The current code only allows to automatically set root device on MTD partitions. Move the code to MTD core to allow to use it with all MTD devices. Signed-off-by: Gabor Juhos <juhosg@openwrt.org> SVN-Revision: 38643
		
			
				
	
	
		
			146 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			146 lines
		
	
	
		
			4.3 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
--- a/drivers/mtd/mtdpart.c
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+++ b/drivers/mtd/mtdpart.c
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@@ -35,6 +35,8 @@
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 #include "mtdcore.h"
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 #include "mtdsplit.h"
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+#define MTD_ERASE_PARTIAL	0x8000 /* partition only covers parts of an erase block */
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+
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 /* Our partition linked list */
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 static LIST_HEAD(mtd_partitions);
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 static DEFINE_MUTEX(mtd_partitions_mutex);
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@@ -231,13 +233,60 @@ static int part_erase(struct mtd_info *m
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 	struct mtd_part *part = PART(mtd);
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 	int ret;
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+
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+	instr->partial_start = false;
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+	if (mtd->flags & MTD_ERASE_PARTIAL) {
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+		size_t readlen = 0;
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+		u64 mtd_ofs;
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+
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+		instr->erase_buf = kmalloc(part->master->erasesize, GFP_ATOMIC);
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+		if (!instr->erase_buf)
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+			return -ENOMEM;
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+
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+		mtd_ofs = part->offset + instr->addr;
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+		instr->erase_buf_ofs = do_div(mtd_ofs, part->master->erasesize);
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+
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+		if (instr->erase_buf_ofs > 0) {
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+			instr->addr -= instr->erase_buf_ofs;
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+			ret = mtd_read(part->master,
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+				instr->addr + part->offset,
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+				part->master->erasesize,
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+				&readlen, instr->erase_buf);
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+
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+			instr->partial_start = true;
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+		} else {
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+			mtd_ofs = part->offset + part->mtd.size;
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+			instr->erase_buf_ofs = part->master->erasesize -
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+				do_div(mtd_ofs, part->master->erasesize);
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+
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+			if (instr->erase_buf_ofs > 0) {
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+				instr->len += instr->erase_buf_ofs;
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+				ret = mtd_read(part->master,
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+					part->offset + instr->addr +
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+					instr->len - part->master->erasesize,
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+					part->master->erasesize, &readlen,
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+					instr->erase_buf);
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+			} else {
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+				ret = 0;
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+			}
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+		}
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+		if (ret < 0) {
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+			kfree(instr->erase_buf);
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+			return ret;
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+		}
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+
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+	}
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+
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 	instr->addr += part->offset;
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 	ret = part->master->_erase(part->master, instr);
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 	if (ret) {
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 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
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 			instr->fail_addr -= part->offset;
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 		instr->addr -= part->offset;
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+		if (mtd->flags & MTD_ERASE_PARTIAL)
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+			kfree(instr->erase_buf);
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 	}
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+
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 	return ret;
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 }
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@@ -245,7 +294,25 @@ void mtd_erase_callback(struct erase_inf
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 {
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 	if (instr->mtd->_erase == part_erase) {
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 		struct mtd_part *part = PART(instr->mtd);
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+		size_t wrlen = 0;
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+		if (instr->mtd->flags & MTD_ERASE_PARTIAL) {
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+			if (instr->partial_start) {
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+				part->master->_write(part->master,
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+					instr->addr, instr->erase_buf_ofs,
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+					&wrlen, instr->erase_buf);
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+				instr->addr += instr->erase_buf_ofs;
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+			} else {
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+				instr->len -= instr->erase_buf_ofs;
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+				part->master->_write(part->master,
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+					instr->addr + instr->len,
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+					instr->erase_buf_ofs, &wrlen,
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+					instr->erase_buf +
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+					part->master->erasesize -
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+					instr->erase_buf_ofs);
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+			}
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+			kfree(instr->erase_buf);
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+		}
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 		if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
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 			instr->fail_addr -= part->offset;
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 		instr->addr -= part->offset;
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@@ -503,18 +570,24 @@ static struct mtd_part *allocate_partiti
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 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
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 	    mtd_mod_by_eb(slave->offset, &slave->mtd)) {
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 		/* Doesn't start on a boundary of major erase size */
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-		/* FIXME: Let it be writable if it is on a boundary of
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-		 * _minor_ erase size though */
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-		slave->mtd.flags &= ~MTD_WRITEABLE;
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-		printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
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-			part->name);
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+		slave->mtd.flags |= MTD_ERASE_PARTIAL;
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+		if (((u32) slave->mtd.size) > master->erasesize)
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+			slave->mtd.flags &= ~MTD_WRITEABLE;
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+		else
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+			slave->mtd.erasesize = slave->mtd.size;
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 	}
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 	if ((slave->mtd.flags & MTD_WRITEABLE) &&
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-	    mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
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-		slave->mtd.flags &= ~MTD_WRITEABLE;
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-		printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
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-			part->name);
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+	    mtd_mod_by_eb(slave->offset + slave->mtd.size, &slave->mtd)) {
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+		slave->mtd.flags |= MTD_ERASE_PARTIAL;
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+
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+		if ((u32) slave->mtd.size > master->erasesize)
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+			slave->mtd.flags &= ~MTD_WRITEABLE;
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+		else
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+			slave->mtd.erasesize = slave->mtd.size;
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 	}
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+	if ((slave->mtd.flags & (MTD_ERASE_PARTIAL|MTD_WRITEABLE)) == MTD_ERASE_PARTIAL)
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+		printk(KERN_WARNING"mtd: partition \"%s\" must either start or end on erase block boundary or be smaller than an erase block -- forcing read-only\n",
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+				part->name);
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 	slave->mtd.ecclayout = master->ecclayout;
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 	slave->mtd.ecc_strength = master->ecc_strength;
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--- a/include/linux/mtd/mtd.h
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+++ b/include/linux/mtd/mtd.h
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@@ -58,6 +58,10 @@ struct erase_info {
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 	u_long priv;
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 	u_char state;
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 	struct erase_info *next;
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+
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+	u8 *erase_buf;
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+	u32 erase_buf_ofs;
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+	bool partial_start;
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 };
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 struct mtd_erase_region_info {
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