@@ -2,3 +2,5 @@
- this file
mmc-dev-attrs.txt
- info on SD and MMC device attributes
+mmc-dev-parts.txt
+ - info on SD and MMC device partitions
@@ -1,3 +1,13 @@
+SD and MMC Block Device Attributes
+==================================
+
+These attributes are defined for the block devices associated with the
+SD or MMC device.
+
+The following attributes are read/write.
+
+ force_ro Enforce read-only access even if write protect switch is off.
+
SD and MMC Device Attributes
============================
new file mode 100644
@@ -0,0 +1,26 @@
+SD and MMC Device Partitions
+============================
+
+Device partitions are additional logical block devices present
+on the SD/MMC device.
+
+As of this writing, MMC boot partitions as supported and exposed as
+/dev/mmcblkXboot0 and /dev/mmcblkXboot1, where X is the index of the
+parent /dev/mmcblkX.
+
+MMC Boot Partitions
+===================
+
+Read and write access is provided to the two MMC boot partitions. Due
+to the sensitive nature of the boot partition contents, which often store
+a bootloader or bootloader configuration tables crucial to booting the platform,
+write access is by default disabled to reduce the chance of accidental bricking.
+
+To enable write access to /dev/mmcblkXbootY, disable the forced read-only
+access:
+
+echo 0 > /sys/block/mmcblkXbootY/force_ro
+
+To re-enable read-only access:
+
+echo 1 > /sys/block/mmcblkXbootY/force_ro
@@ -76,9 +76,19 @@ struct mmc_blk_data {
spinlock_t lock;
struct gendisk *disk;
struct mmc_queue queue;
+ struct list_head part;
unsigned int usage;
unsigned int read_only;
+ unsigned int part_type;
+
+ /*
+ * Only set in main mmc_blk_data associated
+ * with mmc_card with mmc_set_drvdata, and keeps
+ * track of the current selected device partition.
+ */
+ unsigned int part_curr;
+ struct device_attribute force_ro;
};
static DEFINE_MUTEX(open_lock);
@@ -101,17 +111,22 @@ static struct mmc_blk_data *mmc_blk_get(struct gendisk *disk)
return md;
}
+static inline int mmc_get_devidx(struct gendisk *disk)
+{
+ int devmaj = MAJOR(disk_devt(disk));
+ int devidx = MINOR(disk_devt(disk)) / perdev_minors;
+
+ if (!devmaj)
+ devidx = disk->first_minor / perdev_minors;
+ return devidx;
+}
+
static void mmc_blk_put(struct mmc_blk_data *md)
{
mutex_lock(&open_lock);
md->usage--;
if (md->usage == 0) {
- int devmaj = MAJOR(disk_devt(md->disk));
- int devidx = MINOR(disk_devt(md->disk)) / perdev_minors;
-
- if (!devmaj)
- devidx = md->disk->first_minor / perdev_minors;
-
+ int devidx = mmc_get_devidx(md->disk);
blk_cleanup_queue(md->queue.queue);
__clear_bit(devidx, dev_use);
@@ -122,6 +137,38 @@ static void mmc_blk_put(struct mmc_blk_data *md)
mutex_unlock(&open_lock);
}
+static ssize_t force_ro_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ int ret;
+ struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
+
+ ret = snprintf(buf, PAGE_SIZE, "%d",
+ get_disk_ro(dev_to_disk(dev)) ^
+ md->read_only);
+ mmc_blk_put(md);
+ return ret;
+}
+
+static ssize_t force_ro_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int ret;
+ char *end;
+ struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
+ unsigned long set = simple_strtoul(buf, &end, 0);
+ if (end == buf) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ set_disk_ro(dev_to_disk(dev), set || md->read_only);
+ ret = count;
+out:
+ mmc_blk_put(md);
+ return ret;
+}
+
static int mmc_blk_open(struct block_device *bdev, fmode_t mode)
{
