1 #include <linux/dma-mapping.h> 2 #include <linux/dma-debug.h> 3 #include <linux/dmar.h> 4 #include <linux/bootmem.h> 5 #include <linux/gfp.h> 6 #include <linux/pci.h> 7 #include <linux/kmemleak.h> 8 9 #include <asm/proto.h> 10 #include <asm/dma.h> 11 #include <asm/iommu.h> 12 #include <asm/gart.h> 13 #include <asm/calgary.h> 14 #include <asm/x86_init.h> 15 #include <asm/iommu_table.h> 16 17 static int forbid_dac __read_mostly; 18 19 struct dma_map_ops *dma_ops = &nommu_dma_ops; 20 EXPORT_SYMBOL(dma_ops); 21 22 static int iommu_sac_force __read_mostly; 23 24 #ifdef CONFIG_IOMMU_DEBUG 25 int panic_on_overflow __read_mostly = 1; 26 int force_iommu __read_mostly = 1; 27 #else 28 int panic_on_overflow __read_mostly = 0; 29 int force_iommu __read_mostly = 0; 30 #endif 31 32 int iommu_merge __read_mostly = 0; 33 34 int no_iommu __read_mostly; 35 /* Set this to 1 if there is a HW IOMMU in the system */ 36 int iommu_detected __read_mostly = 0; 37 38 /* 39 * This variable becomes 1 if iommu=pt is passed on the kernel command line. 40 * If this variable is 1, IOMMU implementations do no DMA translation for 41 * devices and allow every device to access to whole physical memory. This is 42 * useful if a user wants to use an IOMMU only for KVM device assignment to 43 * guests and not for driver dma translation. 44 */ 45 int iommu_pass_through __read_mostly; 46 47 extern struct iommu_table_entry __iommu_table[], __iommu_table_end[]; 48 49 /* Dummy device used for NULL arguments (normally ISA). */ 50 struct device x86_dma_fallback_dev = { 51 .init_name = "fallback device", 52 .coherent_dma_mask = ISA_DMA_BIT_MASK, 53 .dma_mask = &x86_dma_fallback_dev.coherent_dma_mask, 54 }; 55 EXPORT_SYMBOL(x86_dma_fallback_dev); 56 57 /* Number of entries preallocated for DMA-API debugging */ 58 #define PREALLOC_DMA_DEBUG_ENTRIES 32768 59 60 int dma_set_mask(struct device *dev, u64 mask) 61 { 62 if (!dev->dma_mask || !dma_supported(dev, mask)) 63 return -EIO; 64 65 *dev->dma_mask = mask; 66 67 return 0; 68 } 69 EXPORT_SYMBOL(dma_set_mask); 70 71 void __init pci_iommu_alloc(void) 72 { 73 struct iommu_table_entry *p; 74 75 sort_iommu_table(__iommu_table, __iommu_table_end); 76 check_iommu_entries(__iommu_table, __iommu_table_end); 77 78 for (p = __iommu_table; p < __iommu_table_end; p++) { 79 if (p && p->detect && p->detect() > 0) { 80 p->flags |= IOMMU_DETECTED; 81 if (p->early_init) 82 p->early_init(); 83 if (p->flags & IOMMU_FINISH_IF_DETECTED) 84 break; 85 } 86 } 87 } 88 void *dma_generic_alloc_coherent(struct device *dev, size_t size, 89 dma_addr_t *dma_addr, gfp_t flag) 90 { 91 unsigned long dma_mask; 92 struct page *page; 93 dma_addr_t addr; 94 95 dma_mask = dma_alloc_coherent_mask(dev, flag); 96 97 flag |= __GFP_ZERO; 98 again: 99 page = alloc_pages_node(dev_to_node(dev), flag, get_order(size)); 100 if (!page) 101 return NULL; 102 103 addr = page_to_phys(page); 104 if (addr + size > dma_mask) { 105 __free_pages(page, get_order(size)); 106 107 if (dma_mask < DMA_BIT_MASK(32) && !(flag & GFP_DMA)) { 108 flag = (flag & ~GFP_DMA32) | GFP_DMA; 109 goto again; 110 } 111 112 return NULL; 113 } 114 115 *dma_addr = addr; 116 return page_address(page); 117 } 118 119 /* 120 * See <Documentation/x86_64/boot-options.txt> for the iommu kernel parameter 121 * documentation. 