From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bali.collaboradmins.com (bali.collaboradmins.com [148.251.105.195]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1C3CE1AAE13 for ; Tue, 30 Sep 2025 10:57:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.251.105.195 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759229853; cv=none; b=WzWblzWrm/T1RgEYkuLn4DjAYBq7jET7ZZUGZuyvUE+HyMPkwDjScKctZD78D05KfZ2BJ1Cdk6LClEIJWhqlaqQlJJnGen79kWBEkfFSorXuOBT6iaMoArFZrowg3iJauwJLEtJenso50VG63F2jN7njttBIf0VIY5TE1w/TiMg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759229853; c=relaxed/simple; bh=6bPRcsgjW5miijm89Vj9ztPqCVHtA9OfZProSwKLM+E=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FbF4lS3bDlojcPEVD2izDjnR2BVS6qt0XiM2uGxgTKliEKL/dvFsHwjEaJsKxrirosZ/rP0vHZIUV3sN6kSWaEg0UEJJxkkJ67esR3Bn3TszCh+zisoZ0XCtcFZe9pW8qongJDatbkSmkwginUB6dPGB0qm/urQc4NxaUalgLc4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b=lcUUCjon; arc=none smtp.client-ip=148.251.105.195 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=collabora.com header.i=@collabora.com header.b="lcUUCjon" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1759229849; bh=6bPRcsgjW5miijm89Vj9ztPqCVHtA9OfZProSwKLM+E=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=lcUUCjonC+V4D2GtM4PuXn8rRIxReNC+RXOaJZ7hhwdzpU5mJal943IHtXfksU6wu 1D4iYmyYsIQxCHCBDNgn2L/cw/FXXWt6qkiOP9BOrFZOE5VtEVtOs3UMLbTPqlRi7m sKXNlWf3l89UmYA7IFySASPm0/qugfjqrl/9Fy28nPJgbr6M6qH4YrQBz4x7zBUoER 1Im9nrbMPTENN7AdmsIDsaHOzwTV3uVEXlQrAUK8WQc5UWwjVWbhHlBwe+whDMd3ua rnCpyrhWzx7KD6aATwtJa8IFUPOVSk/k5fYDLMd24rXPk8ymgdwszEHPAfqdwn10ho td+aeBNfzDZRQ== Received: from fedora (unknown [IPv6:2a01:e0a:2c:6930:d919:a6e:5ea1:8a9f]) (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: bbrezillon) by bali.collaboradmins.com (Postfix) with ESMTPSA id 48A0917E0097; Tue, 30 Sep 2025 12:57:28 +0200 (CEST) Date: Tue, 30 Sep 2025 12:57:25 +0200 From: Boris Brezillon To: =?UTF-8?B?TG/Dr2M=?= Molinari Cc: Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter , Jani Nikula , Joonas Lahtinen , Rodrigo Vivi , Tvrtko Ursulin , Rob Herring , Steven Price , Liviu Dudau , Melissa Wen , =?UTF-8?B?TWHDrXJh?= Canal , Hugh Dickins , Baolin Wang , Andrew Morton , Al Viro , =?UTF-8?B?TWlrb8WCYWo=?= Wasiak , Christian Brauner , Nitin Gote , Andi Shyti , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, linux-mm@kvack.org, kernel@collabora.com Subject: Re: [PATCH 3/8] drm/shmem-helper: Add huge tmpfs mount point helpers Message-ID: <20250930125725.258e74a5@fedora> In-Reply-To: <20250929200316.18417-4-loic.molinari@collabora.com> References: <20250929200316.18417-1-loic.molinari@collabora.com> <20250929200316.18417-4-loic.molinari@collabora.com> Organization: Collabora X-Mailer: Claws Mail 4.3.1 (GTK 3.24.49; x86_64-redhat-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On Mon, 29 Sep 2025 22:03:11 +0200 Lo=C3=AFc Molinari wrote: > Add the drm_gem_shmem_helper_huge_mnt_create() and > drm_gem_shmem_helper_huge_mnt_free() helpers to avoid code duplication > in the i915 and v3d drivers (and soon panfrost/panthor). >=20 > Signed-off-by: Lo=C3=AFc Molinari > --- > drivers/gpu/drm/drm_gem_shmem_helper.c | 56 ++++++++++++++++++++++++++ > include/drm/drm_gem_shmem_helper.h | 14 +++++++ > 2 files changed, 70 insertions(+) >=20 > diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm= _gem_shmem_helper.c > index 22c4b09e10a3..808721b8be3e 100644 > --- a/drivers/gpu/drm/drm_gem_shmem_helper.c > +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c > @@ -5,7 +5,9 @@ > =20 > #include > #include > +#include > #include > +#include > #include > #include > #include > @@ -36,6 +38,60 @@ MODULE_IMPORT_NS("DMA_BUF"); > * drm_gem_shmem_vmap()). These helpers perform the necessary type conve= rsion. > */ > =20 > +static int drm_gem_shmem_add_fc_param(struct fs_context *fc, const char = *key, > + const char *value) > +{ > + return vfs_parse_fs_string(fc, key, value, strlen(value)); > +} > + > +/** > + * drm_gem_shmem_huge_mnt_create - Create a huge tmpfs mountpoint > + * @value: huge tmpfs mount option value > + * > + * This function creates and mounts an internal huge tmpfs mountpoint fo= r use > + * with the drm_gem_shmem_create_with_mnt() function. > + * > + * The most common option value is "within_size" which only allocates hu= ge pages > + * if the page will be fully within the GEM object size. "always", "advi= se" and > + * "never" are supported too but the latter would just create a mountpoi= nt > + * similar to default "shm_mnt" one. See shmemfs and Transparent Hugepag= e for > + * more information. > + * > + * Returns: > + * A struct vfsmount * on success or an ERR_PTR()-encoded negative error= code on > + * failure. > + */ > +struct vfsmount *drm_gem_shmem_huge_mnt_create(const char *value) Given drm_gem_object_init_with_mnt() lives in drm_gem.c and doesn't have the _shmem_ prefix, I'd be tempted to move this helper to drm_gem.c and rename it drm_gem_huge_mnt_create(). Actually, as I said in the panthor patch, I believe this could also be passed a drm_device and have the resulting vfsmount stored in drm_device::huge_mnt. This way we could get rid of drm_gem_shmem_create_with_mnt() altogether. > +{ > + struct file_system_type *type; > + struct fs_context *fc; > + struct vfsmount *mnt; > + int ret; > + > + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) > + return ERR_PTR(-EOPNOTSUPP); > + > + type =3D get_fs_type("tmpfs"); > + if (!type) > + return ERR_PTR(-EOPNOTSUPP); > + > + fc =3D fs_context_for_mount(type, SB_KERNMOUNT); > + if (IS_ERR(fc)) > + return ERR_CAST(fc); > + ret =3D drm_gem_shmem_add_fc_param(fc, "source", "tmpfs"); > + if (ret) > + return ERR_PTR(-ENOPARAM); > + ret =3D drm_gem_shmem_add_fc_param(fc, "huge", value); > + if (ret) > + return ERR_PTR(-ENOPARAM); > + > + mnt =3D fc_mount_longterm(fc); > + put_fs_context(fc); > + > + return mnt; > +} > +EXPORT_SYMBOL_GPL(drm_gem_shmem_huge_mnt_create); > + > static const struct drm_gem_object_funcs drm_gem_shmem_funcs =3D { > .free =3D drm_gem_shmem_object_free, > .print_info =3D drm_gem_shmem_object_print_info, > diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shm= em_helper.h > index 589f7bfe7506..5e153fb63f38 100644 > --- a/include/drm/drm_gem_shmem_helper.h > +++ b/include/drm/drm_gem_shmem_helper.h > @@ -107,6 +107,20 @@ struct drm_gem_shmem_object { > #define to_drm_gem_shmem_obj(obj) \ > container_of(obj, struct drm_gem_shmem_object, base) > =20 > +struct vfsmount *drm_gem_shmem_huge_mnt_create(const char *value); > + > +/** > + * drm_gem_shmem_huge_mnt_free - Release a huge tmpfs mountpoint. > + * @mnt: struct vfsmount * to release > + * > + * This function unmounts and releases an internal huge tmpfs mountpoint= . If > + * @mnt is NULL, no operation is performed. > + */ > +static inline void drm_gem_shmem_huge_mnt_free(struct vfsmount *mnt) > +{ > + kern_unmount(mnt); > +} > + > int drm_gem_shmem_init(struct drm_device *dev, struct drm_gem_shmem_obje= ct *shmem, size_t size); > struct drm_gem_shmem_object *drm_gem_shmem_create(struct drm_device *dev= , size_t size); > struct drm_gem_shmem_object *drm_gem_shmem_create_with_mnt(struct drm_de= vice *dev,