mmc: block: Support alternative_gpt_sector() operation

Support generic alternative_gpt_sector() block device operation.
It calculates location of GPT entry for eMMC of NVIDIA Tegra Android
devices. Add new MMC_CAP2_ALT_GPT_TEGRA flag that enables scanning of
alternative GPT sector and add raw_boot_mult field to mmc_ext_csd
which allows to get size of the boot partitions that is needed for
the calculation.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20210820004536.15791-4-digetx@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/drivers/mmc/core/block.c b/drivers/mmc/core/block.c
index 4c11f17..6a15fdf 100644 (file)
--- a/drivers/mmc/core/block.c
+++ b/drivers/mmc/core/block.c
@@ -831,6 +831,26 @@ static int mmc_blk_compat_ioctl(struct block_device *bdev, fmode_t mode,
 }
 #endif
 
 }
 #endif
 

+static int mmc_blk_alternative_gpt_sector(struct gendisk *disk,
+                                         sector_t *sector)
+{
+       struct mmc_blk_data *md;
+       int ret;
+
+       md = mmc_blk_get(disk);
+       if (!md)
+               return -EINVAL;
+
+       if (md->queue.card)
+               ret = mmc_card_alternative_gpt_sector(md->queue.card, sector);
+       else
+               ret = -ENODEV;
+
+       mmc_blk_put(md);
+
+       return ret;
+}
+

 static const struct block_device_operations mmc_bdops = {
        .open                   = mmc_blk_open,
        .release                = mmc_blk_release,
 static const struct block_device_operations mmc_bdops = {
        .open                   = mmc_blk_open,
        .release                = mmc_blk_release,


@@ -840,6 +860,7 @@ static const struct block_device_operations mmc_bdops = {
 #ifdef CONFIG_COMPAT
        .compat_ioctl           = mmc_blk_compat_ioctl,
 #endif
 #ifdef CONFIG_COMPAT
        .compat_ioctl           = mmc_blk_compat_ioctl,
 #endif

+       .alternative_gpt_sector = mmc_blk_alternative_gpt_sector,

 };
 
 static int mmc_blk_part_switch_pre(struct mmc_card *card,
 };
 
 static int mmc_blk_part_switch_pre(struct mmc_card *card,

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 95fedcf..605f5e8 100644 (file)
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2149,6 +2149,41 @@ int mmc_detect_card_removed(struct mmc_host *host)
 }
 EXPORT_SYMBOL(mmc_detect_card_removed);
 
 }
 EXPORT_SYMBOL(mmc_detect_card_removed);
 

+int mmc_card_alternative_gpt_sector(struct mmc_card *card, sector_t *gpt_sector)
+{
+       unsigned int boot_sectors_num;
+
+       if ((!(card->host->caps2 & MMC_CAP2_ALT_GPT_TEGRA)))
+               return -EOPNOTSUPP;
+
+       /* filter out unrelated cards */
+       if (card->ext_csd.rev < 3 ||
+           !mmc_card_mmc(card) ||
+           !mmc_card_is_blockaddr(card) ||
+            mmc_card_is_removable(card->host))
+               return -ENOENT;
+
+       /*
+        * eMMC storage has two special boot partitions in addition to the
+        * main one.  NVIDIA's bootloader linearizes eMMC boot0->boot1->main
+        * accesses, this means that the partition table addresses are shifted
+        * by the size of boot partitions.  In accordance with the eMMC
+        * specification, the boot partition size is calculated as follows:
+        *
+        *      boot partition size = 128K byte x BOOT_SIZE_MULT
+        *
+        * Calculate number of sectors occupied by the both boot partitions.
+        */
+       boot_sectors_num = card->ext_csd.raw_boot_mult * SZ_128K /
+                          SZ_512 * MMC_NUM_BOOT_PARTITION;
+
+       /* Defined by NVIDIA and used by Android devices. */
+       *gpt_sector = card->ext_csd.sectors - boot_sectors_num - 1;
+
+       return 0;
+}
+EXPORT_SYMBOL(mmc_card_alternative_gpt_sector);
+

 void mmc_rescan(struct work_struct *work)
 {
        struct mmc_host *host =
 void mmc_rescan(struct work_struct *work)
 {
        struct mmc_host *host =

diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index 0c4de20..7931a4f 100644 (file)
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -119,6 +119,8 @@ void mmc_release_host(struct mmc_host *host);
 void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx);
 void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx);
 
 void mmc_get_card(struct mmc_card *card, struct mmc_ctx *ctx);
 void mmc_put_card(struct mmc_card *card, struct mmc_ctx *ctx);
 

+int mmc_card_alternative_gpt_sector(struct mmc_card *card, sector_t *sector);
+

 /**
  *     mmc_claim_host - exclusively claim a host
  *     @host: mmc host to claim
 /**
  *     mmc_claim_host - exclusively claim a host
  *     @host: mmc host to claim

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 838726b..29e58ff 100644 (file)
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -418,6 +418,8 @@ static int mmc_decode_ext_csd(struct mmc_card *card, u8 *ext_csd)
                ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT];
        card->ext_csd.raw_hc_erase_grp_size =
                ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
                ext_csd[EXT_CSD_ERASE_TIMEOUT_MULT];
        card->ext_csd.raw_hc_erase_grp_size =
                ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];

+       card->ext_csd.raw_boot_mult =
+               ext_csd[EXT_CSD_BOOT_MULT];

        if (card->ext_csd.rev >= 3) {
                u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];
                card->ext_csd.part_config = ext_csd[EXT_CSD_PART_CONFIG];
        if (card->ext_csd.rev >= 3) {
                u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];
                card->ext_csd.part_config = ext_csd[EXT_CSD_PART_CONFIG];

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 74e6c06..37f9758 100644 (file)
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -109,6 +109,7 @@ struct mmc_ext_csd {
        u8                      raw_hc_erase_gap_size;  /* 221 */
        u8                      raw_erase_timeout_mult; /* 223 */
        u8                      raw_hc_erase_grp_size;  /* 224 */
        u8                      raw_hc_erase_gap_size;  /* 221 */
        u8                      raw_erase_timeout_mult; /* 223 */
        u8                      raw_hc_erase_grp_size;  /* 224 */

+       u8                      raw_boot_mult;          /* 226 */

        u8                      raw_sec_trim_mult;      /* 229 */
        u8                      raw_sec_erase_mult;     /* 230 */
        u8                      raw_sec_feature_support;/* 231 */
        u8                      raw_sec_trim_mult;      /* 229 */
        u8                      raw_sec_erase_mult;     /* 230 */
        u8                      raw_sec_feature_support;/* 231 */

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 0abd47e..78dadf8 100644 (file)
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -398,6 +398,7 @@ struct mmc_host {
 #else
 #define MMC_CAP2_CRYPTO                0
 #endif
 #else
 #define MMC_CAP2_CRYPTO                0
 #endif

+#define MMC_CAP2_ALT_GPT_TEGRA (1 << 28)       /* Host with eMMC that has GPT entry at a non-standard location */

 
        int                     fixed_drv_type; /* fixed driver type for non-removable media */
 
 
        int                     fixed_drv_type; /* fixed driver type for non-removable media */