Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /** |
| 2 | * iommu_fill_pdir - Insert coalesced scatter/gather chunks into the I/O Pdir. |
| 3 | * @ioc: The I/O Controller. |
| 4 | * @startsg: The scatter/gather list of coalesced chunks. |
| 5 | * @nents: The number of entries in the scatter/gather list. |
| 6 | * @hint: The DMA Hint. |
| 7 | * |
| 8 | * This function inserts the coalesced scatter/gather list chunks into the |
| 9 | * I/O Controller's I/O Pdir. |
| 10 | */ |
| 11 | static inline unsigned int |
| 12 | iommu_fill_pdir(struct ioc *ioc, struct scatterlist *startsg, int nents, |
| 13 | unsigned long hint, |
| 14 | void (*iommu_io_pdir_entry)(u64 *, space_t, unsigned long, |
| 15 | unsigned long)) |
| 16 | { |
| 17 | struct scatterlist *dma_sg = startsg; /* pointer to current DMA */ |
| 18 | unsigned int n_mappings = 0; |
| 19 | unsigned long dma_offset = 0, dma_len = 0; |
| 20 | u64 *pdirp = NULL; |
| 21 | |
| 22 | /* Horrible hack. For efficiency's sake, dma_sg starts one |
| 23 | * entry below the true start (it is immediately incremented |
| 24 | * in the loop) */ |
| 25 | dma_sg--; |
| 26 | |
| 27 | while (nents-- > 0) { |
| 28 | unsigned long vaddr; |
| 29 | long size; |
| 30 | |
| 31 | DBG_RUN_SG(" %d : %08lx/%05x %08lx/%05x\n", nents, |
| 32 | (unsigned long)sg_dma_address(startsg), cnt, |
| 33 | sg_virt_addr(startsg), startsg->length |
| 34 | ); |
| 35 | |
| 36 | |
| 37 | /* |
| 38 | ** Look for the start of a new DMA stream |
| 39 | */ |
| 40 | |
| 41 | if (sg_dma_address(startsg) & PIDE_FLAG) { |
| 42 | u32 pide = sg_dma_address(startsg) & ~PIDE_FLAG; |
| 43 | |
| 44 | BUG_ON(pdirp && (dma_len != sg_dma_len(dma_sg))); |
| 45 | |
| 46 | dma_sg++; |
| 47 | |
| 48 | dma_len = sg_dma_len(startsg); |
| 49 | sg_dma_len(startsg) = 0; |
| 50 | dma_offset = (unsigned long) pide & ~IOVP_MASK; |
| 51 | n_mappings++; |
| 52 | #if defined(ZX1_SUPPORT) |
| 53 | /* Pluto IOMMU IO Virt Address is not zero based */ |
| 54 | sg_dma_address(dma_sg) = pide | ioc->ibase; |
| 55 | #else |
| 56 | /* SBA, ccio, and dino are zero based. |
| 57 | * Trying to save a few CPU cycles for most users. |
| 58 | */ |
| 59 | sg_dma_address(dma_sg) = pide; |
| 60 | #endif |
| 61 | pdirp = &(ioc->pdir_base[pide >> IOVP_SHIFT]); |
| 62 | prefetchw(pdirp); |
| 63 | } |
| 64 | |
| 65 | BUG_ON(pdirp == NULL); |
| 66 | |
| 67 | vaddr = sg_virt_addr(startsg); |
| 68 | sg_dma_len(dma_sg) += startsg->length; |
| 69 | size = startsg->length + dma_offset; |
| 70 | dma_offset = 0; |
| 71 | #ifdef IOMMU_MAP_STATS |
| 72 | ioc->msg_pages += startsg->length >> IOVP_SHIFT; |
| 73 | #endif |
| 74 | do { |
| 75 | iommu_io_pdir_entry(pdirp, KERNEL_SPACE, |
| 76 | vaddr, hint); |
| 77 | vaddr += IOVP_SIZE; |
| 78 | size -= IOVP_SIZE; |
| 79 | pdirp++; |
| 80 | } while(unlikely(size > 0)); |
| 81 | startsg++; |
| 82 | } |
| 83 | return(n_mappings); |
| 84 | } |
| 85 | |
| 86 | |
| 87 | /* |
| 88 | ** First pass is to walk the SG list and determine where the breaks are |
| 89 | ** in the DMA stream. Allocates PDIR entries but does not fill them. |
| 90 | ** Returns the number of DMA chunks. |
| 91 | ** |
| 92 | ** Doing the fill separate from the coalescing/allocation keeps the |
| 93 | ** code simpler. Future enhancement could make one pass through |
| 94 | ** the sglist do both. |
| 95 | */ |
| 96 | |
| 97 | static inline unsigned int |
