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authorDavid Howells <dhowells@redhat.com>2009-02-12 13:40:00 +0300
committerDavid Woodhouse <David.Woodhouse@intel.com>2009-03-24 12:00:19 +0300
commit402d326519c1a4859c527702383f4e60f606ef52 (patch)
treebeb302d56d7671d372ae73f2664feed2a5b1226d /drivers/mtd/devices/mtdram.c
parent9ce969082e490d0a5a81862b364337c93dc3482a (diff)
downloadlinux-402d326519c1a4859c527702383f4e60f606ef52.tar.xz
NOMMU: Present backing device capabilities for MTD chardevs
Present backing device capabilities for MTD character device files to allow NOMMU mmap to do direct mapping where possible. Signed-off-by: David Howells <dhowells@redhat.com> Tested-by: Bernd Schmidt <bernd.schmidt@analog.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'drivers/mtd/devices/mtdram.c')
-rw-r--r--drivers/mtd/devices/mtdram.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/mtd/devices/mtdram.c b/drivers/mtd/devices/mtdram.c
index 3aaca88847d3..fce5ff7589aa 100644
--- a/drivers/mtd/devices/mtdram.c
+++ b/drivers/mtd/devices/mtdram.c
@@ -65,6 +65,19 @@ static void ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
}
+/*
+ * Allow NOMMU mmap() to directly map the device (if not NULL)
+ * - return the address to which the offset maps
+ * - return -ENOSYS to indicate refusal to do the mapping
+ */
+static unsigned long ram_get_unmapped_area(struct mtd_info *mtd,
+ unsigned long len,
+ unsigned long offset,
+ unsigned long flags)
+{
+ return (unsigned long) mtd->priv + offset;
+}
+
static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
@@ -116,6 +129,7 @@ int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
mtd->erase = ram_erase;
mtd->point = ram_point;
mtd->unpoint = ram_unpoint;
+ mtd->get_unmapped_area = ram_get_unmapped_area;
mtd->read = ram_read;
mtd->write = ram_write;