[PATCH v8] mmc : general purpose partition support.

From: Namjae Jeon
Date: Mon Oct 03 2011 - 07:27:43 EST


It allows gerneral purpose partitions in MMC Device.
And I try to simpliy make mmc_blk_alloc_parts using mmc_part structure suggested by Andrei Warkentin.
After patching, we can 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@xxxxxxxxx>
---
drivers/mmc/card/block.c | 31 ++++++++++++++------------
drivers/mmc/core/mmc.c | 53 ++++++++++++++++++++++++++++++++++++++++++---
include/linux/mmc/card.h | 34 ++++++++++++++++++++++++++++-
include/linux/mmc/mmc.h | 5 +++-
4 files changed, 103 insertions(+), 20 deletions(-)

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 1ff5486..8452872 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -1377,26 +1377,29 @@ static int mmc_blk_alloc_part(struct mmc_card *card,
return 0;
}

+/* MMC Physical partition consist of two boot partitions and
+ * up to four general purpose partitions.
+ * For each partitions enabled in EXT_CSD
+ * The block device will allocated 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) {
- 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 5700b1c..f38bb6a 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 = -EINVAL, hc_wp_grp_sz = -EINVAL;

BUG_ON(!card);

@@ -340,7 +342,15 @@ 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]) {
+ 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 =
@@ -361,9 +371,9 @@ static int mmc_read_ext_csd(struct mmc_card *card, u8 *ext_csd)
*/
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;
@@ -392,6 +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 have 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 (hc_erase_grp_sz == -EINVAL ||
+ hc_wp_grp_sz == -EINVAL) {
+ 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_X_Y] &&
+ !ext_csd[EXT_CSD_GP_SIZE_MULT_X_Y + 1] &&
+ !ext_csd[EXT_CSD_GP_SIZE_MULT_X_Y + 2])
+ continue;
+ part_size =
+ (ext_csd[EXT_CSD_GP_SIZE_MULT_X_Y + 2] << 16) +
+ (ext_csd[EXT_CSD_GP_SIZE_MULT_X_Y + 1] << 8) +
+ ext_csd[EXT_CSD_GP_SIZE_MULT_X_Y];
+ 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 b460fc2..4bff3d0 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;
@@ -63,7 +64,6 @@ 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 */
@@ -157,6 +157,23 @@ struct sdio_func_tuple;

#define SDIO_MAX_FUNCS 7

+/* The number of MMC physical partitions
+ * It 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; /* it used to part_type */
+ char name[DISK_NAME_LEN];
+ bool force_ro; /* to make boot parts RO by default */
+};
+
/*
* MMC device
*/
@@ -216,9 +233,24 @@ 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 5a794cb..284a1b0 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_X_Y 143 /* R/W */
#define EXT_CSD_PARTITION_ATTRIBUTE 156 /* R/W */
#define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
#define EXT_CSD_WR_REL_PARAM 166 /* RO */
@@ -302,7 +303,9 @@ 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)
--
1.7.4.4

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