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PCI: Remove spurious error for sriov_numvfs store and simplify flow

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If we request "num_vfs" and the driver's sriov_configure() method enables
exactly that number ("num_vfs_enabled"), we complain "Invalid value for
number of VFs to enable" and return an error.  We should silently return
success instead.

Also, use kstrtou16() since numVFs is defined to be a 16-bit field and
rework to simplify control flow.

Reported-by: Greg Rose <gregory.v.rose@intel.com>
Reference: http://lkml.kernel.org/r/20121214101911.00002f59@unknown
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Donald Dutile <ddutile@redhat.com>
This commit is contained in:
Bjorn Helgaas 2012-12-26 10:39:22 -07:00
parent a49f0d1ea3
commit faa48a507f
1 changed files with 35 additions and 52 deletions
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87
drivers/pci/pci-sysfs.c
View file

@ -422,77 +422,60 @@ static ssize_t sriov_numvfs_show(struct device *dev,
}
/*
* num_vfs > 0; number of vfs to enable
* num_vfs = 0; disable all vfs
* num_vfs > 0; number of VFs to enable
* num_vfs = 0; disable all VFs
*
* Note: SRIOV spec doesn't allow partial VF
* disable, so its all or none.
* disable, so it's all or none.
*/
static ssize_t sriov_numvfs_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct pci_dev *pdev = to_pci_dev(dev);
int num_vfs_enabled = 0;
int num_vfs;
int ret = 0;
u16 total;
int ret;
u16 num_vfs;
if (kstrtoint(buf, 0, &num_vfs) < 0)
return -EINVAL;
ret = kstrtou16(buf, 0, &num_vfs);
if (ret < 0)
return ret;
if (num_vfs > pci_sriov_get_totalvfs(pdev))
return -ERANGE;
if (num_vfs == pdev->sriov->num_VFs)
return count; /* no change */
/* is PF driver loaded w/callback */
if (!pdev->driver || !pdev->driver->sriov_configure) {
dev_info(&pdev->dev,
"Driver doesn't support SRIOV configuration via sysfs\n");
dev_info(&pdev->dev, "Driver doesn't support SRIOV configuration via sysfs\n");
return -ENOSYS;
}
/* if enabling vf's ... */
total = pci_sriov_get_totalvfs(pdev);
/* Requested VFs to enable < totalvfs and none enabled already */
if ((num_vfs > 0) && (num_vfs <= total)) {
if (pdev->sriov->num_VFs == 0) {
num_vfs_enabled =
pdev->driver->sriov_configure(pdev, num_vfs);
if ((num_vfs_enabled >= 0) &&
(num_vfs_enabled != num_vfs)) {
dev_warn(&pdev->dev,
"Only %d VFs enabled\n",
num_vfs_enabled);
return count;
} else if (num_vfs_enabled < 0)
/* error code from driver callback */
return num_vfs_enabled;
} else if (num_vfs == pdev->sriov->num_VFs) {
dev_warn(&pdev->dev,
"%d VFs already enabled; no enable action taken\n",
num_vfs);
return count;
} else {
dev_warn(&pdev->dev,
"%d VFs already enabled. Disable before enabling %d VFs\n",
pdev->sriov->num_VFs, num_vfs);
return -EINVAL;
}
}
/* disable vfs */
if (num_vfs == 0) {
if (pdev->sriov->num_VFs != 0) {
ret = pdev->driver->sriov_configure(pdev, 0);
return ret ? ret : count;
} else {
dev_warn(&pdev->dev,
"All VFs disabled; no disable action taken\n");
return count;
}
/* disable VFs */
ret = pdev->driver->sriov_configure(pdev, 0);
if (ret < 0)
return ret;
return count;
}
dev_err(&pdev->dev,
"Invalid value for number of VFs to enable: %d\n", num_vfs);
/* enable VFs */
if (pdev->sriov->num_VFs) {
dev_warn(&pdev->dev, "%d VFs already enabled. Disable before enabling %d VFs\n",
pdev->sriov->num_VFs, num_vfs);
return -EBUSY;
}
return -EINVAL;
ret = pdev->driver->sriov_configure(pdev, num_vfs);
if (ret < 0)
return ret;
if (ret != num_vfs)
dev_warn(&pdev->dev, "%d VFs requested; only %d enabled\n",
num_vfs, ret);
return count;
}
static struct device_attribute sriov_totalvfs_attr = __ATTR_RO(sriov_totalvfs);