struct mmc_blk_data *md = mmc_blk_get(bdev->bd_disk);
@@ -176,6 +223,29 @@ struct mmc_blk_request {
struct mmc_data data;
};
+static inline int mmc_blk_part_switch(struct mmc_card *card,
+ struct mmc_blk_data *md)
+{
+ int ret;
+ struct mmc_blk_data *main_md = mmc_get_drvdata(card);
+ if (main_md->part_curr == md->part_type)
+ return 0;
+
+ if (mmc_card_mmc(card)) {
+ card->ext_csd.part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
+ card->ext_csd.part_config |= md->part_type;
+
+ ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_PART_CONFIG, card->ext_csd.part_config,
+ card->ext_csd.part_time);
+ if (ret)
+ return ret;
+}
+
+ main_md->part_curr = md->part_type;
+ return 0;
+}
+
static u32 mmc_sd_num_wr_blocks(struct mmc_card *card)
{
int err;
@@ -620,6 +690,11 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
struct mmc_card *card = md->queue.card;
mmc_claim_host(card->host);
+ ret = mmc_blk_part_switch(card, md);
+ if (ret) {
+ ret = 0;
+ goto out;
+ }
if (req->cmd_flags & REQ_DISCARD) {
if (req->cmd_flags & REQ_SECURE)
@@ -632,6 +707,7 @@ static int mmc_blk_issue_rq(struct mmc_queue *mq, struct request *req)
ret = mmc_blk_issue_rw_rq(mq, req);
}
+out:
mmc_release_host(card->host);
return ret;
}
@@ -642,7 +718,11 @@ static inline int mmc_blk_readonly(struct mmc_card *card)
!(card->csd.cmdclass & CCC_BLOCK_WRITE);
}
-static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
+static struct mmc_blk_data *mmc_blk_alloc_req(struct mmc_card *card,
+ struct device *parent,
+ sector_t size,
+ bool default_ro,
+ const char *subname)
{
struct mmc_blk_data *md;
int devidx, ret;
@@ -658,7 +738,6 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
goto out;
}
-
/*
* Set the read-only status based on the supported commands
* and the write protect switch.
@@ -672,6 +751,7 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
}
spin_lock_init(&md->lock);
+ INIT_LIST_HEAD(&md->part);
md->usage = 1;
ret = mmc_init_queue(&md->queue, card, &md->lock);
@@ -686,8 +766,8 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
md->disk->fops = &mmc_bdops;
md->disk->private_data = md;
md->disk->queue = md->queue.queue;
- md->disk->driverfs_dev = &card->dev;
- set_disk_ro(md->disk, md->read_only);
+ md->disk->driverfs_dev = parent;
+ set_disk_ro(md->disk, md->read_only || default_ro);
if (REL_WRITES_SUPPORTED(card))
blk_queue_flush(md->queue.queue, REQ_FLUSH | REQ_FUA);
@@ -703,33 +783,97 @@ static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
* messages to tell when the card is present.
*/
- snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
- "mmcblk%d", devidx);
+ if (subname)
+ snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
+ "mmcblk%d%s",
+ mmc_get_devidx(dev_to_disk(parent)), subname);
+ else
+ snprintf(md->disk->disk_name, sizeof(md->disk->disk_name),
+ "mmcblk%d", devidx);
blk_queue_logical_block_size(md->queue.queue, 512);
+ set_capacity(md->disk, size);
+ return md;
+
+ err_putdisk:
+ put_disk(md->disk);
+ err_kfree:
+ kfree(md);
+ out:
+ return ERR_PTR(ret);
+}
+
+static struct mmc_blk_data *mmc_blk_alloc(struct mmc_card *card)
+{
+ sector_t size;
+ struct mmc_blk_data *md;
if (!mmc_card_sd(card) && mmc_card_blockaddr(card)) {
/*
* The EXT_CSD sector count is in number or 512 byte
* sectors.
*/
- set_capacity(md->disk, card->ext_csd.sectors);
+ size = card->ext_csd.sectors;
} else {
/*
* The CSD capacity field is in units of read_blkbits.
* set_capacity takes units of 512 bytes.
