// 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(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()
*/
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);
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