Commit 283bab98 authored Jan 15, 2020 by Tony W Wang-oc Committed by Borislav Petkov Jan 20, 2020

x86/cpu: Remove redundant cpu_detect_cache_sizes() call



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

parent bb02e2cb

arch/x86/kernel/cpu/centaur.c

+0 −2

Original line number	Diff line number	Diff line
		@@ -64,8 +64,6 @@ 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

+0 −2

Original line number	Diff line number	Diff line
		@@ -51,8 +51,6 @@ 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)

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