period polling timer for corrected events. @@ -145,80 +131,36 @@ void mce_setup(struct mce *m) DEFINE_PER_CPU(struct mce, injectm); EXPORT_PER_CPU_SYMBOL_GPL(injectm); -/* - * Lockless MCE logging infrastructure. - * This avoids deadlocks on printk locks without having to break locks. Also - * separate MCEs from kernel messages to avoid bogus bug reports. - */ - -static struct mce_log mcelog = { - .signature = MCE_LOG_SIGNATURE, - .len = MCE_LOG_LEN, - .recordlen = sizeof(struct mce), -}; - -void mce_log(struct mce *mce) +void mce_log(struct mce *m) { - unsigned next, entry; - - /* Emit the trace record: */ - trace_mce_record(mce); - - if (!mce_gen_pool_add(mce)) + if (!mce_gen_pool_add(m)) irq_work_queue(&mce_irq_work); - - wmb(); - for (;;) { - entry = mce_log_get_idx_check(mcelog.next); - for (;;) { - - /* - * When the buffer fills up discard new entries. - * Assume that the earlier errors are the more - * interesting ones: - */ - if (entry >= MCE_LOG_LEN) { - set_bit(MCE_OVERFLOW, - (unsigned long *)&mcelog.flags); - return; - } - /* Old left over entry. Skip: */ - if (mcelog.entry[entry].finished) { - entry++; - continue; - } - break; - } - smp_rmb(); - next = entry + 1; - if (cmpxchg(&mcelog.next, entry, next) == entry) - break; - } - memcpy(mcelog.entry + entry, mce, sizeof(struct mce)); - wmb(); - mcelog.entry[entry].finished = 1; - wmb(); - - set_bit(0, &mce_need_notify); } void mce_inject_log(struct mce *m) { - mutex_lock(&mce_chrdev_read_mutex); + mutex_lock(&mce_log_mutex); mce_log(m); - mutex_unlock(&mce_chrdev_read_mutex); + mutex_unlock(&mce_log_mutex); } EXPORT_SYMBOL_GPL(mce_inject_log); static struct notifier_block mce_srao_nb; +/* + * We run the default notifier if we have only the SRAO, the first and the + * default notifier registered. I.e., the mandatory NUM_DEFAULT_NOTIFIERS + * notifiers registered on the chain. + */ +#define NUM_DEFAULT_NOTIFIERS 3 static atomic_t num_notifiers; void mce_register_decode_chain(struct notifier_block *nb) { - atomic_inc(&num_notifiers); + if (WARN_ON(nb->priority > MCE_PRIO_MCELOG && nb->priority < MCE_PRIO_EDAC)) + return; - WARN_ON(nb->priority > MCE_PRIO_LOWEST && nb->priority < MCE_PRIO_EDAC); + atomic_inc(&num_notifiers); atomic_notifier_chain_register(&x86_mce_decoder_chain, nb); } @@ -521,7 +463,6 @@ static void mce_schedule_work(void) static void mce_irq_work_cb(struct irq_work *entry) { - mce_notify_irq(); mce_schedule_work(); } @@ -550,20 +491,97 @@ static void mce_report_event(struct pt_regs *regs) */ static int mce_usable_address(struct mce *m) { - if (!(m->status & MCI_STATUS_MISCV) || !(m->status & MCI_STATUS_ADDRV)) + if (!(m->status & MCI_STATUS_ADDRV)) return 0; /* Checks after this one are Intel-specific: */ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) return 1; + if (!(m->status & MCI_STATUS_MISCV)) + return 0; + if (MCI_MISC_ADDR_LSB(m->misc) > PAGE_SHIFT) return 0; + if (MCI_MISC_ADDR_MODE(m->misc) != MCI_MISC_ADDR_PHYS) return 0; + return 1; } +static bool memory_error(struct mce *m) +{ + struct cpuinfo_x86 *c = &boot_cpu_data; + + if (c->x86_vendor == X86_VENDOR_AMD) { + /* ErrCodeExt[20:16] */ + u8 xec = (m->status >> 16) & 0x1f; + + return (xec == 0x0 || xec == 0x8); + } else if (c->x86_vendor == X86_VENDOR_INTEL) { + /* + * Intel SDM Volume 3B - 15.9.2 Compound Error Codes + * + * Bit 7 of the MCACOD field of IA32_MCi_STATUS is used for + * indicating a memory error. Bit 8 is used for indicating a + * cache hierarchy error. The combination of bit 2 and bit 3 + * is used for indicating a `generic' cache hierarchy error + * But we can't just blindly check the above bits, because if + * bit 11 is set, then it is a bus/interconnect error - and + * either way the above bits just gives more detail on what + * bus/interconnect error happened. Note that bit 12 can be + * ignored, as it's the "filter" bit. + */ + return (m->status & 0xef80) == BIT(7) || + (m->status & 0xef00) == BIT(8) || + (m->status & 0xeffc) == 0xc; + } + + return false; +} + +static bool cec_add_mce(struct mce *m) +{ + if (!m) + return false; + + /* We eat only correctable DRAM errors with usable addresses. */ + if (memory_error(m) && + !