On Sat, Jul 14, 2018 at 03:18:55PM +0300, Haneen Mohammed wrote:
This patch add the necessary functions to map/unmap GEM backing memory to the kernel's virtual address space.
Signed-off-by: Haneen Mohammed hamohammed.sa@gmail.com
Changes in v2:
- add vkms_gem_vunmap
- use vmap_count to guard against multiple prepare_fb calls on the same fb
drivers/gpu/drm/vkms/vkms_drv.h | 9 ++++ drivers/gpu/drm/vkms/vkms_gem.c | 73 ++++++++++++++++++++++++++++++++- 2 files changed, 81 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index 07be29f2dc44..855e1ea8bc35 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -39,6 +39,8 @@ struct vkms_gem_object { struct drm_gem_object gem; struct mutex pages_lock; /* Page lock used in page fault handler */ struct page **pages;
- unsigned int vmap_count;
- void *vaddr;
};
#define drm_crtc_to_vkms_output(target) \ @@ -47,6 +49,9 @@ struct vkms_gem_object { #define drm_device_to_vkms_device(target) \ container_of(target, struct vkms_device, drm)
+#define drm_gem_to_vkms_gem(target)\
- container_of(target, struct vkms_gem_object, gem)
/* CRTC */ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc, struct drm_plane *primary, struct drm_plane *cursor); @@ -75,4 +80,8 @@ int vkms_dumb_map(struct drm_file *file, struct drm_device *dev,
void vkms_gem_free_object(struct drm_gem_object *obj);
+void *vkms_gem_vmap(struct drm_gem_object *obj);
+void vkms_gem_vunmap(struct drm_gem_object *obj);
#endif /* _VKMS_DRV_H_ */ diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c index c7e38368602b..3f574e761b0f 100644 --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -37,7 +37,9 @@ void vkms_gem_free_object(struct drm_gem_object *obj) struct vkms_gem_object *gem = container_of(obj, struct vkms_gem_object, gem);
- kvfree(gem->pages);
- WARN_ON(gem->pages);
- WARN_ON(gem->vaddr);
- mutex_destroy(&gem->pages_lock); drm_gem_object_release(obj); kfree(gem);
@@ -177,3 +179,72 @@ int vkms_dumb_map(struct drm_file *file, struct drm_device *dev,
return ret; }
+static struct page **_get_pages(struct vkms_gem_object *vkms_obj) +{
- struct drm_gem_object *gem_obj = &vkms_obj->gem;
- if (!vkms_obj->pages) {
struct page **pages = drm_gem_get_pages(gem_obj);if (IS_ERR(pages))return pages;if (cmpxchg(&vkms_obj->pages, NULL, pages))drm_gem_put_pages(gem_obj, pages, false, true);- }
- return vkms_obj->pages;
+}
+void vkms_gem_vunmap(struct drm_gem_object *obj) +{
- struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
- mutex_lock(&vkms_obj->pages_lock);
- WARN_ON(vkms_obj->vmap_count < 1);
- vkms_obj->vmap_count--;
- if (vkms_obj->vmap_count == 0) {
vunmap(vkms_obj->vaddr);vkms_obj->vaddr = NULL;drm_gem_put_pages(obj, vkms_obj->pages, false, true);vkms_obj->pages = NULL;- }
- mutex_unlock(&vkms_obj->pages_lock);
+}
+void *vkms_gem_vmap(struct drm_gem_object *obj) +{
- struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
nit: extra line
- int ret = 0;
- mutex_lock(&vkms_obj->pages_lock);
- vkms_obj->vmap_count++;
If you increment this below the conditional block, you don't need to decrement it in fail.
- if (!vkms_obj->vaddr) {
unsigned int n_pages = obj->size >> PAGE_SHIFT;struct page **pages = _get_pages(vkms_obj);if (IS_ERR(pages)) {ret = PTR_ERR(pages);goto fail;}vkms_obj->vaddr = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);if (!vkms_obj->vaddr) {
Do you need to cleanup from _get_pages() here?
ret = -ENOMEM;goto fail;}- }
- mutex_unlock(&vkms_obj->pages_lock);
- return vkms_obj->vaddr;
+fail:
- vkms_obj->vmap_count--;
- mutex_unlock(&vkms_obj->pages_lock);
- return ERR_PTR(ret);
+}
2.17.1