[ck] Re: [patch v2 2/6] x86/cpu: Remove redundant cpu_detect_cache_sizes() call

commit 283bab9809786cf41798512f5c1e97f4b679ba96 upstream. Both functions call init_intel_cacheinfo() which computes L2 and L3 cache sizes from CPUID(4). But then they also call cpu_detect_cache_sizes() a bit later which computes ->x86_tlbsize and L2 size from CPUID(80000006). However, the latter call is not needed because  - on these CPUs, CPUID(80000006).EBX for ->x86_tlbsize is reserved  - CPUID(80000006).ECX for the L2 size has the same result as CPUID(4) Therefore, remove the latter call to simplify the code.  [ bp: Rewrite commit message. ] Signed-off-by: Tony W Wang-oc <TonyWWang-oc(a)zhaoxin.com> Signed-off-by: Borislav Petkov <bp(a)suse.de> Link: https://lkml.kernel.org/r/1579075257-6985-1-git-send-email-TonyWWang-oc@zha… Signed-off-by: LeoLiu-oc <LeoLiu-oc(a)zhaoxin.com>

---  arch/x86/kernel/cpu/centaur.c | 2 --  arch/x86/kernel/cpu/zhaoxin.c | 2 --  2 files changed, 4 deletions(-) diff --git a/arch/x86/kernel/cpu/centaur.c b/arch/x86/kernel/cpu/centaur.c index 14433ff5b828..b98529e50d6f 100644 --- a/arch/x86/kernel/cpu/centaur.c +++ b/arch/x86/kernel/cpu/centaur.c @@ -71,8 +71,6 @@ static void init_c3(struct cpuinfo_x86 *c)          c->x86_cache_alignment = c->x86_clflush_size * 2;          set_cpu_cap(c, X86_FEATURE_REP_GOOD);      } - -    cpu_detect_cache_sizes(c);  }  enum { diff --git a/arch/x86/kernel/cpu/zhaoxin.c b/arch/x86/kernel/cpu/zhaoxin.c index 8e6f2f4b4afe..452fd0a6bc61 100644 --- a/arch/x86/kernel/cpu/zhaoxin.c +++ b/arch/x86/kernel/cpu/zhaoxin.c @@ -58,8 +58,6 @@ static void init_zhaoxin_cap(struct cpuinfo_x86 *c)      if (c->x86 >= 0x6)          set_cpu_cap(c, X86_FEATURE_REP_GOOD); - -    cpu_detect_cache_sizes(c);  }  static void early_init_zhaoxin(struct cpuinfo_x86 *c)