mmc: boot partition ro lock support (add710ea) · Commits · 戴 / test

Documentation/mmc/mmc-dev-parts.txt

+13 −0

Original line number	Diff line number	Diff line
		@@ -25,3 +25,16 @@ echo 0 > /sys/block/mmcblkXbootY/force_ro
		To re-enable read-only access:

		echo 1 > /sys/block/mmcblkXbootY/force_ro

		The boot partitions can also be locked read only until the next power on,
		with:

		echo 1 > /sys/block/mmcblkXbootY/ro_lock_until_next_power_on

		This is a feature of the card and not of the kernel. If the card does
		not support boot partition locking, the file will not exist. If the
		feature has been disabled on the card, the file will be read-only.

		The boot partitions can also be locked permanently, but this feature is
		not accessible through sysfs in order to avoid accidental or malicious
		bricking.

drivers/mmc/card/block.c

+113 −8

Original line number	Diff line number	Diff line
		@@ -107,6 +107,8 @@ struct mmc_blk_data {
		*/
		unsigned int part_curr;
		struct device_attribute force_ro;
		struct device_attribute power_ro_lock;
		int area_type;
		};

		static DEFINE_MUTEX(open_lock);
		@@ -165,6 +167,70 @@ static void mmc_blk_put(struct mmc_blk_data *md)
		mutex_unlock(&open_lock);
		}

		static ssize_t power_ro_lock_show(struct device *dev,
		struct device_attribute attr, char buf)
		{
		int ret;
		struct mmc_blk_data *md = mmc_blk_get(dev_to_disk(dev));
		struct mmc_card *card = md->queue.card;
		int locked = 0;

		if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PERM_WP_EN)
		locked = 2;
		else if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PWR_WP_EN)
		locked = 1;

		ret = snprintf(buf, PAGE_SIZE, "%d\n", locked);

		return ret;
		}

		static ssize_t power_ro_lock_store(struct device *dev,
		struct device_attribute attr, const char buf, size_t count)
		{
		int ret;
		struct mmc_blk_data md, part_md;
		struct mmc_card *card;
		unsigned long set;

		if (kstrtoul(buf, 0, &set))
		return -EINVAL;

		if (set != 1)
		return count;

		md = mmc_blk_get(dev_to_disk(dev));
		card = md->queue.card;

		mmc_claim_host(card->host);

		ret = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL, EXT_CSD_BOOT_WP,
		card->ext_csd.boot_ro_lock \|
		EXT_CSD_BOOT_WP_B_PWR_WP_EN,
		card->ext_csd.part_time);
		if (ret)
		pr_err("%s: Locking boot partition ro until next power on failed: %d\n", md->disk->disk_name, ret);
		else
		card->ext_csd.boot_ro_lock \|= EXT_CSD_BOOT_WP_B_PWR_WP_EN;

		mmc_release_host(card->host);

		if (!ret) {
		pr_info("%s: Locking boot partition ro until next power on\n",
		md->disk->disk_name);
		set_disk_ro(md->disk, 1);

		list_for_each_entry(part_md, &md->part, part)
		if (part_md->area_type == MMC_BLK_DATA_AREA_BOOT) {
		pr_info("%s: Locking boot partition ro until next power on\n", part_md->disk->disk_name);
		set_disk_ro(part_md->disk, 1);
		}
		}

		mmc_blk_put(md);
		return count;
		}

		static ssize_t force_ro_show(struct device dev, struct device_attribute attr,
		char *buf)
		{
		@@ -1347,7 +1413,8 @@ 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)
		const char *subname,
		int area_type)
		{
		struct mmc_blk_data *md;
		int devidx, ret;
		@@ -1372,11 +1439,12 @@ static struct mmc_blk_data mmc_blk_alloc_req(struct mmc_card card,
		if (!subname) {
		md->name_idx = find_first_zero_bit(name_use, max_devices);
		__set_bit(md->name_idx, name_use);
		}
		else
		} else
		md->name_idx = ((struct mmc_blk_data *)
		dev_to_disk(parent)->private_data)->name_idx;

		md->area_type = area_type;

