[PATCH 0/3] x86, CPU: Some more cleanups and rearrangements

[PATCH 0/3] x86, CPU: Some more cleanups and rearrangements

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Hi,

some more stuff from recently:

01 adds "bugs : " line to /proc/cpuinfo to show for which hw bugs of the
current CPU the kernel knows and possibly applies a workaround.

02 is a bit big but it is basically reorganizing code around and doing
small changes like replacing cpu_has_mp with the dynamic cpu_has call so
that we can remove the former.

03 does that.

Tested on a bunch of AMD and Intel machines.

Borislav Petkov (3):
  x86, CPU: Add bug flags to /proc/cpuinfo
  x86, AMD: Cleanup init_amd
  x86, CPU: Kill cpu_has_mp

 arch/x86/include/asm/cpufeature.h |  14 +-
 arch/x86/kernel/cpu/amd.c         | 339 ++++++++++++++++++--------------------
 arch/x86/kernel/cpu/mkcapflags.sh |  51 ++++--
 arch/x86/kernel/cpu/proc.c        |   8 +
 4 files changed, 214 insertions(+), 198 deletions(-)

-- 
2.0.0

[PATCH 1/3] x86, CPU: Add bug flags to /proc/cpuinfo

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Dump the flags which denote we have detected and/or have applied bug
workarounds to the CPU we're executing on, in a similar manner to the
feature flags.

The advantage is that those are not accumulating over time like the CPU
features.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/cpufeature.h | 10 ++++++--
 arch/x86/kernel/cpu/mkcapflags.sh | 51 ++++++++++++++++++++++++++++-----------
 arch/x86/kernel/cpu/proc.c        |  8 ++++++
 3 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 52df22bde0dd..327a061f32df 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -239,8 +239,8 @@
 #define X86_BUG_F00F		X86_BUG(0) /* Intel F00F */
 #define X86_BUG_FDIV		X86_BUG(1) /* FPU FDIV */
 #define X86_BUG_COMA		X86_BUG(2) /* Cyrix 6x86 coma */
-#define X86_BUG_AMD_TLB_MMATCH	X86_BUG(3) /* AMD Erratum 383 */
-#define X86_BUG_AMD_APIC_C1E	X86_BUG(4) /* AMD Erratum 400 */
+#define X86_BUG_AMD_TLB_MMATCH	X86_BUG(3) /* "tlb_mmatch" AMD Erratum 383 */
+#define X86_BUG_AMD_APIC_C1E	X86_BUG(4) /* "apic_c1e" AMD Erratum 400 */
 #define X86_BUG_11AP		X86_BUG(5) /* Bad local APIC aka 11AP */
 #define X86_BUG_FXSAVE_LEAK	X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */
 #define X86_BUG_CLFLUSH_MONITOR	X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
@@ -253,6 +253,12 @@
 extern const char * const x86_cap_flags[NCAPINTS*32];
 extern const char * const x86_power_flags[32];
 
+/*
+ * In order to save room, we index into this array by doing
+ * X86_BUG_<name> - NCAPINTS*32.
+ */
+extern const char * const x86_bug_flags[NBUGINTS*32];
+
 #define test_cpu_cap(c, bit)						\
 	 test_bit(bit, (unsigned long *)((c)->x86_capability))
 
diff --git a/arch/x86/kernel/cpu/mkcapflags.sh b/arch/x86/kernel/cpu/mkcapflags.sh
index 2bf616505499..e2b22df964cd 100644
--- a/arch/x86/kernel/cpu/mkcapflags.sh
+++ b/arch/x86/kernel/cpu/mkcapflags.sh
@@ -1,23 +1,25 @@
 #!/bin/sh
 #
-# Generate the x86_cap_flags[] array from include/asm/cpufeature.h
+# Generate the x86_cap/bug_flags[] arrays from include/asm/cpufeature.h
 #
 
 IN=$1
 OUT=$2
 
-TABS="$(printf '\t\t\t\t\t')"
-trap 'rm "$OUT"' EXIT
+function dump_array()
+{
+	ARRAY=$1
+	SIZE=$2
+	PFX=$3
+	POSTFIX=$4
 
-(
-	echo "#ifndef _ASM_X86_CPUFEATURE_H"
-	echo "#include <asm/cpufeature.h>"
-	echo "#endif"
-	echo ""
-	echo "const char * const x86_cap_flags[NCAPINTS*32] = {"
+	PFX_SZ=$(echo $PFX | wc -c)
+	TABS="$(printf '\t\t\t\t\t')"
+
+	echo "const char * const $ARRAY[$SIZE] = {"
 
-	# Iterate through any input lines starting with #define X86_FEATURE_
-	sed -n -e 's/\t/ /g' -e 's/^ *# *define *X86_FEATURE_//p' $IN |
+	# Iterate through any input lines starting with #define $PFX
+	sed -n -e 's/\t/ /g' -e "s/^ *# *define *$PFX//p" $IN |
 	while read i
 	do
 		# Name is everything up to the first whitespace
@@ -31,11 +33,32 @@ trap 'rm "$OUT"' EXIT
 		# Name is uppercase, VALUE is all lowercase
 		VALUE="$(echo "$VALUE" | tr A-Z a-z)"
 
-		TABCOUNT=$(( ( 5*8 - 14 - $(echo "$NAME" | wc -c) ) / 8 ))
-		printf "\t[%s]%.*s = %s,\n" \
-			"X86_FEATURE_$NAME" "$TABCOUNT" "$TABS" "$VALUE"
+        if [ -n "$POSTFIX" ]; then
+            T=$(( $PFX_SZ + $(echo $POSTFIX | wc -c) + 2 ))
+	        TABS="$(printf '\t\t\t\t\t\t')"
+		    TABCOUNT=$(( ( 6*8 - ($T + 1) - $(echo "$NAME" | wc -c) ) / 8 ))
+		    printf "\t[%s - %s]%.*s = %s,\n" "$PFX$NAME" "$POSTFIX" "$TABCOUNT" "$TABS" "$VALUE"
+        else
+		    TABCOUNT=$(( ( 5*8 - ($PFX_SZ + 1) - $(echo "$NAME" | wc -c) ) / 8 ))
+            printf "\t[%s]%.*s = %s,\n" "$PFX$NAME" "$TABCOUNT" "$TABS" "$VALUE"
+        fi
 	done
 	echo "};"
+}
+
+trap 'rm "$OUT"' EXIT
+
+(
+	echo "#ifndef _ASM_X86_CPUFEATURE_H"
+	echo "#include <asm/cpufeature.h>"
+	echo "#endif"
+	echo ""
+
+	dump_array "x86_cap_flags" "NCAPINTS*32" "X86_FEATURE_" ""
+	echo ""
+
+	dump_array "x86_bug_flags" "NBUGINTS*32" "X86_BUG_" "NCAPINTS*32"
+
 ) > $OUT
 
 trap - EXIT
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 06fe3ed8b851..5433658e598d 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -97,6 +97,14 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
 			seq_printf(m, " %s", x86_cap_flags[i]);
 
