openwrtv3/target/linux/generic/patches-3.13/411-mtd-partial_eraseblock_write.patch
Felix Fietkau 1d232f354a kernel: mtd: allow partial block erase
This fixes error erasing partial mtd partition which does not start on
eraseblock boundary and allows using fconfig to configure redboot on
devices such as the Gateworks Cambria.

Signed-off-by: Maciej Skrzypek <maciej.skrzypek@flytronic.pl>

SVN-Revision: 41733
2014-07-18 14:36:38 +00:00

146 lines
4.4 KiB
Diff

--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -35,6 +35,8 @@
#include "mtdcore.h"
#include "mtdsplit.h"
+#define MTD_ERASE_PARTIAL 0x8000 /* partition only covers parts of an erase block */
+
/* Our partition linked list */
static LIST_HEAD(mtd_partitions);
static DEFINE_MUTEX(mtd_partitions_mutex);
@@ -231,13 +233,61 @@ static int part_erase(struct mtd_info *m
struct mtd_part *part = PART(mtd);
int ret;
+
+ instr->partial_start = false;
+ if (mtd->flags & MTD_ERASE_PARTIAL) {
+ size_t readlen = 0;
+ u64 mtd_ofs;
+
+ instr->erase_buf = kmalloc(part->master->erasesize, GFP_ATOMIC);
+ if (!instr->erase_buf)
+ return -ENOMEM;
+
+ mtd_ofs = part->offset + instr->addr;
+ instr->erase_buf_ofs = do_div(mtd_ofs, part->master->erasesize);
+
+ if (instr->erase_buf_ofs > 0) {
+ instr->addr -= instr->erase_buf_ofs;
+ ret = mtd_read(part->master,
+ instr->addr + part->offset,
+ part->master->erasesize,
+ &readlen, instr->erase_buf);
+
+ instr->len += instr->erase_buf_ofs;
+ instr->partial_start = true;
+ } else {
+ mtd_ofs = part->offset + part->mtd.size;
+ instr->erase_buf_ofs = part->master->erasesize -
+ do_div(mtd_ofs, part->master->erasesize);
+
+ if (instr->erase_buf_ofs > 0) {
+ instr->len += instr->erase_buf_ofs;
+ ret = mtd_read(part->master,
+ part->offset + instr->addr +
+ instr->len - part->master->erasesize,
+ part->master->erasesize, &readlen,
+ instr->erase_buf);
+ } else {
+ ret = 0;
+ }
+ }
+ if (ret < 0) {
+ kfree(instr->erase_buf);
+ return ret;
+ }
+
+ }
+
instr->addr += part->offset;
ret = part->master->_erase(part->master, instr);
if (ret) {
if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr -= part->offset;
instr->addr -= part->offset;
+ if (mtd->flags & MTD_ERASE_PARTIAL)
+ kfree(instr->erase_buf);
}
+
return ret;
}
@@ -245,7 +295,25 @@ void mtd_erase_callback(struct erase_inf
{
if (instr->mtd->_erase == part_erase) {
struct mtd_part *part = PART(instr->mtd);
+ size_t wrlen = 0;
+ if (instr->mtd->flags & MTD_ERASE_PARTIAL) {
+ if (instr->partial_start) {
+ part->master->_write(part->master,
+ instr->addr, instr->erase_buf_ofs,
+ &wrlen, instr->erase_buf);
+ instr->addr += instr->erase_buf_ofs;
+ } else {
+ instr->len -= instr->erase_buf_ofs;
+ part->master->_write(part->master,
+ instr->addr + instr->len,
+ instr->erase_buf_ofs, &wrlen,
+ instr->erase_buf +
+ part->master->erasesize -
+ instr->erase_buf_ofs);
+ }
+ kfree(instr->erase_buf);
+ }
if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr -= part->offset;
instr->addr -= part->offset;
@@ -503,18 +571,24 @@ static struct mtd_part *allocate_partiti
if ((slave->mtd.flags & MTD_WRITEABLE) &&
mtd_mod_by_eb(slave->offset, &slave->mtd)) {
/* Doesn't start on a boundary of major erase size */
- /* FIXME: Let it be writable if it is on a boundary of
- * _minor_ erase size though */
- slave->mtd.flags &= ~MTD_WRITEABLE;
- printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
- part->name);
+ slave->mtd.flags |= MTD_ERASE_PARTIAL;
+ if (((u32) slave->mtd.size) > master->erasesize)
+ slave->mtd.flags &= ~MTD_WRITEABLE;
+ else
+ slave->mtd.erasesize = slave->mtd.size;
}
if ((slave->mtd.flags & MTD_WRITEABLE) &&
- mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
- slave->mtd.flags &= ~MTD_WRITEABLE;
- printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
- part->name);
+ mtd_mod_by_eb(slave->offset + slave->mtd.size, &slave->mtd)) {
+ slave->mtd.flags |= MTD_ERASE_PARTIAL;
+
+ if ((u32) slave->mtd.size > master->erasesize)
+ slave->mtd.flags &= ~MTD_WRITEABLE;
+ else
+ slave->mtd.erasesize = slave->mtd.size;
}
+ if ((slave->mtd.flags & (MTD_ERASE_PARTIAL|MTD_WRITEABLE)) == MTD_ERASE_PARTIAL)
+ 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",
+ part->name);
slave->mtd.ecclayout = master->ecclayout;
slave->mtd.ecc_step_size = master->ecc_step_size;
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -55,6 +55,10 @@ struct erase_info {
u_long priv;
u_char state;
struct erase_info *next;
+
+ u8 *erase_buf;
+ u32 erase_buf_ofs;
+ bool partial_start;
};
struct mtd_erase_region_info {