drm/prime: split array import functions v4

Mapping the imported pages of a DMA-buf into an userspace process
doesn't work as expected.

But we have reoccurring requests on this approach, so split the
functions for this and  document that dma_buf_mmap() needs to be used
instead.

v2: split it into two functions
v3: rebased on latest changes
v4: update commit message a bit

Signed-off-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/403838/

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index 02748e0..a34fedc 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -918,8 +918,8 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_bo_device *bdev,
                goto release_sg;
 
        /* convert SG to linear array of pages and dma addresses */
-       drm_prime_sg_to_page_addr_arrays(ttm->sg, NULL, gtt->ttm.dma_address,
-                                        ttm->num_pages);
+       drm_prime_sg_to_dma_addr_array(ttm->sg, gtt->ttm.dma_address,
+                                      ttm->num_pages);
 
        return 0;
 
@@ -1264,9 +1264,8 @@ static int amdgpu_ttm_tt_populate(struct ttm_bo_device *bdev,
                        ttm->sg = sgt;
                }
 
-               drm_prime_sg_to_page_addr_arrays(ttm->sg, NULL,
-                                                gtt->ttm.dma_address,
-                                                ttm->num_pages);
+               drm_prime_sg_to_dma_addr_array(ttm->sg, gtt->ttm.dma_address,
+                                              ttm->num_pages);
                return 0;
        }
 

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 7db55fc..683aa29 100644 (file)
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -978,44 +978,58 @@ struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 EXPORT_SYMBOL(drm_gem_prime_import);
 
 /**
- * drm_prime_sg_to_page_addr_arrays - convert an sg table into a page array
+ * drm_prime_sg_to_page_array - convert an sg table into a page array
  * @sgt: scatter-gather table to convert
- * @pages: optional array of page pointers to store the page array in
- * @addrs: optional array to store the dma bus address of each page
+ * @pages: array of page pointers to store the pages in
+ * @max_entries: size of the passed-in array
+ *
+ * Exports an sg table into an array of pages.
+ *
+ * This function is deprecated and strongly discouraged to be used.
+ * The page array is only useful for page faults and those can corrupt fields
+ * in the struct page if they are not handled by the exporting driver.
+ */
+int __deprecated drm_prime_sg_to_page_array(struct sg_table *sgt,
+                                           struct page **pages,
+                                           int max_entries)
+{
+       struct sg_page_iter page_iter;
+       struct page **p = pages;
+
+       for_each_sgtable_page(sgt, &page_iter, 0) {
+               if (WARN_ON(p - pages >= max_entries))
+                       return -1;
+               *p++ = sg_page_iter_page(&page_iter);
+       }
+       return 0;
+}
+EXPORT_SYMBOL(drm_prime_sg_to_page_array);
+
+/**
+ * drm_prime_sg_to_dma_addr_array - convert an sg table into a dma addr array
+ * @sgt: scatter-gather table to convert
+ * @addrs: array to store the dma bus address of each page
  * @max_entries: size of both the passed-in arrays
  *
- * Exports an sg table into an array of pages and addresses. This is currently
- * required by the TTM driver in order to do correct fault handling.
+ * Exports an sg table into an array of addresses.
  *
- * Drivers can use this in their &drm_driver.gem_prime_import_sg_table
+ * Drivers should use this in their &drm_driver.gem_prime_import_sg_table
  * implementation.
  */
-int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
-                                    dma_addr_t *addrs, int max_entries)
+int drm_prime_sg_to_dma_addr_array(struct sg_table *sgt, dma_addr_t *addrs,
+                                  int max_entries)
 {
        struct sg_dma_page_iter dma_iter;
-       struct sg_page_iter page_iter;
-       struct page **p = pages;
        dma_addr_t *a = addrs;
 
-       if (pages) {
-               for_each_sgtable_page(sgt, &page_iter, 0) {
-                       if (WARN_ON(p - pages >= max_entries))
-                               return -1;
-                       *p++ = sg_page_iter_page(&page_iter);
-               }
-       }
-       if (addrs) {
-               for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
-                       if (WARN_ON(a - addrs >= max_entries))
-                               return -1;
-                       *a++ = sg_page_iter_dma_address(&dma_iter);
-               }
+       for_each_sgtable_dma_page(sgt, &dma_iter, 0) {
+               if (WARN_ON(a - addrs >= max_entries))
+                       return -1;
+               *a++ = sg_page_iter_dma_address(&dma_iter);
        }
-
        return 0;
 }
-EXPORT_SYMBOL(drm_prime_sg_to_page_addr_arrays);
+EXPORT_SYMBOL(drm_prime_sg_to_dma_addr_array);
 
 /**
  * drm_prime_gem_destroy - helper to clean up a PRIME-imported GEM object

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index d9bd832..b390dd4 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -135,8 +135,7 @@ struct drm_gem_object *etnaviv_gem_prime_import_sg_table(struct drm_device *dev,
                goto fail;
        }
 
-       ret = drm_prime_sg_to_page_addr_arrays(sgt, etnaviv_obj->pages,
-                                              NULL, npages);
+       ret = drm_prime_sg_to_page_array(sgt, etnaviv_obj->pages, npages);
        if (ret)
                goto fail;
 