+	seq_printf(m, "\nbugs\t\t:");
+	for (i = 0; i < 32*NBUGINTS; i++) {
+		unsigned int bug_bit = 32*NCAPINTS + i;
+
+		if (cpu_has_bug(c, bug_bit) && x86_bug_flags[i])
+			seq_printf(m, " %s", x86_bug_flags[i]);
+	}
+
 	seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
 		   c->loops_per_jiffy/(500000/HZ),
 		   (c->loops_per_jiffy/(5000/HZ)) % 100);
-- 
2.0.0

[PATCH 2/3] x86, AMD: Cleanup init_amd

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

Distribute family-specific code to corresponding functions.

Also,

* move the direct mapping splitting around the TSEG SMM area to
bsp_init_amd().

* kill ancient comment about what we should do for K5.

* merge amd_k7_smp_check() into its only caller init_amd_k7 and drop
cpu_has_mp macro.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/kernel/cpu/amd.c | 339 ++++++++++++++++++++++------------------------
 1 file changed, 161 insertions(+), 178 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 8714a78414bf..bc360d3df60e 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -8,6 +8,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/smp.h>
 #include <asm/pci-direct.h>
 
 #ifdef CONFIG_X86_64
@@ -50,7 +51,6 @@ static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
 	return wrmsr_safe_regs(gprs);
 }
 
-#ifdef CONFIG_X86_32
 /*
  *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause
  *	misexecution of code under Linux. Owners of such processors should
@@ -70,6 +70,7 @@ __asm__(".globl vide\n\t.align 4\nvide: ret");
 
 static void init_amd_k5(struct cpuinfo_x86 *c)
 {
+#ifdef CONFIG_X86_32
 /*
  * General Systems BIOSen alias the cpu frequency registers
  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
@@ -83,11 +84,12 @@ static void init_amd_k5(struct cpuinfo_x86 *c)
 		if (inl(CBAR) & CBAR_ENB)
 			outl(0 | CBAR_KEY, CBAR);
 	}
+#endif
 }
 
-
 static void init_amd_k6(struct cpuinfo_x86 *c)
 {
+#ifdef CONFIG_X86_32
 	u32 l, h;
 	int mbytes = get_num_physpages() >> (20-PAGE_SHIFT);
 
@@ -176,10 +178,44 @@ static void init_amd_k6(struct cpuinfo_x86 *c)
 		/* placeholder for any needed mods */
 		return;
 	}
+#endif
 }
 
-static void amd_k7_smp_check(struct cpuinfo_x86 *c)
+static void init_amd_k7(struct cpuinfo_x86 *c)
 {
+#ifdef CONFIG_X86_32
+	u32 l, h;
+
+	/*
+	 * Bit 15 of Athlon specific MSR 15, needs to be 0
+	 * to enable SSE on Palomino/Morgan/Barton CPU's.
+	 * If the BIOS didn't enable it already, enable it here.
+	 */
+	if (c->x86_model >= 6 && c->x86_model <= 10) {
+		if (!cpu_has(c, X86_FEATURE_XMM)) {
+			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
+			msr_clear_bit(MSR_K7_HWCR, 15);
+			set_cpu_cap(c, X86_FEATURE_XMM);
+		}
+	}
+
+	/*
+	 * It's been determined by AMD that Athlons since model 8 stepping 1
+	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
+	 * As per AMD technical note 27212 0.2
+	 */
+	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
+		rdmsr(MSR_K7_CLK_CTL, l, h);
+		if ((l & 0xfff00000) != 0x20000000) {
+			printk(KERN_INFO
+			    "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
+					l, ((l & 0x000fffff)|0x20000000));
+			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
+		}
+	}
+
+	set_cpu_cap(c, X86_FEATURE_K7);
+
 	/* calling is from identify_secondary_cpu() ? */
 	if (!c->cpu_index)
 		return;
@@ -207,7 +243,7 @@ static void amd_k7_smp_check(struct cpuinfo_x86 *c)
 	if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
 	    ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
 	     (c->x86_model > 7))
-		if (cpu_has_mp)
+		if (cpu_has(c, X86_FEATURE_MP))
 			return;
 
 	/* If we get here, not a certified SMP capable AMD system. */
@@ -219,45 +255,8 @@ static void amd_k7_smp_check(struct cpuinfo_x86 *c)
 	WARN_ONCE(1, "WARNING: This combination of AMD"
 		" processors is not suitable for SMP.\n");
 	add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
-}
-
-static void init_amd_k7(struct cpuinfo_x86 *c)
-{
-	u32 l, h;
-
-	/*
-	 * Bit 15 of Athlon specific MSR 15, needs to be 0
-	 * to enable SSE on Palomino/Morgan/Barton CPU's.
-	 * If the BIOS didn't enable it already, enable it here.
-	 */
-	if (c->x86_model >= 6 && c->x86_model <= 10) {
-		if (!cpu_has(c, X86_FEATURE_XMM)) {
-			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
-			msr_clear_bit(MSR_K7_HWCR, 15);
-			set_cpu_cap(c, X86_FEATURE_XMM);
-		}
-	}
-
-	/*
-	 * It's been determined by AMD that Athlons since model 8 stepping 1
-	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
-	 * As per AMD technical note 27212 0.2
-	 */
-	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
-		rdmsr(MSR_K7_CLK_CTL, l, h);
-		if ((l & 0xfff00000) != 0x20000000) {
-			printk(KERN_INFO
-			    "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
-					l, ((l & 0x000fffff)|0x20000000));
-			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
-		}
-	}
-
-	set_cpu_cap(c, X86_FEATURE_K7);
-
-	amd_k7_smp_check(c);
-}
 #endif
+}
 
