vcs.maemo.org Git - kernel-power/blob - kernel-power-2.6.28/debian/patches/videobuf-dma-sg-support-non-pagable-user-memory.diff

   1 --- a/drivers/media/video/videobuf-dma-sg.c     2011-11-15 06:09:03.031835263 -0500
   2 +++ b/drivers/media/video/videobuf-dma-sg.c     2011-12-28 07:50:34.514877000 -0500
   3 @@ -137,6 +137,7 @@
   4  {
   5         unsigned long first,last;
   6         int err, rw = 0;
   7 +       struct vm_area_struct *vma;
   8
   9         dma->direction = direction;
  10         switch (dma->direction) {
  11 @@ -154,6 +155,23 @@
  12         last  = ((data+size-1) & PAGE_MASK) >> PAGE_SHIFT;
  13         dma->offset   = data & ~PAGE_MASK;
  14         dma->nr_pages = last-first+1;
  15 +
  16 +       /* In case the buffer is user-allocated and is actually an IO buffer for
  17 +          some other hardware, we cannot map pages for it.  It in fact behaves
  18 +          the same as an overlay. */
  19 +       vma = find_vma (current->mm, data);
  20 +       if (vma && (vma->vm_flags & VM_IO)) {
  21 +               /* Only a single contiguous buffer is supported. */
  22 +               if (vma->vm_end < data + size) {
  23 +                       dprintk(1, "init user: non-contiguous IO buffer.\n");
  24 +                       return -EFAULT; /* same error that get_user_pages() would give */
  25 +               }
  26 +               dma->bus_addr = (vma->vm_pgoff << PAGE_SHIFT) + (data - vma->vm_start);
  27 +               dprintk(1,"init user IO [0x%lx+0x%lx => %d pages at 0x%x]\n",
  28 +                       data, size, dma->nr_pages, dma->bus_addr);
  29 +               return 0;
  30 +       }
  31 +
  32         dma->pages = kmalloc(dma->nr_pages * sizeof(struct page*),
  33                              GFP_KERNEL);
  34         if (NULL == dma->pages)
  35 @@ -231,12 +249,27 @@
  36                                                 (dma->vmalloc,dma->nr_pages);
  37         }
  38         if (dma->bus_addr) {
  39 -               dma->sglist = vmalloc(sizeof(*dma->sglist));
  40 +               unsigned long physp=dma->bus_addr;
  41 +               int i,len;
  42 +
  43 +               len=dma->nr_pages;
  44 +               dma->sglist = vmalloc(len*sizeof(*dma->sglist));
  45 +               sg_init_table(dma->sglist, len);
  46                 if (NULL != dma->sglist) {
  47 -                       dma->sglen  = 1;
  48 -                       sg_dma_address(&dma->sglist[0]) = dma->bus_addr & PAGE_MASK;
  49 -                       dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
  50 -                       sg_dma_len(&dma->sglist[0])     = dma->nr_pages * PAGE_SIZE;
  51 +                       dma->sglist[0].offset           = dma->bus_addr & ~PAGE_MASK;
  52 +                       sg_dma_len(&dma->sglist[0])     = PAGE_SIZE - dma->offset;
  53 +                       sg_dma_address(&dma->sglist[0]) = (dma_addr_t)physp & PAGE_MASK;
  54 +                       physp += sg_dma_len(&dma->sglist[0]);
  55 +                       /*
  56 +                        * Iterate in a loop for the number of pages
  57 +                        */
  58 +                       for (i = 1; i < len; i++) {
  59 +                               dma->sglist[i].offset           = 0;
  60 +                               sg_dma_len(&dma->sglist[i])     = PAGE_SIZE;
  61 +                               sg_dma_address(&dma->sglist[i]) = (dma_addr_t)physp;
  62 +                               physp += PAGE_SIZE;
  63 +                       }
  64 +                       dma->sglen = len;
  65                 }
  66         }
  67         if (NULL == dma->sglist) {
  68 @@ -263,7 +296,7 @@
  69         MAGIC_CHECK(dma->magic, MAGIC_DMABUF);
  70         BUG_ON(!dma->sglen);
  71
  72 -       dma_sync_sg_for_cpu(q->dev, dma->sglist, dma->nr_pages, dma->direction);
  73 +       dma_sync_sg_for_cpu(q->dev, dma->sglist, dma->sglen, dma->direction);
  74         return 0;
  75  }
  76
  77 @@ -273,7 +306,7 @@
  78         if (!dma->sglen)
  79                 return 0;
  80
  81 -       dma_unmap_sg(q->dev, dma->sglist, dma->nr_pages, dma->direction);
  82 +       dma_unmap_sg(q->dev, dma->sglist, dma->sglen, dma->direction);
  83
  84         vfree(dma->sglist);
  85         dma->sglist = NULL;