From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754626AbdC1HGo (ORCPT ); Tue, 28 Mar 2017 03:06:44 -0400 Received: from terminus.zytor.com ([65.50.211.136]:43701 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754313AbdC1HGm (ORCPT ); Tue, 28 Mar 2017 03:06:42 -0400 Date: Tue, 28 Mar 2017 00:02:57 -0700 From: tip-bot for Borislav Petkov Message-ID: Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, bp@suse.de, peterz@infradead.org, hpa@zytor.com, tglx@linutronix.de, linux-edac@vger.kernel.org, torvalds@linux-foundation.org Reply-To: hpa@zytor.com, torvalds@linux-foundation.org, linux-edac@vger.kernel.org, tglx@linutronix.de, bp@suse.de, peterz@infradead.org, linux-kernel@vger.kernel.org, mingo@kernel.org In-Reply-To: <20170327093304.10683-5-bp@alien8.de> References: <20170327093304.10683-5-bp@alien8.de> To: linux-tip-commits@vger.kernel.org Subject: [tip:ras/core] RAS: Add a Corrected Errors Collector Git-Commit-ID: 011d8261117249eab97bc86a8e1ac7731e03e319 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 011d8261117249eab97bc86a8e1ac7731e03e319 Gitweb: http://git.kernel.org/tip/011d8261117249eab97bc86a8e1ac7731e03e319 Author: Borislav Petkov AuthorDate: Mon, 27 Mar 2017 11:33:02 +0200 Committer: Ingo Molnar CommitDate: Tue, 28 Mar 2017 08:54:48 +0200 RAS: Add a Corrected Errors Collector Introduce a simple data structure for collecting correctable errors along with accessors. More detailed description in the code itself. The error decoding is done with the decoding chain now and mce_first_notifier() gets to see the error first and the CEC decides whether to log it and then the rest of the chain doesn't hear about it - basically the main reason for the CE collector - or to continue running the notifiers. When the CEC hits the action threshold, it will try to soft-offine the page containing the ECC and then the whole decoding chain gets to see the error. Signed-off-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-edac Link: http://lkml.kernel.org/r/20170327093304.10683-5-bp@alien8.de Signed-off-by: Ingo Molnar --- Documentation/admin-guide/kernel-parameters.txt | 6 + arch/x86/include/asm/mce.h | 9 +- arch/x86/kernel/cpu/mcheck/mce.c | 191 +++++---- arch/x86/ras/Kconfig | 14 + 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 +- 10 files changed, 706 insertions(+), 83 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2ba45ca..927b8b8 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/include/asm/mce.h b/arch/x86/include/asm/mce.h index 0512dcc..c5ae545 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -191,10 +191,11 @@ 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_LOWEST = 0, }; diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c index 8ada093..4a90775 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 @@ -160,47 +161,8 @@ static struct mce_log_buffer mcelog_buf = { void mce_log(struct mce *m) { - unsigned next, entry; - - /* Emit the trace record: */ - trace_mce_record(m); - if (!mce_gen_pool_add(m)) irq_work_queue(&mce_irq_work); - - wmb(); - for (;;) { - entry = mce_log_get_idx_check(mcelog_buf.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_buf.flags); - return; - } - /* Old left over entry. Skip: */ - if (mcelog_buf.entry[entry].finished) { - entry++; - continue; - } - break; - } - smp_rmb(); - next = entry + 1; - if (cmpxchg(&mcelog_buf.next, entry, next) == entry) - break; - } - memcpy(mcelog_buf.entry + entry, m, sizeof(struct mce)); - wmb(); - mcelog_buf.entry[entry].finished = 1; - wmb(); - - set_bit(0, &mce_need_notify); } void mce_inject_log(struct mce *m) @@ -213,6 +175,12 @@ 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) @@ -522,7 +490,6 @@ static void mce_schedule_work(void) static void mce_irq_work_cb(struct irq_work *entry) { - mce_notify_irq(); mce_schedule_work(); } @@ -565,6 +532,111 @@ static int mce_usable_address(struct mce *m) 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; + unsigned int next, entry; + + if (!m) + return NOTIFY_DONE; + + if (cec_add_mce(m)) + return NOTIFY_STOP; + + /* Emit the trace record: */ + trace_mce_record(m); + + wmb(); + for (;;) { + entry = mce_log_get_idx_check(mcelog_buf.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_buf.flags); + return NOTIFY_DONE; + } + /* Old left over entry. Skip: */ + if (mcelog_buf.entry[entry].finished) { + entry++; + continue; + } + break; + } + smp_rmb(); + next = entry + 1; + if (cmpxchg(&mcelog_buf.next, entry, next) == entry) + break; + } + memcpy(mcelog_buf.entry + entry, m, sizeof(struct mce)); + wmb(); + mcelog_buf.entry[entry].finished = 1; + wmb(); + + 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) { @@ -594,11 +666,7 @@ 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) + if (atomic_read(&num_notifiers) > NUM_DEFAULT_NOTIFIERS) return NOTIFY_DONE; /* Don't print when mcelog is running */ @@ -655,37 +723,6 @@ 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); /* @@ -2167,6 +2204,7 @@ __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(); @@ -2716,6 +2754,7 @@ 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/ras/Kconfig b/arch/x86/ras/Kconfig index 0bc60a3..2a2d89d 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/ras/Makefile b/drivers/ras/Makefile index d7f7334..7b26dd3 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 0000000..6aab46d --- /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 0322acf..5016030 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 0000000..db72e45 --- /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 b67dd36..94f8038 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 2aceeaf..ffb1471 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__ */