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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 | // SPDX-License-Identifier: GPL-2.0 #include <linux/dma-direct.h> #include <linux/dma-debug.h> #include <linux/dmar.h> #include <linux/export.h> #include <linux/bootmem.h> #include <linux/gfp.h> #include <linux/pci.h> #include <asm/proto.h> #include <asm/dma.h> #include <asm/iommu.h> #include <asm/gart.h> #include <asm/calgary.h> #include <asm/x86_init.h> #include <asm/iommu_table.h> static bool disable_dac_quirk __read_mostly; const struct dma_map_ops *dma_ops = &dma_direct_ops; EXPORT_SYMBOL(dma_ops); #ifdef CONFIG_IOMMU_DEBUG int panic_on_overflow __read_mostly = 1; int force_iommu __read_mostly = 1; #else int panic_on_overflow __read_mostly = 0; int force_iommu __read_mostly = 0; #endif int iommu_merge __read_mostly = 0; int no_iommu __read_mostly; /* Set this to 1 if there is a HW IOMMU in the system */ int iommu_detected __read_mostly = 0; /* * This variable becomes 1 if iommu=pt is passed on the kernel command line. * If this variable is 1, IOMMU implementations do no DMA translation for * devices and allow every device to access to whole physical memory. This is * useful if a user wants to use an IOMMU only for KVM device assignment to * guests and not for driver dma translation. * It is also possible to disable by default in kernel config, and enable with * iommu=nopt at boot time. */ #ifdef CONFIG_IOMMU_DEFAULT_PASSTHROUGH int iommu_pass_through __read_mostly = 1; #else int iommu_pass_through __read_mostly; #endif extern struct iommu_table_entry __iommu_table[], __iommu_table_end[]; /* Dummy device used for NULL arguments (normally ISA). */ struct device x86_dma_fallback_dev = { .init_name = "fallback device", .coherent_dma_mask = ISA_DMA_BIT_MASK, .dma_mask = &x86_dma_fallback_dev.coherent_dma_mask, }; EXPORT_SYMBOL(x86_dma_fallback_dev); void __init pci_iommu_alloc(void) { struct iommu_table_entry *p; sort_iommu_table(__iommu_table, __iommu_table_end); check_iommu_entries(__iommu_table, __iommu_table_end); for (p = __iommu_table; p < __iommu_table_end; p++) { if (p && p->detect && p->detect() > 0) { p->flags |= IOMMU_DETECTED; if (p->early_init) p->early_init(); if (p->flags & IOMMU_FINISH_IF_DETECTED) break; } } } bool arch_dma_alloc_attrs(struct device **dev) { if (!*dev) *dev = &x86_dma_fallback_dev; if (!is_device_dma_capable(*dev)) return false; return true; } EXPORT_SYMBOL(arch_dma_alloc_attrs); /* * See <Documentation/x86/x86_64/boot-options.txt> for the iommu kernel * parameter documentation. */ static __init int iommu_setup(char *p) { iommu_merge = 1; if (!p) return -EINVAL; while (*p) { if (!strncmp(p, "off", 3)) no_iommu = 1; /* gart_parse_options has more force support */ if (!strncmp(p, "force", 5)) force_iommu = 1; if (!strncmp(p, "noforce", 7)) { iommu_merge = 0; force_iommu = 0; } if (!strncmp(p, "biomerge", 8)) { iommu_merge = 1; force_iommu = 1; } if (!strncmp(p, "panic", 5)) panic_on_overflow = 1; if (!strncmp(p, "nopanic", 7)) panic_on_overflow = 0; if (!strncmp(p, "merge", 5)) { iommu_merge = 1; force_iommu = 1; } if (!strncmp(p, "nomerge", 7)) iommu_merge = 0; if (!strncmp(p, "forcesac", 8)) pr_warn("forcesac option ignored.\n"); if (!strncmp(p, "allowdac", 8)) pr_warn("allowdac option ignored.\n"); if (!strncmp(p, "nodac", 5)) pr_warn("nodac option ignored.\n"); if (!strncmp(p, "usedac", 6)) { disable_dac_quirk = true; return 1; } #ifdef CONFIG_SWIOTLB if (!strncmp(p, "soft", 4)) swiotlb = 1; #endif if (!strncmp(p, "pt", 2)) iommu_pass_through = 1; if (!strncmp(p, "nopt", 4)) iommu_pass_through = 0; gart_parse_options(p); #ifdef CONFIG_CALGARY_IOMMU if (!strncmp(p, "calgary", 7)) use_calgary = 1; #endif /* CONFIG_CALGARY_IOMMU */ p += strcspn(p, ","); if (*p == ',') ++p; } return 0; } early_param("iommu", iommu_setup); static int __init pci_iommu_init(void) { struct iommu_table_entry *p; x86_init.iommu.iommu_init(); for (p = __iommu_table; p < __iommu_table_end; p++) { if (p && (p->flags & IOMMU_DETECTED) && p->late_init) p->late_init(); } return 0; } /* Must execute after PCI subsystem */ rootfs_initcall(pci_iommu_init); #ifdef CONFIG_PCI /* Many VIA bridges seem to corrupt data for DAC. Disable it here */ static int via_no_dac_cb(struct pci_dev *pdev, void *data) { pdev->dev.bus_dma_mask = DMA_BIT_MASK(32); return 0; } static void via_no_dac(struct pci_dev *dev) { if (!disable_dac_quirk) { dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n"); pci_walk_bus(dev->subordinate, via_no_dac_cb, NULL); } } DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, PCI_CLASS_BRIDGE_PCI, 8, via_no_dac); #endif |