Merge tag 'i2c-host-6.13-p1' of git://git.kernel.org/pub/scm/linux/kernel/git/andi.shyti/linux into i2c/for-mergewindow

i2c-host updates for v6.13, part 1

Major Improvements and Refactoring:

 - All controllers using the 'remove_new' callback have been
   reverted to use the 'remove' callback.

 - Intel SCH controller underwent significant refactoring,
   this brings love and a modern look to the driver.

 - PIIX4 driver refactored to enable usage by other drivers
   (e.g., AMD ASF).

 - iMX/MXC improved message handling to reduce protocol overhead:
     Refactored DMA/non-DMA read/write and bus polling mechanisms
     to achieve this.

 - ACPI documentation for PIIX4.

New Features:

 - i2c-cadence added support for atomic transfers.
 - Qualcomm CII added support for a 32MHz serial engine clock.

Deprecated Features:

 - Dropped outdated support for AMD756 S4882 and NFORCE2 S4985. If
   somebody misses this, Jean will rewrite support using the proper
   i2c mux framework.

New Hardware Support:

 - Added support for:
   - Intel Panther Lake (new ID)
   - AMD ASF (new driver)
   - S32G2/S32G3 SoCs (new ID)
   - Realtek RTL I2C Controller (new driver)
   - HJMC01 DesignWare ACPI HID (new ID)
   - PIC64GX to Microchip Core (new ID)
   - Qualcomm SDM670 to Qualcomm CCI (new ID)

1 files changed, 22 insertions, 16 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 25d191f1ac10f..1d93e1202c339 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -230,7 +230,12 @@ static bool mergeable_maps(const struct extent_map *prev, const struct extent_ma
 	if (extent_map_end(prev) != next->start)
 		return false;
 
-	if (prev->flags != next->flags)
+	/*
+	 * The merged flag is not an on-disk flag, it just indicates we had the
+	 * extent maps of 2 (or more) adjacent extents merged, so factor it out.
+	 */
+	if ((prev->flags & ~EXTENT_FLAG_MERGED) !=
+	    (next->flags & ~EXTENT_FLAG_MERGED))
 		return false;
 
 	if (next->disk_bytenr < EXTENT_MAP_LAST_BYTE - 1)
@@ -243,13 +248,19 @@ static bool mergeable_maps(const struct extent_map *prev, const struct extent_ma
 /*
  * Handle the on-disk data extents merge for @prev and @next.
  *
+ * @prev:    left extent to merge
+ * @next:    right extent to merge
+ * @merged:  the extent we will not discard after the merge; updated with new values
+ *
+ * After this, one of the two extents is the new merged extent and the other is
+ * removed from the tree and likely freed. Note that @merged is one of @prev/@next
+ * so there is const/non-const aliasing occurring here.
+ *
  * Only touches disk_bytenr/disk_num_bytes/offset/ram_bytes.
  * For now only uncompressed regular extent can be merged.
- *
- * @prev and @next will be both updated to point to the new merged range.
- * Thus one of them should be removed by the caller.
  */
-static void merge_ondisk_extents(struct extent_map *prev, struct extent_map *next)
+static void merge_ondisk_extents(const struct extent_map *prev, const struct extent_map *next,
+				 struct extent_map *merged)
 {
 	u64 new_disk_bytenr;
 	u64 new_disk_num_bytes;
@@ -284,15 +295,10 @@ static void merge_ondisk_extents(struct extent_map *prev, struct extent_map *nex
 			     new_disk_bytenr;
 	new_offset = prev->disk_bytenr + prev->offset - new_disk_bytenr;
 
-	prev->disk_bytenr = new_disk_bytenr;
-	prev->disk_num_bytes = new_disk_num_bytes;
-	prev->ram_bytes = new_disk_num_bytes;
-	prev->offset = new_offset;
-
-	next->disk_bytenr = new_disk_bytenr;
-	next->disk_num_bytes = new_disk_num_bytes;
-	next->ram_bytes = new_disk_num_bytes;
-	next->offset = new_offset;
+	merged->disk_bytenr = new_disk_bytenr;
+	merged->disk_num_bytes = new_disk_num_bytes;
+	merged->ram_bytes = new_disk_num_bytes;
+	merged->offset = new_offset;
 }
 
 static void dump_extent_map(struct btrfs_fs_info *fs_info, const char *prefix,
@@ -361,7 +367,7 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
 			em->generation = max(em->generation, merge->generation);
 
 			if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)
-				merge_ondisk_extents(merge, em);
+				merge_ondisk_extents(merge, em, em);
 			em->flags |= EXTENT_FLAG_MERGED;
 
 			validate_extent_map(fs_info, em);
@@ -378,7 +384,7 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
 	if (rb && can_merge_extent_map(merge) && mergeable_maps(em, merge)) {
 		em->len += merge->len;
 		if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)
-			merge_ondisk_extents(em, merge);
+			merge_ondisk_extents(em, merge, em);
 		validate_extent_map(fs_info, em);
 		rb_erase(&merge->rb_node, &tree->root);
 		RB_CLEAR_NODE(&merge->rb_node);