From mboxrd@z Thu Jan 1 00:00:00 1970 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 27380635; Thu, 5 Sep 2024 09:49:48 +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=1725529788; cv=none; b=tziKCZcV8P/TEXGvzKF99JHRP6yedE3jCEscLjovwbygxKb854ls/cBhvJTadW2yXmdsbyIhGu9DOPDWFlTAK/oIqMkuchRGsgiNDxueuBIFhfX3fwex0dYV1daIvUm0Yj8skCoqrwFgfIvlMQf6s7ZbZt2KdYvk9qCnaTJpbwM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725529788; c=relaxed/simple; bh=LSUrCYBnbUD+va0v5j+4JC9Touqq8G8AC0zGGjgWU5Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SUFs0AnetR0kDBYEQ2DGYfbe/wbAGoFMGXEs5SeumSUxCNDScxHg7G7Vtm/WWnhe0K6KJzhIUobKLTThzQ5wIbv3wm5KvJSmZwF1bLABW81wRkdKsMgLvByE/0YTQZ65hK5kUlyaefnxYurPv/egbiQ83bfRXCZnIvDU3KaXIcU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=lFqXjirV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="lFqXjirV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 88E0DC4CEC3; Thu, 5 Sep 2024 09:49:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1725529788; bh=LSUrCYBnbUD+va0v5j+4JC9Touqq8G8AC0zGGjgWU5Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lFqXjirVbRuuT1GJg/hQjvQDhW2xKhbX00V8PImFZ3x4ea9bRxzReeCsh1OMeOsN9 xNJsyDFESa7mHinjoxq7bAerqXqBUvz9fsS9vJWO6p1a+DNyfz8R7wgVgdC+kXe/c+ 1G2Vf6nAwxh+cYdRI9pnojllTqVhbe0EYV8MOFV4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Richard Maina , Bjorn Andersson , Chris Lew , Sasha Levin Subject: [PATCH 6.10 125/184] hwspinlock: Introduce hwspin_lock_bust() Date: Thu, 5 Sep 2024 11:40:38 +0200 Message-ID: <20240905093737.107835101@linuxfoundation.org> X-Mailer: git-send-email 2.46.0 In-Reply-To: <20240905093732.239411633@linuxfoundation.org> References: <20240905093732.239411633@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Richard Maina [ Upstream commit 7c327d56597d8de1680cf24e956b704270d3d84a ] When a remoteproc crashes or goes down unexpectedly this can result in a state where locks held by the remoteproc will remain locked possibly resulting in deadlock. This new API hwspin_lock_bust() allows hwspinlock implementers to define a bust operation for freeing previously acquired hwspinlocks after verifying ownership of the acquired lock. Signed-off-by: Richard Maina Reviewed-by: Bjorn Andersson Signed-off-by: Chris Lew Link: https://lore.kernel.org/r/20240529-hwspinlock-bust-v3-1-c8b924ffa5a2@quicinc.com Signed-off-by: Bjorn Andersson Signed-off-by: Sasha Levin --- Documentation/locking/hwspinlock.rst | 11 ++++++++++ drivers/hwspinlock/hwspinlock_core.c | 28 ++++++++++++++++++++++++ drivers/hwspinlock/hwspinlock_internal.h | 3 +++ include/linux/hwspinlock.h | 6 +++++ 4 files changed, 48 insertions(+) diff --git a/Documentation/locking/hwspinlock.rst b/Documentation/locking/hwspinlock.rst index 6f03713b7003..2ffaa3cbd63f 100644 --- a/Documentation/locking/hwspinlock.rst +++ b/Documentation/locking/hwspinlock.rst @@ -85,6 +85,17 @@ is already free). Should be called from a process context (might sleep). +:: + + int hwspin_lock_bust(struct hwspinlock *hwlock, unsigned int id); + +After verifying the owner of the hwspinlock, release a previously acquired +hwspinlock; returns 0 on success, or an appropriate error code on failure +(e.g. -EOPNOTSUPP if the bust operation is not defined for the specific +hwspinlock). + +Should be called from a process context (might sleep). + :: int hwspin_lock_timeout(struct hwspinlock *hwlock, unsigned int timeout); diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 0c0a932c00f3..6505261e6068 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -305,6 +305,34 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) } EXPORT_SYMBOL_GPL(__hwspin_unlock); +/** + * hwspin_lock_bust() - bust a specific hwspinlock + * @hwlock: a previously-acquired hwspinlock which we want to bust + * @id: identifier of the remote lock holder, if applicable + * + * This function will bust a hwspinlock that was previously acquired as + * long as the current owner of the lock matches the id given by the caller. + * + * Context: Process context. + * + * Returns: 0 on success, or -EINVAL if the hwspinlock does not exist, or + * the bust operation fails, and -EOPNOTSUPP if the bust operation is not + * defined for the hwspinlock. + */ +int hwspin_lock_bust(struct hwspinlock *hwlock, unsigned int id) +{ + if (WARN_ON(!hwlock)) + return -EINVAL; + + if (!hwlock->bank->ops->bust) { + pr_err("bust operation not defined\n"); + return -EOPNOTSUPP; + } + + return hwlock->bank->ops->bust(hwlock, id); +} +EXPORT_SYMBOL_GPL(hwspin_lock_bust); + /** * of_hwspin_lock_simple_xlate - translate hwlock_spec to return a lock id * @hwlock_spec: hwlock specifier as found in the device tree diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h index 29892767bb7a..f298fc0ee5ad 100644 --- a/drivers/hwspinlock/hwspinlock_internal.h +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -21,6 +21,8 @@ struct hwspinlock_device; * @trylock: make a single attempt to take the lock. returns 0 on * failure and true on success. may _not_ sleep. * @unlock: release the lock. always succeed. may _not_ sleep. + * @bust: optional, platform-specific bust handler, called by hwspinlock + * core to bust a specific lock. * @relax: optional, platform-specific relax handler, called by hwspinlock * core while spinning on a lock, between two successive * invocations of @trylock. may _not_ sleep. @@ -28,6 +30,7 @@ struct hwspinlock_device; struct hwspinlock_ops { int (*trylock)(struct hwspinlock *lock); void (*unlock)(struct hwspinlock *lock); + int (*bust)(struct hwspinlock *lock, unsigned int id); void (*relax)(struct hwspinlock *lock); }; diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h index bfe7c1f1ac6d..f0231dbc4777 100644 --- a/include/linux/hwspinlock.h +++ b/include/linux/hwspinlock.h @@ -68,6 +68,7 @@ int __hwspin_lock_timeout(struct hwspinlock *, unsigned int, int, int __hwspin_trylock(struct hwspinlock *, int, unsigned long *); void __hwspin_unlock(struct hwspinlock *, int, unsigned long *); int of_hwspin_lock_get_id_byname(struct device_node *np, const char *name); +int hwspin_lock_bust(struct hwspinlock *hwlock, unsigned int id); int devm_hwspin_lock_free(struct device *dev, struct hwspinlock *hwlock); struct hwspinlock *devm_hwspin_lock_request(struct device *dev); struct hwspinlock *devm_hwspin_lock_request_specific(struct device *dev, @@ -127,6 +128,11 @@ void __hwspin_unlock(struct hwspinlock *hwlock, int mode, unsigned long *flags) { } +static inline int hwspin_lock_bust(struct hwspinlock *hwlock, unsigned int id) +{ + return 0; +} + static inline int of_hwspin_lock_get_id(struct device_node *np, int index) { return 0; -- 2.43.0