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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-12-15 14:52:16 -0300
commit8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be (patch)
treee9891aa6c295060d065adffd610c4f49ecf884f3 /arch/x86/kernel/cpu/mcheck
parenta71852147516bc1cb5b0b3cbd13639bfd4022dc8 (diff)
Linux-libre 4.3.2-gnu
Diffstat (limited to 'arch/x86/kernel/cpu/mcheck')
-rw-r--r--arch/x86/kernel/cpu/mcheck/Makefile2
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-apei.c1
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-genpool.c99
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce-internal.h14
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce.c244
-rw-r--r--arch/x86/kernel/cpu/mcheck/mce_intel.c20
-rw-r--r--arch/x86/kernel/cpu/mcheck/p5.c5
-rw-r--r--arch/x86/kernel/cpu/mcheck/winchip.c4
8 files changed, 252 insertions, 137 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/Makefile b/arch/x86/kernel/cpu/mcheck/Makefile
index bb34b03af..a3311c886 100644
--- a/arch/x86/kernel/cpu/mcheck/Makefile
+++ b/arch/x86/kernel/cpu/mcheck/Makefile
@@ -1,4 +1,4 @@
-obj-y = mce.o mce-severity.o
+obj-y = mce.o mce-severity.o mce-genpool.o
obj-$(CONFIG_X86_ANCIENT_MCE) += winchip.o p5.o
obj-$(CONFIG_X86_MCE_INTEL) += mce_intel.o
diff --git a/arch/x86/kernel/cpu/mcheck/mce-apei.c b/arch/x86/kernel/cpu/mcheck/mce-apei.c
index a1aef9533..34c89a3e8 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-apei.c
+++ b/arch/x86/kernel/cpu/mcheck/mce-apei.c
@@ -57,7 +57,6 @@ void apei_mce_report_mem_error(int severity, struct cper_sec_mem_err *mem_err)
m.addr = mem_err->physical_addr;
mce_log(&m);
- mce_notify_irq();
}
EXPORT_SYMBOL_GPL(apei_mce_report_mem_error);
diff --git a/arch/x86/kernel/cpu/mcheck/mce-genpool.c b/arch/x86/kernel/cpu/mcheck/mce-genpool.c
new file mode 100644
index 000000000..0a850100c
--- /dev/null
+++ b/arch/x86/kernel/cpu/mcheck/mce-genpool.c
@@ -0,0 +1,99 @@
+/*
+ * MCE event pool management in MCE context
+ *
+ * Copyright (C) 2015 Intel Corp.
+ * Author: Chen, Gong <gong.chen@linux.intel.com>
+ *
+ * This file is licensed under GPLv2.
+ */
+#include <linux/smp.h>
+#include <linux/mm.h>
+#include <linux/genalloc.h>
+#include <linux/llist.h>
+#include "mce-internal.h"
+
+/*
+ * printk() is not safe in MCE context. This is a lock-less memory allocator
+ * used to save error information organized in a lock-less list.
+ *
+ * This memory pool is only to be used to save MCE records in MCE context.
+ * MCE events are rare, so a fixed size memory pool should be enough. Use
+ * 2 pages to save MCE events for now (~80 MCE records at most).
+ */
+#define MCE_POOLSZ (2 * PAGE_SIZE)
+
+static struct gen_pool *mce_evt_pool;
+static LLIST_HEAD(mce_event_llist);
+static char gen_pool_buf[MCE_POOLSZ];
+
+void mce_gen_pool_process(void)
+{
+ struct llist_node *head;
+ struct mce_evt_llist *node;
+ struct mce *mce;
+
+ head = llist_del_all(&mce_event_llist);
+ if (!head)
+ return;
+
+ head = llist_reverse_order(head);
+ llist_for_each_entry(node, head, llnode) {
