of: Specify initrd location using 64-bit

On some PAE architectures, the entire range of physical memory could reside
outside the 32-bit limit.  These systems need the ability to specify the
initrd location using 64-bit numbers.

This patch globally modifies the early_init_dt_setup_initrd_arch() function to
use 64-bit numbers instead of the current unsigned long.

There has been quite a bit of debate about whether to use u64 or phys_addr_t.
It was concluded to stick to u64 to be consistent with rest of the device
tree code. As summarized by Geert, "The address to load the initrd is decided
by the bootloader/user and set at that point later in time. The dtb should not
be tied to the kernel you are booting"

More details on the discussion can be found here:
https://lkml.org/lkml/2013/6/20/690
https://lkml.org/lkml/2012/9/13/544

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Rob Herring <rob.herring@calxeda.com>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

1 files changed, 6 insertions, 4 deletions

diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c
index 6bb7cf2de556..3f473d158d79 100644
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -550,7 +550,8 @@ int __init of_flat_dt_match(unsigned long node, const char *const *compat)
  */
 void __init early_init_dt_check_for_initrd(unsigned long node)
 {
-        unsigned long start, end, len;
+        u64 start, end;
+        unsigned long len;
         __be32 *prop;
 
         pr_debug("Looking for initrd properties... ");
@@ -558,15 +559,16 @@ void __init early_init_dt_check_for_initrd(unsigned long node)
         prop = of_get_flat_dt_prop(node, "linux,initrd-start", &len);
         if (!prop)
                 return;
-        start = of_read_ulong(prop, len/4);
+        start = of_read_number(prop, len/4);
 
         prop = of_get_flat_dt_prop(node, "linux,initrd-end", &len);
         if (!prop)
                 return;
-        end = of_read_ulong(prop, len/4);
+        end = of_read_number(prop, len/4);
 
         early_init_dt_setup_initrd_arch(start, end);
-        pr_debug("initrd_start=0x%lx  initrd_end=0x%lx\n", start, end);
+        pr_debug("initrd_start=0x%llx  initrd_end=0x%llx\n",
+                 (unsigned long long)start, (unsigned long long)end);
 }
 #else
 inline void early_init_dt_check_for_initrd(unsigned long node)