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-rw-r--r--kernel/arch/sh/include/asm/atomic-llsc.h88
1 files changed, 88 insertions, 0 deletions
diff --git a/kernel/arch/sh/include/asm/atomic-llsc.h b/kernel/arch/sh/include/asm/atomic-llsc.h
new file mode 100644
index 000000000..8575dccb9
--- /dev/null
+++ b/kernel/arch/sh/include/asm/atomic-llsc.h
@@ -0,0 +1,88 @@
+#ifndef __ASM_SH_ATOMIC_LLSC_H
+#define __ASM_SH_ATOMIC_LLSC_H
+
+/*
+ * SH-4A note:
+ *
+ * We basically get atomic_xxx_return() for free compared with
+ * atomic_xxx(). movli.l/movco.l require r0 due to the instruction
+ * encoding, so the retval is automatically set without having to
+ * do any special work.
+ */
+/*
+ * To get proper branch prediction for the main line, we must branch
+ * forward to code at the end of this object's .text section, then
+ * branch back to restart the operation.
+ */
+
+#define ATOMIC_OP(op) \
+static inline void atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ \
+ __asm__ __volatile__ ( \
+"1: movli.l @%2, %0 ! atomic_" #op "\n" \
+" " #op " %1, %0 \n" \
+" movco.l %0, @%2 \n" \
+" bf 1b \n" \
+ : "=&z" (tmp) \
+ : "r" (i), "r" (&v->counter) \
+ : "t"); \
+}
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned long temp; \
+ \
+ __asm__ __volatile__ ( \
+"1: movli.l @%2, %0 ! atomic_" #op "_return \n" \
+" " #op " %1, %0 \n" \
+" movco.l %0, @%2 \n" \
+" bf 1b \n" \
+" synco \n" \
+ : "=&z" (temp) \
+ : "r" (i), "r" (&v->counter) \
+ : "t"); \
+ \
+ return temp; \
+}
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__ (
+"1: movli.l @%2, %0 ! atomic_clear_mask \n"
+" and %1, %0 \n"
+" movco.l %0, @%2 \n"
+" bf 1b \n"
+ : "=&z" (tmp)
+ : "r" (~mask), "r" (&v->counter)
+ : "t");
+}
+
+static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+ unsigned long tmp;
+
+ __asm__ __volatile__ (
+"1: movli.l @%2, %0 ! atomic_set_mask \n"
+" or %1, %0 \n"
+" movco.l %0, @%2 \n"
+" bf 1b \n"
+ : "=&z" (tmp)
+ : "r" (mask), "r" (&v->counter)
+ : "t");
+}
+
+#endif /* __ASM_SH_ATOMIC_LLSC_H */