drm_vm.h

广州斯道2410普及版II的源代码

	offset	 = address - vma->vm_start; /* vm_[pg]off[set] should be 0 */
	page_nr  = offset >> PAGE_SHIFT;
	page = virt_to_page((dma->pagelist[page_nr] + 
			     (offset & (~PAGE_MASK))));

	get_page(page);

	DRM_DEBUG("dma_nopage 0x%lx (page %lu)\n", address, page_nr); 
#if LINUX_VERSION_CODE < 0x020317
	return page_address(page);
#else
	return page;
#endif
}

#if LINUX_VERSION_CODE < 0x020317
unsigned long DRM(vm_sg_nopage)(struct vm_area_struct *vma,
				unsigned long address,
				int unused)
#else
				/* Return type changed in 2.3.23 */
struct page *DRM(vm_sg_nopage)(struct vm_area_struct *vma,
			       unsigned long address,
			       int unused)
#endif
{
#if LINUX_VERSION_CODE >= 0x020300
	drm_map_t        *map    = (drm_map_t *)vma->vm_private_data;
#else
	drm_map_t        *map    = (drm_map_t *)vma->vm_pte;
#endif
	drm_file_t *priv = vma->vm_file->private_data;
	drm_device_t *dev = priv->dev;
	drm_sg_mem_t *entry = dev->sg;
	unsigned long offset;
	unsigned long map_offset;
	unsigned long page_offset;
	struct page *page;

	if (!entry)                return NOPAGE_SIGBUS; /* Error */
	if (address > vma->vm_end) return NOPAGE_SIGBUS; /* Disallow mremap */
	if (!entry->pagelist)      return NOPAGE_OOM ;  /* Nothing allocated */


	offset = address - vma->vm_start;
	map_offset = map->offset - dev->sg->handle;
	page_offset = (offset >> PAGE_SHIFT) + (map_offset >> PAGE_SHIFT);
	page = entry->pagelist[page_offset];
	get_page(page);

#if LINUX_VERSION_CODE < 0x020317
	return page_address(page);
#else
	return page;
#endif
}

void DRM(vm_open)(struct vm_area_struct *vma)
{
	drm_file_t	*priv	= vma->vm_file->private_data;
	drm_device_t	*dev	= priv->dev;
	drm_vma_entry_t *vma_entry;

	DRM_DEBUG("0x%08lx,0x%08lx\n",
		  vma->vm_start, vma->vm_end - vma->vm_start);
	atomic_inc(&dev->vma_count);
#if LINUX_VERSION_CODE < 0x020333
				/* The map can exist after the fd is closed. */
	MOD_INC_USE_COUNT; /* Needed before Linux 2.3.51 */
#endif

	vma_entry = DRM(alloc)(sizeof(*vma_entry), DRM_MEM_VMAS);
	if (vma_entry) {
		down(&dev->struct_sem);
		vma_entry->vma	= vma;
		vma_entry->next = dev->vmalist;
		vma_entry->pid	= current->pid;
		dev->vmalist	= vma_entry;
		up(&dev->struct_sem);
	}
}

void DRM(vm_close)(struct vm_area_struct *vma)
{
	drm_file_t	*priv	= vma->vm_file->private_data;
	drm_device_t	*dev	= priv->dev;
	drm_vma_entry_t *pt, *prev;

	DRM_DEBUG("0x%08lx,0x%08lx\n",
		  vma->vm_start, vma->vm_end - vma->vm_start);
#if LINUX_VERSION_CODE < 0x020333
	MOD_DEC_USE_COUNT; /* Needed before Linux 2.3.51 */
#endif
	atomic_dec(&dev->vma_count);

	down(&dev->struct_sem);
	for (pt = dev->vmalist, prev = NULL; pt; prev = pt, pt = pt->next) {
		if (pt->vma == vma) {
			if (prev) {
				prev->next = pt->next;
			} else {
				dev->vmalist = pt->next;
			}
			DRM(free)(pt, sizeof(*pt), DRM_MEM_VMAS);
			break;
		}
	}
	up(&dev->struct_sem);
}

int DRM(mmap_dma)(struct file *filp, struct vm_area_struct *vma)
{
	drm_file_t	 *priv	 = filp->private_data;
	drm_device_t	 *dev;
	drm_device_dma_t *dma;
	unsigned long	 length	 = vma->vm_end - vma->vm_start;

	lock_kernel();
	dev	 = priv->dev;
	dma	 = dev->dma;
	DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
		  vma->vm_start, vma->vm_end, VM_OFFSET(vma));

				/* Length must match exact page count */
	if (!dma || (length >> PAGE_SHIFT) != dma->page_count) {
		unlock_kernel();
		return -EINVAL;
	}
	unlock_kernel();

	vma->vm_ops   = &DRM(vm_dma_ops);
	vma->vm_flags |= VM_RESERVED; /* Don't swap */

#if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
				/* In Linux 2.2.3 and above, this is
				   handled in do_mmap() in mm/mmap.c. */
	++filp->f_count;
#endif
	vma->vm_file  =	 filp;	/* Needed for drm_vm_open() */
	DRM(vm_open)(vma);
	return 0;
}

