--- /dev/null
+#ifndef _UAPI_LINUX_RSEQ_H
+#define _UAPI_LINUX_RSEQ_H
+
+/*
+ * linux/rseq.h
+ *
+ * Restartable sequences system call API
+ *
+ * Copyright (c) 2015-2016 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#ifdef __KERNEL__
+# include <linux/types.h>
+#else /* #ifdef __KERNEL__ */
+# include <stdint.h>
+#endif /* #else #ifdef __KERNEL__ */
+
+#include <asm/byteorder.h>
+
+#ifdef __LP64__
+# define RSEQ_FIELD_u32_u64(field) uint64_t field
+#elif defined(__BYTE_ORDER) ? \
+ __BYTE_ORDER == __BIG_ENDIAN : defined(__BIG_ENDIAN)
+# define RSEQ_FIELD_u32_u64(field) uint32_t _padding ## field, field
+#else
+# define RSEQ_FIELD_u32_u64(field) uint32_t field, _padding ## field
+#endif
+
+enum rseq_flags {
+ RSEQ_FORCE_UNREGISTER = (1 << 0),
+};
+
+/*
+ * struct rseq_cs is aligned on 4 * 8 bytes to ensure it is always
+ * contained within a single cache-line. It is usually declared as
+ * link-time constant data.
+ */
+struct rseq_cs {
+ RSEQ_FIELD_u32_u64(start_ip);
+ RSEQ_FIELD_u32_u64(post_commit_ip);
+ RSEQ_FIELD_u32_u64(abort_ip);
+} __attribute__((aligned(4 * sizeof(uint64_t))));
+
+union rseq_cpu_event {
+ struct {
+ /*
+ * Restartable sequences cpu_id field.
+ * Updated by the kernel, and read by user-space with
+ * single-copy atomicity semantics. Aligned on 32-bit.
+ * Negative values are reserved for user-space.
+ */
+ int32_t cpu_id;
+ /*
+ * Restartable sequences event_counter field.
+ * Updated by the kernel, and read by user-space with
+ * single-copy atomicity semantics. Aligned on 32-bit.
+ */
+ uint32_t event_counter;
+ } e;
+ /*
+ * On architectures with 64-bit aligned reads, both cpu_id and
+ * event_counter can be read with single-copy atomicity
+ * semantics.
+ */
+ uint64_t v;
+};
+
+/*
+ * struct rseq is aligned on 2 * 8 bytes to ensure it is always
+ * contained within a single cache-line.
+ */
+struct rseq {
+ union rseq_cpu_event u;
+ /*
+ * Restartable sequences rseq_cs field.
+ * Contains NULL when no critical section is active for the
+ * current thread, or holds a pointer to the currently active
+ * struct rseq_cs.
+ * Updated by user-space at the beginning and end of assembly
+ * instruction sequence block, and by the kernel when it
+ * restarts an assembly instruction sequence block. Read by the
+ * kernel with single-copy atomicity semantics. Aligned on
+ * 64-bit.
+ */
+ RSEQ_FIELD_u32_u64(rseq_cs);
+} __attribute__((aligned(2 * sizeof(uint64_t))));
+
+#endif /* _UAPI_LINUX_RSEQ_H */
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