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fdt: Fix alignment issue when reading 64-bits properties from fdt

The FDT specification [0] gives a requirement of aligning properties on
32-bits. Make sure that the compiler is aware of this constraint when
accessing 64-bits properties.

[0]: https://github.com/devicetree-org/devicetree-specification/blob/master/source/flattened-format.rst

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Jean-Jacques Hiblot 4 years ago
parent
commit
d60ae4c59d
4 changed files with 4 additions and 3 deletions
  1. 1 1
      common/fdt_support.c
  2. 1 1
      drivers/core/ofnode.c
  3. 1 0
      include/linux/libfdt_env.h
  4. 1 1
      lib/fdtdec.c

+ 1 - 1
common/fdt_support.c

@@ -1566,7 +1566,7 @@ static int fdt_read_prop(const fdt32_t *prop, int prop_len, int cell_off,
 			 uint64_t *val, int cells)
 {
 	const fdt32_t *prop32 = &prop[cell_off];
-	const fdt64_t *prop64 = (const fdt64_t *)&prop[cell_off];
+	const unaligned_fdt64_t *prop64 = (const fdt64_t *)&prop[cell_off];
 
 	if ((cell_off + cells) > prop_len)
 		return -FDT_ERR_NOSPACE;

+ 1 - 1
drivers/core/ofnode.c

@@ -57,7 +57,7 @@ int ofnode_read_s32_default(ofnode node, const char *propname, s32 def)
 
 int ofnode_read_u64(ofnode node, const char *propname, u64 *outp)
 {
-	const fdt64_t *cell;
+	const unaligned_fdt64_t *cell;
 	int len;
 
 	assert(ofnode_valid(node));

+ 1 - 0
include/linux/libfdt_env.h

@@ -16,6 +16,7 @@
 typedef __be16 fdt16_t;
 typedef __be32 fdt32_t;
 typedef __be64 fdt64_t;
+typedef __be64 unaligned_fdt64_t __aligned(4);
 
 #define fdt32_to_cpu(x) be32_to_cpu(x)
 #define cpu_to_fdt32(x) cpu_to_be32(x)

+ 1 - 1
lib/fdtdec.c

@@ -242,7 +242,7 @@ int fdtdec_get_pci_bar32(struct udevice *dev, struct fdt_pci_addr *addr,
 uint64_t fdtdec_get_uint64(const void *blob, int node, const char *prop_name,
 			   uint64_t default_val)
 {
-	const uint64_t *cell64;
+	const unaligned_fdt64_t *cell64;
 	int length;
 
 	cell64 = fdt_getprop(blob, node, prop_name, &length);