[Sound-open-firmware] [PATCH] core: atomic: Add atomic addition and subtraction APIs

[Liam Girdwood]

Add APIs to allow atomic additions or subtractions.

This API can be used to synchronize buffer W/R pointers between
pipelines and components running on different DSP cores.

Signed-off-by: Liam Girdwood <liam.r.girdwood at linux.intel.com>
---
 src/arch/xtensa/include/arch/Makefile.am |  1 +
 src/arch/xtensa/include/arch/atomic.h    | 77 ++++++++++++++++++++++++++++++++
 src/include/reef/Makefile.am             |  1 +
 src/include/reef/atomic.h                | 53 ++++++++++++++++++++++
 4 files changed, 132 insertions(+)
 create mode 100644 src/arch/xtensa/include/arch/atomic.h
 create mode 100644 src/include/reef/atomic.h

diff --git a/src/arch/xtensa/include/arch/Makefile.am b/src/arch/xtensa/include/arch/Makefile.am
index 42b3b700..135ef64c 100644
--- a/src/arch/xtensa/include/arch/Makefile.am
+++ b/src/arch/xtensa/include/arch/Makefile.am
@@ -1,4 +1,5 @@
 noinst_HEADERS = \
+	atomic.h \
 	cache.h \
 	interrupt.h \
 	reef.h \
diff --git a/src/arch/xtensa/include/arch/atomic.h b/src/arch/xtensa/include/arch/atomic.h
new file mode 100644
index 00000000..80c4522f
--- /dev/null
+++ b/src/arch/xtensa/include/arch/atomic.h
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2018, Intel Corporation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of the Intel Corporation nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Liam Girdwood <liam.r.girdwood at linux.intel.com>
+ *
+ */
+
+#ifndef __ARCH_ATOMIC_H_
+#define __ARCH_ATOMIC_H_
+
+#include <stdint.h>
+#include <errno.h>
+
+typedef struct {
+	volatile int32_t value;
+} atomic_t;
+
+static inline void arch_atomic_init(atomic_t *a, int32_t value)
+{
+	a->value = value;
+}
+
+static inline void arch_atomic_add(atomic_t *a, int32_t value)
+{
+	int32_t result, current;
+
+	__asm__ __volatile__(
+		"1:     l32i    %1, %2, 0\n"
+		"       wsr     %1, scompare1\n"
+		"       add     %0, %1, %3\n"
+		"       s32c1i  %0, %2, 0\n"
+		"       bne     %0, %1, 1b\n"
+		: "=&a" (result), "=&a" (current)
+		: "a" (&a->value), "a" (value)
+		: "memory");
+}
+
+static inline void arch_atomic_sub(atomic_t *a, int32_t value)
+{
+	int32_t result, current;
+
+	__asm__ __volatile__(
+		"1:     l32i    %1, %2, 0\n"
+		"       wsr     %1, scompare1\n"
+		"       sub     %0, %1, %3\n"
+		"       s32c1i  %0, %2, 0\n"
+		"       bne     %0, %1, 1b\n"
+		: "=&a" (result), "=&a" (current)
+		: "a" (&a->value), "a" (value)
+		: "memory");
+}
+
+#endif
diff --git a/src/include/reef/Makefile.am b/src/include/reef/Makefile.am
index 8b47664d..f6f9bb29 100644
--- a/src/include/reef/Makefile.am
+++ b/src/include/reef/Makefile.am
@@ -7,6 +7,7 @@ includedir = $(prefix)/include/sof/reef
 
 include_HEADERS = \
 	alloc.h \
+	atomic.h \
 	clock.h \
 	dai.h \
 	debug.h \
diff --git a/src/include/reef/atomic.h b/src/include/reef/atomic.h
new file mode 100644
index 00000000..b26b7016
--- /dev/null
+++ b/src/include/reef/atomic.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2018, Intel Corporation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *   * Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of the Intel Corporation nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Author: Liam Girdwood <liam.r.girdwood at linux.intel.com>
+ *
+ */
+
+#ifndef __INCLUDE_ATOMIC_H_
+#define __INCLUDE_ATOMIC_H_
+
+#include <stdint.h>
+#include <arch/atomic.h>
+
+static inline void atomic_init(atomic_t *a, int32_t value)
+{
+	arch_atomic_init(a, value);
+}
+
+static inline void atomic_add(atomic_t *a, int32_t value)
+{
+	arch_atomic_add(a, value);
+}
+
+static inline void atomic_sub(atomic_t *a, int32_t value)
+{
+	arch_atomic_sub(a, value);
+}
+
+#endif
-- 
2.14.1