 #ifdef CONFIG_NUMA
 /*
@@ -446,6 +445,26 @@ static void early_init_amd_mc(struct cpuinfo_x86 *c)
 
 static void bsp_init_amd(struct cpuinfo_x86 *c)
 {
+
+#ifdef CONFIG_X86_64
+	if (c->x86 >= 0xf) {
+		unsigned long long tseg;
+
+		/*
+		 * Split up direct mapping around the TSEG SMM area.
+		 * Don't do it for gbpages because there seems very little
+		 * benefit in doing so.
+		 */
+		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
+			unsigned long pfn = tseg >> PAGE_SHIFT;
+
+			printk(KERN_DEBUG "tseg: %010llx\n", tseg);
+			if (pfn_range_is_mapped(pfn, pfn + 1))
+				set_memory_4k((unsigned long)__va(tseg), 1);
+		}
+	}
+#endif
+
 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
 
 		if (c->x86 > 0x10 ||
@@ -515,10 +534,100 @@ static const int amd_erratum_383[];
 static const int amd_erratum_400[];
 static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum);
 
+static void init_amd_k8(struct cpuinfo_x86 *c)
+{
+	u32 level;
+	u64 value;
+
+	/* On C+ stepping K8 rep microcode works well for copy/memset */
+	level = cpuid_eax(1);
+	if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
+		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
+
+	/*
+	 * Some BIOSes incorrectly force this feature, but only K8 revision D
+	 * (model = 0x14) and later actually support it.
+	 * (AMD Erratum #110, docId: 25759).
+	 */
+	if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
+		clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
+		if (!rdmsrl_amd_safe(0xc001100d, &value)) {
+			value &= ~BIT_64(32);
+			wrmsrl_amd_safe(0xc001100d, value);
+		}
+	}
+
+	if (!c->x86_model_id[0])
+		strcpy(c->x86_model_id, "Hammer");
+}
+
+static void init_amd_gh(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_X86_64
+	/* do this for boot cpu */
+	if (c == &boot_cpu_data)
+		check_enable_amd_mmconf_dmi();
+
+	fam10h_check_enable_mmcfg();
+#endif
+
+	/*
+	 * Disable GART TLB Walk Errors on Fam10h. We do this here because this
+	 * is always needed when GART is enabled, even in a kernel which has no
+	 * MCE support built in. BIOS should disable GartTlbWlk Errors already.
+	 * If it doesn't, we do it here as suggested by the BKDG.
+	 *
+	 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
+	 */
+	msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);
+
+	/*
+	 * On family 10h BIOS may not have properly enabled WC+ support, causing
+	 * it to be converted to CD memtype. This may result in performance
+	 * degradation for certain nested-paging guests. Prevent this conversion
+	 * by clearing bit 24 in MSR_AMD64_BU_CFG2.
+	 *
+	 * NOTE: we want to use the _safe accessors so as not to #GP kvm
+	 * guests on older kvm hosts.
+	 */
+	msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
+
+	if (cpu_has_amd_erratum(c, amd_erratum_383))
+		set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
+}
+
+static void init_amd_bd(struct cpuinfo_x86 *c)
+{
+	u64 value;
+
+	/* re-enable TopologyExtensions if switched off by BIOS */
+	if ((c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
+	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {
+
+		if (msr_set_bit(0xc0011005, 54) > 0) {
+			rdmsrl(0xc0011005, value);
+			if (value & BIT_64(54)) {
+				set_cpu_cap(c, X86_FEATURE_TOPOEXT);
+				pr_info(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
+			}
+		}
+	}
+
+	/*
+	 * The way access filter has a performance penalty on some workloads.
+	 * Disable it on the affected CPUs.
+	 */
+	if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
+		if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
+			value |= 0x1E;
+			wrmsrl_safe(0xc0011021, value);
+		}
+	}
+}
+
 static void init_amd(struct cpuinfo_x86 *c)
 {
 	u32 dummy;
-	unsigned long long value;
 
 #ifdef CONFIG_SMP
 	/*
@@ -540,100 +649,29 @@ static void init_amd(struct cpuinfo_x86 *c)
 	 */
 	clear_cpu_cap(c, 0*32+31);
 
-#ifdef CONFIG_X86_64
-	/* On C+ stepping K8 rep microcode works well for copy/memset */
-	if (c->x86 == 0xf) {
-		u32 level;
-
-		level = cpuid_eax(1);
-		if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
-			set_cpu_cap(c, X86_FEATURE_REP_GOOD);
-
-		/*
-		 * Some BIOSes incorrectly force this feature, but only K8
-		 * revision D (model = 0x14) and later actually support it.
-		 * (AMD Erratum #110, docId: 25759).
-		 */
-		if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
-			clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
-			if (!rdmsrl_amd_safe(0xc001100d, &value)) {
-				value &= ~(1ULL << 32);
-				wrmsrl_amd_safe(0xc001100d, value);
-			}
-		}
-
-	}
 	if (c->x86 >= 0x10)
 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 
 	/* get apicid instead of initial apic id from cpuid */
 	c->apicid = hard_smp_processor_id();
-#else
-
-	/*
-	 *	FIXME: We should handle the K5 here. Set up the write
-	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,
-	 *	no bus pipeline)
-	 */
-
-	switch (c->x86) {
-	case 4:
-		init_amd_k5(c);
-		break;
-	case 5:
-		init_amd_k6(c);
-		break;
-	case 6: /* An Athlon/Duron */
-		init_amd_k7(c);
-		break;
-	}
 
 	/* K6s reports MCEs but don't actually have all the MSRs */
 	if (c->x86 < 6)
 		clear_cpu_cap(c, X86_FEATURE_MCE);
-#endif
+
+	switch (c->x86) {
+	case 4:    init_amd_k5(c); break;
+	case 5:    init_amd_k6(c); break;
+	case 6:	   init_amd_k7(c); break;
+	case 0xf:  init_amd_k8(c); break;
+	case 0x10: init_amd_gh(c); break;
+	case 0x15: init_amd_bd(c); break;
+	}
 
 	/* Enable workaround for FXSAVE leak */
 	if (c->x86 >= 6)
 		set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);
 