FUJITA Tomonori | d1b5163 | 2008-02-04 22:28:03 -0800 | [diff] [blame] | 98 | iommu_coalesce_chunks(struct ioc *ioc, struct device *dev, |
FUJITA Tomonori | 7c8cda6 | 2008-03-04 14:29:28 -0800 | [diff] [blame^] | 99 | struct scatterlist *startsg, int nents, |
| 100 | int (*iommu_alloc_range)(struct ioc *, struct device *, size_t)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | { |
| 102 | struct scatterlist *contig_sg; /* contig chunk head */ |
| 103 | unsigned long dma_offset, dma_len; /* start/len of DMA stream */ |
| 104 | unsigned int n_mappings = 0; |
FUJITA Tomonori | d1b5163 | 2008-02-04 22:28:03 -0800 | [diff] [blame] | 105 | unsigned int max_seg_size = dma_get_max_seg_size(dev); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | |
| 107 | while (nents > 0) { |
| 108 | |
| 109 | /* |
| 110 | ** Prepare for first/next DMA stream |
| 111 | */ |
| 112 | contig_sg = startsg; |
| 113 | dma_len = startsg->length; |
| 114 | dma_offset = sg_virt_addr(startsg) & ~IOVP_MASK; |
| 115 | |
| 116 | /* PARANOID: clear entries */ |
| 117 | sg_dma_address(startsg) = 0; |
| 118 | sg_dma_len(startsg) = 0; |
| 119 | |
| 120 | /* |
| 121 | ** This loop terminates one iteration "early" since |
| 122 | ** it's always looking one "ahead". |
| 123 | */ |
| 124 | while(--nents > 0) { |
| 125 | unsigned long prevstartsg_end, startsg_end; |
| 126 | |
| 127 | prevstartsg_end = sg_virt_addr(startsg) + |
| 128 | startsg->length; |
| 129 | |
| 130 | startsg++; |
| 131 | startsg_end = sg_virt_addr(startsg) + |
| 132 | startsg->length; |
| 133 | |
| 134 | /* PARANOID: clear entries */ |
| 135 | sg_dma_address(startsg) = 0; |
| 136 | sg_dma_len(startsg) = 0; |
| 137 | |
| 138 | /* |
| 139 | ** First make sure current dma stream won't |
| 140 | ** exceed DMA_CHUNK_SIZE if we coalesce the |
| 141 | ** next entry. |
| 142 | */ |
Milind Arun Choudhary | 3cb1d95 | 2007-03-06 02:44:13 -0800 | [diff] [blame] | 143 | if(unlikely(ALIGN(dma_len + dma_offset + startsg->length, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | IOVP_SIZE) > DMA_CHUNK_SIZE)) |
| 145 | break; |
| 146 | |
FUJITA Tomonori | d1b5163 | 2008-02-04 22:28:03 -0800 | [diff] [blame] | 147 | if (startsg->length + dma_len > max_seg_size) |
| 148 | break; |
| 149 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | /* |
| 151 | ** Next see if we can append the next chunk (i.e. |
| 152 | ** it must end on one page and begin on another |
| 153 | */ |
| 154 | if (unlikely(((prevstartsg_end | sg_virt_addr(startsg)) & ~PAGE_MASK) != 0)) |
| 155 | break; |
| 156 | |
| 157 | dma_len += startsg->length; |
| 158 | } |
| 159 | |
| 160 | /* |
| 161 | ** End of DMA Stream |
| 162 | ** Terminate last VCONTIG block. |
| 163 | ** Allocate space for DMA stream. |
| 164 | */ |
| 165 | sg_dma_len(contig_sg) = dma_len; |
Milind Arun Choudhary | 3cb1d95 | 2007-03-06 02:44:13 -0800 | [diff] [blame] | 166 | dma_len = ALIGN(dma_len + dma_offset, IOVP_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | sg_dma_address(contig_sg) = |
| 168 | PIDE_FLAG |
FUJITA Tomonori | 7c8cda6 | 2008-03-04 14:29:28 -0800 | [diff] [blame^] | 169 | | (iommu_alloc_range(ioc, dev, dma_len) << IOVP_SHIFT) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 170 | | dma_offset; |
| 171 | n_mappings++; |
| 172 | } |
| 173 | |
| 174 | return n_mappings; |
| 175 | } |
| 176 | |