1 files changed, 139 insertions, 134 deletions

diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 6e4a047..9e314bc 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -164,17 +164,48 @@ static void default_deferred_error_interrupt(void)
 }
 void (*deferred_error_int_vector)(void) = default_deferred_error_interrupt;
 
-static void get_smca_bank_info(unsigned int bank)
+static void smca_configure(unsigned int bank, unsigned int cpu)
 {
-	unsigned int i, hwid_mcatype, cpu = smp_processor_id();
+	unsigned int i, hwid_mcatype;
 	struct smca_hwid *s_hwid;
-	u32 high, instance_id;
+	u32 high, low;
+	u32 smca_config = MSR_AMD64_SMCA_MCx_CONFIG(bank);
+
+	/* Set appropriate bits in MCA_CONFIG */
+	if (!rdmsr_safe(smca_config, &low, &high)) {
+		/*
+		 * OS is required to set the MCAX bit to acknowledge that it is
+		 * now using the new MSR ranges and new registers under each
+		 * bank. It also means that the OS will configure deferred
+		 * errors in the new MCx_CONFIG register. If the bit is not set,
+		 * uncorrectable errors will cause a system panic.
+		 *
+		 * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of the MSR.)
+		 */
+		high |= BIT(0);
+
+		/*
+		 * SMCA sets the Deferred Error Interrupt type per bank.
+		 *
+		 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
+		 * if the DeferredIntType bit field is available.
+		 *
+		 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
+		 * high portion of the MSR). OS should set this to 0x1 to enable
+		 * APIC based interrupt. First, check that no interrupt has been
+		 * set.
+		 */
+		if ((low & BIT(5)) && !((high >> 5) & 0x3))
+			high |= BIT(5);
+
+		wrmsr(smca_config, low, high);
+	}
 
 	/* Collect bank_info using CPU 0 for now. */
 	if (cpu)
 		return;
 
-	if (rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_IPID(bank), &instance_id, &high)) {
+	if (rdmsr_safe_on_cpu(cpu, MSR_AMD64_SMCA_MCx_IPID(bank), &low, &high)) {
 		pr_warn("Failed to read MCA_IPID for bank %d\n", bank);
 		return;
 	}
@@ -191,7 +222,7 @@ static void get_smca_bank_info(unsigned int bank)
 			     smca_get_name(s_hwid->bank_type));
 
 			smca_banks[bank].hwid = s_hwid;
-			smca_banks[bank].id = instance_id;
+			smca_banks[bank].id = low;
 			smca_banks[bank].sysfs_id = s_hwid->count++;
 			break;
 		}
@@ -433,7 +464,7 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
 			int offset, u32 misc_high)
 {
 	unsigned int cpu = smp_processor_id();
-	u32 smca_low, smca_high, smca_addr;
+	u32 smca_low, smca_high;
 	struct threshold_block b;
 	int new;
 
@@ -457,51 +488,6 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
 		goto set_offset;
 	}
 
-	smca_addr = MSR_AMD64_SMCA_MCx_CONFIG(bank);
-
-	if (!rdmsr_safe(smca_addr, &smca_low, &smca_high)) {
-		/*
-		 * OS is required to set the MCAX bit to acknowledge that it is
-		 * now using the new MSR ranges and new registers under each
-		 * bank. It also means that the OS will configure deferred
-		 * errors in the new MCx_CONFIG register. If the bit is not set,
-		 * uncorrectable errors will cause a system panic.
-		 *
-		 * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of the MSR.)
-		 */
-		smca_high |= BIT(0);
-
-		/*
-		 * SMCA logs Deferred Error information in MCA_DE{STAT,ADDR}
-		 * registers with the option of additionally logging to
-		 * MCA_{STATUS,ADDR} if MCA_CONFIG[LogDeferredInMcaStat] is set.
-		 *
-		 * This bit is usually set by BIOS to retain the old behavior
-		 * for OSes that don't use the new registers. Linux supports the
-		 * new registers so let's disable that additional logging here.
-		 *
-		 * MCA_CONFIG[LogDeferredInMcaStat] is bit 34 (bit 2 in the high
-		 * portion of the MSR).
-		 */
-		smca_high &= ~BIT(2);
-
-		/*
-		 * SMCA sets the Deferred Error Interrupt type per bank.
-		 *
-		 * MCA_CONFIG[DeferredIntTypeSupported] is bit 5, and tells us
-		 * if the DeferredIntType bit field is available.
-		 *
-		 * MCA_CONFIG[DeferredIntType] is bits [38:37] ([6:5] in the
-		 * high portion of the MSR). OS should set this to 0x1 to enable
-		 * APIC based interrupt. First, check that no interrupt has been
-		 * set.
-		 */
-		if ((smca_low & BIT(5)) && !((smca_high >> 5) & 0x3))
-			smca_high |= BIT(5);
-
-		wrmsr(smca_addr, smca_low, smca_high);
-	}
-
 	/* Gather LVT offset for thresholding: */
 	if (rdmsr_safe(MSR_CU_DEF_ERR, &smca_low, &smca_high))
 		goto out;
@@ -530,7 +516,7 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 
 	for (bank = 0; bank < mca_cfg.banks; ++bank) {
 		if (mce_flags.smca)
-			get_smca_bank_info(bank);
+			smca_configure(bank, cpu);
 
 		for (block = 0; block < NR_BLOCKS; ++block) {
 			address = get_block_address(cpu, address, low, high, bank, block);
@@ -755,37 +741,19 @@ out_err:
 }
 EXPORT_SYMBOL_GPL(umc_normaddr_to_sysaddr);
 
