linux-stable/tools/arch/ia64/include/asm/barrier.h
John Paul Adrian Glaubitz f4bf09dc3a ia64: tools: remove duplicate definition of ia64_mf() on ia64
The ia64_mf() macro defined in tools/arch/ia64/include/asm/barrier.h is
already defined in <asm/gcc_intrin.h> on ia64 which causes libbpf
failing to build:

    CC       /usr/src/linux/tools/bpf/bpftool//libbpf/staticobjs/libbpf.o
  In file included from /usr/src/linux/tools/include/asm/barrier.h:24,
                   from /usr/src/linux/tools/include/linux/ring_buffer.h:4,
                   from libbpf.c:37:
  /usr/src/linux/tools/include/asm/../../arch/ia64/include/asm/barrier.h:43: error: "ia64_mf" redefined [-Werror]
     43 | #define ia64_mf()       asm volatile ("mf" ::: "memory")
        |
  In file included from /usr/include/ia64-linux-gnu/asm/intrinsics.h:20,
                   from /usr/include/ia64-linux-gnu/asm/swab.h:11,
                   from /usr/include/linux/swab.h:8,
                   from /usr/include/linux/byteorder/little_endian.h:13,
                   from /usr/include/ia64-linux-gnu/asm/byteorder.h:5,
                   from /usr/src/linux/tools/include/uapi/linux/perf_event.h:20,
                   from libbpf.c:36:
  /usr/include/ia64-linux-gnu/asm/gcc_intrin.h:382: note: this is the location of the previous definition
    382 | #define ia64_mf() __asm__ volatile ("mf" ::: "memory")
        |
  cc1: all warnings being treated as errors

Thus, remove the definition from tools/arch/ia64/include/asm/barrier.h.

Signed-off-by: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-04-16 16:10:37 -07:00

59 lines
1.9 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copied from the kernel sources to tools/:
*
* Memory barrier definitions. This is based on information published
* in the Processor Abstraction Layer and the System Abstraction Layer
* manual.
*
* Copyright (C) 1998-2003 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
* Copyright (C) 1999 Don Dugger <don.dugger@intel.com>
*/
#ifndef _TOOLS_LINUX_ASM_IA64_BARRIER_H
#define _TOOLS_LINUX_ASM_IA64_BARRIER_H
#include <linux/compiler.h>
/*
* Macros to force memory ordering. In these descriptions, "previous"
* and "subsequent" refer to program order; "visible" means that all
* architecturally visible effects of a memory access have occurred
* (at a minimum, this means the memory has been read or written).
*
* wmb(): Guarantees that all preceding stores to memory-
* like regions are visible before any subsequent
* stores and that all following stores will be
* visible only after all previous stores.
* rmb(): Like wmb(), but for reads.
* mb(): wmb()/rmb() combo, i.e., all previous memory
* accesses are visible before all subsequent
* accesses and vice versa. This is also known as
* a "fence."
*
* Note: "mb()" and its variants cannot be used as a fence to order
* accesses to memory mapped I/O registers. For that, mf.a needs to
* be used. However, we don't want to always use mf.a because (a)
* it's (presumably) much slower than mf and (b) mf.a is supported for
* sequential memory pages only.
*/
#define mb() ia64_mf()
#define rmb() mb()
#define wmb() mb()
#define smp_store_release(p, v) \
do { \
barrier(); \
WRITE_ONCE(*p, v); \
} while (0)
#define smp_load_acquire(p) \
({ \
typeof(*p) ___p1 = READ_ONCE(*p); \
barrier(); \
___p1; \
})
#endif /* _TOOLS_LINUX_ASM_IA64_BARRIER_H */