linux/arch/arm64/include/asm/vdso/compat_barrier.h
Vincenzo Frascino a7f71a2c89 arm64: compat: Add vDSO
Provide the arm64 compat (AArch32) vDSO in kernel/vdso32 in a similar
way to what happens in kernel/vdso.

The compat vDSO leverages on an adaptation of the arm architecture code
with few changes:

 - Use of lib/vdso for gettimeofday
 - Implement a syscall based fallback
 - Introduce clock_getres() for the compat library
 - Implement trampolines
 - Implement elf note

To build the compat vDSO a 32 bit compiler is required and needs to be
specified via CONFIG_CROSS_COMPILE_COMPAT_VDSO.

The code is not yet enabled as other prerequisites are missing.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shijith Thotton <sthotton@marvell.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Huw Davies <huw@codeweavers.com>
Link: https://lkml.kernel.org/r/20190621095252.32307-11-vincenzo.frascino@arm.com
2019-06-22 21:21:08 +02:00

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1.1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2018 ARM Limited
*/
#ifndef __COMPAT_BARRIER_H
#define __COMPAT_BARRIER_H
#ifndef __ASSEMBLY__
/*
* Warning: This code is meant to be used with
* ENABLE_COMPAT_VDSO only.
*/
#ifndef ENABLE_COMPAT_VDSO
#error This header is meant to be used with ENABLE_COMPAT_VDSO only
#endif
#ifdef dmb
#undef dmb
#endif
#if __LINUX_ARM_ARCH__ >= 7
#define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory")
#elif __LINUX_ARM_ARCH__ == 6
#define dmb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
: : "r" (0) : "memory")
#else
#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
#endif
#if __LINUX_ARM_ARCH__ >= 8
#define aarch32_smp_mb() dmb(ish)
#define aarch32_smp_rmb() dmb(ishld)
#define aarch32_smp_wmb() dmb(ishst)
#else
#define aarch32_smp_mb() dmb(ish)
#define aarch32_smp_rmb() aarch32_smp_mb()
#define aarch32_smp_wmb() dmb(ishst)
#endif
#undef smp_mb
#undef smp_rmb
#undef smp_wmb
#define smp_mb() aarch32_smp_mb()
#define smp_rmb() aarch32_smp_rmb()
#define smp_wmb() aarch32_smp_wmb()
#endif /* !__ASSEMBLY__ */
#endif /* __COMPAT_BARRIER_H */