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Diffstat (limited to 'arch/arm64/include/asm/barrier.h')
-rw-r--r--arch/arm64/include/asm/barrier.h22
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h
index 77651c49ef44..f11518af96a9 100644
--- a/arch/arm64/include/asm/barrier.h
+++ b/arch/arm64/include/asm/barrier.h
@@ -32,6 +32,7 @@
#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
#define psb_csync() asm volatile("hint #17" : : : "memory")
+#define csdb() asm volatile("hint #20" : : : "memory")
#define mb() dsb(sy)
#define rmb() dsb(ld)
@@ -40,6 +41,27 @@
#define dma_rmb() dmb(oshld)
#define dma_wmb() dmb(oshst)
+/*
+ * 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;
+}
+
#define __smp_mb() dmb(ish)
#define __smp_rmb() dmb(ishld)
#define __smp_wmb() dmb(ishst)