+ mce = &node->mce;
+ atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
+ gen_pool_free(mce_evt_pool, (unsigned long)node, sizeof(*node));
+ }
+}
+
+bool mce_gen_pool_empty(void)
+{
+ return llist_empty(&mce_event_llist);
+}
+
+int mce_gen_pool_add(struct mce *mce)
+{
+ struct mce_evt_llist *node;
+
+ if (!mce_evt_pool)
+ return -EINVAL;
+
+ node = (void *)gen_pool_alloc(mce_evt_pool, sizeof(*node));
+ if (!node) {
+ pr_warn_ratelimited("MCE records pool full!\n");
+ return -ENOMEM;
+ }
+
+ memcpy(&node->mce, mce, sizeof(*mce));
+ llist_add(&node->llnode, &mce_event_llist);
+
+ return 0;
+}
+
+static int mce_gen_pool_create(void)
+{
+ struct gen_pool *tmpp;
+ int ret = -ENOMEM;
+
+ tmpp = gen_pool_create(ilog2(sizeof(struct mce_evt_llist)), -1);
+ if (!tmpp)
+ goto out;
+
+ ret = gen_pool_add(tmpp, (unsigned long)gen_pool_buf, MCE_POOLSZ, -1);
+ if (ret) {
+ gen_pool_destroy(tmpp);
+ goto out;
+ }
+
+ mce_evt_pool = tmpp;
+
+out:
+ return ret;
+}
+
+int mce_gen_pool_init(void)
+{
+ /* Just init mce_gen_pool once. */
+ if (mce_evt_pool)
+ return 0;
+
+ return mce_gen_pool_create();
+}
diff --git a/arch/x86/kernel/cpu/mcheck/mce-internal.h b/arch/x86/kernel/cpu/mcheck/mce-internal.h
index fe32074b8..547720efd 100644
--- a/arch/x86/kernel/cpu/mcheck/mce-internal.h
+++ b/arch/x86/kernel/cpu/mcheck/mce-internal.h
@@ -13,6 +13,8 @@ enum severity_level {
MCE_PANIC_SEVERITY,
};
+extern struct atomic_notifier_head x86_mce_decoder_chain;
+
#define ATTR_LEN 16
#define INITIAL_CHECK_INTERVAL 5 * 60 /* 5 minutes */
@@ -24,6 +26,16 @@ struct mce_bank {
char attrname[ATTR_LEN]; /* attribute name */
};
+struct mce_evt_llist {
+ struct llist_node llnode;
+ struct mce mce;
+};
+
+void mce_gen_pool_process(void);
+bool mce_gen_pool_empty(void);
+int mce_gen_pool_add(struct mce *mce);
+int mce_gen_pool_init(void);
+
extern int (*mce_severity)(struct mce *a, int tolerant, char **msg, bool is_excp);
struct dentry *mce_get_debugfs_dir(void);
@@ -67,3 +79,5 @@ static inline int apei_clear_mce(u64 record_id)
return -EINVAL;
}
#endif
+
+void mce_inject_log(struct mce *m);
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index df919ff10..9d014b82a 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -52,11 +52,11 @@
static DEFINE_MUTEX(mce_chrdev_read_mutex);
-#define rcu_dereference_check_mce(p) \
+#define mce_log_get_idx_check(p) \
({ \
- rcu_lockdep_assert(rcu_read_lock_sched_held() || \
- lockdep_is_held(&mce_chrdev_read_mutex), \
- "suspicious rcu_dereference_check_mce() usage"); \
+ 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)); \
})
@@ -110,22 +110,24 @@ DEFINE_PER_CPU(mce_banks_t, mce_poll_banks) = {
*/
mce_banks_t mce_banks_ce_disabled;
-static DEFINE_PER_CPU(struct work_struct, mce_work);
+static struct work_struct mce_work;
+static struct irq_work mce_irq_work;
static void (*quirk_no_way_out)(int bank, struct mce *m, struct pt_regs *regs);
+static int mce_usable_address(struct mce *m);
/*
* CPU/chipset specific EDAC code can register a notifier call here to print
* MCE errors in a human-readable form.
