diff options
Diffstat (limited to 'drivers/acpi/apei/erst-dbg.c')
| -rw-r--r-- | drivers/acpi/apei/erst-dbg.c | 41 |
1 files changed, 36 insertions, 5 deletions
diff --git a/drivers/acpi/apei/erst-dbg.c b/drivers/acpi/apei/erst-dbg.c index de73caf3ceb..04ab5c9d3ce 100644 --- a/drivers/acpi/apei/erst-dbg.c +++ b/drivers/acpi/apei/erst-dbg.c @@ -33,7 +33,7 @@ #define ERST_DBG_PFX "ERST DBG: " -#define ERST_DBG_RECORD_LEN_MAX 4096 +#define ERST_DBG_RECORD_LEN_MAX 0x4000 static void *erst_dbg_buf; static unsigned int erst_dbg_buf_len; @@ -43,12 +43,27 @@ static DEFINE_MUTEX(erst_dbg_mutex); static int erst_dbg_open(struct inode *inode, struct file *file) { + int rc, *pos; + if (erst_disable) return -ENODEV; + pos = (int *)&file->private_data; + + rc = erst_get_record_id_begin(pos); + if (rc) + return rc; + return nonseekable_open(inode, file); } +static int erst_dbg_release(struct inode *inode, struct file *file) +{ + erst_get_record_id_end(); + + return 0; +} + static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg) { int rc; @@ -79,23 +94,34 @@ static long erst_dbg_ioctl(struct file *f, unsigned int cmd, unsigned long arg) static ssize_t erst_dbg_read(struct file *filp, char __user *ubuf, size_t usize, loff_t *off) { - int rc; + int rc, *pos; ssize_t len = 0; u64 id; - if (*off != 0) + if (*off) return -EINVAL; if (mutex_lock_interruptible(&erst_dbg_mutex) != 0) return -EINTR; + pos = (int *)&filp->private_data; + retry_next: - rc = erst_get_next_record_id(&id); + rc = erst_get_record_id_next(pos, &id); if (rc) goto out; /* no more record */ - if (id == APEI_ERST_INVALID_RECORD_ID) + if (id == APEI_ERST_INVALID_RECORD_ID) { + /* + * If the persistent store is empty initially, the function + * 'erst_read' below will return "-ENOENT" value. This causes + * 'retry_next' label is entered again. The returned value + * should be zero indicating the read operation is EOF. + */ + len = 0; + goto out; + } retry: rc = len = erst_read(id, erst_dbg_buf, erst_dbg_buf_len); /* The record may be cleared by others, try read next record */ @@ -181,6 +207,7 @@ out: static const struct file_operations erst_dbg_ops = { .owner = THIS_MODULE, .open = erst_dbg_open, + .release = erst_dbg_release, .read = erst_dbg_read, .write = erst_dbg_write, .unlocked_ioctl = erst_dbg_ioctl, @@ -195,6 +222,10 @@ static struct miscdevice erst_dbg_dev = { static __init int erst_dbg_init(void) { + if (erst_disable) { + pr_info(ERST_DBG_PFX "ERST support is disabled.\n"); + return -ENODEV; + } return misc_register(&erst_dbg_dev); } |