From 371a689f64b0da140c3bcd3f55305ffa1c3a58ef Mon Sep 17 00:00:00 2001 From: Andrei Warkentin Date: Mon, 11 Apr 2011 18:10:25 -0500 Subject: [PATCH] mmc: MMC boot partitions support. Allows device MMC boot partitions to be accessed. MMC partitions are treated effectively as separate block devices on the same MMC card. Signed-off-by: Andrei Warkentin Acked-by: Arnd Bergmann Signed-off-by: Chris Ball --- Documentation/mmc/00-INDEX | 2 + Documentation/mmc/mmc-dev-attrs.txt | 10 + Documentation/mmc/mmc-dev-parts.txt | 27 +++ drivers/mmc/card/block.c | 274 ++++++++++++++++++++++++---- drivers/mmc/core/mmc.c | 22 ++- include/linux/mmc/card.h | 4 +- include/linux/mmc/mmc.h | 8 +- 7 files changed, 305 insertions(+), 42 deletions(-) create mode 100644 Documentation/mmc/mmc-dev-parts.txt diff --git a/Documentation/mmc/00-INDEX b/Documentation/mmc/00-INDEX index fca586f5b853..93dd7a714075 100644 --- a/Documentation/mmc/00-INDEX +++ b/Documentation/mmc/00-INDEX @@ -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 diff --git a/Documentation/mmc/mmc-dev-attrs.txt b/Documentation/mmc/mmc-dev-attrs.txt index ff2bd685bced..8898a95b41e5 100644 --- a/Documentation/mmc/mmc-dev-attrs.txt +++ b/Documentation/mmc/mmc-dev-attrs.txt @@ -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 ============================ diff --git a/Documentation/mmc/mmc-dev-parts.txt b/Documentation/mmc/mmc-dev-parts.txt new file mode 100644 index 000000000000..2db28b8e662f --- /dev/null +++ b/Documentation/mmc/mmc-dev-parts.txt @@ -0,0 +1,27 @@ +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 disabled by default to reduce the chance of +accidental bricking. + +To enable write access to /dev/mmcblkXbootY, disable the forced read-only +access with: + +echo 0 > /sys/block/mmcblkXbootY/force_ro + +To re-enable read-only access: + +echo 1 > /sys/block/mmcblkXbootY/force_ro diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 3e9082b729ff..1e6bd910e79e 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -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; } diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index 396cb23625d2..a2c795e8f9dd 100644 --- a/drivers/mmc/core/mmc.c +++ b/drivers/mmc/core/mmc.c @@ -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; } /* diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h index 937f852cf01e..0c7a58b14343 100644 --- a/include/linux/mmc/card.h +++ b/include/linux/mmc/card.h @@ -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 { diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h index 390aa6eef676..373b2bf5e5b5 100644 --- a/include/linux/mmc/mmc.h +++ b/include/linux/mmc/mmc.h @@ -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) -- 2.20.1