diff mbox

[V3,2/8] mmc: lock: Add low level LOCK_UNLOCK command

Message ID 1432077074-8422-3-git-send-email-alcooperx@gmail.com (mailing list archive)
State New, archived
Headers show

Commit Message

Alan Cooper May 19, 2015, 11:11 p.m. UTC
Add support for the LOCK_UNLOCK command. This command can lock,
unlock, set password, clear password and force erase SD and
MMC cards.

Signed-off-by: Al Cooper <alcooperx@gmail.com>
---
 drivers/mmc/core/core.c    |   5 +-
 drivers/mmc/core/mmc_ops.c | 150 +++++++++++++++++++++++++++++++++++++++++++++
 drivers/mmc/core/mmc_ops.h |  13 ++++
 include/linux/mmc/card.h   |   5 ++
 4 files changed, 169 insertions(+), 4 deletions(-)
diff mbox

Patch

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index f7d7ad9..4b0d26e 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2716,11 +2716,8 @@  static int mmc_key_instantiate(struct key *key,
 	char *payload;
 
 	if (prep->datalen <= 0 || prep->datalen > MMC_PASSWORD_MAX ||
-	    !prep->data) {
-		pr_warn("Invalid data\n");
+	    !prep->data)
 		return  -EINVAL;
-	}
-
 	payload = kmalloc(prep->datalen, GFP_KERNEL);
 	if (!payload)
 		return -ENOMEM;
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 0ea042d..c15c285 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -13,6 +13,8 @@ 
 #include <linux/export.h>
 #include <linux/types.h>
 #include <linux/scatterlist.h>
+#include <linux/key.h>
+#include <linux/err.h>
 
 #include <linux/mmc/host.h>
 #include <linux/mmc/card.h>
@@ -783,3 +785,151 @@  int mmc_can_ext_csd(struct mmc_card *card)
 {
 	return (card && card->csd.mmca_vsn > CSD_SPEC_VER_3);
 }
+
+#ifdef CONFIG_MMC_LOCK
+/**
+ *	mmc_lock_unlock - send LOCK_UNLOCK command to a specific card.
+ *	@card: card to which the LOCK_UNLOCK command should be sent
+ *	@key: key containing the MMC password
+ *	@mode: LOCK_UNLOCK mode
+ *
+ */
+int mmc_lock_unlock(struct mmc_card *card, struct mmc_password *password,
+		    int mode)
+{
+	struct mmc_request mrq;
+	struct mmc_command cmd_sbl;
+	struct mmc_command cmd;
+	struct mmc_data data;
+	struct scatterlist sg;
+	unsigned long erase_timeout;
+	int err, data_size;
+	u8 *data_buf = NULL;
+
+	if (mmc_card_mmc(card)) {
+		/* Lock commands only work on the data partition, select it */
+		err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+				EXT_CSD_PART_CONFIG,
+				card->ext_csd.part_config &
+				~EXT_CSD_PART_CONFIG_ACC_MASK,
+				card->ext_csd.part_time);
+
+		if (err != 0)
+			pr_warn("%s: Data partition select failed.\n",
+				mmc_hostname(card->host));
+
+		/*
+		 * The MMC spec does not allow rounding up the data to 512
+		 * bytes like SD spec
+		 */
+		if (mode & MMC_LOCK_MODE_ERASE)
+			data_size = 4;
+		else
+			data_size = 2 + password->length;
+	} else {
+		/* Round up the size of the data block to 512 bytes for SD */
+		data_size = 512;
+	}
+	data_buf = kzalloc(data_size, GFP_KERNEL);
+	if (!data_buf)
+		return -ENOMEM;
+	data_buf[0] |= mode;
+	if (!(mode & MMC_LOCK_MODE_ERASE)) {
+		data_buf[1] = password->length;
+		memcpy(data_buf + 2, password->password, password->length);
+	}
+
+	memset(&cmd_sbl, 0, sizeof(struct mmc_command));
+	cmd_sbl.opcode = MMC_SET_BLOCKLEN;
+	cmd_sbl.arg = data_size;
+	cmd_sbl.flags = MMC_RSP_R1 | MMC_CMD_AC;
+	err = mmc_wait_for_cmd(card->host, &cmd_sbl, MMC_CMD_RETRIES);
+	if (err)
+		goto out;
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+	cmd.opcode = MMC_LOCK_UNLOCK;
+	cmd.arg = 0;
+	cmd.flags = MMC_RSP_R1 | MMC_CMD_ADTC;
+
+	memset(&data, 0, sizeof(struct mmc_data));
+	mmc_set_data_timeout(&data, card);
+	data.blksz = data_size;
+	data.blocks = 1;
+	data.flags = MMC_DATA_WRITE;
+	data.sg = &sg;
+	data.sg_len = 1;
+
+	memset(&mrq, 0, sizeof(struct mmc_request));
+	mrq.cmd = &cmd;
+	mrq.data = &data;
+
+	sg_init_one(&sg, data_buf, data_size);
+	mmc_wait_for_req(card->host, &mrq);
+	if (cmd.error) {
+		err = cmd.error;
+		goto out;
+	}
+	if (data.error) {
+		err = data.error;
+		goto out;
+	}
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+	cmd.opcode = MMC_SEND_STATUS;
+	cmd.arg = card->rca << 16;
+	cmd.flags = MMC_RSP_R1 | MMC_CMD_AC;
+
+	/* set timeout for forced erase operation to 3 min. (see MMC spec) */
+	erase_timeout = jiffies + 180 * HZ;
+	do {
+		/*
+		 * we cannot use "retries" here because the
+		 * R1_LOCK_UNLOCK_FAILED bit is cleared by subsequent reads to
+		 * the status register, hiding the error condition
+		 */
+		err = mmc_wait_for_cmd(card->host, &cmd, 0);
+		if (err)
+			break;
+		/* the other modes don't need timeout checking */
+		if (!(mode & MMC_LOCK_MODE_ERASE))
+			continue;
+		if (time_after(jiffies, erase_timeout) &&
+		    !(cmd.resp[0] & R1_READY_FOR_DATA)) {
+			dev_err(&card->dev, "forced erase timed out\n");
+			err = -ETIMEDOUT;
+			break;
+		}
+	} while (!(cmd.resp[0] & R1_READY_FOR_DATA));
+	if (cmd.resp[0] & R1_LOCK_UNLOCK_FAILED) {
+		dev_dbg(&card->dev, "LOCK_UNLOCK operation failed\n");
+		err = -EIO;
+	}
+	if (cmd.resp[0] & R1_CARD_IS_LOCKED)
+		mmc_card_set_locked(card);
+	else
+		mmc_card_clear_locked(card);
+
+out:
+	/* Restore Block Length to the default */
+	cmd_sbl.arg = 512;
+	err = mmc_wait_for_cmd(card->host, &cmd_sbl, MMC_CMD_RETRIES);
+	if (err)
+		pr_warn("%s: Error restoring Block Length.\n",
+			mmc_hostname(card->host));
+	if (mmc_card_mmc(card)) {
+
+		/* Restore the selected partition */
+		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 != 0)
+			pr_warn("%s: Data partition select failed.\n",
+				mmc_hostname(card->host));
+	}
+	kfree(data_buf);
+	return err;
+}
+#endif /* CONFIG_MMC_LOCK */
diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
index 6f4b00e..92c9790 100644
--- a/drivers/mmc/core/mmc_ops.h
+++ b/drivers/mmc/core/mmc_ops.h
@@ -12,6 +12,15 @@ 
 #ifndef _MMC_MMC_OPS_H
 #define _MMC_MMC_OPS_H
 
