From nobody Wed Dec 24 03:18:25 2025 Received: from mail-wm1-f53.google.com (mail-wm1-f53.google.com [209.85.128.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6E2EB6D1A9 for ; Tue, 30 Jan 2024 12:48:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.53 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706618928; cv=none; b=I4IWo9IbNig9uAOll/MJCfGBEVa5FwLY3TqRpKcmiUTth93zjPT8ekSkf1oq9y99Cs65ZiDzWtXNJt5m0bzsv+WDApfo+rIXtwFp0klGVcbZhShSvJRko3FDgkl2EZFkPc82uC4wI6kdKmFUv1IrJgwzHhJe0tP+zGouM07Rh8E= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706618928; c=relaxed/simple; bh=w/6C0LXYSVlAEDD4c7gnkwzsfsPQEwhfaMmHG5iDNI0=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=H1//Q1+1UHA6aPwAPKaNOSTL8+N9XBxKSb9ePArg77KKeR/Bmyz+cSUh93TI86Uz0VAhsNOieBFUjha2QrcssGIWaL863FrZ1njiW5mBxKi8C6zRln8MSh9Fu9tpPmx+isbfonrSzRenrAHIc4+iISFTqy7q4u5cUS8OhznJ3Wc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl; spf=none smtp.mailfrom=bgdev.pl; dkim=pass (2048-bit key) header.d=bgdev-pl.20230601.gappssmtp.com header.i=@bgdev-pl.20230601.gappssmtp.com header.b=EMQivRYd; arc=none smtp.client-ip=209.85.128.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=bgdev.pl Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=bgdev.pl Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=bgdev-pl.20230601.gappssmtp.com header.i=@bgdev-pl.20230601.gappssmtp.com header.b="EMQivRYd" Received: by mail-wm1-f53.google.com with SMTP id 5b1f17b1804b1-40e7065b692so42560895e9.3 for ; Tue, 30 Jan 2024 04:48:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bgdev-pl.20230601.gappssmtp.com; s=20230601; t=1706618924; x=1707223724; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=yJQAPHnGPqj4qq3a7VK5h6sk6j09P7jLPNzWXDjdei0=; b=EMQivRYdFIPwinLzRm//CK61LyWLJpzIte7H8LNBS+ANCwrIsVaZ3ENKTWruUqSgHn y4zqRNQsrSf5QE9OVYQygu6894D0j9FURmVntQIZPh+atmyNCez/jPpbxbzKTMIEzpK3 R1RyWSKT2M5kgjCpIuxXp4rqkVFwrm+dmEGagEl9qcs85si2PwT8VZi+fksyOufn8FtX asdQhukreKwrjg/gm4pTiFEw2Fzeo2wcmwi4avriNx/X4LYyaPlOMOrbGjI+t8F8Vuya AtiiygK22Bd+qp5RrCOQRK2d1yW2smGpDGM4AeKtYg5slnNEivK6J/d2gN2ehiwUTCSm S4cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706618924; x=1707223724; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=yJQAPHnGPqj4qq3a7VK5h6sk6j09P7jLPNzWXDjdei0=; b=VpCFxDiQ6HN49sYh53kL1Zgummjc9s/A6RwvWMy5lr/zRH7rxx0U32g9hMdvjNKM0s LNaM35JQm3BT+ZEvsYXETrIAzITD8+Gj4aa7kx1jRj9IUW7Xdet3JsZpzUbNxapo4lvL ewOf++4MemzcGM6dKqGqGMdRntaI5uo0p+z+MhXad+17bPorV613UJuj70ZEAue264Cf MfYWdB3GgQGWZJKqFnTF73nTn24KgLT7QqikiSdeq3Q/DZLsKLBarmUVjMUxwcy2O5Qy YWHKlTbzgnXUsGep2IsEOPbgz5ZL0NFojs1SQOydvsmbAGdbfTvYln3vzpaipsn+YQco /6iQ== X-Gm-Message-State: AOJu0Yye5zN/FZsq3pCdpaJZGgPuOfXkI+J07mjsUmDFojltxb+FMdcN ocMAiwsGALdUp3GzbjkuCc4HNM9J9/ir5qb4QHvv1gWtfhwN5qpETXRDFpkddpg= X-Google-Smtp-Source: AGHT+IHzB67OgTxI+fcR3wK5ROr7axGVhmXy3f6vdGpTdqUd1C43aAr+F+w+9hHdNQug5OAu33joOw== X-Received: by 2002:a05:600c:5123:b0:40e:4806:f436 with SMTP id o35-20020a05600c512300b0040e4806f436mr7277977wms.3.1706618924403; Tue, 30 Jan 2024 04:48:44 -0800 (PST) Received: from brgl-uxlite.home ([2a01:cb1d:334:ac00:abc8:f77e:abeb:129c]) by smtp.gmail.com with ESMTPSA id en8-20020a056000420800b0033940016d6esm6625337wrb.93.2024.01.30.04.48.