forked from mirrors/linux
		
	PCI: add SR-IOV API for Physical Function driver
Add or remove the Virtual Function when the SR-IOV is enabled or disabled by the device driver. This can happen anytime rather than only at the device probe stage. Reviewed-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Yu Zhao <yu.zhao@intel.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
		
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						dd7cc44d0b
					
				
					 3 changed files with 334 additions and 1 deletions
				
			
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			@ -13,6 +13,7 @@
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#include <linux/delay.h>
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#include "pci.h"
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#define VIRTFN_ID_LEN	16
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static inline u8 virtfn_bus(struct pci_dev *dev, int id)
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{
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			@ -26,6 +27,284 @@ static inline u8 virtfn_devfn(struct pci_dev *dev, int id)
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		dev->sriov->stride * id) & 0xff;
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}
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static struct pci_bus *virtfn_add_bus(struct pci_bus *bus, int busnr)
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{
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	int rc;
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	struct pci_bus *child;
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	if (bus->number == busnr)
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		return bus;
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	child = pci_find_bus(pci_domain_nr(bus), busnr);
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	if (child)
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		return child;
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	child = pci_add_new_bus(bus, NULL, busnr);
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	if (!child)
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		return NULL;
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	child->subordinate = busnr;
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	child->dev.parent = bus->bridge;
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	rc = pci_bus_add_child(child);
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	if (rc) {
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		pci_remove_bus(child);
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		return NULL;
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	}
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	return child;
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}
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static void virtfn_remove_bus(struct pci_bus *bus, int busnr)
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{
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	struct pci_bus *child;
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	if (bus->number == busnr)
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		return;
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	child = pci_find_bus(pci_domain_nr(bus), busnr);
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	BUG_ON(!child);
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	if (list_empty(&child->devices))
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		pci_remove_bus(child);
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}
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static int virtfn_add(struct pci_dev *dev, int id, int reset)
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{
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	int i;
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	int rc;
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	u64 size;
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	char buf[VIRTFN_ID_LEN];
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	struct pci_dev *virtfn;
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	struct resource *res;
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	struct pci_sriov *iov = dev->sriov;
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	virtfn = alloc_pci_dev();
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	if (!virtfn)
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		return -ENOMEM;
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	mutex_lock(&iov->dev->sriov->lock);
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	virtfn->bus = virtfn_add_bus(dev->bus, virtfn_bus(dev, id));
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	if (!virtfn->bus) {
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		kfree(virtfn);
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		mutex_unlock(&iov->dev->sriov->lock);
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		return -ENOMEM;
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	}
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	virtfn->devfn = virtfn_devfn(dev, id);
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	virtfn->vendor = dev->vendor;
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	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_DID, &virtfn->device);
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	pci_setup_device(virtfn);
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	virtfn->dev.parent = dev->dev.parent;
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	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
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		res = dev->resource + PCI_IOV_RESOURCES + i;
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		if (!res->parent)
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			continue;
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		virtfn->resource[i].name = pci_name(virtfn);
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		virtfn->resource[i].flags = res->flags;
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		size = resource_size(res);
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		do_div(size, iov->total);
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		virtfn->resource[i].start = res->start + size * id;
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		virtfn->resource[i].end = virtfn->resource[i].start + size - 1;
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		rc = request_resource(res, &virtfn->resource[i]);
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		BUG_ON(rc);
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	}
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	if (reset)
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		pci_execute_reset_function(virtfn);
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	pci_device_add(virtfn, virtfn->bus);
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	mutex_unlock(&iov->dev->sriov->lock);
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	virtfn->physfn = pci_dev_get(dev);
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	virtfn->is_virtfn = 1;
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	rc = pci_bus_add_device(virtfn);
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	if (rc)
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		goto failed1;
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	sprintf(buf, "virtfn%u", id);
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	rc = sysfs_create_link(&dev->dev.kobj, &virtfn->dev.kobj, buf);
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	if (rc)
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		goto failed1;
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	rc = sysfs_create_link(&virtfn->dev.kobj, &dev->dev.kobj, "physfn");
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	if (rc)
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		goto failed2;
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	kobject_uevent(&virtfn->dev.kobj, KOBJ_CHANGE);
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	return 0;
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failed2:
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	sysfs_remove_link(&dev->dev.kobj, buf);
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failed1:
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	pci_dev_put(dev);
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	mutex_lock(&iov->dev->sriov->lock);
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	pci_remove_bus_device(virtfn);
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	virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
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	mutex_unlock(&iov->dev->sriov->lock);
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	return rc;
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}
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static void virtfn_remove(struct pci_dev *dev, int id, int reset)
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{
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	char buf[VIRTFN_ID_LEN];
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	struct pci_bus *bus;
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	struct pci_dev *virtfn;
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	struct pci_sriov *iov = dev->sriov;
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	bus = pci_find_bus(pci_domain_nr(dev->bus), virtfn_bus(dev, id));
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	if (!bus)
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		return;
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	virtfn = pci_get_slot(bus, virtfn_devfn(dev, id));
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	if (!virtfn)
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		return;
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	pci_dev_put(virtfn);
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	if (reset) {
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		device_release_driver(&virtfn->dev);
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		pci_execute_reset_function(virtfn);
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	}
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	sprintf(buf, "virtfn%u", id);
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	sysfs_remove_link(&dev->dev.kobj, buf);
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	sysfs_remove_link(&virtfn->dev.kobj, "physfn");
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	mutex_lock(&iov->dev->sriov->lock);
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	pci_remove_bus_device(virtfn);
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	virtfn_remove_bus(dev->bus, virtfn_bus(dev, id));
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	mutex_unlock(&iov->dev->sriov->lock);
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	pci_dev_put(dev);
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}
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static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
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{
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	int rc;
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	int i, j;
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	int nres;
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	u16 offset, stride, initial;
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	struct resource *res;
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	struct pci_dev *pdev;
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	struct pci_sriov *iov = dev->sriov;
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	if (!nr_virtfn)
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		return 0;
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	if (iov->nr_virtfn)
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		return -EINVAL;
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	pci_read_config_word(dev, iov->pos + PCI_SRIOV_INITIAL_VF, &initial);
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	if (initial > iov->total ||
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	    (!(iov->cap & PCI_SRIOV_CAP_VFM) && (initial != iov->total)))
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		return -EIO;
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	if (nr_virtfn < 0 || nr_virtfn > iov->total ||
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	    (!(iov->cap & PCI_SRIOV_CAP_VFM) && (nr_virtfn > initial)))
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		return -EINVAL;
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	pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, nr_virtfn);
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	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_OFFSET, &offset);
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	pci_read_config_word(dev, iov->pos + PCI_SRIOV_VF_STRIDE, &stride);
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	if (!offset || (nr_virtfn > 1 && !stride))
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		return -EIO;
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	nres = 0;
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	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
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		res = dev->resource + PCI_IOV_RESOURCES + i;
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		if (res->parent)
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			nres++;
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	}
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	if (nres != iov->nres) {
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		dev_err(&dev->dev, "not enough MMIO resources for SR-IOV\n");
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		return -ENOMEM;
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	}
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	iov->offset = offset;
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	iov->stride = stride;
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	if (virtfn_bus(dev, nr_virtfn - 1) > dev->bus->subordinate) {
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		dev_err(&dev->dev, "SR-IOV: bus number out of range\n");
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		return -ENOMEM;
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	}
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	if (iov->link != dev->devfn) {
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		pdev = pci_get_slot(dev->bus, iov->link);
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		if (!pdev)
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			return -ENODEV;
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		pci_dev_put(pdev);
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		if (!pdev->is_physfn)
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			return -ENODEV;
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		rc = sysfs_create_link(&dev->dev.kobj,
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					&pdev->dev.kobj, "dep_link");
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		if (rc)
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			return rc;
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	}
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	iov->ctrl |= PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE;
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	pci_block_user_cfg_access(dev);
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	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
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	msleep(100);
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	pci_unblock_user_cfg_access(dev);
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	iov->initial = initial;
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	if (nr_virtfn < initial)
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		initial = nr_virtfn;
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	for (i = 0; i < initial; i++) {
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		rc = virtfn_add(dev, i, 0);
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		if (rc)
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			goto failed;
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	}
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	kobject_uevent(&dev->dev.kobj, KOBJ_CHANGE);
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	iov->nr_virtfn = nr_virtfn;
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	return 0;
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failed:
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	for (j = 0; j < i; j++)
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		virtfn_remove(dev, j, 0);
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	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
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	pci_block_user_cfg_access(dev);
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	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
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	ssleep(1);
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	pci_unblock_user_cfg_access(dev);
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	if (iov->link != dev->devfn)
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		sysfs_remove_link(&dev->dev.kobj, "dep_link");
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	return rc;
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}
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static void sriov_disable(struct pci_dev *dev)
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{
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	int i;
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	struct pci_sriov *iov = dev->sriov;
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	if (!iov->nr_virtfn)
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		return;
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	for (i = 0; i < iov->nr_virtfn; i++)
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		virtfn_remove(dev, i, 0);
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	iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
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	pci_block_user_cfg_access(dev);
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	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
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	ssleep(1);
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	pci_unblock_user_cfg_access(dev);
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	if (iov->link != dev->devfn)
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		sysfs_remove_link(&dev->dev.kobj, "dep_link");
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	iov->nr_virtfn = 0;
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}
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static int sriov_init(struct pci_dev *dev, int pos)
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{
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	int i;
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			@ -132,6 +411,8 @@ static int sriov_init(struct pci_dev *dev, int pos)
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static void sriov_release(struct pci_dev *dev)
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{
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	BUG_ON(dev->sriov->nr_virtfn);
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	if (dev == dev->sriov->dev)
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		mutex_destroy(&dev->sriov->lock);
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	else
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			@ -155,6 +436,7 @@ static void sriov_restore_state(struct pci_dev *dev)
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		pci_update_resource(dev, i);
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	pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
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	pci_write_config_word(dev, iov->pos + PCI_SRIOV_NUM_VF, iov->nr_virtfn);
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	pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
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	if (iov->ctrl & PCI_SRIOV_CTRL_VFE)
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		msleep(100);
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			@ -245,3 +527,35 @@ int pci_iov_bus_range(struct pci_bus *bus)
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	return max ? max - bus->number : 0;
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}
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/**
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 * pci_enable_sriov - enable the SR-IOV capability
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 * @dev: the PCI device
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 *
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 * Returns 0 on success, or negative on failure.
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 */
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int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
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{
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	might_sleep();
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	if (!dev->is_physfn)
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		return -ENODEV;
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	return sriov_enable(dev, nr_virtfn);
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}
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EXPORT_SYMBOL_GPL(pci_enable_sriov);
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/**
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 * pci_disable_sriov - disable the SR-IOV capability
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 * @dev: the PCI device
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 */
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void pci_disable_sriov(struct pci_dev *dev)
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{
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	might_sleep();
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	if (!dev->is_physfn)
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		return;
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	sriov_disable(dev);
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}
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EXPORT_SYMBOL_GPL(pci_disable_sriov);
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			@ -209,6 +209,8 @@ struct pci_sriov {
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	u32 cap;		/* SR-IOV Capabilities */
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	u16 ctrl;		/* SR-IOV Control */
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	u16 total;		/* total VFs associated with the PF */
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	u16 initial;		/* initial VFs associated with the PF */
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	u16 nr_virtfn;		/* number of VFs available */
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	u16 offset;		/* first VF Routing ID offset */
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	u16 stride;		/* following VF stride */
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	u32 pgsz;		/* page size for BAR alignment */
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						 | 
				
