[GIT PULL] x86/asm for 2.6.36

From: H. Peter Anvin
Date: Thu Aug 05 2010 - 16:41:16 EST


Hi Linus,

The following changes since commit cdd854bc42b5e6c79bbbc40c6600d995ffe6e747:

Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc (2010-08-05 09:03:46 -0700)

are available in the git repository at:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip.git x86-asm-for-linus

Brian Gerst (5):
x86: Remove redundant K6 MSRs
x86: Use symbolic MSR names
x86-64: Simplify loading initial_gs
x86-64, asm: Directly access per-cpu IST
x86-32, asm: Directly access per-cpu GDT

H. Peter Anvin (7):
x86: Add memory modify constraints to xchg() and cmpxchg()
Merge remote branch 'origin/x86/urgent' into x86/asm
x86, asm: Clean up and simplify set_64bit()
x86, asm: Clean up and simplify <asm/cmpxchg.h>
x86, asm: Move cmpxchg emulation code to arch/x86/lib
x86, asm: Merge cmpxchg_486_u64() and cmpxchg8b_emu()
um, x86: Cast to (u64 *) inside set_64bit()

arch/um/include/asm/pgtable-3level.h | 4 +-
arch/x86/include/asm/cmpxchg_32.h | 198 ++++++++++++++-----------------
arch/x86/include/asm/cmpxchg_64.h | 83 +++++++++-----
arch/x86/include/asm/msr-index.h | 2 -
arch/x86/kernel/acpi/realmode/wakeup.S | 2 +-
arch/x86/kernel/cpu/Makefile | 2 +-
arch/x86/kernel/entry_32.S | 11 +-
arch/x86/kernel/entry_64.S | 6 +-
arch/x86/kernel/head_64.S | 5 +-
arch/x86/kernel/verify_cpu_64.S | 3 +-
arch/x86/kvm/svm.c | 6 +-
arch/x86/kvm/vmx.c | 8 +-
arch/x86/kvm/x86.c | 2 +-
arch/x86/lib/Makefile | 1 +
arch/x86/{kernel/cpu => lib}/cmpxchg.c | 18 ---
15 files changed, 166 insertions(+), 185 deletions(-)
rename arch/x86/{kernel/cpu => lib}/cmpxchg.c (75%)

diff --git a/arch/um/include/asm/pgtable-3level.h b/arch/um/include/asm/pgtable-3level.h
index 084de4a..0032f92 100644
--- a/arch/um/include/asm/pgtable-3level.h
+++ b/arch/um/include/asm/pgtable-3level.h
@@ -60,7 +60,7 @@
set_pud(pud, __pud(_PAGE_TABLE + __pa(pmd)))

#ifdef CONFIG_64BIT
-#define set_pud(pudptr, pudval) set_64bit((phys_t *) (pudptr), pud_val(pudval))
+#define set_pud(pudptr, pudval) set_64bit((u64 *) (pudptr), pud_val(pudval))
#else
#define set_pud(pudptr, pudval) (*(pudptr) = (pudval))
#endif
@@ -73,7 +73,7 @@ static inline int pgd_newpage(pgd_t pgd)
static inline void pgd_mkuptodate(pgd_t pgd) { pgd_val(pgd) &= ~_PAGE_NEWPAGE; }

#ifdef CONFIG_64BIT
-#define set_pmd(pmdptr, pmdval) set_64bit((phys_t *) (pmdptr), pmd_val(pmdval))
+#define set_pmd(pmdptr, pmdval) set_64bit((u64 *) (pmdptr), pmd_val(pmdval))
#else
#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval))
#endif
diff --git a/arch/x86/include/asm/cmpxchg_32.h b/arch/x86/include/asm/cmpxchg_32.h
index 8859e12..284a6e8 100644
--- a/arch/x86/include/asm/cmpxchg_32.h
+++ b/arch/x86/include/asm/cmpxchg_32.h
@@ -11,38 +11,42 @@
extern void __xchg_wrong_size(void);

