1 files changed, 387 insertions, 50 deletions

diff --git a/drivers/acpi/apei/erst.c b/drivers/acpi/apei/erst.c
index cf6db6b7662a..631b9477b99c 100644
--- a/drivers/acpi/apei/erst.c
+++ b/drivers/acpi/apei/erst.c
@@ -34,6 +34,7 @@
 #include <linux/cper.h>
 #include <linux/nmi.h>
 #include <linux/hardirq.h>
+#include <linux/pstore.h>
 #include <acpi/apei.h>
 
 #include "apei-internal.h"
@@ -429,6 +430,22 @@ ssize_t erst_get_record_count(void)
 }
 EXPORT_SYMBOL_GPL(erst_get_record_count);
 
+#define ERST_RECORD_ID_CACHE_SIZE_MIN	16
+#define ERST_RECORD_ID_CACHE_SIZE_MAX	1024
+
+struct erst_record_id_cache {
+	struct mutex lock;
+	u64 *entries;
+	int len;
+	int size;
+	int refcount;
+};
+
+static struct erst_record_id_cache erst_record_id_cache = {
+	.lock = __MUTEX_INITIALIZER(erst_record_id_cache.lock),
+	.refcount = 0,
+};
+
 static int __erst_get_next_record_id(u64 *record_id)
 {
 	struct apei_exec_context ctx;
@@ -443,26 +460,179 @@ static int __erst_get_next_record_id(u64 *record_id)
 	return 0;
 }
 
+int erst_get_record_id_begin(int *pos)
+{
+	int rc;
+
+	if (erst_disable)
+		return -ENODEV;
+
+	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
+	if (rc)
+		return rc;
+	erst_record_id_cache.refcount++;
+	mutex_unlock(&erst_record_id_cache.lock);
+
+	*pos = 0;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(erst_get_record_id_begin);
+
+/* erst_record_id_cache.lock must be held by caller */
+static int __erst_record_id_cache_add_one(void)
+{
+	u64 id, prev_id, first_id;
+	int i, rc;
+	u64 *entries;
+	unsigned long flags;
+
+	id = prev_id = first_id = APEI_ERST_INVALID_RECORD_ID;
+retry:
+	raw_spin_lock_irqsave(&erst_lock, flags);
+	rc = __erst_get_next_record_id(&id);
+	raw_spin_unlock_irqrestore(&erst_lock, flags);
+	if (rc == -ENOENT)
+		return 0;
+	if (rc)
+		return rc;
+	if (id == APEI_ERST_INVALID_RECORD_ID)
+		return 0;
+	/* can not skip current ID, or loop back to first ID */
+	if (id == prev_id || id == first_id)
+		return 0;
+	if (first_id == APEI_ERST_INVALID_RECORD_ID)
+		first_id = id;
+	prev_id = id;
+
+	entries = erst_record_id_cache.entries;
+	for (i = 0; i < erst_record_id_cache.len; i++) {
+		if (entries[i] == id)
+			break;
+	}
+	/* record id already in cache, try next */
+	if (i < erst_record_id_cache.len)
+		goto retry;
+	if (erst_record_id_cache.len >= erst_record_id_cache.size) {
+		int new_size, alloc_size;
+		u64 *new_entries;
+
+		new_size = erst_record_id_cache.size * 2;
+		new_size = clamp_val(new_size, ERST_RECORD_ID_CACHE_SIZE_MIN,
+				     ERST_RECORD_ID_CACHE_SIZE_MAX);
+		if (new_size <= erst_record_id_cache.size) {
+			if (printk_ratelimit())
+				pr_warning(FW_WARN ERST_PFX
+					   "too many record ID!\n");
+			return 0;
+		}
+		alloc_size = new_size * sizeof(entries[0]);
+		if (alloc_size < PAGE_SIZE)
+			new_entries = kmalloc(alloc_size, GFP_KERNEL);
+		else
+			new_entries = vmalloc(alloc_size);
+		if (!new_entries)
+			return -ENOMEM;
+		memcpy(new_entries, entries,
+		       erst_record_id_cache.len * sizeof(entries[0]));
+		if (erst_record_id_cache.size < PAGE_SIZE)
+			kfree(entries);
+		else
+			vfree(entries);
+		erst_record_id_cache.entries = entries = new_entries;
+		erst_record_id_cache.size = new_size;
+	}
+	entries[i] = id;
+	erst_record_id_cache.len++;
+
+	return 1;
+}
+
 /*
  * Get the record ID of an existing error record on the persistent
  * storage. If there is no error record on the persistent storage, the
  * returned record_id is APEI_ERST_INVALID_RECORD_ID.
  */
-int erst_get_next_record_id(u64 *record_id)
+int erst_get_record_id_next(int *pos, u64 *record_id)
 {
-	int rc;
-	unsigned long flags;
+	int rc = 0;
+	u64 *entries;
 
