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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Based on arch/arm/include/asm/barrier.h
*
* Copyright (C) 2012 ARM Ltd.
*/
#ifndef __ASM_BARRIER_H
#define __ASM_BARRIER_H
#ifndef __ASSEMBLY__
#include <linux/kasan-checks.h>
#define __nops(n) ".rept " #n "\nnop\n.endr\n"
#define nops(n) asm volatile(__nops(n))
#define sev() asm volatile("sev" : : : "memory")
#define wfe() asm volatile("wfe" : : : "memory")
#define wfi() asm volatile("wfi" : : : "memory")
#define isb() asm volatile("isb" : : : "memory")
#define dmb(opt) asm volatile("dmb " #opt : : : "memory")
#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
#define psb_csync() asm volatile("hint #17" : : : "memory")
#define __tsb_csync() asm volatile("hint #18" : : : "memory")
#define csdb() asm volatile("hint #20" : : : "memory")
/*
* Data Gathering Hint:
* This instruction prevents merging memory accesses with Normal-NC or
* Device-GRE attributes before the hint instruction with any memory accesses
* appearing after the hint instruction.
*/
#define dgh() asm volatile("hint #6" : : : "memory")
#ifdef CONFIG_ARM64_PSEUDO_NMI
#define pmr_sync() \
do { \
extern struct static_key_false gic_pmr_sync; \
\
if (static_branch_unlikely(&gic_pmr_sync)) \
dsb(sy); \
} while(0)
#else
#define pmr_sync() do {} while (0)
#endif
#define mb() dsb(sy)
#define rmb() dsb(ld)
#define wmb() dsb(st)
#define dma_mb() dmb(osh)
#define dma_rmb() dmb(oshld)
#define dma_wmb() dmb(oshst)
#define io_stop_wc() dgh()
#define tsb_csync() \
do { \
/* \
* CPUs affected by Arm Erratum 2054223 or 2067961 needs \
* another TSB to ensure the trace is flushed. The barriers \
* don't have to be strictly back to back, as long as the \
* CPU is in trace prohibited state. \
*/ \
if (cpus_have_final_cap(ARM64_WORKAROUND_TSB_FLUSH_FAILURE)) \
__tsb_csync(); \
__tsb_csync(); \
} while (0)
/*
* Generate a mask for array_index__nospec() that is ~0UL when 0 <= idx < sz
* and 0 otherwise.
*/
#define array_index_mask_nospec array_index_mask_nospec
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, xzr, xzr\n"
: "=r" (mask)
: "r" (idx), "Ir" (sz)
: "cc");
csdb();
return mask;
}
/*
* Ensure that reads of the counter are treated the same as memory reads
* for the purposes of ordering by subsequent memory barriers.
*
* This insanity brought to you by speculative system register reads,
* out-of-order memory accesses, sequence locks and Thomas Gleixner.
*
* https://lore.kernel.org/r/alpine.DEB.2.21.1902081950260.1662@nanos.tec.linutronix.de/
*/
#define arch_counter_enforce_ordering(val) do { \
u64 tmp, _val = (val); \
\
asm volatile( \
" eor %0, %1, %1\n" \
" add %0, sp, %0\n" \
" ldr xzr, [%0]" \
: "=r" (tmp) : "r" (_val)); \
} while (0)
#define __smp_mb() dmb(ish)
#define __smp_rmb() dmb(ishld)
#define __smp_wmb() dmb(ishst)
#define __smp_store_release(p, v) \
do { \
typeof(p) __p = (p); \
union { __unqual_scalar_typeof(*p) __val; char __c[1]; } __u = \
{ .__val = (__force __unqual_scalar_typeof(*p)) (v) }; \
compiletime_assert_atomic_type(*p); \
kasan_check_write(__p, sizeof(*p)); \
switch (sizeof(*p)) { \
case 1: \
asm volatile ("stlrb %w1, %0" \
: "=Q" (*__p) \
: "r" (*(__u8 *)__u.__c) \
: "memory"); \
break; \
case 2: \
asm volatile ("stlrh %w1, %0" \
: "=Q" (*__p) \
: "r" (*(__u16 *)__u.__c) \
: "memory"); \
break; \
case 4: \
asm volatile ("stlr %w1, %0" \
: "=Q" (*__p) \
: "r" (*(__u32 *)__u.__c) \
: "memory"); \
break; \
case 8: \
asm volatile ("stlr %1, %0" \
: "=Q" (*__p) \
: "r" (*(__u64 *)__u.__c) \
: "memory"); \
break; \
} \
} while (0)
#define __smp_load_acquire(p) \
({ \
union { __unqual_scalar_typeof(*p) __val; char __c[1]; } __u; \
typeof(p) __p = (p); \
compiletime_assert_atomic_type(*p); \
kasan_check_read(__p, sizeof(*p)); \
switch (sizeof(*p)) { \
case 1: \
asm volatile ("ldarb %w0, %1" \
: "=r" (*(__u8 *)__u.__c) \
: "Q" (*__p) : "memory"); \
break; \
case 2: \
asm volatile ("ldarh %w0, %1" \
: "=r" (*(__u16 *)__u.__c) \
: "Q" (*__p) : "memory"); \
break; \
case 4: \
asm volatile ("ldar %w0, %1" \
: "=r" (*(__u32 *)__u.__c) \
: "Q" (*__p) : "memory"); \
break; \
case 8: \
asm volatile ("ldar %0, %1" \
: "=r" (*(__u64 *)__u.__c) \
: "Q" (*__p) : "memory"); \
break; \
} \
(typeof(*p))__u.__val; \
})
#define smp_cond_load_relaxed(ptr, cond_expr) \
({ \
typeof(ptr) __PTR = (ptr); \
__unqual_scalar_typeof(*ptr) VAL; \
for (;;) { \
VAL = READ_ONCE(*__PTR); \
if (cond_expr) \
break; \
__cmpwait_relaxed(__PTR, VAL); \
} \
(typeof(*ptr))VAL; \
})
#define smp_cond_load_acquire(ptr, cond_expr) \
({ \
typeof(ptr) __PTR = (ptr); \
__unqual_scalar_typeof(*ptr) VAL; \
for (;;) { \
VAL = smp_load_acquire(__PTR); \
if (cond_expr) \
break; \
__cmpwait_relaxed(__PTR, VAL); \
} \
(typeof(*ptr))VAL; \
})
#include <asm-generic/barrier.h>
#endif /* __ASSEMBLY__ */
#endif /* __ASM_BARRIER_H */
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