/*
- * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
- * Note 2: xchg has side effect, so that attribute volatile is necessary,
- * but generally the primitive is invalid, *ptr is output argument. --ANK
+ * Note: no "lock" prefix even on SMP: xchg always implies lock anyway.
+ * Since this is generally used to protect other memory information, we
+ * use "asm volatile" and "memory" clobbers to prevent gcc from moving
+ * information around.
*/
-
-struct __xchg_dummy {
- unsigned long a[100];
-};
-#define __xg(x) ((struct __xchg_dummy *)(x))
-
#define __xchg(x, ptr, size) \
({ \
__typeof(*(ptr)) __x = (x); \
switch (size) { \
case 1: \
- asm volatile("xchgb %b0,%1" \
- : "=q" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ { \
+ volatile u8 *__ptr = (volatile u8 *)(ptr); \
+ asm volatile("xchgb %0,%1" \
+ : "=q" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
case 2: \
- asm volatile("xchgw %w0,%1" \
- : "=r" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ { \
+ volatile u16 *__ptr = (volatile u16 *)(ptr); \
+ asm volatile("xchgw %0,%1" \
+ : "=r" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
case 4: \
+ { \
+ volatile u32 *__ptr = (volatile u32 *)(ptr); \
asm volatile("xchgl %0,%1" \
- : "=r" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ : "=r" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
default: \
__xchg_wrong_size(); \
} \
@@ -53,60 +57,33 @@ struct __xchg_dummy {
__xchg((v), (ptr), sizeof(*ptr))

/*
- * The semantics of XCHGCMP8B are a bit strange, this is why
- * there is a loop and the loading of %%eax and %%edx has to
- * be inside. This inlines well in most cases, the cached
- * cost is around ~38 cycles. (in the future we might want
- * to do an SIMD/3DNOW!/MMX/FPU 64-bit store here, but that
- * might have an implicit FPU-save as a cost, so it's not
- * clear which path to go.)
+ * CMPXCHG8B only writes to the target if we had the previous
+ * value in registers, otherwise it acts as a read and gives us the
+ * "new previous" value. That is why there is a loop. Preloading
+ * EDX:EAX is a performance optimization: in the common case it means
+ * we need only one locked operation.
*
- * cmpxchg8b must be used with the lock prefix here to allow
- * the instruction to be executed atomically, see page 3-102
- * of the instruction set reference 24319102.pdf. We need
- * the reader side to see the coherent 64bit value.
+ * A SIMD/3DNOW!/MMX/FPU 64-bit store here would require at the very
+ * least an FPU save and/or %cr0.ts manipulation.
+ *
+ * cmpxchg8b must be used with the lock prefix here to allow the
+ * instruction to be executed atomically. We need to have the reader
+ * side to see the coherent 64bit value.
*/
-static inline void __set_64bit(unsigned long long *ptr,
- unsigned int low, unsigned int high)
+static inline void set_64bit(volatile u64 *ptr, u64 value)
{
+ u32 low = value;
+ u32 high = value >> 32;
+ u64 prev = *ptr;
+
asm volatile("\n1:\t"
- "movl (%0), %%eax\n\t"
- "movl 4(%0), %%edx\n\t"
- LOCK_PREFIX "cmpxchg8b (%0)\n\t"
+ LOCK_PREFIX "cmpxchg8b %0\n\t"
"jnz 1b"
- : /* no outputs */
- : "D"(ptr),
- "b"(low),
- "c"(high)
- : "ax", "dx", "memory");
-}
-
-static inline void __set_64bit_constant(unsigned long long *ptr,
- unsigned long long value)
-{
- __set_64bit(ptr, (unsigned int)value, (unsigned int)(value >> 32));
-}
-
-#define ll_low(x) *(((unsigned int *)&(x)) + 0)
-#define ll_high(x) *(((unsigned int *)&(x)) + 1)
-
-static inline void __set_64bit_var(unsigned long long *ptr,
- unsigned long long value)
-{
- __set_64bit(ptr, ll_low(value), ll_high(value));
+ : "=m" (*ptr), "+A" (prev)
+ : "b" (low), "c" (high)
+ : "memory");
}

