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457 lines
10 KiB
457 lines
10 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
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/* |
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* Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved. |
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*/ |
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/* |
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* This driver supports an interface for DCA clients and providers to meet. |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/notifier.h> |
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#include <linux/device.h> |
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#include <linux/dca.h> |
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#include <linux/slab.h> |
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#include <linux/module.h> |
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#define DCA_VERSION "1.12.1" |
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MODULE_VERSION(DCA_VERSION); |
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MODULE_LICENSE("GPL"); |
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MODULE_AUTHOR("Intel Corporation"); |
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static DEFINE_RAW_SPINLOCK(dca_lock); |
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static LIST_HEAD(dca_domains); |
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static BLOCKING_NOTIFIER_HEAD(dca_provider_chain); |
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static int dca_providers_blocked; |
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static struct pci_bus *dca_pci_rc_from_dev(struct device *dev) |
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{ |
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struct pci_dev *pdev = to_pci_dev(dev); |
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struct pci_bus *bus = pdev->bus; |
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while (bus->parent) |
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bus = bus->parent; |
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return bus; |
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} |
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static struct dca_domain *dca_allocate_domain(struct pci_bus *rc) |
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{ |
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struct dca_domain *domain; |
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domain = kzalloc(sizeof(*domain), GFP_NOWAIT); |
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if (!domain) |
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return NULL; |
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INIT_LIST_HEAD(&domain->dca_providers); |
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domain->pci_rc = rc; |
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return domain; |
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} |
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static void dca_free_domain(struct dca_domain *domain) |
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{ |
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list_del(&domain->node); |
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kfree(domain); |
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} |
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static int dca_provider_ioat_ver_3_0(struct device *dev) |
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{ |
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struct pci_dev *pdev = to_pci_dev(dev); |
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return ((pdev->vendor == PCI_VENDOR_ID_INTEL) && |
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((pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG0) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG1) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG2) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG3) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG4) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG5) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG6) || |
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(pdev->device == PCI_DEVICE_ID_INTEL_IOAT_TBG7))); |
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} |
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static void unregister_dca_providers(void) |
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{ |
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struct dca_provider *dca, *_dca; |
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struct list_head unregistered_providers; |
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struct dca_domain *domain; |
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unsigned long flags; |
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blocking_notifier_call_chain(&dca_provider_chain, |
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DCA_PROVIDER_REMOVE, NULL); |
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INIT_LIST_HEAD(&unregistered_providers); |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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if (list_empty(&dca_domains)) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return; |
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} |
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/* at this point only one domain in the list is expected */ |
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domain = list_first_entry(&dca_domains, struct dca_domain, node); |
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list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node) |
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list_move(&dca->node, &unregistered_providers); |
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dca_free_domain(domain); |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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list_for_each_entry_safe(dca, _dca, &unregistered_providers, node) { |
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dca_sysfs_remove_provider(dca); |
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list_del(&dca->node); |
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} |
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} |
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static struct dca_domain *dca_find_domain(struct pci_bus *rc) |
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{ |
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struct dca_domain *domain; |
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list_for_each_entry(domain, &dca_domains, node) |
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if (domain->pci_rc == rc) |
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return domain; |
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return NULL; |
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} |
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static struct dca_domain *dca_get_domain(struct device *dev) |
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{ |
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struct pci_bus *rc; |
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struct dca_domain *domain; |
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rc = dca_pci_rc_from_dev(dev); |
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domain = dca_find_domain(rc); |
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if (!domain) { |
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if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains)) |
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dca_providers_blocked = 1; |
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} |
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return domain; |
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} |
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static struct dca_provider *dca_find_provider_by_dev(struct device *dev) |
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{ |
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struct dca_provider *dca; |
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struct pci_bus *rc; |
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struct dca_domain *domain; |
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if (dev) { |
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rc = dca_pci_rc_from_dev(dev); |
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domain = dca_find_domain(rc); |
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if (!domain) |
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return NULL; |
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} else { |
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if (!list_empty(&dca_domains)) |
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domain = list_first_entry(&dca_domains, |
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struct dca_domain, |
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node); |
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else |
