[PATCHv4] mmc: rpmb: fixes pause retune on all RPMB partitions.

[Jorge Ramirez-Ortiz <jorge@foundries.io>]

When RPMB was converted to a character device, it added support for
multiple RPMB partitions (Commit 97548575bef3 ("mmc: block: Convert RPMB
to a character device").

One of the changes in this commit was transforming the variable
target_part defined in __mmc_blk_ioctl_cmd into a bitmask.

This inadvertedly regressed the validation check done in
mmc_blk_part_switch_pre() and mmc_blk_part_switch_post().

This commit fixes that regression.

Fixes: 97548575bef3 ("mmc: block: Convert RPMB to a character device")
Signed-off-by: Jorge Ramirez-Ortiz <jorge@foundries.io>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: <stable@vger.kernel.org> # v4.14+
---

  v2:
     fixes parenthesis around condition
  v3:
     adds stable to commit header
  v4:
     fixes the stable version to v4.14
     adds Reviewed-by

 drivers/mmc/core/block.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 152dfe593c43..13093d26bf81 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -851,9 +851,10 @@ static const struct block_device_operations mmc_bdops = {
 static int mmc_blk_part_switch_pre(struct mmc_card *card,
 				   unsigned int part_type)
 {
+	const unsigned int mask = EXT_CSD_PART_CONFIG_ACC_RPMB;
 	int ret = 0;

-	if (part_type == EXT_CSD_PART_CONFIG_ACC_RPMB) {
+	if ((part_type & mask) == mask) {
 		if (card->ext_csd.cmdq_en) {
 			ret = mmc_cmdq_disable(card);
 			if (ret)
@@ -868,9 +869,10 @@ static int mmc_blk_part_switch_pre(struct mmc_card *card,
 static int mmc_blk_part_switch_post(struct mmc_card *card,
 				    unsigned int part_type)
 {
+	const unsigned int mask = EXT_CSD_PART_CONFIG_ACC_RPMB;
 	int ret = 0;

-	if (part_type == EXT_CSD_PART_CONFIG_ACC_RPMB) {
+	if ((part_type & mask) == mask) {
 		mmc_retune_unpause(card->host);
 		if (card->reenable_cmdq && !card->ext_csd.cmdq_en)
 			ret = mmc_cmdq_enable(card);
@@ -3143,4 +3145,3 @@ module_exit(mmc_blk_exit);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("Multimedia Card (MMC) block device driver");
-
--
2.34.1