#ifndef DRIVER_GET_MAP_OFS
#define DRIVER_GET_MAP_OFS()	(map->offset)
#endif

#ifndef DRIVER_GET_REG_OFS
#ifdef __alpha__
#define DRIVER_GET_REG_OFS()	(dev->hose->dense_mem_base -	\
				 dev->hose->mem_space->start)
#else
#define DRIVER_GET_REG_OFS()	0
#endif
#endif

int DRM(mmap)(struct file *filp, struct vm_area_struct *vma)
{
	drm_file_t	*priv	= filp->private_data;
	drm_device_t	*dev	= priv->dev;
	drm_map_t	*map	= NULL;
	drm_map_list_t  *r_list;
	unsigned long   offset  = 0;
	struct list_head *list;

	DRM_DEBUG("start = 0x%lx, end = 0x%lx, offset = 0x%lx\n",
		  vma->vm_start, vma->vm_end, VM_OFFSET(vma));

	if ( !priv->authenticated ) return -EACCES;

	if (!VM_OFFSET(vma)) return DRM(mmap_dma)(filp, vma);

				/* A sequential search of a linked list is
				   fine here because: 1) there will only be
				   about 5-10 entries in the list and, 2) a
				   DRI client only has to do this mapping
				   once, so it doesn't have to be optimized
				   for performance, even if the list was a
				   bit longer. */
	list_for_each(list, &dev->maplist->head) {
		unsigned long off;

		r_list = (drm_map_list_t *)list;
		map = r_list->map;
		if (!map) continue;
		off = DRIVER_GET_MAP_OFS();
		if (off == VM_OFFSET(vma)) break;
	}

	if (!map || ((map->flags&_DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN)))
		return -EPERM;

				/* Check for valid size. */
	if (map->size != vma->vm_end - vma->vm_start) return -EINVAL;

	if (!capable(CAP_SYS_ADMIN) && (map->flags & _DRM_READ_ONLY)) {
		vma->vm_flags &= VM_MAYWRITE;
#if defined(__i386__)
		pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
#else
				/* Ye gads this is ugly.  With more thought
                                   we could move this up higher and use
                                   `protection_map' instead.  */
		vma->vm_page_prot = __pgprot(pte_val(pte_wrprotect(
			__pte(pgprot_val(vma->vm_page_prot)))));
#endif
	}

	switch (map->type) {
        case _DRM_AGP:
#if defined(__alpha__)
                /*
                 * On Alpha we can't talk to bus dma address from the
                 * CPU, so for memory of type DRM_AGP, we'll deal with
                 * sorting out the real physical pages and mappings
                 * in nopage()
                 */
                vma->vm_ops = &DRM(vm_ops);
                break;
#endif
                /* fall through to _DRM_FRAME_BUFFER... */        
	case _DRM_FRAME_BUFFER:
	case _DRM_REGISTERS:
		if (VM_OFFSET(vma) >= __pa(high_memory)) {
#if defined(__i386__)
			if (boot_cpu_data.x86 > 3 && map->type != _DRM_AGP) {
				pgprot_val(vma->vm_page_prot) |= _PAGE_PCD;
				pgprot_val(vma->vm_page_prot) &= ~_PAGE_PWT;
			}
#elif defined(__ia64__)
			if (map->type != _DRM_AGP)
				vma->vm_page_prot =
					pgprot_writecombine(vma->vm_page_prot);
#elif defined(__powerpc__)
			pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE | _PAGE_GUARDED;
#endif
			vma->vm_flags |= VM_IO;	/* not in core dump */
		}
		offset = DRIVER_GET_REG_OFS();
#ifdef __sparc__
		if (io_remap_page_range(vma->vm_start,
					VM_OFFSET(vma) + offset,
					vma->vm_end - vma->vm_start,
					vma->vm_page_prot, 0))
#else
		if (remap_page_range(vma->vm_start,
				     VM_OFFSET(vma) + offset,
				     vma->vm_end - vma->vm_start,
				     vma->vm_page_prot))
#endif
				return -EAGAIN;
		DRM_DEBUG("   Type = %d; start = 0x%lx, end = 0x%lx,"
			  " offset = 0x%lx\n",
			  map->type,
			  vma->vm_start, vma->vm_end, VM_OFFSET(vma) + offset);
		vma->vm_ops = &DRM(vm_ops);
		break;
	case _DRM_SHM:
		vma->vm_ops = &DRM(vm_shm_ops);
#if LINUX_VERSION_CODE >= 0x020300
		vma->vm_private_data = (void *)map;
#else
		vma->vm_pte = (unsigned long)map;
#endif
				/* Don't let this area swap.  Change when
				   DRM_KERNEL advisory is supported. */
		vma->vm_flags |= VM_RESERVED;
		break;
	case _DRM_SCATTER_GATHER:
		vma->vm_ops = &DRM(vm_sg_ops);
#if LINUX_VERSION_CODE >= 0x020300
		vma->vm_private_data = (void *)map;
#else
		vma->vm_pte = (unsigned long)map;
#endif
                vma->vm_flags |= VM_RESERVED;
                break;
	default:
		return -EINVAL;	/* This should never happen. */
	}
	vma->vm_flags |= VM_RESERVED; /* Don't swap */

#if LINUX_VERSION_CODE < 0x020203 /* KERNEL_VERSION(2,2,3) */
				/* In Linux 2.2.3 and above, this is
				   handled in do_mmap() in mm/mmap.c. */
	++filp->f_count;
#endif
	vma->vm_file  =	 filp;	/* Needed for drm_vm_open() */
	DRM(vm_open)(vma);
	return 0;
}