| /* |
| * 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 <linux/slab.h> |
| |
| #define DCA_VERSION "1.12.1" |
| |
| MODULE_VERSION(DCA_VERSION); |
| MODULE_LICENSE("GPL"); |
| MODULE_AUTHOR("Intel Corporation"); |
| |
| static DEFINE_RAW_SPINLOCK(dca_lock); |
| |
| static LIST_HEAD(dca_domains); |
| |
| static BLOCKING_NOTIFIER_HEAD(dca_provider_chain); |
| |
| static int dca_providers_blocked; |
| |
| 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 int dca_provider_ioat_ver_3_0(struct device *dev) |
| { |
| struct pci_dev *pdev = to_pci_dev(dev); |
| |
| return ((pdev->vendor == PCI_VENDOR_ID_INTEL) && |
| ((pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG0) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG1) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG2) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG3) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG4) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG5) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG6) || |
| (pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG7))); |
| } |
| |
| static void unregister_dca_providers(void) |
| { |
| struct dca_provider *dca, *_dca; |
| struct list_head unregistered_providers; |
| struct dca_domain *domain; |
| unsigned long flags; |
| |
| blocking_notifier_call_chain(&dca_provider_chain, |
| DCA_PROVIDER_REMOVE, NULL); |
| |
| INIT_LIST_HEAD(&unregistered_providers); |
| |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| |
| if (list_empty(&dca_domains)) { |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| return; |
| } |
| |
| /* at this point only one domain in the list is expected */ |
| domain = list_first_entry(&dca_domains, struct dca_domain, node); |
| |
| list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node) |
| list_move(&dca->node, &unregistered_providers); |
| |
| dca_free_domain(domain); |
| |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| |
| list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) { |
| dca_sysfs_remove_provider(dca); |
| list_del(&dca->node); |
| } |
| } |
| |
| 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) { |
| if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains)) |
| dca_providers_blocked = 1; |
| } |
| |
| 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; |
| |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| |
| /* check if the requester has not been added already */ |
| dca = dca_find_provider_by_dev(dev); |
| if (dca) { |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| return -EEXIST; |
| } |
| |
| pci_rc = dca_pci_rc_from_dev(dev); |
| domain = dca_find_domain(pci_rc); |
| if (!domain) { |
| raw_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; |
| } |
| |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| |
| if (slot < 0) |
| return slot; |
| |
| err = dca_sysfs_add_req(dca, dev, slot); |
| if (err) { |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| if (dca == dca_find_provider_by_dev(dev)) |
| dca->ops->remove_requester(dca, dev); |
| raw_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; |
| |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| dca = dca_find_provider_by_dev(dev); |
| if (!dca) { |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| return -ENODEV; |
| } |
| slot = dca->ops->remove_requester(dca, dev); |
| raw_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; |
| |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| |
| dca = dca_find_provider_by_dev(dev); |
| if (!dca) { |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| return -ENODEV; |
| } |
| tag = dca->ops->get_tag(dca, dev, cpu); |
| |
| raw_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); |
| |
| /** |
| * 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, *newdomain = NULL; |
| |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| if (dca_providers_blocked) { |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| return -ENODEV; |
| } |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| |
| err = dca_sysfs_add_provider(dca, dev); |
| if (err) |
| return err; |
| |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| domain = dca_get_domain(dev); |
| if (!domain) { |
| struct pci_bus *rc; |
| |
| if (dca_providers_blocked) { |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| dca_sysfs_remove_provider(dca); |
| unregister_dca_providers(); |
| return -ENODEV; |
| } |
| |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| rc = dca_pci_rc_from_dev(dev); |
| newdomain = dca_allocate_domain(rc); |
| if (!newdomain) |
| return -ENODEV; |
| raw_spin_lock_irqsave(&dca_lock, flags); |
| /* Recheck, we might have raced after dropping the lock */ |
| domain = dca_get_domain(dev); |
| if (!domain) { |
| domain = newdomain; |
| newdomain = NULL; |
| list_add(&domain->node, &dca_domains); |
| } |
| } |
| list_add(&dca->node, &domain->dca_providers); |
| raw_spin_unlock_irqrestore(&dca_lock, flags); |
| |
| blocking_notifier_call_chain(&dca_provider_chain, |
| DCA_PROVIDER_ADD, NULL); |
| kfree(newdomain); |
| 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); |
| |
| raw_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); |
| |
| raw_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); |
| |