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return NULL; |
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} |
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list_for_each_entry(dca, &domain->dca_providers, node) |
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if ((!dev) || (dca->ops->dev_managed(dca, dev))) |
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return dca; |
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return NULL; |
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} |
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/** |
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* dca_add_requester - add a dca client to the list |
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* @dev - the device that wants dca service |
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*/ |
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int dca_add_requester(struct device *dev) |
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{ |
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struct dca_provider *dca; |
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int err, slot = -ENODEV; |
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unsigned long flags; |
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struct pci_bus *pci_rc; |
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struct dca_domain *domain; |
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if (!dev) |
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return -EFAULT; |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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/* check if the requester has not been added already */ |
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dca = dca_find_provider_by_dev(dev); |
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if (dca) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return -EEXIST; |
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} |
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pci_rc = dca_pci_rc_from_dev(dev); |
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domain = dca_find_domain(pci_rc); |
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if (!domain) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return -ENODEV; |
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} |
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list_for_each_entry(dca, &domain->dca_providers, node) { |
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slot = dca->ops->add_requester(dca, dev); |
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if (slot >= 0) |
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break; |
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} |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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if (slot < 0) |
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return slot; |
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err = dca_sysfs_add_req(dca, dev, slot); |
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if (err) { |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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if (dca == dca_find_provider_by_dev(dev)) |
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dca->ops->remove_requester(dca, dev); |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return err; |
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} |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(dca_add_requester); |
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/** |
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* dca_remove_requester - remove a dca client from the list |
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* @dev - the device that wants dca service |
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*/ |
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int dca_remove_requester(struct device *dev) |
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{ |
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struct dca_provider *dca; |
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int slot; |
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unsigned long flags; |
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if (!dev) |
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return -EFAULT; |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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dca = dca_find_provider_by_dev(dev); |
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if (!dca) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return -ENODEV; |
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} |
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slot = dca->ops->remove_requester(dca, dev); |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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if (slot < 0) |
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return slot; |
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dca_sysfs_remove_req(dca, slot); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(dca_remove_requester); |
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/** |
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* dca_common_get_tag - return the dca tag (serves both new and old api) |
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* @dev - the device that wants dca service |
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* @cpu - the cpuid as returned by get_cpu() |
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*/ |
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static u8 dca_common_get_tag(struct device *dev, int cpu) |
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{ |
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struct dca_provider *dca; |
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u8 tag; |
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unsigned long flags; |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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dca = dca_find_provider_by_dev(dev); |
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if (!dca) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return -ENODEV; |
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} |
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tag = dca->ops->get_tag(dca, dev, cpu); |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return tag; |
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} |
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/** |
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* dca3_get_tag - return the dca tag to the requester device |
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* for the given cpu (new api) |
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* @dev - the device that wants dca service |
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* @cpu - the cpuid as returned by get_cpu() |
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*/ |
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u8 dca3_get_tag(struct device *dev, int cpu) |
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{ |
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if (!dev) |
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return -EFAULT; |
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return dca_common_get_tag(dev, cpu); |
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} |
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EXPORT_SYMBOL_GPL(dca3_get_tag); |
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/** |
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* dca_get_tag - return the dca tag for the given cpu (old api) |
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* @cpu - the cpuid as returned by get_cpu() |
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*/ |
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u8 dca_get_tag(int cpu) |
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{ |
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struct device *dev = NULL; |
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return dca_common_get_tag(dev, cpu); |
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} |
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EXPORT_SYMBOL_GPL(dca_get_tag); |
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/** |
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* alloc_dca_provider - get data struct for describing a dca provider |
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* @ops - pointer to struct of dca operation function pointers |
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* @priv_size - size of extra mem to be added for provider's needs |
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*/ |
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struct dca_provider *alloc_dca_provider(const struct dca_ops *ops, |
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int priv_size) |
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{ |
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struct dca_provider *dca; |
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int alloc_size; |
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alloc_size = (sizeof(*dca) + priv_size); |
