[MIPS] Improve branch prediction in ll/sc atomic operations.

[pandora-kernel.git] / include / asm-mips / bitops.h

diff --git a/include/asm-mips/bitops.h b/include/asm-mips/bitops.h
index 06445de..06c0822 100644 (file)
--- a/include/asm-mips/bitops.h
+++ b/include/asm-mips/bitops.h
@@ -68,7 +68,10 @@ static inline void set_bit(unsigned long nr, volatile unsigned long *addr)
                "1:     " __LL "%0, %1                  # set_bit       \n"
                "       or      %0, %2                                  \n"
                "       " __SC  "%0, %1                                 \n"
-               "       beqz    %0, 1b                                  \n"
+               "       beqz    %0, 2f                                  \n"
+               "       .subsection 2                                   \n"
+               "2:     b       1b                                      \n"
+               "       .previous                                       \n"
                "       .set    mips0                                   \n"
                : "=&r" (temp), "=m" (*m)
                : "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
@@ -116,7 +119,10 @@ static inline void clear_bit(unsigned long nr, volatile unsigned long *addr)
                "1:     " __LL "%0, %1                  # clear_bit     \n"
                "       and     %0, %2                                  \n"
                "       " __SC "%0, %1                                  \n"
-               "       beqz    %0, 1b                                  \n"
+               "       beqz    %0, 2f                                  \n"
+               "       .subsection 2                                   \n"
+               "2:     b       1b                                      \n"
+               "       .previous                                       \n"
                "       .set    mips0                                   \n"
                : "=&r" (temp), "=m" (*m)
                : "ir" (~(1UL << (nr & SZLONG_MASK))), "m" (*m));
@@ -166,7 +172,10 @@ static inline void change_bit(unsigned long nr, volatile unsigned long *addr)
                "1:     " __LL "%0, %1          # change_bit    \n"
                "       xor     %0, %2                          \n"
                "       " __SC  "%0, %1                         \n"
-               "       beqz    %0, 1b                          \n"
+               "       beqz    %0, 2f                          \n"
+               "       .subsection 2                           \n"
+               "2:     b       1b                              \n"
+               "       .previous                               \n"
                "       .set    mips0                           \n"
                : "=&r" (temp), "=m" (*m)
                : "ir" (1UL << (nr & SZLONG_MASK)), "m" (*m));
@@ -222,8 +231,12 @@ static inline int test_and_set_bit(unsigned long nr,
                "1:     " __LL "%0, %1          # test_and_set_bit      \n"
                "       or      %2, %0, %3                              \n"
                "       " __SC  "%2, %1                                 \n"
-               "       beqz    %2, 1b                                  \n"
+               "       beqz    %2, 2f                                  \n"
                "        and    %2, %0, %3                              \n"
+               "       .subsection 2                                   \n"
+               "2:     b       1b                                      \n"
+               "        nop                                            \n"
+               "       .previous                                       \n"
                "       .set    pop                                     \n"
                : "=&r" (temp), "=m" (*m), "=&r" (res)
                : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@@ -290,8 +303,12 @@ static inline int test_and_clear_bit(unsigned long nr,
                "       or      %2, %0, %3                              \n"
                "       xor     %2, %3                                  \n"
                "       " __SC  "%2, %1                                 \n"
-               "       beqz    %2, 1b                                  \n"
+               "       beqz    %2, 2f                                  \n"
                "        and    %2, %0, %3                              \n"
+               "       .subsection 2                                   \n"
+               "2:     b       1b                                      \n"
+               "        nop                                            \n"
+               "       .previous                                       \n"
                "       .set    pop                                     \n"
                : "=&r" (temp), "=m" (*m), "=&r" (res)
                : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)
@@ -356,8 +373,12 @@ static inline int test_and_change_bit(unsigned long nr,
                "1:     " __LL  "%0, %1         # test_and_change_bit   \n"
                "       xor     %2, %0, %3                              \n"
                "       " __SC  "\t%2, %1                               \n"
-               "       beqz    %2, 1b                                  \n"
+               "       beqz    %2, 2f                                  \n"
                "        and    %2, %0, %3                              \n"
+               "       .subsection 2                                   \n"
+               "2:     b       1b                                      \n"
+               "        nop                                            \n"
+               "       .previous                                       \n"
                "       .set    pop                                     \n"
                : "=&r" (temp), "=m" (*m), "=&r" (res)
                : "r" (1UL << (nr & SZLONG_MASK)), "m" (*m)