-#define set_64bit(ptr, value) \
- (__builtin_constant_p((value)) \
- ? __set_64bit_constant((ptr), (value)) \
- : __set_64bit_var((ptr), (value)))
-
-#define _set_64bit(ptr, value) \
- (__builtin_constant_p(value) \
- ? __set_64bit(ptr, (unsigned int)(value), \
- (unsigned int)((value) >> 32)) \
- : __set_64bit(ptr, ll_low((value)), ll_high((value))))
-
extern void __cmpxchg_wrong_size(void);

/*
@@ -121,23 +98,32 @@ extern void __cmpxchg_wrong_size(void);
__typeof__(*(ptr)) __new = (new); \
switch (size) { \
case 1: \
- asm volatile(lock "cmpxchgb %b1,%2" \
- : "=a"(__ret) \
- : "q"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u8 *__ptr = (volatile u8 *)(ptr); \
+ asm volatile(lock "cmpxchgb %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "q" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
case 2: \
- asm volatile(lock "cmpxchgw %w1,%2" \
- : "=a"(__ret) \
- : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u16 *__ptr = (volatile u16 *)(ptr); \
+ asm volatile(lock "cmpxchgw %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "r" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
case 4: \
- asm volatile(lock "cmpxchgl %1,%2" \
- : "=a"(__ret) \
- : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u32 *__ptr = (volatile u32 *)(ptr); \
+ asm volatile(lock "cmpxchgl %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "r" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
default: \
__cmpxchg_wrong_size(); \
} \
@@ -175,32 +161,28 @@ extern void __cmpxchg_wrong_size(void);
(unsigned long long)(n)))
#endif

-static inline unsigned long long __cmpxchg64(volatile void *ptr,
- unsigned long long old,
- unsigned long long new)
+static inline u64 __cmpxchg64(volatile u64 *ptr, u64 old, u64 new)
{
- unsigned long long prev;
- asm volatile(LOCK_PREFIX "cmpxchg8b %3"
- : "=A"(prev)
- : "b"((unsigned long)new),
- "c"((unsigned long)(new >> 32)),
- "m"(*__xg(ptr)),
- "0"(old)
+ u64 prev;
+ asm volatile(LOCK_PREFIX "cmpxchg8b %1"
+ : "=A" (prev),
+ "+m" (*ptr)
+ : "b" ((u32)new),
+ "c" ((u32)(new >> 32)),
+ "0" (old)
: "memory");
return prev;
}

-static inline unsigned long long __cmpxchg64_local(volatile void *ptr,
- unsigned long long old,
- unsigned long long new)
+static inline u64 __cmpxchg64_local(volatile u64 *ptr, u64 old, u64 new)
{
- unsigned long long prev;
- asm volatile("cmpxchg8b %3"
- : "=A"(prev)
- : "b"((unsigned long)new),
- "c"((unsigned long)(new >> 32)),
- "m"(*__xg(ptr)),
- "0"(old)
+ u64 prev;
+ asm volatile("cmpxchg8b %1"
+ : "=A" (prev),
+ "+m" (*ptr)
+ : "b" ((u32)new),
+ "c" ((u32)(new >> 32)),
+ "0" (old)
: "memory");
return prev;
}
@@ -264,8 +246,6 @@ static inline unsigned long cmpxchg_386(volatile void *ptr, unsigned long old,
* to simulate the cmpxchg8b on the 80386 and 80486 CPU.
*/

-extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64);
-
#define cmpxchg64(ptr, o, n) \
({ \
__typeof__(*(ptr)) __ret; \
@@ -283,20 +263,20 @@ extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64);
__ret; })


-
-#define cmpxchg64_local(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) __ret; \
- if (likely(boot_cpu_data.x86 > 4)) \
- __ret = (__typeof__(*(ptr)))__cmpxchg64_local((ptr), \
- (unsigned long long)(o), \
- (unsigned long long)(n)); \
- else \
- __ret = (__typeof__(*(ptr)))cmpxchg_486_u64((ptr), \
- (unsigned long long)(o), \
- (unsigned long long)(n)); \
- __ret; \
-})
+#define cmpxchg64_local(ptr, o, n) \
+({ \
+ __typeof__(*(ptr)) __ret; \
+ __typeof__(*(ptr)) __old = (o); \
+ __typeof__(*(ptr)) __new = (n); \
+ alternative_io("call cmpxchg8b_emu", \
+ "cmpxchg8b (%%esi)" , \
+ X86_FEATURE_CX8, \
+ "=A" (__ret), \
+ "S" ((ptr)), "0" (__old), \
+ "b" ((unsigned int)__new), \
+ "c" ((unsigned int)(__new>>32)) \
+ : "memory"); \
+ __ret; })