 	if (erst_disable)
 		return -ENODEV;
 
-	raw_spin_lock_irqsave(&erst_lock, flags);
-	rc = __erst_get_next_record_id(record_id);
-	raw_spin_unlock_irqrestore(&erst_lock, flags);
+	/* must be enclosed by erst_get_record_id_begin/end */
+	BUG_ON(!erst_record_id_cache.refcount);
+	BUG_ON(*pos < 0 || *pos > erst_record_id_cache.len);
+
+	mutex_lock(&erst_record_id_cache.lock);
+	entries = erst_record_id_cache.entries;
+	for (; *pos < erst_record_id_cache.len; (*pos)++)
+		if (entries[*pos] != APEI_ERST_INVALID_RECORD_ID)
+			break;
+	/* found next record id in cache */
+	if (*pos < erst_record_id_cache.len) {
+		*record_id = entries[*pos];
+		(*pos)++;
+		goto out_unlock;
+	}
+
+	/* Try to add one more record ID to cache */
+	rc = __erst_record_id_cache_add_one();
+	if (rc < 0)
+		goto out_unlock;
+	/* successfully add one new ID */
+	if (rc == 1) {
+		*record_id = erst_record_id_cache.entries[*pos];
+		(*pos)++;
+		rc = 0;
+	} else {
+		*pos = -1;
+		*record_id = APEI_ERST_INVALID_RECORD_ID;
+	}
+out_unlock:
+	mutex_unlock(&erst_record_id_cache.lock);
 
 	return rc;
 }
-EXPORT_SYMBOL_GPL(erst_get_next_record_id);
+EXPORT_SYMBOL_GPL(erst_get_record_id_next);
+
+/* erst_record_id_cache.lock must be held by caller */
+static void __erst_record_id_cache_compact(void)
+{
+	int i, wpos = 0;
+	u64 *entries;
+
+	if (erst_record_id_cache.refcount)
+		return;
+
+	entries = erst_record_id_cache.entries;
+	for (i = 0; i < erst_record_id_cache.len; i++) {
+		if (entries[i] == APEI_ERST_INVALID_RECORD_ID)
+			continue;
+		if (wpos != i)
+			memcpy(&entries[wpos], &entries[i], sizeof(entries[i]));
+		wpos++;
+	}
+	erst_record_id_cache.len = wpos;
+}
+
+void erst_get_record_id_end(void)
+{
+	/*
+	 * erst_disable != 0 should be detected by invoker via the
+	 * return value of erst_get_record_id_begin/next, so this
+	 * function should not be called for erst_disable != 0.
+	 */
+	BUG_ON(erst_disable);
+
+	mutex_lock(&erst_record_id_cache.lock);
+	erst_record_id_cache.refcount--;
+	BUG_ON(erst_record_id_cache.refcount < 0);
+	__erst_record_id_cache_compact();
+	mutex_unlock(&erst_record_id_cache.lock);
+}
+EXPORT_SYMBOL_GPL(erst_get_record_id_end);
 
 static int __erst_write_to_storage(u64 offset)
 {
@@ -472,7 +642,7 @@ static int __erst_write_to_storage(u64 offset)
 	int rc;
 
 	erst_exec_ctx_init(&ctx);
-	rc = apei_exec_run(&ctx, ACPI_ERST_BEGIN_WRITE);
+	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_WRITE);
 	if (rc)
 		return rc;
 	apei_exec_ctx_set_input(&ctx, offset);
@@ -496,7 +666,7 @@ static int __erst_write_to_storage(u64 offset)
 	if (rc)
 		return rc;
 	val = apei_exec_ctx_get_output(&ctx);
-	rc = apei_exec_run(&ctx, ACPI_ERST_END);
+	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 	if (rc)
 		return rc;
 
