[resent RFC 19/22] dm: blk: call efi's device-removal hook

[AKASHI Takahiro]

Adding the callback function, efi_disk_delete(), in block devices's
pre_remove hook will allows for automatically deleting efi_disk objects
per block device.

This will eliminate any improper efi_disk objects which hold a link to
non-existing udevice structures when associated block devices are physically
un-plugged or udevices are once removed (and re-created) by executing commands
like "scsi rescan."

Signed-off-by: AKASHI Takahiro <takahiro.aka...@linaro.org>
---
 drivers/block/blk-uclass.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/drivers/block/blk-uclass.c b/drivers/block/blk-uclass.c
index ce45cf0a8768..b8ad267c6c61 100644
--- a/drivers/block/blk-uclass.c
+++ b/drivers/block/blk-uclass.c
@@ -847,6 +847,16 @@ static int blk_post_probe(struct udevice *dev)
        return 0;
 }
 
+static int blk_pre_remove(struct udevice *dev)
+{
+       if (CONFIG_IS_ENABLED(EFI_LOADER)) {
+               if (efi_disk_delete(dev))
+                       debug("*** efi_pre_remove_device failed\n");
+       }
+
+       return 0;
+}
+
 static int blk_part_post_probe(struct udevice *dev)
 {
        if (CONFIG_IS_ENABLED(EFI_LOADER)) {
@@ -861,10 +871,21 @@ static int blk_part_post_probe(struct udevice *dev)
        return 0;
 }
 
+static int blk_part_pre_remove(struct udevice *dev)
+{
+       if (CONFIG_IS_ENABLED(EFI_LOADER)) {
+               if (efi_disk_delete(dev))
+                       debug("*** efi_pre_remove_device failed\n");
+       }
+
+       return 0;
+}
+
 UCLASS_DRIVER(blk) = {
        .id             = UCLASS_BLK,
        .name           = "blk",
        .post_probe     = blk_post_probe,
+       .pre_remove     = blk_pre_remove,
        .per_device_plat_auto   = sizeof(struct blk_desc),
 };
 
@@ -937,6 +958,7 @@ U_BOOT_DRIVER(blk_partition) = {
 UCLASS_DRIVER(partition) = {
        .id             = UCLASS_PARTITION,
        .post_probe     = blk_part_post_probe,
+       .pre_remove     = blk_part_pre_remove,
        .per_device_plat_auto   = sizeof(struct disk_part),
        .name           = "partition",
 };
-- 
2.33.0