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Commit d9c3d6ff authored by Keith Busch's avatar Keith Busch Committed by Bjorn Helgaas
Browse files

x86/PCI: Allow DMA ops specific to a PCI domain 



The Intel Volume Management Device (VMD) is a PCIe endpoint that acts as a
host bridge to another PCI domain.  When devices below the VMD perform DMA,
the VMD replaces their DMA source IDs with its own source ID.  Therefore,
those devices require special DMA ops.

Add interfaces to allow the VMD driver to set up dma_ops for the devices
below it.

[bhelgaas: remove "extern", add "static", changelog]
Signed-off-by: default avatarKeith Busch <keith.busch@intel.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
parent 64bce3e8

arch/x86/include/asm/device.h

+10 −0
Original line number Diff line number Diff line
@@ -10,6 +10,16 @@ struct dev_archdata { 
#endif

};



#if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)

struct dma_domain {

	struct list_head node;

	struct dma_map_ops *dma_ops;

	int domain_nr;

};

void add_dma_domain(struct dma_domain *domain);

void del_dma_domain(struct dma_domain *domain);

#endif



struct pdev_archdata {

};

arch/x86/pci/common.c

+38 −0
Original line number Diff line number Diff line
@@ -641,6 +641,43 @@ unsigned int pcibios_assign_all_busses(void) 
	return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;

}



#if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)

static LIST_HEAD(dma_domain_list);

static DEFINE_SPINLOCK(dma_domain_list_lock);



void add_dma_domain(struct dma_domain *domain)

{

	spin_lock(&dma_domain_list_lock);

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

	spin_unlock(&dma_domain_list_lock);

}

EXPORT_SYMBOL_GPL(add_dma_domain);



void del_dma_domain(struct dma_domain *domain)

{

	spin_lock(&dma_domain_list_lock);

	list_del(&domain->node);

	spin_unlock(&dma_domain_list_lock);

}

EXPORT_SYMBOL_GPL(del_dma_domain);



static void set_dma_domain_ops(struct pci_dev *pdev)

{

	struct dma_domain *domain;



	spin_lock(&dma_domain_list_lock);

	list_for_each_entry(domain, &dma_domain_list, node) {

		if (pci_domain_nr(pdev->bus) == domain->domain_nr) {

			pdev->dev.archdata.dma_ops = domain->dma_ops;

			break;

		}

	}

	spin_unlock(&dma_domain_list_lock);

}

#else

static void set_dma_domain_ops(struct pci_dev *pdev) {}

#endif



int pcibios_add_device(struct pci_dev *dev)

{

	struct setup_data *data;
@@ -670,6 +707,7 @@ int pcibios_add_device(struct pci_dev *dev) 
		pa_data = data->next;

		iounmap(data);

	}

	set_dma_domain_ops(dev);

	return 0;

}