From d0788ce4924758249c9552c91cc33024d3434419 Mon Sep 17 00:00:00 2001 From: Stefan Roese Date: Fri, 17 Aug 2012 15:22:32 +0200 Subject: mtd: physmap_of: Add "no-unaligned-direct-access" DT property On some platforms (e.g. MPC5200) a direct 1:1 mapping may cause problems with JFFS2 usage, as the local bus (LPB) doesn't support unaligned accesses as implemented in the JFFS2 code via memcpy(). By defining "no-unaligned-direct-access", the flash will not be exposed directly to the MTD users (e.g. JFFS2) any more. Signed-off-by: Stefan Roese Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/maps/physmap_of.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'drivers/mtd/maps') diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c index 2e6fb6831d5..6f19acadb06 100644 --- a/drivers/mtd/maps/physmap_of.c +++ b/drivers/mtd/maps/physmap_of.c @@ -169,6 +169,7 @@ static int __devinit of_flash_probe(struct platform_device *dev) struct mtd_info **mtd_list = NULL; resource_size_t res_size; struct mtd_part_parser_data ppdata; + bool map_indirect; match = of_match_device(of_flash_match, &dev->dev); if (!match) @@ -192,6 +193,8 @@ static int __devinit of_flash_probe(struct platform_device *dev) } count /= reg_tuple_size; + map_indirect = of_property_read_bool(dp, "no-unaligned-direct-access"); + err = -ENOMEM; info = kzalloc(sizeof(struct of_flash) + sizeof(struct of_flash_list) * count, GFP_KERNEL); @@ -247,6 +250,17 @@ static int __devinit of_flash_probe(struct platform_device *dev) simple_map_init(&info->list[i].map); + /* + * On some platforms (e.g. MPC5200) a direct 1:1 mapping + * may cause problems with JFFS2 usage, as the local bus (LPB) + * doesn't support unaligned accesses as implemented in the + * JFFS2 code via memcpy(). By setting NO_XIP, the + * flash will not be exposed directly to the MTD users + * (e.g. JFFS2) any more. + */ + if (map_indirect) + info->list[i].map.phys = NO_XIP; + if (probe_type) { info->list[i].mtd = do_map_probe(probe_type, &info->list[i].map); -- cgit v1.2.3