@@ -511,7 +681,7 @@ static int __erst_read_from_storage(u64 record_id, u64 offset)
 	int rc;
 
 	erst_exec_ctx_init(&ctx);
-	rc = apei_exec_run(&ctx, ACPI_ERST_BEGIN_READ);
+	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_READ);
 	if (rc)
 		return rc;
 	apei_exec_ctx_set_input(&ctx, offset);
@@ -539,7 +709,7 @@ static int __erst_read_from_storage(u64 record_id, u64 offset)
 	if (rc)
 		return rc;
 	val = apei_exec_ctx_get_output(&ctx);
-	rc = apei_exec_run(&ctx, ACPI_ERST_END);
+	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 	if (rc)
 		return rc;
 
@@ -554,7 +724,7 @@ static int __erst_clear_from_storage(u64 record_id)
 	int rc;
 
 	erst_exec_ctx_init(&ctx);
-	rc = apei_exec_run(&ctx, ACPI_ERST_BEGIN_CLEAR);
+	rc = apei_exec_run_optional(&ctx, ACPI_ERST_BEGIN_CLEAR);
 	if (rc)
 		return rc;
 	apei_exec_ctx_set_input(&ctx, record_id);
@@ -578,7 +748,7 @@ static int __erst_clear_from_storage(u64 record_id)
 	if (rc)
 		return rc;
 	val = apei_exec_ctx_get_output(&ctx);
-	rc = apei_exec_run(&ctx, ACPI_ERST_END);
+	rc = apei_exec_run_optional(&ctx, ACPI_ERST_END);
 	if (rc)
 		return rc;
 
@@ -703,56 +873,34 @@ ssize_t erst_read(u64 record_id, struct cper_record_header *record,
 }
 EXPORT_SYMBOL_GPL(erst_read);
 
-/*
- * If return value > buflen, the buffer size is not big enough,
- * else if return value = 0, there is no more record to read,
- * else if return value < 0, something goes wrong,
- * else everything is OK, and return value is record length
- */
-ssize_t erst_read_next(struct cper_record_header *record, size_t buflen)
-{
-	int rc;
-	ssize_t len;
-	unsigned long flags;
-	u64 record_id;
-
-	if (erst_disable)
-		return -ENODEV;
-
-	raw_spin_lock_irqsave(&erst_lock, flags);
-	rc = __erst_get_next_record_id(&record_id);
-	if (rc) {
-		raw_spin_unlock_irqrestore(&erst_lock, flags);
-		return rc;
-	}
-	/* no more record */
-	if (record_id == APEI_ERST_INVALID_RECORD_ID) {
-		raw_spin_unlock_irqrestore(&erst_lock, flags);
-		return 0;
-	}
-
-	len = __erst_read(record_id, record, buflen);
-	raw_spin_unlock_irqrestore(&erst_lock, flags);
-
-	return len;
-}
-EXPORT_SYMBOL_GPL(erst_read_next);
-
 int erst_clear(u64 record_id)
 {
-	int rc;
+	int rc, i;
 	unsigned long flags;
+	u64 *entries;
 
 	if (erst_disable)
 		return -ENODEV;
 
+	rc = mutex_lock_interruptible(&erst_record_id_cache.lock);
+	if (rc)
+		return rc;
 	raw_spin_lock_irqsave(&erst_lock, flags);
 	if (erst_erange.attr & ERST_RANGE_NVRAM)
 		rc = __erst_clear_from_nvram(record_id);
 	else
 		rc = __erst_clear_from_storage(record_id);
 	raw_spin_unlock_irqrestore(&erst_lock, flags);
-
+	if (rc)
+		goto out;
+	entries = erst_record_id_cache.entries;
+	for (i = 0; i < erst_record_id_cache.len; i++) {
+		if (entries[i] == record_id)
+			entries[i] = APEI_ERST_INVALID_RECORD_ID;
+	}
+	__erst_record_id_cache_compact();
+out:
+	mutex_unlock(&erst_record_id_cache.lock);
 	return rc;
 }
 EXPORT_SYMBOL_GPL(erst_clear);
@@ -781,6 +929,182 @@ static int erst_check_table(struct acpi_table_erst *erst_tab)
 	return 0;
 }
 
