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Merge tag 'please-pull-ucna' of git://git.kernel.org/pub/scm/linux/ke…
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…rnel/git/ras/ras into x86/ras

Merge RAS updates from Tony Luck:

"Handle all uncorrected error reports in the same way (soft offline
 the page). We used to only do that for SRAO (software recoverable
 action optional) machine checks, but it makes sense to also do it
 for UCNA (UnCorrected No Action) logs found by CMCI or polling."
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Thomas Gleixner committed Nov 21, 2014
2 parents 8dcf32e + fa92c58 commit b9e6df0
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Showing 5 changed files with 78 additions and 16 deletions.
4 changes: 4 additions & 0 deletions arch/x86/include/asm/mce.h
Original file line number Diff line number Diff line change
Expand Up @@ -34,6 +34,10 @@
#define MCI_STATUS_S (1ULL<<56) /* Signaled machine check */
#define MCI_STATUS_AR (1ULL<<55) /* Action required */

/* AMD-specific bits */
#define MCI_STATUS_DEFERRED (1ULL<<44) /* declare an uncorrected error */
#define MCI_STATUS_POISON (1ULL<<43) /* access poisonous data */

/*
* Note that the full MCACOD field of IA32_MCi_STATUS MSR is
* bits 15:0. But bit 12 is the 'F' bit, defined for corrected
Expand Down
4 changes: 3 additions & 1 deletion arch/x86/kernel/cpu/mcheck/mce-internal.h
Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,8 @@

enum severity_level {
MCE_NO_SEVERITY,
MCE_DEFERRED_SEVERITY,
MCE_UCNA_SEVERITY = MCE_DEFERRED_SEVERITY,
MCE_KEEP_SEVERITY,
MCE_SOME_SEVERITY,
MCE_AO_SEVERITY,
Expand All @@ -21,7 +23,7 @@ struct mce_bank {
char attrname[ATTR_LEN]; /* attribute name */
};

int mce_severity(struct mce *a, int tolerant, char **msg);
int mce_severity(struct mce *a, int tolerant, char **msg, bool is_excp);
struct dentry *mce_get_debugfs_dir(void);

extern struct mce_bank *mce_banks;
Expand Down
23 changes: 17 additions & 6 deletions arch/x86/kernel/cpu/mcheck/mce-severity.c
Original file line number Diff line number Diff line change
Expand Up @@ -31,6 +31,7 @@

enum context { IN_KERNEL = 1, IN_USER = 2 };
enum ser { SER_REQUIRED = 1, NO_SER = 2 };
enum exception { EXCP_CONTEXT = 1, NO_EXCP = 2 };

static struct severity {
u64 mask;
Expand All @@ -40,6 +41,7 @@ static struct severity {
unsigned char mcgres;
unsigned char ser;
unsigned char context;
unsigned char excp;
unsigned char covered;
char *msg;
} severities[] = {
Expand All @@ -48,6 +50,8 @@ static struct severity {
#define USER .context = IN_USER
#define SER .ser = SER_REQUIRED
#define NOSER .ser = NO_SER
#define EXCP .excp = EXCP_CONTEXT
#define NOEXCP .excp = NO_EXCP
#define BITCLR(x) .mask = x, .result = 0
#define BITSET(x) .mask = x, .result = x
#define MCGMASK(x, y) .mcgmask = x, .mcgres = y
Expand All @@ -62,7 +66,7 @@ static struct severity {
),
MCESEV(
NO, "Not enabled",
BITCLR(MCI_STATUS_EN)
EXCP, BITCLR(MCI_STATUS_EN)
),
MCESEV(
PANIC, "Processor context corrupt",
Expand All @@ -71,16 +75,20 @@ static struct severity {
/* When MCIP is not set something is very confused */
MCESEV(
PANIC, "MCIP not set in MCA handler",
MCGMASK(MCG_STATUS_MCIP, 0)
EXCP, MCGMASK(MCG_STATUS_MCIP, 0)
),
/* Neither return not error IP -- no chance to recover -> PANIC */
MCESEV(
PANIC, "Neither restart nor error IP",
MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0)
EXCP, MCGMASK(MCG_STATUS_RIPV|MCG_STATUS_EIPV, 0)
),
MCESEV(
PANIC, "In kernel and no restart IP",
KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
EXCP, KERNEL, MCGMASK(MCG_STATUS_RIPV, 0)
),
MCESEV(
DEFERRED, "Deferred error",
NOSER, MASK(MCI_STATUS_UC|MCI_STATUS_DEFERRED|MCI_STATUS_POISON, MCI_STATUS_DEFERRED)
),
MCESEV(
KEEP, "Corrected error",
Expand All @@ -89,7 +97,7 @@ static struct severity {