		/*
		* Set the read-only status based on the supported commands
		* and the write protect switch.
		@@ -1470,7 +1538,8 @@ static struct mmc_blk_data mmc_blk_alloc(struct mmc_card card)
		size = card->csd.capacity << (card->csd.read_blkbits - 9);
		}

		md = mmc_blk_alloc_req(card, &card->dev, size, false, NULL);
		md = mmc_blk_alloc_req(card, &card->dev, size, false, NULL,
		MMC_BLK_DATA_AREA_MAIN);
		return md;
		}

		@@ -1479,13 +1548,14 @@ static int mmc_blk_alloc_part(struct mmc_card *card,
		unsigned int part_type,
		sector_t size,
		bool default_ro,
		const char *subname)
		const char *subname,
		int area_type)
		{
		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);
		subname, area_type);
		if (IS_ERR(part_md))
		return PTR_ERR(part_md);
		part_md->part_type = part_type;
		@@ -1518,7 +1588,8 @@ static int mmc_blk_alloc_parts(struct mmc_card card, struct mmc_blk_data md)
		card->part[idx].part_cfg,
		card->part[idx].size >> 9,
		card->part[idx].force_ro,
		card->part[idx].name);
		card->part[idx].name,
		card->part[idx].area_type);
		if (ret)
		return ret;
		}
		@@ -1547,9 +1618,16 @@ mmc_blk_set_blksize(struct mmc_blk_data md, struct mmc_card card)

		static void mmc_blk_remove_req(struct mmc_blk_data *md)
		{
		struct mmc_card *card;

		if (md) {
		card = md->queue.card;
		if (md->disk->flags & GENHD_FL_UP) {
		device_remove_file(disk_to_dev(md->disk), &md->force_ro);
		if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
		card->ext_csd.boot_ro_lockable)
		device_remove_file(disk_to_dev(md->disk),
		&md->power_ro_lock);

		/* Stop new requests from getting into the queue */
		del_gendisk(md->disk);
		@@ -1578,6 +1656,7 @@ static void mmc_blk_remove_parts(struct mmc_card *card,
		static int mmc_add_disk(struct mmc_blk_data *md)
		{
		int ret;
		struct mmc_card *card = md->queue.card;

		add_disk(md->disk);
		md->force_ro.show = force_ro_show;
		@@ -1587,6 +1666,32 @@ static int mmc_add_disk(struct mmc_blk_data *md)
		md->force_ro.attr.mode = S_IRUGO \| S_IWUSR;
		ret = device_create_file(disk_to_dev(md->disk), &md->force_ro);
		if (ret)
		goto force_ro_fail;

		if ((md->area_type & MMC_BLK_DATA_AREA_BOOT) &&
		card->ext_csd.boot_ro_lockable) {
		mode_t mode;

		if (card->ext_csd.boot_ro_lock & EXT_CSD_BOOT_WP_B_PWR_WP_DIS)
		mode = S_IRUGO;
		else
		mode = S_IRUGO \| S_IWUSR;

		md->power_ro_lock.show = power_ro_lock_show;
		md->power_ro_lock.store = power_ro_lock_store;
		md->power_ro_lock.attr.mode = mode;
		md->power_ro_lock.attr.name =
		"ro_lock_until_next_power_on";
		ret = device_create_file(disk_to_dev(md->disk),
		&md->power_ro_lock);
		if (ret)
		goto power_ro_lock_fail;
		}
		return ret;

		power_ro_lock_fail:
		device_remove_file(disk_to_dev(md->disk), &md->force_ro);
		force_ro_fail:
		del_gendisk(md->disk);

		return ret;

