Commit ff45f9dd authored Oct 29, 2015 by Ben Shelton Committed by Bjorn Helgaas Oct 29, 2015

PCI: Enable SR-IOV ARI Capable Hierarchy before reading TotalVFs



For some SR-IOV devices, the number of available virtual functions, i.e.,
TotalVFs, increases after setting the ARI Capable Hierarchy bit in the
SR-IOV Control register.  This violates the SR-IOV spec, r1.1, sec 3.3.6,
which says TotalVFs is HwInit, but we don't need TotalVFs before setting
the ARI Capable bit anyway.

Set the ARI Capable Hierarchy bit (if ARI is enabled in the upstream
bridge) before reading TotalVFs.

[bhelgaas: changelog]
Signed-off-by: Ben Shelton <benjamin.h.shelton@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

parent 70675e0b

drivers/pci/iov.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -399,10 +399,6 @@ static int sriov_init(struct pci_dev *dev, int pos)
		ssleep(1);
		}

		pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
		if (!total)
		return 0;

		ctrl = 0;
		list_for_each_entry(pdev, &dev->bus->devices, bus_list)
		if (pdev->is_physfn)
		@@ -420,6 +416,10 @@ found:
		if (!offset \|\| (total > 1 && !stride))
		return -EIO;

		pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
		if (!total)
		return 0;

		pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
		i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
		pgsz &= ~((1 << i) - 1);

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