From: Suman Anna <s-anna@ti.com>
To: Ohad Ben-Cohen <ohad@wizery.com>,
Mark Rutland <mark.rutland@arm.com>,
Kumar Gala <galak@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>,
Josh Cartwright <joshc@codeaurora.org>,
Bjorn Andersson <bjorn@kryo.se>, <linux-kernel@vger.kernel.org>,
<linux-omap@vger.kernel.org>, <devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
Suman Anna <s-anna@ti.com>
Subject: [PATCHv5 03/15] hwspinlock/core: maintain a list of registered hwspinlock banks
Date: Wed, 30 Apr 2014 19:34:24 -0500 [thread overview]
Message-ID: <1398904476-26200-4-git-send-email-s-anna@ti.com> (raw)
In-Reply-To: <1398904476-26200-1-git-send-email-s-anna@ti.com>
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 <s-anna@ti.com>
---
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
next prev parent reply other threads:[~2014-05-01 0:35 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-01 0:34 [PATCHv5 00/15] hwspinlock/omap dt support Suman Anna
2014-05-01 0:34 ` [PATCHv5 01/15] Documentation: dt: add common bindings for hwspinlock Suman Anna
2014-05-02 14:58 ` Rob Herring
2014-05-02 22:46 ` Suman Anna
2014-05-01 0:34 ` [PATCHv5 02/15] Documentation: dt: add the omap hwspinlock bindings document Suman Anna
2014-05-01 0:34 ` Suman Anna [this message]
2014-07-01 12:26 ` [PATCHv5 03/15] hwspinlock/core: maintain a list of registered hwspinlock banks Ohad Ben-Cohen
2014-07-02 21:14 ` Suman Anna
2014-07-03 7:00 ` Ohad Ben-Cohen
2014-07-03 17:28 ` Suman Anna
2014-07-04 5:01 ` Ohad Ben-Cohen
2014-07-08 15:22 ` Suman Anna
2014-05-01 0:34 ` [PATCHv5 04/15] hwspinlock/core: add common OF helpers Suman Anna
2014-07-01 12:45 ` Ohad Ben-Cohen
2014-07-02 21:14 ` Suman Anna
2014-07-03 7:15 ` Ohad Ben-Cohen
2014-07-03 17:35 ` Suman Anna
2014-07-04 4:58 ` Ohad Ben-Cohen
2014-07-08 15:37 ` Suman Anna
2014-05-01 0:34 ` [PATCHv5 05/15] hwspinlock/omap: add support for dt nodes Suman Anna
2014-07-01 12:48 ` Ohad Ben-Cohen
2014-07-02 19:42 ` Suman Anna
2014-07-03 7:25 ` Ohad Ben-Cohen
2014-05-01 0:34 ` [PATCHv5 06/15] hwspinlock/omap: enable module before reading SYSSTATUS register Suman Anna
2014-07-01 12:51 ` Ohad Ben-Cohen
2014-07-02 19:38 ` Suman Anna
2014-05-01 0:34 ` [PATCHv5 07/15] hwspinlock/omap: enable build for AM33xx, AM43xx & DRA7xx Suman Anna
2014-07-01 12:53 ` Ohad Ben-Cohen
2014-05-01 0:34 ` [PATCHv5 RFC 08/15] hwspinlock/core: add support for base id in DT Suman Anna
2014-05-05 20:37 ` Rob Herring
2014-05-05 21:37 ` Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 09/15] hwspinlock/core: prepare unregister code to support reserved locks Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 10/15] hwspinlock/core: prepare core " Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 11/15] hwspinlock/core: add support for " Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 12/15] hwspinlock/core: add OF helper to parse " Suman Anna
2014-05-05 21:44 ` Suman Anna
2014-05-05 21:54 ` Josh Cartwright
2014-05-10 1:17 ` Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 13/15] hwspinlock/omap: use OF helper to get " Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 14/15] hwspinlock/core: return ERR_PTRs on failure in _request_ api Suman Anna
2014-05-01 0:34 ` [PATCHv5 RFC 15/15] hwspinlock/core: change return codes of_hwspin_lock_request_specific Suman Anna
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