Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* $Id: iommu_common.c,v 1.9 2001/12/17 07:05:09 davem Exp $ |
| 2 | * iommu_common.c: UltraSparc SBUS/PCI common iommu code. |
| 3 | * |
| 4 | * Copyright (C) 1999 David S. Miller (davem@redhat.com) |
| 5 | */ |
| 6 | |
| 7 | #include "iommu_common.h" |
| 8 | |
| 9 | /* You are _strongly_ advised to enable the following debugging code |
| 10 | * any time you make changes to the sg code below, run it for a while |
| 11 | * with filesystems mounted read-only before buying the farm... -DaveM |
| 12 | */ |
| 13 | |
| 14 | #ifdef VERIFY_SG |
| 15 | static int verify_lengths(struct scatterlist *sg, int nents, int npages) |
| 16 | { |
| 17 | int sg_len, dma_len; |
| 18 | int i, pgcount; |
| 19 | |
| 20 | sg_len = 0; |
| 21 | for (i = 0; i < nents; i++) |
| 22 | sg_len += sg[i].length; |
| 23 | |
| 24 | dma_len = 0; |
| 25 | for (i = 0; i < nents && sg[i].dma_length; i++) |
| 26 | dma_len += sg[i].dma_length; |
| 27 | |
| 28 | if (sg_len != dma_len) { |
| 29 | printk("verify_lengths: Error, different, sg[%d] dma[%d]\n", |
| 30 | sg_len, dma_len); |
| 31 | return -1; |
| 32 | } |
| 33 | |
| 34 | pgcount = 0; |
| 35 | for (i = 0; i < nents && sg[i].dma_length; i++) { |
| 36 | unsigned long start, end; |
| 37 | |
| 38 | start = sg[i].dma_address; |
| 39 | start = start & IO_PAGE_MASK; |
| 40 | |
| 41 | end = sg[i].dma_address + sg[i].dma_length; |
| 42 | end = (end + (IO_PAGE_SIZE - 1)) & IO_PAGE_MASK; |
| 43 | |
| 44 | pgcount += ((end - start) >> IO_PAGE_SHIFT); |
| 45 | } |
| 46 | |
| 47 | if (pgcount != npages) { |
| 48 | printk("verify_lengths: Error, page count wrong, " |
| 49 | "npages[%d] pgcount[%d]\n", |
| 50 | npages, pgcount); |
| 51 | return -1; |
| 52 | } |
| 53 | |
| 54 | /* This test passes... */ |
| 55 | return 0; |
| 56 | } |
| 57 | |
| 58 | static int verify_one_map(struct scatterlist *dma_sg, struct scatterlist **__sg, int nents, iopte_t **__iopte) |
| 59 | { |
| 60 | struct scatterlist *sg = *__sg; |
| 61 | iopte_t *iopte = *__iopte; |
| 62 | u32 dlen = dma_sg->dma_length; |
| 63 | u32 daddr; |
| 64 | unsigned int sglen; |
| 65 | unsigned long sgaddr; |
| 66 | |
| 67 | daddr = dma_sg->dma_address; |
| 68 | sglen = sg->length; |
| 69 | sgaddr = (unsigned long) (page_address(sg->page) + sg->offset); |
| 70 | while (dlen > 0) { |
| 71 | unsigned long paddr; |
| 72 | |
| 73 | /* SG and DMA_SG must begin at the same sub-page boundary. */ |
| 74 | if ((sgaddr & ~IO_PAGE_MASK) != (daddr & ~IO_PAGE_MASK)) { |
| 75 | printk("verify_one_map: Wrong start offset " |
| 76 | "sg[%08lx] dma[%08x]\n", |
| 77 | sgaddr, daddr); |
| 78 | nents = -1; |
| 79 | goto out; |
| 80 | } |
| 81 | |
| 82 | /* Verify the IOPTE points to the right page. */ |
| 83 | paddr = iopte_val(*iopte) & IOPTE_PAGE; |
| 84 | if ((paddr + PAGE_OFFSET) != (sgaddr & IO_PAGE_MASK)) { |
| 85 | printk("verify_one_map: IOPTE[%08lx] maps the " |
| 86 | "wrong page, should be [%08lx]\n", |
| 87 | iopte_val(*iopte), (sgaddr & IO_PAGE_MASK) - PAGE_OFFSET); |
| 88 | nents = -1; |
| 89 | goto out; |
| 90 | } |
| 91 | |
| 92 | /* If this SG crosses a page, adjust to that next page |
| 93 | * boundary and loop. |
| 94 | */ |
| 95 | if ((sgaddr & IO_PAGE_MASK) ^ ((sgaddr + sglen - 1) & IO_PAGE_MASK)) { |
| 96 | unsigned long next_page, diff; |
| 97 | |
| 98 | next_page = (sgaddr + IO_PAGE_SIZE) & IO_PAGE_MASK; |
| 99 | diff = next_page - sgaddr; |
| 100 | sgaddr += diff; |
| 101 | daddr += diff; |
| 102 | sglen -= diff; |
| 103 | dlen -= diff; |
| 104 | if (dlen > 0) |
| 105 | iopte++; |
| 106 | continue; |
| 107 | } |
| 108 | |
| 109 | /* SG wholly consumed within this page. */ |
| 110 | daddr += sglen; |
| 111 | dlen -= sglen; |
| 112 | |