-	if (!c->x86_model_id[0]) {
-		switch (c->x86) {
-		case 0xf:
-			/* Should distinguish Models here, but this is only
-			   a fallback anyways. */
-			strcpy(c->x86_model_id, "Hammer");
-			break;
-		}
-	}
-
-	/* re-enable TopologyExtensions if switched off by BIOS */
-	if ((c->x86 == 0x15) &&
-	    (c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
-	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {
-
-		if (msr_set_bit(0xc0011005, 54) > 0) {
-			rdmsrl(0xc0011005, value);
-			if (value & BIT_64(54)) {
-				set_cpu_cap(c, X86_FEATURE_TOPOEXT);
-				pr_info(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
-			}
-		}
-	}
-
-	/*
-	 * The way access filter has a performance penalty on some workloads.
-	 * Disable it on the affected CPUs.
-	 */
-	if ((c->x86 == 0x15) &&
-	    (c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
-
-		if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
-			value |= 0x1E;
-			wrmsrl_safe(0xc0011021, value);
-		}
-	}
-
 	cpu_detect_cache_sizes(c);
 
 	/* Multi core CPU? */
@@ -656,33 +694,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
 	}
 
-#ifdef CONFIG_X86_64
-	if (c->x86 == 0x10) {
-		/* do this for boot cpu */
-		if (c == &boot_cpu_data)
-			check_enable_amd_mmconf_dmi();
-
-		fam10h_check_enable_mmcfg();
-	}
-
-	if (c == &boot_cpu_data && c->x86 >= 0xf) {
-		unsigned long long tseg;
-
-		/*
-		 * Split up direct mapping around the TSEG SMM area.
-		 * Don't do it for gbpages because there seems very little
-		 * benefit in doing so.
-		 */
-		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
-			unsigned long pfn = tseg >> PAGE_SHIFT;
-
-			printk(KERN_DEBUG "tseg: %010llx\n", tseg);
-			if (pfn_range_is_mapped(pfn, pfn + 1))
-				set_memory_4k((unsigned long)__va(tseg), 1);
-		}
-	}
-#endif
-
 	/*
 	 * Family 0x12 and above processors have APIC timer
 	 * running in deep C states.
@@ -690,34 +701,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 	if (c->x86 > 0x11)
 		set_cpu_cap(c, X86_FEATURE_ARAT);
 
-	if (c->x86 == 0x10) {
-		/*
-		 * Disable GART TLB Walk Errors on Fam10h. We do this here
-		 * because this is always needed when GART is enabled, even in a
-		 * kernel which has no MCE support built in.
-		 * BIOS should disable GartTlbWlk Errors already. If
-		 * it doesn't, do it here as suggested by the BKDG.
-		 *
-		 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
-		 */
-		msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);
-
-		/*
-		 * On family 10h BIOS may not have properly enabled WC+ support,
-		 * causing it to be converted to CD memtype. This may result in
-		 * performance degradation for certain nested-paging guests.
-		 * Prevent this conversion by clearing bit 24 in
-		 * MSR_AMD64_BU_CFG2.
-		 *
-		 * NOTE: we want to use the _safe accessors so as not to #GP kvm
-		 * guests on older kvm hosts.
-		 */
-		msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
-
-		if (cpu_has_amd_erratum(c, amd_erratum_383))
-			set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
-	}
-
 	if (cpu_has_amd_erratum(c, amd_erratum_400))
 		set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);
 
-- 
2.0.0

[PATCH 3/3] x86, CPU: Kill cpu_has_mp

[Borislav Petkov]

From: Borislav Petkov <bp@suse.de>

It was used only for checking for some K7s which didn't have MP support,
see

http://www.hardwaresecrets.com/article/How-to-Transform-an-Athlon-XP-into-an-Athlon-MP/24

and it was unconditionally set on 64-bit for no reason. Kill it.

Signed-off-by: Borislav Petkov <bp@suse.de>
---
 arch/x86/include/asm/cpufeature.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 327a061f32df..bb9b258d60e7 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -315,7 +315,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 #define cpu_has_avx		boot_cpu_has(X86_FEATURE_AVX)
 #define cpu_has_avx2		boot_cpu_has(X86_FEATURE_AVX2)
 #define cpu_has_ht		boot_cpu_has(X86_FEATURE_HT)
-#define cpu_has_mp		boot_cpu_has(X86_FEATURE_MP)
 #define cpu_has_nx		boot_cpu_has(X86_FEATURE_NX)
 #define cpu_has_k6_mtrr		boot_cpu_has(X86_FEATURE_K6_MTRR)
 #define cpu_has_cyrix_arr	boot_cpu_has(X86_FEATURE_CYRIX_ARR)
@@ -362,9 +361,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 #undef  cpu_has_pae
 #define cpu_has_pae		___BUG___
 
-#undef  cpu_has_mp
-#define cpu_has_mp		1
-
 #undef  cpu_has_k6_mtrr
 #define cpu_has_k6_mtrr		0
 
-- 
2.0.0

[tip:x86/cpufeature] x86/cpufeature: Add bug flags to /proc/ cpuinfo

[tip-bot for Borislav Petkov]

Commit-ID:  80a208bd3948aceddf0429bd9f9b4cd858d526df
Gitweb:     http://git.kernel.org/tip/80a208bd3948aceddf0429bd9f9b4cd858d526df
Author:     Borislav Petkov <bp@suse.de>
AuthorDate: Tue, 24 Jun 2014 13:25:03 +0200
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 14 Jul 2014 12:21:39 -0700

x86/cpufeature: Add bug flags to /proc/cpuinfo

Dump the flags which denote we have detected and/or have applied bug
workarounds to the CPU we're executing on, in a similar manner to the
feature flags.

