[PATCH v4 10/11] ARM: kernel: add support for cpu cache information

Stephen Boyd sboyd at codeaurora.org
Fri Sep 19 15:25:44 PDT 2014


On 09/03/14 10:00, Sudeep Holla wrote:
> From: Sudeep Holla <sudeep.holla at arm.com>
>
> This patch adds support for cacheinfo on ARM platforms.
>
> On ARMv7, the cache hierarchy can be identified through Cache Level ID
> register(CLIDR) while the cache geometry is provided by Cache Size ID
> register(CCSIDR).
>
> On architecture versions before ARMv7, CLIDR and CCSIDR is not
> implemented. The cache type register(CTR) provides both cache hierarchy
> and geometry if implemented. For implementations that doesn't support
> CTR, we need to list the probable value of CTR if it was implemented
> along with the cpuid for the sake of simplicity to handle them.
>
> Since the architecture doesn't provide any way of detecting the cpus
> sharing particular cache, device tree is used fo the same purpose.
> On non-DT platforms, first level caches are per-cpu while higher level
> caches are assumed system-wide.
>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> Cc: Russell King <linux at arm.linux.org.uk>
> Cc: Will Deacon <will.deacon at arm.com>
> Cc: linux-arm-kernel at lists.infradead.org
>

Tested-by: Stephen Boyd <sboyd at codeaurora.org>

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