[PATCH v12 04/16] x86/mm: get INVLPGB count max from CPUID

[Rik van Riel]

The CPU advertises the maximum number of pages that can be shot down
with one INVLPGB instruction in the CPUID data.

Save that information for later use.

Signed-off-by: Rik van Riel <riel@xxxxxxxxxxx>
Tested-by: Manali Shukla <Manali.Shukla@xxxxxxx>
Tested-by: Brendan Jackman <jackmanb@xxxxxxxxxx>
Tested-by: Michael Kelley <mhklinux@xxxxxxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxx>
---
 arch/x86/Kconfig.cpu               | 5 +++++
 arch/x86/include/asm/cpufeatures.h | 1 +
 arch/x86/include/asm/tlbflush.h    | 3 +++
 arch/x86/kernel/cpu/common.c       | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 2a7279d80460..bb6943c21b7f 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -401,6 +401,10 @@ menuconfig PROCESSOR_SELECT
 	  This lets you choose what x86 vendor support code your kernel
 	  will include.
 
+config X86_BROADCAST_TLB_FLUSH
+	def_bool y
+	depends on CPU_SUP_AMD && 64BIT
+
 config CPU_SUP_INTEL
 	default y
 	bool "Support Intel processors" if PROCESSOR_SELECT
@@ -431,6 +435,7 @@ config CPU_SUP_CYRIX_32
 config CPU_SUP_AMD
 	default y
 	bool "Support AMD processors" if PROCESSOR_SELECT
+	select X86_BROADCAST_TLB_FLUSH
 	help
 	  This enables detection, tunings and quirks for AMD processors
 
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 508c0dad116b..b5c66b7465ba 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -338,6 +338,7 @@
 #define X86_FEATURE_CLZERO		(13*32+ 0) /* "clzero" CLZERO instruction */
 #define X86_FEATURE_IRPERF		(13*32+ 1) /* "irperf" Instructions Retired Count */
 #define X86_FEATURE_XSAVEERPTR		(13*32+ 2) /* "xsaveerptr" Always save/restore FP error pointers */
+#define X86_FEATURE_INVLPGB		(13*32+ 3) /* INVLPGB and TLBSYNC instruction supported. */
 #define X86_FEATURE_RDPRU		(13*32+ 4) /* "rdpru" Read processor register at user level */
 #define X86_FEATURE_WBNOINVD		(13*32+ 9) /* "wbnoinvd" WBNOINVD instruction */
 #define X86_FEATURE_AMD_IBPB		(13*32+12) /* Indirect Branch Prediction Barrier */
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 3da645139748..09463a2fb05f 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -183,6 +183,9 @@ static inline void cr4_init_shadow(void)
 extern unsigned long mmu_cr4_features;
 extern u32 *trampoline_cr4_features;
 
+/* How many pages can we invalidate with one INVLPGB. */
+extern u16 invlpgb_count_max;
+
 extern void initialize_tlbstate_and_flush(void);
 
 /*
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 7cce91b19fb2..742bdb0c4846 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -95,6 +95,8 @@ EXPORT_SYMBOL(__num_cores_per_package);
 unsigned int __num_threads_per_package __ro_after_init = 1;
 EXPORT_SYMBOL(__num_threads_per_package);
 
+u16 invlpgb_count_max __ro_after_init;
+
 static struct ppin_info {
 	int	feature;
 	int	msr_ppin_ctl;
@@ -1030,6 +1032,7 @@ void get_cpu_cap(struct cpuinfo_x86 *c)
 	if (c->extended_cpuid_level >= 0x80000008) {
 		cpuid(0x80000008, &eax, &ebx, &ecx, &edx);
 		c->x86_capability[CPUID_8000_0008_EBX] = ebx;
+		invlpgb_count_max = (edx & 0xffff) + 1;
 	}
 
 	if (c->extended_cpuid_level >= 0x8000000a)
-- 
2.47.1