mmc: card: Don't access RPMB partitions for normal read/write

During kernel boot, it will try to read some logical sectors
of each block device node for the possible partition table.

But since RPMB partition is special and can not be accessed
by normal eMMC read / write CMDs, it will cause below error
messages during kernel boot:
...
 mmc0: Got data interrupt 0x00000002 even though no data operation was in progress.
 mmcblk0rpmb: error -110 transferring data, sector 0, nr 32, cmd response 0x900, card status 0xb00
 mmcblk0rpmb: retrying using single block read
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 mmcblk0rpmb: timed out sending r/w cmd command, card status 0x400900
 end_request: I/O error, dev mmcblk0rpmb, sector 0
 Buffer I/O error on device mmcblk0rpmb, logical block 0
 end_request: I/O error, dev mmcblk0rpmb, sector 8
 Buffer I/O error on device mmcblk0rpmb, logical block 1
 end_request: I/O error, dev mmcblk0rpmb, sector 16
 Buffer I/O error on device mmcblk0rpmb, logical block 2
 end_request: I/O error, dev mmcblk0rpmb, sector 24
 Buffer I/O error on device mmcblk0rpmb, logical block 3
...

This patch will discard the access request in eMMC queue if
it is RPMB partition access request. By this way, it avoids
trigger above error messages.

Fixes: 090d25fe ("mmc: core: Expose access to RPMB partition")
Signed-off-by: Yunpeng Gao <yunpeng.gao@intel.com>
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Tested-by: Michael Shigorin <mike@altlinux.org>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/card/block.c

@@ -1029,6 +1029,18 @@ static inline void mmc_blk_reset_success(struct mmc_blk_data *md, int type)
 	md->reset_done &= ~type;
 }
 
+int mmc_access_rpmb(struct mmc_queue *mq)
+{
+	struct mmc_blk_data *md = mq->data;
+	/*
+	 * If this is a RPMB partition access, return ture
+	 */
+	if (md && md->part_type == EXT_CSD_PART_CONFIG_ACC_RPMB)
+		return true;
+
+	return false;
+}
+
 static int mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
 {
 	struct mmc_blk_data *md = mq->data;

drivers/mmc/card/queue.c

@@ -38,7 +38,7 @@ static int mmc_prep_request(struct request_queue *q, struct request *req)
 		return BLKPREP_KILL;
 	}
 
-	if (mq && mmc_card_removed(mq->card))
+	if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
 		return BLKPREP_KILL;
 
 	req->cmd_flags |= REQ_DONTPREP;

drivers/mmc/card/queue.h

@@ -73,4 +73,6 @@ extern void mmc_queue_bounce_post(struct mmc_queue_req *);
 extern int mmc_packed_init(struct mmc_queue *, struct mmc_card *);
 extern void mmc_packed_clean(struct mmc_queue *);
 
+extern int mmc_access_rpmb(struct mmc_queue *);
+
 #endif