ARM: OMAP2+: Detect incorrectly aligned GPMC base address

Each GPMC chip-select can be configured to map 16MB, 32MB, 64MB or 128MB
of address space. The physical base address where a chip-select starts
is also configurable and must be aligned on a boundary that is equal to
or greater than the size of the address space mapped bt the chip-select.
When enabling a GPMC chip-select, ensure that the base address is aligned
to the appropriate boundary.

Reported-by: Mark Jackson <mpfj-list@mimc.co.uk>
Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Tested-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>

1 files changed, 19 insertions, 3 deletions

diff --git a/arch/arm/mach-omap2/gpmc.c b/arch/arm/mach-omap2/gpmc.c
index c7bf6ddf04ed..5c22b5adaeb5 100644
--- a/arch/arm/mach-omap2/gpmc.c
+++ b/arch/arm/mach-omap2/gpmc.c
@@ -403,11 +403,18 @@ int gpmc_cs_set_timings(int cs, const struct gpmc_timings *t)
         return 0;
 }
 
-static void gpmc_cs_enable_mem(int cs, u32 base, u32 size)
+static int gpmc_cs_enable_mem(int cs, u32 base, u32 size)
 {
         u32 l;
         u32 mask;
 
+        /*
+         * Ensure that base address is aligned on a
+         * boundary equal to or greater than size.
+         */
+        if (base & (size - 1))
+                return -EINVAL;
+
         mask = (1 << GPMC_SECTION_SHIFT) - size;
         l = gpmc_cs_read_reg(cs, GPMC_CS_CONFIG7);
         l &= ~0x3f;
@@ -416,6 +423,8 @@ static void gpmc_cs_enable_mem(int cs, u32 base, u32 size)
         l |= ((mask >> GPMC_CHUNK_SHIFT) & 0x0f) << 8;
         l |= GPMC_CONFIG7_CSVALID;
         gpmc_cs_write_reg(cs, GPMC_CS_CONFIG7, l);
+
+        return 0;
 }
 
 static void gpmc_cs_disable_mem(int cs)
@@ -526,7 +535,9 @@ static int gpmc_cs_remap(int cs, u32 base)
         ret = gpmc_cs_insert_mem(cs, base, size);
         if (ret < 0)
                 return ret;
-        gpmc_cs_enable_mem(cs, base, size);
+        ret = gpmc_cs_enable_mem(cs, base, size);
+        if (ret < 0)
+                return ret;
 
         return 0;
 }
@@ -556,7 +567,12 @@ int gpmc_cs_request(int cs, unsigned long size, unsigned long *base)
         if (r < 0)
                 goto out;
 
-        gpmc_cs_enable_mem(cs, res->start, resource_size(res));
+        r = gpmc_cs_enable_mem(cs, res->start, resource_size(res));
+        if (r < 0) {
+                release_resource(res);
+                goto out;
+        }
+
         *base = res->start;
         gpmc_cs_set_reserved(cs, 1);
 out: