[RFC 2/4] pci/sriov: add vf_bitmap to mark the vf id allocation

["Longpeng(Mike)" <longpeng2@huawei.com>]

From: Longpeng <longpeng2@huawei.com>

Add a bitmap to mark the vf id allocation, the can be use to
avoid the repeated allocations.

Signed-off-by: Longpeng <longpeng2@huawei.com>
---
 drivers/pci/iov.c | 13 +++++++++++++
 drivers/pci/pci.h |  1 +
 2 files changed, 14 insertions(+)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 3b441cd92960..886489aae0de 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -341,6 +341,8 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
 
 	pci_bus_add_device(virtfn);
 
+	__set_bit(id, iov->vf_bitmap);
+
 	return 0;
 
 failed1:
@@ -357,6 +359,7 @@ void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 {
 	char buf[VIRTFN_ID_LEN];
 	struct pci_dev *virtfn;
+	struct pci_sriov *iov;
 
 	virtfn = pci_get_domain_bus_and_slot(pci_domain_nr(dev->bus),
 					     pci_iov_virtfn_bus(dev, id),
@@ -364,6 +367,9 @@ void pci_iov_remove_virtfn(struct pci_dev *dev, int id)
 	if (!virtfn)
 		return;
 
+	iov = pci_physfn(dev)->sriov;
+	__clear_bit(id, iov->vf_bitmap);
+
 	sprintf(buf, "virtfn%u", id);
 	sysfs_remove_link(&dev->dev.kobj, buf);
 	/*
@@ -791,6 +797,11 @@ static int sriov_init(struct pci_dev *dev, int pos)
 	if (!iov)
 		return -ENOMEM;
 
+	rc = -ENOMEM;
+	iov->vf_bitmap = bitmap_zalloc(total, GFP_KERNEL);
+	if (!iov->vf_bitmap)
+		goto free_iov;
+
 	nres = 0;
 	for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
 		res = &dev->resource[i + PCI_IOV_RESOURCES];
@@ -853,6 +864,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 		res->flags = 0;
 	}
 
+free_iov:
 	kfree(iov);
 	return rc;
 }
@@ -864,6 +876,7 @@ static void sriov_release(struct pci_dev *dev)
 	if (dev != dev->sriov->dev)
 		pci_dev_put(dev->sriov->dev);
 
+	bitmap_free(dev->sriov->vf_bitmap);
 	kfree(dev->sriov);
 	dev->sriov = NULL;
 }
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b1ebb7ab8805..a76d4ff83886 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -301,6 +301,7 @@ struct pci_sriov {
 	u16		subsystem_device; /* VF subsystem device */
 	resource_size_t	barsz[PCI_SRIOV_NUM_BARS];	/* VF BAR size */
 	bool		drivers_autoprobe; /* Auto probing of VFs by driver */
+	unsigned long   *vf_bitmap;     /* Allocated VFs */
 };
 
 /**
-- 
2.23.0