+/*
+ * MMC_LOCK_UNLOCK modes
+ */
+#define MMC_LOCK_MODE_ERASE	(1<<3)
+#define MMC_LOCK_MODE_LOCK	(1<<2)
+#define MMC_LOCK_MODE_UNLOCK	(0<<2)
+#define MMC_LOCK_MODE_CLR_PWD	(1<<1)
+#define MMC_LOCK_MODE_SET_PWD	(1<<0)
+
 int mmc_select_card(struct mmc_card *card);
 int mmc_deselect_cards(struct mmc_host *host);
 int mmc_set_dsr(struct mmc_host *host);
@@ -27,6 +36,10 @@  int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
 int mmc_bus_test(struct mmc_card *card, u8 bus_width);
 int mmc_send_hpi_cmd(struct mmc_card *card, u32 *status);
 int mmc_can_ext_csd(struct mmc_card *card);
+#ifdef CONFIG_MMC_LOCK
+int mmc_lock_unlock(struct mmc_card *card, struct mmc_password *password,
+		    int mode);
+#endif
 
 #endif
 
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 19f0175..0c510b4 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -262,6 +262,7 @@  struct mmc_card {
 #define MMC_CARD_REMOVED	(1<<4)		/* card has been removed */
 #define MMC_STATE_DOING_BKOPS	(1<<5)		/* card is doing BKOPS */
 #define MMC_STATE_SUSPENDED	(1<<6)		/* card is suspended */
+#define MMC_STATE_LOCKED	(1<<7)		/* card is currently locked */
 	unsigned int		quirks; 	/* card quirks */
 #define MMC_QUIRK_LENIENT_FN0	(1<<0)		/* allow SDIO FN0 writes outside of the VS CCCR range */
 #define MMC_QUIRK_BLKSZ_FOR_BYTE_MODE (1<<1)	/* use func->cur_blksize */
@@ -427,6 +428,8 @@  static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
 #define mmc_card_removed(c)	((c) && ((c)->state & MMC_CARD_REMOVED))
 #define mmc_card_doing_bkops(c)	((c)->state & MMC_STATE_DOING_BKOPS)
 #define mmc_card_suspended(c)	((c)->state & MMC_STATE_SUSPENDED)
+#define mmc_card_locked(c)	((c)->state & MMC_STATE_LOCKED)
+#define mmc_card_lockable(c)	((c)->csd.cmdclass & CCC_LOCK_CARD)
 
 #define mmc_card_set_present(c)	((c)->state |= MMC_STATE_PRESENT)
 #define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
@@ -437,6 +440,8 @@  static inline void __maybe_unused remove_quirk(struct mmc_card *card, int data)
 #define mmc_card_clr_doing_bkops(c)	((c)->state &= ~MMC_STATE_DOING_BKOPS)
 #define mmc_card_set_suspended(c) ((c)->state |= MMC_STATE_SUSPENDED)
 #define mmc_card_clr_suspended(c) ((c)->state &= ~MMC_STATE_SUSPENDED)
+#define mmc_card_set_locked(c)	((c)->state |= MMC_STATE_LOCKED)
+#define mmc_card_clear_locked(c) ((c)->state &= ~MMC_STATE_LOCKED)
 
 /*
  * Quirk add/remove for MMC products.