[PATCH v2 0/7] ARM: Broadcom Brahma-B15 readahead cache support

Florian Fainelli f.fainelli at gmail.com
Mon Aug 14 09:23:50 PDT 2017



On 07/14/2017 03:11 PM, Florian Fainelli wrote:
> On 06/23/2017 10:52 AM, Florian Fainelli wrote:
>> Hi all,
>>
>> This patch series adds support for the Broadcom Brahma-B15 readahead cache.
>> I submitted that patch series a couple of years ago, and then slept on it so
>> here is another stab at it.
>>
>> Note that we did not implement this cache as a version of an outer cache
>> for several reasons:
>>
>> - we initially thought we needed to intercept flush_icache_all and
>>   flush_kern_cache_louis but upon further inspection we convinced ourselves
>>   this is no longer needed, still, flush_cache_all() needs special handling
>>   here and needs to be wrapped around
>>
>> - the outer cache does not allow differentiating a DMA transfer direction
>>   this is a readahead cache, so it does not participate in writes, flushing
>>   it during reads *and* writes kills the performance completely
>>
>> - finally, most operations that outer_cache cares about are on MVA, which
>>   is transparent to the readahead cache here
>>
>> Changes in v2:
>>
>> - clarify that the read-ahead caches does invalidates on writes (IOW) based
>>   on Russell's feedback
> 
> Any comments on this? Thank you.

Should I just go a ahead and queue these changes in Russell's patch tracker?

> 
>>
>> Florian Fainelli (7):
>>   ARM: v7: allow setting different cache functions
>>   ARM: Add Broadcom Brahma-B15 readahead cache support
>>   ARM: Hook B15 readahead cache functions based on processor
>>   ARM: B15: Add CPU hotplug awareness
>>   ARM: B15: Add suspend/resume hooks
>>   ARM: B15: Register reboot notifier for KEXEC
>>   MAINTAINERS: Update brcmstb entries to cover B15 code
>>
>>  MAINTAINERS                                   |   2 +
>>  arch/arm/include/asm/glue-cache.h             |   4 +
>>  arch/arm/include/asm/hardware/cache-b15-rac.h |  10 +
>>  arch/arm/mm/Kconfig                           |   8 +
>>  arch/arm/mm/Makefile                          |   1 +
>>  arch/arm/mm/cache-b15-rac.c                   | 360 ++++++++++++++++++++++++++
>>  arch/arm/mm/cache-v7.S                        |  21 ++
>>  arch/arm/mm/proc-v7.S                         |   6 +-
>>  include/linux/cpuhotplug.h                    |   2 +
>>  9 files changed, 411 insertions(+), 3 deletions(-)
>>  create mode 100644 arch/arm/include/asm/hardware/cache-b15-rac.h
>>  create mode 100644 arch/arm/mm/cache-b15-rac.c
>>
> 
> 

-- 
Florian



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