Re: [PATCH 2/5] drm/gem: Add a mountpoint parameter to drm_gem_object_init()

Christian König <christian.koenig@xxxxxxx> · Tue, 12 Mar 2024 09:59:26 +0100

Am 12.03.24 um 09:51 schrieb Tvrtko Ursulin:

Hi Maira,

On 11/03/2024 10:05, Maíra Canal wrote:
For some applications, such as using huge pages, we might want to have a
different mountpoint, for which we pass in mount flags that better match
our usecase.

Therefore, add a new parameter to drm_gem_object_init() that allow us to
define the tmpfs mountpoint where the GEM object will be created. If
this parameter is NULL, then we fallback to shmem_file_setup().

One strategy for reducing churn, and so the number of drivers this 
patch touches, could be to add a lower level drm_gem_object_init() 
(which takes vfsmount, call it __drm_gem_object_init(), or 
drm__gem_object_init_mnt(), and make drm_gem_object_init() call that 
one with a NULL argument.

I would even go a step further into the other direction. The shmem 
backed GEM object is just some special handling as far as I can see.

So I would rather suggest to rename all drm_gem_* function which only 
deal with the shmem backed GEM object into drm_gem_shmem_*.

Also the explanation why a different mount point helps with something 
isn't very satisfying.

Regards,
Christian.


Regards,

Tvrtko


Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Christian Gmeiner <christian.gmeiner@xxxxxxxxx>
Cc: Inki Dae <inki.dae@xxxxxxxxxxx>
Cc: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx>
Cc: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Cc: Alim Akhtar <alim.akhtar@xxxxxxxxxxx>
Cc: Patrik Jakobsson <patrik.r.jakobsson@xxxxxxxxx>
Cc: Sui Jingfeng <suijingfeng@xxxxxxxxxxx>
Cc: Chun-Kuang Hu <chunkuang.hu@xxxxxxxxxx>
Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
Cc: Matthias Brugger <matthias.bgg@xxxxxxxxx>
Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
Cc: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Cc: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>
Cc: Karol Herbst <kherbst@xxxxxxxxxx>
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: Danilo Krummrich <dakr@xxxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>
Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Cc: Sandy Huang <hjc@xxxxxxxxxxxxxx>
Cc: "Heiko Stübner" <heiko@xxxxxxxxx>
Cc: Andy Yan <andy.yan@xxxxxxxxxxxxxx>
Cc: Thierry Reding <thierry.reding@xxxxxxxxx>
Cc: Mikko Perttunen <mperttunen@xxxxxxxxxx>
Cc: Jonathan Hunter <jonathanh@xxxxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Huang Rui <ray.huang@xxxxxxx>
Cc: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
Cc: Karolina Stolarek <karolina.stolarek@xxxxxxxxx>
Cc: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
Signed-off-by: Maíra Canal <mcanal@xxxxxxxxxx>
---
  drivers/gpu/drm/armada/armada_gem.c           |  2 +-
  drivers/gpu/drm/drm_gem.c                     | 12 ++++++++++--
  drivers/gpu/drm/drm_gem_dma_helper.c          |  2 +-
  drivers/gpu/drm/drm_gem_shmem_helper.c        |  2 +-
  drivers/gpu/drm/drm_gem_vram_helper.c         |  2 +-
  drivers/gpu/drm/etnaviv/etnaviv_gem.c         |  2 +-
  drivers/gpu/drm/exynos/exynos_drm_gem.c       |  2 +-
  drivers/gpu/drm/gma500/gem.c                  |  2 +-
  drivers/gpu/drm/loongson/lsdc_ttm.c           |  2 +-
  drivers/gpu/drm/mediatek/mtk_drm_gem.c        |  2 +-
  drivers/gpu/drm/msm/msm_gem.c                 |  2 +-
  drivers/gpu/drm/nouveau/nouveau_gem.c         |  2 +-
  drivers/gpu/drm/nouveau/nouveau_prime.c       |  2 +-
  drivers/gpu/drm/omapdrm/omap_gem.c            |  2 +-
  drivers/gpu/drm/qxl/qxl_object.c              |  2 +-
  drivers/gpu/drm/rockchip/rockchip_drm_gem.c   |  2 +-
  drivers/gpu/drm/tegra/gem.c                   |  2 +-
  drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c |  2 +-
  drivers/gpu/drm/xen/xen_drm_front_gem.c       |  2 +-
  include/drm/drm_gem.h                         |  3 ++-
  20 files changed, 30 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/armada/armada_gem.c 
b/drivers/gpu/drm/armada/armada_gem.c
index 26d10065d534..36a25e667341 100644
--- a/drivers/gpu/drm/armada/armada_gem.c
+++ b/drivers/gpu/drm/armada/armada_gem.c
@@ -226,7 +226,7 @@ static struct armada_gem_object 
*armada_gem_alloc_object(struct drm_device *dev,

      obj->obj.funcs = &armada_gem_object_funcs;

