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 000000000000..b71cebc1f8a3
--- /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;
+}