*/
-static ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain);
+ATOMIC_NOTIFIER_HEAD(x86_mce_decoder_chain);
/* Do initial initialization of a struct mce */
void mce_setup(struct mce *m)
{
memset(m, 0, sizeof(struct mce));
m->cpu = m->extcpu = smp_processor_id();
- rdtscll(m->tsc);
+ m->tsc = rdtsc();
/* We hope get_seconds stays lockless */
m->time = get_seconds();
m->cpuvendor = boot_cpu_data.x86_vendor;
@@ -157,12 +159,13 @@ void mce_log(struct mce *mce)
/* Emit the trace record: */
trace_mce_record(mce);
- atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, mce);
+ if (!mce_gen_pool_add(mce))
+ irq_work_queue(&mce_irq_work);
mce->finished = 0;
wmb();
for (;;) {
- entry = rcu_dereference_check_mce(mcelog.next);
+ entry = mce_log_get_idx_check(mcelog.next);
for (;;) {
/*
@@ -196,48 +199,23 @@ void mce_log(struct mce *mce)
set_bit(0, &mce_need_notify);
}
-static void drain_mcelog_buffer(void)
+void mce_inject_log(struct mce *m)
{
- unsigned int next, i, prev = 0;
-
- next = ACCESS_ONCE(mcelog.next);
-
- do {
- struct mce *m;
-
- /* drain what was logged during boot */
- for (i = prev; i < next; i++) {
- unsigned long start = jiffies;
- unsigned retries = 1;
-
- m = &mcelog.entry[i];
-
- while (!m->finished) {
- if (time_after_eq(jiffies, start + 2*retries))
- retries++;
-
- cpu_relax();
-
- if (!m->finished && retries >= 4) {
- pr_err("skipping error being logged currently!\n");
- break;
- }
- }
- smp_rmb();
- atomic_notifier_call_chain(&x86_mce_decoder_chain, 0, m);
- }
-
- memset(mcelog.entry + prev, 0, (next - prev) * sizeof(*m));
- prev = next;
- next = cmpxchg(&mcelog.next, prev, 0);
- } while (next != prev);
+ mutex_lock(&mce_chrdev_read_mutex);
+ mce_log(m);
+ mutex_unlock(&mce_chrdev_read_mutex);
}
+EXPORT_SYMBOL_GPL(mce_inject_log);
+static struct notifier_block mce_srao_nb;
void mce_register_decode_chain(struct notifier_block *nb)
{
+ /* Ensure SRAO notifier has the highest priority in the decode chain. */
+ if (nb != &mce_srao_nb && nb->priority == INT_MAX)
+ nb->priority -= 1;
+
atomic_notifier_chain_register(&x86_mce_decoder_chain, nb);
- drain_mcelog_buffer();
}
EXPORT_SYMBOL_GPL(mce_register_decode_chain);
@@ -461,61 +439,6 @@ static inline void mce_gather_info(struct mce *m, struct pt_regs *regs)
}
}
-/*
- * Simple lockless ring to communicate PFNs from the exception handler with the
- * process context work function. This is vastly simplified because there's
- * only a single reader and a single writer.
- */
-#define MCE_RING_SIZE 16 /* we use one entry less */
-
-struct mce_ring {
- unsigned short start;
- unsigned short end;
- unsigned long ring[MCE_RING_SIZE];
-};
-static DEFINE_PER_CPU(struct mce_ring, mce_ring);
-
-/* Runs with CPU affinity in workqueue */
-static int mce_ring_empty(void)
-{
- struct mce_ring *r = this_cpu_ptr(&mce_ring);
-
- return r->start == r->end;
-}
-
-static int mce_ring_get(unsigned long *pfn)
-{
- struct mce_ring *r;
- int ret = 0;
-
- *pfn = 0;
- get_cpu();
- r = this_cpu_ptr(&mce_ring);
- if (r->start == r->end)
- goto out;
- *pfn = r->ring[r->start];
- r->start = (r->start + 1) % MCE_RING_SIZE;
- ret = 1;
-out:
- put_cpu();
- return ret;
-}
-
-/* Always runs in MCE context with preempt off */
-static int mce_ring_add(unsigned long pfn)
-{
- struct mce_ring *r = this_cpu_ptr(&mce_ring);
- unsigned next;
-
- next = (r->end + 1) % MCE_RING_SIZE;
- if (next == r->start)
- return -1;
- r->ring[r->end] = pfn;
- wmb();
- r->end = next;
- return 0;
-}
-
int mce_available(struct cpuinfo_x86 *c)
{
if (mca_cfg.disabled)
@@ -525,12 +448,10 @@ int mce_available(struct cpuinfo_x86 *c)
static void mce_schedule_work(void)
{
- if (!mce_ring_empty())
- schedule_work(this_cpu_ptr(&mce_work));
+ if (!mce_gen_pool_empty() && keventd_up())
+ schedule_work(&mce_work);
}
-static DEFINE_PER_CPU(struct irq_work, mce_irq_work);
-
static void mce_irq_work_cb(struct irq_work *entry)
{
mce_notify_irq();
@@ -551,8 +472,29 @@ static void mce_report_event(struct pt_regs *regs)
return;
}
- irq_work_queue(this_cpu_ptr(&mce_irq_work));
+ irq_work_queue(&mce_irq_work);
+}
+
+static int srao_decode_notifier(struct notifier_block *nb, unsigned long val,
+ void *data)
+{
+ struct mce *mce = (struct mce *)data;
+ unsigned long pfn;
+
+ if (!mce)
+ return NOTIFY_DONE;
+
+ if (mce->usable_addr && (mce->severity == MCE_AO_SEVERITY)) {
+ pfn = mce->addr >> PAGE_SHIFT;
+ memory_failure(pfn, MCE_VECTOR, 0);
+ }
+
+ return NOTIFY_OK;
}
+static struct notifier_block mce_srao_nb = {
+ .notifier_call = srao_decode_notifier,
+ .priority = INT_MAX,
+};
/*
* Read ADDR and MISC registers.
