Straightforward merge. Kind of a pity that gas doesn't really have the
concept of a "long" (long is 4-bytes for some reason.) Nor is it able to
pad to a non-power of two boundary (for struct alignment) to get rid
of the struct alt_instr padding.
Build tested on i386, i386 with lguest & xen paravirt enabled, and
x86_64. Boot tested on x86_64.
Signed-off-by: Kyle McMartin <[EMAIL PROTECTED]>
---
include/asm-x86/alternative.h| 169 +-
include/asm-x86/alternative_32.h | 154 --
include/asm-x86/alternative_64.h | 159 ---
3 files changed, 166 insertions(+), 316 deletions(-)
delete mode 100644 include/asm-x86/alternative_32.h
delete mode 100644 include/asm-x86/alternative_64.h
diff --git a/include/asm-x86/alternative.h b/include/asm-x86/alternative.h
index 9eef6a3..7047a0f 100644
--- a/include/asm-x86/alternative.h
+++ b/include/asm-x86/alternative.h
@@ -1,5 +1,168 @@
-#ifdef CONFIG_X86_32
-# include "alternative_32.h"
+#ifndef _X86_ALTERNATIVE_H
+#define _X86_ALTERNATIVE_H
+
+#ifdef __KERNEL__
+
+#include
+#include
+
+#ifdef CONFIG_X86_64
+# define ALT_ASMPTR".quad"
+# define ALT_ALIGN "8"
+# define ALT_INSTR_PAD 5
#else
-# include "alternative_64.h"
+# define ALT_ASMPTR".long"
+# define ALT_ALIGN "4"
+# define ALT_INSTR_PAD 1
#endif
+
+struct alt_instr {
+ u8 *instr; /* original instruction */
+ u8 *replacement;
+ u8 cpuid; /* cpuid bit set for replacement */
+ u8 instrlen; /* length of original instruction */
+ u8 replacementlen; /* length of new instruction, <= instrlen */
+ u8 _pad[ALT_INSTR_PAD];
+};
+
+/*
+ * Alternative inline assembly for SMP.
+ *
+ * The LOCK_PREFIX macro defined here replaces the LOCK and
+ * LOCK_PREFIX macros used everywhere in the source tree.
+ *
+ * SMP alternatives use the same data structures as the other
+ * alternatives and the X86_FEATURE_UP flag to indicate the case of a
+ * UP system running a SMP kernel. The existing apply_alternatives()
+ * works fine for patching a SMP kernel for UP.
+ *
+ * The SMP alternative tables can be kept after boot and contain both
+ * UP and SMP versions of the instructions to allow switching back to
+ * SMP at runtime, when hotplugging in a new CPU, which is especially
+ * useful in virtualized environments.
+ *
+ * The very common lock prefix is handled as special case in a
+ * separate table which is a pure address list without replacement ptr
+ * and size information. That keeps the table sizes small.
+ */
+
+#ifdef CONFIG_SMP
+#define LOCK_PREFIX \
+ ".section .smp_locks,\"a\"\n" \
+ " .align " ALT_ALIGN "\n" \
+ " " ALT_ASMPTR " 661f\n" /* address */ \
+ ".previous\n" \
+ "661:\n\tlock; "
+#else /* ! CONFIG_SMP */
+#define LOCK_PREFIX ""
+#endif
+
+/* This must be included *after* the definition of LOCK_PREFIX */
+#include
+
+extern void alternative_instructions(void);
+extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+
+struct module;
+
+#ifdef CONFIG_SMP
+extern void alternatives_smp_module_add(struct module *mod, char *name,
+ void *locks, void *locks_end,
+ void *text, void *text_end);
+extern void alternatives_smp_module_del(struct module *mod);
+extern void alternatives_smp_switch(int smp);
+#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) {}
+#endif
+
+#endif
+
+/*
+ * Alternative instructions for different CPU types or capabilities.
+ *
+ * This allows to use optimized instructions even on generic binary
+ * kernels.
+ *
+ * length of oldinstr must be longer or equal the length of newinstr
+ * It can be padded with nops as needed.
+ *
+ * For non barrier like inlines please define new variants
+ * without volatile and memory clobber.
+ */
+#define alternative(oldinstr, newinstr, feature) \
+ asm volatile ("661:\n\t" oldinstr "\n662:\n" \
+ ".section .altinstructions,\"a\"\n"\
+ " .align " ALT_ALIGN " \n" \
+ " " ALT_ASMPTR " 661b\n" /* label */ \
+ " " ALT_ASMPTR " 663f\n" /* new instruction */ \
+ " .byte %c0\n" /* feature bit */\
+ " .byte 662b-661b\n" /* sourcelen */ \
+ " .byte 664f-663f\n" /* replacementlen */ \
+ ".previous\n"
