mirror of https://gitee.com/openkylin/linux.git
98 lines
2.1 KiB
C
98 lines
2.1 KiB
C
/*
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* safe read and write memory routines callable while atomic
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*
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* Copyright 2005-2008 Analog Devices Inc.
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*
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* Licensed under the GPL-2 or later.
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*/
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#include <linux/uaccess.h>
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#include <asm/dma.h>
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static int validate_memory_access_address(unsigned long addr, int size)
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{
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if (size < 0 || addr == 0)
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return -EFAULT;
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return bfin_mem_access_type(addr, size);
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}
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long probe_kernel_read(void *dst, void *src, size_t size)
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{
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unsigned long lsrc = (unsigned long)src;
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int mem_type;
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mem_type = validate_memory_access_address(lsrc, size);
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if (mem_type < 0)
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return mem_type;
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if (lsrc >= SYSMMR_BASE) {
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if (size == 2 && lsrc % 2 == 0) {
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u16 mmr = bfin_read16(src);
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memcpy(dst, &mmr, sizeof(mmr));
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return 0;
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} else if (size == 4 && lsrc % 4 == 0) {
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u32 mmr = bfin_read32(src);
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memcpy(dst, &mmr, sizeof(mmr));
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return 0;
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}
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} else {
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switch (mem_type) {
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case BFIN_MEM_ACCESS_CORE:
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case BFIN_MEM_ACCESS_CORE_ONLY:
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return __probe_kernel_read(dst, src, size);
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/* XXX: should support IDMA here with SMP */
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case BFIN_MEM_ACCESS_DMA:
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if (dma_memcpy(dst, src, size))
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return 0;
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break;
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case BFIN_MEM_ACCESS_ITEST:
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if (isram_memcpy(dst, src, size))
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return 0;
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break;
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}
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}
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return -EFAULT;
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}
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long probe_kernel_write(void *dst, void *src, size_t size)
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{
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unsigned long ldst = (unsigned long)dst;
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int mem_type;
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mem_type = validate_memory_access_address(ldst, size);
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if (mem_type < 0)
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return mem_type;
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if (ldst >= SYSMMR_BASE) {
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if (size == 2 && ldst % 2 == 0) {
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u16 mmr;
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memcpy(&mmr, src, sizeof(mmr));
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bfin_write16(dst, mmr);
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return 0;
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} else if (size == 4 && ldst % 4 == 0) {
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u32 mmr;
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memcpy(&mmr, src, sizeof(mmr));
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bfin_write32(dst, mmr);
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return 0;
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}
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} else {
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switch (mem_type) {
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case BFIN_MEM_ACCESS_CORE:
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case BFIN_MEM_ACCESS_CORE_ONLY:
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return __probe_kernel_write(dst, src, size);
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/* XXX: should support IDMA here with SMP */
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case BFIN_MEM_ACCESS_DMA:
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if (dma_memcpy(dst, src, size))
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return 0;
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break;
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case BFIN_MEM_ACCESS_ITEST:
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if (isram_memcpy(dst, src, size))
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return 0;
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break;
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}
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}
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return -EFAULT;
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}
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