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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/hexagon/include/asm/atomic.h
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/hexagon/include/asm/atomic.h')
-rw-r--r--arch/hexagon/include/asm/atomic.h185
1 files changed, 185 insertions, 0 deletions
diff --git a/arch/hexagon/include/asm/atomic.h b/arch/hexagon/include/asm/atomic.h
new file mode 100644
index 000000000..6e94f8d04
--- /dev/null
+++ b/arch/hexagon/include/asm/atomic.h
@@ -0,0 +1,185 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Atomic operations for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
+ */
+
+#ifndef _ASM_ATOMIC_H
+#define _ASM_ATOMIC_H
+
+#include <linux/types.h>
+#include <asm/cmpxchg.h>
+#include <asm/barrier.h>
+
+/* Normal writes in our arch don't clear lock reservations */
+
+static inline void arch_atomic_set(atomic_t *v, int new)
+{
+ asm volatile(
+ "1: r6 = memw_locked(%0);\n"
+ " memw_locked(%0,p0) = %1;\n"
+ " if (!P0) jump 1b;\n"
+ :
+ : "r" (&v->counter), "r" (new)
+ : "memory", "p0", "r6"
+ );
+}
+
+#define arch_atomic_set_release(v, i) arch_atomic_set((v), (i))
+
+/**
+ * arch_atomic_read - reads a word, atomically
+ * @v: pointer to atomic value
+ *
+ * Assumes all word reads on our architecture are atomic.
+ */
+#define arch_atomic_read(v) READ_ONCE((v)->counter)
+
+/**
+ * arch_atomic_xchg - atomic
+ * @v: pointer to memory to change
+ * @new: new value (technically passed in a register -- see xchg)
+ */
+#define arch_atomic_xchg(v, new) (arch_xchg(&((v)->counter), (new)))
+
+
+/**
+ * arch_atomic_cmpxchg - atomic compare-and-exchange values
+ * @v: pointer to value to change
+ * @old: desired old value to match
+ * @new: new value to put in
+ *
+ * Parameters are then pointer, value-in-register, value-in-register,
+ * and the output is the old value.
+ *
+ * Apparently this is complicated for archs that don't support
+ * the memw_locked like we do (or it's broken or whatever).
+ *
+ * Kind of the lynchpin of the rest of the generically defined routines.
+ * Remember V2 had that bug with dotnew predicate set by memw_locked.
+ *
+ * "old" is "expected" old val, __oldval is actual old value
+ */
+static inline int arch_atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+ int __oldval;
+
+ asm volatile(
+ "1: %0 = memw_locked(%1);\n"
+ " { P0 = cmp.eq(%0,%2);\n"
+ " if (!P0.new) jump:nt 2f; }\n"
+ " memw_locked(%1,P0) = %3;\n"
+ " if (!P0) jump 1b;\n"
+ "2:\n"
+ : "=&r" (__oldval)
+ : "r" (&v->counter), "r" (old), "r" (new)
+ : "memory", "p0"
+ );
+
+ return __oldval;
+}
+
+#define ATOMIC_OP(op) \
+static inline void arch_atomic_##op(int i, atomic_t *v) \
+{ \
+ int output; \
+ \
+ __asm__ __volatile__ ( \
+ "1: %0 = memw_locked(%1);\n" \
+ " %0 = "#op "(%0,%2);\n" \
+ " memw_locked(%1,P3)=%0;\n" \
+ " if (!P3) jump 1b;\n" \
+ : "=&r" (output) \
+ : "r" (&v->counter), "r" (i) \
+ : "memory", "p3" \
+ ); \
+} \
+
+#define ATOMIC_OP_RETURN(op) \
+static inline int arch_atomic_##op##_return(int i, atomic_t *v) \
+{ \
+ int output; \
+ \
+ __asm__ __volatile__ ( \
+ "1: %0 = memw_locked(%1);\n" \
+ " %0 = "#op "(%0,%2);\n" \
+ " memw_locked(%1,P3)=%0;\n" \
+ " if (!P3) jump 1b;\n" \
+ : "=&r" (output) \
+ : "r" (&v->counter), "r" (i) \
+ : "memory", "p3" \
+ ); \
+ return output; \
+}
+
+#define ATOMIC_FETCH_OP(op) \
+static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \
+{ \
+ int output, val; \
+ \
+ __asm__ __volatile__ ( \
+ "1: %0 = memw_locked(%2);\n" \
+ " %1 = "#op "(%0,%3);\n" \
+ " memw_locked(%2,P3)=%1;\n" \
+ " if (!P3) jump 1b;\n" \
+ : "=&r" (output), "=&r" (val) \
+ : "r" (&v->counter), "r" (i) \
+ : "memory", "p3" \
+ ); \
+ return output; \
+}
+
+#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
+
+/**
+ * arch_atomic_fetch_add_unless - add unless the number is a given value
+ * @v: pointer to value
+ * @a: amount to add
+ * @u: unless value is equal to u
+ *
+ * Returns old value.
+ *
+ */
+
+static inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
+{
+ int __oldval;
+ register int tmp;
+
+ asm volatile(
+ "1: %0 = memw_locked(%2);"
+ " {"
+ " p3 = cmp.eq(%0, %4);"
+ " if (p3.new) jump:nt 2f;"
+ " %1 = add(%0, %3);"
+ " }"
+ " memw_locked(%2, p3) = %1;"
+ " {"
+ " if (!p3) jump 1b;"
+ " }"
+ "2:"
+ : "=&r" (__oldval), "=&r" (tmp)
+ : "r" (v), "r" (a), "r" (u)
+ : "memory", "p3"
+ );
+ return __oldval;
+}
+#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless
+
+#endif