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@xxxxxxxxx>
---
Changes in v2:
- add vkms_gem_vunmap
- use vmap_count to guard against multiple prepare_fb calls on the same fb
Changes in v3:
- change vkms_gem_vmap to retrun int
- cleanup if vmap failed
- increment vmap_count after successful vmap
Changes in v4:
- add err_vmap label
- use out label instead of fail and remove 2 redundant lines
drivers/gpu/drm/vkms/vkms_drv.h | 9 ++++
drivers/gpu/drm/vkms/vkms_gem.c | 79 ++++++++++++++++++++++++++++++++-
2 files changed, 87 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 07be29f2dc44..47048f707566 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);
+int 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..a52e88338c05 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 +179,78 @@ 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);
+ if (vkms_obj->vmap_count < 1) {
+ WARN_ON(vkms_obj->vaddr);
+ WARN_ON(vkms_obj->pages);
+ mutex_unlock(&vkms_obj->pages_lock);
+ return;
+ }
+
+ 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);
+}
+
+int vkms_gem_vmap(struct drm_gem_object *obj)
+{
+ struct vkms_gem_object *vkms_obj = drm_gem_to_vkms_gem(obj);
+ int ret = 0;
+
+ mutex_lock(&vkms_obj->pages_lock);
+
+ 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 out;
+ }
+
+ vkms_obj->vaddr = vmap(pages, n_pages, VM_MAP, PAGE_KERNEL);
+ if (!vkms_obj->vaddr)
+ goto err_vmap;
+
+ vkms_obj->vmap_count++;
+ }
+
+ goto out;
+
+err_vmap:
+ ret = -ENOMEM;
+ drm_gem_put_pages(obj, vkms_obj->pages, false, true);
+ vkms_obj->pages = NULL;
+out:
+ mutex_unlock(&vkms_obj->pages_lock);
+ return ret;
+}
--
2.17.1
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