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-rw-r--r--arch/arm/include/asm/edac.h38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/arm/include/asm/edac.h b/arch/arm/include/asm/edac.h
new file mode 100644
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+++ b/arch/arm/include/asm/edac.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2011 Calxeda, Inc.
+ * Based on PPC version Copyright 2007 MontaVista Software, Inc.
+ */
+#ifndef ASM_EDAC_H
+#define ASM_EDAC_H
+/*
+ * ECC atomic, DMA, SMP and interrupt safe scrub function.
+ * Implements the per arch edac_atomic_scrub() that EDAC use for software
+ * ECC scrubbing. It reads memory and then writes back the original
+ * value, allowing the hardware to detect and correct memory errors.
+ */
+
+static inline void edac_atomic_scrub(void *va, u32 size)
+{
+#if __LINUX_ARM_ARCH__ >= 6
+ unsigned int *virt_addr = va;
+ unsigned int temp, temp2;
+ unsigned int i;
+
+ for (i = 0; i < size / sizeof(*virt_addr); i++, virt_addr++) {
+ /* Very carefully read and write to memory atomically
+ * so we are interrupt, DMA and SMP safe.
+ */
+ __asm__ __volatile__("\n"
+ "1: ldrex %0, [%2]\n"
+ " strex %1, %0, [%2]\n"
+ " teq %1, #0\n"
+ " bne 1b\n"
+ : "=&r"(temp), "=&r"(temp2)
+ : "r"(virt_addr)
+ : "cc");
+ }
+#endif
+}
+
+#endif