83862ccfc0
Xen on arm and arm64 needs SWIOTLB_XEN: when running on Xen we need to program the hardware with mfns rather than pfns for dma addresses. Remove SWIOTLB_XEN dependency on X86 and PCI and make XEN select SWIOTLB_XEN on arm and arm64. At the moment always rely on swiotlb-xen, but when Xen starts supporting hardware IOMMUs we'll be able to avoid it conditionally on the presence of an IOMMU on the platform. Implement xen_create_contiguous_region on arm and arm64: for the moment we assume that dom0 has been mapped 1:1 (physical addresses == machine addresses) therefore we don't need to call XENMEM_exchange. Simply return the physical address as dma address. Initialize the xen-swiotlb from xen_early_init (before the native dma_ops are initialized), set xen_dma_ops to &xen_swiotlb_dma_ops. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Changes in v8: - assume dom0 is mapped 1:1, no need to call XENMEM_exchange. Changes in v7: - call __set_phys_to_machine_multi from xen_create_contiguous_region and xen_destroy_contiguous_region to update the P2M; - don't call XENMEM_unpin, it has been removed; - call XENMEM_exchange instead of XENMEM_exchange_and_pin; - set nr_exchanged to 0 before calling the hypercall. Changes in v6: - introduce and export xen_dma_ops; - call xen_mm_init from as arch_initcall. Changes in v4: - remove redefinition of DMA_ERROR_CODE; - update the code to use XENMEM_exchange_and_pin and XENMEM_unpin; - add a note about hardware IOMMU in the commit message. Changes in v3: - code style changes; - warn on XENMEM_put_dma_buf failures.
64 lines
1.7 KiB
C
64 lines
1.7 KiB
C
#include <linux/bootmem.h>
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#include <linux/gfp.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include <linux/types.h>
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#include <linux/dma-mapping.h>
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#include <linux/vmalloc.h>
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#include <linux/swiotlb.h>
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#include <xen/xen.h>
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#include <xen/interface/memory.h>
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#include <xen/swiotlb-xen.h>
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#include <asm/cacheflush.h>
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#include <asm/xen/page.h>
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#include <asm/xen/hypercall.h>
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#include <asm/xen/interface.h>
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int xen_create_contiguous_region(unsigned long vstart, unsigned int order,
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unsigned int address_bits,
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dma_addr_t *dma_handle)
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{
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if (!xen_initial_domain())
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return -EINVAL;
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/* we assume that dom0 is mapped 1:1 for now */
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*dma_handle = virt_to_phys(pstart);
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return 0;
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}
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EXPORT_SYMBOL_GPL(xen_create_contiguous_region);
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void xen_destroy_contiguous_region(unsigned long vstart, unsigned int order)
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{
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return;
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}
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EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
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struct dma_map_ops *xen_dma_ops;
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EXPORT_SYMBOL_GPL(xen_dma_ops);
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static struct dma_map_ops xen_swiotlb_dma_ops = {
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.mapping_error = xen_swiotlb_dma_mapping_error,
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.alloc = xen_swiotlb_alloc_coherent,
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.free = xen_swiotlb_free_coherent,
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.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
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.sync_single_for_device = xen_swiotlb_sync_single_for_device,
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.sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
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.sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
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.map_sg = xen_swiotlb_map_sg_attrs,
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.unmap_sg = xen_swiotlb_unmap_sg_attrs,
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.map_page = xen_swiotlb_map_page,
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.unmap_page = xen_swiotlb_unmap_page,
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.dma_supported = xen_swiotlb_dma_supported,
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};
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int __init xen_mm_init(void)
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{
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if (!xen_initial_domain())
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return 0;
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xen_swiotlb_init(1, false);
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xen_dma_ops = &xen_swiotlb_dma_ops;
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return 0;
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}
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arch_initcall(xen_mm_init);
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