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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6BFFDCCA483 for ; Wed, 6 Jul 2022 15:32:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233885AbiGFPcj (ORCPT ); Wed, 6 Jul 2022 11:32:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44380 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233974AbiGFPcS (ORCPT ); Wed, 6 Jul 2022 11:32:18 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D5CEF27B1C; Wed, 6 Jul 2022 08:31:40 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 90B2AB81D93; Wed, 6 Jul 2022 15:31:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 57252C3411C; Wed, 6 Jul 2022 15:31:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657121498; bh=SuF4v3Uz5uTNz8Vjlm3/PnuewX3rlJ5M1kikWnOZ87c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kap7Dbsl3MImUUIbDe1lCtBNYHHFd5b7xtKE2uIXQAPy3ESeTbE4qdIyV45IBslLy 48ViL1ffYzMf4OUcfPj3OlS6q7zj6dmCvLTrtnxPaxiaOoNfHrXE5ITCCfwboJOCrw W0dTDrJgUsRuZYREmVcxwvNhWnDdof0hLt5OIqXYhOEbMBJjM3+qDZqka71fbawSys Yg8MKrGDo75c9OLXnogHJrA4ZrVk4Ku9l6XbDs4/i2LosQeAKl9DSVLCCuPh3RQqZU ++oyXirPeWxDyteKR1smzCUulXOU0PvtjiEUMlO6jU2dgnQRmred6Um2e3U55R6ZoH ysWOxEWZSvR6w== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Javier Martinez Canillas , Daniel Vetter , Sasha Levin , corbet@lwn.net, tzimmermann@suse.de, bp@suse.de, gregkh@linuxfoundation.org, linux-doc@vger.kernel.org Subject: [PATCH AUTOSEL 5.18 16/22] firmware: sysfb: Add sysfb_disable() helper function Date: Wed, 6 Jul 2022 11:30:34 -0400 Message-Id: <20220706153041.1597639-16-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220706153041.1597639-1-sashal@kernel.org> References: <20220706153041.1597639-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org From: Javier Martinez Canillas [ Upstream commit bde376e9de3c0bc55eedc8956b0f114c05531595 ] This can be used by subsystems to unregister a platform device registered by sysfb and also to disable future platform device registration in sysfb. Suggested-by: Daniel Vetter Signed-off-by: Javier Martinez Canillas Reviewed-by: Daniel Vetter Link: https://patchwork.freedesktop.org/patch/msgid/20220607182338.344270-3-javierm@redhat.com Signed-off-by: Sasha Levin --- .../driver-api/firmware/other_interfaces.rst | 6 +++ drivers/firmware/sysfb.c | 54 ++++++++++++++++--- include/linux/sysfb.h | 12 +++++ 3 files changed, 66 insertions(+), 6 deletions(-) diff --git a/Documentation/driver-api/firmware/other_interfaces.rst b/Documentation/driver-api/firmware/other_interfaces.rst index b81794e0cfbb..06ac89adaafb 100644 --- a/Documentation/driver-api/firmware/other_interfaces.rst +++ b/Documentation/driver-api/firmware/other_interfaces.rst @@ -13,6 +13,12 @@ EDD Interfaces .. kernel-doc:: drivers/firmware/edd.c :internal: +Generic System Framebuffers Interface +------------------------------------- + +.. kernel-doc:: drivers/firmware/sysfb.c + :export: + Intel Stratix10 SoC Service Layer --------------------------------- Some features of the Intel Stratix10 SoC require a level of privilege diff --git a/drivers/firmware/sysfb.c b/drivers/firmware/sysfb.c index b032f40a92de..1f276f108cc9 100644 --- a/drivers/firmware/sysfb.c +++ b/drivers/firmware/sysfb.c @@ -34,21 +34,59 @@ #include #include +static struct platform_device *pd; +static DEFINE_MUTEX(disable_lock); +static bool disabled; + +static bool sysfb_unregister(void) +{ + if (IS_ERR_OR_NULL(pd)) + return false; + + platform_device_unregister(pd); + pd = NULL; + + return true; +} + +/** + * sysfb_disable() - disable the Generic System Framebuffers support + * + * This disables the registration of system framebuffer devices that match the + * generic drivers that make use of the system framebuffer set up by firmware. + * + * It also unregisters a device if this was already registered by sysfb_init(). + * + * Context: The function can sleep. A @disable_lock mutex is acquired to serialize + * against sysfb_init(), that registers a system framebuffer device. + */ +void sysfb_disable(void) +{ + mutex_lock(&disable_lock); + sysfb_unregister(); + disabled = true; + mutex_unlock(&disable_lock); +} +EXPORT_SYMBOL_GPL(sysfb_disable); + static __init int sysfb_init(void) { struct screen_info *si = &screen_info; struct simplefb_platform_data mode; - struct platform_device *pd; const char *name; bool compatible; - int ret; + int ret = 0; + + mutex_lock(&disable_lock); + if (disabled) + goto unlock_mutex; /* try to create a simple-framebuffer device */ compatible = sysfb_parse_mode(si, &mode); if (compatible) { pd = sysfb_create_simplefb(si, &mode); if (!IS_ERR(pd)) - return 0; + goto unlock_mutex; } /* if the FB is incompatible, create a legacy framebuffer device */ @@ -60,8 +98,10 @@ static __init int sysfb_init(void) name = "platform-framebuffer"; pd = platform_device_alloc(name, 0); - if (!pd) - return -ENOMEM; + if (!pd) { + ret = -ENOMEM; + goto unlock_mutex; + } sysfb_apply_efi_quirks(pd); @@ -73,9 +113,11 @@ static __init int sysfb_init(void) if (ret) goto err; - return 0; + goto unlock_mutex; err: platform_device_put(pd); +unlock_mutex: + mutex_unlock(&disable_lock); return ret; } diff --git a/include/linux/sysfb.h b/include/linux/sysfb.h index 708152e9037b..8ba8b5be5567 100644 --- a/include/linux/sysfb.h +++ b/include/linux/sysfb.h @@ -55,6 +55,18 @@ struct efifb_dmi_info { int flags; }; +#ifdef CONFIG_SYSFB + +void sysfb_disable(void); + +#else /* CONFIG_SYSFB */ + +static inline void sysfb_disable(void) +{ +} + +#endif /* CONFIG_SYSFB */ + #ifdef CONFIG_EFI extern struct efifb_dmi_info efifb_dmi_list[]; -- 2.35.1