[PATCH v2 2/6] drivers: block: Introduce blk_flush()/blk_dflush()

[dmukhin at ford.com]

From: Denis Mukhin <dmukhin at ford.com> 

Add generic flush operations for committing dirty data to the storage
device.

This provides a common block-layer interface for flushing pending
writes, allowing callers to ensure that data buffered by the block
device or its backing implementation is written out to the underlying
storage.

Signed-off-by: Denis Mukhin <dmukhin at ford.com>
---
Changes since v1:
- new patch
---
 disk/disk-uclass.c         |  6 ++++++
 drivers/block/blk-uclass.c | 18 ++++++++++++++++++
 include/blk.h              | 28 ++++++++++++++++++++++++++++
 include/part.h             |  8 ++++++++
 4 files changed, 60 insertions(+)

diff --git a/disk/disk-uclass.c b/disk/disk-uclass.c
index ee3cc4407d76..1a87f7dffa7c 100644
--- a/disk/disk-uclass.c
+++ b/disk/disk-uclass.c
@@ -122,6 +122,11 @@ unsigned long disk_blk_erase(struct udevice *dev, lbaint_t start,
 			 blkcnt);
 }
 
+unsigned long disk_blk_flush(struct udevice *dev)
+{
+	return blk_flush(dev_get_parent(dev));
+}
+
 UCLASS_DRIVER(partition) = {
 	.id		= UCLASS_PARTITION,
 	.per_device_plat_auto	= sizeof(struct disk_part),
@@ -132,6 +137,7 @@ static const struct blk_ops blk_part_ops = {
 	.read	= disk_blk_read,
 	.write	= disk_blk_write,
 	.erase	= disk_blk_erase,
+	.flush	= disk_blk_flush,
 };
 
 U_BOOT_DRIVER(blk_partition) = {
diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index 73c24fd91763..0be1fdab1ba5 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -514,6 +514,19 @@ long blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt)
 	return ops->erase(dev, start, blkcnt);
 }
 
+long blk_flush(struct udevice *dev)
+{
+	struct blk_desc *desc = dev_get_uclass_plat(dev);
+	const struct blk_ops *ops = blk_get_ops(dev);
+
+	if (!ops->flush)
+		return -ENOSYS;
+
+	blkcache_invalidate(desc->uclass_id, desc->devnum);
+
+	return ops->flush(dev);
+}
+
 ulong blk_dread(struct blk_desc *desc, lbaint_t start, lbaint_t blkcnt,
 		void *buffer)
 {
@@ -531,6 +544,11 @@ ulong blk_derase(struct blk_desc *desc, lbaint_t start, lbaint_t blkcnt)
 	return blk_erase(desc->bdev, start, blkcnt);
 }
 
+ulong blk_dflush(struct blk_desc *desc)
+{
+	return blk_flush(desc->bdev);
+}
+
 int blk_find_from_parent(struct udevice *parent, struct udevice **devp)
 {
 	struct udevice *dev;
diff --git a/include/blk.h b/include/blk.h
index 8d1b70cabd31..98e1db7a58f1 100644
--- a/include/blk.h
+++ b/include/blk.h
@@ -99,6 +99,7 @@ struct blk_desc {
 	unsigned long	(*block_erase)(struct blk_desc *block_dev,
 				       lbaint_t start,
 				       lbaint_t blkcnt);
+	unsigned long	(*block_flush)(struct blk_desc *block_dev);
 	void		*priv;		/* driver private struct pointer */
 #endif
 };
@@ -275,6 +276,14 @@ struct blk_ops {
 	 */
 	int (*buffer_aligned)(struct udevice *dev, struct bounce_buffer *state);
 #endif	/* CONFIG_BOUNCE_BUFFER */
+
+	/**
+	 * flush() -  commit all dirty data to storage
+	 *
+	 * @dev:	Device to flush
+	 * @return 0 if OK, -ve on error
+	 */
+	unsigned long (*flush)(struct udevice *dev);
 };
 
 #if CONFIG_IS_ENABLED(BLK)
@@ -291,6 +300,7 @@ unsigned long blk_dwrite(struct blk_desc *block_dev, lbaint_t start,
 			 lbaint_t blkcnt, const void *buffer);
 unsigned long blk_derase(struct blk_desc *block_dev, lbaint_t start,
 			 lbaint_t blkcnt);
+unsigned long blk_dflush(struct blk_desc *block_dev);
 
 #endif /* BLK */
 
@@ -331,6 +341,14 @@ long blk_write(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
  */
 long blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt);
 
+/**
+ * blk_flush() - Commit data to a block device
+ *
+ * @dev: Device to flush
+ * @return 0 if operation succeeded, or -ve on error.
+ */
+long blk_flush(struct udevice *dev);
+
 /**
  * blk_find_device() - Find a block device
  *
@@ -559,6 +577,16 @@ static inline ulong blk_derase(struct blk_desc *block_dev, lbaint_t start,
 	return block_dev->block_erase(block_dev, start, blkcnt);
 }
 
+static inline ulong blk_dflush(struct blk_desc *block_dev)
+{
+	if (!block_dev->block_flush)
+		return -ENOSYS;
+
+	blkcache_invalidate(block_dev->uclass_id, block_dev->devnum);
+
+	return block_dev->block_flush(block_dev);
+}
+
 /**
  * struct blk_driver - Driver for block interface types
  *
diff --git a/include/part.h b/include/part.h
index 15daacd7faaa..63982d7b9370 100644
--- a/include/part.h
+++ b/include/part.h
@@ -454,6 +454,14 @@ ulong disk_blk_write(struct udevice *dev, lbaint_t start, lbaint_t blkcnt,
  */
 ulong disk_blk_erase(struct udevice *dev, lbaint_t start, lbaint_t blkcnt);
 
+/**
+ * disk_blk_flush() - commit data to a disk
+ *
+ * @dev:	Device to flush
+ * Return:	0 success, or -ve error number (see the IS_ERR_VALUE() macro
+ */
+ulong disk_blk_flush(struct udevice *dev);
+
 /*
  * We don't support printing partition information in SPL and only support
  * getting partition information in a few cases.
-- 
2.54.0