Add MMC password protection (lock/unlock) support V2

Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc.c
===================================================================
@@ -986,10 +986,15 @@ static void mmc_check_cards(struct mmc_h
 		cmd.flags = MMC_RSP_R1;
 
 		err = mmc_wait_for_cmd(host, &cmd, CMD_RETRIES);
-		if (err == MMC_ERR_NONE)
+		if (err != MMC_ERR_NONE) {
+			mmc_card_set_dead(card);
 			continue;
+		}
 
-		mmc_card_set_dead(card);
+		if (cmd.resp[0] & R1_CARD_IS_LOCKED)
+			mmc_card_set_locked(card);
+		else
+			card->state &= ~MMC_STATE_LOCKED;
 	}
 }
 

Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc_sysfs.c
===================================================================
@@ -16,6 +16,7 @@
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>
+#include <linux/mmc/protocol.h>
 
 #include "mmc.h"
 

@@ -72,10 +73,19 @@ static void mmc_release_card(struct devi
  * This currently matches any MMC driver to any MMC card - drivers
  * themselves make the decision whether to drive this card in their
  * probe method.  However, we force "bad" cards to fail.
+ *
+ * We also fail for all locked cards; drivers expect to be able to do
+ * block I/O still on probe(), which is not possible while the card is
+ * locked. Device probing must be triggered sometime later to make the
+ * card available to the block driver.
  */
 static int mmc_bus_match(struct device *dev, struct device_driver *drv)
 {
 	struct mmc_card *card = dev_to_mmc_card(dev);
+	if (mmc_card_lockable(card) && mmc_card_locked(card)) {
+		dev_dbg(&card->dev, "card is locked; binding is deferred\n");
+		return 0;
+	}
 	return !mmc_card_bad(card);
 }
 

Index: linux-2.6.15-rc4-omap1/include/linux/mmc/card.h
===================================================================
@@ -56,6 +56,7 @@ struct mmc_card {
 #define MMC_STATE_BAD		(1<<2)		/* unrecognised device */
 #define MMC_STATE_SDCARD	(1<<3)		/* is an SD card */
 #define MMC_STATE_READONLY	(1<<4)		/* card is read-only */
+#define MMC_STATE_LOCKED	(1<<5)		/* card is currently locked */
 	u32			raw_cid[4];	/* raw card CID */
 	u32			raw_csd[4];	/* raw card CSD */
 	u32			raw_scr[2];	/* raw card SCR */

@@ -69,12 +70,16 @@ struct mmc_card {
 #define mmc_card_bad(c)		((c)->state & MMC_STATE_BAD)
 #define mmc_card_sd(c)		((c)->state & MMC_STATE_SDCARD)
 #define mmc_card_readonly(c)	((c)->state & MMC_STATE_READONLY)
+#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_dead(c)	((c)->state |= MMC_STATE_DEAD)
 #define mmc_card_set_bad(c)	((c)->state |= MMC_STATE_BAD)
 #define mmc_card_set_sd(c)	((c)->state |= MMC_STATE_SDCARD)
 #define mmc_card_set_readonly(c) ((c)->state |= MMC_STATE_READONLY)
+#define mmc_card_set_locked(c)	((c)->state |= MMC_STATE_LOCKED)
 
 #define mmc_card_name(c)	((c)->cid.prod_name)
 #define mmc_card_id(c)		((c)->dev.bus_id)

Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc.c
===================================================================
@@ -4,6 +4,8 @@
  *  Copyright (C) 2003-2004 Russell King, All Rights Reserved.
  *  SD support Copyright (C) 2004 Ian Molton, All Rights Reserved.
  *  SD support Copyright (C) 2005 Pierre Ossman, All Rights Reserved.
+ *  MMC password protection (C) 2005 Instituto Nokia de Tecnologia (INdT),
+ *     All Rights Reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as

@@ -20,6 +22,7 @@
 #include <linux/err.h>
 #include <asm/scatterlist.h>
 #include <linux/scatterlist.h>
+#include <linux/key.h>
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>

@@ -1088,6 +1091,159 @@ static void mmc_setup(struct mmc_host *h
 		mmc_read_scrs(host);
 }
 
