mtd: cfi: cmdset_0001: Do not allow read/write to suspend erase block.

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>

1 files changed, 11 insertions, 5 deletions

diff --git a/drivers/mtd/chips/cfi_cmdset_0001.c b/drivers/mtd/chips/cfi_cmdset_0001.c
index d4c07b85f18e..8833115fbc11 100644
--- a/drivers/mtd/chips/cfi_cmdset_0001.c
+++ b/drivers/mtd/chips/cfi_cmdset_0001.c
@@ -831,21 +831,25 @@ static int chip_ready (struct map_info *map, struct flchip *chip, unsigned long
                      (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;
 
@@ -1041,8 +1045,8 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
                    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;
@@ -1933,6 +1937,8 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
         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,