(m->status & MCI_STATUS_UC) && + mce_usable_address(m)) + if (!cec_add_elem(m->addr >> PAGE_SHIFT)) + return true; + + return false; +} + +static int mce_first_notifier(struct notifier_block *nb, unsigned long val, + void *data) +{ + struct mce *m = (struct mce *)data; + + if (!m) + return NOTIFY_DONE; + + if (cec_add_mce(m)) + return NOTIFY_STOP; + + /* Emit the trace record: */ + trace_mce_record(m); + + set_bit(0, &mce_need_notify); + + mce_notify_irq(); + + return NOTIFY_DONE; +} + +static struct notifier_block first_nb = { + .notifier_call = mce_first_notifier, + .priority = MCE_PRIO_FIRST, +}; + static int srao_decode_notifier(struct notifier_block *nb, unsigned long val, void *data) { @@ -593,15 +611,7 @@ static int mce_default_notifier(struct notifier_block *nb, unsigned long val, if (!m) return NOTIFY_DONE; - /* - * Run the default notifier if we have only the SRAO - * notifier and us registered. - */ - if (atomic_read(&num_notifiers) > 2) - return NOTIFY_DONE; - - /* Don't print when mcelog is running */ - if (mce_chrdev_open_count > 0) + if (atomic_read(&num_notifiers) > NUM_DEFAULT_NOTIFIERS) return NOTIFY_DONE; __print_mce(m); @@ -654,37 +664,6 @@ static void mce_read_aux(struct mce *m, int i) } } -static bool memory_error(struct mce *m) -{ - struct cpuinfo_x86 *c = &boot_cpu_data; - - if (c->x86_vendor == X86_VENDOR_AMD) { - /* ErrCodeExt[20:16] */ - u8 xec = (m->status >> 16) & 0x1f; - - return (xec == 0x0 || xec == 0x8); - } else if (c->x86_vendor == X86_VENDOR_INTEL) { - /* - * Intel SDM Volume 3B - 15.9.2 Compound Error Codes - * - * Bit 7 of the MCACOD field of IA32_MCi_STATUS is used for - * indicating a memory error. Bit 8 is used for indicating a - * cache hierarchy error. The combination of bit 2 and bit 3 - * is used for indicating a `generic' cache hierarchy error - * But we can't just blindly check the above bits, because if - * bit 11 is set, then it is a bus/interconnect error - and - * either way the above bits just gives more detail on what - * bus/interconnect error happened. Note that bit 12 can be - * ignored, as it's the "filter" bit. - */ - return (m->status & 0xef80) == BIT(7) || - (m->status & 0xef00) == BIT(8) || - (m->status & 0xeffc) == 0xc; - } - - return false; -} - DEFINE_PER_CPU(unsigned, mce_poll_count); /* @@ -1133,9 +1112,22 @@ void do_machine_check(struct pt_regs *regs, long error_code) * on Intel. */ int lmce = 1; + int cpu = smp_processor_id(); - /* If this CPU is offline, just bail out. */ - if (cpu_is_offline(smp_processor_id())) { + /* + * Cases where we avoid rendezvous handler timeout: + * 1) If this CPU is offline. + * + * 2) If crashing_cpu was set, e.g. we're entering kdump and we need to + * skip those CPUs which remain looping in the 1st kernel - see + * crash_nmi_callback(). + * + * Note: there still is a small window between kexec-ing and the new, + * kdump kernel establishing a new #MC handler where a broadcasted MCE + * might not get handled properly. + */ + if (cpu_is_offline(cpu) || + (crashing_cpu != -1 && crashing_cpu != cpu)) { u64 mcgstatus; mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS); @@ -1405,13 +1397,6 @@ static void mce_timer_delete_all(void) del_timer_sync(&per_cpu(mce_timer, cpu)); } -static void mce_do_trigger(struct work_struct *work) -{ - call_usermodehelper(mce_helper, mce_helper_argv, NULL, UMH_NO_WAIT); -} - -static DECLARE_WORK(mce_trigger_work, mce_do_trigger); - /* * Notify the user(s) about new machine check events. * Can be called from interrupt context, but not from machine check/NMI @@ -1423,11 +1408,7 @@ int mce_notify_irq(void) static DEFINE_RATELIMIT_STATE(ratelimit, 60*HZ, 2); if (test_and_clear_bit(0, &mce_need_notify)) { - /* wake processes polling /dev/mcelog */ - wake_up_interruptible(&mce_chrdev_wait); - - if (mce_helper[0]) - schedule_work(&mce_trigger_work); + mce_work_trigger(); if (__ratelimit(&ratelimit)) pr_info(HW_ERR "Machine check events logged\n"); @@ -1694,30 +1675,35 @@ static int __mcheck_cpu_ancient_init(struct cpuinfo_x86 *c) return 0; } -static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c) +/* + * Init basic CPU features needed for early decoding of MCEs. + */ +static void __mcheck_cpu_init_early(struct cpuinfo_x86 *c) { - switch (c->x86_vendor) { - case X86_VENDOR_INTEL: - mce_intel_feature_init(c); - mce_adjust_timer = cmci_intel_adjust_timer; - break; - - case X86_VENDOR_AMD: { + if (c->x86_vendor == X86_VENDOR_AMD) { mce_flags.overflow_recov = !!cpu_has(c, X86_FEATURE_OVERFLOW_RECOV); mce_flags.succor = !!cpu_has(c, X86_FEATURE_SUCCOR); mce_flags.smca = !!cpu_has(c, X86_FEATURE_SMCA); - /* - * Install proper ops for Scalable MCA enabled processors - */ if (mce_flags.smca) { msr_ops.ctl = smca_ctl_reg; msr_ops.status = smca_status_reg; msr_ops.addr = smca_addr_reg; msr_ops.misc = smca_misc_reg; } - mce_amd_feature_init(c); + } +} + +static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c) +{ + switch (c->x86_vendor) { + case X86_VENDOR_INTEL: + mce_intel_feature_init(c); + mce_adjust_timer = cmci_intel_adjust_timer; + break; + case X86_VENDOR_AMD: { + mce_amd_feature_init(c); break; } @@ -1804,6 +1790,7 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c) machine_check_vector = do_machine_check; + __mcheck_cpu_init_early(c); __mcheck_cpu_init_generic(); __mcheck_cpu_init_vendor(c); __mcheck_cpu_init_clear_banks(); @@ -1829,251 +1816,6 @@ void mcheck_cpu_clear(struct cpuinfo_x86 *c) } -/* - * mce_chrdev: Character device /dev/mcelog to read and clear the MCE log. - */ - -static DEFINE_SPINLOCK(mce_chrdev_state_lock); -static int mce_chrdev_open_exclu; /* already open exclusive? */ - -static int mce_chrdev_open(struct inode *inode, struct file *file) -{ - spin_lock(&mce_chrdev_state_lock); - - if (mce_chrdev_open_exclu || - (mce_chrdev_open_count && (file->f_flags & O_EXCL))) { - spin_unlock(&mce_chrdev_state_lock); - - return -EBUSY; - } - - if (file->f_flags & O_EXCL) - mce_chrdev_open_exclu = 1; - mce_chrdev_open_count++; - - spin_unlock(&mce_chrdev_state_lock); - - return nonseekable_open(inode, file); -} - -static int mce_chrdev_release(struct inode *inode, struct file *file) -{ - spin_lock(&mce_chrdev_state_lock); - - mce_chrdev_open_count--; - mce_chrdev_open_exclu = 0; - - spin_unlock(&mce_chrdev_state_lock); - - return 0; -} - -static void collect_tscs(void *data) -{ - unsigned long *cpu_tsc = (unsigned long *)data; - - cpu_tsc[smp_processor_id()] = rdtsc(); -} - -static int mce_apei_read_done; - -/* Collect MCE record of previous boot in persistent storage via APEI ERST. */ -static int __mce_read_apei(char __user **ubuf, size_t usize) -{ - int rc; - u64 record_id; - struct mce m; - - if (usize < sizeof(struct mce)) - return -EINVAL; - - rc = apei_read_mce(&m, &record_id); - /* Error or no more MCE record */ - if (rc <= 0) { - mce_apei_read_done = 1; - /* - * When ERST is disabled, mce_chrdev_read() should return - * "no record" instead of "no device." - */ - if (rc == -ENODEV) - return 0; - return rc; - } - rc = -EFAULT; - if (copy_to_user(*ubuf, &m, sizeof(struct mce))) - return rc; - /* - * In fact, we should have cleared the record after that has - * been flushed to the disk or sent to network in - * /sbin/mcelog, but we have no interface to support that now, - * so just clear it to avoid duplication. - */ - rc = apei_clear_mce(record_id); - if (rc) { - mce_apei_read_done = 1; - return rc; - } - *ubuf += sizeof(struct mce); - - return 0; -} - -static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf, - size_t usize, loff_t *off) -{ - char __user *buf = ubuf; - unsigned long *cpu_tsc; - unsigned prev, next; - int i, err; - - cpu_tsc = kmalloc(nr_cpu_ids * sizeof(long), GFP_KERNEL); - if (!cpu_tsc) - return -ENOMEM; - - mutex_lock(&mce_chrdev_read_mutex); - - if (!mce_apei_read_done) { - err = __mce_read_apei(&buf, usize); - if (err || buf != ubuf) - goto out; - } - - next = mce_log_get_idx_check(mcelog.next); - - /* Only supports full reads right now */ - err = -EINVAL; - if (*off != 0 || usize < MCE_LOG_LEN*sizeof(struct mce)) - goto out; - - err = 0; - prev = 0; - do { - for (i = prev; i < next; i++) { - unsigned long start = jiffies; - struct mce *m = &mcelog.entry[i]; - - while (!m->finished) { - if (time_after_eq(jiffies, start + 2)) { - memset(m, 0, sizeof(*m)); - goto timeout; - } - cpu_relax(); - } - smp_rmb(); - err |= copy_to_user(buf, m, sizeof(*m)); - buf += sizeof(*m); -timeout: - ; - } - - memset(mcelog.entry + prev, 0, - (next - prev) * sizeof(struct mce)); - prev = next; - next = cmpxchg(&mcelog.next, prev, 0); - } while (next != prev); - - synchronize_sched(); - - /* - * Collect entries that were still getting written before the - * synchronize. - */ - on_each_cpu(collect_tscs, cpu_tsc, 1); - - for (i = next; i < MCE_LOG_LEN; i++) { - struct mce *m = &mcelog.entry[i]; - - if (m->finished && m->tsc < cpu_tsc[m->cpu]) { - err |= copy_to_user(buf, m, sizeof(*m)); - smp_rmb(); - buf += sizeof(*m); - memset(m, 0, sizeof(*m)); - } - } - - if (err) - err = -EFAULT; - -out: - mutex_unlock(&mce_chrdev_read_mutex); - kfree(cpu_tsc); - - return err ? err : buf - ubuf; -} - -static unsigned int mce_chrdev_poll(struct file *file, poll_table *wait) -{ - poll_wait(file, &mce_chrdev_wait, wait); - if (READ_ONCE(mcelog.next)) - return POLLIN | POLLRDNORM; - if (!mce_apei_read_done && apei_check_mce()) - return POLLIN | POLLRDNORM; - return 0; -} - -static long mce_chrdev_ioctl(struct file *f, unsigned int cmd, - unsigned long arg) -{ - int __user *p = (int __user *)arg; - - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; - - switch (cmd) { - case MCE_GET_RECORD_LEN: - return put_user(sizeof(struct mce), p); - case MCE_GET_LOG_LEN: - return put_user(MCE_LOG_LEN, p); - case MCE_GETCLEAR_FLAGS: { - unsigned flags; - - do { - flags = mcelog.flags; - } while (cmpxchg(&mcelog.flags, flags, 0) != flags); - - return put_user(flags, p); - } - default: - return -ENOTTY; - } -} - -static ssize_t (*mce_write)(struct file *filp, const char __user *ubuf, - size_t usize, loff_t *off); - -void register_mce_write_callback(ssize_t (*fn)(struct file *filp, - const char __user *ubuf, - size_t usize, loff_t *off)) -{ - mce_write = fn; -} -EXPORT_SYMBOL_GPL(register_mce_write_callback); - -static ssize_t mce_chrdev_write(struct file *filp, const char __user *ubuf, - size_t usize, loff_t *off) -{ - if (mce_write) - return mce_write(filp, ubuf, usize, off); - else - return -EINVAL; -} - -static const struct file_operations mce_chrdev_ops = { - .open = mce_chrdev_open, - .release = mce_chrdev_release, - .read = mce_chrdev_read, - .write = mce_chrdev_write, - .poll = mce_chrdev_poll, - .unlocked_ioctl = mce_chrdev_ioctl, - .llseek = no_llseek, -}; - -static struct miscdevice mce_chrdev_device = { - MISC_MCELOG_MINOR, - "mcelog", - &mce_chrdev_ops, -}; - static void __mce_disable_bank(void *arg) { int bank = *((int *)arg); @@ -2147,6 +1889,7 @@ __setup("mce", mcheck_enable); int __init mcheck_init(void) { mcheck_intel_therm_init(); + mce_register_decode_chain(&first_nb); mce_register_decode_chain(&mce_srao_nb); mce_register_decode_chain(&mce_default_nb); mcheck_vendor_init_severity(); @@ -2291,29 +2034,6 @@ static ssize_t set_bank(struct device *s, struct device_attribute *attr, return size; } -static ssize_t -show_trigger(struct device *s, struct device_attribute *attr, char *buf) -{ - strcpy(buf, mce_helper); - strcat(buf, "\n"); - return strlen(mce_helper) + 1; -} - -static ssize_t set_trigger(struct device *s, struct device_attribute *attr, - const char *buf, size_t siz) -{ - char *p; - - strncpy(mce_helper, buf, sizeof(mce_helper)); - mce_helper[sizeof(mce_helper)-1] = 0; - p = strchr(mce_helper, '\n'); - - if (p) - *p = 0; - - return strlen(mce_helper) + !!p; -} - static ssize_t set_ignore_ce(struct device *s, struct device_attribute *attr, const char *buf, size_t size) @@ -2370,7 +2090,6 @@ static ssize_t store_int_with_restart(struct device *s, return ret; } -static DEVICE_ATTR(trigger, 0644, show_trigger, set_trigger); static DEVICE_INT_ATTR(tolerant, 0644, mca_cfg.tolerant); static DEVICE_INT_ATTR(monarch_timeout, 0644, mca_cfg.monarch_timeout); static DEVICE_BOOL_ATTR(dont_log_ce, 0644, mca_cfg.dont_log_ce); @@ -2393,7 +2112,9 @@ static struct dev_ext_attribute dev_attr_cmci_disabled = { static struct device_attribute *mce_device_attrs[] = { &dev_attr_tolerant.attr, &dev_attr_check_interval.attr, +#ifdef CONFIG_X86_MCELOG_LEGACY &dev_attr_trigger, +#endif &dev_attr_monarch_timeout.attr, &dev_attr_dont_log_ce.attr, &dev_attr_ignore_ce.attr, @@ -2567,7 +2288,6 @@ static __init void mce_init_banks(void) static __init int mcheck_init_device(void) { - enum cpuhp_state hp_online; int err; if (!mce_available(&boot_cpu_data)) { @@ -2595,21 +2315,11 @@ static __init int mcheck_init_device(void) mce_cpu_online, mce_cpu_pre_down); if (err < 0) goto err_out_online; - hp_online = err; register_syscore_ops(&mce_syscore_ops); - /* register character device /dev/mcelog */ - err = misc_register(&mce_chrdev_device); - if (err) - goto err_register; - return 0; -err_register: - unregister_syscore_ops(&mce_syscore_ops); - cpuhp_remove_state(hp_online); - err_out_online: cpuhp_remove_state(CPUHP_X86_MCE_DEAD); @@ -2617,7 +2327,7 @@ static __init int mcheck_init_device(void) free_cpumask_var(mce_device_initialized); err_out: - pr_err("Unable to init device /dev/mcelog (rc: %d)\n", err); + pr_err("Unable to init MCE device (rc: %d)\n", err); return err; } @@ -2696,6 +2406,7 @@ static int __init mcheck_late_init(void) static_branch_inc(&mcsafe_key); mcheck_debugfs_init(); + cec_init(); /* * Flush out everything that has been logged during early boot, now that diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c index 190b3e6cef4d..e84db79ef272 100644 --- a/arch/x86/kernel/cpu/mcheck/mce_intel.c +++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c @@ -481,6 +481,9 @@ static void intel_ppin_init(struct cpuinfo_x86 *c) case INTEL_FAM6_BROADWELL_XEON_D: case INTEL_FAM6_BROADWELL_X: case INTEL_FAM6_SKYLAKE_X: + case INTEL_FAM6_XEON_PHI_KNL: + case INTEL_FAM6_XEON_PHI_KNM: + if (rdmsrl_safe(MSR_PPIN_CTL, &val)) return; diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c index 067f9813fd2c..2544700a2a87 100644 --- a/arch/x86/kernel/reboot.c +++ b/arch/x86/kernel/reboot.c @@ -765,10 +765,11 @@ void machine_crash_shutdown(struct pt_regs *regs) #endif +/* This is the CPU performing the emergency shutdown work. */ +int crashing_cpu = -1; + #if defined(CONFIG_SMP) -/* This keeps a track of which one is crashing cpu. */ -static int crashing_cpu; static nmi_shootdown_cb shootdown_callback; static atomic_t waiting_for_crash_ipi; diff --git a/arch/x86/ras/Kconfig b/arch/x86/ras/Kconfig index 0bc60a308730..2a2d89d39af6 100644 --- a/arch/x86/ras/Kconfig +++ b/arch/x86/ras/Kconfig @@ -7,3 +7,17 @@ config MCE_AMD_INJ aspects of the MCE handling code. WARNING: Do not even assume this interface is staying stable! + +config RAS_CEC + bool "Correctable Errors Collector" + depends on X86_MCE && MEMORY_FAILURE && DEBUG_FS + ---help--- + This is a small cache which collects correctable memory errors per 4K + page PFN and counts their repeated occurrence. Once the counter for a + PFN overflows, we try to soft-offline that page as we take it to mean + that it has reached a relatively high error count and would probably + be best if we don't use it anymore. + + Bear in mind that this is absolutely useless if your platform doesn't + have ECC DIMMs and doesn't have DRAM ECC checking enabled in the BIOS. + diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c index b192b42a8351..33ca1968512f 100644 --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -1005,9 +1005,8 @@ static int ghes_probe(struct platform_device *ghes_dev) switch (generic->notify.type) { case ACPI_HEST_NOTIFY_POLLED: - ghes->timer.function = ghes_poll_func; - ghes->timer.data = (unsigned long)ghes; - init_timer_deferrable(&ghes->timer); + setup_deferrable_timer(&ghes->timer, ghes_poll_func, + (unsigned long)ghes); ghes_add_timer(ghes); break; case ACPI_HEST_NOTIFY_EXTERNAL: diff --git a/drivers/ras/Makefile b/drivers/ras/Makefile index d7f73341ced3..7b26dd3aa5d0 100644 --- a/drivers/ras/Makefile +++ b/drivers/ras/Makefile @@ -1 +1,2 @@ -obj-$(CONFIG_RAS) += ras.o debugfs.o +obj-$(CONFIG_RAS) += ras.o debugfs.o +obj-$(CONFIG_RAS_CEC) += cec.o diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c new file mode 100644 index 000000000000..6aab46d91d33 --- /dev/null +++ b/drivers/ras/cec.c @@ -0,0 +1,532 @@ +#include +#include +#include + +#include + +#include "debugfs.h" + +/* + * RAS Correctable Errors Collector + * + * This is a simple gadget which collects correctable errors and counts their + * occurrence per physical page address. + * + * We've opted for possibly the simplest data structure to collect those - an + * array of the size of a memory page. It stores 512 u64's with the following + * structure: + * + * [63 ... PFN ... 12 | 11 ... generation ... 10 | 9 ... count ... 