[PATCH 02/22] drm/i915: introduce simple gemfs

Matthew Auld
2017-08-15T18:11:55Z

Not a fully blown gemfs, just our very own tmpfs kernel mount. Doing so
moves us away from the shmemfs shm_mnt, and gives us the much needed
flexibility to do things like set our own mount options, namely huge=
which should allow us to enable the use of transparent-huge-pages for
our shmem backed objects.

v2: various improvements suggested by Joonas

v3: move gemfs instance to i915.mm and simplify now that we have
file_setup_with_mnt

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Hugh Dickins <hughd@google.com>
Cc: linux-mm@kvack.org
---
drivers/gpu/drm/i915/Makefile | 1 +
drivers/gpu/drm/i915/i915_drv.h | 3 ++
drivers/gpu/drm/i915/i915_gem.c | 34 +++++++++++++++-
drivers/gpu/drm/i915/i915_gemfs.c | 52 ++++++++++++++++++++++++
drivers/gpu/drm/i915/i915_gemfs.h | 34 ++++++++++++++++
drivers/gpu/drm/i915/selftests/mock_gem_device.c | 10 ++++-
6 files changed, 131 insertions(+), 3 deletions(-)
create mode 100644 drivers/gpu/drm/i915/i915_gemfs.c
create mode 100644 drivers/gpu/drm/i915/i915_gemfs.h

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 892f52b53060..24c3f672256b 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -47,6 +47,7 @@ i915-y += i915_cmd_parser.o \
i915_gem_tiling.o \
i915_gem_timeline.o \
i915_gem_userptr.o \
+ i915_gemfs.o \
i915_trace_points.o \
i915_vma.o \
intel_breadcrumbs.o \
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 6c25c8520c87..5d072317df14 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1467,6 +1467,9 @@ struct i915_gem_mm {
/** Usable portion of the GTT for GEM */
dma_addr_t stolen_base; /* limited to low memory (32-bit) */

+ /** tmpfs instance used for shmem backed objects */
+ struct vfsmount *gemfs;
+
/** PPGTT used for aliasing the PPGTT with the GTT */
struct i915_hw_ppgtt *aliasing_ppgtt;

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 5a3f3bb3f21d..03bff1a2ca13 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -35,6 +35,7 @@
#include "intel_drv.h"
#include "intel_frontbuffer.h"
#include "intel_mocs.h"
+#include "i915_gemfs.h"
#include <linux/dma-fence-array.h>
#include <linux/kthread.h>
#include <linux/reservation.h>
@@ -4279,6 +4280,25 @@ static const struct drm_i915_gem_object_ops i915_gem_object_ops = {
.pwrite = i915_gem_object_pwrite_gtt,
};

+static int i915_gem_object_create_shmem(struct drm_device *dev,
+ struct drm_gem_object *obj,
+ size_t size)
+{
+ struct drm_i915_private *i915 = to_i915(dev);
+ struct file *filp;
+
+ drm_gem_private_object_init(dev, obj, size);
+
+ filp = shmem_file_setup_with_mnt(i915->mm.gemfs, "i915", size,
+ VM_NORESERVE);
+ if (IS_ERR(filp))
+ return PTR_ERR(filp);
+
+ obj->filp = filp;
+
+ return 0;
+}
+
struct drm_i915_gem_object *
i915_gem_object_create(struct drm_i915_private *dev_priv, u64 size)
{
@@ -4303,7 +4323,7 @@ i915_gem_object_create(struct drm_i915_private *dev_priv, u64 size)
if (obj == NULL)
return ERR_PTR(-ENOMEM);

- ret = drm_gem_object_init(&dev_priv->drm, &obj->base, size);
+ ret = i915_gem_object_create_shmem(&dev_priv->drm, &obj->base, size);
if (ret)
goto fail;