-static void
-__log_error(unsigned int bank, bool deferred_err, bool threshold_err, u64 misc)
+static void __log_error(unsigned int bank, u64 status, u64 addr, u64 misc)
 {
-	u32 msr_status = msr_ops.status(bank);
-	u32 msr_addr = msr_ops.addr(bank);
 	struct mce m;
-	u64 status;
-
-	WARN_ON_ONCE(deferred_err && threshold_err);
-
-	if (deferred_err && mce_flags.smca) {
-		msr_status = MSR_AMD64_SMCA_MCx_DESTAT(bank);
-		msr_addr = MSR_AMD64_SMCA_MCx_DEADDR(bank);
-	}
-
-	rdmsrl(msr_status, status);
-
-	if (!(status & MCI_STATUS_VAL))
-		return;
 
 	mce_setup(&m);
 
 	m.status = status;
+	m.misc   = misc;
 	m.bank   = bank;
 	m.tsc	 = rdtsc();
 
-	if (threshold_err)
-		m.misc = misc;
-
 	if (m.status & MCI_STATUS_ADDRV) {
-		rdmsrl(msr_addr, m.addr);
+		m.addr = addr;
 
 		/*
 		 * Extract [55:<lsb>] where lsb is the least significant
@@ -806,8 +774,6 @@ __log_error(unsigned int bank, bool deferred_err, bool threshold_err, u64 misc)
 	}
 
 	mce_log(&m);
-
-	wrmsrl(msr_status, 0);
 }
 
 static inline void __smp_deferred_error_interrupt(void)
@@ -832,87 +798,126 @@ asmlinkage __visible void __irq_entry smp_trace_deferred_error_interrupt(void)
 	exiting_ack_irq();
 }
 
-/* APIC interrupt handler for deferred errors */
-static void amd_deferred_error_interrupt(void)
+/*
+ * Returns true if the logged error is deferred. False, otherwise.
+ */
+static inline bool
+_log_error_bank(unsigned int bank, u32 msr_stat, u32 msr_addr, u64 misc)
 {
-	unsigned int bank;
-	u32 msr_status;
-	u64 status;
+	u64 status, addr = 0;
 
-	for (bank = 0; bank < mca_cfg.banks; ++bank) {
-		msr_status = (mce_flags.smca) ? MSR_AMD64_SMCA_MCx_DESTAT(bank)
-					      : msr_ops.status(bank);
+	rdmsrl(msr_stat, status);
+	if (!(status & MCI_STATUS_VAL))
+		return false;
 
-		rdmsrl(msr_status, status);
+	if (status & MCI_STATUS_ADDRV)
+		rdmsrl(msr_addr, addr);
 
-		if (!(status & MCI_STATUS_VAL) ||
-		    !(status & MCI_STATUS_DEFERRED))
-			continue;
+	__log_error(bank, status, addr, misc);
 
-		__log_error(bank, true, false, 0);
-		break;
-	}
+	wrmsrl(msr_stat, 0);
+
+	return status & MCI_STATUS_DEFERRED;
 }
 
 /*
- * APIC Interrupt Handler
+ * We have three scenarios for checking for Deferred errors:
+ *
+ * 1) Non-SMCA systems check MCA_STATUS and log error if found.
+ * 2) SMCA systems check MCA_STATUS. If error is found then log it and also
+ *    clear MCA_DESTAT.
+ * 3) SMCA systems check MCA_DESTAT, if error was not found in MCA_STATUS, and
+ *    log it.
  */
+static void log_error_deferred(unsigned int bank)
+{
+	bool defrd;
 
-/*
- * threshold interrupt handler will service THRESHOLD_APIC_VECTOR.
- * the interrupt goes off when error_count reaches threshold_limit.
- * the handler will simply log mcelog w/ software defined bank number.
- */
+	defrd = _log_error_bank(bank, msr_ops.status(bank),
+					msr_ops.addr(bank), 0);
 