@@ -672,8 +614,11 @@ bool machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
*/
if (severity == MCE_DEFERRED_SEVERITY && memory_error(&m)) {
if (m.status & MCI_STATUS_ADDRV) {
- mce_ring_add(m.addr >> PAGE_SHIFT);
- mce_schedule_work();
+ m.severity = severity;
+ m.usable_addr = mce_usable_address(&m);
+
+ if (!mce_gen_pool_add(&m))
+ mce_schedule_work();
}
}
@@ -1029,7 +974,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
{
struct mca_config *cfg = &mca_cfg;
struct mce m, *final;
- enum ctx_state prev_state;
int i;
int worst = 0;
int severity;
@@ -1055,7 +999,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
int flags = MF_ACTION_REQUIRED;
int lmce = 0;
- prev_state = ist_enter(regs);
+ ist_enter(regs);
this_cpu_inc(mce_exception_count);
@@ -1143,15 +1087,9 @@ void do_machine_check(struct pt_regs *regs, long error_code)
mce_read_aux(&m, i);
- /*
- * Action optional error. Queue address for later processing.
- * When the ring overflows we just ignore the AO error.
- * RED-PEN add some logging mechanism when
- * usable_address or mce_add_ring fails.
- * RED-PEN don't ignore overflow for mca_cfg.tolerant == 0
- */
- if (severity == MCE_AO_SEVERITY && mce_usable_address(&m))
- mce_ring_add(m.addr >> PAGE_SHIFT);
+ /* assuming valid severity level != 0 */
+ m.severity = severity;
+ m.usable_addr = mce_usable_address(&m);
mce_log(&m);
@@ -1227,7 +1165,7 @@ out:
local_irq_disable();
ist_end_non_atomic();
done:
- ist_exit(regs, prev_state);
+ ist_exit(regs);
}
EXPORT_SYMBOL_GPL(do_machine_check);
@@ -1247,14 +1185,11 @@ int memory_failure(unsigned long pfn, int vector, int flags)
/*
* Action optional processing happens here (picking up
* from the list of faulting pages that do_machine_check()
- * placed into the "ring").
+ * placed into the genpool).
*/
static void mce_process_work(struct work_struct *dummy)
{
- unsigned long pfn;
-
- while (mce_ring_get(&pfn))
- memory_failure(pfn, MCE_VECTOR, 0);
+ mce_gen_pool_process();
}
#ifdef CONFIG_X86_MCE_INTEL
@@ -1678,6 +1613,17 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
}
}
+static void __mcheck_cpu_clear_vendor(struct cpuinfo_x86 *c)
+{
+ switch (c->x86_vendor) {
+ case X86_VENDOR_INTEL:
+ mce_intel_feature_clear(c);
+ break;
+ default:
+ break;
+ }
+}
+
static void mce_start_timer(unsigned int cpu, struct timer_list *t)
{
unsigned long iv = check_interval * HZ;
@@ -1731,13 +1677,36 @@ void mcheck_cpu_init(struct cpuinfo_x86 *c)
return;
}
+ if (mce_gen_pool_init()) {
+ mca_cfg.disabled = true;
+ pr_emerg("Couldn't allocate MCE records pool!\n");
+ return;
+ }
+
machine_check_vector = do_machine_check;
__mcheck_cpu_init_generic();
__mcheck_cpu_init_vendor(c);
__mcheck_cpu_init_timer();
- INIT_WORK(this_cpu_ptr(&mce_work), mce_process_work);
- init_irq_work(this_cpu_ptr(&mce_irq_work), &mce_irq_work_cb);
+}
+
+/*
+ * Called for each booted CPU to clear some machine checks opt-ins
+ */
+void mcheck_cpu_clear(struct cpuinfo_x86 *c)
+{
+ if (mca_cfg.disabled)
+ return;
+
+ if (!mce_available(c))
+ return;
+
+ /*
+ * Possibly to clear general settings generic to x86
+ * __mcheck_cpu_clear_generic(c);
+ */
+ __mcheck_cpu_clear_vendor(c);
+
}
/*
@@ -1784,7 +1753,7 @@ static void collect_tscs(void *data)
{
unsigned long *cpu_tsc = (unsigned long *)data;
- rdtscll(cpu_tsc[smp_processor_id()]);
+ cpu_tsc[smp_processor_id()] = rdtsc();
}
static int mce_apei_read_done;
@@ -1850,7 +1819,7 @@ static ssize_t mce_chrdev_read(struct file *filp, char __user *ubuf,
goto out;
}
- next = rcu_dereference_check_mce(mcelog.next);
+ next = mce_log_get_idx_check(mcelog.next);
/* Only supports full reads right now */
err = -EINVAL;
@@ -2056,8 +2025,12 @@ __setup("mce", mcheck_enable);
int __init mcheck_init(void)
{
mcheck_intel_therm_init();
+ mce_register_decode_chain(&mce_srao_nb);
mcheck_vendor_init_severity();
+ INIT_WORK(&mce_work, mce_process_work);
+ init_irq_work(&mce_irq_work, mce_irq_work_cb);
+
return 0;
}
@@ -2591,5 +2564,20 @@ static int __init mcheck_debugfs_init(void)
return 0;
}
-late_initcall(mcheck_debugfs_init);
+#else
+static int __init mcheck_debugfs_init(void) { return -EINVAL; }
#endif
+
+static int __init mcheck_late_init(void)
+{
+ mcheck_debugfs_init();
+
+ /*
+ * Flush out everything that has been logged during early boot, now that
+ * everything has been initialized (workqueues, decoders, ...).
