Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752069AbaEAAfp (ORCPT ); Wed, 30 Apr 2014 20:35:45 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:51348 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751869AbaEAAfm (ORCPT ); Wed, 30 Apr 2014 20:35:42 -0400 From: Suman Anna To: Ohad Ben-Cohen , Mark Rutland , Kumar Gala CC: Tony Lindgren , Josh Cartwright , Bjorn Andersson , , , , , Suman Anna Subject: [PATCHv5 03/15] hwspinlock/core: maintain a list of registered hwspinlock banks Date: Wed, 30 Apr 2014 19:34:24 -0500 Message-ID: <1398904476-26200-4-git-send-email-s-anna@ti.com> X-Mailer: git-send-email 1.9.2 In-Reply-To: <1398904476-26200-1-git-send-email-s-anna@ti.com> References: <1398904476-26200-1-git-send-email-s-anna@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The hwspinlock_device structure is used for registering a bank of locks with the driver core. The structure already contains the necessary members to identify the bank of locks. The core does not maintain the hwspinlock_devices itself, but maintains only a radix tree for all the registered locks. A specific lock can be requested by users using a global lock id, and any device-specific fields can be retrieved through a reference to the hwspinlock_device in each lock. The global lock id, however, is not friendly to be requested for users using the device-tree model. The device-tree representation will typically have each of the hwspinlock devices represented as a DT node, and a specific lock can be requested using the device's phandle and a lock specifier. Add support to the core therefore to maintain all the registered hwspinlock_devices, so that a device can be looked up and a specific lock belonging to the device requested through a phandle + args approach. Signed-off-by: Suman Anna --- Documentation/hwspinlock.txt | 2 ++ drivers/hwspinlock/hwspinlock_core.c | 51 ++++++++++++++++++++++++++++++++ drivers/hwspinlock/hwspinlock_internal.h | 2 ++ 3 files changed, 55 insertions(+) diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt index 62f7d4e..640ae47 100644 --- a/Documentation/hwspinlock.txt +++ b/Documentation/hwspinlock.txt @@ -251,6 +251,7 @@ implementation using the hwspin_lock_register() API. /** * struct hwspinlock_device - a device which usually spans numerous hwspinlocks + * @list: list element to link hwspinlock devices together * @dev: underlying device, will be used to invoke runtime PM api * @ops: platform-specific hwspinlock handlers * @base_id: id index of the first lock in this device @@ -258,6 +259,7 @@ implementation using the hwspin_lock_register() API. * @lock: dynamically allocated array of 'struct hwspinlock' */ struct hwspinlock_device { + struct list_head list; struct device *dev; const struct hwspinlock_ops *ops; int base_id; diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c index 461a0d7..48f7866 100644 --- a/drivers/hwspinlock/hwspinlock_core.c +++ b/drivers/hwspinlock/hwspinlock_core.c @@ -59,6 +59,11 @@ static RADIX_TREE(hwspinlock_tree, GFP_KERNEL); */ static DEFINE_MUTEX(hwspinlock_tree_lock); +/* + * A linked list for maintaining all the registered hwspinlock devices. + * The list is maintained in an ordered-list of the supported locks group. + */ +static LIST_HEAD(hwspinlock_devices); /** * __hwspin_trylock() - attempt to lock a specific hwspinlock @@ -307,6 +312,40 @@ out: return hwlock; } +/* + * Add a new hwspinlock device to the global list, keeping the list of + * devices sorted by base order. + * + * Returns 0 on success, or -EBUSY if the new device overlaps with some + * other device's lock space. + */ +static int hwspinlock_device_add(struct hwspinlock_device *bank) +{ + struct list_head *entry = &hwspinlock_devices; + struct hwspinlock_device *_bank; + int ret = 0; + + list_for_each(entry, &hwspinlock_devices) { + _bank = list_entry(entry, struct hwspinlock_device, list); + if (_bank->base_id >= bank->base_id + bank->num_locks) + break; + } + + if (entry != &hwspinlock_devices && + entry->prev != &hwspinlock_devices) { + _bank = list_entry(entry->prev, struct hwspinlock_device, list); + if (_bank->base_id + _bank->num_locks > bank->base_id) { + dev_err(bank->dev, "hwlock space overlap, cannot add device\n"); + ret = -EBUSY; + } + } + + if (!ret) + list_add_tail(&bank->list, entry); + + return ret; +} + /** * hwspin_lock_register() - register a new hw spinlock device * @bank: the hwspinlock device, which usually provides numerous hw locks @@ -339,6 +378,12 @@ int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, bank->base_id = base_id; bank->num_locks = num_locks; + mutex_lock(&hwspinlock_tree_lock); + ret = hwspinlock_device_add(bank); + mutex_unlock(&hwspinlock_tree_lock); + if (ret) + return ret; + for (i = 0; i < num_locks; i++) { hwlock = &bank->lock[i]; @@ -355,6 +400,9 @@ int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, reg_failed: while (--i >= 0) hwspin_lock_unregister_single(base_id + i); + mutex_lock(&hwspinlock_tree_lock); + list_del(&bank->list); + mutex_unlock(&hwspinlock_tree_lock); return ret; } EXPORT_SYMBOL_GPL(hwspin_lock_register); @@ -386,6 +434,9 @@ int hwspin_lock_unregister(struct hwspinlock_device *bank) WARN_ON(tmp != hwlock); } + mutex_lock(&hwspinlock_tree_lock); + list_del(&bank->list); + mutex_unlock(&hwspinlock_tree_lock); return 0; } EXPORT_SYMBOL_GPL(hwspin_lock_unregister); diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h index d26f78b..aff560c 100644 --- a/drivers/hwspinlock/hwspinlock_internal.h +++ b/drivers/hwspinlock/hwspinlock_internal.h @@ -53,6 +53,7 @@ struct hwspinlock { /** * struct hwspinlock_device - a device which usually spans numerous hwspinlocks + * @list: list element to link hwspinlock devices together * @dev: underlying device, will be used to invoke runtime PM api * @ops: platform-specific hwspinlock handlers * @base_id: id index of the first lock in this device @@ -60,6 +61,7 @@ struct hwspinlock { * @lock: dynamically allocated array of 'struct hwspinlock' */ struct hwspinlock_device { + struct list_head list; struct device *dev; const struct hwspinlock_ops *ops; int base_id; -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/