*/
- set_capacity(md->disk,
- card->csd.capacity << (card->csd.read_blkbits - 9));
+ size = card->csd.capacity << (card->csd.read_blkbits - 9);
}
+
+ md = mmc_blk_alloc_req(card, &card->dev, size, false, NULL);
return md;
+}
- err_putdisk:
- put_disk(md->disk);
- err_kfree:
- kfree(md);
- out:
- return ERR_PTR(ret);
+static int mmc_blk_alloc_part(struct mmc_card *card,
+ struct mmc_blk_data *md,
+ unsigned int part_type,
+ sector_t size,
+ bool default_ro,
+ const char *subname)
+{
+ char cap_str[10];
+ struct mmc_blk_data *part_md;
+
+ part_md = mmc_blk_alloc_req(card, disk_to_dev(md->disk), size, default_ro,
+ subname);
+ if (IS_ERR(part_md))
+ return PTR_ERR(part_md);
+ part_md->part_type = part_type;
+ list_add(&part_md->part, &md->part);
+
+ string_get_size((u64)get_capacity(part_md->disk) << 9, STRING_UNITS_2,
+ cap_str, sizeof(cap_str));
+ printk(KERN_INFO "%s: %s %s partition %u %s\n",
+ part_md->disk->disk_name, mmc_card_id(card),
+ mmc_card_name(card), part_md->part_type, cap_str);
+ return 0;
+}
+
+static int mmc_blk_alloc_parts(struct mmc_card *card, struct mmc_blk_data *md)
+{
+ int 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;
+ }
+
+ return ret;
}
static int
@@ -750,9 +894,54 @@ mmc_blk_set_blksize(struct mmc_blk_data *md, struct mmc_card *card)
return 0;
}
+static void mmc_blk_remove_req(struct mmc_blk_data *md)
+{
+ if (md) {
+ if (md->disk->flags & GENHD_FL_UP) {
+ device_remove_file(disk_to_dev(md->disk), &md->force_ro);
+
+ /* Stop new requests from getting into the queue */
+ del_gendisk(md->disk);
+ }
+
+ /* Then flush out any already in there */
+ mmc_cleanup_queue(&md->queue);
+ mmc_blk_put(md);
+ }
+}
+
+static void mmc_blk_remove_parts(struct mmc_card *card,
+ struct mmc_blk_data *md)
+{
+ struct list_head *pos, *q;
+ struct mmc_blk_data *part_md;
+
+ list_for_each_safe(pos, q, &md->part) {
+ part_md = list_entry(pos, struct mmc_blk_data, part);
+ list_del(pos);
+ mmc_blk_remove_req(part_md);
+ }
+}
+
+static int mmc_add_disk(struct mmc_blk_data *md)
+{
+ int ret;
+
+ add_disk(md->disk);
+ md->force_ro.show = force_ro_show;
+ md->force_ro.store = force_ro_store;
+ md->force_ro.attr.name = "force_ro";
+ md->force_ro.attr.mode = S_IRUGO | S_IWUSR;
+ ret = device_create_file(disk_to_dev(md->disk), &md->force_ro);
+ if (ret)
+ del_gendisk(md->disk);
+
+ return ret;
+}
+
static int mmc_blk_probe(struct mmc_card *card)
{
- struct mmc_blk_data *md;
+ struct mmc_blk_data *md, *part_md;
int err;
char cap_str[10];
@@ -776,14 +965,22 @@ static int mmc_blk_probe(struct mmc_card *card)
md->disk->disk_name, mmc_card_id(card), mmc_card_name(card),
cap_str, md->read_only ? "(ro)" : "");
+ if (mmc_blk_alloc_parts(card, md))
+ goto out;
+
mmc_set_drvdata(card, md);
- add_disk(md->disk);
+ if (mmc_add_disk(md))
+ goto out;
+
+ list_for_each_entry(part_md, &md->part, part) {
+ if (mmc_add_disk(part_md))
+ goto out;
+ }
return 0;
out:
- mmc_cleanup_queue(&md->queue);
- mmc_blk_put(md);
-
+ mmc_blk_remove_parts(card, md);
+ mmc_blk_remove_req(md);
return err;
}
@@ -791,36 +988,43 @@ static void mmc_blk_remove(struct mmc_card *card)
{
struct mmc_blk_data *md = mmc_get_drvdata(card);
- if (md) {
- /* Stop new requests from getting into the queue */
- del_gendisk(md->disk);
-
- /* Then flush out any already in there */
- mmc_cleanup_queue(&md->queue);
-
- mmc_blk_put(md);
- }
+ mmc_blk_remove_parts(card, md);
+ mmc_blk_remove_req(md);
mmc_set_drvdata(card, NULL);
}
#ifdef CONFIG_PM
static int mmc_blk_suspend(struct mmc_card *card, pm_message_t state)
{
+ struct mmc_blk_data *part_md;
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
mmc_queue_suspend(&md->queue);
+ list_for_each_entry(part_md, &md->part, part) {
+ mmc_queue_suspend(&part_md->queue);
+ }
}
return 0;
}
static int mmc_blk_resume(struct mmc_card *card)
{
+ struct mmc_blk_data *part_md;
struct mmc_blk_data *md = mmc_get_drvdata(card);
if (md) {
mmc_blk_set_blksize(md, card);
+
+ /*
+ * Resume involves the card going into idle state,
+ * so current partition is always the main one.
