/* * SPDX-License-Identifier: MIT * * Copyright © 2017 Intel Corporation */ #include #include #include "i915_drv.h" #include "i915_gemfs.h" #include "i915_utils.h" void i915_gemfs_init(struct drm_i915_private *i915) { #ifdef __linux__ char huge_opt[] = "huge=within_size"; /* r/w */ struct file_system_type *type; struct vfsmount *gemfs; /* * 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; gemfs = vfs_kern_mount(type, SB_KERNMOUNT, type->name, huge_opt); if (IS_ERR(gemfs)) 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!"); #endif } void i915_gemfs_fini(struct drm_i915_private *i915) { #ifdef __linux__ kern_unmount(i915->mm.gemfs); #endif }