mirror of https://gitee.com/openkylin/linux.git
95 lines
2.2 KiB
C
95 lines
2.2 KiB
C
#include <linux/cpu.h>
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#include <linux/dma-mapping.h>
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#include <linux/gfp.h>
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#include <linux/highmem.h>
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#include <xen/features.h>
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enum dma_cache_op {
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DMA_UNMAP,
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DMA_MAP,
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};
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/* functions called by SWIOTLB */
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static void dma_cache_maint(dma_addr_t handle, unsigned long offset,
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size_t size, enum dma_data_direction dir, enum dma_cache_op op)
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{
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unsigned long pfn;
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size_t left = size;
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pfn = (handle >> PAGE_SHIFT) + offset / PAGE_SIZE;
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offset %= PAGE_SIZE;
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do {
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size_t len = left;
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/* TODO: cache flush */
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offset = 0;
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pfn++;
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left -= len;
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} while (left);
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}
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static void __xen_dma_page_dev_to_cpu(struct device *hwdev, dma_addr_t handle,
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size_t size, enum dma_data_direction dir)
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{
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dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_UNMAP);
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}
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static void __xen_dma_page_cpu_to_dev(struct device *hwdev, dma_addr_t handle,
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size_t size, enum dma_data_direction dir)
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{
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dma_cache_maint(handle & PAGE_MASK, handle & ~PAGE_MASK, size, dir, DMA_MAP);
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}
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void __xen_dma_map_page(struct device *hwdev, struct page *page,
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dma_addr_t dev_addr, unsigned long offset, size_t size,
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enum dma_data_direction dir, struct dma_attrs *attrs)
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{
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if (is_device_dma_coherent(hwdev))
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return;
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if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
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return;
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__xen_dma_page_cpu_to_dev(hwdev, dev_addr, size, dir);
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}
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void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
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size_t size, enum dma_data_direction dir,
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struct dma_attrs *attrs)
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{
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if (is_device_dma_coherent(hwdev))
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return;
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if (dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs))
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return;
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__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
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}
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void __xen_dma_sync_single_for_cpu(struct device *hwdev,
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dma_addr_t handle, size_t size, enum dma_data_direction dir)
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{
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if (is_device_dma_coherent(hwdev))
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return;
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__xen_dma_page_dev_to_cpu(hwdev, handle, size, dir);
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}
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void __xen_dma_sync_single_for_device(struct device *hwdev,
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dma_addr_t handle, size_t size, enum dma_data_direction dir)
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{
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if (is_device_dma_coherent(hwdev))
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return;
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__xen_dma_page_cpu_to_dev(hwdev, handle, size, dir);
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}
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int __init xen_mm32_init(void)
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{
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if (!xen_initial_domain())
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return 0;
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return 0;
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}
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arch_initcall(xen_mm32_init);
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