#endif

diff --git a/arch/x86/include/asm/cmpxchg_64.h b/arch/x86/include/asm/cmpxchg_64.h
index 485ae41..423ae58 100644
--- a/arch/x86/include/asm/cmpxchg_64.h
+++ b/arch/x86/include/asm/cmpxchg_64.h
@@ -3,51 +3,60 @@

#include <asm/alternative.h> /* Provides LOCK_PREFIX */

-#define __xg(x) ((volatile long *)(x))
-
-static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
+static inline void set_64bit(volatile u64 *ptr, u64 val)
{
*ptr = val;
}

-#define _set_64bit set_64bit
-
extern void __xchg_wrong_size(void);
extern void __cmpxchg_wrong_size(void);

/*
- * Note: no "lock" prefix even on SMP: xchg always implies lock anyway
- * Note 2: xchg has side effect, so that attribute volatile is necessary,
- * but generally the primitive is invalid, *ptr is output argument. --ANK
+ * Note: no "lock" prefix even on SMP: xchg always implies lock anyway.
+ * Since this is generally used to protect other memory information, we
+ * use "asm volatile" and "memory" clobbers to prevent gcc from moving
+ * information around.
*/
#define __xchg(x, ptr, size) \
({ \
__typeof(*(ptr)) __x = (x); \
switch (size) { \
case 1: \
- asm volatile("xchgb %b0,%1" \
- : "=q" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ { \
+ volatile u8 *__ptr = (volatile u8 *)(ptr); \
+ asm volatile("xchgb %0,%1" \
+ : "=q" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
case 2: \
- asm volatile("xchgw %w0,%1" \
- : "=r" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ { \
+ volatile u16 *__ptr = (volatile u16 *)(ptr); \
+ asm volatile("xchgw %0,%1" \
+ : "=r" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
case 4: \
- asm volatile("xchgl %k0,%1" \
- : "=r" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ { \
+ volatile u32 *__ptr = (volatile u32 *)(ptr); \
+ asm volatile("xchgl %0,%1" \
+ : "=r" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
case 8: \
+ { \
+ volatile u64 *__ptr = (volatile u64 *)(ptr); \
asm volatile("xchgq %0,%1" \
- : "=r" (__x) \
- : "m" (*__xg(ptr)), "0" (__x) \
+ : "=r" (__x), "+m" (*__ptr) \
+ : "0" (__x) \
: "memory"); \
break; \
+ } \
default: \
__xchg_wrong_size(); \
} \
@@ -71,29 +80,41 @@ extern void __cmpxchg_wrong_size(void);
__typeof__(*(ptr)) __new = (new); \
switch (size) { \
case 1: \
- asm volatile(lock "cmpxchgb %b1,%2" \
- : "=a"(__ret) \
- : "q"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u8 *__ptr = (volatile u8 *)(ptr); \
+ asm volatile(lock "cmpxchgb %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "q" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
case 2: \
- asm volatile(lock "cmpxchgw %w1,%2" \
- : "=a"(__ret) \
- : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u16 *__ptr = (volatile u16 *)(ptr); \
+ asm volatile(lock "cmpxchgw %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "r" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
case 4: \
- asm volatile(lock "cmpxchgl %k1,%2" \
- : "=a"(__ret) \
- : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u32 *__ptr = (volatile u32 *)(ptr); \
+ asm volatile(lock "cmpxchgl %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "r" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
case 8: \
- asm volatile(lock "cmpxchgq %1,%2" \
- : "=a"(__ret) \
- : "r"(__new), "m"(*__xg(ptr)), "0"(__old) \
+ { \
+ volatile u64 *__ptr = (volatile u64 *)(ptr); \
+ asm volatile(lock "cmpxchgq %2,%1" \
+ : "=a" (__ret), "+m" (*__ptr) \
+ : "r" (__new), "0" (__old) \
: "memory"); \
break; \
+ } \
default: \
__cmpxchg_wrong_size(); \
} \
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index 509a421..b27d160 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -161,8 +161,6 @@
#define MSR_K7_FID_VID_STATUS 0xc0010042

