130 lines
3.2 KiB
C
130 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Glue code to lib/swiotlb.c */
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#include <linux/pci.h>
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#include <linux/cache.h>
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#include <linux/init.h>
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#include <linux/swiotlb.h>
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#include <linux/bootmem.h>
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#include <linux/dma-mapping.h>
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#include <linux/mem_encrypt.h>
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#include <asm/iommu.h>
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#include <asm/swiotlb.h>
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#include <asm/dma.h>
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#include <asm/xen/swiotlb-xen.h>
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#include <asm/iommu_table.h>
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int swiotlb __read_mostly;
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void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
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dma_addr_t *dma_handle, gfp_t flags,
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unsigned long attrs)
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{
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void *vaddr;
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/*
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* Don't print a warning when the first allocation attempt fails.
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* swiotlb_alloc_coherent() will print a warning when the DMA
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* memory allocation ultimately failed.
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*/
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flags |= __GFP_NOWARN;
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vaddr = dma_generic_alloc_coherent(hwdev, size, dma_handle, flags,
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attrs);
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if (vaddr)
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return vaddr;
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return swiotlb_alloc_coherent(hwdev, size, dma_handle, flags);
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}
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void x86_swiotlb_free_coherent(struct device *dev, size_t size,
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void *vaddr, dma_addr_t dma_addr,
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unsigned long attrs)
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{
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if (is_swiotlb_buffer(dma_to_phys(dev, dma_addr)))
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swiotlb_free_coherent(dev, size, vaddr, dma_addr);
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else
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dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
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}
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static const struct dma_map_ops swiotlb_dma_ops = {
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.mapping_error = swiotlb_dma_mapping_error,
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.alloc = x86_swiotlb_alloc_coherent,
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.free = x86_swiotlb_free_coherent,
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.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
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.sync_single_for_device = swiotlb_sync_single_for_device,
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.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
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.sync_sg_for_device = swiotlb_sync_sg_for_device,
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.map_sg = swiotlb_map_sg_attrs,
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.unmap_sg = swiotlb_unmap_sg_attrs,
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.map_page = swiotlb_map_page,
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.unmap_page = swiotlb_unmap_page,
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.dma_supported = NULL,
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};
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/*
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* pci_swiotlb_detect_override - set swiotlb to 1 if necessary
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*
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* This returns non-zero if we are forced to use swiotlb (by the boot
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* option).
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*/
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int __init pci_swiotlb_detect_override(void)
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{
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if (swiotlb_force == SWIOTLB_FORCE)
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swiotlb = 1;
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return swiotlb;
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}
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IOMMU_INIT_FINISH(pci_swiotlb_detect_override,
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pci_xen_swiotlb_detect,
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pci_swiotlb_init,
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pci_swiotlb_late_init);
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/*
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* If 4GB or more detected (and iommu=off not set) or if SME is active
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* then set swiotlb to 1 and return 1.
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*/
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int __init pci_swiotlb_detect_4gb(void)
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{
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/* don't initialize swiotlb if iommu=off (no_iommu=1) */
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#ifdef CONFIG_X86_64
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if (!no_iommu && max_possible_pfn > MAX_DMA32_PFN)
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swiotlb = 1;
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#endif
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/*
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* If SME is active then swiotlb will be set to 1 so that bounce
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* buffers are allocated and used for devices that do not support
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* the addressing range required for the encryption mask.
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*/
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if (sme_active())
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swiotlb = 1;
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return swiotlb;
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}
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IOMMU_INIT(pci_swiotlb_detect_4gb,
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pci_swiotlb_detect_override,
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pci_swiotlb_init,
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pci_swiotlb_late_init);
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void __init pci_swiotlb_init(void)
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{
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if (swiotlb) {
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swiotlb_init(0);
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dma_ops = &swiotlb_dma_ops;
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}
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}
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void __init pci_swiotlb_late_init(void)
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{
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/* An IOMMU turned us off. */
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if (!swiotlb)
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swiotlb_free();
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else {
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printk(KERN_INFO "PCI-DMA: "
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"Using software bounce buffering for IO (SWIOTLB)\n");
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swiotlb_print_info();
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}
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}
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