* [PATCH] arm64: Add FIX_HOLE to permanent fixed addresses
@ 2014-11-26 0:14 Laura Abbott
2014-11-26 11:32 ` Will Deacon
0 siblings, 1 reply; 2+ messages in thread
From: Laura Abbott @ 2014-11-26 0:14 UTC (permalink / raw)
To: linux-arm-kernel
Every other architecture with permanent fixed addresses has
FIX_HOLE as the first entry. This seems to be designed as a
debugging aid but there are a couple of side effects of not
having FIX_HOLE:
- If the first fixed address is 0, fix_to_virt -> virt_to_fix
triggers a BUG_ON for the virtual address being equal to
FIXADDR_TOP
- fix_to_virt may return a value outside of FIXADDR_START
and FIXADDR_TOP which may look like a bug to a developer.
Match up with other architectures and make everything clearer
by adding FIX_HOLE.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
---
arch/arm64/include/asm/fixmap.h | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
index 5f7bfe6..424a10f 100644
--- a/arch/arm64/include/asm/fixmap.h
+++ b/arch/arm64/include/asm/fixmap.h
@@ -31,6 +31,7 @@
*
*/
enum fixed_addresses {
+ FIX_HOLE,
FIX_EARLYCON_MEM_BASE,
__end_of_permanent_fixed_addresses,
--
Qualcomm Innovation Center, Inc.
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project
^ permalink raw reply related [flat|nested] 2+ messages in thread* [PATCH] arm64: Add FIX_HOLE to permanent fixed addresses
2014-11-26 0:14 [PATCH] arm64: Add FIX_HOLE to permanent fixed addresses Laura Abbott
@ 2014-11-26 11:32 ` Will Deacon
0 siblings, 0 replies; 2+ messages in thread
From: Will Deacon @ 2014-11-26 11:32 UTC (permalink / raw)
To: linux-arm-kernel
On Wed, Nov 26, 2014 at 12:14:16AM +0000, Laura Abbott wrote:
> Every other architecture with permanent fixed addresses has
> FIX_HOLE as the first entry. This seems to be designed as a
> debugging aid but there are a couple of side effects of not
> having FIX_HOLE:
>
> - If the first fixed address is 0, fix_to_virt -> virt_to_fix
> triggers a BUG_ON for the virtual address being equal to
> FIXADDR_TOP
> - fix_to_virt may return a value outside of FIXADDR_START
> and FIXADDR_TOP which may look like a bug to a developer.
>
> Match up with other architectures and make everything clearer
> by adding FIX_HOLE.
>
> Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
> ---
> arch/arm64/include/asm/fixmap.h | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
> index 5f7bfe6..424a10f 100644
> --- a/arch/arm64/include/asm/fixmap.h
> +++ b/arch/arm64/include/asm/fixmap.h
> @@ -31,6 +31,7 @@
> *
> */
> enum fixed_addresses {
> + FIX_HOLE,
> FIX_EARLYCON_MEM_BASE,
> __end_of_permanent_fixed_addresses,
Looks sensible to me, thanks.
Will
^ permalink raw reply [flat|nested] 2+ messages in thread
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