| David Brazdil | 0f672f6 | 2019-12-10 10:32:29 +0000 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | |
| Andrew Scull | b4b6d4a | 2019-01-02 15:54:55 +0000 | [diff] [blame] | 3 | /* Glue code to lib/swiotlb-xen.c */ |
| 4 | |
| 5 | #include <linux/dma-mapping.h> |
| 6 | #include <linux/pci.h> |
| 7 | #include <xen/swiotlb-xen.h> |
| 8 | |
| 9 | #include <asm/xen/hypervisor.h> |
| 10 | #include <xen/xen.h> |
| 11 | #include <asm/iommu_table.h> |
| 12 | |
| 13 | |
| 14 | #include <asm/xen/swiotlb-xen.h> |
| 15 | #ifdef CONFIG_X86_64 |
| 16 | #include <asm/iommu.h> |
| 17 | #include <asm/dma.h> |
| 18 | #endif |
| 19 | #include <linux/export.h> |
| 20 | |
| 21 | int xen_swiotlb __read_mostly; |
| 22 | |
| 23 | /* |
| 24 | * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary |
| 25 | * |
| 26 | * This returns non-zero if we are forced to use xen_swiotlb (by the boot |
| 27 | * option). |
| 28 | */ |
| 29 | int __init pci_xen_swiotlb_detect(void) |
| 30 | { |
| 31 | |
| 32 | if (!xen_pv_domain()) |
| 33 | return 0; |
| 34 | |
| 35 | /* If running as PV guest, either iommu=soft, or swiotlb=force will |
| 36 | * activate this IOMMU. If running as PV privileged, activate it |
| 37 | * irregardless. |
| 38 | */ |
| 39 | if (xen_initial_domain() || swiotlb || swiotlb_force == SWIOTLB_FORCE) |
| 40 | xen_swiotlb = 1; |
| 41 | |
| 42 | /* If we are running under Xen, we MUST disable the native SWIOTLB. |
| 43 | * Don't worry about swiotlb_force flag activating the native, as |
| 44 | * the 'swiotlb' flag is the only one turning it on. */ |
| 45 | swiotlb = 0; |
| 46 | |
| 47 | #ifdef CONFIG_X86_64 |
| 48 | /* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0 |
| 49 | * (so no iommu=X command line over-writes). |
| 50 | * Considering that PV guests do not want the *native SWIOTLB* but |
| 51 | * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here. |
| 52 | */ |
| 53 | if (max_pfn > MAX_DMA32_PFN) |
| 54 | no_iommu = 1; |
| 55 | #endif |
| 56 | return xen_swiotlb; |
| 57 | } |
| 58 | |
| 59 | void __init pci_xen_swiotlb_init(void) |
| 60 | { |
| 61 | if (xen_swiotlb) { |
| 62 | xen_swiotlb_init(1, true /* early */); |
| 63 | dma_ops = &xen_swiotlb_dma_ops; |
| 64 | |
| 65 | #ifdef CONFIG_PCI |
| 66 | /* Make sure ACS will be enabled */ |
| 67 | pci_request_acs(); |
| 68 | #endif |
| 69 | } |
| 70 | } |
| 71 | |
| 72 | int pci_xen_swiotlb_init_late(void) |
| 73 | { |
| 74 | int rc; |
| 75 | |
| 76 | if (xen_swiotlb) |
| 77 | return 0; |
| 78 | |
| 79 | rc = xen_swiotlb_init(1, false /* late */); |
| 80 | if (rc) |
| 81 | return rc; |
| 82 | |
| 83 | dma_ops = &xen_swiotlb_dma_ops; |
| 84 | #ifdef CONFIG_PCI |
| 85 | /* Make sure ACS will be enabled */ |
| 86 | pci_request_acs(); |
| 87 | #endif |
| 88 | |
| 89 | return 0; |
| 90 | } |
| 91 | EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late); |
| 92 | |
| 93 | IOMMU_INIT_FINISH(pci_xen_swiotlb_detect, |
| 94 | NULL, |
| 95 | pci_xen_swiotlb_init, |
| 96 | NULL); |