Add the drm_gem_huge_mnt_create() and drm_gem_has_huge_mnt() helpers to avoid code duplication in the i915, V3D, Panfrost and Panthor drivers. The former creates and mounts a dedicated huge tmpfs mountpoint, for the lifetime of a DRM device, used at GEM object initialization. The latter checks whether a dedicated huge tmpfs mountpoint is in use by a DRM device. The next commits will port drivers to this helper. v3: - store huge tmpfs mountpoint in drm_device v4: - return 0 in builds with CONFIG_TRANSPARENT_HUGEPAGE=n - return 0 when huge_mnt already exists - use new vfs_parse_fs_string() helper v5: - removed warning on !dev->huge_mnt and reset to NULL on free - inline drm_gem_huge_mnt_create() to remove func from text and avoid calls in builds with CONFIG_TRANSPARENT_HUGEPAGE=n - compile out drm_device's huge_mnt field in builds with CONFIG_TRANSPARENT_HUGEPAGE=n - add drm_gem_has_huge_mnt() helper Signed-off-by: Loïc Molinari --- drivers/gpu/drm/drm_gem.c | 39 +++++++++++++++++++++++++++++ include/drm/drm_device.h | 15 +++++++++++ include/drm/drm_gem.h | 52 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 106 insertions(+) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index a98d5744cc6c..161da048330e 100644 --- a/drivers/gpu/drm/drm_gem.c +++ b/drivers/gpu/drm/drm_gem.c @@ -29,6 +29,9 @@ #include #include #include +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#include +#endif #include #include #include @@ -82,6 +85,42 @@ * up at a later date, and as our interface with shmfs for memory allocation. */ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void drm_gem_huge_mnt_free(struct drm_device *dev, void *data) +{ + kern_unmount(dev->huge_mnt); +} + +int __drm_gem_huge_mnt_create(struct drm_device *dev, const char *value) +{ + struct file_system_type *type; + struct fs_context *fc; + int ret; + + if (unlikely(drm_gem_has_huge_mnt(dev))) + return 0; + + type = get_fs_type("tmpfs"); + if (unlikely(!type)) + return -EOPNOTSUPP; + fc = fs_context_for_mount(type, SB_KERNMOUNT); + if (IS_ERR(fc)) + return PTR_ERR(fc); + ret = vfs_parse_fs_string(fc, "source", "tmpfs"); + if (unlikely(ret)) + return -ENOPARAM; + ret = vfs_parse_fs_string(fc, "huge", value); + if (unlikely(ret)) + return -ENOPARAM; + + dev->huge_mnt = fc_mount_longterm(fc); + put_fs_context(fc); + + return drmm_add_action_or_reset(dev, drm_gem_huge_mnt_free, NULL); +} +EXPORT_SYMBOL_GPL(__drm_gem_huge_mnt_create); +#endif + static void drm_gem_init_release(struct drm_device *dev, void *ptr) { diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h index 778b2cca6c49..684939987d83 100644 --- a/include/drm/drm_device.h +++ b/include/drm/drm_device.h @@ -3,6 +3,9 @@ #include #include +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#include +#endif #include #include #include @@ -168,6 +171,18 @@ struct drm_device { */ struct drm_master *master; + /** + * @huge_mnt: + * + * Huge tmpfs mountpoint used at GEM object initialization + * drm_gem_object_init(). Drivers can call drm_gem_huge_mnt_create() to + * create a huge tmfps mountpoint. The default tmpfs mountpoint + * (`shm_mnt`) is used if NULL. + */ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + struct vfsmount *huge_mnt; +#endif + /** * @driver_features: per-device driver features * diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h index 7c8bd67d087c..9845854850fb 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -492,6 +492,58 @@ struct drm_gem_object { DRM_GEM_FOPS,\ } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +int __drm_gem_huge_mnt_create(struct drm_device *dev, const char *value); +#endif + +/** + * drm_gem_huge_mnt_create - Create, mount and use a huge tmpfs mountpoint + * @dev: DRM device a huge tmpfs mountpoint should be used with + * @value: huge tmpfs mount option value + * + * This function creates and mounts a dedicated huge tmpfs mountpoint for the + * lifetime of the DRM device @dev which is used at GEM object initialization + * with drm_gem_object_init(). + * + * The most common option value @value is "within_size" which only allocates + * huge pages if the page will be fully within the GEM object size. "always", + * "advise" and "never" are supported too but the latter would just create a + * mountpoint similar to the default one (`shm_mnt`). See shmemfs and + * Transparent Hugepage for more information. + * + * Returns: + * 0 on success or a negative error code on failure. + */ +static inline int drm_gem_huge_mnt_create(struct drm_device *dev, + const char *value) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + return __drm_gem_huge_mnt_create(dev, value); +#else + return 0; +#endif +} + +/** + * drm_gem_has_huge_mnt - Check if a huge tmpfs mountpoint is in use + * @dev: DRM device + * + * This function checks whether a huge tmpfs mountpoint is in use after by DRM + * device @dev. A huge tmpfs mountpoint is used after a successful call to + * drm_gem_huge_mnt_create() on builds with Transparent Hugepage enabled. + * + * Returns: + * true on success, false otherwise. + */ +static inline bool drm_gem_has_huge_mnt(struct drm_device *dev) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + return !!dev->huge_mnt; +#else + return false; +#endif +} + void drm_gem_object_release(struct drm_gem_object *obj); void drm_gem_object_free(struct kref *kref); int drm_gem_object_init(struct drm_device *dev, -- 2.47.3