/* ignore OVER for UCNA */
MCESEV(
KEEP, "Uncorrected no action required",
UCNA, "Uncorrected no action required",
SER, MASK(MCI_UC_SAR, MCI_STATUS_UC)
),
MCESEV(
Expand Down Expand Up @@ -178,8 +186,9 @@ static int error_context(struct mce *m)
return ((m->cs & 3) == 3) ? IN_USER : IN_KERNEL;
}

int mce_severity(struct mce *m, int tolerant, char **msg)
int mce_severity(struct mce *m, int tolerant, char **msg, bool is_excp)
{
enum exception excp = (is_excp ? EXCP_CONTEXT : NO_EXCP);
enum context ctx = error_context(m);
struct severity *s;

Expand All @@ -194,6 +203,8 @@ int mce_severity(struct mce *m, int tolerant, char **msg)
continue;
if (s->context && ctx != s->context)
continue;
if (s->excp && excp != s->excp)
continue;
if (msg)
*msg = s->msg;
s->covered = 1;
Expand Down
60 changes: 54 additions & 6 deletions arch/x86/kernel/cpu/mcheck/mce.c
Original file line number Diff line number Diff line change
Expand Up @@ -575,6 +575,37 @@ 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) {
/*
* coming soon
*/
return false;
} 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);

/*
Expand All @@ -595,6 +626,7 @@ DEFINE_PER_CPU(unsigned, mce_poll_count);
void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)
{
struct mce m;
int severity;
int i;

this_cpu_inc(mce_poll_count);
Expand Down Expand Up @@ -630,6 +662,20 @@ void machine_check_poll(enum mcp_flags flags, mce_banks_t *b)

if (!(flags & MCP_TIMESTAMP))
m.tsc = 0;

severity = mce_severity(&m, mca_cfg.tolerant, NULL, false);

/*
* In the cases where we don't have a valid address after all,
* do not add it into the ring buffer.
*/
if (severity == MCE_DEFERRED_SEVERITY && memory_error(&m)) {
if (m.status & MCI_STATUS_ADDRV) {
mce_ring_add(m.addr >> PAGE_SHIFT);
mce_schedule_work();
}
}

/*
* Don't get the IP here because it's unlikely to
* have anything to do with the actual error location.
Expand Down Expand Up @@ -668,7 +714,8 @@ static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
if (quirk_no_way_out)
quirk_no_way_out(i, m, regs);
}
if (mce_severity(m, mca_cfg.tolerant, msg) >= MCE_PANIC_SEVERITY)
if (mce_severity(m, mca_cfg.tolerant, msg, true) >=
MCE_PANIC_SEVERITY)
ret = 1;
}
return ret;
Expand Down Expand Up @@ -754,7 +801,7 @@ static void mce_reign(void)
for_each_possible_cpu(cpu) {
int severity = mce_severity(&per_cpu(mces_seen, cpu),
mca_cfg.tolerant,
&nmsg);
&nmsg, true);
if (severity > global_worst) {
msg = nmsg;
global_worst = severity;
Expand Down Expand Up @@ -1095,13 +1142,14 @@ void do_machine_check(struct pt_regs *regs, long error_code)
*/
add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);

severity = mce_severity(&m, cfg->tolerant, NULL);
severity = mce_severity(&m, cfg->tolerant, NULL, true);

/*
* When machine check was for corrected handler don't touch,
* unless we're panicing.
* When machine check was for corrected/deferred handler don't
* touch, unless we're panicing.
*/
if (severity == MCE_KEEP_SEVERITY && !no_way_out)
if ((severity == MCE_KEEP_SEVERITY ||
severity == MCE_UCNA_SEVERITY) && !no_way_out)
continue;
__set_bit(i, toclear);
if (severity == MCE_NO_SEVERITY) {
Expand Down
3 changes: 0 additions & 3 deletions drivers/edac/mce_amd.h
Original file line number Diff line number Diff line change
Expand Up @@ -32,9 +32,6 @@
#define R4(x) (((x) >> 4) & 0xf)
#define R4_MSG(x) ((R4(x) < 9) ? rrrr_msgs[R4(x)] : "Wrong R4!")

#define MCI_STATUS_DEFERRED BIT_64(44)
#define MCI_STATUS_POISON BIT_64(43)

extern const char * const pp_msgs[];

enum tt_ids {
Expand Down

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