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>

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 {

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)