1 files changed, 97 insertions, 0 deletions
diff --git a/arch/blackfin/mm/maccess.c b/arch/blackfin/mm/maccess.c
new file mode 100644
index 0000000..b71cebc
--- /dev/null
+++ b/arch/blackfin/mm/maccess.c
@@ -0,0 +1,97 @@
+/*
+ * safe read and write memory routines callable while atomic
+ *
+ * Copyright 2005-2008 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/uaccess.h>
+#include <asm/dma.h>
+
+static int validate_memory_access_address(unsigned long addr, int size)
+{
+	if (size < 0 || addr == 0)
+		return -EFAULT;
+	return bfin_mem_access_type(addr, size);
+}
+
+long probe_kernel_read(void *dst, void *src, size_t size)
+{
+	unsigned long lsrc = (unsigned long)src;
+	int mem_type;
+
+	mem_type = validate_memory_access_address(lsrc, size);
+	if (mem_type < 0)
+		return mem_type;
+
+	if (lsrc >= SYSMMR_BASE) {
+		if (size == 2 && lsrc % 2 == 0) {
+			u16 mmr = bfin_read16(src);
+			memcpy(dst, &mmr, sizeof(mmr));
+			return 0;
+		} else if (size == 4 && lsrc % 4 == 0) {
+			u32 mmr = bfin_read32(src);
+			memcpy(dst, &mmr, sizeof(mmr));
+			return 0;
+		}
+	} else {
+		switch (mem_type) {
+		case BFIN_MEM_ACCESS_CORE:
+		case BFIN_MEM_ACCESS_CORE_ONLY:
+			return __probe_kernel_read(dst, src, size);
+			/* XXX: should support IDMA here with SMP */
+		case BFIN_MEM_ACCESS_DMA:
+			if (dma_memcpy(dst, src, size))
+				return 0;
+			break;
+		case BFIN_MEM_ACCESS_ITEST:
+			if (isram_memcpy(dst, src, size))
+				return 0;
+			break;
+		}
+	}
+
+	return -EFAULT;
+}
+
+long probe_kernel_write(void *dst, void *src, size_t size)
+{
+	unsigned long ldst = (unsigned long)dst;
+	int mem_type;
+
+	mem_type = validate_memory_access_address(ldst, size);
+	if (mem_type < 0)
+		return mem_type;
+
+	if (ldst >= SYSMMR_BASE) {
+		if (size == 2 && ldst % 2 == 0) {
+			u16 mmr;
+			memcpy(&mmr, src, sizeof(mmr));
+			bfin_write16(dst, mmr);
+			return 0;
+		} else if (size == 4 && ldst % 4 == 0) {
+			u32 mmr;
+			memcpy(&mmr, src, sizeof(mmr));
+			bfin_write32(dst, mmr);
+			return 0;
+		}
+	} else {
+		switch (mem_type) {
+		case BFIN_MEM_ACCESS_CORE:
+		case BFIN_MEM_ACCESS_CORE_ONLY:
+			return __probe_kernel_write(dst, src, size);
+			/* XXX: should support IDMA here with SMP */
+		case BFIN_MEM_ACCESS_DMA:
+			if (dma_memcpy(dst, src, size))
+				return 0;
+			break;
+		case BFIN_MEM_ACCESS_ITEST:
+			if (isram_memcpy(dst, src, size))
+				return 0;
+			break;
+		}
+	}
+
+	return -EFAULT;
+}