[tip:x86/cpufeature] x86, cpufeature: Convert more "features" to bugs

From: tip-bot for Borislav Petkov
Date: Wed Jun 18 2014 - 18:30:52 EST

Commit-ID: 9b13a93df267af681a66a6a738bf1af10102da7d
Gitweb: http://git.kernel.org/tip/9b13a93df267af681a66a6a738bf1af10102da7d
Author: Borislav Petkov <bp@xxxxxxx>
AuthorDate: Wed, 18 Jun 2014 00:06:23 +0200
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Wed, 18 Jun 2014 15:27:04 -0700

x86, cpufeature: Convert more "features" to bugs

X86_FEATURE_FXSAVE_LEAK, X86_FEATURE_11AP and
X86_FEATURE_CLFLUSH_MONITOR are not really features but synthetic bits
we use for applying different bug workarounds. Call them what they
really are, and make sure they get the proper cross-CPU behavior (OR
rather than AND).

Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Link: http://lkml.kernel.org/r/1403042783-23278-1-git-send-email-bp@xxxxxxxxx
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/include/asm/apic.h | 2 +-
arch/x86/include/asm/cpufeature.h | 31 +++++++++++++++++--------------
arch/x86/include/asm/fpu-internal.h | 2 +-
arch/x86/include/asm/mwait.h | 2 +-
arch/x86/kernel/cpu/amd.c | 2 +-
arch/x86/kernel/cpu/intel.c | 4 ++--
6 files changed, 23 insertions(+), 20 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 19b0eba..79752f2 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -99,7 +99,7 @@ static inline void native_apic_mem_write(u32 reg, u32 v)
{
volatile u32 *addr = (volatile u32 *)(APIC_BASE + reg);

- alternative_io("movl %0, %1", "xchgl %0, %1", X86_FEATURE_11AP,
+ alternative_io("movl %0, %1", "xchgl %0, %1", X86_BUG_11AP,
ASM_OUTPUT2("=r" (v), "=m" (*addr)),
ASM_OUTPUT2("0" (v), "m" (*addr)));
}
diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index b82f951..52df22b 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -81,7 +81,7 @@
#define X86_FEATURE_P4 ( 3*32+ 7) /* "" P4 */
#define X86_FEATURE_CONSTANT_TSC ( 3*32+ 8) /* TSC ticks at a constant rate */
#define X86_FEATURE_UP ( 3*32+ 9) /* smp kernel running on up */
-#define X86_FEATURE_FXSAVE_LEAK ( 3*32+10) /* "" FXSAVE leaks FOP/FIP/FOP */
+/* free, was #define X86_FEATURE_FXSAVE_LEAK ( 3*32+10) * "" FXSAVE leaks FOP/FIP/FOP */
#define X86_FEATURE_ARCH_PERFMON ( 3*32+11) /* Intel Architectural PerfMon */
#define X86_FEATURE_PEBS ( 3*32+12) /* Precise-Event Based Sampling */
#define X86_FEATURE_BTS ( 3*32+13) /* Branch Trace Store */
@@ -90,13 +90,13 @@
#define X86_FEATURE_REP_GOOD ( 3*32+16) /* rep microcode works well */
#define X86_FEATURE_MFENCE_RDTSC ( 3*32+17) /* "" Mfence synchronizes RDTSC */
#define X86_FEATURE_LFENCE_RDTSC ( 3*32+18) /* "" Lfence synchronizes RDTSC */
-#define X86_FEATURE_11AP ( 3*32+19) /* "" Bad local APIC aka 11AP */
+/* free, was #define X86_FEATURE_11AP ( 3*32+19) * "" Bad local APIC aka 11AP */
#define X86_FEATURE_NOPL ( 3*32+20) /* The NOPL (0F 1F) instructions */
#define X86_FEATURE_ALWAYS ( 3*32+21) /* "" Always-present feature */
#define X86_FEATURE_XTOPOLOGY ( 3*32+22) /* cpu topology enum extensions */
#define X86_FEATURE_TSC_RELIABLE ( 3*32+23) /* TSC is known to be reliable */
#define X86_FEATURE_NONSTOP_TSC ( 3*32+24) /* TSC does not stop in C states */
-#define X86_FEATURE_CLFLUSH_MONITOR ( 3*32+25) /* "" clflush reqd with monitor */
+/* free, was #define X86_FEATURE_CLFLUSH_MONITOR ( 3*32+25) * "" clflush reqd with monitor */
#define X86_FEATURE_EXTD_APICID ( 3*32+26) /* has extended APICID (8 bits) */
#define X86_FEATURE_AMD_DCM ( 3*32+27) /* multi-node processor */
#define X86_FEATURE_APERFMPERF ( 3*32+28) /* APERFMPERF */
@@ -241,6 +241,9 @@
#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_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 */