-    if (drm_gem_object_init(dev, &obj->obj, size)) {
+    if (drm_gem_object_init(dev, &obj->obj, size, NULL)) {
          kfree(obj);
          return NULL;
      }
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 44a948b80ee1..ddd8777fcda5 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -118,18 +118,26 @@ drm_gem_init(struct drm_device *dev)
   * @dev: drm_device the object should be initialized for
   * @obj: drm_gem_object to initialize
   * @size: object size
+ * @gemfs: tmpfs mount where the GEM object will be created. If 
NULL, use
+ * the usual tmpfs mountpoint (`shm_mnt`).
   *
   * Initialize an already allocated GEM object of the specified size 
with
   * shmfs backing store.
   */
  int drm_gem_object_init(struct drm_device *dev,
-            struct drm_gem_object *obj, size_t size)
+            struct drm_gem_object *obj, size_t size,
+            struct vfsmount *gemfs)
  {
      struct file *filp;

      drm_gem_private_object_init(dev, obj, size);

-    filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
+    if (gemfs)
+        filp = shmem_file_setup_with_mnt(gemfs, "drm mm object", size,
+                         VM_NORESERVE);
+    else
+        filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
+
      if (IS_ERR(filp))
          return PTR_ERR(filp);

diff --git a/drivers/gpu/drm/drm_gem_dma_helper.c 
b/drivers/gpu/drm/drm_gem_dma_helper.c
index 870b90b78bc4..9ada5ac85dd6 100644
--- a/drivers/gpu/drm/drm_gem_dma_helper.c
+++ b/drivers/gpu/drm/drm_gem_dma_helper.c
@@ -95,7 +95,7 @@ __drm_gem_dma_create(struct drm_device *drm, size_t 
size, bool private)
          /* Always use writecombine for dma-buf mappings */
          dma_obj->map_noncoherent = false;
      } else {
-        ret = drm_gem_object_init(drm, gem_obj, size);
+        ret = drm_gem_object_init(drm, gem_obj, size, NULL);
      }
      if (ret)
          goto error;
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c 
b/drivers/gpu/drm/drm_gem_shmem_helper.c
index e435f986cd13..15635b330ca8 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -77,7 +77,7 @@ __drm_gem_shmem_create(struct drm_device *dev, 
size_t size, bool private)
          drm_gem_private_object_init(dev, obj, size);
          shmem->map_wc = false; /* dma-buf mappings use always 
writecombine */
      } else {
-        ret = drm_gem_object_init(dev, obj, size);
+        ret = drm_gem_object_init(dev, obj, size, NULL);
      }
      if (ret) {
          drm_gem_private_object_fini(obj);
diff --git a/drivers/gpu/drm/drm_gem_vram_helper.c 
b/drivers/gpu/drm/drm_gem_vram_helper.c
index 75f2eaf0d5b6..90649899dbef 100644
--- a/drivers/gpu/drm/drm_gem_vram_helper.c
+++ b/drivers/gpu/drm/drm_gem_vram_helper.c
@@ -210,7 +210,7 @@ struct drm_gem_vram_object 
*drm_gem_vram_create(struct drm_device *dev,
      if (!gem->funcs)
          gem->funcs = &drm_gem_vram_object_funcs;

-    ret = drm_gem_object_init(dev, gem, size);
+    ret = drm_gem_object_init(dev, gem, size, NULL);
      if (ret) {
          kfree(gbo);
          return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c 
b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index 71a6d2b1c80f..aa4b61c48b7f 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -596,7 +596,7 @@ int etnaviv_gem_new_handle(struct drm_device 
*dev, struct drm_file *file,

      lockdep_set_class(&to_etnaviv_bo(obj)->lock, 
&etnaviv_shm_lock_class);

