From patchwork Tue Apr 19 14:18:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Zyngier X-Patchwork-Id: 565097 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 09AEFC35295 for ; Tue, 19 Apr 2022 14:19:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1353160AbiDSOV5 (ORCPT ); Tue, 19 Apr 2022 10:21:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36132 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1353076AbiDSOVt (ORCPT ); Tue, 19 Apr 2022 10:21:49 -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 AF3821900C; Tue, 19 Apr 2022 07:19:05 -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 69AB7B819EB; Tue, 19 Apr 2022 14:19:04 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1ACF6C385AD; Tue, 19 Apr 2022 14:19:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1650377943; bh=tJvSyYshW26j5siNkBNgQg3cRVt6d+7DxHaeBiQOvXo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FfY5L0VOuX+LVyyGtaVjdNIa515Lqxx3f69/HqI0Fdt5M6zqySwTGRYePfyqFJe2O 26H5WPR6j9j8CJ+GK+eeVkd8ecMci/yalwvtp1hd+W7299YJNuzTX3AxOq4wV7VU29 cV0gRRMGfrTvqkh31KZF339f2xGKzUA1sp9a9k/eVe+XUN0S0qcxNWQnJoth57U67V y6wAFoVOGobG7tr0StxiuB8fgmGs9z46ZE3vPo7YMxZFxswGzORIW6hX5d7Z1eCv/i M6Q1emDXjN21j4VVrHLvsnnZT01cguWqMowtD9/M/eVEn4GFjKtXlPYnqGTz5PUqbf LfU3oNhc8HOSg== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.lan) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1ngoh3-005MFS-4m; Tue, 19 Apr 2022 15:19:01 +0100 From: Marc Zyngier To: linux-kernel@vger.kernel.org Cc: Linus Walleij , Bartosz Golaszewski , Thierry Reding , Joey Gouly , Jonathan Hunter , Hector Martin , Sven Peter , Alyssa Rosenzweig , Bjorn Andersson , Andy Gross , Jeffrey Hugo , Thomas Gleixner , Basavaraj Natikar , Shyam Sundar S K , Andy Shevchenko , linux-gpio@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, kernel-team@android.com Subject: [PATCH v3 09/10] gpio: Update TODO to mention immutable irq_chip structures Date: Tue, 19 Apr 2022 15:18:45 +0100 Message-Id: <20220419141846.598305-10-maz@kernel.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20220419141846.598305-1-maz@kernel.org> References: <20220419141846.598305-1-maz@kernel.org> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: linux-kernel@vger.kernel.org, linus.walleij@linaro.org, brgl@bgdev.pl, thierry.reding@gmail.com, joey.gouly@arm.com, jonathanh@nvidia.com, marcan@marcan.st, sven@svenpeter.dev, alyssa@rosenzweig.io, bjorn.andersson@linaro.org, agross@kernel.org, jeffrey.l.hugo@gmail.com, tglx@linutronix.de, Basavaraj.Natikar@amd.com, Shyam-sundar.S-k@amd.com, andy.shevchenko@gmail.com, linux-gpio@vger.kernel.org, linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-arm-msm@vger.kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org 5 drivers are converted, a few hundred to go. Definitely worth of a TODO entry, in the hope that someone will notice it and do a bulk update. Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier --- drivers/gpio/TODO | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index b8b1473a5b1e..f87ff3fa8a53 100644 --- a/drivers/gpio/TODO +++ b/drivers/gpio/TODO @@ -178,3 +178,22 @@ discussed but the idea is to provide a low-level access point for debugging and hacking and to expose all lines without the need of any exporting. Also provide ample ammunition to shoot oneself in the foot, because this is debugfs after all. + + +Moving over to immutable irq_chip structures + +Most of the gpio chips implementing interrupt support rely on gpiolib +intercepting some of the irq_chip callbacks, preventing the structures +from being made read-only and forcing duplication of structures that +should otherwise be unique. + +The solution is to call into the gpiolib code when needed (resource +management, enable/disable or unmask/mask callbacks), and to let the +core code know about that by exposing a flag (IRQCHIP_IMMUTABLE) in +the irq_chip structure. The irq_chip structure can then be made unique +and const. + +A small number of drivers have been converted (pl061, tegra186, msm, +amd, apple), and can be used as examples of how to proceed with this +conversion. Note that drivers using the generic irqchip framework +cannot be converted yet, but watch this space!