drivers/media/video/ivtv/ivtv-udma.c

   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-streams.h"
  25 #include "ivtv-udma.h"
  26
  27 void ivtv_udma_get_page_info(struct ivtv_dma_page_info *dma_page, unsigned long first, unsigned long size)
  28 {
  29         dma_page->uaddr = first & PAGE_MASK;
  30         dma_page->offset = first & ~PAGE_MASK;
  31         dma_page->tail = 1 + ((first+size-1) & ~PAGE_MASK);
  32         dma_page->first = (first & PAGE_MASK) >> PAGE_SHIFT;
  33         dma_page->last = ((first+size-1) & PAGE_MASK) >> PAGE_SHIFT;
  34         dma_page->page_count = dma_page->last - dma_page->first + 1;
  35         if (dma_page->page_count == 1) dma_page->tail -= dma_page->offset;
  36 }
  37
  38 int ivtv_udma_fill_sg_list (struct ivtv_user_dma *dma, struct ivtv_dma_page_info *dma_page, int map_offset)
  39 {
  40         int i, offset;
  41
  42         offset = dma_page->offset;
  43
  44         /* Fill SG Array with new values */
  45         for (i = 0; i < dma_page->page_count; i++) {
  46                 if (i == dma_page->page_count - 1) {
  47                         dma->SGlist[map_offset].length = dma_page->tail;
  48                 }
  49                 else {
  50                         dma->SGlist[map_offset].length = PAGE_SIZE - offset;
  51                 }
  52                 dma->SGlist[map_offset].offset = offset;
  53                 dma->SGlist[map_offset].page = dma->map[map_offset];
  54                 offset = 0;
  55                 map_offset++;
  56         }
  57         return map_offset;
  58 }
  59
  60 void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {
  61         int i;
  62         struct scatterlist *sg;
  63
  64         for (i = 0, sg = dma->SGlist; i < dma->SG_length; i++, sg++) {
  65                 dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));
  66                 dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));
  67                 dma->SGarray[i].dst = cpu_to_le32(buffer_offset);
  68                 buffer_offset += sg_dma_len(sg);
  69
  70                 split -= sg_dma_len(sg);
  71                 if (split == 0)
  72                         buffer_offset = buffer_offset_2;
  73         }
  74 }
  75
  76 /* User DMA Buffers */
  77 void ivtv_udma_alloc(struct ivtv *itv)
  78 {
  79         if (itv->udma.SG_handle == 0) {
  80                 /* Map DMA Page Array Buffer */
  81                 itv->udma.SG_handle = pci_map_single(itv->dev, itv->udma.SGarray,
  82                            sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
  83                 ivtv_udma_sync_for_cpu(itv);
  84         }
  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 err;
  93
  94         IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);
  95
  96         /* Still in USE */
  97         if (dma->SG_length || dma->page_count) {
  98                 IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",
  99                            dma->SG_length, dma->page_count);
 100                 return -EBUSY;
 101         }
 102
 103         ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);
 104
 105         if (user_dma.page_count <= 0) {
 106                 IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",
 107                            user_dma.page_count, size_in_bytes, user_dma.offset);
 108                 return -EINVAL;
 109         }
 110
 111         /* Get user pages for DMA Xfer */
 112         down_read(&current->mm->mmap_sem);
 113         err = get_user_pages(current, current->mm,
 114                         user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
 115         up_read(&current->mm->mmap_sem);
 116
 117         if (user_dma.page_count != err) {
 118                 IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
 119                            err, user_dma.page_count);
 120                 return -EINVAL;
 121         }
 122
 123         dma->page_count = user_dma.page_count;
 124
 125         /* Fill SG List with new values */
 126         ivtv_udma_fill_sg_list(dma, &user_dma, 0);
 127
 128         /* Map SG List */
 129         dma->SG_length = pci_map_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 130
 131         /* Fill SG Array with new values */
 132         ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
 133
 134         /* Tag SG Array with Interrupt Bit */
 135         dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
 136
 137         ivtv_udma_sync_for_device(itv);
 138         return dma->page_count;
 139 }
 140
 141 void ivtv_udma_unmap(struct ivtv *itv)
 142 {
 143         struct ivtv_user_dma *dma = &itv->udma;
 144         int i;
 145
 146         IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
 147
 148         /* Nothing to free */
 149         if (dma->page_count == 0)
 150                 return;
 151
 152         /* Unmap Scatterlist */
 153         if (dma->SG_length) {
 154                 pci_unmap_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 155                 dma->SG_length = 0;
 156         }
 157         /* sync DMA */
 158         ivtv_udma_sync_for_cpu(itv);
 159
 160         /* Release User Pages */
 161         for (i = 0; i < dma->page_count; i++) {
 162                 put_page(dma->map[i]);
 163         }
 164         dma->page_count = 0;
 165 }
 166
 167 void ivtv_udma_free(struct ivtv *itv)
 168 {
 169         /* Unmap SG Array */
 170         if (itv->udma.SG_handle) {
 171                 pci_unmap_single(itv->dev, itv->udma.SG_handle,
 172                          sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
 173         }
 174
 175         /* Unmap Scatterlist */
 176         if (itv->udma.SG_length) {
 177                 pci_unmap_sg(itv->dev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
 178         }
 179 }
 180
 181 void ivtv_udma_start(struct ivtv *itv)
 182 {
 183         IVTV_DEBUG_DMA("start UDMA\n");
 184         write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
 185         write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
 186         set_bit(IVTV_F_I_DMA, &itv->i_flags);
 187         set_bit(IVTV_F_I_UDMA, &itv->i_flags);
 188 }
 189
 190 void ivtv_udma_prepare(struct ivtv *itv)
 191 {
 192         unsigned long flags;
 193
 194         spin_lock_irqsave(&itv->dma_reg_lock, flags);
 195         if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
 196                 ivtv_udma_start(itv);
 197         else
 198                 set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
 199         spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
 200 }