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 28a2ee1..280ea0d 100644 (file)
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -260,7 +260,7 @@ int mtk_drm_gem_prime_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
                return -ENOMEM;
        }
 
-       drm_prime_sg_to_page_addr_arrays(sgt, mtk_gem->pages, NULL, npages);
+       drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
 
        mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
                               pgprot_writecombine(PAGE_KERNEL));

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 311721c..f995cb0 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -1180,7 +1180,7 @@ struct drm_gem_object *msm_gem_import(struct drm_device *dev,
                goto fail;
        }
 
-       ret = drm_prime_sg_to_page_addr_arrays(sgt, msm_obj->pages, NULL, npages);
+       ret = drm_prime_sg_to_page_array(sgt, msm_obj->pages, npages);
        if (ret) {
                mutex_unlock(&msm_obj->lock);
                goto fail;

diff --git a/drivers/gpu/drm/nouveau/nouveau_bo.c b/drivers/gpu/drm/nouveau/nouveau_bo.c
index c30f088..645e709 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_bo.c
+++ b/drivers/gpu/drm/nouveau/nouveau_bo.c
@@ -1235,9 +1235,8 @@ nouveau_ttm_tt_populate(struct ttm_bo_device *bdev,
                return 0;
 
        if (slave && ttm->sg) {
-               drm_prime_sg_to_page_addr_arrays(ttm->sg, NULL,
-                                                ttm_dma->dma_address,
-                                                ttm->num_pages);
+               drm_prime_sg_to_dma_addr_array(ttm->sg, ttm_dma->dma_address,
+                                              ttm->num_pages);
                return 0;
        }
 

diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index 30d299c..38af619 100644 (file)
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -1324,8 +1324,7 @@ struct drm_gem_object *omap_gem_new_dmabuf(struct drm_device *dev, size_t size,
                }
 
                omap_obj->pages = pages;
-               ret = drm_prime_sg_to_page_addr_arrays(sgt, pages, NULL,
-                                                      npages);
+               ret = drm_prime_sg_to_page_array(sgt, pages, npages);
                if (ret) {
                        omap_gem_free_object(obj);
                        obj = ERR_PTR(-ENOMEM);

diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 917419b..f1f7adb 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -395,8 +395,8 @@ static int radeon_ttm_tt_pin_userptr(struct ttm_bo_device *bdev, struct ttm_tt *
        if (r)
                goto release_sg;
 
-       drm_prime_sg_to_page_addr_arrays(ttm->sg, NULL, gtt->ttm.dma_address,
-                                        ttm->num_pages);
+       drm_prime_sg_to_dma_addr_array(ttm->sg, gtt->ttm.dma_address,
+                                      ttm->num_pages);
 
        return 0;
 
@@ -574,9 +574,8 @@ static int radeon_ttm_tt_populate(struct ttm_bo_device *bdev,
        }
 
        if (slave && ttm->sg) {
-               drm_prime_sg_to_page_addr_arrays(ttm->sg, NULL,
-                                                gtt->ttm.dma_address,
-                                                ttm->num_pages);
+               drm_prime_sg_to_dma_addr_array(ttm->sg, gtt->ttm.dma_address,
+                                              ttm->num_pages);
                return 0;
        }
 

diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index f8635cc..a0e75f1 100644 (file)
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -356,8 +356,7 @@ static struct drm_gem_object *vgem_prime_import_sg_table(struct drm_device *dev,
        }
 
        obj->pages_pin_count++; /* perma-pinned */
-       drm_prime_sg_to_page_addr_arrays(obj->table, obj->pages, NULL,
-                                       npages);
+       drm_prime_sg_to_page_array(obj->table, obj->pages, npages);
        return &obj->base;
 }
 

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 74db5a8..b293c67 100644 (file)
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -220,8 +220,8 @@ xen_drm_front_gem_import_sg_table(struct drm_device *dev,
 
        xen_obj->sgt_imported = sgt;
 
-       ret = drm_prime_sg_to_page_addr_arrays(sgt, xen_obj->pages,
-                                              NULL, xen_obj->num_pages);
+       ret = drm_prime_sg_to_page_array(sgt, xen_obj->pages,
+                                        xen_obj->num_pages);
        if (ret < 0)
                return ERR_PTR(ret);
 

diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 0991a47..54f2c58 100644 (file)
--- a/include/drm/drm_prime.h
+++ b/include/drm/drm_prime.h
@@ -105,8 +105,9 @@ struct drm_gem_object *drm_gem_prime_import(struct drm_device *dev,
 
 void drm_prime_gem_destroy(struct drm_gem_object *obj, struct sg_table *sg);
 
-int drm_prime_sg_to_page_addr_arrays(struct sg_table *sgt, struct page **pages,
-                                    dma_addr_t *addrs, int max_pages);
-
+int drm_prime_sg_to_page_array(struct sg_table *sgt, struct page **pages,
+                              int max_pages);
+int drm_prime_sg_to_dma_addr_array(struct sg_table *sgt, dma_addr_t *addrs,
+                                  int max_pages);
 
 #endif /* __DRM_PRIME_H__ */