[SPAM] [PATCH 0/2] riscv: improve unaligned memory accesses

Chen Huang chenhuang5 at huawei.com
Wed Sep 15 19:54:03 PDT 2021


Like ARM,powerpc and m68K,some CPUs don't support the unaligned memory access,
offer this as an option that CPU can choose it depending on its own design. I will
send v2 soon.

在 2021/9/15 22:13, Jisheng Zhang 写道:
> On Mon, 13 Sep 2021 12:19:54 +0000
> Chen Huang <chenhuang5 at huawei.com> wrote:
> 
>> The RISCV ISA can support unaligned memory accesses, so the patchset
>> selects HAVE_EFFICIENT_UNALIGNED_ACCESS and supports DCACHE_WORD_ACCESS
> 
> NO, per the spec, "Even when misaligned loads and stores complete
> successfully, these accesses might run extremely slowly depending on the
> implementation". it's far away from "efficient"
> 
>> to improve the efficiency of unaligned memory accesses.
>>
>> Chen Huang (2):
>>   riscv: Kconfig: select HAVE_EFFICIENT_UNALIGNED_ACCESS
>>   riscv: Support DCACHE_WORD_ACCESS
>>
>>  arch/riscv/Kconfig                      |  2 ++
>>  arch/riscv/include/asm/word-at-a-time.h | 36 +++++++++++++++++++++++++
>>  2 files changed, 38 insertions(+)
>>
> 
> 
> .
> 



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