Merge branch 'libbpf/xsk cleanups'

Björn Töpel says:

====================

This series removes a header dependency from xsk.h, and moves
libbpf_util.h into xsk.h.

More details in each commit!

Thank you,
Björn
====================

Signed-off-by: Andrii Nakryiko <[email protected]>

tools/lib/bpf/Makefile

@@ -228,7 +228,6 @@ install_headers: $(BPF_HELPER_DEFS)
 		$(call do_install,bpf.h,$(prefix)/include/bpf,644); \
 		$(call do_install,libbpf.h,$(prefix)/include/bpf,644); \
 		$(call do_install,btf.h,$(prefix)/include/bpf,644); \
-		$(call do_install,libbpf_util.h,$(prefix)/include/bpf,644); \
 		$(call do_install,libbpf_common.h,$(prefix)/include/bpf,644); \
 		$(call do_install,xsk.h,$(prefix)/include/bpf,644); \
 		$(call do_install,bpf_helpers.h,$(prefix)/include/bpf,644); \

tools/lib/bpf/xsk.h

@@ -3,7 +3,8 @@
 /*
  * AF_XDP user-space access library.
  *
- * Copyright(c) 2018 - 2019 Intel Corporation.
+ * Copyright (c) 2018 - 2019 Intel Corporation.
+ * Copyright (c) 2019 Facebook
  *
  * Author(s): Magnus Karlsson <[email protected]>
  */
@@ -13,15 +14,80 @@
 
 #include <stdio.h>
 #include <stdint.h>
+#include <stdbool.h>
 #include <linux/if_xdp.h>
 
 #include "libbpf.h"
-#include "libbpf_util.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+/* Load-Acquire Store-Release barriers used by the XDP socket
+ * library. The following macros should *NOT* be considered part of
+ * the xsk.h API, and is subject to change anytime.
+ *
+ * LIBRARY INTERNAL
+ */
+
+#define __XSK_READ_ONCE(x) (*(volatile typeof(x) *)&x)
+#define __XSK_WRITE_ONCE(x, v) (*(volatile typeof(x) *)&x) = (v)
+
+#if defined(__i386__) || defined(__x86_64__)
+# define libbpf_smp_store_release(p, v)					\
+	do {								\
+		asm volatile("" : : : "memory");			\
+		__XSK_WRITE_ONCE(*p, v);				\
+	} while (0)
+# define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1 = __XSK_READ_ONCE(*p);			\
+		asm volatile("" : : : "memory");			\
+		___p1;							\
+	})
+#elif defined(__aarch64__)
+# define libbpf_smp_store_release(p, v)					\
+		asm volatile ("stlr %w1, %0" : "=Q" (*p) : "r" (v) : "memory")
+# define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1;					\
+		asm volatile ("ldar %w0, %1"				\
+			      : "=r" (___p1) : "Q" (*p) : "memory");	\
+		___p1;							\
+	})
+#elif defined(__riscv)
+# define libbpf_smp_store_release(p, v)					\
+	do {								\
+		asm volatile ("fence rw,w" : : : "memory");		\
+		__XSK_WRITE_ONCE(*p, v);				\
+	} while (0)
+# define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1 = __XSK_READ_ONCE(*p);			\
+		asm volatile ("fence r,rw" : : : "memory");		\
+		___p1;							\
+	})
+#endif
+
+#ifndef libbpf_smp_store_release
+#define libbpf_smp_store_release(p, v)					\
+	do {								\
+		__sync_synchronize();					\
+		__XSK_WRITE_ONCE(*p, v);				\
+	} while (0)
+#endif
+
+#ifndef libbpf_smp_load_acquire
+#define libbpf_smp_load_acquire(p)					\
+	({								\
+		typeof(*p) ___p1 = __XSK_READ_ONCE(*p);			\
+		__sync_synchronize();					\
+		___p1;							\
+	})
+#endif
+
+/* LIBRARY INTERNAL -- END */
+
 /* Do not access these members directly. Use the functions below. */
 #define DEFINE_XSK_RING(name) \
 struct name { \