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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Merge tag 'please-pull-ucna' of git://git.kernel.org/pub/scm/linux/kernel/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."

arch/x86/include/asm/mce.h

@@ -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

arch/x86/kernel/cpu/mcheck/mce-internal.h

@@ -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,
@@ -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;

arch/x86/kernel/cpu/mcheck/mce-severity.c

@@ -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;
@@ -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[] = {
@@ -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
@@ -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",
@@ -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",
@@ -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(
@@ -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;
 
@@ -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;

arch/x86/kernel/cpu/mcheck/mce.c

@@ -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);
 
 /*
@@ -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);
@@ -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.
@@ -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;
@@ -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;
@@ -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,
+		 * When machine check was for corrected/deferred handler don't
-		 * unless we're panicing.
+		 * 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) {

drivers/edac/mce_amd.h

@@ -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 {