122 */ 123 static __init int iommu_setup(char *p) 124 { 125 iommu_merge = 1; 126 127 if (!p) 128 return -EINVAL; 129 130 while (*p) { 131 if (!strncmp(p, "off", 3)) 132 no_iommu = 1; 133 /* gart_parse_options has more force support */ 134 if (!strncmp(p, "force", 5)) 135 force_iommu = 1; 136 if (!strncmp(p, "noforce", 7)) { 137 iommu_merge = 0; 138 force_iommu = 0; 139 } 140 141 if (!strncmp(p, "biomerge", 8)) { 142 iommu_merge = 1; 143 force_iommu = 1; 144 } 145 if (!strncmp(p, "panic", 5)) 146 panic_on_overflow = 1; 147 if (!strncmp(p, "nopanic", 7)) 148 panic_on_overflow = 0; 149 if (!strncmp(p, "merge", 5)) { 150 iommu_merge = 1; 151 force_iommu = 1; 152 } 153 if (!strncmp(p, "nomerge", 7)) 154 iommu_merge = 0; 155 if (!strncmp(p, "forcesac", 8)) 156 iommu_sac_force = 1; 157 if (!strncmp(p, "allowdac", 8)) 158 forbid_dac = 0; 159 if (!strncmp(p, "nodac", 5)) 160 forbid_dac = 1; 161 if (!strncmp(p, "usedac", 6)) { 162 forbid_dac = -1; 163 return 1; 164 } 165 #ifdef CONFIG_SWIOTLB 166 if (!strncmp(p, "soft", 4)) 167 swiotlb = 1; 168 #endif 169 if (!strncmp(p, "pt", 2)) 170 iommu_pass_through = 1; 171 172 gart_parse_options(p); 173 174 #ifdef CONFIG_CALGARY_IOMMU 175 if (!strncmp(p, "calgary", 7)) 176 use_calgary = 1; 177 #endif /* CONFIG_CALGARY_IOMMU */ 178 179 p += strcspn(p, ","); 180 if (*p == ',') 181 ++p; 182 } 183 return 0; 184 } 185 early_param("iommu", iommu_setup); 186 187 int dma_supported(struct device *dev, u64 mask) 188 { 189 struct dma_map_ops *ops = get_dma_ops(dev); 190 191 #ifdef CONFIG_PCI 192 if (mask > 0xffffffff && forbid_dac > 0) { 193 dev_info(dev, "PCI: Disallowing DAC for device\n"); 194 return 0; 195 } 196 #endif 197 198 if (ops->dma_supported) 199 return ops->dma_supported(dev, mask); 200 201 /* Copied from i386. Doesn't make much sense, because it will 202 only work for pci_alloc_coherent. 203 The caller just has to use GFP_DMA in this case. */ 204 if (mask < DMA_BIT_MASK(24)) 205 return 0; 206 207 /* Tell the device to use SAC when IOMMU force is on. This 208 allows the driver to use cheaper accesses in some cases. 209 210 Problem with this is that if we overflow the IOMMU area and 211 return DAC as fallback address the device may not handle it 212 correctly. 213 214 As a special case some controllers have a 39bit address 215 mode that is as efficient as 32bit (aic79xx). Don't force 216 SAC for these. Assume all masks <= 40 bits are of this 217 type. Normally this doesn't make any difference, but gives 218 more gentle handling of IOMMU overflow. */ 219 if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) { 220 dev_info(dev, "Force SAC with mask %Lx\n", mask); 221 return 0; 222 } 223 224 return 1; 225 } 226 EXPORT_SYMBOL(dma_supported); 227 228 static int __init pci_iommu_init(void) 229 { 230 struct iommu_table_entry *p; 231 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 232 233 #ifdef CONFIG_PCI 234 dma_debug_add_bus(&pci_bus_type); 235 #endif 236 x86_init.iommu.iommu_init(); 237 238 for (p = __iommu_table; p < __iommu_table_end; p++) { 239 if (p && (p->flags & IOMMU_DETECTED) && p->late_init) 240 p->late_init(); 241 } 242 243 return 0; 244 } 245 /* Must execute after PCI subsystem */ 246 rootfs_initcall(pci_iommu_init); 247 248 #ifdef CONFIG_PCI 249 /* Many VIA bridges seem to corrupt data for DAC. Disable it here */ 250 251 static __devinit void via_no_dac(struct pci_dev *dev) 252 { 253 if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI && forbid_dac == 0) { 254 dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n"); 255 forbid_dac = 1; 256 } 257 } 258 DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID, via_no_dac); 259 #endif 260