+static int erst_open_pstore(struct pstore_info *psi);
+static int erst_close_pstore(struct pstore_info *psi);
+static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
+			   struct timespec *time, char **buf,
+			   struct pstore_info *psi);
+static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part,
+		       size_t size, struct pstore_info *psi);
+static int erst_clearer(enum pstore_type_id type, u64 id,
+			struct pstore_info *psi);
+
+static struct pstore_info erst_info = {
+	.owner		= THIS_MODULE,
+	.name		= "erst",
+	.open		= erst_open_pstore,
+	.close		= erst_close_pstore,
+	.read		= erst_reader,
+	.write		= erst_writer,
+	.erase		= erst_clearer
+};
+
+#define CPER_CREATOR_PSTORE						\
+	UUID_LE(0x75a574e3, 0x5052, 0x4b29, 0x8a, 0x8e, 0xbe, 0x2c,	\
+		0x64, 0x90, 0xb8, 0x9d)
+#define CPER_SECTION_TYPE_DMESG						\
+	UUID_LE(0xc197e04e, 0xd545, 0x4a70, 0x9c, 0x17, 0xa5, 0x54,	\
+		0x94, 0x19, 0xeb, 0x12)
+#define CPER_SECTION_TYPE_MCE						\
+	UUID_LE(0xfe08ffbe, 0x95e4, 0x4be7, 0xbc, 0x73, 0x40, 0x96,	\
+		0x04, 0x4a, 0x38, 0xfc)
+
+struct cper_pstore_record {
+	struct cper_record_header hdr;
+	struct cper_section_descriptor sec_hdr;
+	char data[];
+} __packed;
+
+static int reader_pos;
+
+static int erst_open_pstore(struct pstore_info *psi)
+{
+	int rc;
+
+	if (erst_disable)
+		return -ENODEV;
+
+	rc = erst_get_record_id_begin(&reader_pos);
+
+	return rc;
+}
+
+static int erst_close_pstore(struct pstore_info *psi)
+{
+	erst_get_record_id_end();
+
+	return 0;
+}
+
+static ssize_t erst_reader(u64 *id, enum pstore_type_id *type,
+			   struct timespec *time, char **buf,
+			   struct pstore_info *psi)
+{
+	int rc;
+	ssize_t len = 0;
+	u64 record_id;
+	struct cper_pstore_record *rcd;
+	size_t rcd_len = sizeof(*rcd) + erst_info.bufsize;
+
+	if (erst_disable)
+		return -ENODEV;
+
+	rcd = kmalloc(rcd_len, GFP_KERNEL);
+	if (!rcd) {
+		rc = -ENOMEM;
+		goto out;
+	}
+skip:
+	rc = erst_get_record_id_next(&reader_pos, &record_id);
+	if (rc)
+		goto out;
+
+	/* no more record */
+	if (record_id == APEI_ERST_INVALID_RECORD_ID) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+	len = erst_read(record_id, &rcd->hdr, rcd_len);
+	/* The record may be cleared by others, try read next record */
+	if (len == -ENOENT)
+		goto skip;
+	else if (len < sizeof(*rcd)) {
+		rc = -EIO;
+		goto out;
+	}
+	if (uuid_le_cmp(rcd->hdr.creator_id, CPER_CREATOR_PSTORE) != 0)
+		goto skip;
+
+	*buf = kmalloc(len, GFP_KERNEL);
+	if (*buf == NULL) {
+		rc = -ENOMEM;
+		goto out;
+	}
+	memcpy(*buf, rcd->data, len - sizeof(*rcd));
+	*id = record_id;
+	if (uuid_le_cmp(rcd->sec_hdr.section_type,
+			CPER_SECTION_TYPE_DMESG) == 0)
+		*type = PSTORE_TYPE_DMESG;
+	else if (uuid_le_cmp(rcd->sec_hdr.section_type,