| 113 | if (dlen > 0 && ((daddr & ~IO_PAGE_MASK) == 0)) |
| 114 | iopte++; |
| 115 | |
| 116 | sg++; |
| 117 | if (--nents <= 0) |
| 118 | break; |
| 119 | sgaddr = (unsigned long) (page_address(sg->page) + sg->offset); |
| 120 | sglen = sg->length; |
| 121 | } |
| 122 | if (dlen < 0) { |
| 123 | /* Transfer overrun, big problems. */ |
| 124 | printk("verify_one_map: Transfer overrun by %d bytes.\n", |
| 125 | -dlen); |
| 126 | nents = -1; |
| 127 | } else { |
| 128 | /* Advance to next dma_sg implies that the next iopte will |
| 129 | * begin it. |
| 130 | */ |
| 131 | iopte++; |
| 132 | } |
| 133 | |
| 134 | out: |
| 135 | *__sg = sg; |
| 136 | *__iopte = iopte; |
| 137 | return nents; |
| 138 | } |
| 139 | |
| 140 | static int verify_maps(struct scatterlist *sg, int nents, iopte_t *iopte) |
| 141 | { |
| 142 | struct scatterlist *dma_sg = sg; |
| 143 | struct scatterlist *orig_dma_sg = dma_sg; |
| 144 | int orig_nents = nents; |
| 145 | |
| 146 | for (;;) { |
| 147 | nents = verify_one_map(dma_sg, &sg, nents, &iopte); |
| 148 | if (nents <= 0) |
| 149 | break; |
| 150 | dma_sg++; |
| 151 | if (dma_sg->dma_length == 0) |
| 152 | break; |
| 153 | } |
| 154 | |
| 155 | if (nents > 0) { |
| 156 | printk("verify_maps: dma maps consumed by some sgs remain (%d)\n", |
| 157 | nents); |
| 158 | return -1; |
| 159 | } |
| 160 | |
| 161 | if (nents < 0) { |
| 162 | printk("verify_maps: Error, messed up mappings, " |
| 163 | "at sg %d dma_sg %d\n", |
| 164 | (int) (orig_nents + nents), (int) (dma_sg - orig_dma_sg)); |
| 165 | return -1; |
| 166 | } |
| 167 | |
| 168 | /* This test passes... */ |
| 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | void verify_sglist(struct scatterlist *sg, int nents, iopte_t *iopte, int npages) |
| 173 | { |
| 174 | if (verify_lengths(sg, nents, npages) < 0 || |
| 175 | verify_maps(sg, nents, iopte) < 0) { |
| 176 | int i; |
| 177 | |
| 178 | printk("verify_sglist: Crap, messed up mappings, dumping, iodma at "); |
| 179 | printk("%016lx.\n", sg->dma_address & IO_PAGE_MASK); |
| 180 | |
| 181 | for (i = 0; i < nents; i++) { |
| 182 | printk("sg(%d): page_addr(%p) off(%x) length(%x) " |
| 183 | "dma_address[%016lx] dma_length[%016lx]\n", |
| 184 | i, |
| 185 | page_address(sg[i].page), sg[i].offset, |
| 186 | sg[i].length, |
| 187 | sg[i].dma_address, sg[i].dma_length); |
| 188 | } |
| 189 | } |
| 190 | |
| 191 | /* Seems to be ok */ |
| 192 | } |
| 193 | #endif |
| 194 | |
| 195 | unsigned long prepare_sg(struct scatterlist *sg, int nents) |
| 196 | { |
| 197 | struct scatterlist *dma_sg = sg; |
| 198 | unsigned long prev; |
| 199 | u32 dent_addr, dent_len; |
| 200 | |
| 201 | prev = (unsigned long) (page_address(sg->page) + sg->offset); |
| 202 | prev += (unsigned long) (dent_len = sg->length); |
| 203 | dent_addr = (u32) ((unsigned long)(page_address(sg->page) + sg->offset) |
| 204 | & (IO_PAGE_SIZE - 1UL)); |
| 205 | while (--nents) { |
| 206 | unsigned long addr; |
| 207 | |
| 208 | sg++; |
| 209 | addr = (unsigned long) (page_address(sg->page) + sg->offset); |
| 210 | if (! VCONTIG(prev, addr)) { |
| 211 | dma_sg->dma_address = dent_addr; |
| 212 | dma_sg->dma_length = dent_len; |
| 213 | dma_sg++; |
| 214 | |
| 215 | dent_addr = ((dent_addr + |
| 216 | dent_len + |
| 217 | (IO_PAGE_SIZE - 1UL)) >> IO_PAGE_SHIFT); |
| 218 | dent_addr <<= IO_PAGE_SHIFT; |
| 219 | dent_addr += addr & (IO_PAGE_SIZE - 1UL); |
| 220 | dent_len = 0; |
| 221 | } |
| 222 | dent_len += sg->length; |
| 223 | prev = addr + sg->length; |
| 224 | } |
| 225 | dma_sg->dma_address = dent_addr; |
| 226 | dma_sg->dma_length = dent_len; |
| 227 | |
| 228 | return ((unsigned long) dent_addr + |
| 229 | (unsigned long) dent_len + |
| 230 | (IO_PAGE_SIZE - 1UL)) >> IO_PAGE_SHIFT; |
| 231 | } |