1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/gem/i915_gemfs.c b/drivers/gpu/drm/i915/gem/i915_gemfs.c
new file mode 100644
index 000000000000..1f1290214031
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gemfs.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2017 Intel Corporation
+ */
+
+#include <linux/fs.h>
+#include <linux/mount.h>
+#include <linux/fs_context.h>
+
+#include <drm/drm_print.h>
+
+#include "i915_drv.h"
+#include "i915_gemfs.h"
+#include "i915_utils.h"
+
+void i915_gemfs_init(struct drm_i915_private *i915)
+{
+	struct file_system_type *type;
+	struct fs_context *fc;
+	struct vfsmount *gemfs;
+	int ret;
+
+	/*
+	 * By creating our own shmemfs mountpoint, we can pass in
+	 * mount flags that better match our usecase.
+	 *
+	 * One example, although it is probably better with a per-file
+	 * control, is selecting huge page allocations ("huge=within_size").
+	 * However, we only do so on platforms which benefit from it, or to
+	 * offset the overhead of iommu lookups, where with latter it is a net
+	 * win even on platforms which would otherwise see some performance
+	 * regressions such a slow reads issue on Broadwell and Skylake.
+	 */
+
+	if (GRAPHICS_VER(i915) < 11 && !i915_vtd_active(i915))
+		return;
+
+	if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
+		goto err;
+
+	type = get_fs_type("tmpfs");
+	if (!type)
+		goto err;
+
+	fc = fs_context_for_mount(type, SB_KERNMOUNT);
+	if (IS_ERR(fc))
+		goto err;
+	ret = vfs_parse_fs_string(fc, "source", "tmpfs");
+	if (!ret)
+		ret = vfs_parse_fs_string(fc, "huge", "within_size");
+	if (!ret)
+		gemfs = fc_mount_longterm(fc);
+	put_fs_context(fc);
+	if (ret)
+		goto err;
+
+	i915->mm.gemfs = gemfs;
+	drm_info(&i915->drm, "Using Transparent Hugepages\n");
+	return;
+
+err:
+	drm_notice(&i915->drm,
+		   "Transparent Hugepage support is recommended for optimal performance%s\n",
+		   GRAPHICS_VER(i915) >= 11 ? " on this platform!" :
+					      " when IOMMU is enabled!");
+}
+
+void i915_gemfs_fini(struct drm_i915_private *i915)
+{
+	kern_unmount(i915->mm.gemfs);
+}