mirror of https://gitee.com/openkylin/linux.git
51 lines
1.2 KiB
C
51 lines
1.2 KiB
C
/*
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* Copyright (C) 2001 David J. Mckay (david.mckay@st.com)
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* Copyright (C) 2003 Paul Mundt (lethal@linux-sh.org)
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*
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* May be copied or modified under the terms of the GNU General Public
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* License. See linux/COPYING for more information.
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*
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* Dynamic DMA mapping support.
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*/
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#include <linux/types.h>
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#include <linux/mm.h>
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#include <linux/string.h>
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#include <linux/pci.h>
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#include <asm/io.h>
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void *consistent_alloc(struct pci_dev *hwdev, size_t size,
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dma_addr_t *dma_handle)
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{
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void *ret;
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int gfp = GFP_ATOMIC;
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void *vp;
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if (hwdev == NULL || hwdev->dma_mask != 0xffffffff)
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gfp |= GFP_DMA;
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ret = (void *)__get_free_pages(gfp, get_order(size));
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/* now call our friend ioremap_nocache to give us an uncached area */
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vp = ioremap_nocache(virt_to_phys(ret), size);
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if (vp != NULL) {
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memset(vp, 0, size);
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*dma_handle = virt_to_bus(ret);
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dma_cache_wback_inv((unsigned long)ret, size);
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}
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return vp;
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}
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void consistent_free(struct pci_dev *hwdev, size_t size,
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void *vaddr, dma_addr_t dma_handle)
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{
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void *alloc;
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alloc = bus_to_virt((unsigned long)dma_handle);
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free_pages((unsigned long)alloc, get_order(size));
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iounmap(vaddr);
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}
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