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 #include <linux/fs_context.h> 7 8 #include <drm/drm_print.h> 9 10 #include "v3d_drv.h" 11 12 void v3d_gemfs_init(struct v3d_dev *v3d) 13 { 14 struct file_system_type *type; 15 struct fs_context *fc; 16 struct vfsmount *gemfs; 17 int ret; 18 19 /* 20 * By creating our own shmemfs mountpoint, we can pass in 21 * mount flags that better match our usecase. However, we 22 * only do so on platforms which benefit from it. 23 */ 24 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) 25 goto err; 26 27 /* The user doesn't want to enable Super Pages */ 28 if (!super_pages) 29 goto err; 30 31 type = get_fs_type("tmpfs"); 32 if (!type) 33 goto err; 34 35 fc = fs_context_for_mount(type, SB_KERNMOUNT); 36 if (IS_ERR(fc)) 37 goto err; 38 ret = vfs_parse_fs_string(fc, "source", "tmpfs"); 39 if (!ret) 40 ret = vfs_parse_fs_string(fc, "huge", "within_size"); 41 if (!ret) 42 gemfs = fc_mount_longterm(fc); 43 put_fs_context(fc); 44 if (ret) 45 goto err; 46 47 v3d->gemfs = gemfs; 48 drm_info(&v3d->drm, "Using Transparent Hugepages\n"); 49 50 return; 51 52 err: 53 v3d->gemfs = NULL; 54 drm_notice(&v3d->drm, 55 "Transparent Hugepage support is recommended for optimal performance on this platform!\n"); 56 } 57 58 void v3d_gemfs_fini(struct v3d_dev *v3d) 59 { 60 if (v3d->gemfs) 61 kern_unmount(v3d->gemfs); 62 } 63