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x86/cpu: Remove redundant cpu_detect_cache_sizes() call 

mainline inclusion
from mainline-v5.5-rc1
commit <283bab9809786cf41798512f5c1e97f4b679ba96>
category: feature

-------------------

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@zhaoxin.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/1579075257-6985-1-git-send-email-TonyWWang-oc@zhaoxin.com

Signed-off-by: leoliu-oc <leoliu-oc@zhaoxin.com>
This commit is contained in:
leoliu-oc 2024-08-26 16:27:14 +08:00
parent 62982bda95
commit adbb2ac925
2 changed files with 0 additions and 4 deletions
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2
arch/x86/kernel/cpu/centaur.c
View File

@ -71,8 +71,6 @@ static void init_c3(struct cpuinfo_x86 *c)
c->x86_cache_alignment = c->x86_clflush_size * 2; c->x86_cache_alignment = c->x86_clflush_size * 2;
set_cpu_cap(c, X86_FEATURE_REP_GOOD); set_cpu_cap(c, X86_FEATURE_REP_GOOD);
} }
cpu_detect_cache_sizes(c);
} }
enum { enum {

2
arch/x86/kernel/cpu/zhaoxin.c
View File

@ -58,8 +58,6 @@ static void init_zhaoxin_cap(struct cpuinfo_x86 *c)
if (c->x86 >= 0x6) if (c->x86 >= 0x6)
set_cpu_cap(c, X86_FEATURE_REP_GOOD); set_cpu_cap(c, X86_FEATURE_REP_GOOD);
cpu_detect_cache_sizes(c);
} }
static void early_init_zhaoxin(struct cpuinfo_x86 *c) static void early_init_zhaoxin(struct cpuinfo_x86 *c)