sh: Provide movli.l/movco.l-based cmpxchg.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 71 insertions, 0 deletions

diff --git a/arch/sh/include/asm/cmpxchg-llsc.h b/arch/sh/include/asm/cmpxchg-llsc.h
new file mode 100644
index 000000000000..aee3bf286581
--- /dev/null
+++ b/arch/sh/include/asm/cmpxchg-llsc.h
@@ -0,0 +1,71 @@
+#ifndef __ASM_SH_CMPXCHG_LLSC_H
+#define __ASM_SH_CMPXCHG_LLSC_H
+
+static inline unsigned long xchg_u32(volatile u32 *m, unsigned long val)
+{
+        unsigned long retval;
+        unsigned long tmp;
+
+        __asm__ __volatile__ (
+                "1:                                     \n\t"
+                "movli.l        @%1, %0 ! xchg_u32      \n\t"
+                "mov            %0, %2                  \n\t"
+                "mov            %4, %0                  \n\t"
+                "movco.l        %0, @%1                 \n\t"
+                "bf             1b                      \n\t"
+                "synco                                  \n\t"
+                : "=&z"(tmp), "=r" (m), "=&r" (retval)
+                : "1" (m), "r" (val)
+                : "t", "memory"
+        );
+
+        return retval;
+}
+
+static inline unsigned long xchg_u8(volatile u8 *m, unsigned long val)
+{
+        unsigned long retval;
+        unsigned long tmp;
+
+        __asm__ __volatile__ (
+                "1:                                     \n\t"
+                "movli.l        @%1, %0 ! xchg_u8       \n\t"
+                "mov            %0, %2                  \n\t"
+                "mov            %4, %0                  \n\t"
+                "movco.l        %0, @%1                 \n\t"
+                "bf             1b                      \n\t"
+                "synco                                  \n\t"
+                : "=&z"(tmp), "=r" (m), "=&r" (retval)
+                : "1" (m), "r" (val & 0xff)
+                : "t", "memory"
+        );
+
+        return retval;
+}
+
+static inline unsigned long
+__cmpxchg_u32(volatile int *m, unsigned long old, unsigned long new)
+{
+        unsigned long retval;
+        unsigned long tmp;
+
+        __asm__ __volatile__ (
+                "1:                                             \n\t"
+                "movli.l        @%1, %0 ! __cmpxchg_u32         \n\t"
+                "mov            %0, %2                          \n\t"
+                "cmp/eq         %2, %4                          \n\t"
+                "bf             2f                              \n\t"
+                "mov            %5, %0                          \n\t"
+                "2:                                             \n\t"
+                "movco.l        %0, @%1                         \n\t"
+                "bf             1b                              \n\t"
+                "synco                                          \n\t"
+                : "=&z" (tmp), "=r" (m), "=&r" (retval)
+                : "1" (m), "r" (old), "r" (new)
+                : "t", "memory"
+        );
+
+        return retval;
+}
+
+#endif /* __ASM_SH_CMPXCHG_LLSC_H */