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-udma.h"
  25
  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
  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                 dma->SGlist[map_offset].length = len;
  53                 dma->SGlist[map_offset].offset = offset;
  54                 if (PageHighMem(dma->map[map_offset])) {
  55                         void *src;
  56
  57                         if (dma->bouncemap[map_offset] == NULL)
  58                                 dma->bouncemap[map_offset] = alloc_page(GFP_KERNEL);
  59                         if (dma->bouncemap[map_offset] == NULL)
  60                                 return -1;
  61                         local_irq_save(flags);
  62                         src = kmap_atomic(dma->map[map_offset], KM_BOUNCE_READ) + offset;
  63                         memcpy(page_address(dma->bouncemap[map_offset]) + offset, src, len);
  64                         kunmap_atomic(src, KM_BOUNCE_READ);
  65                         local_irq_restore(flags);
  66                         dma->SGlist[map_offset].page = dma->bouncemap[map_offset];
  67                 }
  68                 else {
  69                         dma->SGlist[map_offset].page = dma->map[map_offset];
  70                 }
  71                 offset = 0;
  72                 map_offset++;
  73         }
  74         return map_offset;
  75 }
  76
  77 void ivtv_udma_fill_sg_array (struct ivtv_user_dma *dma, u32 buffer_offset, u32 buffer_offset_2, u32 split) {
  78         int i;
  79         struct scatterlist *sg;
  80
  81         for (i = 0, sg = dma->SGlist; i < dma->SG_length; i++, sg++) {
  82                 dma->SGarray[i].size = cpu_to_le32(sg_dma_len(sg));
  83                 dma->SGarray[i].src = cpu_to_le32(sg_dma_address(sg));
  84                 dma->SGarray[i].dst = cpu_to_le32(buffer_offset);
  85                 buffer_offset += sg_dma_len(sg);
  86
  87                 split -= sg_dma_len(sg);
  88                 if (split == 0)
  89                         buffer_offset = buffer_offset_2;
  90         }
  91 }
  92
  93 /* User DMA Buffers */
  94 void ivtv_udma_alloc(struct ivtv *itv)
  95 {
  96         if (itv->udma.SG_handle == 0) {
  97                 /* Map DMA Page Array Buffer */
  98                 itv->udma.SG_handle = pci_map_single(itv->dev, itv->udma.SGarray,
  99                            sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
 100                 ivtv_udma_sync_for_cpu(itv);
 101         }
 102 }
 103
 104 int ivtv_udma_setup(struct ivtv *itv, unsigned long ivtv_dest_addr,
 105                        void __user *userbuf, int size_in_bytes)
 106 {
 107         struct ivtv_dma_page_info user_dma;
 108         struct ivtv_user_dma *dma = &itv->udma;
 109         int i, err;
 110
 111         IVTV_DEBUG_DMA("ivtv_udma_setup, dst: 0x%08x\n", (unsigned int)ivtv_dest_addr);
 112
 113         /* Still in USE */
 114         if (dma->SG_length || dma->page_count) {
 115                 IVTV_DEBUG_WARN("ivtv_udma_setup: SG_length %d page_count %d still full?\n",
 116                            dma->SG_length, dma->page_count);
 117                 return -EBUSY;
 118         }
 119
 120         ivtv_udma_get_page_info(&user_dma, (unsigned long)userbuf, size_in_bytes);
 121
 122         if (user_dma.page_count <= 0) {
 123                 IVTV_DEBUG_WARN("ivtv_udma_setup: Error %d page_count from %d bytes %d offset\n",
 124                            user_dma.page_count, size_in_bytes, user_dma.offset);
 125                 return -EINVAL;
 126         }
 127
 128         /* Get user pages for DMA Xfer */
 129         down_read(&current->mm->mmap_sem);
 130         err = get_user_pages(current, current->mm,
 131                         user_dma.uaddr, user_dma.page_count, 0, 1, dma->map, NULL);
 132         up_read(&current->mm->mmap_sem);
 133
 134         if (user_dma.page_count != err) {
 135                 IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
 136                            err, user_dma.page_count);
 137                 return -EINVAL;
 138         }
 139
 140         dma->page_count = user_dma.page_count;
 141
 142         /* Fill SG List with new values */
 143         if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) {
 144                 for (i = 0; i < dma->page_count; i++) {
 145                         put_page(dma->map[i]);
 146                 }
 147                 dma->page_count = 0;
 148                 return -ENOMEM;
 149         }
 150
 151         /* Map SG List */
 152         dma->SG_length = pci_map_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 153
 154         /* Fill SG Array with new values */
 155         ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
 156
 157         /* Tag SG Array with Interrupt Bit */
 158         dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
 159
 160         ivtv_udma_sync_for_device(itv);
 161         return dma->page_count;
 162 }
 163
 164 void ivtv_udma_unmap(struct ivtv *itv)
 165 {
 166         struct ivtv_user_dma *dma = &itv->udma;
 167         int i;
 168
 169         IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
 170
 171         /* Nothing to free */
 172         if (dma->page_count == 0)
 173                 return;
 174
 175         /* Unmap Scatterlist */
 176         if (dma->SG_length) {
 177                 pci_unmap_sg(itv->dev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 178                 dma->SG_length = 0;
 179         }
 180         /* sync DMA */
 181         ivtv_udma_sync_for_cpu(itv);
 182
 183         /* Release User Pages */
 184         for (i = 0; i < dma->page_count; i++) {
 185                 put_page(dma->map[i]);
 186         }
 187         dma->page_count = 0;
 188 }
 189
 190 void ivtv_udma_free(struct ivtv *itv)
 191 {
 192         int i;
 193
 194         /* Unmap SG Array */
 195         if (itv->udma.SG_handle) {
 196                 pci_unmap_single(itv->dev, itv->udma.SG_handle,
 197                          sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
 198         }
 199
 200         /* Unmap Scatterlist */
 201         if (itv->udma.SG_length) {
 202                 pci_unmap_sg(itv->dev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
 203         }
 204
 205         for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) {
 206                 if (itv->udma.bouncemap[i])
 207                         __free_page(itv->udma.bouncemap[i]);
 208         }
 209 }
 210
 211 void ivtv_udma_start(struct ivtv *itv)
 212 {
 213         IVTV_DEBUG_DMA("start UDMA\n");
 214         write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
 215         write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
 216         set_bit(IVTV_F_I_DMA, &itv->i_flags);
 217         set_bit(IVTV_F_I_UDMA, &itv->i_flags);
 218 }
 219
 220 void ivtv_udma_prepare(struct ivtv *itv)
 221 {
 222         unsigned long flags;
 223
 224         spin_lock_irqsave(&itv->dma_reg_lock, flags);
 225         if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
 226                 ivtv_udma_start(itv);
 227         else
 228                 set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
 229         spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
 230 }