drm: allow limiting the scatter list size.

Add drm_device argument to drm_prime_pages_to_sg(), so we can
call dma_max_mapping_size() to figure the segment size limit
and call into __sg_alloc_table_from_pages() with the correct
limit.

This fixes virtio-gpu with sev.  Possibly it'll fix other bugs
too given that drm seems to totaly ignore segment size limits
so far ...

v2: place max_segment in drm driver not gem object.
v3: move max_segment next to the other gem fields.
v4: just use dma_max_mapping_size().

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20200907112425.15610-2-kraxel@redhat.com

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index 519ce44..d7050ab 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -302,7 +302,8 @@ static struct sg_table *amdgpu_dma_buf_map(struct dma_buf_attachment *attach,
 
        switch (bo->tbo.mem.mem_type) {
        case TTM_PL_TT:
-               sgt = drm_prime_pages_to_sg(bo->tbo.ttm->pages,
+               sgt = drm_prime_pages_to_sg(obj->dev,
+                                           bo->tbo.ttm->pages,
                                            bo->tbo.num_pages);
                if (IS_ERR(sgt))
                        return sgt;

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 4b7cfba..0a952f2 100644 (file)
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -656,7 +656,7 @@ struct sg_table *drm_gem_shmem_get_sg_table(struct drm_gem_object *obj)
 
        WARN_ON(shmem->base.import_attach);
 
-       return drm_prime_pages_to_sg(shmem->pages, obj->size >> PAGE_SHIFT);
+       return drm_prime_pages_to_sg(obj->dev, shmem->pages, obj->size >> PAGE_SHIFT);
 }
 EXPORT_SYMBOL_GPL(drm_gem_shmem_get_sg_table);
 

diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 1693aa7..8a6a3c9 100644 (file)
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -802,9 +802,11 @@ static const struct dma_buf_ops drm_gem_prime_dmabuf_ops =  {
  *
  * This is useful for implementing &drm_gem_object_funcs.get_sg_table.
  */
-struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_pages)
+struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev,
+                                      struct page **pages, unsigned int nr_pages)
 {
        struct sg_table *sg = NULL;
+       size_t max_segment = 0;
        int ret;
 
        sg = kmalloc(sizeof(struct sg_table), GFP_KERNEL);
@@ -813,8 +815,13 @@ struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_page
                goto out;
        }
 
-       ret = sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
-                               nr_pages << PAGE_SHIFT, GFP_KERNEL);
+       if (dev)
+               max_segment = dma_max_mapping_size(dev->dev);
+       if (max_segment == 0 || max_segment > SCATTERLIST_MAX_SEGMENT)
+               max_segment = SCATTERLIST_MAX_SEGMENT;
+       ret = __sg_alloc_table_from_pages(sg, pages, nr_pages, 0,
+                                         nr_pages << PAGE_SHIFT,
+                                         max_segment, GFP_KERNEL);
        if (ret)
                goto out;
 

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index f06e19e..ea19f1d 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -103,7 +103,8 @@ struct page **etnaviv_gem_get_pages(struct etnaviv_gem_object *etnaviv_obj)
                int npages = etnaviv_obj->base.size >> PAGE_SHIFT;
                struct sg_table *sgt;
 
-               sgt = drm_prime_pages_to_sg(etnaviv_obj->pages, npages);
+               sgt = drm_prime_pages_to_sg(etnaviv_obj->base.dev,
+                                           etnaviv_obj->pages, npages);
                if (IS_ERR(sgt)) {
                        dev_err(dev->dev, "failed to allocate sgt: %ld\n",
                                PTR_ERR(sgt));

diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index 6d9e5c3..4aa3426 100644 (file)
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -19,7 +19,7 @@ struct sg_table *etnaviv_gem_prime_get_sg_table(struct drm_gem_object *obj)
        if (WARN_ON(!etnaviv_obj->pages))  /* should have already pinned! */
                return ERR_PTR(-EINVAL);
 
-       return drm_prime_pages_to_sg(etnaviv_obj->pages, npages);
+       return drm_prime_pages_to_sg(obj->dev, etnaviv_obj->pages, npages);
 }
 
 void *etnaviv_gem_prime_vmap(struct drm_gem_object *obj)

diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index b2f4915..b4553ca 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -126,7 +126,7 @@ static struct page **get_pages(struct drm_gem_object *obj)
 
                msm_obj->pages = p;
 
-               msm_obj->sgt = drm_prime_pages_to_sg(p, npages);
+               msm_obj->sgt = drm_prime_pages_to_sg(obj->dev, p, npages);
                if (IS_ERR(msm_obj->sgt)) {
                        void *ptr = ERR_CAST(msm_obj->sgt);
 

diff --git a/drivers/gpu/drm/msm/msm_gem_prime.c b/drivers/gpu/drm/msm/msm_gem_prime.c
index d7c8948..515ef80 100644 (file)
--- a/drivers/gpu/drm/msm/msm_gem_prime.c
+++ b/drivers/gpu/drm/msm/msm_gem_prime.c
@@ -19,7 +19,7 @@ struct sg_table *msm_gem_prime_get_sg_table(struct drm_gem_object *obj)
        if (WARN_ON(!msm_obj->pages))  /* should have already pinned! */
                return NULL;
 
