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, 37 insertions, 2 deletions

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 5294ddf382ae..92762865f7e0 100644
--- 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
  */
@@ -219,9 +236,24 @@ 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 50af22730c74..ea558eb44c79 100644
--- 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)