The advantage is that those are not accumulating over time like the CPU
features.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1403609105-8332-2-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/include/asm/cpufeature.h | 10 ++++++--
 arch/x86/kernel/cpu/mkcapflags.sh | 51 ++++++++++++++++++++++++++++-----------
 arch/x86/kernel/cpu/proc.c        |  8 ++++++
 3 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 52df22b..327a061 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -239,8 +239,8 @@
 #define X86_BUG_F00F		X86_BUG(0) /* Intel F00F */
 #define X86_BUG_FDIV		X86_BUG(1) /* FPU FDIV */
 #define X86_BUG_COMA		X86_BUG(2) /* Cyrix 6x86 coma */
-#define X86_BUG_AMD_TLB_MMATCH	X86_BUG(3) /* AMD Erratum 383 */
-#define X86_BUG_AMD_APIC_C1E	X86_BUG(4) /* AMD Erratum 400 */
+#define X86_BUG_AMD_TLB_MMATCH	X86_BUG(3) /* "tlb_mmatch" AMD Erratum 383 */
+#define X86_BUG_AMD_APIC_C1E	X86_BUG(4) /* "apic_c1e" AMD Erratum 400 */
 #define X86_BUG_11AP		X86_BUG(5) /* Bad local APIC aka 11AP */
 #define X86_BUG_FXSAVE_LEAK	X86_BUG(6) /* FXSAVE leaks FOP/FIP/FOP */
 #define X86_BUG_CLFLUSH_MONITOR	X86_BUG(7) /* AAI65, CLFLUSH required before MONITOR */
@@ -253,6 +253,12 @@
 extern const char * const x86_cap_flags[NCAPINTS*32];
 extern const char * const x86_power_flags[32];
 
+/*
+ * In order to save room, we index into this array by doing
+ * X86_BUG_<name> - NCAPINTS*32.
+ */
+extern const char * const x86_bug_flags[NBUGINTS*32];
+
 #define test_cpu_cap(c, bit)						\
 	 test_bit(bit, (unsigned long *)((c)->x86_capability))
 
diff --git a/arch/x86/kernel/cpu/mkcapflags.sh b/arch/x86/kernel/cpu/mkcapflags.sh
index 2bf6165..e2b22df 100644
--- a/arch/x86/kernel/cpu/mkcapflags.sh
+++ b/arch/x86/kernel/cpu/mkcapflags.sh
@@ -1,23 +1,25 @@
 #!/bin/sh
 #
-# Generate the x86_cap_flags[] array from include/asm/cpufeature.h
+# Generate the x86_cap/bug_flags[] arrays from include/asm/cpufeature.h
 #
 
 IN=$1
 OUT=$2
 
-TABS="$(printf '\t\t\t\t\t')"
-trap 'rm "$OUT"' EXIT
+function dump_array()
+{
+	ARRAY=$1
+	SIZE=$2
+	PFX=$3
+	POSTFIX=$4
 
-(
-	echo "#ifndef _ASM_X86_CPUFEATURE_H"
-	echo "#include <asm/cpufeature.h>"
-	echo "#endif"
-	echo ""
-	echo "const char * const x86_cap_flags[NCAPINTS*32] = {"
+	PFX_SZ=$(echo $PFX | wc -c)
+	TABS="$(printf '\t\t\t\t\t')"
+
+	echo "const char * const $ARRAY[$SIZE] = {"
 
-	# Iterate through any input lines starting with #define X86_FEATURE_
-	sed -n -e 's/\t/ /g' -e 's/^ *# *define *X86_FEATURE_//p' $IN |
+	# Iterate through any input lines starting with #define $PFX
+	sed -n -e 's/\t/ /g' -e "s/^ *# *define *$PFX//p" $IN |
 	while read i
 	do
 		# Name is everything up to the first whitespace
@@ -31,11 +33,32 @@ trap 'rm "$OUT"' EXIT
 		# Name is uppercase, VALUE is all lowercase
 		VALUE="$(echo "$VALUE" | tr A-Z a-z)"
 
-		TABCOUNT=$(( ( 5*8 - 14 - $(echo "$NAME" | wc -c) ) / 8 ))
-		printf "\t[%s]%.*s = %s,\n" \
-			"X86_FEATURE_$NAME" "$TABCOUNT" "$TABS" "$VALUE"
+        if [ -n "$POSTFIX" ]; then
+            T=$(( $PFX_SZ + $(echo $POSTFIX | wc -c) + 2 ))
+	        TABS="$(printf '\t\t\t\t\t\t')"
+		    TABCOUNT=$(( ( 6*8 - ($T + 1) - $(echo "$NAME" | wc -c) ) / 8 ))
+		    printf "\t[%s - %s]%.*s = %s,\n" "$PFX$NAME" "$POSTFIX" "$TABCOUNT" "$TABS" "$VALUE"
+        else
+		    TABCOUNT=$(( ( 5*8 - ($PFX_SZ + 1) - $(echo "$NAME" | wc -c) ) / 8 ))
+            printf "\t[%s]%.*s = %s,\n" "$PFX$NAME" "$TABCOUNT" "$TABS" "$VALUE"
+        fi
 	done
 	echo "};"
+}
+
+trap 'rm "$OUT"' EXIT
+
+(
+	echo "#ifndef _ASM_X86_CPUFEATURE_H"
+	echo "#include <asm/cpufeature.h>"
+	echo "#endif"
+	echo ""
+
+	dump_array "x86_cap_flags" "NCAPINTS*32" "X86_FEATURE_" ""
+	echo ""
+
+	dump_array "x86_bug_flags" "NBUGINTS*32" "X86_BUG_" "NCAPINTS*32"
+
 ) > $OUT
 
 trap - EXIT
diff --git a/arch/x86/kernel/cpu/proc.c b/arch/x86/kernel/cpu/proc.c
index 06fe3ed..5433658 100644
--- a/arch/x86/kernel/cpu/proc.c
+++ b/arch/x86/kernel/cpu/proc.c
@@ -97,6 +97,14 @@ static int show_cpuinfo(struct seq_file *m, void *v)
 		if (cpu_has(c, i) && x86_cap_flags[i] != NULL)
 			seq_printf(m, " %s", x86_cap_flags[i]);
 
+	seq_printf(m, "\nbugs\t\t:");
+	for (i = 0; i < 32*NBUGINTS; i++) {
+		unsigned int bug_bit = 32*NCAPINTS + i;
+
+		if (cpu_has_bug(c, bug_bit) && x86_bug_flags[i])
+			seq_printf(m, " %s", x86_bug_flags[i]);
+	}
+
 	seq_printf(m, "\nbogomips\t: %lu.%02lu\n",
 		   c->loops_per_jiffy/(500000/HZ),
 		   (c->loops_per_jiffy/(5000/HZ)) % 100);

[tip:x86/cpufeature] x86, amd: Cleanup init_amd

[tip-bot for Borislav Petkov]

Commit-ID:  26bfa5f89486a8926cd4d4ca81a04d3f0f174934
Gitweb:     http://git.kernel.org/tip/26bfa5f89486a8926cd4d4ca81a04d3f0f174934
Author:     Borislav Petkov <bp@suse.de>
AuthorDate: Tue, 24 Jun 2014 13:25:04 +0200
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 14 Jul 2014 12:21:40 -0700

x86, amd: Cleanup init_amd

Distribute family-specific code to corresponding functions.

