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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-11 08:27:49 +0000
commitace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch)
treeb2d64bc10158fdd5497876388cd68142ca374ed3 /arch/xtensa/include/asm/atomic.h
parentInitial commit. (diff)
downloadlinux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz
linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/xtensa/include/asm/atomic.h')
-rw-r--r--arch/xtensa/include/asm/atomic.h269
1 files changed, 269 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/atomic.h b/arch/xtensa/include/asm/atomic.h
new file mode 100644
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+++ b/arch/xtensa/include/asm/atomic.h
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+/*
+ * include/asm-xtensa/atomic.h
+ *
+ * Atomic operations that C can't guarantee us. Useful for resource counting..
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2008 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_ATOMIC_H
+#define _XTENSA_ATOMIC_H
+
+#include <linux/stringify.h>
+#include <linux/types.h>
+#include <asm/processor.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+/*
+ * This Xtensa implementation assumes that the right mechanism
+ * for exclusion is for locking interrupts to level EXCM_LEVEL.
+ *
+ * Locking interrupts looks like this:
+ *
+ * rsil a14, TOPLEVEL
+ * <code>
+ * wsr a14, PS
+ * rsync
+ *
+ * Note that a14 is used here because the register allocation
+ * done by the compiler is not guaranteed and a window overflow
+ * may not occur between the rsil and wsr instructions. By using
+ * a14 in the rsil, the machine is guaranteed to be in a state
+ * where no register reference will cause an overflow.
+ */
+
+/**
+ * atomic_read - read atomic variable
+ * @v: pointer of type atomic_t
+ *
+ * Atomically reads the value of @v.
+ */
+#define arch_atomic_read(v) READ_ONCE((v)->counter)
+
+/**
+ * atomic_set - set atomic variable
+ * @v: pointer of type atomic_t
+ * @i: required value
+ *
+ * Atomically sets the value of @v to @i.
+ */
+#define arch_atomic_set(v,i) WRITE_ONCE((v)->counter, (i))
+
+#if XCHAL_HAVE_EXCLUSIVE
+#define ATOMIC_OP(op) \
+static inline void arch_atomic_##op(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32ex %[tmp], %[addr]\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ " s32ex %[result], %[addr]\n" \
+ " getex %[result]\n" \
+ " beqz %[result], 1b\n" \
+ : [result] "=&a" (result), [tmp] "=&a" (tmp) \
+ : [i] "a" (i), [addr] "a" (v) \
+ : "memory" \
+ ); \
+} \
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int arch_atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32ex %[tmp], %[addr]\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ " s32ex %[result], %[addr]\n" \
+ " getex %[result]\n" \
+ " beqz %[result], 1b\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ : [result] "=&a" (result), [tmp] "=&a" (tmp) \
+ : [i] "a" (i), [addr] "a" (v) \
+ : "memory" \
+ ); \
+ \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(op) \
+static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32ex %[tmp], %[addr]\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ " s32ex %[result], %[addr]\n" \
+ " getex %[result]\n" \
+ " beqz %[result], 1b\n" \
+ : [result] "=&a" (result), [tmp] "=&a" (tmp) \
+ : [i] "a" (i), [addr] "a" (v) \
+ : "memory" \
+ ); \
+ \
+ return tmp; \
+}
+
+#elif XCHAL_HAVE_S32C1I
+#define ATOMIC_OP(op) \
