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-rw-r--r--arch/arm64/include/asm/barrier.h216
1 files changed, 216 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
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+++ 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 */