// SPDX-License-Identifier: GPL-2.0-or-later/* * Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved. */ /* * 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>#include <linux/module.h> #define DCA_VERSION "1.12.1" MODULE_VERSION(DCA_VERSION);MODULE_DESCRIPTION("Intel Direct Cache Access (DCA) service module");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_obj(*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() */static 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){	return dca_common_get_tag(NULL, 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(const 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); 	if (list_empty(&dca_domains)) {		raw_spin_unlock_irqrestore(&dca_lock, flags);		return;	} 	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);