+static inline void arch_atomic_##op(int i, atomic_t * v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32i %[tmp], %[mem]\n" \
+ " wsr %[tmp], scompare1\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ " s32c1i %[result], %[mem]\n" \
+ " bne %[result], %[tmp], 1b\n" \
+ : [result] "=&a" (result), [tmp] "=&a" (tmp), \
+ [mem] "+m" (*v) \
+ : [i] "a" (i) \
+ : "memory" \
+ ); \
+} \
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int arch_atomic_##op##_return(int i, atomic_t * v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32i %[tmp], %[mem]\n" \
+ " wsr %[tmp], scompare1\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ " s32c1i %[result], %[mem]\n" \
+ " bne %[result], %[tmp], 1b\n" \
+ " " #op " %[result], %[result], %[i]\n" \
+ : [result] "=&a" (result), [tmp] "=&a" (tmp), \
+ [mem] "+m" (*v) \
+ : [i] "a" (i) \
+ : "memory" \
+ ); \
+ \
+ return result; \
+}
+
+#define ATOMIC_FETCH_OP(op) \
+static inline int arch_atomic_fetch_##op(int i, atomic_t * v) \
+{ \
+ unsigned long tmp; \
+ int result; \
+ \
+ __asm__ __volatile__( \
+ "1: l32i %[tmp], %[mem]\n" \
+ " wsr %[tmp], scompare1\n" \
+ " " #op " %[result], %[tmp], %[i]\n" \
+ " s32c1i %[result], %[mem]\n" \
+ " bne %[result], %[tmp], 1b\n" \
+ : [result] "=&a" (result), [tmp] "=&a" (tmp), \
+ [mem] "+m" (*v) \
+ : [i] "a" (i) \
+ : "memory" \
+ ); \
+ \
+ return result; \
+}
+
+#else /* XCHAL_HAVE_S32C1I */
+
+#define ATOMIC_OP(op) \
+static inline void arch_atomic_##op(int i, atomic_t * v) \
+{ \
+ unsigned int vval; \
+ \
+ __asm__ __volatile__( \
+ " rsil a14, "__stringify(TOPLEVEL)"\n" \
+ " l32i %[result], %[mem]\n" \
+ " " #op " %[result], %[result], %[i]\n" \
+ " s32i %[result], %[mem]\n" \
+ " wsr a14, ps\n" \
+ " rsync\n" \
+ : [result] "=&a" (vval), [mem] "+m" (*v) \
+ : [i] "a" (i) \
+ : "a14", "memory" \
+ ); \
+} \
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int arch_atomic_##op##_return(int i, atomic_t * v) \
+{ \
+ unsigned int vval; \
+ \
+ __asm__ __volatile__( \
+ " rsil a14,"__stringify(TOPLEVEL)"\n" \
+ " l32i %[result], %[mem]\n" \
+ " " #op " %[result], %[result], %[i]\n" \
+ " s32i %[result], %[mem]\n" \
+ " wsr a14, ps\n" \
+ " rsync\n" \
+ : [result] "=&a" (vval), [mem] "+m" (*v) \
+ : [i] "a" (i) \
+ : "a14", "memory" \
+ ); \
+ \
+ return vval; \
+}
+
+#define ATOMIC_FETCH_OP(op) \
+static inline int arch_atomic_fetch_##op(int i, atomic_t * v) \
+{ \
+ unsigned int tmp, vval; \
+ \
+ __asm__ __volatile__( \
+ " rsil a14,"__stringify(TOPLEVEL)"\n" \
+ " l32i %[result], %[mem]\n" \
+ " " #op " %[tmp], %[result], %[i]\n" \
+ " s32i %[tmp], %[mem]\n" \
+ " wsr a14, ps\n" \
+ " rsync\n" \
+ : [result] "=&a" (vval), [tmp] "=&a" (tmp), \
+ [mem] "+m" (*v) \
+ : [i] "a" (i) \
+ : "a14", "memory" \
+ ); \
+ \
+ return vval; \
+}
+
+#endif /* XCHAL_HAVE_S32C1I */
+
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op) ATOMIC_OP_RETURN(op)
+
+ATOMIC_OPS(add)
+ATOMIC_OPS(sub)
+
+#define arch_atomic_add_return arch_atomic_add_return
+#define arch_atomic_sub_return arch_atomic_sub_return
+#define arch_atomic_fetch_add arch_atomic_fetch_add
+#define arch_atomic_fetch_sub arch_atomic_fetch_sub
+
+#undef ATOMIC_OPS
+#define ATOMIC_OPS(op) ATOMIC_OP(op) ATOMIC_FETCH_OP(op)
+
+ATOMIC_OPS(and)
+ATOMIC_OPS(or)
+ATOMIC_OPS(xor)
+
+#define arch_atomic_fetch_and arch_atomic_fetch_and
+#define arch_atomic_fetch_or arch_atomic_fetch_or
+#define arch_atomic_fetch_xor arch_atomic_fetch_xor
+
+#undef ATOMIC_OPS
+#undef ATOMIC_FETCH_OP
+#undef ATOMIC_OP_RETURN
+#undef ATOMIC_OP
+
+#endif /* _XTENSA_ATOMIC_H */