160 строки
3.6 KiB
C
160 строки
3.6 KiB
C
/*
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* arch/sh/mm/consistent.c
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*
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* Copyright (C) 2004 - 2007 Paul Mundt
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*
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* Declared coherent memory functions based on arch/x86/kernel/pci-dma_32.c
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/mm.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/dma-mapping.h>
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#include <linux/dma-debug.h>
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#include <linux/io.h>
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#include <linux/module.h>
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#include <linux/gfp.h>
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#include <asm/cacheflush.h>
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#include <asm/addrspace.h>
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#define PREALLOC_DMA_DEBUG_ENTRIES 4096
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struct dma_map_ops *dma_ops;
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EXPORT_SYMBOL(dma_ops);
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static int __init dma_init(void)
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{
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dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
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return 0;
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}
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fs_initcall(dma_init);
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void *dma_generic_alloc_coherent(struct device *dev, size_t size,
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dma_addr_t *dma_handle, gfp_t gfp,
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struct dma_attrs *attrs)
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{
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void *ret, *ret_nocache;
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int order = get_order(size);
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gfp |= __GFP_ZERO;
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ret = (void *)__get_free_pages(gfp, order);
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if (!ret)
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return NULL;
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/*
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* Pages from the page allocator may have data present in
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* cache. So flush the cache before using uncached memory.
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*/
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dma_cache_sync(dev, ret, size, DMA_BIDIRECTIONAL);
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ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size);
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if (!ret_nocache) {
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free_pages((unsigned long)ret, order);
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return NULL;
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}
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split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order);
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*dma_handle = virt_to_phys(ret);
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return ret_nocache;
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}
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void dma_generic_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_handle,
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struct dma_attrs *attrs)
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{
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int order = get_order(size);
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unsigned long pfn = dma_handle >> PAGE_SHIFT;
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int k;
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for (k = 0; k < (1 << order); k++)
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__free_pages(pfn_to_page(pfn + k), 0);
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iounmap(vaddr);
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}
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void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
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enum dma_data_direction direction)
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{
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void *addr;
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addr = __in_29bit_mode() ?
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(void *)CAC_ADDR((unsigned long)vaddr) : vaddr;
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switch (direction) {
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case DMA_FROM_DEVICE: /* invalidate only */
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__flush_invalidate_region(addr, size);
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break;
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case DMA_TO_DEVICE: /* writeback only */
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__flush_wback_region(addr, size);
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break;
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case DMA_BIDIRECTIONAL: /* writeback and invalidate */
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__flush_purge_region(addr, size);
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break;
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default:
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BUG();
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}
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}
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EXPORT_SYMBOL(dma_cache_sync);
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static int __init memchunk_setup(char *str)
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{
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return 1; /* accept anything that begins with "memchunk." */
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}
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__setup("memchunk.", memchunk_setup);
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static void __init memchunk_cmdline_override(char *name, unsigned long *sizep)
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{
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char *p = boot_command_line;
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int k = strlen(name);
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while ((p = strstr(p, "memchunk."))) {
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p += 9; /* strlen("memchunk.") */
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if (!strncmp(name, p, k) && p[k] == '=') {
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p += k + 1;
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*sizep = memparse(p, NULL);
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pr_info("%s: forcing memory chunk size to 0x%08lx\n",
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name, *sizep);
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break;
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}
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}
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}
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int __init platform_resource_setup_memory(struct platform_device *pdev,
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char *name, unsigned long memsize)
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{
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struct resource *r;
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dma_addr_t dma_handle;
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void *buf;
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r = pdev->resource + pdev->num_resources - 1;
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if (r->flags) {
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pr_warning("%s: unable to find empty space for resource\n",
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name);
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return -EINVAL;
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}
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memchunk_cmdline_override(name, &memsize);
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if (!memsize)
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return 0;
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buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL);
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if (!buf) {
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pr_warning("%s: unable to allocate memory\n", name);
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return -ENOMEM;
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}
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memset(buf, 0, memsize);
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r->flags = IORESOURCE_MEM;
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r->start = dma_handle;
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r->end = r->start + memsize - 1;
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r->name = name;
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return 0;
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}
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