@@ -4878,7 +4898,13 @@ i915_gem_load_init_fences(struct drm_i915_private *dev_priv)
int
i915_gem_load_init(struct drm_i915_private *dev_priv)
{
- int err = -ENOMEM;
+ int err;
+
+ err = i915_gemfs_init(dev_priv);
+ if (err)
+ return err;
+
+ err = -ENOMEM;

dev_priv->objects = KMEM_CACHE(drm_i915_gem_object, SLAB_HWCACHE_ALIGN);
if (!dev_priv->objects)
@@ -4942,6 +4968,8 @@ i915_gem_load_init(struct drm_i915_private *dev_priv)
err_objects:
kmem_cache_destroy(dev_priv->objects);
err_out:
+ i915_gemfs_fini(dev_priv);
+
return err;
}

@@ -4964,6 +4992,8 @@ void i915_gem_load_cleanup(struct drm_i915_private *dev_priv)

/* And ensure that our DESTROY_BY_RCU slabs are truly destroyed */
rcu_barrier();
+
+ i915_gemfs_fini(dev_priv);
}

int i915_gem_freeze(struct drm_i915_private *dev_priv)
diff --git a/drivers/gpu/drm/i915/i915_gemfs.c b/drivers/gpu/drm/i915/i915_gemfs.c
new file mode 100644
index 000000000000..168d0bd98f60
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gemfs.c
@@ -0,0 +1,52 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+
+#include "i915_drv.h"
+#include "i915_gemfs.h"
+
+int i915_gemfs_init(struct drm_i915_private *i915)
+{
+ struct file_system_type *type;
+ struct vfsmount *gemfs;
+
+ type = get_fs_type("tmpfs");
+ if (!type)
+ return -ENODEV;
+
+ gemfs = kern_mount(type);
+ if (IS_ERR(gemfs))
+ return PTR_ERR(gemfs);
+
+ i915->mm.gemfs = gemfs;
+
+ return 0;
+}
+
+void i915_gemfs_fini(struct drm_i915_private *i915)
+{
+ kern_unmount(i915->mm.gemfs);
+}
diff --git a/drivers/gpu/drm/i915/i915_gemfs.h b/drivers/gpu/drm/i915/i915_gemfs.h
new file mode 100644
index 000000000000..cca8bdc5b93e
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_gemfs.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright © 2017 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#ifndef __I915_GEMFS_H__
+#define __I915_GEMFS_H__
+
+struct drm_i915_private;
+
+int i915_gemfs_init(struct drm_i915_private *i915);
+
+void i915_gemfs_fini(struct drm_i915_private *i915);
+
+#endif
diff --git a/drivers/gpu/drm/i915/selftests/mock_gem_device.c b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
index 678723430d78..4d82c978a769 100644
--- a/drivers/gpu/drm/i915/selftests/mock_gem_device.c
+++ b/drivers/gpu/drm/i915/selftests/mock_gem_device.c
@@ -83,6 +83,8 @@ static void mock_device_release(struct drm_device *dev)
kmem_cache_destroy(i915->vmas);
kmem_cache_destroy(i915->objects);

+ i915_gemfs_fini(i915);
+
drm_dev_fini(&i915->drm);
put_device(&i915->drm.pdev->dev);
}
@@ -189,9 +191,13 @@ struct drm_i915_private *mock_gem_device(void)

i915->gt.awake = true;

+ err = i915_gemfs_init(i915);
+ if (err)
+ goto err_wq;
+
i915->objects = KMEM_CACHE(mock_object, SLAB_HWCACHE_ALIGN);
if (!i915->objects)
- goto err_wq;
+ goto err_gemfs;

i915->vmas = KMEM_CACHE(i915_vma, SLAB_HWCACHE_ALIGN);
if (!i915->vmas)
@@ -249,6 +255,8 @@ struct drm_i915_private *mock_gem_device(void)
kmem_cache_destroy(i915->vmas);
err_objects:
kmem_cache_destroy(i915->objects);
+err_gemfs:
+ i915_gemfs_fini(i915);
err_wq:
destroy_workqueue(i915->wq);
put_device:
--
2.13.4

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