#if defined(__KERNEL__) && !defined(__ASSEMBLY__)

@@ -545,20 +548,20 @@ static __always_inline __pure bool _static_cpu_has_safe(u16 bit)
#define static_cpu_has_safe(bit) boot_cpu_has(bit)
#endif

-#define cpu_has_bug(c, bit) cpu_has(c, (bit))
-#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
-#define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit));
+#define cpu_has_bug(c, bit) cpu_has(c, (bit))
+#define set_cpu_bug(c, bit) set_cpu_cap(c, (bit))
+#define clear_cpu_bug(c, bit) clear_cpu_cap(c, (bit))

-#define static_cpu_has_bug(bit) static_cpu_has((bit))
-#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))
+#define static_cpu_has_bug(bit) static_cpu_has((bit))
+#define static_cpu_has_bug_safe(bit) static_cpu_has_safe((bit))
+#define boot_cpu_has_bug(bit) cpu_has_bug(&boot_cpu_data, (bit))

-#define MAX_CPU_FEATURES (NCAPINTS * 32)
-#define cpu_have_feature boot_cpu_has
+#define MAX_CPU_FEATURES (NCAPINTS * 32)
+#define cpu_have_feature boot_cpu_has

-#define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
-#define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
- boot_cpu_data.x86_model
+#define CPU_FEATURE_TYPEFMT "x86,ven%04Xfam%04Xmod%04X"
+#define CPU_FEATURE_TYPEVAL boot_cpu_data.x86_vendor, boot_cpu_data.x86, \
+ boot_cpu_data.x86_model

#endif /* defined(__KERNEL__) && !defined(__ASSEMBLY__) */
-
#endif /* _ASM_X86_CPUFEATURE_H */
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 115e368..e3b8542 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -293,7 +293,7 @@ static inline int restore_fpu_checking(struct task_struct *tsk)
/* AMD K7/K8 CPUs don't save/restore FDP/FIP/FOP unless an exception
is pending. Clear the x87 state here by setting it to fixed
values. "m" is a random variable that should be in L1 */
- if (unlikely(static_cpu_has_safe(X86_FEATURE_FXSAVE_LEAK))) {
+ if (unlikely(static_cpu_has_bug_safe(X86_BUG_FXSAVE_LEAK))) {
asm volatile(
"fnclex\n\t"
"emms\n\t"
diff --git a/arch/x86/include/asm/mwait.h b/arch/x86/include/asm/mwait.h
index 1da25a5..a1410db 100644
--- a/arch/x86/include/asm/mwait.h
+++ b/arch/x86/include/asm/mwait.h
@@ -43,7 +43,7 @@ static inline void __mwait(unsigned long eax, unsigned long ecx)
static inline void mwait_idle_with_hints(unsigned long eax, unsigned long ecx)
{
if (!current_set_polling_and_test()) {
- if (static_cpu_has(X86_FEATURE_CLFLUSH_MONITOR)) {
+ if (static_cpu_has_bug(X86_BUG_CLFLUSH_MONITOR)) {
mb();
clflush((void *)&current_thread_info()->flags);
mb();
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c
index ce8b8ff..8714a78 100644
--- a/arch/x86/kernel/cpu/amd.c
+++ b/arch/x86/kernel/cpu/amd.c
@@ -595,7 +595,7 @@ static void init_amd(struct cpuinfo_x86 *c)

/* Enable workaround for FXSAVE leak */
if (c->x86 >= 6)
- set_cpu_cap(c, X86_FEATURE_FXSAVE_LEAK);
+ set_cpu_bug(c, X86_BUG_FXSAVE_LEAK);

if (!c->x86_model_id[0]) {
switch (c->x86) {
diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index a800290..0fd9557 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -253,7 +253,7 @@ static void intel_workarounds(struct cpuinfo_x86 *c)
*/
if (cpu_has_apic && (c->x86<<8 | c->x86_model<<4) == 0x520 &&
(c->x86_mask < 0x6 || c->x86_mask == 0xb))
- set_cpu_cap(c, X86_FEATURE_11AP);
+ set_cpu_bug(c, X86_BUG_11AP);


#ifdef CONFIG_X86_INTEL_USERCOPY
@@ -391,7 +391,7 @@ static void init_intel(struct cpuinfo_x86 *c)

if (c->x86 == 6 && cpu_has_clflush &&
(c->x86_model == 29 || c->x86_model == 46 || c->x86_model == 47))
- set_cpu_cap(c, X86_FEATURE_CLFLUSH_MONITOR);
+ set_cpu_bug(c, X86_BUG_CLFLUSH_MONITOR);

#ifdef CONFIG_X86_64
if (c->x86 == 15)
--
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