Also,

* move the direct mapping splitting around the TSEG SMM area to
bsp_init_amd().

* kill ancient comment about what we should do for K5.

* merge amd_k7_smp_check() into its only caller init_amd_k7 and drop
cpu_has_mp macro.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1403609105-8332-3-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/kernel/cpu/amd.c | 339 ++++++++++++++++++++++------------------------
 1 file changed, 161 insertions(+), 178 deletions(-)

diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index 8714a78..bc360d3 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -8,6 +8,7 @@
 #include <asm/processor.h>
 #include <asm/apic.h>
 #include <asm/cpu.h>
+#include <asm/smp.h>
 #include <asm/pci-direct.h>
 
 #ifdef CONFIG_X86_64
@@ -50,7 +51,6 @@ static inline int wrmsrl_amd_safe(unsigned msr, unsigned long long val)
 	return wrmsr_safe_regs(gprs);
 }
 
-#ifdef CONFIG_X86_32
 /*
  *	B step AMD K6 before B 9730xxxx have hardware bugs that can cause
  *	misexecution of code under Linux. Owners of such processors should
@@ -70,6 +70,7 @@ __asm__(".globl vide\n\t.align 4\nvide: ret");
 
 static void init_amd_k5(struct cpuinfo_x86 *c)
 {
+#ifdef CONFIG_X86_32
 /*
  * General Systems BIOSen alias the cpu frequency registers
  * of the Elan at 0x000df000. Unfortuantly, one of the Linux
@@ -83,11 +84,12 @@ static void init_amd_k5(struct cpuinfo_x86 *c)
 		if (inl(CBAR) & CBAR_ENB)
 			outl(0 | CBAR_KEY, CBAR);
 	}
+#endif
 }
 
-
 static void init_amd_k6(struct cpuinfo_x86 *c)
 {
+#ifdef CONFIG_X86_32
 	u32 l, h;
 	int mbytes = get_num_physpages() >> (20-PAGE_SHIFT);
 
@@ -176,10 +178,44 @@ static void init_amd_k6(struct cpuinfo_x86 *c)
 		/* placeholder for any needed mods */
 		return;
 	}
+#endif
 }
 
-static void amd_k7_smp_check(struct cpuinfo_x86 *c)
+static void init_amd_k7(struct cpuinfo_x86 *c)
 {
+#ifdef CONFIG_X86_32
+	u32 l, h;
+
+	/*
+	 * Bit 15 of Athlon specific MSR 15, needs to be 0
+	 * to enable SSE on Palomino/Morgan/Barton CPU's.
+	 * If the BIOS didn't enable it already, enable it here.
+	 */
+	if (c->x86_model >= 6 && c->x86_model <= 10) {
+		if (!cpu_has(c, X86_FEATURE_XMM)) {
+			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
+			msr_clear_bit(MSR_K7_HWCR, 15);
+			set_cpu_cap(c, X86_FEATURE_XMM);
+		}
+	}
+
+	/*
+	 * It's been determined by AMD that Athlons since model 8 stepping 1
+	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
+	 * As per AMD technical note 27212 0.2
+	 */
+	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
+		rdmsr(MSR_K7_CLK_CTL, l, h);
+		if ((l & 0xfff00000) != 0x20000000) {
+			printk(KERN_INFO
+			    "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
+					l, ((l & 0x000fffff)|0x20000000));
+			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
+		}
+	}
+
+	set_cpu_cap(c, X86_FEATURE_K7);
+
 	/* calling is from identify_secondary_cpu() ? */
 	if (!c->cpu_index)
 		return;
@@ -207,7 +243,7 @@ static void amd_k7_smp_check(struct cpuinfo_x86 *c)
 	if (((c->x86_model == 6) && (c->x86_mask >= 2)) ||
 	    ((c->x86_model == 7) && (c->x86_mask >= 1)) ||
 	     (c->x86_model > 7))
-		if (cpu_has_mp)
+		if (cpu_has(c, X86_FEATURE_MP))
 			return;
 
 	/* If we get here, not a certified SMP capable AMD system. */
@@ -219,45 +255,8 @@ static void amd_k7_smp_check(struct cpuinfo_x86 *c)
 	WARN_ONCE(1, "WARNING: This combination of AMD"
 		" processors is not suitable for SMP.\n");
 	add_taint(TAINT_CPU_OUT_OF_SPEC, LOCKDEP_NOW_UNRELIABLE);
-}
-
-static void init_amd_k7(struct cpuinfo_x86 *c)
-{
-	u32 l, h;
-
-	/*
-	 * Bit 15 of Athlon specific MSR 15, needs to be 0
-	 * to enable SSE on Palomino/Morgan/Barton CPU's.
-	 * If the BIOS didn't enable it already, enable it here.
-	 */
-	if (c->x86_model >= 6 && c->x86_model <= 10) {
-		if (!cpu_has(c, X86_FEATURE_XMM)) {
-			printk(KERN_INFO "Enabling disabled K7/SSE Support.\n");
-			msr_clear_bit(MSR_K7_HWCR, 15);
-			set_cpu_cap(c, X86_FEATURE_XMM);
-		}
-	}
-
-	/*
-	 * It's been determined by AMD that Athlons since model 8 stepping 1
-	 * are more robust with CLK_CTL set to 200xxxxx instead of 600xxxxx
-	 * As per AMD technical note 27212 0.2
-	 */
-	if ((c->x86_model == 8 && c->x86_mask >= 1) || (c->x86_model > 8)) {
-		rdmsr(MSR_K7_CLK_CTL, l, h);
-		if ((l & 0xfff00000) != 0x20000000) {
-			printk(KERN_INFO
-			    "CPU: CLK_CTL MSR was %x. Reprogramming to %x\n",
-					l, ((l & 0x000fffff)|0x20000000));
-			wrmsr(MSR_K7_CLK_CTL, (l & 0x000fffff)|0x20000000, h);
-		}
-	}
-
-	set_cpu_cap(c, X86_FEATURE_K7);
-
-	amd_k7_smp_check(c);
-}
 #endif
+}
 
