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| author | Bjorn Helgaas <bhelgaas@google.com> | 2016-11-28 16:43:06 -0600 |
|---|---|---|
| committer | Bjorn Helgaas <bhelgaas@google.com> | 2016-11-29 18:05:09 -0600 |
| commit | 546ba9f8f22f71b0202b6ba8967be5cc6dae4e21 (patch) | |
| tree | 34c3b82c568c81e50a723aed5d2ec05684422bcb /drivers/pci/iov.c | |
| parent | 6ffa2489c51da77564a0881a73765ea2169f955d (diff) | |
| download | linux-546ba9f8f22f71b0202b6ba8967be5cc6dae4e21.tar.gz | |
PCI: Don't update VF BARs while VF memory space is enabled
If we update a VF BAR while it's enabled, there are two potential problems:
1) Any driver that's using the VF has a cached BAR value that is stale
after the update, and
2) We can't update 64-bit BARs atomically, so the intermediate state
(new lower dword with old upper dword) may conflict with another
device, and an access by a driver unrelated to the VF may cause a bus
error.
Warn about attempts to update VF BARs while they are enabled. This is a
programming error, so use dev_WARN() to get a backtrace.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com>Diffstat (limited to 'drivers/pci/iov.c')
| -rw-r--r-- | drivers/pci/iov.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c index aa499543473f..2480b3879182 100644 --- a/drivers/pci/iov.c +++ b/drivers/pci/iov.c @@ -584,6 +584,7 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno) struct resource *res = dev->resource + resno; int vf_bar = resno - PCI_IOV_RESOURCES; struct pci_bus_region region; + u16 cmd; u32 new; int reg; @@ -595,6 +596,13 @@ void pci_iov_update_resource(struct pci_dev *dev, int resno) if (!iov) return; + pci_read_config_word(dev, iov->pos + PCI_SRIOV_CTRL, &cmd); + if ((cmd & PCI_SRIOV_CTRL_VFE) && (cmd & PCI_SRIOV_CTRL_MSE)) { + dev_WARN(&dev->dev, "can't update enabled VF BAR%d %pR\n", + vf_bar, res); + return; + } + /* * Ignore unimplemented BARs, unused resource slots for 64-bit * BARs, and non-movable resources, e.g., those described via |