0] + * + * The generation in the two highest order bits is two bits which are set to 11b + * on every insertion. During the course of each entry's existence, the + * generation field gets decremented during spring cleaning to 10b, then 01b and + * then 00b. + * + * This way we're employing the natural numeric ordering to make sure that newly + * inserted/touched elements have higher 12-bit counts (which we've manufactured) + * and thus iterating over the array initially won't kick out those elements + * which were inserted last. + * + * Spring cleaning is what we do when we reach a certain number CLEAN_ELEMS of + * elements entered into the array, during which, we're decaying all elements. + * If, after decay, an element gets inserted again, its generation is set to 11b + * to make sure it has higher numerical count than other, older elements and + * thus emulate an an LRU-like behavior when deleting elements to free up space + * in the page. + * + * When an element reaches it's max count of count_threshold, we try to poison + * it by assuming that errors triggered count_threshold times in a single page + * are excessive and that page shouldn't be used anymore. count_threshold is + * initialized to COUNT_MASK which is the maximum. + * + * That error event entry causes cec_add_elem() to return !0 value and thus + * signal to its callers to log the error. + * + * To the question why we've chosen a page and moving elements around with + * memmove(), it is because it is a very simple structure to handle and max data + * movement is 4K which on highly optimized modern CPUs is almost unnoticeable. + * We wanted to avoid the pointer traversal of more complex structures like a + * linked list or some sort of a balancing search tree. + * + * Deleting an element takes O(n) but since it is only a single page, it should + * be fast enough and it shouldn't happen all too often depending on error + * patterns. + */ + +#undef pr_fmt +#define pr_fmt(fmt) "RAS: " fmt + +/* + * We use DECAY_BITS bits of PAGE_SHIFT bits for counting decay, i.e., how long + * elements have stayed in the array without having been accessed again. + */ +#define DECAY_BITS 2 +#define DECAY_MASK ((1ULL << DECAY_BITS) - 1) +#define MAX_ELEMS (PAGE_SIZE / sizeof(u64)) + +/* + * Threshold amount of inserted elements after which we start spring + * cleaning. + */ +#define CLEAN_ELEMS (MAX_ELEMS >> DECAY_BITS) + +/* Bits which count the number of errors happened in this 4K page. */ +#define COUNT_BITS (PAGE_SHIFT - DECAY_BITS) +#define COUNT_MASK ((1ULL << COUNT_BITS) - 1) +#define FULL_COUNT_MASK (PAGE_SIZE - 1) + +/* + * u64: [ 63 ... 12 | DECAY_BITS | COUNT_BITS ] + */ + +#define PFN(e) ((e) >> PAGE_SHIFT) +#define DECAY(e) (((e) >> COUNT_BITS) & DECAY_MASK) +#define COUNT(e) ((unsigned int)(e) & COUNT_MASK) +#define FULL_COUNT(e) ((e) & (PAGE_SIZE - 1)) + +static struct ce_array { + u64 *array; /* container page */ + unsigned int n; /* number of elements in the array */ + + unsigned int decay_count; /* + * number of element insertions/increments + * since the last spring cleaning. + */ + + u64 pfns_poisoned; /* + * number of PFNs which got poisoned. + */ + + u64 ces_entered; /* + * The number of correctable errors + * entered into the collector. + */ + + u64 decays_done; /* + * Times we did spring cleaning. + */ + + union { + struct { + __u32 disabled : 1, /* cmdline disabled */ + __resv : 31; + }; + __u32 flags; + }; +} ce_arr; + +static DEFINE_MUTEX(ce_mutex); +static u64 dfs_pfn; + +/* Amount of errors after which we offline */ +static unsigned int count_threshold = COUNT_MASK; + +/* + * The timer "decays" element count each timer_interval which is 24hrs by + * default. + */ + +#define CEC_TIMER_DEFAULT_INTERVAL 24 * 60 * 60 /* 24 hrs */ +#define CEC_TIMER_MIN_INTERVAL 1 * 60 * 60 /* 1h */ +#define CEC_TIMER_MAX_INTERVAL 30 * 24 * 60 * 60 /* one month */ +static struct timer_list cec_timer; +static u64 timer_interval = CEC_TIMER_DEFAULT_INTERVAL; + +/* + * Decrement decay value. We're using DECAY_BITS bits to denote decay of an + * element in the array. On insertion and any access, it gets reset to max. + */ +static void do_spring_cleaning(struct ce_array *ca) +{ + int i; + + for (i = 0; i < ca->n; i++) { + u8 decay = DECAY(ca->array[i]); + + if (!decay) + continue; + + decay--; + + ca->array[i] &= ~(DECAY_MASK << COUNT_BITS); + ca->array[i] |= (decay << COUNT_BITS); + } + ca->decay_count = 0; + ca->decays_done++; +} + +/* + * @interval in seconds + */ +static void cec_mod_timer(struct timer_list *t, unsigned long interval) +{ + unsigned long iv; + + iv = interval * HZ + jiffies; + + mod_timer(t, round_jiffies(iv)); +} + +static void cec_timer_fn(unsigned long data) +{ + struct ce_array *ca = (struct ce_array *)data; + + do_spring_cleaning(ca); + + cec_mod_timer(&cec_timer, timer_interval); +} + +/* + * @to: index of the smallest element which is >= then @pfn. + * + * Return the index of the pfn if found, otherwise negative value. + */ +static int __find_elem(struct ce_array *ca, u64 pfn, unsigned int *to) +{ + u64 this_pfn; + int min = 0, max = ca->n; + + while (min < max) { + int tmp = (max + min) >> 1; + + this_pfn = PFN(ca->array[tmp]); + + if (this_pfn < pfn) + min = tmp + 1; + else if (this_pfn > pfn) + max = tmp; + else { + min = tmp; + break; + } + } + + if (to) + *to = min; + + this_pfn = PFN(ca->array[min]); + + if (this_pfn == pfn) + return min; + + return -ENOKEY; +} + +static int find_elem(struct ce_array *ca, u64 pfn, unsigned int *to) +{ + WARN_ON(!to); + + if (!ca->n) { + *to = 0; + return -ENOKEY; + } + return __find_elem(ca, pfn, to); +} + +static void del_elem(struct ce_array *ca, int idx) +{ + /* Save us a function call when deleting the last element. */ + if (ca->n - (idx + 1)) + memmove((void *)&ca->array[idx], + (void *)&ca->array[idx + 1], + (ca->n - (idx + 1)) * sizeof(u64)); + + ca->n--; +} + +static u64 del_lru_elem_unlocked(struct ce_array *ca) +{ + unsigned int min = FULL_COUNT_MASK; + int i, min_idx = 0; + + for (i = 0; i < ca->n; i++) { + unsigned int this = FULL_COUNT(ca->array[i]); + + if (min > this) { + min = this; + min_idx = i; + } + } + + del_elem(ca, min_idx); + + return PFN(ca->array[min_idx]); +} + +/* + * We return the 0th pfn in the error case under the assumption that it cannot + * be poisoned and excessive CEs in there are a serious deal anyway. + */ +static u64 __maybe_unused del_lru_elem(void) +{ + struct ce_array *ca = &ce_arr; + u64 pfn; + + if (!ca->n) + return 0; + + mutex_lock(&ce_mutex); + pfn = del_lru_elem_unlocked(ca); + mutex_unlock(&ce_mutex); + + return pfn; +} + + +int cec_add_elem(u64 pfn) +{ + struct ce_array *ca = &ce_arr; + unsigned int to; + int count, ret = 0; + + /* + * We can be called very early on the identify_cpu() path where we are + * not initialized yet. We ignore the error for simplicity. + */ + if (!ce_arr.array || ce_arr.disabled) + return -ENODEV; + + ca->ces_entered++; + + mutex_lock(&ce_mutex); + + if (ca->n == MAX_ELEMS) + WARN_ON(!del_lru_elem_unlocked(ca)); + + ret = find_elem(ca, pfn, &to); + if (ret < 0) { + /* + * Shift range [to-end] to make room for one more element. + */ + memmove((void *)&ca->array[to + 1], + (void *)&ca->array[to], + (ca->n - to) * sizeof(u64)); + + ca->array[to] = (pfn << PAGE_SHIFT) | + (DECAY_MASK << COUNT_BITS) | 1; + + ca->n++; + + ret = 0; + + goto decay; + } + + count = COUNT(ca->array[to]); + + if (count < count_threshold) { + ca->array[to] |= (DECAY_MASK << COUNT_BITS); + ca->array[to]++; + + ret = 0; + } else { + u64 pfn = ca->array[to] >> PAGE_SHIFT; + + if (!pfn_valid(pfn)) { + pr_warn("CEC: Invalid pfn: 0x%llx\n", pfn); + } else { + /* We have reached max count for this page, soft-offline it. */ + pr_err("Soft-offlining pfn: 0x%llx\n", pfn); + memory_failure_queue(pfn, 0, MF_SOFT_OFFLINE); + ca->pfns_poisoned++; + } + + del_elem(ca, to); + + /* + * Return a >0 value to denote that we've reached the offlining + * threshold. + */ + ret = 1; + + goto unlock; + } + +decay: + ca->decay_count++; + + if (ca->decay_count >= CLEAN_ELEMS) + do_spring_cleaning(ca); + +unlock: + mutex_unlock(&ce_mutex); + + return ret; +} + +static int u64_get(void *data, u64 *val) +{ + *val = *(u64 *)data; + + return 0; +} + +static int pfn_set(void *data, u64 val) +{ + *(u64 *)data = val; + + return cec_add_elem(val); +} + +DEFINE_DEBUGFS_ATTRIBUTE(pfn_ops, u64_get, pfn_set, "0x%llx\n"); + +static int decay_interval_set(void *data, u64 val) +{ + *(u64 *)data = val; + + if (val < CEC_TIMER_MIN_INTERVAL) + return -EINVAL; + + if (val > CEC_TIMER_MAX_INTERVAL) + return -EINVAL; + + timer_interval = val; + + cec_mod_timer(&cec_timer, timer_interval); + return 0; +} +DEFINE_DEBUGFS_ATTRIBUTE(decay_interval_ops, u64_get, decay_interval_set, "%lld\n"); + +static int count_threshold_set(void *data, u64 val) +{ + *(u64 *)data = val; + + if (val > COUNT_MASK) + val = COUNT_MASK; + + count_threshold = val; + + return 0; +} +DEFINE_DEBUGFS_ATTRIBUTE(count_threshold_ops, u64_get, count_threshold_set, "%lld\n"); + +static int array_dump(struct seq_file *m, void *v) +{ + struct ce_array *ca = &ce_arr; + u64 prev = 0; + int i; + + mutex_lock(&ce_mutex); + + seq_printf(m, "{ n: %d\n", ca->n); + for (i = 0; i < ca->n; i++) { + u64 this = PFN(ca->array[i]); + + seq_printf(m, " %03d: [%016llx|%03llx]\n", i, this, FULL_COUNT(ca->array[i])); + + WARN_ON(prev > this); + + prev = this; + } + + seq_printf(m, "}\n"); + + seq_printf(m, "Stats:\nCEs: %llu\nofflined pages: %llu\n", + ca->ces_entered, ca->pfns_poisoned); + + seq_printf(m, "Flags: 0x%x\n", ca->flags); + + seq_printf(m, "Timer interval: %lld seconds\n", timer_interval); + seq_printf(m, "Decays: %lld\n", ca->decays_done); + + seq_printf(m, "Action threshold: %d\n", count_threshold); + + mutex_unlock(&ce_mutex); + + return 0; +} + +static int array_open(struct inode *inode, struct file *filp) +{ + return single_open(filp, array_dump, NULL); +} + +static const struct file_operations array_ops = { + .owner = THIS_MODULE, + .open = array_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static int __init create_debugfs_nodes(void) +{ + struct dentry *d, *pfn, *decay, *count, *array; + + d = debugfs_create_dir("cec", ras_debugfs_dir); + if (!d) { + pr_warn("Error creating cec debugfs node!\n"); + return -1; + } + + pfn = debugfs_create_file("pfn", S_IRUSR | S_IWUSR, d, &dfs_pfn, &pfn_ops); + if (!pfn) { + pr_warn("Error creating pfn debugfs node!\n"); + goto err; + } + + array = debugfs_create_file("array", S_IRUSR, d, NULL, &array_ops); + if (!array) { + pr_warn("Error creating array debugfs node!\n"); + goto err; + } + + decay = debugfs_create_file("decay_interval", S_IRUSR | S_IWUSR, d, + &timer_interval, &decay_interval_ops); + if (!decay) { + pr_warn("Error creating decay_interval debugfs node!\n"); + goto err; + } + + count = debugfs_create_file("count_threshold", S_IRUSR | S_IWUSR, d, + &count_threshold, &count_threshold_ops); + if (!decay) { + pr_warn("Error creating count_threshold debugfs node!\n"); + goto err; + } + + + return 0; + +err: + debugfs_remove_recursive(d); + + return 1; +} + +void __init cec_init(void) +{ + if (ce_arr.disabled) + return; + + ce_arr.array = (void *)get_zeroed_page(GFP_KERNEL); + if (!ce_arr.array) { + pr_err("Error allocating CE array page!\n"); + return; + } + + if (create_debugfs_nodes()) + return; + + setup_timer(&cec_timer, cec_timer_fn, (unsigned long)&ce_arr); + cec_mod_timer(&cec_timer, CEC_TIMER_DEFAULT_INTERVAL); + + pr_info("Correctable Errors collector initialized.\n"); +} + +int __init parse_cec_param(char *str) +{ + if (!str) + return 0; + + if (*str == '=') + str++; + + if (!strncmp(str, "cec_disable", 7)) + ce_arr.disabled = 1; + else + return 0; + + return 1; +} diff --git a/drivers/ras/debugfs.c b/drivers/ras/debugfs.c index 0322acf67ea5..501603057dff 100644 --- a/drivers/ras/debugfs.c +++ b/drivers/ras/debugfs.c @@ -1,6 +1,6 @@ #include -static struct dentry *ras_debugfs_dir; +struct dentry *ras_debugfs_dir; static atomic_t trace_count = ATOMIC_INIT(0); diff --git a/drivers/ras/debugfs.h b/drivers/ras/debugfs.h new file mode 100644 index 000000000000..db72e4513191 --- /dev/null +++ b/drivers/ras/debugfs.h @@ -0,0 +1,8 @@ +#ifndef __RAS_DEBUGFS_H__ +#define __RAS_DEBUGFS_H__ + +#include + +extern struct dentry *ras_debugfs_dir; + +#endif /* __RAS_DEBUGFS_H__ */ diff --git a/drivers/ras/ras.c b/drivers/ras/ras.c index b67dd362b7b6..94f8038864b4 100644 --- a/drivers/ras/ras.c +++ b/drivers/ras/ras.c @@ -27,3 +27,14 @@ subsys_initcall(ras_init); EXPORT_TRACEPOINT_SYMBOL_GPL(extlog_mem_event); #endif EXPORT_TRACEPOINT_SYMBOL_GPL(mc_event); + + +int __init parse_ras_param(char *str) +{ +#ifdef CONFIG_RAS_CEC + parse_cec_param(str); +#endif + + return 1; +} +__setup("ras", parse_ras_param); diff --git a/include/linux/ras.h b/include/linux/ras.h index 2aceeafd6fe5..ffb147185e8d 100644 --- a/include/linux/ras.h +++ b/include/linux/ras.h @@ -1,14 +1,25 @@ #ifndef __RAS_H__ #define __RAS_H__ +#include + #ifdef CONFIG_DEBUG_FS int ras_userspace_consumers(void); void ras_debugfs_init(void); int ras_add_daemon_trace(void); #else static inline int ras_userspace_consumers(void) { return 0; } -static inline void ras_debugfs_init(void) { return; } +static inline void ras_debugfs_init(void) { } static inline int ras_add_daemon_trace(void) { return 0; } #endif +#ifdef CONFIG_RAS_CEC +void __init cec_init(void); +int __init parse_cec_param(char *str); +int cec_add_elem(u64 pfn); +#else +static inline void __init cec_init(void) { } +static inline int cec_add_elem(u64 pfn) { return -ENODEV; } #endif + +#endif /* __RAS_H__ */