 #ifdef CONFIG_NUMA
 /*
@@ -446,6 +445,26 @@ static void early_init_amd_mc(struct cpuinfo_x86 *c)
 
 static void bsp_init_amd(struct cpuinfo_x86 *c)
 {
+
+#ifdef CONFIG_X86_64
+	if (c->x86 >= 0xf) {
+		unsigned long long tseg;
+
+		/*
+		 * Split up direct mapping around the TSEG SMM area.
+		 * Don't do it for gbpages because there seems very little
+		 * benefit in doing so.
+		 */
+		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
+			unsigned long pfn = tseg >> PAGE_SHIFT;
+
+			printk(KERN_DEBUG "tseg: %010llx\n", tseg);
+			if (pfn_range_is_mapped(pfn, pfn + 1))
+				set_memory_4k((unsigned long)__va(tseg), 1);
+		}
+	}
+#endif
+
 	if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
 
 		if (c->x86 > 0x10 ||
@@ -515,10 +534,100 @@ static const int amd_erratum_383[];
 static const int amd_erratum_400[];
 static bool cpu_has_amd_erratum(struct cpuinfo_x86 *cpu, const int *erratum);
 
+static void init_amd_k8(struct cpuinfo_x86 *c)
+{
+	u32 level;
+	u64 value;
+
+	/* On C+ stepping K8 rep microcode works well for copy/memset */
+	level = cpuid_eax(1);
+	if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
+		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
+
+	/*
+	 * Some BIOSes incorrectly force this feature, but only K8 revision D
+	 * (model = 0x14) and later actually support it.
+	 * (AMD Erratum #110, docId: 25759).
+	 */
+	if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
+		clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
+		if (!rdmsrl_amd_safe(0xc001100d, &value)) {
+			value &= ~BIT_64(32);
+			wrmsrl_amd_safe(0xc001100d, value);
+		}
+	}
+
+	if (!c->x86_model_id[0])
+		strcpy(c->x86_model_id, "Hammer");
+}
+
+static void init_amd_gh(struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_X86_64
+	/* do this for boot cpu */
+	if (c == &boot_cpu_data)
+		check_enable_amd_mmconf_dmi();
+
+	fam10h_check_enable_mmcfg();
+#endif
+
+	/*
+	 * Disable GART TLB Walk Errors on Fam10h. We do this here because this
+	 * is always needed when GART is enabled, even in a kernel which has no
+	 * MCE support built in. BIOS should disable GartTlbWlk Errors already.
+	 * If it doesn't, we do it here as suggested by the BKDG.
+	 *
+	 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
+	 */
+	msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);
+
+	/*
+	 * On family 10h BIOS may not have properly enabled WC+ support, causing
+	 * it to be converted to CD memtype. This may result in performance
+	 * degradation for certain nested-paging guests. Prevent this conversion
+	 * by clearing bit 24 in MSR_AMD64_BU_CFG2.
+	 *
+	 * NOTE: we want to use the _safe accessors so as not to #GP kvm
+	 * guests on older kvm hosts.
+	 */
+	msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
+
+	if (cpu_has_amd_erratum(c, amd_erratum_383))
+		set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
+}
+
+static void init_amd_bd(struct cpuinfo_x86 *c)
+{
+	u64 value;
+
+	/* re-enable TopologyExtensions if switched off by BIOS */
+	if ((c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
+	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {
+
+		if (msr_set_bit(0xc0011005, 54) > 0) {
+			rdmsrl(0xc0011005, value);
+			if (value & BIT_64(54)) {
+				set_cpu_cap(c, X86_FEATURE_TOPOEXT);
+				pr_info(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
+			}
+		}
+	}
+
+	/*
+	 * The way access filter has a performance penalty on some workloads.
+	 * Disable it on the affected CPUs.
+	 */
+	if ((c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
+		if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
+			value |= 0x1E;
+			wrmsrl_safe(0xc0011021, value);
+		}
+	}
+}
+
 static void init_amd(struct cpuinfo_x86 *c)
 {
 	u32 dummy;
-	unsigned long long value;
 
 #ifdef CONFIG_SMP
 	/*
@@ -540,100 +649,29 @@ static void init_amd(struct cpuinfo_x86 *c)
 	 */
 	clear_cpu_cap(c, 0*32+31);
 
-#ifdef CONFIG_X86_64
-	/* On C+ stepping K8 rep microcode works well for copy/memset */
-	if (c->x86 == 0xf) {
-		u32 level;
-
-		level = cpuid_eax(1);
-		if ((level >= 0x0f48 && level < 0x0f50) || level >= 0x0f58)
-			set_cpu_cap(c, X86_FEATURE_REP_GOOD);
-
-		/*
-		 * Some BIOSes incorrectly force this feature, but only K8
-		 * revision D (model = 0x14) and later actually support it.
-		 * (AMD Erratum #110, docId: 25759).
-		 */
-		if (c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) {
-			clear_cpu_cap(c, X86_FEATURE_LAHF_LM);
-			if (!rdmsrl_amd_safe(0xc001100d, &value)) {
-				value &= ~(1ULL << 32);
-				wrmsrl_amd_safe(0xc001100d, value);
-			}
-		}
-
-	}
 	if (c->x86 >= 0x10)
 		set_cpu_cap(c, X86_FEATURE_REP_GOOD);
 
 	/* get apicid instead of initial apic id from cpuid */
 	c->apicid = hard_smp_processor_id();
-#else
-
-	/*
-	 *	FIXME: We should handle the K5 here. Set up the write
-	 *	range and also turn on MSR 83 bits 4 and 31 (write alloc,
-	 *	no bus pipeline)
-	 */
-
-	switch (c->x86) {
-	case 4:
-		init_amd_k5(c);
-		break;
-	case 5:
-		init_amd_k6(c);
-		break;
-	case 6: /* An Athlon/Duron */
-		init_amd_k7(c);
-		break;
-	}
 
 	/* K6s reports MCEs but don't actually have all the MSRs */
 	if (c->x86 < 6)
 		clear_cpu_cap(c, X86_FEATURE_MCE);
-#endif
+
+	switch (c->x86) {
+	case 4:    init_amd_k5(c); break;
+	case 5:    init_amd_k6(c); break;
+	case 6:	   init_amd_k7(c); break;
+	case 0xf:  init_amd_k8(c); break;
+	case 0x10: init_amd_gh(c); break;
+	case 0x15: init_amd_bd(c); break;
+	}
 
 	/* Enable workaround for FXSAVE leak */
 	if (c->x86 >= 6)
 		set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);
 