			
			
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			@ -265,6 +265,7 @@ struct pci_dev {
 | 
			
		|||
	unsigned int	is_pcie:1;
 | 
			
		||||
	unsigned int	state_saved:1;
 | 
			
		||||
	unsigned int	is_physfn:1;
 | 
			
		||||
	unsigned int	is_virtfn:1;
 | 
			
		||||
	pci_dev_flags_t dev_flags;
 | 
			
		||||
	atomic_t	enable_cnt;	/* pci_enable_device has been called */
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -279,7 +280,10 @@ struct pci_dev {
 | 
			
		|||
#endif
 | 
			
		||||
	struct pci_vpd *vpd;
 | 
			
		||||
#ifdef CONFIG_PCI_IOV
 | 
			
		||||
	struct pci_sriov *sriov;	/* SR-IOV capability related */
 | 
			
		||||
	union {
 | 
			
		||||
		struct pci_sriov *sriov;	/* SR-IOV capability related */
 | 
			
		||||
		struct pci_dev *physfn;	/* the PF this VF is associated with */
 | 
			
		||||
	};
 | 
			
		||||
#endif
 | 
			
		||||
};
 | 
			
		||||
 | 
			
		||||
| 
						 | 
				
			
			@ -1212,5 +1216,18 @@ int pci_ext_cfg_avail(struct pci_dev *dev);
 | 
			
		|||
 | 
			
		||||
void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar);
 | 
			
		||||
 | 
			
		||||
#ifdef CONFIG_PCI_IOV
 | 
			
		||||
extern int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn);
 | 
			
		||||
extern void pci_disable_sriov(struct pci_dev *dev);
 | 
			
		||||
#else
 | 
			
		||||
static inline int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn)
 | 
			
		||||
{
 | 
			
		||||
	return -ENODEV;
 | 
			
		||||
}
 | 
			
		||||
static inline void pci_disable_sriov(struct pci_dev *dev)
 | 
			
		||||
{
 | 
			
		||||
}
 | 
			
		||||
#endif
 | 
			
		||||
 | 
			
		||||
#endif /* __KERNEL__ */
 | 
			
		||||
#endif /* LINUX_PCI_H */
 | 
			
		||||
| 
						 | 
				
			
			
 | 
			
		|||
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