+static int pop(unsigned x)
+{
+	x = x - ((x >> 1) & 0x55555555);
+	x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
+	x = (x + (x >> 4)) & 0x0F0F0F0F;
+	x = x + (x >> 8);
+	x = x + (x >> 16);
+
+	return x & 0x0000003F;
+}
+
+static int ilog2(unsigned x)
+{
+	x = x | (x >> 1);
+	x = x | (x >> 2);
+	x = x | (x >> 4);
+	x = x | (x >> 8);
+	x = x | (x >> 16);
+
+	return pop(x) - 1;
+}
+
+/* Calculate the minimal blksz_bits to hold x bytes. The two math functions
+ * above are used to do the calculation.
+ *
+ * XXX There must be a simpler way to do this... */
+static inline int blksz_bits(unsigned x)
+{
+	return 1 + ilog2(x - 1);
+}
+
+/**
+ *	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 key *key, int mode)
+{
+	struct mmc_request mrq;
+	struct mmc_command cmd;
+	struct mmc_data data;
+	struct scatterlist sg;
+	struct mmc_key_payload *mpayload;
+	unsigned long erase_timeout;
+	int err, data_size;
+	u8 *data_buf;
+
+	mpayload = NULL;
+	data_size = 1;
+	if (mode != MMC_LOCK_MODE_ERASE) {
+		mpayload = rcu_dereference(key->payload.data);
+		data_size = 2 + mpayload->datalen;
+	}
+
+	data_buf = kmalloc(data_size, GFP_KERNEL);
+	if (!data_buf)
+		return -ENOMEM;
+	memset(data_buf, 0, data_size);
+
+	data_buf[0] = mode;
+	if (mode != MMC_LOCK_MODE_ERASE) {
+		data_buf[1] = mpayload->datalen;
+		memcpy(data_buf + 2, mpayload->data, mpayload->datalen);
+	}
+
+	err = mmc_card_claim_host(card);
+	if (err != MMC_ERR_NONE) {
+		mmc_card_set_dead(card);
+		goto out;
+	}
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+
+	cmd.opcode = MMC_SET_BLOCKLEN;
+	cmd.arg = data_size;
+	cmd.flags = MMC_RSP_R1;
+	err = mmc_wait_for_cmd(card->host, &cmd, CMD_RETRIES);
+	if (err != MMC_ERR_NONE) {
+		mmc_card_set_dead(card);
+		goto error;
+	}
+
+	memset(&cmd, 0, sizeof(struct mmc_command));
+
+	cmd.opcode = MMC_LOCK_UNLOCK;
+	cmd.arg = 0;
+	cmd.flags = MMC_RSP_R1B;
+
+	memset(&data, 0, sizeof(struct mmc_data));
+
+	data.timeout_ns = card->csd.tacc_ns * 10;
+	data.timeout_clks = card->csd.tacc_clks * 10;
+	data.blksz_bits = blksz_bits(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);
+	err = mmc_wait_for_req(card->host, &mrq);
+	if (err != MMC_ERR_NONE) {
+		mmc_card_set_dead(card);
+		goto error;
+	}
+
+        memset(&cmd, 0, sizeof(struct mmc_command));
+
+	cmd.opcode = MMC_SEND_STATUS;
+	cmd.arg = card->rca << 16;
+	cmd.flags = MMC_RSP_R1;
+
+	/* 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 != MMC_ERR_NONE)
+			break;
+		/* the other modes don't need timeout checking */
+		if (mode != MMC_LOCK_MODE_ERASE)
+			continue;
+		if (time_after(jiffies, erase_timeout)) {
+			dev_dbg(&card->dev, "forced erase timed out\n");
+			err = MMC_ERR_TIMEOUT;
+			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 = MMC_ERR_FAILED;
+	}
+
+error:
+	mmc_check_cards(card->host);
+	mmc_deselect_cards(card->host);
+	mmc_card_release_host(card);
+out:
+	kfree(data_buf);
+
+	return err;
+}
+
+EXPORT_SYMBOL(mmc_lock_unlock);
+
 
 /**
  *	mmc_detect_change - process change of state on a MMC socket

Index: linux-2.6.15-rc4-omap1/include/linux/mmc/card.h
===================================================================
@@ -109,4 +109,7 @@ static inline int mmc_card_claim_host(st
 
 #define mmc_card_release_host(c)	mmc_release_host((c)->host)
 
+struct key;
+extern int mmc_lock_unlock(struct mmc_card *card, struct key *key, int mode);
+
 #endif

Index: linux-2.6.15-rc4-omap1/include/linux/mmc/protocol.h
===================================================================
@@ -243,5 +243,13 @@ struct _mmc_csd {
 #define SD_BUS_WIDTH_1      0
 #define SD_BUS_WIDTH_4      2
 
+/*
+ * MMC_LOCK_UNLOCK modes
+ */
+#define MMC_LOCK_MODE_ERASE	(1<<3)
+#define MMC_LOCK_MODE_UNLOCK	(0<<2)
+#define MMC_LOCK_MODE_CLR_PWD	(1<<1)
+#define MMC_LOCK_MODE_SET_PWD	(1<<0)
+
 #endif  /* MMC_MMC_PROTOCOL_H */
 

Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc.h
===================================================================
@@ -18,4 +18,12 @@ struct mmc_host *mmc_alloc_host_sysfs(in
 int mmc_add_host_sysfs(struct mmc_host *host);
 void mmc_remove_host_sysfs(struct mmc_host *host);
 void mmc_free_host_sysfs(struct mmc_host *host);
+
+/* core-internal data */
+extern struct key_type mmc_key_type;
+struct mmc_key_payload {
+	struct rcu_head	rcu;		/* RCU destructor */
+	unsigned short	datalen;	/* length of this data */
+	char		data[0];	/* actual data */
+};
 #endif

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Index: linux-2.6.15-rc4-omap1/drivers/mmc/mmc_sysfs.c
===================================================================
@@ -16,6 +16,7 @@
 #include <linux/device.h>
 #include <linux/idr.h>
 #include <linux/key.h>
+#include <linux/err.h>
 
 #include <linux/mmc/card.h>
 #include <linux/mmc/host.h>

@@ -64,6 +65,58 @@ static struct device_attribute mmc_dev_a
 
 static struct device_attribute mmc_dev_attr_scr = MMC_ATTR_RO(scr);
 
+#ifdef	CONFIG_MMC_PASSWORDS
+
+static ssize_t
+mmc_lockable_show(struct device *dev, struct device_attribute *att, char *buf)
+{
+	struct mmc_card *card = dev_to_mmc_card(dev);
+
+	if (!mmc_card_lockable(card))
+		return sprintf(buf, "unlockable\n");
+	else
+		return sprintf(buf, "lockable, %slocked\n", mmc_card_locked(card) ?
+			"" : "un");
+}
+
+/*
+ * implement MMC password reset ("remove password") and forced erase ("forgot
+ * password").
+ */
+static ssize_t
+mmc_lockable_store(struct device *dev, struct device_attribute *att,
+	const char *data, size_t len)
+{
+	struct mmc_card *card = dev_to_mmc_card(dev);
+
+	if (!mmc_card_lockable(card))
+		return -EINVAL;
+
+	if (mmc_card_locked(card) && !strncmp(data, "erase", 5)) {
+		/* forced erase only works while card is locked */
+		mmc_lock_unlock(card, NULL, MMC_LOCK_MODE_ERASE);
+		return len;
+	} else if (!mmc_card_locked(card) && !strncmp(data, "remove", 6)) {
+		/* remove password only works while card is unlocked */
+		struct key *mmc_key = request_key(&mmc_key_type, "mmc:key", NULL);
+
+		if (!IS_ERR(mmc_key)) {
+			int err = mmc_lock_unlock(card, mmc_key, MMC_LOCK_MODE_CLR_PWD);
+			if (!err)
+				return len;
+		} else
+			dev_dbg(&card->dev, "request_key returned error %ld\n", PTR_ERR(mmc_key));
+	}
+
+	return -EINVAL;
+}
+
+static struct device_attribute mmc_dev_attr_lockable =
+	__ATTR(lockable, S_IWUSR | S_IRUGO,
+		 mmc_lockable_show, mmc_lockable_store);
+
+#endif
+
 
 static void mmc_release_card(struct device *dev)
 {

@@ -235,6 +288,13 @@ int mmc_register_card(struct mmc_card *c
 			if (ret)
 				device_del(&card->dev);
 		}
+#ifdef CONFIG_MMC_PASSWORDS
+		if (mmc_card_lockable(card)) {
+			ret = device_create_file(&card->dev, &mmc_dev_attr_lockable);
+			if (ret)
+				device_del(&card->dev);
+		}
+#endif
 	}
 	return ret;
 }

@@ -248,7 +308,10 @@ void mmc_remove_card(struct mmc_card *ca
 	if (mmc_card_present(card)) {
 		if (mmc_card_sd(card))
 			device_remove_file(&card->dev, &mmc_dev_attr_scr);
-
+#ifdef CONFIG_MMC_PASSWORDS
+		if (mmc_card_lockable(card))
+			device_remove_file(&card->dev, &mmc_dev_attr_lockable);
+#endif
 		device_del(&card->dev);
 	}
 

Index: linux-2.6.15-rc4-omap1/drivers/mmc/omap.c
===================================================================
@@ -889,8 +889,12 @@ mmc_omap_prepare_data(struct mmc_omap_ho
 		return;
 	}
 
-
-	block_size = 1 << data->blksz_bits;
+	/*  password protection: we need to send the exact block size to the
+	 *  card (password + 2), not a power of two */
+	if (req->cmd->opcode == MMC_LOCK_UNLOCK)
+		block_size = data->sg[0].length;
+	else
+		block_size = 1 << data->blksz_bits;
 
 	OMAP_MMC_WRITE(host->base, NBLK, data->blocks - 1);
 	OMAP_MMC_WRITE(host->base, BLEN, block_size - 1);