-static void amd_threshold_interrupt(void)
+	if (!mce_flags.smca)
+		return;
+
+	/* Clear MCA_DESTAT if we logged the deferred error from MCA_STATUS. */
+	if (defrd) {
+		wrmsrl(MSR_AMD64_SMCA_MCx_DESTAT(bank), 0);
+		return;
+	}
+
+	/*
+	 * Only deferred errors are logged in MCA_DE{STAT,ADDR} so just check
+	 * for a valid error.
+	 */
+	_log_error_bank(bank, MSR_AMD64_SMCA_MCx_DESTAT(bank),
+			      MSR_AMD64_SMCA_MCx_DEADDR(bank), 0);
+}
+
+/* APIC interrupt handler for deferred errors */
+static void amd_deferred_error_interrupt(void)
 {
-	u32 low = 0, high = 0, address = 0;
-	unsigned int bank, block, cpu = smp_processor_id();
-	struct thresh_restart tr;
+	unsigned int bank;
 
-	/* assume first bank caused it */
-	for (bank = 0; bank < mca_cfg.banks; ++bank) {
-		if (!(per_cpu(bank_map, cpu) & (1 << bank)))
-			continue;
-		for (block = 0; block < NR_BLOCKS; ++block) {
-			address = get_block_address(cpu, address, low, high, bank, block);
-			if (!address)
-				break;
+	for (bank = 0; bank < mca_cfg.banks; ++bank)
+		log_error_deferred(bank);
+}
 
-			if (rdmsr_safe(address, &low, &high))
-				break;
+static void log_error_thresholding(unsigned int bank, u64 misc)
+{
+	_log_error_bank(bank, msr_ops.status(bank), msr_ops.addr(bank), misc);
+}
 
-			if (!(high & MASK_VALID_HI)) {
-				if (block)
-					continue;
-				else
-					break;
-			}
+static void log_and_reset_block(struct threshold_block *block)
+{
+	struct thresh_restart tr;
+	u32 low = 0, high = 0;
 
-			if (!(high & MASK_CNTP_HI)  ||
-			     (high & MASK_LOCKED_HI))
-				continue;
+	if (!block)
+		return;
 
-			/*
-			 * Log the machine check that caused the threshold
-			 * event.
-			 */
-			if (high & MASK_OVERFLOW_HI)
-				goto log;
-		}
-	}
-	return;
+	if (rdmsr_safe(block->address, &low, &high))
+		return;
+
+	if (!(high & MASK_OVERFLOW_HI))
+		return;
 
-log:
-	__log_error(bank, false, true, ((u64)high << 32) | low);
+	/* Log the MCE which caused the threshold event. */
+	log_error_thresholding(block->bank, ((u64)high << 32) | low);
 
 	/* Reset threshold block after logging error. */
 	memset(&tr, 0, sizeof(tr));
-	tr.b = &per_cpu(threshold_banks, cpu)[bank]->blocks[block];
+	tr.b = block;
 	threshold_restart_bank(&tr);
 }
 
 /*
+ * Threshold interrupt handler will service THRESHOLD_APIC_VECTOR. The interrupt
+ * goes off when error_count reaches threshold_limit.
+ */
+static void amd_threshold_interrupt(void)
+{
+	struct threshold_block *first_block = NULL, *block = NULL, *tmp = NULL;
+	unsigned int bank, cpu = smp_processor_id();
+
+	for (bank = 0; bank < mca_cfg.banks; ++bank) {
+		if (!(per_cpu(bank_map, cpu) & (1 << bank)))
+			continue;
+
+		first_block = per_cpu(threshold_banks, cpu)[bank]->blocks;
+		if (!first_block)
+			continue;
+
+		/*
+		 * The first block is also the head of the list. Check it first
+		 * before iterating over the rest.
+		 */
+		log_and_reset_block(first_block);
+		list_for_each_entry_safe(block, tmp, &first_block->miscj, miscj)
+			log_and_reset_block(block);
+	}
+}
+
+/*
  * Sysfs Interface
  */
 
@@ -1202,7 +1207,7 @@ static int threshold_create_bank(unsigned int cpu, unsigned int bank)
 				goto out;
 
 			per_cpu(threshold_banks, cpu)[bank] = b;
-			atomic_inc(&b->cpus);
+			refcount_inc(&b->cpus);
 
 			err = __threshold_add_blocks(b);
 
@@ -1225,7 +1230,7 @@ static int threshold_create_bank(unsigned int cpu, unsigned int bank)
 	per_cpu(threshold_banks, cpu)[bank] = b;
 
 	if (is_shared_bank(bank)) {
-		atomic_set(&b->cpus, 1);
+		refcount_set(&b->cpus, 1);
 
 		/* nb is already initialized, see above */
 		if (nb) {
@@ -1289,7 +1294,7 @@ static void threshold_remove_bank(unsigned int cpu, int bank)
 		goto free_out;
 
 	if (is_shared_bank(bank)) {
-		if (!atomic_dec_and_test(&b->cpus)) {
+		if (!refcount_dec_and_test(&b->cpus)) {
 			__threshold_remove_blocks(b);
 			per_cpu(threshold_banks, cpu)[bank] = NULL;
 			return;