mmc: core: general purpose MMC partition support.

It allows gerneral purpose partitions in MMC Device.  And I try to simply
make mmc_blk_alloc_parts using mmc_part structure suggested by Andrei
Warkentin.  After patching, we see general purpose partitions like this:
> cat /proc/partitions
          179 0 847872 mmcblk0
          179 192 4096 mmcblk0gp3
          179 160 4096 mmcblk0gp2
          179 128 4096 mmcblk0gp1
          179 96  1052672 mmcblk0gp0
          179 64  1024 mmcblk0boot1
          179 32  1024 mmcblk0boot0

Signed-off-by: Namjae Jeon <linkinjeon@gmail.com>
Acked-by: Andrei Warkentin <awarkentin@vmware.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

2 files changed, 65 insertions, 18 deletions

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index aa66d3f3abb1..2cf1ba6db910 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1473,26 +1473,29 @@ static int mmc_blk_alloc_part(struct mmc_card *card,
         return 0;
 }
 
+/* MMC Physical partitions consist of two boot partitions and
+ * up to four general purpose partitions.
+ * For each partition enabled in EXT_CSD a block device will be allocatedi
+ * to provide access to the partition.
+ */
+
 static int mmc_blk_alloc_parts(struct mmc_card *card, struct mmc_blk_data *md)
 {
-        int ret = 0;
+        int idx, ret = 0;
 
         if (!mmc_card_mmc(card))
                 return 0;
 
-        if (card->ext_csd.boot_size && mmc_boot_partition_access(card->host)) {
-                ret = mmc_blk_alloc_part(card, md, EXT_CSD_PART_CONFIG_ACC_BOOT0,
-                                         card->ext_csd.boot_size >> 9,
-                                         true,
-                                         "boot0");
-                if (ret)
-                        return ret;
-                ret = mmc_blk_alloc_part(card, md, EXT_CSD_PART_CONFIG_ACC_BOOT1,
-                                         card->ext_csd.boot_size >> 9,
-                                         true,
-                                         "boot1");
-                if (ret)
-                        return ret;
+        for (idx = 0; idx < card->nr_parts; idx++) {
+                if (card->part[idx].size) {
+                        ret = mmc_blk_alloc_part(card, md,
+                                card->part[idx].part_cfg,
+                                card->part[idx].size >> 9,
+                                card->part[idx].force_ro,
+                                card->part[idx].name);
+                        if (ret)
+                                return ret;
+                }
         }
 
         return ret;
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index c632b1faf70d..2a4c9a4d3c00 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -239,7 +239,9 @@ static int mmc_get_ext_csd(struct mmc_card *card, u8 **new_ext_csd)
  */
 static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
 {
-        int err = 0;
+        int err = 0, idx;
+        unsigned int part_size;
+        u8 hc_erase_grp_sz = 0, hc_wp_grp_sz = 0;
 
         BUG_ON(!card);
 
@@ -340,7 +342,14 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                  * There are two boot regions of equal size, defined in
                  * multiples of 128K.
                  */
-                card->ext_csd.boot_size = ext_csd[EXT_CSD_BOOT_MULT] << 17;
+                if (ext_csd[EXT_CSD_BOOT_MULT] && mmc_boot_partition_access(card->host)) {
+                        for (idx = 0; idx < MMC_NUM_BOOT_PARTITION; idx++) {
+                                part_size = ext_csd[EXT_CSD_BOOT_MULT] << 17;
+                                mmc_part_add(card, part_size,
+                                        EXT_CSD_PART_CONFIG_ACC_BOOT0 + idx,
+                                        "boot%d", idx, true);
+                        }
+                }
         }
 
         card->ext_csd.raw_hc_erase_gap_size =
@@ -362,9 +371,9 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                 card->ext_csd.raw_partition_support = ext_csd[EXT_CSD_PARTITION_SUPPORT];
                 if ((ext_csd[EXT_CSD_PARTITION_SUPPORT] & 0x2) &&
                     (ext_csd[EXT_CSD_PARTITION_ATTRIBUTE] & 0x1)) {
-                        u8 hc_erase_grp_sz =
+                        hc_erase_grp_sz =
                                 ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
-                        u8 hc_wp_grp_sz =
+                        hc_wp_grp_sz =
                                 ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
 
                         card->ext_csd.enhanced_area_en = 1;
@@ -393,6 +402,41 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
                         card->ext_csd.enhanced_area_offset = -EINVAL;
                         card->ext_csd.enhanced_area_size = -EINVAL;
                 }
+
+                /*
+                 * General purpose partition feature support --
+                 * If ext_csd has the size of general purpose partitions,
+                 * set size, part_cfg, partition name in mmc_part.
+                 */
+                if (ext_csd[EXT_CSD_PARTITION_SUPPORT] &
+                        EXT_CSD_PART_SUPPORT_PART_EN) {
+                        if (card->ext_csd.enhanced_area_en != 1) {
+                                hc_erase_grp_sz =
+                                        ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE];
+                                hc_wp_grp_sz =
+                                        ext_csd[EXT_CSD_HC_WP_GRP_SIZE];
+
+                                card->ext_csd.enhanced_area_en = 1;
+                        }
+
+                        for (idx = 0; idx < MMC_NUM_GP_PARTITION; idx++) {
+                                if (!ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3] &&
+                                !ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 1] &&
+                                !ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 2])
+                                        continue;
+                                part_size =
+                                (ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 2]
+                                        << 16) +
+                                (ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3 + 1]
+                                        << 8) +
+                                ext_csd[EXT_CSD_GP_SIZE_MULT + idx * 3];
+                                part_size *= (size_t)(hc_erase_grp_sz *
+                                        hc_wp_grp_sz);
+                                mmc_part_add(card, part_size << 19,
+                                        EXT_CSD_PART_CONFIG_ACC_GP0 + idx,
+                                        "gp%d", idx, false);
+                        }
+                }
                 card->ext_csd.sec_trim_mult =
                         ext_csd[EXT_CSD_SEC_TRIM_MULT];
                 card->ext_csd.sec_erase_mult =