1 /* 2 * Dynamic DMA mapping support. 3 */ 4 5 #include <linux/types.h> 6 #include <linux/mm.h> 7 #include <linux/string.h> 8 #include <linux/pci.h> 9 #include <linux/module.h> 10 #include <linux/dmar.h> 11 #include <asm/iommu.h> 12 #include <asm/machvec.h> 13 #include <linux/dma-mapping.h> 14 15 16 #ifdef CONFIG_INTEL_IOMMU 17 18 #include <linux/kernel.h> 19 20 #include <asm/page.h> 21 22 dma_addr_t bad_dma_address __read_mostly; 23 EXPORT_SYMBOL(bad_dma_address); 24 25 static int iommu_sac_force __read_mostly; 26 27 int no_iommu __read_mostly; 28 #ifdef CONFIG_IOMMU_DEBUG 29 int force_iommu __read_mostly = 1; 30 #else 31 int force_iommu __read_mostly; 32 #endif 33 34 int iommu_pass_through; 35 36 extern struct dma_map_ops intel_dma_ops; 37 38 static int __init pci_iommu_init(void) 39 { 40 if (iommu_detected) 41 intel_iommu_init(); 42 43 return 0; 44 } 45 46 /* Must execute after PCI subsystem */ 47 fs_initcall(pci_iommu_init); 48 49 void pci_iommu_shutdown(void) 50 { 51 return; 52 } 53 54 void __init 55 iommu_dma_init(void) 56 { 57 return; 58 } 59 60 int iommu_dma_supported(struct device *dev, u64 mask) 61 { 62 /* Copied from i386. Doesn't make much sense, because it will 63 only work for pci_alloc_coherent. 64 The caller just has to use GFP_DMA in this case. */ 65 if (mask < DMA_BIT_MASK(24)) 66 return 0; 67 68 /* Tell the device to use SAC when IOMMU force is on. This 69 allows the driver to use cheaper accesses in some cases. 70 71 Problem with this is that if we overflow the IOMMU area and 72 return DAC as fallback address the device may not handle it 73 correctly. 74 75 As a special case some controllers have a 39bit address 76 mode that is as efficient as 32bit (aic79xx). Don't force 77 SAC for these. Assume all masks <= 40 bits are of this 78 type. Normally this doesn't make any difference, but gives 79 more gentle handling of IOMMU overflow. */ 80 if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) { 81 dev_info(dev, "Force SAC with mask %llx\n", mask); 82 return 0; 83 } 84 85 return 1; 86 } 87 EXPORT_SYMBOL(iommu_dma_supported); 88 89 void __init pci_iommu_alloc(void) 90 { 91 dma_ops = &intel_dma_ops; 92 93 intel_dma_ops.sync_single_for_cpu = machvec_dma_sync_single; 94 intel_dma_ops.sync_sg_for_cpu = machvec_dma_sync_sg; 95 intel_dma_ops.sync_single_for_device = machvec_dma_sync_single; 96 intel_dma_ops.sync_sg_for_device = machvec_dma_sync_sg; 97 intel_dma_ops.dma_supported = iommu_dma_supported; 98 99 /* 100 * The order of these functions is important for 101 * fall-back/fail-over reasons 102 */ 103 detect_intel_iommu(); 104 105 #ifdef CONFIG_SWIOTLB 106 pci_swiotlb_init(); 107 #endif 108 } 109 110 #endif 111