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>

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index aa66d3f..2cf1ba6 100644 (file)
--- 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 c632b1f..2a4c9a4 100644 (file)
--- 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 =

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 5294ddf..9276286 100644 (file)
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -12,6 +12,7 @@
 
 #include <linux/mmc/core.h>
 #include <linux/mod_devicetable.h>
+#include <linux/genhd.h>
 
 struct mmc_cid {
        unsigned int            manfid;
@@ -64,7 +65,6 @@ struct mmc_ext_csd {
        bool                    enhanced_area_en;       /* enable bit */
        unsigned long long      enhanced_area_offset;   /* Units: Byte */
        unsigned int            enhanced_area_size;     /* Units: KB */
-       unsigned int            boot_size;              /* in bytes */
        u8                      raw_partition_support;  /* 160 */
        u8                      raw_erased_mem_count;   /* 181 */
        u8                      raw_ext_csd_structure;  /* 194 */
@@ -158,6 +158,23 @@ struct sdio_func_tuple;
 
 #define SDIO_MAX_FUNCS         7
 
+/* The number of MMC physical partitions.  These consist of:
+ * boot partitions (2), general purpose partitions (4) in MMC v4.4.
+ */
+#define MMC_NUM_BOOT_PARTITION 2
+#define MMC_NUM_GP_PARTITION   4
+#define MMC_NUM_PHY_PARTITION  6
+
+/*
+ * MMC Physical partitions
+ */
+struct mmc_part {
+       unsigned int    size;   /* partition size (in bytes) */
+       unsigned int    part_cfg;       /* partition type */
+       char    name[DISK_NAME_LEN];
+       bool    force_ro;       /* to make boot parts RO by default */
+};
+
 /*
  * MMC device
  */
@@ -219,8 +236,23 @@ struct mmc_card {
        unsigned int            sd_bus_speed;   /* Bus Speed Mode set for the card */
 
        struct dentry           *debugfs_root;
+       struct mmc_part part[MMC_NUM_PHY_PARTITION]; /* physical partitions */
+       unsigned int    nr_parts;
 };
 
+/*
+ * This function fill contents in mmc_part.
+ */
+static inline void mmc_part_add(struct mmc_card *card, unsigned int size,
+                       unsigned int part_cfg, char *name, int idx, bool ro)
+{
+       card->part[card->nr_parts].size = size;
+       card->part[card->nr_parts].part_cfg = part_cfg;
+       sprintf(card->part[card->nr_parts].name, name, idx);
+       card->part[card->nr_parts].force_ro = ro;
+       card->nr_parts++;
+}
+
 /*
  *  The world is not perfect and supplies us with broken mmc/sdio devices.
  *  For at least some of these bugs we need a work-around.

diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 50af227..ea558eb 100644 (file)
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -270,6 +270,7 @@ struct _mmc_csd {
  * EXT_CSD fields
  */
 
+#define EXT_CSD_GP_SIZE_MULT           143     /* R/W */
 #define EXT_CSD_PARTITION_ATTRIBUTE    156     /* R/W */
 #define EXT_CSD_PARTITION_SUPPORT      160     /* RO */
 #define EXT_CSD_RST_N_FUNCTION         162     /* R/W */
@@ -313,7 +314,9 @@ struct _mmc_csd {
 
 #define EXT_CSD_PART_CONFIG_ACC_MASK   (0x7)
 #define EXT_CSD_PART_CONFIG_ACC_BOOT0  (0x1)
-#define EXT_CSD_PART_CONFIG_ACC_BOOT1  (0x2)
+#define EXT_CSD_PART_CONFIG_ACC_GP0    (0x4)
+
+#define EXT_CSD_PART_SUPPORT_PART_EN   (0x1)
 
 #define EXT_CSD_CMD_SET_NORMAL         (1<<0)
 #define EXT_CSD_CMD_SET_SECURE         (1<<1)