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dca = kzalloc(alloc_size, GFP_KERNEL); |
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if (!dca) |
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return NULL; |
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dca->ops = ops; |
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return dca; |
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} |
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EXPORT_SYMBOL_GPL(alloc_dca_provider); |
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/** |
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* free_dca_provider - release the dca provider data struct |
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* @ops - pointer to struct of dca operation function pointers |
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* @priv_size - size of extra mem to be added for provider's needs |
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*/ |
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void free_dca_provider(struct dca_provider *dca) |
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{ |
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kfree(dca); |
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} |
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EXPORT_SYMBOL_GPL(free_dca_provider); |
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/** |
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* register_dca_provider - register a dca provider |
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* @dca - struct created by alloc_dca_provider() |
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* @dev - device providing dca services |
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*/ |
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int register_dca_provider(struct dca_provider *dca, struct device *dev) |
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{ |
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int err; |
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unsigned long flags; |
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struct dca_domain *domain, *newdomain = NULL; |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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if (dca_providers_blocked) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return -ENODEV; |
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} |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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err = dca_sysfs_add_provider(dca, dev); |
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if (err) |
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return err; |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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domain = dca_get_domain(dev); |
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if (!domain) { |
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struct pci_bus *rc; |
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if (dca_providers_blocked) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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dca_sysfs_remove_provider(dca); |
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unregister_dca_providers(); |
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return -ENODEV; |
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} |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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rc = dca_pci_rc_from_dev(dev); |
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newdomain = dca_allocate_domain(rc); |
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if (!newdomain) |
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return -ENODEV; |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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/* Recheck, we might have raced after dropping the lock */ |
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domain = dca_get_domain(dev); |
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if (!domain) { |
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domain = newdomain; |
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newdomain = NULL; |
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list_add(&domain->node, &dca_domains); |
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} |
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} |
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list_add(&dca->node, &domain->dca_providers); |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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blocking_notifier_call_chain(&dca_provider_chain, |
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DCA_PROVIDER_ADD, NULL); |
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kfree(newdomain); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(register_dca_provider); |
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/** |
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* unregister_dca_provider - remove a dca provider |
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* @dca - struct created by alloc_dca_provider() |
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*/ |
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void unregister_dca_provider(struct dca_provider *dca, struct device *dev) |
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{ |
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unsigned long flags; |
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struct pci_bus *pci_rc; |
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struct dca_domain *domain; |
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blocking_notifier_call_chain(&dca_provider_chain, |
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DCA_PROVIDER_REMOVE, NULL); |
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raw_spin_lock_irqsave(&dca_lock, flags); |
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if (list_empty(&dca_domains)) { |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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return; |
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} |
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list_del(&dca->node); |
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pci_rc = dca_pci_rc_from_dev(dev); |
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domain = dca_find_domain(pci_rc); |
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if (list_empty(&domain->dca_providers)) |
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dca_free_domain(domain); |
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raw_spin_unlock_irqrestore(&dca_lock, flags); |
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dca_sysfs_remove_provider(dca); |
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} |
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EXPORT_SYMBOL_GPL(unregister_dca_provider); |
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/** |
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* dca_register_notify - register a client's notifier callback |
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*/ |
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void dca_register_notify(struct notifier_block *nb) |
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{ |
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blocking_notifier_chain_register(&dca_provider_chain, nb); |
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} |
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EXPORT_SYMBOL_GPL(dca_register_notify); |
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/** |
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* dca_unregister_notify - remove a client's notifier callback |
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*/ |
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void dca_unregister_notify(struct notifier_block *nb) |
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{ |
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blocking_notifier_chain_unregister(&dca_provider_chain, nb); |
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} |
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EXPORT_SYMBOL_GPL(dca_unregister_notify); |
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static int __init dca_init(void) |
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{ |
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pr_info("dca service started, version %s\n", DCA_VERSION); |
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return dca_sysfs_init(); |
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} |
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static void __exit dca_exit(void) |
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{ |
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dca_sysfs_exit(); |
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} |
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arch_initcall(dca_init); |
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module_exit(dca_exit); |
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