diff options
Diffstat (limited to 'drivers/dca')
| -rw-r--r-- | drivers/dca/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/dca/Makefile | 2 | ||||
| -rw-r--r-- | drivers/dca/dca-core.c | 200 | ||||
| -rw-r--r-- | drivers/dca/dca-sysfs.c | 88 |
4 files changed, 301 insertions, 0 deletions
diff --git a/drivers/dca/Kconfig b/drivers/dca/Kconfig new file mode 100644 index 000000000000..e2f7436da051 --- /dev/null +++ b/drivers/dca/Kconfig @@ -0,0 +1,11 @@ +# +# DCA server configuration +# + +config DCA + tristate "DCA support for clients and providers" + default m + help + This is a server to help modules that want to use Direct Cache + Access to find DCA providers that will supply correct CPU tags. + diff --git a/drivers/dca/Makefile b/drivers/dca/Makefile new file mode 100644 index 000000000000..b2db56bb9dde --- /dev/null +++ b/drivers/dca/Makefile @@ -0,0 +1,2 @@ +obj-$(CONFIG_DCA) += dca.o +dca-objs := dca-core.o dca-sysfs.o diff --git a/drivers/dca/dca-core.c b/drivers/dca/dca-core.c new file mode 100644 index 000000000000..bf5b92f86df7 --- /dev/null +++ b/drivers/dca/dca-core.c @@ -0,0 +1,200 @@ +/* + * Copyright(c) 2007 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * The full GNU General Public License is included in this distribution in the + * file called COPYING. + */ + +/* + * This driver supports an interface for DCA clients and providers to meet. + */ + +#include <linux/kernel.h> +#include <linux/notifier.h> +#include <linux/device.h> +#include <linux/dca.h> + +MODULE_LICENSE("GPL"); + +/* For now we're assuming a single, global, DCA provider for the system. */ + +static DEFINE_SPINLOCK(dca_lock); + +static struct dca_provider *global_dca = NULL; + +/** + * dca_add_requester - add a dca client to the list + * @dev - the device that wants dca service + */ +int dca_add_requester(struct device *dev) +{ + int err, slot; + + if (!global_dca) + return -ENODEV; + + spin_lock(&dca_lock); + slot = global_dca->ops->add_requester(global_dca, dev); + spin_unlock(&dca_lock); + if (slot < 0) + return slot; + + err = dca_sysfs_add_req(global_dca, dev, slot); + if (err) { + spin_lock(&dca_lock); + global_dca->ops->remove_requester(global_dca, dev); + spin_unlock(&dca_lock); + return err; + } + + return 0; +} +EXPORT_SYMBOL_GPL(dca_add_requester); + +/** + * dca_remove_requester - remove a dca client from the list + * @dev - the device that wants dca service + */ +int dca_remove_requester(struct device *dev) +{ + int slot; + if (!global_dca) + return -ENODEV; + + spin_lock(&dca_lock); + slot = global_dca->ops->remove_requester(global_dca, dev); + spin_unlock(&dca_lock); + if (slot < 0) + return slot; + + dca_sysfs_remove_req(global_dca, slot); + return 0; +} +EXPORT_SYMBOL_GPL(dca_remove_requester); + +/** + * dca_get_tag - return the dca tag for the given cpu + * @cpu - the cpuid as returned by get_cpu() + */ +u8 dca_get_tag(int cpu) +{ + if (!global_dca) + return -ENODEV; + return global_dca->ops->get_tag(global_dca, cpu); +} +EXPORT_SYMBOL_GPL(dca_get_tag); + +/** + * alloc_dca_provider - get data struct for describing a dca provider + * @ops - pointer to struct of dca operation function pointers + * @priv_size - size of extra mem to be added for provider's needs + */ +struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size) +{ + struct dca_provider *dca; + int alloc_size; + + alloc_size = (sizeof(*dca) + priv_size); + dca = kzalloc(alloc_size, GFP_KERNEL); + if (!dca) + return NULL; + dca->ops = ops; + + return dca; +} +EXPORT_SYMBOL_GPL(alloc_dca_provider); + +/** + * free_dca_provider - release the dca provider data struct + * @ops - pointer to struct of dca operation function pointers + * @priv_size - size of extra mem to be added for provider's needs + */ +void