path: root/target/linux/mediatek/patches/0441-block2mtd_probe.patch

Index: linux-3.10.20/drivers/mtd/devices/block2mtd.c
===================================================================
--- linux-3.10.20.orig/drivers/mtd/devices/block2mtd.c
+++ linux-3.10.20/drivers/mtd/devices/block2mtd.c
@@ -7,6 +7,7 @@
  * Licence: GPL
  */
 #include <linux/module.h>
+#include <linux/delay.h>
 #include <linux/fs.h>
 #include <linux/blkdev.h>
 #include <linux/bio.h>
@@ -32,10 +33,18 @@ struct block2mtd_dev {
 };
 
 
+/* the mtd parsers we want to use */
+static const char * const block2mtd_probe_types[] = { "cmdlinepart", NULL };
+
+/* we can map a single or a list of partitions */
+enum {
+	B2M_SINGLE = 0,
+	B2M_PARSER,
+};
+
 /* Static info about the MTD, used in cleanup_module */
 static LIST_HEAD(blkmtd_device_list);
 
-
 static struct page *page_read(struct address_space *mapping, int index)
 {
 	return read_mapping_page(mapping, index, NULL);
@@ -211,14 +220,16 @@ static void block2mtd_free_device(struct
 
 
 /* FIXME: ensure that mtd->size % erase_size == 0 */
-static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname)
+static struct block2mtd_dev *add_device(char *devname, int erase_size, const char *mtdname, int timeout, int offset, int length, int mtdparts)
 {
 	const fmode_t mode = FMODE_READ | FMODE_WRITE | FMODE_EXCL;
-	struct block_device *bdev;
+	struct block_device *bdev = ERR_PTR(-ENODEV);
 	struct block2mtd_dev *dev;
 	struct mtd_partition *part;
 	char *name;
-
+#ifndef MODULE
+	int i;
+#endif
 	if (!devname)
 		return NULL;
 
@@ -228,15 +239,20 @@ static struct block2mtd_dev *add_device(
 
 	/* Get a handle on the device */
 	bdev = blkdev_get_by_path(devname, mode, dev);
+
 #ifndef MODULE
-	if (IS_ERR(bdev)) {
+	for (i = 0; IS_ERR(bdev) && i <= timeout; i++) {
+		dev_t devt;
 
-		/* We might not have rootfs mounted at this point. Try
-		   to resolve the device name by other means. */
+		if (i)
+			msleep(1000);
+		wait_for_device_probe();
+
+		devt = name_to_dev_t(devname);
+		if (!devt)
+			continue;
 
-		dev_t devt = name_to_dev_t(devname);
-		if (devt)
-			bdev = blkdev_get_by_dev(devt, mode, dev);
+		bdev = blkdev_get_by_dev(devt, mode, dev);
 	}
 #endif
 
@@ -251,6 +267,16 @@ static struct block2mtd_dev *add_device(
 		goto devinit_err;
 	}
 
+	if (length && (long)length % erase_size) {
+		pr_err("length must be a divisor of device size\n");
+		goto devinit_err;
+	}
+
+	if (offset && (long)offset % erase_size) {
+		pr_err("offset must be a divisor of device size\n");
+		goto devinit_err;
+	}
+
 	mutex_init(&dev->write_mutex);
 
 	/* Setup the MTD structure */
@@ -277,6 +303,7 @@ static struct block2mtd_dev *add_device(
 	dev->mtd.priv = dev;
 	dev->mtd.owner = THIS_MODULE;
 
+#if 0
 	part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
 	part->name = name;
 	part->offset = 0;
@@ -285,6 +312,31 @@ static struct block2mtd_dev *add_device(
 		/* Device didn't get added, so free the entry */
 		goto devinit_err;
 	}
+#else
+	if (mtdparts == B2M_PARSER) {
+		struct mtd_part_parser_data ppdata = { 0 };
+		if (mtd_device_parse_register(&dev->mtd, block2mtd_probe_types, &ppdata, NULL, 0)) {
+			/* Device didn't get added, so free the entry */
+			goto devinit_err;
+		}
+	} else {
+		part = kzalloc(sizeof(struct mtd_partition), GFP_KERNEL);
+		part->name = name;
+		if (offset) {
+			part->offset = 0;
+			if (length && offset + length <= dev->mtd.size)
+				part->size = length;
+			else
+				part->size = dev->mtd.size - part->offset;
+		} else {
+			part->size = dev->mtd.size;
+		}
+		if (mtd_device_register(&dev->mtd, part, 1)) {
+			/* Device didn't get added, so free the entry */
+			goto devinit_err;
+		}
+ 	}
+#endif
 	list_add(&dev->list, &blkmtd_device_list);
 	INFO("mtd%d: [%s] erase_size = %dKiB [%d]", dev->mtd.index,
 			mtdname, dev->mtd.erasesize >> 10, dev->mtd.erasesize);
@@ -354,17 +406,20 @@ static inline void kill_final_newline(ch
 
