From: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> Date: Mon, 6 Mar 2023 19:55:23 +0000 > > >> 2023年3月6日 14:28，Alexander Lobakin <aleksander.lobakin@xxxxxxxxx> 写道： >> >> From: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> >> Date: Sat, 4 Mar 2023 22:15:16 +0000 >> >>> Octeon has a different cache interface with traditional R4K one, >>> just opt-out this flag for octeon to avoid run R4K cache initialization >>> code accidentally. >>> >>> Also remove ISA level assumption for 4k cache. >>> >>> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> >>> --- >>> arch/mips/include/asm/cpu-features.h | 2 +- >>> arch/mips/kernel/cpu-probe.c | 2 ++ >>> 2 files changed, 3 insertions(+), 1 deletion(-) >>> >>> diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h >>> index c0983130a44c..c613426b0bfc 100644 >>> --- a/arch/mips/include/asm/cpu-features.h >>> +++ b/arch/mips/include/asm/cpu-features.h >>> @@ -118,7 +118,7 @@ >>> #define cpu_has_3k_cache __isa_lt_and_opt(1, MIPS_CPU_3K_CACHE) >>> #endif >>> #ifndef cpu_has_4k_cache >>> -#define cpu_has_4k_cache __isa_ge_or_opt(1, MIPS_CPU_4K_CACHE) >>> +#define cpu_has_4k_cache __opt(MIPS_CPU_4K_CACHE) >> >> This breaks compile-time optimization for this feature => hurts >> performance on non-Octeon machines. Could this be done some other way? >> E.g. could this be defined depending on >> CONFIG_SYS_HAS_CPU_OCTEON_WHATEVER? Via its own cpu-features.h or here, >> that's the second question. So that the platforms which 100% can't have >> this family of CPUs wouldn't get affected. > > Thanks for the comment. > > This feature is only checked once during boot and never checked at runtime so I think impact > should be negligible. Ah, didn't notice it's not used anywhere on hotpath. Just forgot that MIPS installs cache sync callbacks once at boot and then use them. > > Just don’t want to have another ifdef here :-) I'm not sure one ifdef would hurt, we probably need a third opinion here :D Maybe Thomas'. But I'm fine with the current implementation. > > > Thanks > - Jiaxun Thanks, Olek
