From 3cff177fc2793a362d784c912f536e69a755925e Mon Sep 17 00:00:00 2001 From: Shivamurthy Shastri Date: Tue, 19 Sep 2023 13:33:20 +0200 Subject: mtd: map_ram: prevent use of point and unpoint when NO_XIP is set When the DT property no-unaligned-direct-access is set, map->phys is set to NO_XIP. With this property set, the flash should not be exposed directly to MTD users, since it cannot be mapped. map_ram() exposes the flash direct access unconditionally which leads to access errors (when the bus width does not match the RAM width). Therefore do not set point and unpoint when NO_XIP is set. Signed-off-by: Shivamurthy Shastri Reviewed-by: Benedikt Spranger Signed-off-by: Miquel Raynal Link: https://lore.kernel.org/linux-mtd/20230919113320.16953-1-shivamurthy.shastri@linutronix.de --- drivers/mtd/chips/map_ram.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers') diff --git a/drivers/mtd/chips/map_ram.c b/drivers/mtd/chips/map_ram.c index e8dd6496927e..f9d3e32ef8e9 100644 --- a/drivers/mtd/chips/map_ram.c +++ b/drivers/mtd/chips/map_ram.c @@ -70,12 +70,16 @@ static struct mtd_info *map_ram_probe(struct map_info *map) mtd->_read = mapram_read; mtd->_write = mapram_write; mtd->_panic_write = mapram_write; - mtd->_point = mapram_point; mtd->_sync = mapram_nop; - mtd->_unpoint = mapram_unpoint; mtd->flags = MTD_CAP_RAM; mtd->writesize = 1; + /* Disable direct access when NO_XIP is set */ + if (map->phys != NO_XIP) { + mtd->_point = mapram_point; + mtd->_unpoint = mapram_unpoint; + } + mtd->erasesize = PAGE_SIZE; while(mtd->size & (mtd->erasesize - 1)) mtd->erasesize >>= 1; -- cgit v1.2.3-58-ga151