drm: use anon-inode instead of relying on cdevs
DRM drivers share a common address_space across all character-devices of a
single DRM device. This allows simple buffer eviction and mapping-control.
However, DRM core currently waits for the first ->open() on any char-dev
to mark the underlying inode as backing inode of the device. This delayed
initialization causes ugly conditions all over the place:
if (dev->dev_mapping)
do_sth();
To avoid delayed initialization and to stop reusing the inode of the
char-dev, we allocate an anonymous inode for each DRM device and reset
filp->f_mapping to it on ->open().
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
diff --git a/drivers/gpu/drm/ast/ast_ttm.c b/drivers/gpu/drm/ast/ast_ttm.c
index 4ea9b17..2b49153 100644
--- a/drivers/gpu/drm/ast/ast_ttm.c
+++ b/drivers/gpu/drm/ast/ast_ttm.c
@@ -324,7 +324,7 @@
}
astbo->bo.bdev = &ast->ttm.bdev;
- astbo->bo.bdev->dev_mapping = dev->dev_mapping;
+ astbo->bo.bdev->dev_mapping = dev->anon_inode->i_mapping;
ast_ttm_placement(astbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
diff --git a/drivers/gpu/drm/bochs/bochs_mm.c b/drivers/gpu/drm/bochs/bochs_mm.c
index ce68587..2d8546d 100644
--- a/drivers/gpu/drm/bochs/bochs_mm.c
+++ b/drivers/gpu/drm/bochs/bochs_mm.c
@@ -359,7 +359,7 @@
}
bochsbo->bo.bdev = &bochs->ttm.bdev;
- bochsbo->bo.bdev->dev_mapping = dev->dev_mapping;
+ bochsbo->bo.bdev->dev_mapping = dev->anon_inode->i_mapping;
bochs_ttm_placement(bochsbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
diff --git a/drivers/gpu/drm/cirrus/cirrus_ttm.c b/drivers/gpu/drm/cirrus/cirrus_ttm.c
index 8b37c25..efcbd70 100644
--- a/drivers/gpu/drm/cirrus/cirrus_ttm.c
+++ b/drivers/gpu/drm/cirrus/cirrus_ttm.c
@@ -329,7 +329,7 @@
}
cirrusbo->bo.bdev = &cirrus->ttm.bdev;
- cirrusbo->bo.bdev->dev_mapping = dev->dev_mapping;
+ cirrusbo->bo.bdev->dev_mapping = dev->anon_inode->i_mapping;
cirrus_ttm_placement(cirrusbo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 7f2af9a..147a84d 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -84,8 +84,6 @@
struct drm_minor *minor;
int retcode = 0;
int need_setup = 0;
- struct address_space *old_mapping;
- struct address_space *old_imapping;
minor = idr_find(&drm_minors_idr, minor_id);
if (!minor)
@@ -99,16 +97,9 @@
if (!dev->open_count++)
need_setup = 1;
- mutex_lock(&dev->struct_mutex);
- old_imapping = inode->i_mapping;
- old_mapping = dev->dev_mapping;
- if (old_mapping == NULL)
- dev->dev_mapping = &inode->i_data;
- /* ihold ensures nobody can remove inode with our i_data */
- ihold(container_of(dev->dev_mapping, struct inode, i_data));
- inode->i_mapping = dev->dev_mapping;
- filp->f_mapping = dev->dev_mapping;
- mutex_unlock(&dev->struct_mutex);
+
+ /* share address_space across all char-devs of a single device */
+ filp->f_mapping = dev->anon_inode->i_mapping;
retcode = drm_open_helper(inode, filp, dev);
if (retcode)
@@ -121,12 +112,6 @@
return 0;
err_undo:
- mutex_lock(&dev->struct_mutex);
- filp->f_mapping = old_imapping;
- inode->i_mapping = old_imapping;
- iput(container_of(dev->dev_mapping, struct inode, i_data));
- dev->dev_mapping = old_mapping;
- mutex_unlock(&dev->struct_mutex);
dev->open_count--;
return retcode;
}
@@ -434,7 +419,6 @@
drm_legacy_dma_takedown(dev);