+ */
+ md->part_curr = md->part_type;
mmc_queue_resume(&md->queue);
+ list_for_each_entry(part_md, &md->part, part) {
+ mmc_queue_resume(&part_md->queue);
+ }
}
return 0;
}
@@ -288,7 +288,10 @@ static int mmc_read_ext_csd(struct mmc_card *card)
if (card->ext_csd.rev >= 3) {
u8 sa_shift = ext_csd[EXT_CSD_S_A_TIMEOUT];
- card->ext_csd.bootconfig = ext_csd[EXT_CSD_BOOT_CONFIG];
+ card->ext_csd.part_config = ext_csd[EXT_CSD_PART_CONFIG];
+
+ /* EXT_CSD value is in units of 10ms, but we store in ms */
+ card->ext_csd.part_time = 10 * ext_csd[EXT_CSD_PART_SWITCH_TIME];
/* Sleep / awake timeout in 100ns units */
if (sa_shift > 0 && sa_shift <= 0x17)
@@ -302,6 +305,12 @@ static int mmc_read_ext_csd(struct mmc_card *card)
ext_csd[EXT_CSD_HC_ERASE_GRP_SIZE] << 10;
card->ext_csd.rel_sectors = ext_csd[EXT_CSD_REL_WR_SEC_C];
+
+ /*
+ * 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 (card->ext_csd.rev >= 4) {
@@ -576,10 +585,13 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
/*
* Ensure eMMC user default partition is enabled
*/
- if (card->ext_csd.bootconfig & 0x7) {
- card->ext_csd.bootconfig &= ~0x7;
- mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_CONFIG,
- card->ext_csd.bootconfig, 0);
+ if (card->ext_csd.part_config & EXT_CSD_PART_CONFIG_ACC_MASK) {
+ card->ext_csd.part_config &= ~EXT_CSD_PART_CONFIG_ACC_MASK;
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_PART_CONFIG,
+ card->ext_csd.part_config,
+ card->ext_csd.part_time);
+ if (err && err != -EBADMSG)
+ goto free_card;
}
/*
@@ -48,7 +48,8 @@ struct mmc_ext_csd {
u8 sec_feature_support;
u8 rel_sectors;
u8 rel_param;
- u8 bootconfig;
+ u8 part_config;
+ unsigned int part_time; /* Units: ms */
unsigned int sa_timeout; /* Units: 100ns */
unsigned int hs_max_dtr;
unsigned int sectors;
@@ -61,6 +62,7 @@ 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 */
};
struct sd_scr {
@@ -257,19 +257,21 @@ struct _mmc_csd {
#define EXT_CSD_PARTITION_SUPPORT 160 /* RO */
#define EXT_CSD_WR_REL_PARAM 166 /* RO */
#define EXT_CSD_ERASE_GROUP_DEF 175 /* R/W */
-#define EXT_CSD_BOOT_CONFIG 179 /* R/W */
+#define EXT_CSD_PART_CONFIG 179 /* R/W */
#define EXT_CSD_ERASED_MEM_CONT 181 /* RO */
#define EXT_CSD_BUS_WIDTH 183 /* R/W */
#define EXT_CSD_HS_TIMING 185 /* R/W */
#define EXT_CSD_REV 192 /* RO */
#define EXT_CSD_STRUCTURE 194 /* RO */
#define EXT_CSD_CARD_TYPE 196 /* RO */
+#define EXT_CSD_PART_SWITCH_TIME 199 /* RO */
#define EXT_CSD_SEC_CNT 212 /* RO, 4 bytes */
#define EXT_CSD_S_A_TIMEOUT 217 /* RO */
#define EXT_CSD_REL_WR_SEC_C 222 /* RO */
#define EXT_CSD_HC_WP_GRP_SIZE 221 /* RO */
#define EXT_CSD_ERASE_TIMEOUT_MULT 223 /* RO */
#define EXT_CSD_HC_ERASE_GRP_SIZE 224 /* RO */
+#define EXT_CSD_BOOT_MULT 226 /* RO */
#define EXT_CSD_SEC_TRIM_MULT 229 /* RO */
#define EXT_CSD_SEC_ERASE_MULT 230 /* RO */
#define EXT_CSD_SEC_FEATURE_SUPPORT 231 /* RO */
@@ -281,6 +283,10 @@ struct _mmc_csd {
#define EXT_CSD_WR_REL_PARAM_EN (1<<2)
+#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_CMD_SET_NORMAL (1<<0)
#define EXT_CSD_CMD_SET_SECURE (1<<1)
#define EXT_CSD_CMD_SET_CPSECURE (1<<2)