+			     CPER_SECTION_TYPE_MCE) == 0)
+		*type = PSTORE_TYPE_MCE;
+	else
+		*type = PSTORE_TYPE_UNKNOWN;
+
+	if (rcd->hdr.validation_bits & CPER_VALID_TIMESTAMP)
+		time->tv_sec = rcd->hdr.timestamp;
+	else
+		time->tv_sec = 0;
+	time->tv_nsec = 0;
+
+out:
+	kfree(rcd);
+	return (rc < 0) ? rc : (len - sizeof(*rcd));
+}
+
+static int erst_writer(enum pstore_type_id type, u64 *id, unsigned int part,
+		       size_t size, struct pstore_info *psi)
+{
+	struct cper_pstore_record *rcd = (struct cper_pstore_record *)
+					(erst_info.buf - sizeof(*rcd));
+	int ret;
+
+	memset(rcd, 0, sizeof(*rcd));
+	memcpy(rcd->hdr.signature, CPER_SIG_RECORD, CPER_SIG_SIZE);
+	rcd->hdr.revision = CPER_RECORD_REV;
+	rcd->hdr.signature_end = CPER_SIG_END;
+	rcd->hdr.section_count = 1;
+	rcd->hdr.error_severity = CPER_SEV_FATAL;
+	/* timestamp valid. platform_id, partition_id are invalid */
+	rcd->hdr.validation_bits = CPER_VALID_TIMESTAMP;
+	rcd->hdr.timestamp = get_seconds();
+	rcd->hdr.record_length = sizeof(*rcd) + size;
+	rcd->hdr.creator_id = CPER_CREATOR_PSTORE;
+	rcd->hdr.notification_type = CPER_NOTIFY_MCE;
+	rcd->hdr.record_id = cper_next_record_id();
+	rcd->hdr.flags = CPER_HW_ERROR_FLAGS_PREVERR;
+
+	rcd->sec_hdr.section_offset = sizeof(*rcd);
+	rcd->sec_hdr.section_length = size;
+	rcd->sec_hdr.revision = CPER_SEC_REV;
+	/* fru_id and fru_text is invalid */
+	rcd->sec_hdr.validation_bits = 0;
+	rcd->sec_hdr.flags = CPER_SEC_PRIMARY;
+	switch (type) {
+	case PSTORE_TYPE_DMESG:
+		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_DMESG;
+		break;
+	case PSTORE_TYPE_MCE:
+		rcd->sec_hdr.section_type = CPER_SECTION_TYPE_MCE;
+		break;
+	default:
+		return -EINVAL;
+	}
+	rcd->sec_hdr.section_severity = CPER_SEV_FATAL;
+
+	ret = erst_write(&rcd->hdr);
+	*id = rcd->hdr.record_id;
+
+	return ret;
+}
+
+static int erst_clearer(enum pstore_type_id type, u64 id,
+			struct pstore_info *psi)
+{
+	return erst_clear(id);
+}
+
 static int __init erst_init(void)
 {
 	int rc = 0;
@@ -788,6 +1112,7 @@ static int __init erst_init(void)
 	struct apei_exec_context ctx;
 	struct apei_resources erst_resources;
 	struct resource *r;
+	char *buf;
 
 	if (acpi_disabled)
 		goto err;
@@ -854,6 +1179,18 @@ static int __init erst_init(void)
 	if (!erst_erange.vaddr)
 		goto err_release_erange;
 
+	buf = kmalloc(erst_erange.size, GFP_KERNEL);
+	spin_lock_init(&erst_info.buf_lock);
+	if (buf) {
+		erst_info.buf = buf + sizeof(struct cper_pstore_record);
+		erst_info.bufsize = erst_erange.size -
+				    sizeof(struct cper_pstore_record);
+		if (pstore_register(&erst_info)) {
+			pr_info(ERST_PFX "Could not register with persistent store\n");
+			kfree(buf);
+		}
+	}
+
 	pr_info(ERST_PFX
 	"Error Record Serialization Table (ERST) support is initialized.\n");