98 lines
2.1 KiB
C
98 lines
2.1 KiB
C
/*
|
|
* 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;
|
|
}
|