/* K6 MSRs */
-#define MSR_K6_EFER 0xc0000080
-#define MSR_K6_STAR 0xc0000081
#define MSR_K6_WHCR 0xc0000082
#define MSR_K6_UWCCR 0xc0000085
#define MSR_K6_EPMR 0xc0000086
diff --git a/arch/x86/kernel/acpi/realmode/wakeup.S b/arch/x86/kernel/acpi/realmode/wakeup.S
index 580b4e2..28595d6 100644
--- a/arch/x86/kernel/acpi/realmode/wakeup.S
+++ b/arch/x86/kernel/acpi/realmode/wakeup.S
@@ -104,7 +104,7 @@ _start:
movl %eax, %ecx
orl %edx, %ecx
jz 1f
- movl $0xc0000080, %ecx
+ movl $MSR_EFER, %ecx
wrmsr
1:

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index 3a785da..c47c439 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -16,7 +16,7 @@ obj-y := intel_cacheinfo.o addon_cpuid_features.o
obj-y += proc.o capflags.o powerflags.o common.o
obj-y += vmware.o hypervisor.o sched.o mshyperv.o

-obj-$(CONFIG_X86_32) += bugs.o cmpxchg.o
+obj-$(CONFIG_X86_32) += bugs.o
obj-$(CONFIG_X86_64) += bugs_64.o

obj-$(CONFIG_CPU_SUP_INTEL) += intel.o
diff --git a/arch/x86/kernel/cpu/cmpxchg.c b/arch/x86/kernel/cpu/cmpxchg.c
deleted file mode 100644
index 2056ccf..0000000
--- a/arch/x86/kernel/cpu/cmpxchg.c
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * cmpxchg*() fallbacks for CPU not supporting these instructions
- */
-
-#include <linux/kernel.h>
-#include <linux/smp.h>
-#include <linux/module.h>
-
-#ifndef CONFIG_X86_CMPXCHG
-unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
-{
- u8 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg for 386. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u8 *)ptr;
- if (prev == old)
- *(u8 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_386_u8);
-
-unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
-{
- u16 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg for 386. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u16 *)ptr;
- if (prev == old)
- *(u16 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_386_u16);
-
-unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
-{
- u32 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg for 386. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u32 *)ptr;
- if (prev == old)
- *(u32 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_386_u32);
-#endif
-
-#ifndef CONFIG_X86_CMPXCHG64
-unsigned long long cmpxchg_486_u64(volatile void *ptr, u64 old, u64 new)
-{
- u64 prev;
- unsigned long flags;
-
- /* Poor man's cmpxchg8b for 386 and 486. Unsuitable for SMP */
- local_irq_save(flags);
- prev = *(u64 *)ptr;
- if (prev == old)
- *(u64 *)ptr = new;
- local_irq_restore(flags);
- return prev;
-}
-EXPORT_SYMBOL(cmpxchg_486_u64);
-#endif
-
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index cd49141..233c582 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -611,14 +611,14 @@ ldt_ss:
* compensating for the offset by changing to the ESPFIX segment with
* a base address that matches for the difference.
*/
+#define GDT_ESPFIX_SS PER_CPU_VAR(gdt_page) + (GDT_ENTRY_ESPFIX_SS * 8)
mov %esp, %edx /* load kernel esp */
mov PT_OLDESP(%esp), %eax /* load userspace esp */
mov %dx, %ax /* eax: new kernel esp */
sub %eax, %edx /* offset (low word is 0) */
- PER_CPU(gdt_page, %ebx)
shr $16, %edx
- mov %dl, GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx) /* bits 16..23 */
- mov %dh, GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx) /* bits 24..31 */
+ mov %dl, GDT_ESPFIX_SS + 4 /* bits 16..23 */
+ mov %dh, GDT_ESPFIX_SS + 7 /* bits 24..31 */
pushl $__ESPFIX_SS
CFI_ADJUST_CFA_OFFSET 4
push %eax /* new kernel esp */
@@ -791,9 +791,8 @@ ptregs_clone:
* normal stack and adjusts ESP with the matching offset.
*/
/* fixup the stack */
- PER_CPU(gdt_page, %ebx)
- mov GDT_ENTRY_ESPFIX_SS * 8 + 4(%ebx), %al /* bits 16..23 */
- mov GDT_ENTRY_ESPFIX_SS * 8 + 7(%ebx), %ah /* bits 24..31 */
+ mov GDT_ESPFIX_SS + 4, %al /* bits 16..23 */
+ mov GDT_ESPFIX_SS + 7, %ah /* bits 24..31 */
shl $16, %eax
addl %esp, %eax /* the adjusted stack pointer */
pushl $__KERNEL_DS
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index 4db7c4d..59af275 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1065,6 +1065,7 @@ ENTRY(\sym)
END(\sym)
.endm

