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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /arch/sh/include/asm/atomic-llsc.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/sh/include/asm/atomic-llsc.h')
-rw-r--r--arch/sh/include/asm/atomic-llsc.h88
1 files changed, 88 insertions, 0 deletions
diff --git a/arch/sh/include/asm/atomic-llsc.h b/arch/sh/include/asm/atomic-llsc.h
new file mode 100644
index 000000000..b63dcfbfa
--- /dev/null
+++ b/arch/sh/include/asm/atomic-llsc.h
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 arch_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 arch_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_FETCH_OP(op) \
+static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ unsigned long res, temp; \
+ \
+ __asm__ __volatile__ ( \
+"1: movli.l @%3, %0 ! atomic_fetch_" #op " \n" \
+" mov %0, %1 \n" \
+" " #op " %2, %0 \n" \
+" movco.l %0, @%3 \n" \
+" bf 1b \n" \
+" synco \n" \
+ : "=&z" (temp), "=&r" (res) \
+ : "r" (i), "r" (&v->counter) \
+ : "t"); \
+ \
+ return res; \
+}
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_OP_RETURN(op) ATOMIC_FETCH_OP(op)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
+
+ATOMIC_OPS(and)
+ATOMIC_OPS(or)
+ATOMIC_OPS(xor)
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#endif /* __ASM_SH_ATOMIC_LLSC_H */