-    ret = drm_gem_object_init(dev, obj, size);
+    ret = drm_gem_object_init(dev, obj, size, NULL);
      if (ret)
          goto fail;

diff --git a/drivers/gpu/drm/exynos/exynos_drm_gem.c 
b/drivers/gpu/drm/exynos/exynos_drm_gem.c
index 638ca96830e9..c50c0d12246e 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_gem.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_gem.c
@@ -160,7 +160,7 @@ static struct exynos_drm_gem 
*exynos_drm_gem_init(struct drm_device *dev,

      obj->funcs = &exynos_drm_gem_object_funcs;

-    ret = drm_gem_object_init(dev, obj, size);
+    ret = drm_gem_object_init(dev, obj, size, NULL);
      if (ret < 0) {
          DRM_DEV_ERROR(dev->dev, "failed to initialize gem object\n");
          kfree(exynos_gem);
diff --git a/drivers/gpu/drm/gma500/gem.c b/drivers/gpu/drm/gma500/gem.c
index 4b7627a72637..315e085dc9ee 100644
--- a/drivers/gpu/drm/gma500/gem.c
+++ b/drivers/gpu/drm/gma500/gem.c
@@ -169,7 +169,7 @@ psb_gem_create(struct drm_device *dev, u64 size, 
const char *name, bool stolen,
      if (stolen) {
          drm_gem_private_object_init(dev, obj, size);
      } else {
-        ret = drm_gem_object_init(dev, obj, size);
+        ret = drm_gem_object_init(dev, obj, size, NULL);
          if (ret)
              goto err_release_resource;

diff --git a/drivers/gpu/drm/loongson/lsdc_ttm.c 
b/drivers/gpu/drm/loongson/lsdc_ttm.c
index 465f622ac05d..d392ea66d72e 100644
--- a/drivers/gpu/drm/loongson/lsdc_ttm.c
+++ b/drivers/gpu/drm/loongson/lsdc_ttm.c
@@ -458,7 +458,7 @@ struct lsdc_bo *lsdc_bo_create(struct drm_device 
*ddev,

      size = ALIGN(size, PAGE_SIZE);

-    ret = drm_gem_object_init(ddev, &tbo->base, size);
+    ret = drm_gem_object_init(ddev, &tbo->base, size, NULL);
      if (ret) {
          kfree(lbo);
          return ERR_PTR(ret);
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c 
b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index 4f2e3feabc0f..261d386921dc 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -44,7 +44,7 @@ static struct mtk_drm_gem_obj 
*mtk_drm_gem_init(struct drm_device *dev,

      mtk_gem_obj->base.funcs = &mtk_drm_gem_object_funcs;

-    ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
+    ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size, NULL);
      if (ret < 0) {
          DRM_ERROR("failed to initialize gem object\n");
          kfree(mtk_gem_obj);
diff --git a/drivers/gpu/drm/msm/msm_gem.c 
b/drivers/gpu/drm/msm/msm_gem.c
index 175ee4ab8a6f..6fe17cf28ef6 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -1222,7 +1222,7 @@ struct drm_gem_object *msm_gem_new(struct 
drm_device *dev, uint32_t size, uint32

          vma->iova = physaddr(obj);
      } else {
-        ret = drm_gem_object_init(dev, obj, size);
+        ret = drm_gem_object_init(dev, obj, size, NULL);
          if (ret)
              goto fail;
          /*
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c 
b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 49c2bcbef129..434325fa8752 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -262,7 +262,7 @@ nouveau_gem_new(struct nouveau_cli *cli, u64 
size, int align, uint32_t domain,

      /* Initialize the embedded gem-object. We return a single 
gem-reference
       * to the caller, instead of a normal nouveau_bo ttm reference. */
-    ret = drm_gem_object_init(drm->dev, &nvbo->bo.base, size);
+    ret = drm_gem_object_init(drm->dev, &nvbo->bo.base, size, NULL);
      if (ret) {
          drm_gem_object_release(&nvbo->bo.base);
          kfree(nvbo);
diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c 
b/drivers/gpu/drm/nouveau/nouveau_prime.c
index 1b2ff0c40fc1..c9b3572df555 100644
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -62,7 +62,7 @@ struct drm_gem_object 
*nouveau_gem_prime_import_sg_table(struct drm_device *dev,

