2f91fc331a
Remove code duplication in mm32.c by calling the native dma_ops if the page is a local page (not a foreign page). Use a simple pfn_valid(pfn) check to figure out if the page is local, exploiting the fact that dom0 is mapped 1:1, therefore pfn_valid always returns false when called on a foreign mfn. Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
82 lines
1.9 KiB
C
82 lines
1.9 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_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 (!__generic_dma_ops(hwdev)->unmap_page)
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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 (!__generic_dma_ops(hwdev)->sync_single_for_cpu)
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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 (!__generic_dma_ops(hwdev)->sync_single_for_device)
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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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