ivtv-udma.c 6.6 KB

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