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 882A0C433F5 for ; Fri, 8 Apr 2022 16:13:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230346AbiDHQPz (ORCPT ); Fri, 8 Apr 2022 12:15:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34876 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231309AbiDHQPv (ORCPT ); Fri, 8 Apr 2022 12:15:51 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 4DF1375C32 for ; Fri, 8 Apr 2022 09:13:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1649434424; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=TJpTIeTAW53bGCMvTatNT6vUmRrWyDElzFlDd/19otY=; b=Zg1CPQMsKNWCT04j4ak9hgIePvQYJJjd9SbygvvFHHjOkLCvhFitHbZ+TpV9QrdSqWTWtU 0GrkjEMDuBiviZgDmuy6+0zE2ncG/0N8VzdzyYK8BtfBG9LFc5ZO545PqXuQXC/oiNx7KG W9qnt9ox+hk+9y+QZAAxfBY/qwNDfd0= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-49-i3R_7AxjMQ2fge-leuRZng-1; Fri, 08 Apr 2022 12:13:43 -0400 X-MC-Unique: i3R_7AxjMQ2fge-leuRZng-1 Received: by mail-wr1-f70.google.com with SMTP id z16-20020adff1d0000000b001ef7dc78b23so2349698wro.12 for ; Fri, 08 Apr 2022 09:13:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=TJpTIeTAW53bGCMvTatNT6vUmRrWyDElzFlDd/19otY=; b=ZAlaOOYjO9JWoLDNHXGfpo08/XpEdLhHkItYz20FaRvzg0lRmTgkUVKU9wPiaBSnDd 1HhOooAhHIJJ+uz26d1o8zg3hMPDrjK5n7Qz7CgA3y7Q7w3BtuVfW/LaQDjP+XYTraUn 6EN7dBFKcU+9DQ14+2y4weG+9TaecDPh9K5Ope4EV9bIg2qqDMgyjjDO7eShEQnpvD6/ JorL6DQ5hSXQxHwQ1x/yTtx4dhn6UIDh9ACFm/BovEsgi3Oyj60d/FRgyphyFdU7BUVI LuiqR3SRiBsapskMdTIaGGAxG8jEYPOHSZOEnevliKoeMvxo/x9cBpk3GEUr5RTnfCx5 IG3Q== X-Gm-Message-State: AOAM532no6LHOXNhty+qw5nKSjyfxyxk4G4ueHi66JIXkKqwSEfd1W9K ncaskHHCzjuBRmjJuzfcn2kedCfAt8+M3YYZvJkiMDLRemGxiVQr7fh+mL23hvdeDoy131idML1 CIKFohjtqLOzOVFqGRvBd X-Received: by 2002:a05:600c:3ba5:b0:38c:b19e:253c with SMTP id n37-20020a05600c3ba500b0038cb19e253cmr17515130wms.35.1649434422188; Fri, 08 Apr 2022 09:13:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJyb1bR0lxJrypE9QzahDsl2bHOBw/ximpksO0RRlntgb9gNAXEXCpGe5WPVpBzMKq9R/nVknw== X-Received: by 2002:a05:600c:3ba5:b0:38c:b19e:253c with SMTP id n37-20020a05600c3ba500b0038cb19e253cmr17515110wms.35.1649434421957; Fri, 08 Apr 2022 09:13:41 -0700 (PDT) Received: from minerva.home ([92.176.231.205]) by smtp.gmail.com with ESMTPSA id t15-20020adfeb8f000000b002060d26c211sm14377455wrn.114.2022.04.08.09.13.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 08 Apr 2022 09:13:41 -0700 (PDT) From: Javier Martinez Canillas To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , Daniel Vetter , dri-devel@lists.freedesktop.org, Thomas Zimmermann , Javier Martinez Canillas , Borislav Petkov , Jonathan Corbet , linux-doc@vger.kernel.org Subject: [PATCH v2 2/5] firmware: sysfb: Add helpers to unregister a pdev and disable registration Date: Fri, 8 Apr 2022 18:13:19 +0200 Message-Id: <20220408161322.270176-3-javierm@redhat.com> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220408161322.270176-1-javierm@redhat.com> References: <20220408161322.270176-1-javierm@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org These 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 --- Changes in v2: - Add kernel-doc comments and include in other_interfaces.rst (Daniel Vetter). .../driver-api/firmware/other_interfaces.rst | 6 ++ drivers/firmware/sysfb.c | 73 +++++++++++++++++-- include/linux/sysfb.h | 19 +++++ 3 files changed, 92 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..a50d2858ce4d 100644 --- a/drivers/firmware/sysfb.c +++ b/drivers/firmware/sysfb.c @@ -34,21 +34,78 @@ #include #include +static struct platform_device *pd; +static DEFINE_MUTEX(load_lock); +static bool disabled; + +/** + * 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. + * + * Context: The function can sleep. A @load_lock mutex is acquired to serialize + * against sysfb_init(), that registers a system framebuffer device and + * sysfb_try_unregister(), that tries to unregister framebuffer devices. + */ +void sysfb_disable(void) +{ + mutex_lock(&load_lock); + disabled = true; + mutex_unlock(&load_lock); +} +EXPORT_SYMBOL_GPL(sysfb_disable); + +/** + * sysfb_try_unregister() - attempt to unregister a system framebuffer device + * @dev: device to unregister + * + * This tries to unregister a system framebuffer device if this was registered + * by the Generic System Framebuffers. The device will only be unregistered if + * it was registered by sysfb_init(), otherwise it will not be unregistered. + * + * Context: The function can sleep. a @load_lock mutex is acquired to serialize + * against sysfb_init(), that registers a simple framebuffer device and + * sysfb_disable(), that disables the Generic System Framebuffers support. + * + * Return: + * * true - the device was unregistered successfully + * * false - the device was not unregistered + */ +bool sysfb_try_unregister(struct device *dev) +{ + bool ret = true; + + mutex_lock(&load_lock); + if (!pd || pd != to_platform_device(dev)) + return false; + + platform_device_unregister(to_platform_device(dev)); + pd = NULL; + mutex_unlock(&load_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(sysfb_try_unregister); + 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(&load_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 +117,10 @@ 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 +132,11 @@ static __init int sysfb_init(void) if (ret) goto err; - return 0; + goto unlock_mutex; err: platform_device_put(pd); +unlock_mutex: + mutex_unlock(&load_lock); return ret; } diff --git a/include/linux/sysfb.h b/include/linux/sysfb.h index 708152e9037b..e8c0313fac8f 100644 --- a/include/linux/sysfb.h +++ b/include/linux/sysfb.h @@ -55,6 +55,25 @@ struct efifb_dmi_info { int flags; }; +#ifdef CONFIG_SYSFB + +void sysfb_disable(void); +bool sysfb_try_unregister(struct device *dev); + +#else /* CONFIG_SYSFB */ + +static inline void sysfb_disable(void) +{ + +} + +static inline bool sysfb_try_unregister(struct device *dev) +{ + return false; +} + +#endif /* CONFIG_SYSFB */ + #ifdef CONFIG_EFI extern struct efifb_dmi_info efifb_dmi_list[]; -- 2.35.1