* [PATCH v2] arm64: mm: use ubfm for dcache_line_size
@ 2014-01-20 5:00 Jingoo Han
2014-01-21 11:05 ` Will Deacon
0 siblings, 1 reply; 2+ messages in thread
From: Jingoo Han @ 2014-01-20 5:00 UTC (permalink / raw)
To: linux-arm-kernel
Use 'ubfm' for the bitfield move instruction; thus, single
instruction can be used instead of two instructions, when
getting the minimum D-cache line size from CTR_EL0 register.
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
---
Change since v1
- Remove unnecessary prefix '0x' from immediates, per Will Deacon
- Add '#' to immediates for consistency, per Ard Biesheuvel
arch/arm64/mm/proc-macros.S | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/arm64/mm/proc-macros.S b/arch/arm64/mm/proc-macros.S
index 8957b82..005d29e 100644
--- a/arch/arm64/mm/proc-macros.S
+++ b/arch/arm64/mm/proc-macros.S
@@ -38,8 +38,7 @@
*/
.macro dcache_line_size, reg, tmp
mrs \tmp, ctr_el0 // read CTR
- lsr \tmp, \tmp, #16
- and \tmp, \tmp, #0xf // cache line size encoding
+ ubfm \tmp, \tmp, #16, #19 // cache line size encoding
mov \reg, #4 // bytes per word
lsl \reg, \reg, \tmp // actual cache line size
.endm
--
1.7.10.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* [PATCH v2] arm64: mm: use ubfm for dcache_line_size
2014-01-20 5:00 [PATCH v2] arm64: mm: use ubfm for dcache_line_size Jingoo Han
@ 2014-01-21 11:05 ` Will Deacon
0 siblings, 0 replies; 2+ messages in thread
From: Will Deacon @ 2014-01-21 11:05 UTC (permalink / raw)
To: linux-arm-kernel
On Mon, Jan 20, 2014 at 05:00:21AM +0000, Jingoo Han wrote:
> Use 'ubfm' for the bitfield move instruction; thus, single
> instruction can be used instead of two instructions, when
> getting the minimum D-cache line size from CTR_EL0 register.
>
> Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Thanks,
Will
> ---
> Change since v1
> - Remove unnecessary prefix '0x' from immediates, per Will Deacon
> - Add '#' to immediates for consistency, per Ard Biesheuvel
>
> arch/arm64/mm/proc-macros.S | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/arch/arm64/mm/proc-macros.S b/arch/arm64/mm/proc-macros.S
> index 8957b82..005d29e 100644
> --- a/arch/arm64/mm/proc-macros.S
> +++ b/arch/arm64/mm/proc-macros.S
> @@ -38,8 +38,7 @@
> */
> .macro dcache_line_size, reg, tmp
> mrs \tmp, ctr_el0 // read CTR
> - lsr \tmp, \tmp, #16
> - and \tmp, \tmp, #0xf // cache line size encoding
> + ubfm \tmp, \tmp, #16, #19 // cache line size encoding
> mov \reg, #4 // bytes per word
> lsl \reg, \reg, \tmp // actual cache line size
> .endm
> --
> 1.7.10.4
>
>
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2014-01-21 11:05 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-01-20 5:00 [PATCH v2] arm64: mm: use ubfm for dcache_line_size Jingoo Han
2014-01-21 11:05 ` Will Deacon
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).