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Diffstat (limited to 'arch/arm64/include/asm/barrier.h')
| -rw-r--r-- | arch/arm64/include/asm/barrier.h | 216 |
1 files changed, 216 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h new file mode 100644 index 000000000..2cfc4245d --- /dev/null +++ b/arch/arm64/include/asm/barrier.h @@ -0,0 +1,216 @@ +/* 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 wfet(val) asm volatile("msr s0_3_c1_c0_0, %0" \ + : : "r" (val) : "memory") +#define wfi() asm volatile("wfi" : : : "memory") +#define wfit(val) asm volatile("msr s0_3_c1_c0_1, %0" \ + : : "r" (val) : "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 */ |