-	if (!c->x86_model_id[0]) {
-		switch (c->x86) {
-		case 0xf:
-			/* Should distinguish Models here, but this is only
-			   a fallback anyways. */
-			strcpy(c->x86_model_id, "Hammer");
-			break;
-		}
-	}
-
-	/* re-enable TopologyExtensions if switched off by BIOS */
-	if ((c->x86 == 0x15) &&
-	    (c->x86_model >= 0x10) && (c->x86_model <= 0x1f) &&
-	    !cpu_has(c, X86_FEATURE_TOPOEXT)) {
-
-		if (msr_set_bit(0xc0011005, 54) > 0) {
-			rdmsrl(0xc0011005, value);
-			if (value & BIT_64(54)) {
-				set_cpu_cap(c, X86_FEATURE_TOPOEXT);
-				pr_info(FW_INFO "CPU: Re-enabling disabled Topology Extensions Support.\n");
-			}
-		}
-	}
-
-	/*
-	 * The way access filter has a performance penalty on some workloads.
-	 * Disable it on the affected CPUs.
-	 */
-	if ((c->x86 == 0x15) &&
-	    (c->x86_model >= 0x02) && (c->x86_model < 0x20)) {
-
-		if (!rdmsrl_safe(0xc0011021, &value) && !(value & 0x1E)) {
-			value |= 0x1E;
-			wrmsrl_safe(0xc0011021, value);
-		}
-	}
-
 	cpu_detect_cache_sizes(c);
 
 	/* Multi core CPU? */
@@ -656,33 +694,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 		set_cpu_cap(c, X86_FEATURE_MFENCE_RDTSC);
 	}
 
-#ifdef CONFIG_X86_64
-	if (c->x86 == 0x10) {
-		/* do this for boot cpu */
-		if (c == &boot_cpu_data)
-			check_enable_amd_mmconf_dmi();
-
-		fam10h_check_enable_mmcfg();
-	}
-
-	if (c == &boot_cpu_data && c->x86 >= 0xf) {
-		unsigned long long tseg;
-
-		/*
-		 * Split up direct mapping around the TSEG SMM area.
-		 * Don't do it for gbpages because there seems very little
-		 * benefit in doing so.
-		 */
-		if (!rdmsrl_safe(MSR_K8_TSEG_ADDR, &tseg)) {
-			unsigned long pfn = tseg >> PAGE_SHIFT;
-
-			printk(KERN_DEBUG "tseg: %010llx\n", tseg);
-			if (pfn_range_is_mapped(pfn, pfn + 1))
-				set_memory_4k((unsigned long)__va(tseg), 1);
-		}
-	}
-#endif
-
 	/*
 	 * Family 0x12 and above processors have APIC timer
 	 * running in deep C states.
@@ -690,34 +701,6 @@ static void init_amd(struct cpuinfo_x86 *c)
 	if (c->x86 > 0x11)
 		set_cpu_cap(c, X86_FEATURE_ARAT);
 
-	if (c->x86 == 0x10) {
-		/*
-		 * Disable GART TLB Walk Errors on Fam10h. We do this here
-		 * because this is always needed when GART is enabled, even in a
-		 * kernel which has no MCE support built in.
-		 * BIOS should disable GartTlbWlk Errors already. If
-		 * it doesn't, do it here as suggested by the BKDG.
-		 *
-		 * Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=33012
-		 */
-		msr_set_bit(MSR_AMD64_MCx_MASK(4), 10);
-
-		/*
-		 * On family 10h BIOS may not have properly enabled WC+ support,
-		 * causing it to be converted to CD memtype. This may result in
-		 * performance degradation for certain nested-paging guests.
-		 * Prevent this conversion by clearing bit 24 in
-		 * MSR_AMD64_BU_CFG2.
-		 *
-		 * NOTE: we want to use the _safe accessors so as not to #GP kvm
-		 * guests on older kvm hosts.
-		 */
-		msr_clear_bit(MSR_AMD64_BU_CFG2, 24);
-
-		if (cpu_has_amd_erratum(c, amd_erratum_383))
-			set_cpu_bug(c, X86_BUG_AMD_TLB_MMATCH);
-	}
-
 	if (cpu_has_amd_erratum(c, amd_erratum_400))
 		set_cpu_bug(c, X86_BUG_AMD_APIC_C1E);
 

[tip:x86/cpufeature] x86, cpu: Kill cpu_has_mp

[tip-bot for Borislav Petkov]

Commit-ID:  af0fa6f6b5851761e9fbf79eb14ba86e857b4e7b
Gitweb:     http://git.kernel.org/tip/af0fa6f6b5851761e9fbf79eb14ba86e857b4e7b
Author:     Borislav Petkov <bp@suse.de>
AuthorDate: Tue, 24 Jun 2014 13:25:05 +0200
Committer:  H. Peter Anvin <hpa@linux.intel.com>
CommitDate: Mon, 14 Jul 2014 12:21:40 -0700

x86, cpu: Kill cpu_has_mp

It was used only for checking for some K7s which didn't have MP support,
see

http://www.hardwaresecrets.com/article/How-to-Transform-an-Athlon-XP-into-an-Athlon-MP/24

and it was unconditionally set on 64-bit for no reason. Kill it.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1403609105-8332-4-git-send-email-bp@alien8.de
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
---
 arch/x86/include/asm/cpufeature.h | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 327a061..bb9b258 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -315,7 +315,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 #define cpu_has_avx		boot_cpu_has(X86_FEATURE_AVX)
 #define cpu_has_avx2		boot_cpu_has(X86_FEATURE_AVX2)
 #define cpu_has_ht		boot_cpu_has(X86_FEATURE_HT)
-#define cpu_has_mp		boot_cpu_has(X86_FEATURE_MP)
 #define cpu_has_nx		boot_cpu_has(X86_FEATURE_NX)
 #define cpu_has_k6_mtrr		boot_cpu_has(X86_FEATURE_K6_MTRR)
 #define cpu_has_cyrix_arr	boot_cpu_has(X86_FEATURE_CYRIX_ARR)
@@ -362,9 +361,6 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 #undef  cpu_has_pae
 #define cpu_has_pae		___BUG___
 
-#undef  cpu_has_mp
-#define cpu_has_mp		1
-
 #undef  cpu_has_k6_mtrr
 #define cpu_has_k6_mtrr		0