Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / arm64 / include / asm / alternative.h

diff --git a/kernel/arch/arm64/include/asm/alternative.h b/kernel/arch/arm64/include/asm/alternative.h
new file mode 100644 (file)
index 0000000..d261f01
--- /dev/null
+++ b/kernel/arch/arm64/include/asm/alternative.h
@@ -0,0 +1,44 @@
+#ifndef __ASM_ALTERNATIVE_H
+#define __ASM_ALTERNATIVE_H
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/stringify.h>
+
+struct alt_instr {
+       s32 orig_offset;        /* offset to original instruction */
+       s32 alt_offset;         /* offset to replacement instruction */
+       u16 cpufeature;         /* cpufeature bit set for replacement */
+       u8  orig_len;           /* size of original instruction(s) */
+       u8  alt_len;            /* size of new instruction(s), <= orig_len */
+};
+
+void apply_alternatives_all(void);
+void apply_alternatives(void *start, size_t length);
+void free_alternatives_memory(void);
+
+#define ALTINSTR_ENTRY(feature)                                                      \
+       " .word 661b - .\n"                             /* label           */ \
+       " .word 663f - .\n"                             /* new instruction */ \
+       " .hword " __stringify(feature) "\n"            /* feature bit     */ \
+       " .byte 662b-661b\n"                            /* source len      */ \
+       " .byte 664f-663f\n"                            /* replacement len */
+
+/* alternative assembly primitive: */
+#define ALTERNATIVE(oldinstr, newinstr, feature)                       \
+       "661:\n\t"                                                      \
+       oldinstr "\n"                                                   \
+       "662:\n"                                                        \
+       ".pushsection .altinstructions,\"a\"\n"                         \
+       ALTINSTR_ENTRY(feature)                                         \
+       ".popsection\n"                                                 \
+       ".pushsection .altinstr_replacement, \"a\"\n"                   \
+       "663:\n\t"                                                      \
+       newinstr "\n"                                                   \
+       "664:\n\t"                                                      \
+       ".popsection\n\t"                                               \
+       ".if ((664b-663b) != (662b-661b))\n\t"                          \
+       "       .error \"Alternatives instruction length mismatch\"\n\t"\
+       ".endif\n"
+
+#endif /* __ASM_ALTERNATIVE_H */