Re: [PATCH 1/2] drm: allow limiting the scatter list size.
From: Christian König
Date: Tue Aug 18 2020 - 03:58:15 EST
Am 18.08.20 um 09:48 schrieb Gerd Hoffmann:
Add max_segment argument to drm_prime_pages_to_sg(). When set pass it
through to the __sg_alloc_table_from_pages() call, otherwise use
SCATTERLIST_MAX_SEGMENT.
Also add max_segment field to gem objects and pass it to
drm_prime_pages_to_sg() calls in drivers and helpers.
Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
I'm missing an explanation why this should be useful (it certainly is).
And the maximum segment size seems misplaced in the GEM object. This is
usually a property of the device or even completely constant.
Christian.
---
include/drm/drm_gem.h | 8 ++++++++
include/drm/drm_prime.h | 3 ++-
drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 3 ++-
drivers/gpu/drm/drm_gem_shmem_helper.c | 3 ++-
drivers/gpu/drm/drm_prime.c | 10 +++++++---
drivers/gpu/drm/etnaviv/etnaviv_gem.c | 3 ++-
drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c | 3 ++-
drivers/gpu/drm/msm/msm_gem.c | 3 ++-
drivers/gpu/drm/msm/msm_gem_prime.c | 3 ++-
drivers/gpu/drm/nouveau/nouveau_prime.c | 3 ++-
drivers/gpu/drm/radeon/radeon_prime.c | 3 ++-
drivers/gpu/drm/rockchip/rockchip_drm_gem.c | 6 ++++--
drivers/gpu/drm/tegra/gem.c | 3 ++-
drivers/gpu/drm/vgem/vgem_drv.c | 3 ++-
drivers/gpu/drm/xen/xen_drm_front_gem.c | 3 ++-
15 files changed, 43 insertions(+), 17 deletions(-)
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 337a48321705..dea5e92e745b 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -241,6 +241,14 @@ struct drm_gem_object {
*/
size_t size;
+ /**
+ * @max_segment:
+ *
+ * Max size for scatter list segments. When unset the default
+ * (SCATTERLIST_MAX_SEGMENT) is used.
+ */
+ size_t max_segment;
+
/**
* @name:
*
diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
index 9af7422b44cf..2c3689435cb4 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 page **pages, unsigned int nr_pages,
+ size_t max_segment);
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..5e8a9760b33f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -303,7 +303,8 @@ 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,
- bo->tbo.num_pages);
+ bo->tbo.num_pages,
+ obj->max_segment);
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..cfb979d808fd 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -656,7 +656,8 @@ 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(shmem->pages, obj->size >> PAGE_SHIFT,
+ obj->max_segment);
}
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..27c783fd6633 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -802,7 +802,8 @@ 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 page **pages, unsigned int nr_pages,
+ size_t max_segment)
{
struct sg_table *sg = NULL;
int ret;
@@ -813,8 +814,11 @@ 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 (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..e5b6e7996f80 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->pages, npages,
+ etnaviv_obj->base.max_segment);
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..f327676450bd 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -19,7 +19,8 @@ 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(etnaviv_obj->pages, npages,
+ obj->max_segment);
}
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..f805419bb84a 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -126,7 +126,8 @@ 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(p, npages,
+ obj->max_segment);
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..a5a412564c7f 100644
--- a/drivers/gpu/drm/msm/msm_gem_prime.c
+++ b/drivers/gpu/drm/msm/msm_gem_prime.c
@@ -19,7 +19,8 @@ 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(msm_obj->pages, npages,
+ obj->max_segment);
}
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..56a2e916d51a 100644
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -32,7 +32,8 @@ 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(nvbo->bo.ttm->pages, npages,
+ obj->max_segment);
}
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..503e35625045 100644
--- a/drivers/gpu/drm/radeon/radeon_prime.c
+++ b/drivers/gpu/drm/radeon/radeon_prime.c
@@ -36,7 +36,8 @@ 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(bo->tbo.ttm->pages, npages,
+ obj->max_segment);
}
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..444657e03c16 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->pages, rk_obj->num_pages,
+ rk_obj->base.max_segment);
if (IS_ERR(rk_obj->sgt)) {
ret = PTR_ERR(rk_obj->sgt);
goto err_put_pages;
@@ -442,7 +443,8 @@ 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(rk_obj->pages, rk_obj->num_pages,
+ obj->max_segment);
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..8d98b02a8d21 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -284,7 +284,8 @@ 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->pages, bo->num_pages,
+ bo->gem.max_segment);
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..d25c93b5a2c1 100644
--- a/drivers/gpu/drm/vgem/vgem_drv.c
+++ b/drivers/gpu/drm/vgem/vgem_drv.c
@@ -321,7 +321,8 @@ 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(bo->pages, bo->base.size >> PAGE_SHIFT,
+ obj->max_segment);
}
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 f0b85e094111..362fe5311b1b 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(xen_obj->pages, xen_obj->num_pages,
+ gem_obj->max_segment);
}
struct drm_gem_object *