1 /*
2 User DMA
3
4 Copyright (C) 2003-2004 Kevin Thayer <nufan_wfk at yahoo.com>
5 Copyright (C) 2004 Chris Kennedy <c@groovy.org>
6 Copyright (C) 2005-2007 Hans Verkuil <hverkuil@xs4all.nl>
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program; if not, write to the Free Software
20 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
21 */
22
23 #include "ivtv-driver.h"
24 #include "ivtv-udma.h"
25
ivtv_udma_get_page_info(struct ivtv_dma_page_info * dma_page,unsigned long first,unsigned long size)26 void ivtv_udma_get_page_info(struct ivtv_dma_page_info *dma_page, unsigned long first, unsigned long size)
27 {
28 dma_page->uaddr = first & PAGE_MASK;
29 dma_page->offset = first & ~PAGE_MASK;
30 dma_page->tail = 1 + ((first+size-1) & ~PAGE_MASK);
31 dma_page->first = (first & PAGE_MASK) >> PAGE_SHIFT;
32 dma_page->last = ((first+size-1) & PAGE_MASK) >> PAGE_SHIFT;
33 dma_page->page_count = dma_page->last - dma_page->first + 1;
34 if (dma_page->page_count == 1) dma_page->tail -= dma_page->offset;
35 }
36
ivtv_udma_fill_sg_list(struct ivtv_user_dma * dma,struct ivtv_dma_page_info * dma_page,int map_offset)37 int ivtv_udma_fill_sg_list (struct ivtv_user_dma *dma, struct ivtv_dma_page_info *dma_page, int map_offset)
38 {
39 int i, offset;
40 unsigned long flags;
41
42 if (map_offset < 0)
43 return map_offset;
44
45 offset = dma_page->offset;
46
47 /* Fill SG Array with new values */
48 for (i = 0; i < dma_page->page_count; i++) {
49 unsigned int len = (i == dma_page->page_count - 1) ?
50 dma_page->tail : PAGE_SIZE - offset;
51
52 if (PageHighMem(dma->map[map_offset])) {
53 void *src;
54
55 if (dma->bouncemap[map_offset] == NULL)
56 dma->bouncemap[map_offset] = alloc_page(GFP_KERNEL);
57 if (dma->bouncemap[map_offset] == NULL)
58 return -1;
59 local_irq_save(flags);
60 src = kmap_atomic(dma->map[map_offset]) + offset;
61 memcpy(page_address(dma->bouncemap[map_offset]) + offset, src, len);
62 kunmap_atomic(src);
63 local_irq_restore(flags);
64 sg_set_page(&dma->SGlist[map_offset], dma->bouncemap[map_offset], len, offset);
65 }
66 else {
67 sg_set_page(&dma->SGlist[map_offset], dma->map[map_offset], len, offset);
68 }
69 offset = 0;
70 map_offset++;
71 }
72 return map_offset;
73 }
74
ivtv_udma_fill_sg_array(struct ivtv_user_dma * dma,u32 buffer_offset,u32 buffer_offset_2,u32 split)75 void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {
76 int i;
77 struct scatterlist *sg;
78
79 for (i = 0, sg = dma->SGlist; i < dma->SG_length; i++, sg = sg_next(sg)) {
80 dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));
81 dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));
82 dma->SGarray[i].dst = cpu_to_le32(buffer_offset);
83 buffer_offset += sg_dma_len(sg);
84
85 split -= sg_dma_len(sg);
86 if (split == 0)
87 buffer_offset = buffer_offset_2;
88 }
89 }
90
91 /* User DMA Buffers */
ivtv_udma_alloc(struct ivtv * itv)92 void ivtv_udma_alloc(struct ivtv *itv)
93 {
94 if (itv->udma.SG_handle == 0) {
95 /* Map DMA Page Array Buffer */
96 itv->udma.SG_handle = pci_map_single(itv->pdev, itv->udma.SGarray,
97 sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
98 ivtv_udma_sync_for_cpu(itv);
99 }
100 }
101
ivtv_udma_setup(struct ivtv * itv,unsigned long ivtv_dest_addr,void __user * userbuf,int size_in_bytes)102 int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
103 void __user *userbuf, int size_in_bytes)
104 {
105 struct ivtv_dma_page_info user_dma;
106 struct ivtv_user_dma *dma = &itv->udma;
107 int i, err;
108
109 IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);
110