+#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8)
.macro paranoidzeroentry_ist sym do_sym ist
ENTRY(\sym)
INTR_FRAME
@@ -1076,10 +1077,9 @@ ENTRY(\sym)
TRACE_IRQS_OFF
movq %rsp,%rdi /* pt_regs pointer */
xorl %esi,%esi /* no error code */
- PER_CPU(init_tss, %r12)
- subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
+ subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
call \do_sym
- addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12)
+ addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist)
jmp paranoid_exit /* %ebx: no swapgs flag */
CFI_ENDPROC
END(\sym)
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 3d1e6f1..239046b 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -234,9 +234,8 @@ ENTRY(secondary_startup_64)
* init data section till per cpu areas are set up.
*/
movl $MSR_GS_BASE,%ecx
- movq initial_gs(%rip),%rax
- movq %rax,%rdx
- shrq $32,%rdx
+ movl initial_gs(%rip),%eax
+ movl initial_gs+4(%rip),%edx
wrmsr

/* esi is pointer to real mode structure with interesting info.
diff --git a/arch/x86/kernel/verify_cpu_64.S b/arch/x86/kernel/verify_cpu_64.S
index 45b6f8a..56a8c2a 100644
--- a/arch/x86/kernel/verify_cpu_64.S
+++ b/arch/x86/kernel/verify_cpu_64.S
@@ -31,6 +31,7 @@
*/

#include <asm/cpufeature.h>
+#include <asm/msr-index.h>

verify_cpu:
pushfl # Save caller passed flags
@@ -88,7 +89,7 @@ verify_cpu_sse_test:
je verify_cpu_sse_ok
test %di,%di
jz verify_cpu_no_longmode # only try to force SSE on AMD
- movl $0xc0010015,%ecx # HWCR
+ movl $MSR_K7_HWCR,%ecx
rdmsr
btr $15,%eax # enable SSE
wrmsr
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 56c9b6b..2636ea8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -131,7 +131,7 @@ static struct svm_direct_access_msrs {
u32 index; /* Index of the MSR */
bool always; /* True if intercept is always on */
} direct_access_msrs[] = {
- { .index = MSR_K6_STAR, .always = true },
+ { .index = MSR_STAR, .always = true },
{ .index = MSR_IA32_SYSENTER_CS, .always = true },
#ifdef CONFIG_X86_64
{ .index = MSR_GS_BASE, .always = true },
@@ -2433,7 +2433,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 *data)
*data = tsc_offset + native_read_tsc();
break;
}
- case MSR_K6_STAR:
+ case MSR_STAR:
*data = svm->vmcb->save.star;
break;
#ifdef CONFIG_X86_64
@@ -2557,7 +2557,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, unsigned ecx, u64 data)

break;
}
- case MSR_K6_STAR:
+ case MSR_STAR:
svm->vmcb->save.star = data;
break;
#ifdef CONFIG_X86_64
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 27a0222..49b25ee 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -240,14 +240,14 @@ static u64 host_efer;
static void ept_save_pdptrs(struct kvm_vcpu *vcpu);

/*
- * Keep MSR_K6_STAR at the end, as setup_msrs() will try to optimize it
+ * Keep MSR_STAR at the end, as setup_msrs() will try to optimize it
* away by decrementing the array size.
*/
static const u32 vmx_msr_index[] = {
#ifdef CONFIG_X86_64
MSR_SYSCALL_MASK, MSR_LSTAR, MSR_CSTAR,
#endif
- MSR_EFER, MSR_TSC_AUX, MSR_K6_STAR,
+ MSR_EFER, MSR_TSC_AUX, MSR_STAR,
};
#define NR_VMX_MSR ARRAY_SIZE(vmx_msr_index)

@@ -1117,10 +1117,10 @@ static void setup_msrs(struct vcpu_vmx *vmx)
if (index >= 0 && vmx->rdtscp_enabled)
move_msr_up(vmx, index, save_nmsrs++);
/*
- * MSR_K6_STAR is only needed on long mode guests, and only
+ * MSR_STAR is only needed on long mode guests, and only
* if efer.sce is enabled.
*/
- index = __find_msr_index(vmx, MSR_K6_STAR);
+ index = __find_msr_index(vmx, MSR_STAR);
if ((index >= 0) && (vmx->vcpu.arch.efer & EFER_SCE))
move_msr_up(vmx, index, save_nmsrs++);
}
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 97aab03..25f1907 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -733,7 +733,7 @@ static u32 msrs_to_save[] = {
HV_X64_MSR_GUEST_OS_ID, HV_X64_MSR_HYPERCALL,
HV_X64_MSR_APIC_ASSIST_PAGE,
MSR_IA32_SYSENTER_CS, MSR_IA32_SYSENTER_ESP, MSR_IA32_SYSENTER_EIP,
- MSR_K6_STAR,
+ MSR_STAR,
#ifdef CONFIG_X86_64
MSR_CSTAR, MSR_KERNEL_GS_BASE, MSR_SYSCALL_MASK, MSR_LSTAR,
#endif
diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile
index f871e04..e10cf07 100644
--- a/arch/x86/lib/Makefile
+++ b/arch/x86/lib/Makefile
@@ -30,6 +30,7 @@ ifeq ($(CONFIG_X86_32),y)
lib-y += checksum_32.o
lib-y += strstr_32.o
lib-y += semaphore_32.o string_32.o
+ lib-y += cmpxchg.o
ifneq ($(CONFIG_X86_CMPXCHG64),y)
lib-y += cmpxchg8b_emu.o atomic64_386_32.o
endif
diff --git a/arch/x86/lib/cmpxchg.c b/arch/x86/lib/cmpxchg.c
new file mode 100644
index 0000000..5d619f6
--- /dev/null
+++ b/arch/x86/lib/cmpxchg.c
@@ -0,0 +1,54 @@
+/*
+ * cmpxchg*() fallbacks for CPU not supporting these instructions
+ */
+
+#include <linux/kernel.h>
+#include <linux/smp.h>
+#include <linux/module.h>
+
+#ifndef CONFIG_X86_CMPXCHG
+unsigned long cmpxchg_386_u8(volatile void *ptr, u8 old, u8 new)
+{
+ u8 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg for 386. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u8 *)ptr;
+ if (prev == old)
+ *(u8 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_386_u8);
+
+unsigned long cmpxchg_386_u16(volatile void *ptr, u16 old, u16 new)
+{
+ u16 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg for 386. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u16 *)ptr;
+ if (prev == old)
+ *(u16 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_386_u16);
+
+unsigned long cmpxchg_386_u32(volatile void *ptr, u32 old, u32 new)
+{
+ u32 prev;
+ unsigned long flags;
+
+ /* Poor man's cmpxchg for 386. Unsuitable for SMP */
+ local_irq_save(flags);
+ prev = *(u32 *)ptr;
+ if (prev == old)
+ *(u32 *)ptr = new;
+ local_irq_restore(flags);
+ return prev;
+}
+EXPORT_SYMBOL(cmpxchg_386_u32);
+#endif
--
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