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jan 2024 04:48:44 -0800 (PST) From: Bartosz Golaszewski To: Linus Walleij , Kent Gibson , Alex Elder , Geert Uytterhoeven , "Paul E . McKenney" , Andy Shevchenko , Wolfram Sang Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski Subject: [PATCH 05/22] gpio: don't set label from irq helpers Date: Tue, 30 Jan 2024 13:48:11 +0100 Message-Id: <20240130124828.14678-6-brgl@bgdev.pl> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20240130124828.14678-1-brgl@bgdev.pl> References: <20240130124828.14678-1-brgl@bgdev.pl> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Bartosz Golaszewski We will soon serialize access to the descriptor label using SRCU. The write-side of the protection will require calling synchronize_srcu() which must not be called from atomic context. We have two irq helpers: gpiochip_lock_as_irq() and gpiochip_unlock_as_irq() that set the label if the GPIO is not requested but is being used as interrupt. They are called with a spinlock held from the interrupt subsystem. They must not do it if we are to use SRCU so instead let's move the special corner case to a dedicated getter. Let's use the flags of the descriptor to figure out whether we should use the special "interrupt" label. Signed-off-by: Bartosz Golaszewski Reviewed-by: Linus Walleij --- drivers/gpio/gpiolib.c | 21 ++++++++------------- 1 file changed, 8 insertions(+), 13 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d0a2f014dacd..4e6b26b3febb 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -107,7 +107,14 @@ static bool gpiolib_initialized; =20 const char *gpiod_get_label(struct gpio_desc *desc) { - return desc->label; + unsigned long flags; + + flags =3D READ_ONCE(desc->flags); + if (test_bit(FLAG_USED_AS_IRQ, &flags) && + !test_bit(FLAG_REQUESTED, &flags)) + return "interrupt"; + + return test_bit(FLAG_REQUESTED, &flags) ? desc->label : NULL; } =20 static inline void desc_set_label(struct gpio_desc *d, const char *label) @@ -3590,14 +3597,6 @@ int gpiochip_lock_as_irq(struct gpio_chip *gc, unsig= ned int offset) set_bit(FLAG_USED_AS_IRQ, &desc->flags); set_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); =20 - /* - * If the consumer has not set up a label (such as when the - * IRQ is referenced from .to_irq()) we set up a label here - * so it is clear this is used as an interrupt. - */ - if (!desc->label) - desc_set_label(desc, "interrupt"); - return 0; } EXPORT_SYMBOL_GPL(gpiochip_lock_as_irq); @@ -3620,10 +3619,6 @@ void gpiochip_unlock_as_irq(struct gpio_chip *gc, un= signed int offset) =20 clear_bit(FLAG_USED_AS_IRQ, &desc->flags); clear_bit(FLAG_IRQ_IS_ENABLED, &desc->flags); - - /* If we only had this marking, erase it */ - if (desc->label && !strcmp(desc->label, "interrupt")) - desc_set_label(desc, NULL); } EXPORT_SYMBOL_GPL(gpiochip_unlock_as_irq); =20 --=20 2.40.1