[PATCH 1/2] drm/mediatek: Implement gem prime vmap/vunmap function

From: CK Hu
Date: Tue Jan 15 2019 - 20:39:38 EST


For some application which need kernel virtual address, such as fbcon,
implement these function to map/unmap kernel virtual address of prime
buffer.

Signed-off-by: CK Hu <ck.hu@xxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_drm_drv.c | 2 ++
drivers/gpu/drm/mediatek/mtk_drm_gem.c | 46 ++++++++++++++++++++++++++
drivers/gpu/drm/mediatek/mtk_drm_gem.h | 3 ++
3 files changed, 51 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 6422e99952fe..6ec4ca070382 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -341,6 +341,8 @@ static struct drm_driver mtk_drm_driver = {
.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
.gem_prime_mmap = mtk_drm_gem_mmap_buf,
+ .gem_prime_vmap = mtk_drm_gem_prime_vmap,
+ .gem_prime_vunmap = mtk_drm_gem_prime_vunmap,
.fops = &mtk_drm_fops,

.name = DRIVER_NAME,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 259b7b0de1d2..38483e9ee071 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -241,3 +241,49 @@ struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
kfree(mtk_gem);
return ERR_PTR(ret);
}
+
+void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj)
+{
+ struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+ struct sg_table *sgt;
+ struct sg_page_iter iter;
+ unsigned int npages;
+ unsigned int i = 0;
+
+ if (mtk_gem->kvaddr)
+ return mtk_gem->kvaddr;
+
+ sgt = mtk_gem_prime_get_sg_table(obj);
+ if (IS_ERR(sgt))
+ return NULL;
+
+ npages = obj->size >> PAGE_SHIFT;
+ mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
+ if (!mtk_gem->pages)
+ goto out;
+
+ for_each_sg_page(sgt->sgl, &iter, sgt->orig_nents, 0) {
+ mtk_gem->pages[i++] = sg_page_iter_page(&iter);
+ if (i > npages)
+ break;
+ }
+ mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
+ pgprot_writecombine(PAGE_KERNEL));
+
+out:
+ kfree((void *)sgt);
+
+ return mtk_gem->kvaddr;
+}
+
+void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
+{
+ struct mtk_drm_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+
+ if (!mtk_gem->pages)
+ return;
+
+ vunmap(vaddr);
+ mtk_gem->kvaddr = 0;
+ kfree((void *)mtk_gem->pages);
+}
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.h b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
index 534639b43a1c..c047a7ef294f 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
@@ -37,6 +37,7 @@ struct mtk_drm_gem_obj {
dma_addr_t dma_addr;
unsigned long dma_attrs;
struct sg_table *sg;
+ struct page **pages;
};

#define to_mtk_gem_obj(x) container_of(x, struct mtk_drm_gem_obj, base)
@@ -52,5 +53,7 @@ int mtk_drm_gem_mmap_buf(struct drm_gem_object *obj,
struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj);
struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
struct dma_buf_attachment *attach, struct sg_table *sg);
+void *mtk_drm_gem_prime_vmap(struct drm_gem_object *obj);
+void mtk_drm_gem_prime_vunmap(struct drm_gem_object *obj, void *vaddr);

#endif
--
2.18.1