97 lines
2.0 KiB
C
97 lines
2.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Glue code to lib/swiotlb-xen.c */
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#include <linux/dma-mapping.h>
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#include <linux/pci.h>
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#include <xen/swiotlb-xen.h>
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#include <asm/xen/hypervisor.h>
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#include <xen/xen.h>
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#include <asm/iommu_table.h>
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#include <asm/xen/swiotlb-xen.h>
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#ifdef CONFIG_X86_64
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#include <asm/iommu.h>
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#include <asm/dma.h>
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#endif
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#include <linux/export.h>
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int xen_swiotlb __read_mostly;
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/*
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* pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary
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*
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* This returns non-zero if we are forced to use xen_swiotlb (by the boot
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* option).
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*/
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int __init pci_xen_swiotlb_detect(void)
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{
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if (!xen_pv_domain())
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return 0;
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/* If running as PV guest, either iommu=soft, or swiotlb=force will
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* activate this IOMMU. If running as PV privileged, activate it
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* irregardless.
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*/
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if (xen_initial_domain() || swiotlb || swiotlb_force == SWIOTLB_FORCE)
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xen_swiotlb = 1;
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/* If we are running under Xen, we MUST disable the native SWIOTLB.
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* Don't worry about swiotlb_force flag activating the native, as
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* the 'swiotlb' flag is the only one turning it on. */
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swiotlb = 0;
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#ifdef CONFIG_X86_64
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/* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0
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* (so no iommu=X command line over-writes).
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* Considering that PV guests do not want the *native SWIOTLB* but
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* only Xen SWIOTLB it is not useful to us so set no_iommu=1 here.
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*/
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if (max_pfn > MAX_DMA32_PFN)
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no_iommu = 1;
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#endif
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return xen_swiotlb;
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}
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void __init pci_xen_swiotlb_init(void)
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{
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if (xen_swiotlb) {
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xen_swiotlb_init(1, true /* early */);
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dma_ops = &xen_swiotlb_dma_ops;
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#ifdef CONFIG_PCI
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/* Make sure ACS will be enabled */
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pci_request_acs();
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#endif
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}
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}
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int pci_xen_swiotlb_init_late(void)
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{
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int rc;
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if (xen_swiotlb)
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return 0;
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rc = xen_swiotlb_init(1, false /* late */);
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if (rc)
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return rc;
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dma_ops = &xen_swiotlb_dma_ops;
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#ifdef CONFIG_PCI
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/* Make sure ACS will be enabled */
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pci_request_acs();
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#endif
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return 0;
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}
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EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
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IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
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NULL,
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pci_xen_swiotlb_init,
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NULL);
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