From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 62E99CFD376 for ; Tue, 2 Dec 2025 10:17:35 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4A50710E5F5; Tue, 2 Dec 2025 10:17:30 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=collabora.com header.i=@collabora.com header.b="hzLTIZO4"; dkim-atps=neutral Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) by gabe.freedesktop.org (Postfix) with ESMTPS id 5ABD110E5F5; Tue, 2 Dec 2025 10:17:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1764670648; bh=9th0tLAngJVGd6qH652rQnjACAMqlVf6KbfxdfP115A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hzLTIZO4FKybVytLPB8Q+wJpU5gvTnj6tCpOXfRP0sStlfSW6Qiyz9bqu5Dtm105w t3RbjK7qOT7oqij4vDG1DT67koICrUXrGdim26gz/c+v8zMMioqe+1sSvO5MhNFxY+ iwJZ+opUrw9DpGNJdGg7nmWZi/noPh/rL3GKidVw5xc9nBtX5R1KVbdnFc0NXvgAtV srexQGdbfrhhSQmbGx/gAjdwfYwYgm5aQG7s0/8DFuJhL1sDOvKA+2qAEasF/Vvz1g +PSc2NsvfgY/zQi0YyP7hoMRhU4bRsBMAttp76kE0Rqy12yAb8baiZMsiFiHzrlMA2 23xevis+eKEDA== Received: from debian-rockchip-rock5b-rk3588.. (unknown [IPv6:2a01:e0a:5e3:6100:826d:bc07:e98c:84a]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: loicmolinari) by bali.collaboradmins.com (Postfix) with ESMTPSA id 2176017E13F1; Tue, 2 Dec 2025 11:17:27 +0100 (CET) From: =?UTF-8?q?Lo=C3=AFc=20Molinari?= To: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , Boris Brezillon , Rob Herring , Steven Price , Liviu Dudau , Melissa Wen , =?UTF-8?q?Ma=C3=ADra=20Canal?= , Hugh Dickins , Baolin Wang , Andrew Morton , =?UTF-8?q?Lo=C3=AFc=20Molinari?= , Al Viro , =?UTF-8?q?Miko=C5=82aj=20Wasiak?= , Christian Brauner , Nitin Gote , Andi Shyti , Jonathan Corbet , Christopher Healy , Matthew Wilcox , Bagas Sanjaya Cc: linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, linux-doc@vger.kernel.org, kernel@collabora.com Subject: [PATCH v11 04/10] drm/gem: Add huge tmpfs mountpoint helpers Date: Tue, 2 Dec 2025 11:17:14 +0100 Message-ID: <20251202101720.3129-5-loic.molinari@collabora.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251202101720.3129-1-loic.molinari@collabora.com> References: <20251202101720.3129-1-loic.molinari@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" Add the drm_gem_huge_mnt_create() and drm_gem_get_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 retrieves the dedicated huge tmpfs mountpoint used by a DRM device. The next commits will port drivers to these helpers. 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: - remove 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 v6: - move huge_mnt doc into ifdef'd section - either inline or export drm_gem_huge_mnt_create() v7: - include in drm_gem.h v9: - replace drm_gem_has_huge_mnt() by drm_gem_get_huge_mnt() v11: - doc fixes - add Boris and Maíra R-bs Signed-off-by: Loïc Molinari Reviewed-by: Boris Brezillon Reviewed-by: Maíra Canal --- drivers/gpu/drm/drm_gem.c | 57 +++++++++++++++++++++++++++++++++++++++ include/drm/drm_device.h | 15 +++++++++++ include/drm/drm_gem.h | 33 +++++++++++++++++++++++ 3 files changed, 105 insertions(+) diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c index 933fc89dd648..32dddb23e211 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 +85,60 @@ * 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); +} + +/** + * drm_gem_huge_mnt_create - Create, mount and use a huge tmpfs mountpoint + * @dev: DRM device that will use the huge tmpfs mountpoint + * @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 for @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. + */ +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_get_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 5af49c5c3778..bc78fb77cc27 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; +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + /** + * @huge_mnt: + * + * Huge tmpfs mountpoint used at GEM object initialization + * drm_gem_object_init(). Drivers can call drm_gem_huge_mnt_create() to + * create, mount and use it. The default tmpfs mountpoint (`shm_mnt`) is + * used if NULL. + */ + 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..97b5fca8966d 100644 --- a/include/drm/drm_gem.h +++ b/include/drm/drm_gem.h @@ -40,6 +40,9 @@ #include #include +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#include +#endif #include struct iosys_map; @@ -492,6 +495,36 @@ struct drm_gem_object { DRM_GEM_FOPS,\ } +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +int drm_gem_huge_mnt_create(struct drm_device *dev, const char *value); +#else +static inline int drm_gem_huge_mnt_create(struct drm_device *dev, + const char *value) +{ + return 0; +} +#endif + +/** + * drm_gem_get_huge_mnt - Get the huge tmpfs mountpoint used by a DRM device + * @dev: DRM device + + * This function gets the huge tmpfs mountpoint used by DRM device @dev. A huge + * tmpfs mountpoint is used instead of `shm_mnt` after a successful call to + * drm_gem_huge_mnt_create() when CONFIG_TRANSPARENT_HUGEPAGE is enabled. + + * Returns: + * The huge tmpfs mountpoint in use, NULL otherwise. + */ +static inline struct vfsmount *drm_gem_get_huge_mnt(struct drm_device *dev) +{ +#ifdef CONFIG_TRANSPARENT_HUGEPAGE + return dev->huge_mnt; +#else + return NULL; +#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