drivers/gpu/drm/v3d/v3d_gemfs.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /* Copyright (C) 2024 Raspberry Pi */
   3
   4 #include <linux/fs.h>
   5 #include <linux/mount.h>
   6
   7 #include "v3d_drv.h"
   8
   9 void v3d_gemfs_init(struct v3d_dev *v3d)
  10 {
  11         char huge_opt[] = "huge=within_size";
  12         struct file_system_type *type;
  13         struct vfsmount *gemfs;
  14
  15         /*
  16          * By creating our own shmemfs mountpoint, we can pass in
  17          * mount flags that better match our usecase. However, we
  18          * only do so on platforms which benefit from it.
  19          */
  20         if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE))
  21                 goto err;
  22
  23         /* The user doesn't want to enable Super Pages */
  24         if (!super_pages)
  25                 goto err;
  26
  27         type = get_fs_type("tmpfs");
  28         if (!type)
  29                 goto err;
  30
  31         gemfs = vfs_kern_mount(type, SB_KERNMOUNT, type->name, huge_opt);
  32         if (IS_ERR(gemfs))
  33                 goto err;
  34
  35         v3d->gemfs = gemfs;
  36         drm_info(&v3d->drm, "Using Transparent Hugepages\n");
  37
  38         return;
  39
  40 err:
  41         v3d->gemfs = NULL;
  42         drm_notice(&v3d->drm,
  43                    "Transparent Hugepage support is recommended for optimal performance on this platform!\n");
  44 }
  45
  46 void v3d_gemfs_fini(struct v3d_dev *v3d)
  47 {
  48         if (v3d->gemfs)
  49                 kern_unmount(v3d->gemfs);
  50 }