4.4-stable review patch. If anyone has any objections, please let me know.
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From: Joakim Tjernlund joakim.tjernlund@transmode.se
commit 6510bbc88e3258631831ade49033537081950605 upstream.
Currently it is possible to read and/or write to suspend EB's. Writing /dev/mtdX or /dev/mtdblockX from several processes may break the flash state machine.
Signed-off-by: Joakim Tjernlund joakim.tjernlund@infinera.com Cc: stable@vger.kernel.org Reviewed-by: Richard Weinberger richard@nod.at Signed-off-by: Boris Brezillon boris.brezillon@bootlin.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/mtd/chips/cfi_cmdset_0001.c | 16 +++++++++++----- include/linux/mtd/flashchip.h | 1 + 2 files changed, 12 insertions(+), 5 deletions(-)
--- a/drivers/mtd/chips/cfi_cmdset_0001.c +++ b/drivers/mtd/chips/cfi_cmdset_0001.c @@ -825,21 +825,25 @@ static int chip_ready (struct map_info * (mode == FL_WRITING && (cfip->SuspendCmdSupport & 1)))) goto sleep;
+ /* Do not allow suspend iff read/write to EB address */ + if ((adr & chip->in_progress_block_mask) == + chip->in_progress_block_addr) + goto sleep;
/* Erase suspend */ - map_write(map, CMD(0xB0), adr); + map_write(map, CMD(0xB0), chip->in_progress_block_addr);
/* If the flash has finished erasing, then 'erase suspend' * appears to make some (28F320) flash devices switch to * 'read' mode. Make sure that we switch to 'read status' * mode so we get the right data. --rmk */ - map_write(map, CMD(0x70), adr); + map_write(map, CMD(0x70), chip->in_progress_block_addr); chip->oldstate = FL_ERASING; chip->state = FL_ERASE_SUSPENDING; chip->erase_suspended = 1; for (;;) { - status = map_read(map, adr); + status = map_read(map, chip->in_progress_block_addr); if (map_word_andequal(map, status, status_OK, status_OK)) break;
@@ -1035,8 +1039,8 @@ static void put_chip(struct map_info *ma sending the 0x70 (Read Status) command to an erasing chip and expecting it to be ignored, that's what we do. */ - map_write(map, CMD(0xd0), adr); - map_write(map, CMD(0x70), adr); + map_write(map, CMD(0xd0), chip->in_progress_block_addr); + map_write(map, CMD(0x70), chip->in_progress_block_addr); chip->oldstate = FL_READY; chip->state = FL_ERASING; break; @@ -1927,6 +1931,8 @@ static int __xipram do_erase_oneblock(st map_write(map, CMD(0xD0), adr); chip->state = FL_ERASING; chip->erase_suspended = 0; + chip->in_progress_block_addr = adr; + chip->in_progress_block_mask = ~(len - 1);
ret = INVAL_CACHE_AND_WAIT(map, chip, adr, adr, len, --- a/include/linux/mtd/flashchip.h +++ b/include/linux/mtd/flashchip.h @@ -85,6 +85,7 @@ struct flchip { unsigned int write_suspended:1; unsigned int erase_suspended:1; unsigned long in_progress_block_addr; + unsigned long in_progress_block_mask;
struct mutex mutex; wait_queue_head_t wq; /* Wait on here when we're waiting for the chip