free_dca_provider(struct dca_provider *dca) +{ + kfree(dca); +} +EXPORT_SYMBOL_GPL(free_dca_provider); + +static BLOCKING_NOTIFIER_HEAD(dca_provider_chain); + +/** + * register_dca_provider - register a dca provider + * @dca - struct created by alloc_dca_provider() + * @dev - device providing dca services + */ +int register_dca_provider(struct dca_provider *dca, struct device *dev) +{ + int err; + + if (global_dca) + return -EEXIST; + err = dca_sysfs_add_provider(dca, dev); + if (err) + return err; + global_dca = dca; + blocking_notifier_call_chain(&dca_provider_chain, + DCA_PROVIDER_ADD, NULL); + return 0; +} +EXPORT_SYMBOL_GPL(register_dca_provider); + +/** + * unregister_dca_provider - remove a dca provider + * @dca - struct created by alloc_dca_provider() + */ +void unregister_dca_provider(struct dca_provider *dca) +{ + if (!global_dca) + return; + blocking_notifier_call_chain(&dca_provider_chain, + DCA_PROVIDER_REMOVE, NULL); + global_dca = NULL; + dca_sysfs_remove_provider(dca); +} +EXPORT_SYMBOL_GPL(unregister_dca_provider); + +/** + * dca_register_notify - register a client's notifier callback + */ +void dca_register_notify(struct notifier_block *nb) +{ + blocking_notifier_chain_register(&dca_provider_chain, nb); +} +EXPORT_SYMBOL_GPL(dca_register_notify); + +/** + * dca_unregister_notify - remove a client's notifier callback + */ +void dca_unregister_notify(struct notifier_block *nb) +{ + blocking_notifier_chain_unregister(&dca_provider_chain, nb); +} +EXPORT_SYMBOL_GPL(dca_unregister_notify); + +static int __init dca_init(void) +{ + return dca_sysfs_init(); +} + +static void __exit dca_exit(void) +{ + dca_sysfs_exit(); +} + +module_init(dca_init); +module_exit(dca_exit); + diff --git a/drivers/dca/dca-sysfs.c b/drivers/dca/dca-sysfs.c new file mode 100644 index 000000000000..24a263b6844c --- /dev/null +++ b/drivers/dca/dca-sysfs.c @@ -0,0 +1,88 @@ +#include <linux/kernel.h> +#include <linux/spinlock.h> +#include <linux/device.h> +#include <linux/idr.h> +#include <linux/kdev_t.h> +#include <linux/err.h> +#include <linux/dca.h> + +static struct class *dca_class; +static struct idr dca_idr; +static spinlock_t dca_idr_lock; + +int dca_sysfs_add_req(struct dca_provider *dca, struct device *dev, int slot) +{ + struct class_device *cd; + + cd = class_device_create(dca_class, dca->cd, MKDEV(0, slot + 1), + dev, "requester%d", slot); + if (IS_ERR(cd)) + return PTR_ERR(cd); + return 0; +} + +void dca_sysfs_remove_req(struct dca_provider *dca, int slot) +{ + class_device_destroy(dca_class, MKDEV(0, slot + 1)); +} + +int dca_sysfs_add_provider(struct dca_provider *dca, struct device *dev) +{ + struct class_device *cd; + int err = 0; + +idr_try_again: + if (!idr_pre_get(&dca_idr, GFP_KERNEL)) + return -ENOMEM; + spin_lock(&dca_idr_lock); + err = idr_get_new(&dca_idr, dca, &dca->id); + spin_unlock(&dca_idr_lock); + switch (err) { + case 0: + break; + case -EAGAIN: + goto idr_try_again; + default: + return err; + } + + cd = class_device_create(dca_class, NULL, MKDEV(0, 0), + dev, "dca%d", dca->id); + if (IS_ERR(cd)) { + spin_lock(&dca_idr_lock); + idr_remove(&dca_idr, dca->id); + spin_unlock(&dca_idr_lock); + return PTR_ERR(cd); + } + dca->cd = cd; + return 0; +} + +void dca_sysfs_remove_provider(struct dca_provider *dca) +{ + class_device_unregister(dca->cd); + dca->cd = NULL; + spin_lock(&dca_idr_lock); + idr_remove(&dca_idr, dca->id); + spin_unlock(&dca_idr_lock); +} + +int __init dca_sysfs_init(void) +{ + idr_init(&dca_idr); + spin_lock_init(&dca_idr_lock); + + dca_class = class_create(THIS_MODULE, "dca"); + if (IS_ERR(dca_class)) { + idr_destroy(&dca_idr); + return PTR_ERR(dca_class); + } + return 0; +} + +void __exit dca_sysfs_exit(void) +{ + class_destroy(dca_class); + idr_destroy(&dca_idr); +} + |