111 /* Still in USE */
112 if (dma->SG_length || dma->page_count) {
113 IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",
114 dma->SG_length, dma->page_count);
115 return -EBUSY;
116 }
117
118 ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);
119
120 if (user_dma.page_count <= 0) {
121 IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",
122 user_dma.page_count, size_in_bytes, user_dma.offset);
123 return -EINVAL;
124 }
125
126 /* Get user pages for DMA Xfer */
127 err = get_user_pages_unlocked(current, current->mm,
128 user_dma.uaddr, user_dma.page_count, dma->map,
129 FOLL_FORCE);
130
131 if (user_dma.page_count != err) {
132 IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
133 err, user_dma.page_count);
134 if (err >= 0) {
135 for (i = 0; i < err; i++)
136 put_page(dma->map[i]);
137 return -EINVAL;
138 }
139 return err;
140 }
141
142 dma->page_count = user_dma.page_count;
143
144 /* Fill SG List with new values */
145 if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) {
146 for (i = 0; i < dma->page_count; i++) {
147 put_page(dma->map[i]);
148 }
149 dma->page_count = 0;
150 return -ENOMEM;
151 }
152
153 /* Map SG List */
154 dma->SG_length = pci_map_sg(itv->pdev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
155
156 /* Fill SG Array with new values */
157 ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
158
159 /* Tag SG Array with Interrupt Bit */
160 dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
161
162 ivtv_udma_sync_for_device(itv);
163 return dma->page_count;
164 }
165
ivtv_udma_unmap(struct ivtv * itv)166 void ivtv_udma_unmap(struct ivtv *itv)
167 {
168 struct ivtv_user_dma *dma = &itv->udma;
169 int i;
170
171 IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
172
173 /* Nothing to free */
174 if (dma->page_count == 0)
175 return;
176
177 /* Unmap Scatterlist */
178 if (dma->SG_length) {
179 pci_unmap_sg(itv->pdev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
180 dma->SG_length = 0;
181 }
182 /* sync DMA */
183 ivtv_udma_sync_for_cpu(itv);
184
185 /* Release User Pages */
186 for (i = 0; i < dma->page_count; i++) {
187 put_page(dma->map[i]);
188 }
189 dma->page_count = 0;
190 }
191
ivtv_udma_free(struct ivtv * itv)192 void ivtv_udma_free(struct ivtv *itv)
193 {
194 int i;
195
196 /* Unmap SG Array */
197 if (itv->udma.SG_handle) {
198 pci_unmap_single(itv->pdev, itv->udma.SG_handle,
199 sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
200 }
201
202 /* Unmap Scatterlist */
203 if (itv->udma.SG_length) {
204 pci_unmap_sg(itv->pdev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
205 }
206
207 for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) {
208 if (itv->udma.bouncemap[i])
209 __free_page(itv->udma.bouncemap[i]);
210 }
211 }
212
ivtv_udma_start(struct ivtv * itv)213 void ivtv_udma_start(struct ivtv *itv)
214 {
215 IVTV_DEBUG_DMA("start UDMA\n");
216 write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
217 write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
218 set_bit(IVTV_F_I_DMA, &itv->i_flags);
219 set_bit(IVTV_F_I_UDMA, &itv->i_flags);
220 clear_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
221 }
222
ivtv_udma_prepare(struct ivtv * itv)223 void ivtv_udma_prepare(struct ivtv *itv)
224 {
225 unsigned long flags;
226
227 spin_lock_irqsave(&itv->dma_reg_lock, flags);
228 if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
229 ivtv_udma_start(itv);
230 else
231 set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
232 spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
233 }
234