linux/drivers/dca/dca-core.c

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/*
* Copyright(c) 2007 - 2009 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>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 09:04:11 +01:00
#include <linux/slab.h>
#define DCA_VERSION "1.12.1"
MODULE_VERSION(DCA_VERSION);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Intel Corporation");
static DEFINE_SPINLOCK(dca_lock);
static LIST_HEAD(dca_domains);
static struct pci_bus *dca_pci_rc_from_dev(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
struct pci_bus *bus = pdev->bus;
while (bus->parent)
bus = bus->parent;
return bus;
}
static struct dca_domain *dca_allocate_domain(struct pci_bus *rc)
{
struct dca_domain *domain;
domain = kzalloc(sizeof(*domain), GFP_NOWAIT);
if (!domain)
return NULL;
INIT_LIST_HEAD(&domain->dca_providers);
domain->pci_rc = rc;
return domain;
}
static void dca_free_domain(struct dca_domain *domain)
{
list_del(&domain->node);
kfree(domain);
}
static struct dca_domain *dca_find_domain(struct pci_bus *rc)
{
struct dca_domain *domain;
list_for_each_entry(domain, &dca_domains, node)
if (domain->pci_rc == rc)
return domain;
return NULL;
}
static struct dca_domain *dca_get_domain(struct device *dev)
{
struct pci_bus *rc;
struct dca_domain *domain;
rc = dca_pci_rc_from_dev(dev);
domain = dca_find_domain(rc);
if (!domain) {
domain = dca_allocate_domain(rc);
if (domain)
list_add(&domain->node, &dca_domains);
}
return domain;
}
static struct dca_provider *dca_find_provider_by_dev(struct device *dev)
{
struct dca_provider *dca;
struct pci_bus *rc;
struct dca_domain *domain;
if (dev) {
rc = dca_pci_rc_from_dev(dev);
domain = dca_find_domain(rc);
if (!domain)
return NULL;
} else {
if (!list_empty(&dca_domains))
domain = list_first_entry(&dca_domains,
struct dca_domain,
node);
else
return NULL;
}
list_for_each_entry(dca, &domain->dca_providers, node)
if ((!dev) || (dca->ops->dev_managed(dca, dev)))
return dca;
return 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)
{
struct dca_provider *dca;
int err, slot = -ENODEV;
unsigned long flags;
struct pci_bus *pci_rc;
struct dca_domain *domain;
if (!dev)
return -EFAULT;
spin_lock_irqsave(&dca_lock, flags);
/* check if the requester has not been added already */
dca = dca_find_provider_by_dev(dev);
if (dca) {
spin_unlock_irqrestore(&dca_lock, flags);
return -EEXIST;
}
pci_rc = dca_pci_rc_from_dev(dev);
domain = dca_find_domain(pci_rc);
if (!domain) {
spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
list_for_each_entry(dca, &domain->dca_providers, node) {
slot = dca->ops->add_requester(dca, dev);
if (slot >= 0)
break;
}
spin_unlock_irqrestore(&dca_lock, flags);
if (slot < 0)
return slot;
err = dca_sysfs_add_req(dca, dev, slot);
if (err) {
spin_lock_irqsave(&dca_lock, flags);
if (dca == dca_find_provider_by_dev(dev))
dca->ops->remove_requester(dca, dev);
spin_unlock_irqrestore(&dca_lock, flags);
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)
{
struct dca_provider *dca;
int slot;
unsigned long flags;
if (!dev)
return -EFAULT;
spin_lock_irqsave(&dca_lock, flags);
dca = dca_find_provider_by_dev(dev);
if (!dca) {
spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
slot = dca->ops->remove_requester(dca, dev);
spin_unlock_irqrestore(&dca_lock, flags);
if (slot < 0)
return slot;
dca_sysfs_remove_req(dca, slot);
return 0;
}
EXPORT_SYMBOL_GPL(dca_remove_requester);
/**
* dca_common_get_tag - return the dca tag (serves both new and old api)
* @dev - the device that wants dca service
* @cpu - the cpuid as returned by get_cpu()
*/
u8 dca_common_get_tag(struct device *dev, int cpu)
{
struct dca_provider *dca;
u8 tag;
unsigned long flags;
spin_lock_irqsave(&dca_lock, flags);
dca = dca_find_provider_by_dev(dev);
if (!dca) {
spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
tag = dca->ops->get_tag(dca, dev, cpu);
spin_unlock_irqrestore(&dca_lock, flags);
return tag;
}
/**
* dca3_get_tag - return the dca tag to the requester device
* for the given cpu (new api)
* @dev - the device that wants dca service
* @cpu - the cpuid as returned by get_cpu()
*/
u8 dca3_get_tag(struct device *dev, int cpu)
{
if (!dev)
return -EFAULT;
return dca_common_get_tag(dev, cpu);
}
EXPORT_SYMBOL_GPL(dca3_get_tag);
/**
* dca_get_tag - return the dca tag for the given cpu (old api)
* @cpu - the cpuid as returned by get_cpu()
*/
u8 dca_get_tag(int cpu)
{
struct device *dev = NULL;
return dca_common_get_tag(dev, 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;
unsigned long flags;
struct dca_domain *domain;
err = dca_sysfs_add_provider(dca, dev);
if (err)
return err;
spin_lock_irqsave(&dca_lock, flags);
domain = dca_get_domain(dev);
if (!domain) {
spin_unlock_irqrestore(&dca_lock, flags);
return -ENODEV;
}
list_add(&dca->node, &domain->dca_providers);
spin_unlock_irqrestore(&dca_lock, flags);
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, struct device *dev)
{
unsigned long flags;
struct pci_bus *pci_rc;
struct dca_domain *domain;
blocking_notifier_call_chain(&dca_provider_chain,
DCA_PROVIDER_REMOVE, NULL);
spin_lock_irqsave(&dca_lock, flags);
list_del(&dca->node);
pci_rc = dca_pci_rc_from_dev(dev);
domain = dca_find_domain(pci_rc);
if (list_empty(&domain->dca_providers))
dca_free_domain(domain);
spin_unlock_irqrestore(&dca_lock, flags);
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)
{
pr_info("dca service started, version %s\n", DCA_VERSION);
return dca_sysfs_init();
}
static void __exit dca_exit(void)
{
dca_sysfs_exit();
}
arch_initcall(dca_init);
module_exit(dca_exit);