drivers/media/pci/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                 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
  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 */
  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
 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
 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
 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
 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
 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 }