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1da177e4 LT |
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 | } |