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Diffstat (limited to 'arch/blackfin/mm/maccess.c')
-rw-r--r--arch/blackfin/mm/maccess.c97
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 00000000000..b71cebc1f8a
--- /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;
+}