From nobody Sun Feb 8 14:10:22 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 EC70E36C0B4; Tue, 3 Feb 2026 06:12:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770099133; cv=none; b=gwVAJK66SnYJCpUbHyiWB1dtsx4AETzWFNXpC68kwoOSZZAY9gQ340F3sbuiZh61mdn4oP8YfWKe9z4iWulbi5zC2igUOKBOQ0Na17v++2M0/+LWtLgCR71YmZx71M9z677w22/icbc6TATur7Gu7LYBcKv8bVqayBgaEyxN3N4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770099133; c=relaxed/simple; bh=yQiJynIAbuFeeRMS6x1JyTsW8237/zPmWVWr/0DAPzU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=t9mHp3tFuuS5P2AuilrSS/pNGTlg8rngx7b57t5+b38z/cBctKZY/akKHN+8KuNqdiMetYjtDjV1VsZ4O0ecieic64iVvQ0fwspFbVXQzjmXIz8tcxPc9iWiAGPUK4o5KrwgFfpGbz0OaABGlwK8J0gAGp16tz5IHoywAgPNyY4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oNxCY7OD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oNxCY7OD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19089C116D0; Tue, 3 Feb 2026 06:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770099132; bh=yQiJynIAbuFeeRMS6x1JyTsW8237/zPmWVWr/0DAPzU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oNxCY7OD/rcNlfOqxqyeEKrKEjgKPwe2bzveNeFWKBcmaxeVr4CsM87UPeZN8IUtW poPT581dLhXD++sPmqr4Ng9yw0rTmb7XKWhYF0T/Qi5Mda12glpmxKX5bWrENR8f5/ 3PdttxuXXSUhQfGoeZiS4+uB+Xg3j1R1agqlsM7O8EFMpfTGqvWKOrDUlwPQhsPQyv 4kPrVDIXukCYhTx0wLs4CKPfkxdgN0Pi68PabF2Lh+y/gTqoD8Fu+xC4MbOf66WuoR 7xj1ZEEsuZPFbFwhqAIX9v49ZXctKdZWRoUhMFTqXxmWgZyocpiOjh0gnzdm4VR7V9 f3g7qJgRnocaA== From: Tzung-Bi Shih To: Greg Kroah-Hartman , "Rafael J. Wysocki" , Danilo Krummrich , Bartosz Golaszewski , Linus Walleij Cc: Jonathan Corbet , Shuah Khan , Laurent Pinchart , Wolfram Sang , Jason Gunthorpe , Johan Hovold , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, chrome-platform@lists.linux.dev, tzungbi@kernel.org, Dan Williams , linux-gpio@vger.kernel.org Subject: [PATCH v2 08/11] gpio: cdev: Leverage revocable for accessing struct gpio_chip Date: Tue, 3 Feb 2026 06:10:55 +0000 Message-ID: <20260203061059.975605-9-tzungbi@kernel.org> X-Mailer: git-send-email 2.53.0.rc2.204.g2597b5adb4-goog In-Reply-To: <20260203061059.975605-1-tzungbi@kernel.org> References: <20260203061059.975605-1-tzungbi@kernel.org> 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" Struct gpio_device now provides a revocable provider to the underlying struct gpio_chip. Leverage revocable for accessing the struct gpio_chip. Signed-off-by: Tzung-Bi Shih --- v2: - Change usages accordingly after applying https://lore.kernel.org/all/20260129143733.45618-4-tzungbi@kernel.org. - Preserve a local storage for `struct revocable`. - Combine multiple patches (see "v1:"). v1: - https://lore.kernel.org/all/20260116081036.352286-14-tzungbi@kernel.org - https://lore.kernel.org/all/20260116081036.352286-15-tzungbi@kernel.org - https://lore.kernel.org/all/20260116081036.352286-16-tzungbi@kernel.org - https://lore.kernel.org/all/20260116081036.352286-17-tzungbi@kernel.org - https://lore.kernel.org/all/20260116081036.352286-18-tzungbi@kernel.org drivers/gpio/gpiolib-cdev.c | 70 ++++++++++++++++++------------------- 1 file changed, 34 insertions(+), 36 deletions(-) diff --git a/drivers/gpio/gpiolib-cdev.c b/drivers/gpio/gpiolib-cdev.c index aaa5de814468..ca9c04765df4 100644 --- a/drivers/gpio/gpiolib-cdev.c +++ b/drivers/gpio/gpiolib-cdev.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -210,10 +211,10 @@ static long linehandle_ioctl(struct file *file, unsig= ned int cmd, DECLARE_BITMAP(vals, GPIOHANDLES_MAX); unsigned int i; int ret; + struct gpio_chip *gc; =20 - guard(srcu)(&lh->gdev->srcu); - - if (!rcu_access_pointer(lh->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lh->gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 switch (cmd) { @@ -1432,10 +1433,10 @@ static long linereq_ioctl(struct file *file, unsign= ed int cmd, { struct linereq *lr =3D file->private_data; void __user *ip =3D (void __user *)arg; + struct gpio_chip *gc; =20 - guard(srcu)(&lr->gdev->srcu); - - if (!rcu_access_pointer(lr->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lr->gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 switch (cmd) { @@ -1463,10 +1464,10 @@ static __poll_t linereq_poll(struct file *file, { struct linereq *lr =3D file->private_data; __poll_t events =3D 0; + struct gpio_chip *gc; =20 - guard(srcu)(&lr->gdev->srcu); - - if (!rcu_access_pointer(lr->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lr->gdev->chip_rp, gc); + if (!gc) return EPOLLHUP | EPOLLERR; =20 poll_wait(file, &lr->wait, wait); @@ -1485,10 +1486,10 @@ static ssize_t linereq_read(struct file *file, char= __user *buf, struct gpio_v2_line_event le; ssize_t bytes_read =3D 0; int ret; + struct gpio_chip *gc; =20 - guard(srcu)(&lr->gdev->srcu); - - if (!rcu_access_pointer(lr->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(lr->gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 if (count < sizeof(le)) @@ -1781,10 +1782,10 @@ static __poll_t lineevent_poll(struct file *file, { struct lineevent_state *le =3D file->private_data; __poll_t events =3D 0; + struct gpio_chip *gc; =20 - guard(srcu)(&le->gdev->srcu); - - if (!rcu_access_pointer(le->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(le->gdev->chip_rp, gc); + if (!gc) return EPOLLHUP | EPOLLERR; =20 poll_wait(file, &le->wait, wait); @@ -1819,10 +1820,10 @@ static ssize_t lineevent_read(struct file *file, ch= ar __user *buf, ssize_t bytes_read =3D 0; ssize_t ge_size; int ret; + struct gpio_chip *gc; =20 - guard(srcu)(&le->gdev->srcu); - - if (!rcu_access_pointer(le->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(le->gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 /* @@ -1901,10 +1902,10 @@ static long lineevent_ioctl(struct file *file, unsi= gned int cmd, struct lineevent_state *le =3D file->private_data; void __user *ip =3D (void __user *)arg; struct gpiohandle_data ghd; + struct gpio_chip *gc; =20 - guard(srcu)(&le->gdev->srcu); - - if (!rcu_access_pointer(le->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(le->gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 /* @@ -2434,11 +2435,11 @@ static long gpio_ioctl(struct file *file, unsigned = int cmd, unsigned long arg) struct gpio_chardev_data *cdev =3D file->private_data; struct gpio_device *gdev =3D cdev->gdev; void __user *ip =3D (void __user *)arg; - - guard(srcu)(&gdev->srcu); + struct gpio_chip *gc; =20 /* We fail any subsequent ioctl():s when the chip is gone */ - if (!rcu_access_pointer(gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 /* Fill in the struct and pass to userspace */ @@ -2497,12 +2498,9 @@ static void lineinfo_changed_func(struct work_struct= *work) * Pin functions are in general much more static and while it's * not 100% bullet-proof, it's good enough for most cases. */ - scoped_guard(srcu, &ctx->gdev->srcu) { - gc =3D srcu_dereference(ctx->gdev->chip, &ctx->gdev->srcu); - if (gc && - !pinctrl_gpio_can_use_line(gc, ctx->chg.info.offset)) - ctx->chg.info.flags |=3D GPIO_V2_LINE_FLAG_USED; - } + REVOCABLE_TRY_ACCESS_WITH(ctx->gdev->chip_rp, gc); + if (gc && !pinctrl_gpio_can_use_line(gc, ctx->chg.info.offset)) + ctx->chg.info.flags |=3D GPIO_V2_LINE_FLAG_USED; } =20 ret =3D kfifo_in_spinlocked(&ctx->cdev->events, &ctx->chg, 1, @@ -2583,10 +2581,10 @@ static __poll_t lineinfo_watch_poll(struct file *fi= le, { struct gpio_chardev_data *cdev =3D file->private_data; __poll_t events =3D 0; + struct gpio_chip *gc; =20 - guard(srcu)(&cdev->gdev->srcu); - - if (!rcu_access_pointer(cdev->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(cdev->gdev->chip_rp, gc); + if (!gc) return EPOLLHUP | EPOLLERR; =20 poll_wait(file, &cdev->wait, pollt); @@ -2606,10 +2604,10 @@ static ssize_t lineinfo_watch_read(struct file *fil= e, char __user *buf, ssize_t bytes_read =3D 0; int ret; size_t event_size; + struct gpio_chip *gc; =20 - guard(srcu)(&cdev->gdev->srcu); - - if (!rcu_access_pointer(cdev->gdev->chip)) + REVOCABLE_TRY_ACCESS_WITH(cdev->gdev->chip_rp, gc); + if (!gc) return -ENODEV; =20 #ifndef CONFIG_GPIO_CDEV_V1 --=20 2.53.0.rc2.204.g2597b5adb4-goog