linux_dsm_epyc7002/arch/arm/include/asm/barrier.h
Russell King 1d4238c56f ARM: spectre-v1: add array_index_mask_nospec() implementation
Add an implementation of the array_index_mask_nospec() function for
mitigating Spectre variant 1 throughout the kernel.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
2018-05-31 23:27:21 +01:00

102 lines
2.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H
#ifndef __ASSEMBLY__
#define nop() __asm__ __volatile__("mov\tr0,r0\t@ nop\n\t");
#if __LINUX_ARM_ARCH__ >= 7 || \
(__LINUX_ARM_ARCH__ == 6 && defined(CONFIG_CPU_32v6K))
#define sev() __asm__ __volatile__ ("sev" : : : "memory")
#define wfe() __asm__ __volatile__ ("wfe" : : : "memory")
#define wfi() __asm__ __volatile__ ("wfi" : : : "memory")
#endif
#if __LINUX_ARM_ARCH__ >= 7
#define isb(option) __asm__ __volatile__ ("isb " #option : : : "memory")
#define dsb(option) __asm__ __volatile__ ("dsb " #option : : : "memory")
#define dmb(option) __asm__ __volatile__ ("dmb " #option : : : "memory")
#ifdef CONFIG_THUMB2_KERNEL
#define CSDB ".inst.w 0xf3af8014"
#else
#define CSDB ".inst 0xe320f014"
#endif
#define csdb() __asm__ __volatile__(CSDB : : : "memory")
#elif defined(CONFIG_CPU_XSC3) || __LINUX_ARM_ARCH__ == 6
#define isb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
: : "r" (0) : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 5" \
: : "r" (0) : "memory")
#elif defined(CONFIG_CPU_FA526)
#define isb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c5, 4" \
: : "r" (0) : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
#else
#define isb(x) __asm__ __volatile__ ("" : : : "memory")
#define dsb(x) __asm__ __volatile__ ("mcr p15, 0, %0, c7, c10, 4" \
: : "r" (0) : "memory")
#define dmb(x) __asm__ __volatile__ ("" : : : "memory")
#endif
#ifndef CSDB
#define CSDB
#endif
#ifndef csdb
#define csdb()
#endif
#ifdef CONFIG_ARM_HEAVY_MB
extern void (*soc_mb)(void);
extern void arm_heavy_mb(void);
#define __arm_heavy_mb(x...) do { dsb(x); arm_heavy_mb(); } while (0)
#else
#define __arm_heavy_mb(x...) dsb(x)
#endif
#if defined(CONFIG_ARM_DMA_MEM_BUFFERABLE) || defined(CONFIG_SMP)
#define mb() __arm_heavy_mb()
#define rmb() dsb()
#define wmb() __arm_heavy_mb(st)
#define dma_rmb() dmb(osh)
#define dma_wmb() dmb(oshst)
#else
#define mb() barrier()
#define rmb() barrier()
#define wmb() barrier()
#define dma_rmb() barrier()
#define dma_wmb() barrier()
#endif
#define __smp_mb() dmb(ish)
#define __smp_rmb() __smp_mb()
#define __smp_wmb() dmb(ishst)
#ifdef CONFIG_CPU_SPECTRE
static inline unsigned long array_index_mask_nospec(unsigned long idx,
unsigned long sz)
{
unsigned long mask;
asm volatile(
"cmp %1, %2\n"
" sbc %0, %1, %1\n"
CSDB
: "=r" (mask)
: "r" (idx), "Ir" (sz)
: "cc");
return mask;
}
#define array_index_mask_nospec array_index_mask_nospec
#endif
#include <asm-generic/barrier.h>
#endif /* !__ASSEMBLY__ */
#endif /* __ASM_BARRIER_H */