From a2c0a97b784f837300f7b0869c82ab712c600952 Mon Sep 17 00:00:00 2001 From: Jesse Barnes Date: Wed, 5 Nov 2008 10:31:53 -0800 Subject: drm: GEM mmap support MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Add core support for mapping of GEM objects. Drivers should provide a vm_operations_struct if they want to support page faulting of objects. The code for handling GEM object offsets was taken from TTM, which was written by Thomas Hellström. Signed-off-by: Jesse Barnes Signed-off-by: Eric Anholt Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_gem.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+) (limited to 'drivers/gpu/drm/drm_gem.c') diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index ccd1afd..b3939de 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -64,6 +64,13 @@ * up at a later date, and as our interface with shmfs for memory allocation. */ +/* + * We make up offsets for buffer objects so we can recognize them at + * mmap time. + */ +#define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1) +#define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16) + /** * Initialize the GEM device fields */ @@ -71,6 +78,8 @@ int drm_gem_init(struct drm_device *dev) { + struct drm_gem_mm *mm; + spin_lock_init(&dev->object_name_lock); idr_init(&dev->object_name_idr); atomic_set(&dev->object_count, 0); @@ -79,9 +88,41 @@ drm_gem_init(struct drm_device *dev) atomic_set(&dev->pin_memory, 0); atomic_set(&dev->gtt_count, 0); atomic_set(&dev->gtt_memory, 0); + + mm = drm_calloc(1, sizeof(struct drm_gem_mm), DRM_MEM_MM); + if (!mm) { + DRM_ERROR("out of memory\n"); + return -ENOMEM; + } + + dev->mm_private = mm; + + if (drm_ht_create(&mm->offset_hash, 19)) { + drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM); + return -ENOMEM; + } + + if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START, + DRM_FILE_PAGE_OFFSET_SIZE)) { + drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM); + drm_ht_remove(&mm->offset_hash); + return -ENOMEM; + } + return 0; } +void +drm_gem_destroy(struct drm_device *dev) +{ + struct drm_gem_mm *mm = dev->mm_private; + + drm_mm_takedown(&mm->offset_manager); + drm_ht_remove(&mm->offset_hash); + drm_free(mm, sizeof(struct drm_gem_mm), DRM_MEM_MM); + dev->mm_private = NULL; +} + /** * Allocate a GEM object of the specified size with shmfs backing store */ @@ -419,3 +460,71 @@ drm_gem_object_handle_free(struct kref *kref) } EXPORT_SYMBOL(drm_gem_object_handle_free); +/** + * drm_gem_mmap - memory map routine for GEM objects + * @filp: DRM file pointer + * @vma: VMA for the area to be mapped + * + * If a driver supports GEM object mapping, mmap calls on the DRM file + * descriptor will end up here. + * + * If we find the object based on the offset passed in (vma->vm_pgoff will + * contain the fake offset we created when the GTT map ioctl was called on + * the object), we set up the driver fault handler so that any accesses + * to the object can be trapped, to perform migration, GTT binding, surface + * register allocation, or performance monitoring. + */ +int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma) +{ + struct drm_file *priv = filp->private_data; + struct drm_device *dev = priv->minor->dev; + struct drm_gem_mm *mm = dev->mm_private; + struct drm_map *map = NULL; + struct drm_gem_object *obj; + struct drm_hash_item *hash; + unsigned long prot; + int ret = 0; + + mutex_lock(&dev->struct_mutex); + + if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) { + mutex_unlock(&dev->struct_mutex); + return drm_mmap(filp, vma); + } + + map = drm_hash_entry(hash, struct drm_map_list, hash)->map; + if (!map || + ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) { + ret = -EPERM; + goto out_unlock; + } + + /* Check for valid size. */ + if (map->size < vma->vm_end - vma->vm_start) { + ret = -EINVAL; + goto out_unlock; + } + + obj = map->handle; + if (!obj->dev->driver->gem_vm_ops) { + ret = -EINVAL; + goto out_unlock; + } + + vma->vm_flags |= VM_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND; + vma->vm_ops = obj->dev->driver->gem_vm_ops; + vma->vm_private_data = map->handle; + /* FIXME: use pgprot_writecombine when available */ + prot = pgprot_val(vma->vm_page_prot); + prot |= _PAGE_CACHE_WC; + vma->vm_page_prot = __pgprot(prot); + + vma->vm_file = filp; /* Needed for drm_vm_open() */ + drm_vm_open_locked(vma); + +out_unlock: + mutex_unlock(&dev->struct_mutex); + + return ret; +} +EXPORT_SYMBOL(drm_gem_mmap); -- cgit v1.1