+ */
+ mce_schedule_work();
+
+ return 0;
+}
+late_initcall(mcheck_late_init);
diff --git a/arch/x86/kernel/cpu/mcheck/mce_intel.c b/arch/x86/kernel/cpu/mcheck/mce_intel.c
index c93c27df9..1e8bb6c94 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_intel.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_intel.c
@@ -251,7 +251,6 @@ static void intel_threshold_interrupt(void)
return;
machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
- mce_notify_irq();
}
/*
@@ -440,7 +439,7 @@ static void intel_init_cmci(void)
cmci_recheck();
}
-void intel_init_lmce(void)
+static void intel_init_lmce(void)
{
u64 val;
@@ -453,9 +452,26 @@ void intel_init_lmce(void)
wrmsrl(MSR_IA32_MCG_EXT_CTL, val | MCG_EXT_CTL_LMCE_EN);
}
+static void intel_clear_lmce(void)
+{
+ u64 val;
+
+ if (!lmce_supported())
+ return;
+
+ rdmsrl(MSR_IA32_MCG_EXT_CTL, val);
+ val &= ~MCG_EXT_CTL_LMCE_EN;
+ wrmsrl(MSR_IA32_MCG_EXT_CTL, val);
+}
+
void mce_intel_feature_init(struct cpuinfo_x86 *c)
{
intel_init_thermal(c);
intel_init_cmci();
intel_init_lmce();
}
+
+void mce_intel_feature_clear(struct cpuinfo_x86 *c)
+{
+ intel_clear_lmce();
+}
diff --git a/arch/x86/kernel/cpu/mcheck/p5.c b/arch/x86/kernel/cpu/mcheck/p5.c
index 737b0ad4e..12402e10a 100644
--- a/arch/x86/kernel/cpu/mcheck/p5.c
+++ b/arch/x86/kernel/cpu/mcheck/p5.c
@@ -19,10 +19,9 @@ int mce_p5_enabled __read_mostly;
/* Machine check handler for Pentium class Intel CPUs: */
static void pentium_machine_check(struct pt_regs *regs, long error_code)
{
- enum ctx_state prev_state;
u32 loaddr, hi, lotype;
- prev_state = ist_enter(regs);
+ ist_enter(regs);
rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
@@ -39,7 +38,7 @@ static void pentium_machine_check(struct pt_regs *regs, long error_code)
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
- ist_exit(regs, prev_state);
+ ist_exit(regs);
}
/* Set up machine check reporting for processors with Intel style MCE: */
diff --git a/arch/x86/kernel/cpu/mcheck/winchip.c b/arch/x86/kernel/cpu/mcheck/winchip.c
index 44f138296..01dd87028 100644
--- a/arch/x86/kernel/cpu/mcheck/winchip.c
+++ b/arch/x86/kernel/cpu/mcheck/winchip.c
@@ -15,12 +15,12 @@
/* Machine check handler for WinChip C6: */
static void winchip_machine_check(struct pt_regs *regs, long error_code)
{
- enum ctx_state prev_state = ist_enter(regs);
+ ist_enter(regs);
printk(KERN_EMERG "CPU0: Machine Check Exception.\n");
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
- ist_exit(regs, prev_state);
+ ist_exit(regs);
}
/* Set up machine check reporting on the Winchip C6 series */