On Mon, Aug 22, 2016 at 09:24:04PM +0800, Chin Liang See wrote:
Hi Tom,
On Mon, 2016-08-22 at 08:22 -0400, Tom Rini wrote:
This series moves the CONFIG_SYS_CACHELINE_SIZE. First, in nearly all cases we are mirroring the values used by the Linux Kernel here. Also, so long as (and in this case, it is true) we implement flushes in hunks that are no larger than the smallest implementation (and given that we mirror the Linux Kernel, again we are fine) it is OK to align higher. The biggest changes here are that we always use 64 bytes for CPU_V7 even if for example the underlying core is only 32 bytes (this mirrors Linux). Second, we say ARM64 uses 64 bytes not 128 (as found in the Linux Kernel) as we do not need multi-platform support (to this degree) and only the Cavium ThunderX 88xx series has a use for such large alignment.
...
arch/arm/Kconfig | 27
...
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index aef901c3f448..e6d4a2043854 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -7,6 +7,7 @@ config SYS_ARCH
...
config CPU_V7 bool select HAS_VBAR select HAS_THUMB2
- select SYS_CACHE_SHIFT_6
CPU_V7 should use SYS_CACHE_SHIFT_5 which is 32 bytes cache lines.
No, some V7 are 32 and some are 64, for example Cortex-A8.