libfdt: Simplify adjustment of values for local fixups
In a couple of places in fdt_overlay.c we need to adjust a phandle value
in a property (either a node's phandle itself or a reference) by some
delta. Currently this is done if a fairly convoluted way, open-coding
loading the value and handling of a non-aligned reference, and then using
fdt_setprop_inplace_partial() to replace the value. This becomes much
simpler if we use fdt_getprop_w() to get a writable pointer to the value
then we can just load/store it with fdt32_{ld,st}().
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
diff --git a/libfdt/fdt_overlay.c b/libfdt/fdt_overlay.c
index 5c0c398..7ec839a 100644
--- a/libfdt/fdt_overlay.c
+++ b/libfdt/fdt_overlay.c
@@ -101,26 +101,22 @@
static int overlay_phandle_add_offset(void *fdt, int node,
const char *name, uint32_t delta)
{
- const fdt32_t *val;
- uint32_t adj_val;
+ fdt32_t *valp, val;
int len;
- val = fdt_getprop(fdt, node, name, &len);
- if (!val)
+ valp = fdt_getprop_w(fdt, node, name, &len);
+ if (!valp)
return len;
- if (len != sizeof(*val))
+ if (len != sizeof(val))
return -FDT_ERR_BADPHANDLE;
- adj_val = fdt32_to_cpu(*val);
- if ((adj_val + delta) < adj_val)
+ val = fdt32_ld(valp);
+ if (val + delta < val || val + delta == (uint32_t)-1)
return -FDT_ERR_NOPHANDLES;
- adj_val += delta;
- if (adj_val == (uint32_t)-1)
- return -FDT_ERR_NOPHANDLES;
-
- return fdt_setprop_inplace_u32(fdt, node, name, adj_val);
+ fdt32_st(valp, val + delta);
+ return 0;
}
/**
@@ -213,8 +209,8 @@
fdt_for_each_property_offset(fixup_prop, fdto, fixup_node) {
const fdt32_t *fixup_val;
- const char *tree_val;
const char *name;
+ char *tree_val;
int fixup_len;
int tree_len;
int i;
@@ -228,7 +224,7 @@
return -FDT_ERR_BADOVERLAY;
fixup_len /= sizeof(uint32_t);
- tree_val = fdt_getprop(fdto, tree_node, name, &tree_len);
+ tree_val = fdt_getprop_w(fdto, tree_node, name, &tree_len);
if (!tree_val) {
if (tree_len == -FDT_ERR_NOTFOUND)
return -FDT_ERR_BADOVERLAY;
@@ -237,33 +233,15 @@
}
for (i = 0; i < fixup_len; i++) {
- fdt32_t adj_val;
- uint32_t poffset;
+ fdt32_t *refp;
- poffset = fdt32_to_cpu(fixup_val[i]);
+ refp = (fdt32_t *)(tree_val + fdt32_ld_(fixup_val + i));
/*
- * phandles to fixup can be unaligned.
- *
- * Use a memcpy for the architectures that do
- * not support unaligned accesses.
+ * phandles to fixup can be unaligned, so use
+ * fdt32_{ld,st}() to read/write them.
*/
- memcpy(&adj_val, tree_val + poffset, sizeof(adj_val));
-
- adj_val = cpu_to_fdt32(fdt32_to_cpu(adj_val) + delta);
-
- ret = fdt_setprop_inplace_namelen_partial(fdto,
- tree_node,
- name,
- strlen(name),
- poffset,
- &adj_val,
- sizeof(adj_val));
- if (ret == -FDT_ERR_NOSPACE)
- return -FDT_ERR_BADOVERLAY;
-
- if (ret)
- return ret;
+ fdt32_st(refp, fdt32_ld(refp) + delta);
}
}
