linux/drivers/media/pci/ivtv/ivtv-udma.c
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   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
  26void 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
  37int 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
  75void 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 */
  92void 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
 102int 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, 0, 1, dma->map);
 129
 130        if (user_dma.page_count != err) {
 131                IVTV_DEBUG_WARN("failed to map user pages, returned %d instead of %d\n",
 132                           err, user_dma.page_count);
 133                if (err >= 0) {
 134                        for (i = 0; i < err; i++)
 135                                put_page(dma->map[i]);
 136                        return -EINVAL;
 137                }
 138                return err;
 139        }
 140
 141        dma->page_count = user_dma.page_count;
 142
 143        /* Fill SG List with new values */
 144        if (ivtv_udma_fill_sg_list(dma, &user_dma, 0) < 0) {
 145                for (i = 0; i < dma->page_count; i++) {
 146                        put_page(dma->map[i]);
 147                }
 148                dma->page_count = 0;
 149                return -ENOMEM;
 150        }
 151
 152        /* Map SG List */
 153        dma->SG_length = pci_map_sg(itv->pdev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 154
 155        /* Fill SG Array with new values */
 156        ivtv_udma_fill_sg_array (dma, ivtv_dest_addr, 0, -1);
 157
 158        /* Tag SG Array with Interrupt Bit */
 159        dma->SGarray[dma->SG_length - 1].size |= cpu_to_le32(0x80000000);
 160
 161        ivtv_udma_sync_for_device(itv);
 162        return dma->page_count;
 163}
 164
 165void ivtv_udma_unmap(struct ivtv *itv)
 166{
 167        struct ivtv_user_dma *dma = &itv->udma;
 168        int i;
 169
 170        IVTV_DEBUG_INFO("ivtv_unmap_user_dma\n");
 171
 172        /* Nothing to free */
 173        if (dma->page_count == 0)
 174                return;
 175
 176        /* Unmap Scatterlist */
 177        if (dma->SG_length) {
 178                pci_unmap_sg(itv->pdev, dma->SGlist, dma->page_count, PCI_DMA_TODEVICE);
 179                dma->SG_length = 0;
 180        }
 181        /* sync DMA */
 182        ivtv_udma_sync_for_cpu(itv);
 183
 184        /* Release User Pages */
 185        for (i = 0; i < dma->page_count; i++) {
 186                put_page(dma->map[i]);
 187        }
 188        dma->page_count = 0;
 189}
 190
 191void ivtv_udma_free(struct ivtv *itv)
 192{
 193        int i;
 194
 195        /* Unmap SG Array */
 196        if (itv->udma.SG_handle) {
 197                pci_unmap_single(itv->pdev, itv->udma.SG_handle,
 198                         sizeof(itv->udma.SGarray), PCI_DMA_TODEVICE);
 199        }
 200
 201        /* Unmap Scatterlist */
 202        if (itv->udma.SG_length) {
 203                pci_unmap_sg(itv->pdev, itv->udma.SGlist, itv->udma.page_count, PCI_DMA_TODEVICE);
 204        }
 205
 206        for (i = 0; i < IVTV_DMA_SG_OSD_ENT; i++) {
 207                if (itv->udma.bouncemap[i])
 208                        __free_page(itv->udma.bouncemap[i]);
 209        }
 210}
 211
 212void ivtv_udma_start(struct ivtv *itv)
 213{
 214        IVTV_DEBUG_DMA("start UDMA\n");
 215        write_reg(itv->udma.SG_handle, IVTV_REG_DECDMAADDR);
 216        write_reg_sync(read_reg(IVTV_REG_DMAXFER) | 0x01, IVTV_REG_DMAXFER);
 217        set_bit(IVTV_F_I_DMA, &itv->i_flags);
 218        set_bit(IVTV_F_I_UDMA, &itv->i_flags);
 219        clear_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
 220}
 221
 222void ivtv_udma_prepare(struct ivtv *itv)
 223{
 224        unsigned long flags;
 225
 226        spin_lock_irqsave(&itv->dma_reg_lock, flags);
 227        if (!test_bit(IVTV_F_I_DMA, &itv->i_flags))
 228                ivtv_udma_start(itv);
 229        else
 230                set_bit(IVTV_F_I_UDMA_PENDING, &itv->i_flags);
 231        spin_unlock_irqrestore(&itv->dma_reg_lock, flags);
 232}
 233