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Subject[PATCH 3/5] iov: Fix sriov_enable exception handling path
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>From what I can tell there were several errors in the sriov_enable
exception handling path. Below is a brief list of what I believe I am
fixing:

1. If pcibios_enable_sriov failed, we returned without disabling SR-IOV on
the device.
2. If virtfn_add failed we didn't call pcibios_disable_sriov to undo
pcibios_enable_sriov.
3. We were resetting numvfs to 0 before a second had passed for the VFs to
quiesce.
4. Minor coding style issues for white space and for assignment in
conditional check.

Beyond addressing these 4 issues there were also 2 other minor issues in
that retval was a redundant variable with rc, and j wasn't actually needed
as we could simply reverse the loop we were running when setting up i. As
such I have updated the code to address those two items.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
drivers/pci/iov.c | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 238950412de0..cecc242c1af0 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -231,13 +231,18 @@ static void virtfn_remove(struct pci_dev *dev, int id, int reset)

int __weak pcibios_sriov_enable(struct pci_dev *pdev, u16 num_vfs)
{
- return 0;
+ return 0;
+}
+
+int __weak pcibios_sriov_disable(struct pci_dev *pdev)
+{
+ return 0;
}

static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
{
int rc;
- int i, j;
+ int i;
int nres;
u16 offset, stride, initial;
struct resource *res;
@@ -245,7 +250,6 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
struct pci_sriov *iov = dev->sriov;
int bars = 0;
int bus;
- int retval;

if (!nr_virtfn)
return 0;
@@ -322,10 +326,11 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
if (nr_virtfn < initial)
initial = nr_virtfn;

- if ((retval = pcibios_sriov_enable(dev, initial))) {
+ rc = pcibios_sriov_enable(dev, initial);
+ if (rc) {
dev_err(&dev->dev, "failure %d from pcibios_sriov_enable()\n",
- retval);
- return retval;
+ rc);
+ goto err_pcibios;
}

for (i = 0; i < initial; i++) {
@@ -340,25 +345,23 @@ static int sriov_enable(struct pci_dev *dev, int nr_virtfn)
return 0;

failed:
- for (j = 0; j < i; j++)
- virtfn_remove(dev, j, 0);
+ while (i--)
+ virtfn_remove(dev, i, 0);

+ pcibios_sriov_disable(dev);
+err_pcibios:
iov->ctrl &= ~(PCI_SRIOV_CTRL_VFE | PCI_SRIOV_CTRL_MSE);
pci_cfg_access_lock(dev);
pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, iov->ctrl);
- pci_iov_set_numvfs(dev, 0);
ssleep(1);
pci_cfg_access_unlock(dev);

if (iov->link != dev->devfn)
sysfs_remove_link(&dev->dev.kobj, "dep_link");

- return rc;
-}
+ pci_iov_set_numvfs(dev, 0);

-int __weak pcibios_sriov_disable(struct pci_dev *pdev)
-{
- return 0;
+ return rc;
}

static void sriov_disable(struct pci_dev *dev)


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