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authorJeremy Kerr2013-04-24 08:26:30 +0200
committerBenjamin Herrenschmidt2013-06-20 08:55:11 +0200
commit0962e8004e97409072bb6caee7b3ba948a5fb93a (patch)
tree9fdf0269b2cb7a2ce2c1c36da33d1663ba4dce8f /arch/powerpc/kernel/prom.c
parentpowerpc/mm: Make mmap_64.c compile on 32bit powerpc (diff)
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powerpc/prom: Scan reserved-ranges node for memory reservations
Based on benh's proposal at https://lists.ozlabs.org/pipermail/linuxppc-dev/2012-September/101237.html, this change provides support for reserving memory from the reserved-ranges node at the root of the device tree. We just call memblock_reserve on these ranges for now. Signed-off-by: Jeremy Kerr <jk@ozlabs.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/prom.c')
-rw-r--r--arch/powerpc/kernel/prom.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 8b6f7a99cce2..9c753bc9885d 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -559,6 +559,33 @@ void __init early_init_dt_setup_initrd_arch(unsigned long start,
}
#endif
+static bool __init early_reserve_mem_dt(void)
+{
+ unsigned long i, len, dt_root;
+ const __be32 *prop;
+
+ dt_root = of_get_flat_dt_root();
+
+ prop = of_get_flat_dt_prop(dt_root, "reserved-ranges", &len);
+
+ if (!prop)
+ return false;
+
+ /* Each reserved range is an (address,size) pair, 2 cells each,
+ * totalling 4 cells per range. */
+ for (i = 0; i < len / (sizeof(*prop) * 4); i++) {
+ u64 base, size;
+
+ base = of_read_number(prop + (i * 4) + 0, 2);
+ size = of_read_number(prop + (i * 4) + 2, 2);
+
+ if (size)
+ memblock_reserve(base, size);
+ }
+
+ return true;
+}
+
static void __init early_reserve_mem(void)
{
u64 base, size;
@@ -574,6 +601,14 @@ static void __init early_reserve_mem(void)
self_size = initial_boot_params->totalsize;
memblock_reserve(self_base, self_size);
+ /*
+ * Try looking for reserved-regions property in the DT first; if
+ * it's present, it'll contain all of the necessary reservation
+ * info
+ */
+ if (early_reserve_mem_dt())
+ return;
+
#ifdef CONFIG_BLK_DEV_INITRD
/* then reserve the initrd, if any */
if (initrd_start && (initrd_end > initrd_start))