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-rw-r--r--drivers/nvdimm/btt.h45
1 files changed, 44 insertions, 1 deletions
diff --git a/drivers/nvdimm/btt.h b/drivers/nvdimm/btt.h
index 884fbbbdd18a..db3cb6d4d0d4 100644
--- a/drivers/nvdimm/btt.h
+++ b/drivers/nvdimm/btt.h
@@ -27,6 +27,7 @@
#define MAP_ERR_MASK (1 << MAP_ERR_SHIFT)
#define MAP_LBA_MASK (~((1 << MAP_TRIM_SHIFT) | (1 << MAP_ERR_SHIFT)))
#define MAP_ENT_NORMAL 0xC0000000
+#define LOG_GRP_SIZE sizeof(struct log_group)
#define LOG_ENT_SIZE sizeof(struct log_entry)
#define ARENA_MIN_SIZE (1UL << 24) /* 16 MB */
#define ARENA_MAX_SIZE (1ULL << 39) /* 512 GB */
@@ -50,12 +51,52 @@ enum btt_init_state {
INIT_READY
};
+/*
+ * A log group represents one log 'lane', and consists of four log entries.
+ * Two of the four entries are valid entries, and the remaining two are
+ * padding. Due to an old bug in the padding location, we need to perform a
+ * test to determine the padding scheme being used, and use that scheme
+ * thereafter.
+ *
+ * In kernels prior to 4.15, 'log group' would have actual log entries at
+ * indices (0, 2) and padding at indices (1, 3), where as the correct/updated
+ * format has log entries at indices (0, 1) and padding at indices (2, 3).
+ *
+ * Old (pre 4.15) format:
+ * +-----------------+-----------------+
+ * | ent[0] | ent[1] |
+ * | 16B | 16B |
+ * | lba/old/new/seq | pad |
+ * +-----------------------------------+
+ * | ent[2] | ent[3] |
+ * | 16B | 16B |
+ * | lba/old/new/seq | pad |
+ * +-----------------+-----------------+
+ *
+ * New format:
+ * +-----------------+-----------------+
+ * | ent[0] | ent[1] |
+ * | 16B | 16B |
+ * | lba/old/new/seq | lba/old/new/seq |
+ * +-----------------------------------+
+ * | ent[2] | ent[3] |
+ * | 16B | 16B |
+ * | pad | pad |
+ * +-----------------+-----------------+
+ *
+ * We detect during start-up which format is in use, and set
+ * arena->log_index[(0, 1)] with the detected format.
+ */
+
struct log_entry {
__le32 lba;
__le32 old_map;
__le32 new_map;
__le32 seq;
- __le64 padding[2];
+};
+
+struct log_group {
+ struct log_entry ent[4];
};
struct btt_sb {
@@ -126,6 +167,7 @@ struct aligned_lock {
* @debugfs_dir: Debugfs dentry
* @flags: Arena flags - may signify error states.
* @err_lock: Mutex for synchronizing error clearing.
+ * @log_index: Indices of the valid log entries in a log_group
*
* arena_info is a per-arena handle. Once an arena is narrowed down for an
* IO, this struct is passed around for the duration of the IO.
@@ -158,6 +200,7 @@ struct arena_info {
/* Arena flags */
u32 flags;
struct mutex err_lock;
+ int log_index[2];
};
/**