      /* Initialize the embedded gem-object. We return a single 
gem-reference
       * to the caller, instead of a normal nouveau_bo ttm reference. */
-    ret = drm_gem_object_init(dev, &nvbo->bo.base, size);
+    ret = drm_gem_object_init(dev, &nvbo->bo.base, size, NULL);
      if (ret) {
          nouveau_bo_ref(NULL, &nvbo);
          obj = ERR_PTR(-ENOMEM);
diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c 
b/drivers/gpu/drm/omapdrm/omap_gem.c
index 3421e8389222..53b4ec64c7b0 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -1352,7 +1352,7 @@ struct drm_gem_object *omap_gem_new(struct 
drm_device *dev,
      if (!(flags & OMAP_BO_MEM_SHMEM)) {
          drm_gem_private_object_init(dev, obj, size);
      } else {
-        ret = drm_gem_object_init(dev, obj, size);
+        ret = drm_gem_object_init(dev, obj, size, NULL);
          if (ret)
              goto err_free;

diff --git a/drivers/gpu/drm/qxl/qxl_object.c 
b/drivers/gpu/drm/qxl/qxl_object.c
index 1e46b0a6e478..45d7abe26ebd 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -123,7 +123,7 @@ int qxl_bo_create(struct qxl_device *qdev, 
unsigned long size,
      if (bo == NULL)
          return -ENOMEM;
      size = roundup(size, PAGE_SIZE);
-    r = drm_gem_object_init(&qdev->ddev, &bo->tbo.base, size);
+    r = drm_gem_object_init(&qdev->ddev, &bo->tbo.base, size, NULL);
      if (unlikely(r)) {
          kfree(bo);
          return r;
diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c 
b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
index 93ed841f5dce..daba285bd78f 100644
--- a/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
+++ b/drivers/gpu/drm/rockchip/rockchip_drm_gem.c
@@ -295,7 +295,7 @@ static struct rockchip_gem_object *

      obj->funcs = &rockchip_gem_object_funcs;

-    drm_gem_object_init(drm, obj, size);
+    drm_gem_object_init(drm, obj, size, NULL);

      return rk_obj;
  }
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index b4eb030ea961..63f10d5a57ba 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -311,7 +311,7 @@ static struct tegra_bo 
*tegra_bo_alloc_object(struct drm_device *drm,
      host1x_bo_init(&bo->base, &tegra_bo_ops);
      size = round_up(size, PAGE_SIZE);

-    err = drm_gem_object_init(drm, &bo->gem, size);
+    err = drm_gem_object_init(drm, &bo->gem, size, NULL);
      if (err < 0)
          goto free;

diff --git a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c 
b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
index 7b7c1fa805fc..a9bf7d5a887c 100644
--- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
+++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
@@ -61,7 +61,7 @@ struct ttm_buffer_object *ttm_bo_kunit_init(struct 
kunit *test,
      KUNIT_ASSERT_NOT_NULL(test, bo);

      bo->base = gem_obj;
-    err = drm_gem_object_init(devs->drm, &bo->base, size);
+    err = drm_gem_object_init(devs->drm, &bo->base, size, NULL);
      KUNIT_ASSERT_EQ(test, err, 0);

      bo->bdev = devs->ttm_dev;
diff --git a/drivers/gpu/drm/xen/xen_drm_front_gem.c 
b/drivers/gpu/drm/xen/xen_drm_front_gem.c
index 3ad2b4cfd1f0..1b36c958340b 100644
--- a/drivers/gpu/drm/xen/xen_drm_front_gem.c
+++ b/drivers/gpu/drm/xen/xen_drm_front_gem.c
@@ -122,7 +122,7 @@ static struct xen_gem_object 
*gem_create_obj(struct drm_device *dev,

      xen_obj->base.funcs = &xen_drm_front_gem_object_funcs;

-    ret = drm_gem_object_init(dev, &xen_obj->base, size);
+    ret = drm_gem_object_init(dev, &xen_obj->base, size, NULL);
      if (ret < 0) {
          kfree(xen_obj);
          return ERR_PTR(ret);
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 2ebec3984cd4..c75611ae8f93 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -471,7 +471,8 @@ struct drm_gem_object {
  void drm_gem_object_release(struct drm_gem_object *obj);
  void drm_gem_object_free(struct kref *kref);
  int drm_gem_object_init(struct drm_device *dev,
-            struct drm_gem_object *obj, size_t size);
+            struct drm_gem_object *obj, size_t size,
+            struct vfsmount *gemfs);
  void drm_gem_private_object_init(struct drm_device *dev,
                   struct drm_gem_object *obj, size_t size);
  void drm_gem_private_object_fini(struct drm_gem_object *obj);
--
2.43.0









