linux-kernel - [PATCH v1 4/4] x86, CPU: Preset default tlb_flushall

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Date:	Mon,  6 Aug 2012 19:00:39 +0200
From:	Borislav Petkov <bp@...64.org>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	Alex Shi <alex.shi@...el.com>, X86-ML <x86@...nel.org>,
	LKML <linux-kernel@...r.kernel.org>,
	Borislav Petkov <borislav.petkov@....com>
Subject: [PATCH v1 4/4] x86, CPU: Preset default tlb_flushall_shift on AMD

From: Borislav Petkov <borislav.petkov@....com>

Run the mprotect.c microbenchmark on all our families >= K8 and preset
the flushall shift variable accordingly.

Signed-off-by: Borislav Petkov <borislav.petkov@....com>
---
 arch/x86/kernel/cpu/amd.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index bcd200839c90..f7e98a2c0d12 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -737,6 +737,17 @@ static unsigned int __cpuinit amd_size_cache(struct cpuinfo_x86 *c,
 }
 #endif
 
+static void __cpuinit cpu_set_tlb_flushall_shift(struct cpuinfo_x86 *c)
+{
+	if (!cpu_has_invlpg)
+		return;
+
+	tlb_flushall_shift = 5;
+
+	if (c->x86 <= 0x11)
+		tlb_flushall_shift = 4;
+}
+
 static void __cpuinit cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
 {
 	u32 ebx, eax, ecx, edx;
@@ -788,6 +799,8 @@ static void __cpuinit cpu_detect_tlb_amd(struct cpuinfo_x86 *c)
 		tlb_lli_2m[ENTRIES] = eax & mask;
 
 	tlb_lli_4m[ENTRIES] = tlb_lli_2m[ENTRIES] >> 1;
+
+	cpu_set_tlb_flushall_shift(c);
 }
 
 static const struct cpu_dev __cpuinitconst amd_cpu_dev = {
-- 
1.7.11.rc1

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