ivtv-udma.c 6.5 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-udma.h"
  20. void ivtv_udma_get_page_info(struct ivtv_dma_page_info *dma_page, unsigned long first, unsigned long size)
  21. {
  22. dma_page->uaddr = first & PAGE_MASK;
  23. dma_page->offset = first & ~PAGE_MASK;
  24. dma_page->tail = 1 + ((first+size-1) & ~PAGE_MASK);
  25. dma_page->first = (first & PAGE_MASK) >> PAGE_SHIFT;
  26. dma_page->last = ((first+size-1) & PAGE_MASK) >> PAGE_SHIFT;
  27. dma_page->page_count = dma_page->last - dma_page->first + 1;
  28. if (dma_page->page_count == 1) dma_page->tail -= dma_page->offset;
  29. }
  30. int ivtv_udma_fill_sg_list (struct ivtv_user_dma *dma, struct ivtv_dma_page_info *dma_page, int map_offset)
  31. {
  32. int i, offset;
  33. unsigned long flags;
  34. if (map_offset < 0)
  35. return map_offset;
  36. offset = dma_page->offset;
  37. /* Fill SG Array with new values */
  38. for (i = 0; i < dma_page->page_count; i++) {
  39. unsigned int len = (i == dma_page->page_count - 1) ?
  40. dma_page->tail : PAGE_SIZE - offset;
  41. dma->SGlist[map_offset].length = len;
  42. dma->SGlist[map_offset].offset = offset;
  43. if (PageHighMem(dma->map[map_offset])) {
  44. void *src;
  45. if (dma->bouncemap[map_offset] == NULL)
  46. dma->bouncemap[map_offset] = alloc_page(GFP_KERNEL);
  47. if (dma->bouncemap[map_offset] == NULL)
  48. return -1;
  49. local_irq_save(flags);
  50. src = kmap_atomic(dma->map[map_offset], KM_BOUNCE_READ) + offset;
  51. memcpy(page_address(dma->bouncemap[map_offset]) + offset, src, len);
  52. kunmap_atomic(src, KM_BOUNCE_READ);
  53. local_irq_restore(flags);
  54. sg_set_page(&dma->SGlist[map_offset], dma->bouncemap[map_offset]);
  55. }
  56. else {
  57. sg_set_page(&dma->SGlist[map_offset], dma->map[map_offset]);
  58. }
  59. offset = 0;
  60. map_offset++;
  61. }
  62. return map_offset;
  63. }
  64. void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {
  65. int i;
  66. struct scatterlist *sg;
  67. for (i = 0, sg = dma->SGlist; i < dma->SG_length; i++, sg++) {
  68. dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));
  69. dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));
  70. dma->SGarray[i].dst = cpu_to_le32(buffer_offset);
  71. buffer_offset += sg_dma_len(sg);
  72. split -= sg_dma_len(sg);
  73. if (split == 0)
  74. buffer_offset = buffer_offset_2;
  75. }
  76. }
  77. /* User DMA Buffers */
  78. void ivtv_udma_alloc(struct ivtv *itv)
  79. {
  80. if (itv->udma.SG_handle == 0) {
  81. /* Map DMA Page Array Buffer */
  82. itv->udma.SG_handle = pci_map_single(itv->dev, itv->udma.SGarray,
  83. sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
  84. ivtv_udma_sync_for_cpu(itv);
  85. }
  86. }
  87. int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
  88. void __user *userbuf, int size_in_bytes)
  89. {
  90. struct ivtv_dma_page_info user_dma;
  91. struct ivtv_user_dma *dma = &itv->udma;
  92. int i, err;
  93. IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);
  94. /* Still in USE */
  95. if (dma->SG_length || dma->page_count) {
  96. IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",
  97. dma->SG_length, dma->page_count);
  98. return -EBUSY;
  99. }
  100. ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);
  101. if (user_dma.page_count <= 0) {
  102. IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",
  103. user_dma.page_count, size_in_bytes, user_dma.offset);
  104. return -EINVAL;
  105. }
  106. /* Get user pages for DMA Xfer */
  107. down_read(&current->mm->mmap_sem);
  108. err = get_user_pages(current, current->mm,
  109. user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
  110. up_read(&current->mm->mmap_sem);
  111. if (user_dma.page_count != err) {
  112. IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
  113. err, user_dma.page_count);
  114. return -EINVAL;
  115. }
  116. dma->page_count = user_dma.page_count;
  117. /* Fill SG List with new values */
  118. if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) {
  119. for (i = 0; i < dma->page_count; i++) {
  120. put_page(dma->map[i]);
  121. }
  122. dma->page_count = 0;
  123. return -ENOMEM;
  124. }
  125. /* Map SG List */
  126. dma->SG_length = pci_map_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
  127. /* Fill SG Array with new values */
  128. ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
  129. /* Tag SG Array with Interrupt Bit */
  130. dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
  131. ivtv_udma_sync_for_device(itv);
  132. return dma->page_count;
  133. }
  134. void ivtv_udma_unmap(struct ivtv *itv)
  135. {
  136. struct ivtv_user_dma *dma = &itv->udma;
  137. int i;
  138. IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
  139. /* Nothing to free */
  140. if (dma->page_count == 0)
  141. return;
  142. /* Unmap Scatterlist */
  143. if (dma->SG_length) {
  144. pci_unmap_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
  145. dma->SG_length = 0;
  146. }
  147. /* sync DMA */
  148. ivtv_udma_sync_for_cpu(itv);
  149. /* Release User Pages */
  150. for (i = 0; i < dma->page_count; i++) {
  151. put_page(dma->map[i]);
  152. }
  153. dma->page_count = 0;
  154. }
  155. void ivtv_udma_free(struct ivtv *itv)
  156. {
  157. int i;
  158. /* Unmap SG Array */
  159. if (itv->udma.SG_handle) {
  160. pci_unmap_single(itv->dev, itv->udma.SG_handle,
  161. sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
  162. }
  163. /* Unmap Scatterlist */
  164. if (itv->udma.SG_length) {
  165. pci_unmap_sg(itv->dev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
  166. }
  167. for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) {
  168. if (itv->udma.bouncemap[i])
  169. __free_page(itv->udma.bouncemap[i]);
  170. }
  171. }
  172. void ivtv_udma_start(struct ivtv *itv)
  173. {
  174. IVTV_DEBUG_DMA("start UDMA\n");
  175. write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
  176. write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
  177. set_bit(IVTV_F_I_DMA, &itv->i_flags);
  178. set_bit(IVTV_F_I_UDMA, &itv->i_flags);
  179. }
  180. void ivtv_udma_prepare(struct ivtv *itv)
  181. {
  182. unsigned long flags;
  183. spin_lock_irqsave(&itv->dma_reg_lock, flags);
  184. if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
  185. ivtv_udma_start(itv);
  186. else
  187. set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
  188. spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
  189. }