drivers/mmc/core/mmc.c

+12 −2

Original line number	Diff line number	Diff line
		@@ -348,7 +348,8 @@ static int mmc_read_ext_csd(struct mmc_card card, u8 ext_csd)
		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);
		"boot%d", idx, true,
		MMC_BLK_DATA_AREA_BOOT);
		}
		}
		}
		@@ -435,7 +436,8 @@ static int mmc_read_ext_csd(struct mmc_card card, u8 ext_csd)
		hc_wp_grp_sz);
		mmc_part_add(card, part_size << 19,
		EXT_CSD_PART_CONFIG_ACC_GP0 + idx,
		"gp%d", idx, false);
		"gp%d", idx, false,
		MMC_BLK_DATA_AREA_GP);
		}
		}
		card->ext_csd.sec_trim_mult =
		@@ -446,6 +448,14 @@ static int mmc_read_ext_csd(struct mmc_card card, u8 ext_csd)
		ext_csd[EXT_CSD_SEC_FEATURE_SUPPORT];
		card->ext_csd.trim_timeout = 300 *
		ext_csd[EXT_CSD_TRIM_MULT];

		/*
		* Note that the call to mmc_part_add above defaults to read
		* only. If this default assumption is changed, the call must
		* take into account the value of boot_locked below.
		*/
		card->ext_csd.boot_ro_lock = ext_csd[EXT_CSD_BOOT_WP];
		card->ext_csd.boot_ro_lockable = true;
		}

		if (card->ext_csd.rev >= 5) {

include/linux/mmc/card.h

+9 −1

Original line number	Diff line number	Diff line
		@@ -71,6 +71,8 @@ struct mmc_ext_csd {
		bool hpi_en; /* HPI enablebit */
		bool hpi; /* HPI support bit */
		unsigned int hpi_cmd; /* cmd used as HPI */
		unsigned int boot_ro_lock; /* ro lock support */
		bool boot_ro_lockable;
		u8 raw_partition_support; /* 160 */
		u8 raw_erased_mem_count; /* 181 */
		u8 raw_ext_csd_structure; /* 194 */
		@@ -187,6 +189,10 @@ struct mmc_part {
		unsigned int part_cfg; /* partition type */
		char name[MAX_MMC_PART_NAME_LEN];
		bool force_ro; /* to make boot parts RO by default */
		unsigned int area_type;
		#define MMC_BLK_DATA_AREA_MAIN (1<<0)
		#define MMC_BLK_DATA_AREA_BOOT (1<<1)
		#define MMC_BLK_DATA_AREA_GP (1<<2)
		};

		/*
		@@ -265,12 +271,14 @@ struct mmc_card {
		* 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)
		unsigned int part_cfg, char *name, int idx, bool ro,
		int area_type)
		{
		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->part[card->nr_parts].area_type = area_type;
		card->nr_parts++;
		}

include/linux/mmc/mmc.h

+6 −0

Original line number	Diff line number	Diff line
		@@ -280,6 +280,7 @@ struct _mmc_csd {
		#define EXT_CSD_RST_N_FUNCTION 162 /* R/W */
		#define EXT_CSD_SANITIZE_START 165 /* W */
		#define EXT_CSD_WR_REL_PARAM 166 /* RO */
		#define EXT_CSD_BOOT_WP 173 /* R/W */
		#define EXT_CSD_ERASE_GROUP_DEF 175 /* R/W */
		#define EXT_CSD_PART_CONFIG 179 /* R/W */
		#define EXT_CSD_ERASED_MEM_CONT 181 /* RO */
		@@ -321,6 +322,11 @@ struct _mmc_csd {

		#define EXT_CSD_WR_REL_PARAM_EN (1<<2)

		#define EXT_CSD_BOOT_WP_B_PWR_WP_DIS (0x40)
		#define EXT_CSD_BOOT_WP_B_PERM_WP_DIS (0x10)
		#define EXT_CSD_BOOT_WP_B_PERM_WP_EN (0x04)
		#define EXT_CSD_BOOT_WP_B_PWR_WP_EN (0x01)

		#define EXT_CSD_PART_CONFIG_ACC_MASK (0x7)
		#define EXT_CSD_PART_CONFIG_ACC_BOOT0 (0x1)
		#define EXT_CSD_PART_CONFIG_ACC_GP0 (0x4)

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