mmc: core: Calculate the discard arg only once

In MMC, the discard arg is a read-only ext_csd parameter - set it once
on card init. To be consistent, do that for SD as well even though its
discard arg is always 0x0.

Signed-off-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

6 files changed, 21 insertions, 11 deletions

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index dc55bdfede92..54a7b7410441 100644
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -1124,7 +1124,7 @@ static void mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
 {
         struct mmc_blk_data *md = mq->blkdata;
         struct mmc_card *card = md->queue.card;
-        unsigned int from, nr, arg;
+        unsigned int from, nr;
         int err = 0, type = MMC_BLK_DISCARD;
         blk_status_t status = BLK_STS_OK;
 
@@ -1136,24 +1136,18 @@ static void mmc_blk_issue_discard_rq(struct mmc_queue *mq, struct request *req)
         from = blk_rq_pos(req);
         nr = blk_rq_sectors(req);
 
-        if (mmc_can_discard(card))
-                arg = MMC_DISCARD_ARG;
-        else if (mmc_can_trim(card))
-                arg = MMC_TRIM_ARG;
-        else
-                arg = MMC_ERASE_ARG;
         do {
                 err = 0;
                 if (card->quirks & MMC_QUIRK_INAND_CMD38) {
                         err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
                                          INAND_CMD38_ARG_EXT_CSD,
-                                         arg == MMC_TRIM_ARG ?
+                                         card->erase_arg == MMC_TRIM_ARG ?
                                          INAND_CMD38_ARG_TRIM :
                                          INAND_CMD38_ARG_ERASE,
                                          0);
                 }
                 if (!err)
-                        err = mmc_erase(card, from, nr, arg);
+                        err = mmc_erase(card, from, nr, card->erase_arg);
         } while (err == -EIO && !mmc_blk_reset(md, card->host, type));
         if (err)
                 status = BLK_STS_IOERR;
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 5bd58b95d318..de0f1a1f0a63 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2164,7 +2164,7 @@ static unsigned int mmc_align_erase_size(struct mmc_card *card,
  * @card: card to erase
  * @from: first sector to erase
  * @nr: number of sectors to erase
- * @arg: erase command argument (SD supports only %MMC_ERASE_ARG)
+ * @arg: erase command argument (SD supports only %SD_ERASE_ARG)
  *
  * Caller must claim host before calling this function.
  */
@@ -2181,7 +2181,7 @@ int mmc_erase(struct mmc_card *card, unsigned int from, unsigned int nr,
         if (!card->erase_size)
                 return -EOPNOTSUPP;
 
-        if (mmc_card_sd(card) && arg != MMC_ERASE_ARG)
+        if (mmc_card_sd(card) && arg != SD_ERASE_ARG)
                 return -EOPNOTSUPP;
 
         if ((arg & MMC_SECURE_ARGS) &&
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index da892a599524..09c688f5ff65 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -1743,6 +1743,14 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
                         card->ext_csd.power_off_notification = EXT_CSD_POWER_ON;
         }
 
+        /* set erase_arg */
+        if (mmc_can_discard(card))
+                card->erase_arg = MMC_DISCARD_ARG;
+        else if (mmc_can_trim(card))
+                card->erase_arg = MMC_TRIM_ARG;
+        else
+                card->erase_arg = MMC_ERASE_ARG;
+
         /*
          * Select timing interface
          */
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index d0d9f90e7cdf..bd48b28d641b 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -271,6 +271,8 @@ static int mmc_read_ssr(struct mmc_card *card)
                 }
         }
 
+        card->erase_arg = SD_ERASE_ARG;
+
         return 0;
 }
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 8ef330027b13..e2bbceb80725 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -277,6 +277,7 @@ struct mmc_card {
         unsigned int            erase_shift;    /* if erase unit is power 2 */
         unsigned int            pref_erase;     /* in sectors */
         unsigned int            eg_boundary;    /* don't cross erase-group boundaries */
+        unsigned int            erase_arg;      /* erase / trim / discard */
         u8                      erased_byte;    /* value of erased bytes */
 
         u32                     raw_cid[4];     /* raw card CID */
diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h
index 1ebcf9ba1256..1a6d10fdf682 100644
--- a/include/linux/mmc/sd.h
+++ b/include/linux/mmc/sd.h
@@ -91,4 +91,9 @@
 #define SD_SWITCH_ACCESS_DEF    0
 #define SD_SWITCH_ACCESS_HS     1
 
+/*
+ * Erase/discard
+ */
+#define SD_ERASE_ARG                    0x00000000
+
 #endif /* LINUX_MMC_SD_H */