[PATCH v4 1/1] drm: allow limiting the scatter list size.

Gerd Hoffmann
2020-09-07T11:26:03Z

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>
---
include/drm/drm_prime.h | 3 ++-
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 3 ++-
drivers/gpu/drm/drm_gem_shmem_helper.c | 2 +-
drivers/gpu/drm/drm_prime.c | 13 ++++++++++---
drivers/gpu/drm/etnaviv/etnaviv_gem.c | 3 ++-
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 2 +-
drivers/gpu/drm/msm/msm_gem.c | 2 +-
drivers/gpu/drm/msm/msm_gem_prime.c | 2 +-
drivers/gpu/drm/nouveau/nouveau_prime.c | 2 +-
drivers/gpu/drm/radeon/radeon_prime.c | 2 +-
drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 5 +++--
drivers/gpu/drm/tegra/gem.c | 2 +-
drivers/gpu/drm/vgem/vgem_drv.c | 2 +-
drivers/gpu/drm/xen/xen_drm_front_gem.c | 3 ++-
14 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 9af7422b44cf..bf141e74a1c2 100644
--- 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);

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index 519ce4427fce..d7050ab95946 100644
--- 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 4b7cfbac4daa..0a952f27c184 100644
--- 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 1693aa7c14b5..8a6a3c99b7d8 100644
--- 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 f06e19e7be04..ea19f1d27275 100644
--- 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 6d9e5c3c4dd5..4aa3426a9ba4 100644
--- 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 b2f49152b4d4..b4553caaa196 100644
--- 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 d7c8948427fe..515ef80816a0 100644
--- 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 bae6a3eccee0..7766b810653f 100644
--- 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 b906e8fbd5f3..ea4c900e7c41 100644
--- 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 b9275ba7c5a5..77eeaf3439f6 100644
--- 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 723df142a981..47e2935b8c68 100644
--- 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 313339bbff90..15dd41e67de3 100644
--- 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 39ff95b75357..aed7510e2710 100644
--- 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 *
--
2.27.0