of/flattree: use callback to setup initrd from /chosen

At present, the fdt code sets the kernel-wide initrd_start and
initrd_end variables when parsing /chosen. On ARM, we only set these
once the bootmem has been reserved.

This change adds an arch hook to setup the initrd from the device
tree:

 void early_init_dt_setup_initrd_arch(unsigned long start,
				      unsigned long end);

The arch-specific code can then setup the initrd however it likes.

Compiled on powerpc, with CONFIG_BLK_DEV_INITRD=y and =n.

Signed-off-by: Jeremy Kerr <jeremy.kerr@canonical.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index e0f368f..40fce1c 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -510,6 +510,16 @@ void __init early_init_dt_add_memory_arch(u64 base, u64 size)
 	memstart_addr = min((u64)memstart_addr, base);
 }
 
+#ifdef CONFIG_BLK_DEV_INITRD
+void __init early_init_dt_setup_initrd_arch(unsigned long start,
+		unsigned long end)
+{
+	initrd_start = (unsigned long)__va(start);
+	initrd_end = (unsigned long)__va(end);
+	initrd_below_start_ok = 1;
+}
+#endif
+
 static void __init early_reserve_mem(void)
 {
 	u64 base, size;