- dev->dev_mapping = NULL;
mutex_unlock(&dev->struct_mutex);
drm_legacy_dev_reinit(dev);
@@ -549,9 +533,6 @@
}
}
- BUG_ON(dev->dev_mapping == NULL);
- iput(container_of(dev->dev_mapping, struct inode, i_data));
-
/* drop the reference held my the file priv */
if (file_priv->master)
drm_master_put(&file_priv->master);
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index f2903d7..04c25ce 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -526,8 +526,15 @@
mutex_init(&dev->struct_mutex);
mutex_init(&dev->ctxlist_mutex);
- if (drm_ht_create(&dev->map_hash, 12))
+ dev->anon_inode = drm_fs_inode_new();
+ if (IS_ERR(dev->anon_inode)) {
+ ret = PTR_ERR(dev->anon_inode);
+ DRM_ERROR("Cannot allocate anonymous inode: %d\n", ret);
goto err_free;
+ }
+
+ if (drm_ht_create(&dev->map_hash, 12))
+ goto err_inode;
ret = drm_ctxbitmap_init(dev);
if (ret) {
@@ -549,6 +556,8 @@
drm_ctxbitmap_cleanup(dev);
err_ht:
drm_ht_remove(&dev->map_hash);
+err_inode:
+ drm_fs_inode_free(dev->anon_inode);
err_free:
kfree(dev);
return NULL;
@@ -576,6 +585,7 @@
drm_ctxbitmap_cleanup(dev);
drm_ht_remove(&dev->map_hash);
+ drm_fs_inode_free(dev->anon_inode);
kfree(dev->devname);
kfree(dev);
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 3618bb0..928e15b 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -1508,7 +1508,8 @@
if (!obj->fault_mappable)
return;
- drm_vma_node_unmap(&obj->base.vma_node, obj->base.dev->dev_mapping);
+ drm_vma_node_unmap(&obj->base.vma_node,
+ obj->base.dev->anon_inode->i_mapping);
obj->fault_mappable = false;
}
diff --git a/drivers/gpu/drm/mgag200/mgag200_ttm.c b/drivers/gpu/drm/mgag200/mgag200_ttm.c
index adb5166..c1c2cb6 100644
--- a/drivers/gpu/drm/mgag200/mgag200_ttm.c
+++ b/drivers/gpu/drm/mgag200/mgag200_ttm.c
@@ -324,7 +324,7 @@
}
mgabo->bo.bdev = &mdev->ttm.bdev;
- mgabo->bo.bdev->dev_mapping = dev->dev_mapping;
+ mgabo->bo.bdev->dev_mapping = dev->anon_inode->i_mapping;
mgag200_ttm_placement(mgabo, TTM_PL_FLAG_VRAM | TTM_PL_FLAG_SYSTEM);
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index 27c3fd8..5b193b8 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -228,7 +228,7 @@
struct nouveau_bo *nvbo = NULL;
int ret = 0;
- drm->ttm.bdev.dev_mapping = drm->dev->dev_mapping;
+ drm->ttm.bdev.dev_mapping = drm->dev->anon_inode->i_mapping;
if (!pfb->memtype_valid(pfb, req->info.tile_flags)) {
NV_ERROR(cli, "bad page flags: 0x%08x\n", req->info.tile_flags);
diff --git a/drivers/gpu/drm/omapdrm/omap_gem.c b/drivers/gpu/drm/omapdrm/omap_gem.c
index 5aec3e8..c8d9727 100644
--- a/drivers/gpu/drm/omapdrm/omap_gem.c
+++ b/drivers/gpu/drm/omapdrm/omap_gem.c
@@ -153,24 +153,24 @@
static void evict_entry(struct drm_gem_object *obj,
enum tiler_fmt fmt, struct usergart_entry *entry)
{
- if (obj->dev->dev_mapping) {
- struct omap_gem_object *omap_obj = to_omap_bo(obj);
- int n = usergart[fmt].height;
- size_t size = PAGE_SIZE * n;
- loff_t off = mmap_offset(obj) +
- (entry->obj_pgoff << PAGE_SHIFT);
- const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
- if (m > 1) {
- int i;
- /* if stride > than PAGE_SIZE then sparse mapping: */
- for (i = n; i > 0; i--) {
- unmap_mapping_range(obj->dev->dev_mapping,
- off, PAGE_SIZE, 1);
- off += PAGE_SIZE * m;
- }
- } else {
- unmap_mapping_range(obj->dev->dev_mapping, off, size, 1);