-       return drm_prime_pages_to_sg(msm_obj->pages, npages);
+       return drm_prime_pages_to_sg(obj->dev, msm_obj->pages, npages);
 }
 
 void *msm_gem_prime_vmap(struct drm_gem_object *obj)

diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c b/drivers/gpu/drm/nouveau/nouveau_prime.c
index bae6a3e..7766b81 100644 (file)
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -32,7 +32,7 @@ struct sg_table *nouveau_gem_prime_get_sg_table(struct drm_gem_object *obj)
        struct nouveau_bo *nvbo = nouveau_gem_object(obj);
        int npages = nvbo->bo.num_pages;
 
-       return drm_prime_pages_to_sg(nvbo->bo.ttm->pages, npages);
+       return drm_prime_pages_to_sg(obj->dev, nvbo->bo.ttm->pages, npages);
 }
 
 void *nouveau_gem_prime_vmap(struct drm_gem_object *obj)

diff --git a/drivers/gpu/drm/radeon/radeon_prime.c b/drivers/gpu/drm/radeon/radeon_prime.c
index d6d9c8b..b9de0e5 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_prime.c
+++ b/drivers/gpu/drm/radeon/radeon_prime.c
@@ -36,7 +36,7 @@ struct sg_table *radeon_gem_prime_get_sg_table(struct drm_gem_object *obj)
        struct radeon_bo *bo = gem_to_radeon_bo(obj);
        int npages = bo->tbo.num_pages;
 
-       return drm_prime_pages_to_sg(bo->tbo.ttm->pages, npages);
+       return drm_prime_pages_to_sg(obj->dev, bo->tbo.ttm->pages, npages);
 }
 
 void *radeon_gem_prime_vmap(struct drm_gem_object *obj)

diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index b9275ba..0055d86 100644 (file)
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -85,7 +85,8 @@ static int rockchip_gem_get_pages(struct rockchip_gem_object *rk_obj)
 
        rk_obj->num_pages = rk_obj->base.size >> PAGE_SHIFT;
 
-       rk_obj->sgt = drm_prime_pages_to_sg(rk_obj->pages, rk_obj->num_pages);
+       rk_obj->sgt = drm_prime_pages_to_sg(rk_obj->base.dev,
+                                           rk_obj->pages, rk_obj->num_pages);
        if (IS_ERR(rk_obj->sgt)) {
                ret = PTR_ERR(rk_obj->sgt);
                goto err_put_pages;
@@ -442,7 +443,7 @@ struct sg_table *rockchip_gem_prime_get_sg_table(struct drm_gem_object *obj)
        int ret;
 
        if (rk_obj->pages)
-               return drm_prime_pages_to_sg(rk_obj->pages, rk_obj->num_pages);
+               return drm_prime_pages_to_sg(obj->dev, rk_obj->pages, rk_obj->num_pages);
 
        sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
        if (!sgt)

diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index 723df14..47e2935 100644 (file)
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -284,7 +284,7 @@ static int tegra_bo_get_pages(struct drm_device *drm, struct tegra_bo *bo)
 
        bo->num_pages = bo->gem.size >> PAGE_SHIFT;
 
-       bo->sgt = drm_prime_pages_to_sg(bo->pages, bo->num_pages);
+       bo->sgt = drm_prime_pages_to_sg(bo->gem.dev, bo->pages, bo->num_pages);
        if (IS_ERR(bo->sgt)) {
                err = PTR_ERR(bo->sgt);
                goto put_pages;

diff --git a/drivers/gpu/drm/vgem/vgem_drv.c b/drivers/gpu/drm/vgem/vgem_drv.c
index 313339b..15dd41e 100644 (file)
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -321,7 +321,7 @@ static struct sg_table *vgem_prime_get_sg_table(struct drm_gem_object *obj)
 {
        struct drm_vgem_gem_object *bo = to_vgem_bo(obj);
 
-       return drm_prime_pages_to_sg(bo->pages, bo->base.size >> PAGE_SHIFT);
+       return drm_prime_pages_to_sg(obj->dev, bo->pages, bo->base.size >> PAGE_SHIFT);
 }
 
 static struct drm_gem_object* vgem_prime_import(struct drm_device *dev,

diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 39ff95b..aed7510 100644 (file)
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -179,7 +179,8 @@ struct sg_table *xen_drm_front_gem_get_sg_table(struct drm_gem_object *gem_obj)
        if (!xen_obj->pages)
                return ERR_PTR(-ENOMEM);
 
-       return drm_prime_pages_to_sg(xen_obj->pages, xen_obj->num_pages);
+       return drm_prime_pages_to_sg(gem_obj->dev,
+                                    xen_obj->pages, xen_obj->num_pages);
 }
 
 struct drm_gem_object *

diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 9af7422..bf141e7 100644 (file)
--- a/include/drm/drm_prime.h
+++ b/include/drm/drm_prime.h
@@ -88,7 +88,8 @@ void drm_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr);
 int drm_gem_prime_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
 int drm_gem_dmabuf_mmap(struct dma_buf *dma_buf, struct vm_area_struct *vma);
 
-struct sg_table *drm_prime_pages_to_sg(struct page **pages, unsigned int nr_pages);
+struct sg_table *drm_prime_pages_to_sg(struct drm_device *dev,
+                                      struct page **pages, unsigned int nr_pages);
 struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj,
                                     int flags);