diff mbox

[v2] powerpc: Force page alignment for initrd

Message ID 522F24EF533FC546962ECFA2054FF777373072AB72@MAILSERVER2.cos.astekcorp.com (mailing list archive)
State Superseded
Headers show

Commit Message

Dave Carroll May 20, 2011, 11:23 p.m. UTC
When using 64K pages with a separate cpio rootfs, U-Boot will align the rootfs
on a 4K page boundary. When the memory is reserved, and subsequent early
memblock_alloc is called, it will allocate memory between the 64K page alignment
and reserved memory. When the reserved memory is subsequently freed, it is done
so by pages, causing the early memblock_alloc requests to be re-used, which in
my case, caused the device-tree to be clobbered.

This patch forces initrd to be kernel page aligned, to match the mechanism used
to free reserved memory.

Signed-off-by: Dave Carroll <dcarroll@astekcorp.com>
---
 arch/powerpc/kernel/prom.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

--
1.7.4

Comments

Milton Miller May 21, 2011, 10:36 a.m. UTC | #1
On Fri, 20 May 2011 about 13:23:36 -0000, Dave Carroll wrote:
> When using 64K pages with a separate cpio rootfs, U-Boot will align
> the rootfs on a 4K page boundary. When the memory is reserved, and
> subsequent early memblock_alloc is called, it will allocate memory
> between the 64K page alignment and reserved memory. When the reserved
> memory is subsequently freed, it is done so by pages, causing the
> early memblock_alloc requests to be re-used, which in my case, caused
> the device-tree to be clobbered.
> 
> This patch forces initrd to be kernel page aligned, to match the
> mechanism used to free reserved memory.

Actually it is only forcing the memory reserved for the initrd (its
not moving the contents nor filling the extra space).

> 
> @@ -555,7 +555,8 @@ static void __init early_reserve_mem(void)
>  #ifdef CONFIG_BLK_DEV_INITRD
>         /* then reserve the initrd, if any */
>         if (initrd_start && (initrd_end > initrd_start))
> -               memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
> +               memblock_reserve(_ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
> +                       PAGE_ALIGN(initrd_end) - _ALIGN_DOWN(initrd_start, PAGE_SIZE));

Please align up the end, then change free_initrd_mem (32 and 64 bit)
to do the same range extension.

Thanks,
milton
diff mbox

Patch

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 48aeb55..7e58f6b 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -555,7 +555,8 @@  static void __init early_reserve_mem(void)
 #ifdef CONFIG_BLK_DEV_INITRD
        /* then reserve the initrd, if any */
        if (initrd_start && (initrd_end > initrd_start))
-               memblock_reserve(__pa(initrd_start), initrd_end - initrd_start);
+               memblock_reserve(_ALIGN_DOWN(__pa(initrd_start), PAGE_SIZE),
+                       PAGE_ALIGN(initrd_end) - _ALIGN_DOWN(initrd_start, PAGE_SIZE));
 #endif /* CONFIG_BLK_DEV_INITRD */

 #ifdef CONFIG_PPC32