1 files changed, 31 insertions, 12 deletions

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 69b74a7b877f..bc6abb7bc7ee 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -28,27 +28,26 @@
  */
 
 #ifdef CONFIG_SMP
-#define LOCK_PREFIX \
+#define LOCK_PREFIX_HERE \
                 ".section .smp_locks,\"a\"\n"   \
-                _ASM_ALIGN "\n"                 \
-                _ASM_PTR "661f\n" /* address */ \
+                ".balign 4\n"                   \
+                ".long 671f - .\n" /* offset */ \
                 ".previous\n"                   \
-                "661:\n\tlock; "
+                "671:"
+
+#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
 
 #else /* ! CONFIG_SMP */
+#define LOCK_PREFIX_HERE ""
 #define LOCK_PREFIX ""
 #endif
 
-/* This must be included *after* the definition of LOCK_PREFIX */
-#include <asm/cpufeature.h>
-
 struct alt_instr {
         u8 *instr;              /* original instruction */
         u8 *replacement;
-        u8  cpuid;              /* cpuid bit set for replacement */
+        u16 cpuid;              /* cpuid bit set for replacement */
         u8  instrlen;           /* length of original instruction */
         u8  replacementlen;     /* length of new instruction, <= instrlen */
-        u8  pad1;
 #ifdef CONFIG_X86_64
         u32 pad2;
 #endif
@@ -65,12 +64,17 @@ extern void alternatives_smp_module_add(struct module *mod, char *name,
                                         void *text, void *text_end);
 extern void alternatives_smp_module_del(struct module *mod);
 extern void alternatives_smp_switch(int smp);
+extern int alternatives_text_reserved(void *start, void *end);
 #else
 static inline void alternatives_smp_module_add(struct module *mod, char *name,
                                                void *locks, void *locks_end,
                                                void *text, void *text_end) {}
 static inline void alternatives_smp_module_del(struct module *mod) {}
 static inline void alternatives_smp_switch(int smp) {}
+static inline int alternatives_text_reserved(void *start, void *end)
+{
+        return 0;
+}
 #endif  /* CONFIG_SMP */
 
 /* alternative assembly primitive: */
@@ -81,9 +85,11 @@ static inline void alternatives_smp_switch(int smp) {}
       _ASM_ALIGN "\n"                                                   \
       _ASM_PTR "661b\n"                         /* label           */   \
       _ASM_PTR "663f\n"                         /* new instruction */   \
-      "  .byte " __stringify(feature) "\n"      /* feature bit     */   \
+      "  .word " __stringify(feature) "\n"      /* feature bit     */   \
       "  .byte 662b-661b\n"                     /* sourcelen       */   \
       "  .byte 664f-663f\n"                     /* replacementlen  */   \
+      ".previous\n"                                                     \
+      ".section .discard,\"aw\",@progbits\n"                            \
       "  .byte 0xff + (664f-663f) - (662b-661b)\n" /* rlen <= slen */   \
       ".previous\n"                                                     \
       ".section .altinstr_replacement, \"ax\"\n"                        \
@@ -91,6 +97,12 @@ static inline void alternatives_smp_switch(int smp) {}
       ".previous"
 
 /*
+ * This must be included *after* the definition of ALTERNATIVE due to
+ * <asm/arch_hweight.h>
+ */
+#include <asm/cpufeature.h>
+
+/*
  * Alternative instructions for different CPU types or capabilities.
  *
  * This allows to use optimized instructions even on generic binary
@@ -125,11 +137,16 @@ static inline void alternatives_smp_switch(int smp) {}
         asm volatile (ALTERNATIVE(oldinstr, newinstr, feature)          \
                 : output : "i" (0), ## input)
 
+/* Like alternative_io, but for replacing a direct call with another one. */
+#define alternative_call(oldfunc, newfunc, feature, output, input...)   \
+        asm volatile (ALTERNATIVE("call %P[old]", "call %P[new]", feature) \
+                : output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
+
 /*
  * use this macro(s) if you need more than one output parameter
  * in alternative_io
  */
-#define ASM_OUTPUT2(a, b) a, b
+#define ASM_OUTPUT2(a...) a
 
 struct paravirt_patch_site;
 #ifdef CONFIG_PARAVIRT
@@ -155,10 +172,12 @@ static inline void apply_paravirt(struct paravirt_patch_site *start,
  * invalid instruction possible) or if the instructions are changed from a
  * consistent state to another consistent state atomically.
  * More care must be taken when modifying code in the SMP case because of
- * Intel's errata.
+ * Intel's errata. text_poke_smp() takes care that errata, but still
+ * doesn't support NMI/MCE handler code modifying.
  * On the local CPU you need to be protected again NMI or MCE handlers seeing an
  * inconsistent instruction while you patch.
  */
 extern void *text_poke(void *addr, const void *opcode, size_t len);
+extern void *text_poke_smp(void *addr, const void *opcode, size_t len);
 
 #endif /* _ASM_X86_ALTERNATIVE_H */