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Commit 4e8cec26 authored by Sosnowski, Maciej's avatar Sosnowski, Maciej Committed by David S. Miller
Browse files

dca: disable dca on IOAT ver.3.0 multiple-IOH platforms 



Direct Cache Access is not supported on IOAT ver.3.0 multiple-IOH platforms.
This patch blocks registering of dca providers when multiple IOH detected with IOAT ver.3.0.

Signed-off-by: default avatarMaciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f0f9deae

drivers/dca/dca-core.c

+79 −6
Original line number Diff line number Diff line
@@ -39,6 +39,10 @@ static DEFINE_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);
@@ -70,6 +74,60 @@ static void dca_free_domain(struct dca_domain *domain) 
	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);



	spin_lock_irqsave(&dca_lock, flags);



	if (list_empty(&dca_domains)) {

		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);

	if (!domain)

		return;



	list_for_each_entry_safe(dca, _dca, &domain->dca_providers, node) {

		list_del(&dca->node);

		list_add(&dca->node, &unregistered_providers);

	}



	dca_free_domain(domain);



	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;
@@ -90,10 +148,14 @@ static struct dca_domain *dca_get_domain(struct device *dev) 
	domain = dca_find_domain(rc);



	if (!domain) {

		if (dca_provider_ioat_ver_3_0(dev) && !list_empty(&dca_domains)) {

			dca_providers_blocked = 1;

		} else {

			domain = dca_allocate_domain(rc);

			if (domain)

				list_add(&domain->node, &dca_domains);

		}

	}



	return domain;

}
@@ -293,8 +355,6 @@ void free_dca_provider(struct dca_provider *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()
@@ -306,6 +366,13 @@ int register_dca_provider(struct dca_provider *dca, struct device *dev) 
	unsigned long flags;

	struct dca_domain *domain;



	spin_lock_irqsave(&dca_lock, flags);

	if (dca_providers_blocked) {

		spin_unlock_irqrestore(&dca_lock, flags);

		return -ENODEV;

	}

	spin_unlock_irqrestore(&dca_lock, flags);



	err = dca_sysfs_add_provider(dca, dev);

	if (err)

		return err;
@@ -313,7 +380,13 @@ int register_dca_provider(struct dca_provider *dca, struct device *dev) 
	spin_lock_irqsave(&dca_lock, flags);

	domain = dca_get_domain(dev);

	if (!domain) {

		if (dca_providers_blocked) {

			spin_unlock_irqrestore(&dca_lock, flags);

			dca_sysfs_remove_provider(dca);

			unregister_dca_providers();

		} else {

			spin_unlock_irqrestore(&dca_lock, flags);

		}

		return -ENODEV;

	}

	list_add(&dca->node, &domain->dca_providers);