 #ifndef MODULE
 static int block2mtd_init_called = 0;
-static char block2mtd_paramline[80 + 12]; /* 80 for device, 12 for erase size */
+static char block2mtd_paramline[80 + 12 + 80 + 8]; /* 80 for device, 12 for erase size */
+static char block2mtdparts_paramline[80 + 12 + 80 + 8]; /* 80 for device, 12 for erase size */
+
 #endif
 
 
-static int block2mtd_setup2(const char *val)
+static int block2mtd_setup2(const char *val, int mtdparts)
 {
-	char buf[80 + 12 + 80]; /* 80 for device, 12 for erase size, 80 for name */
+	char buf[80 + 12 + 80 + 8 + 12 + 12]; /* 80 for device, 12 for erase size, 80 for name, 8 for timeout, 12 for offset, 12 for size  */
 	char *str = buf;
-	char *token[3];
+	char *token[6];
 	char *name;
 	size_t erase_size = PAGE_SIZE;
+	unsigned long timeout = 0, offset = 0, length = 0;
 	int i, ret;
 
 	if (strnlen(val, sizeof(buf)) >= sizeof(buf))
@@ -373,7 +428,7 @@ static int block2mtd_setup2(const char *
 	strcpy(str, val);
 	kill_final_newline(str);
 
-	for (i = 0; i < 3; i++)
+	for (i = 0; i < 6; i++)
 		token[i] = strsep(&str, ",");
 
 	if (str)
@@ -395,7 +450,16 @@ static int block2mtd_setup2(const char *
 	if (token[2] && (strlen(token[2]) + 1 > 80))
 		parse_err("mtd device name too long");
 
-	add_device(name, erase_size, token[2]);
+	if (token[3] && kstrtoul(token[3], 0, &timeout))
+		parse_err("invalid timeout");
+
+	if (token[4] && kstrtoul(token[4], 0, &offset))
+		pr_err("invalid offset\n");
+
+	if (token[5] && kstrtoul(token[5], 0, &length))
+		pr_err("invalid length\n");
+
+	add_device(name, erase_size, token[2], timeout, offset, length, mtdparts);
 
 	return 0;
 }
@@ -404,7 +468,7 @@ static int block2mtd_setup2(const char *
 static int block2mtd_setup(const char *val, struct kernel_param *kp)
 {
 #ifdef MODULE
-	return block2mtd_setup2(val);
+	return block2mtd_setup2(val, B2M_SINGLE);
 #else
 	/* If more parameters are later passed in via
 	   /sys/module/block2mtd/parameters/block2mtd
@@ -412,7 +476,7 @@ static int block2mtd_setup(const char *v
 	   we can parse the argument now. */
 
 	if (block2mtd_init_called)
-		return block2mtd_setup2(val);
+		return block2mtd_setup2(val, B2M_SINGLE);
 
 	/* During early boot stage, we only save the parameters
 	   here. We must parse them later: if the param passed
@@ -428,8 +492,38 @@ static int block2mtd_setup(const char *v
 }
 
 
+static int block2mtdparts_setup(const char *val, struct kernel_param *kp)
+{
+#ifdef MODULE
+	return block2mtd_setup2(val, B2M_PARSER);
+#else
+	/* If more parameters are later passed in via
+	   /sys/module/block2mtd/parameters/block2mtd
+	   and block2mtd_init() has already been called,
+	   we can parse the argument now. */
+
+	if (block2mtd_init_called)
+		return block2mtd_setup2(val, B2M_PARSER);
+
+	/* During early boot stage, we only save the parameters
+	   here. We must parse them later: if the param passed
+	   from kernel boot command line, block2mtd_setup() is
+	   called so early that it is not possible to resolve
+	   the device (even kmalloc() fails). Deter that work to
+	   block2mtd_setup2(). */
+
+	strlcpy(block2mtdparts_paramline, val, sizeof(block2mtdparts_paramline));
+
+	return 0;
+#endif
+}
+
+
 module_param_call(block2mtd, block2mtd_setup, NULL, NULL, 0200);
-MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>[,<name>]]\"");
+MODULE_PARM_DESC(block2mtd, "Device to use. \"block2mtd=<dev>[,<erasesize>[,<name>[,<timeout>]]]\"");
+
+module_param_call(block2mtdparts, block2mtdparts_setup, NULL, NULL, 0200);
+MODULE_PARM_DESC(block2mtdparts, "Device to use. \"block2mtdparts=<dev>[,<erasesize>[,<name>[,<timeout>]]]\"");
 
 static int __init block2mtd_init(void)
 {
@@ -437,7 +531,9 @@ static int __init block2mtd_init(void)
 
 #ifndef MODULE
 	if (strlen(block2mtd_paramline))
-		ret = block2mtd_setup2(block2mtd_paramline);
+		ret = block2mtd_setup2(block2mtd_paramline, B2M_SINGLE);
+	if (strlen(block2mtdparts_paramline))
+		ret = block2mtd_setup2(block2mtdparts_paramline, B2M_PARSER);
 	block2mtd_init_called = 1;
 #endif
 
@@ -462,7 +558,7 @@ static void block2mtd_exit(void)
 }
 
 
-module_init(block2mtd_init);
+late_initcall(block2mtd_init);
 module_exit(block2mtd_exit);
 
 MODULE_LICENSE("GPL");