+ struct omap_gem_object *omap_obj = to_omap_bo(obj);
+ int n = usergart[fmt].height;
+ size_t size = PAGE_SIZE * n;
+ loff_t off = mmap_offset(obj) +
+ (entry->obj_pgoff << PAGE_SHIFT);
+ const int m = 1 + ((omap_obj->width << fmt) / PAGE_SIZE);
+
+ if (m > 1) {
+ int i;
+ /* if stride > than PAGE_SIZE then sparse mapping: */
+ for (i = n; i > 0; i--) {
+ unmap_mapping_range(obj->dev->anon_inode->i_mapping,
+ off, PAGE_SIZE, 1);
+ off += PAGE_SIZE * m;
}
+ } else {
+ unmap_mapping_range(obj->dev->anon_inode->i_mapping,
+ off, size, 1);
}
entry->obj = NULL;
diff --git a/drivers/gpu/drm/qxl/qxl_object.c b/drivers/gpu/drm/qxl/qxl_object.c
index 8691c76..7e20c21 100644
--- a/drivers/gpu/drm/qxl/qxl_object.c
+++ b/drivers/gpu/drm/qxl/qxl_object.c
@@ -82,8 +82,7 @@
enum ttm_bo_type type;
int r;
- if (unlikely(qdev->mman.bdev.dev_mapping == NULL))
- qdev->mman.bdev.dev_mapping = qdev->ddev->dev_mapping;
+ qdev->mman.bdev.dev_mapping = qdev->ddev->anon_inode->i_mapping;
if (kernel)
type = ttm_bo_type_kernel;
else
diff --git a/drivers/gpu/drm/qxl/qxl_ttm.c b/drivers/gpu/drm/qxl/qxl_ttm.c
index c7e7e65..78cbc40 100644
--- a/drivers/gpu/drm/qxl/qxl_ttm.c
+++ b/drivers/gpu/drm/qxl/qxl_ttm.c
@@ -518,8 +518,7 @@
((unsigned)num_io_pages * PAGE_SIZE) / (1024 * 1024));
DRM_INFO("qxl: %uM of Surface memory size\n",
(unsigned)qdev->surfaceram_size / (1024 * 1024));
- if (unlikely(qdev->mman.bdev.dev_mapping == NULL))
- qdev->mman.bdev.dev_mapping = qdev->ddev->dev_mapping;
+ qdev->mman.bdev.dev_mapping = qdev->ddev->anon_inode->i_mapping;
r = qxl_ttm_debugfs_init(qdev);
if (r) {
DRM_ERROR("Failed to init debugfs\n");
diff --git a/drivers/gpu/drm/radeon/radeon_object.c b/drivers/gpu/drm/radeon/radeon_object.c
index ca79431..6a7f3c6 100644
--- a/drivers/gpu/drm/radeon/radeon_object.c
+++ b/drivers/gpu/drm/radeon/radeon_object.c
@@ -145,7 +145,7 @@
size = ALIGN(size, PAGE_SIZE);
- rdev->mman.bdev.dev_mapping = rdev->ddev->dev_mapping;
+ rdev->mman.bdev.dev_mapping = rdev->ddev->anon_inode->i_mapping;
if (kernel) {
type = ttm_bo_type_kernel;
} else if (sg) {
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c
index 60dfce8..4663fbc 100644
--- a/drivers/gpu/drm/radeon/radeon_ttm.c
+++ b/drivers/gpu/drm/radeon/radeon_ttm.c
@@ -745,7 +745,7 @@
}
DRM_INFO("radeon: %uM of GTT memory ready.\n",
(unsigned)(rdev->mc.gtt_size / (1024 * 1024)));
- rdev->mman.bdev.dev_mapping = rdev->ddev->dev_mapping;
+ rdev->mman.bdev.dev_mapping = rdev->ddev->anon_inode->i_mapping;
r = radeon_ttm_debugfs_init(rdev);
if (r) {
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 0083cbf..df4b03e 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -969,7 +969,7 @@
goto out_no_shman;
file_priv->driver_priv = vmw_fp;
- dev_priv->bdev.dev_mapping = dev->dev_mapping;
+ dev_priv->bdev.dev_mapping = dev->anon_inode->i_mapping;
return 0;
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 04a7f31..3227b71 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1183,7 +1183,7 @@
struct drm_sg_mem *sg; /**< Scatter gather memory */
unsigned int num_crtcs; /**< Number of CRTCs on this device */
void *dev_private; /**< device private data */
- struct address_space *dev_mapping;
+ struct inode *anon_inode;
struct drm_sigdata sigdata; /**< For block_all_signals */
sigset_t sigmask;
