Add a dev_flags bit, PCI_DEV_FLAGS_VPD_REF_F0, to access VPD through
function 0 to provide VPD access on other functions. This solves
concurrent access problems on many devices without changing the
attributes exposed in sysfs. Never set this bit on function 0 or
there will be an infinite recursion.
Signed-off-by: Mark Rustad <mark.d.rustad@xxxxxxxxx>
---
Changes in V2:
- Corrected spelling in log message
- Added checks to see that the referenced function 0 is reasonable
Changes in V3:
- Don't leak a device reference
- Check that function 0 has VPD
- Make a helper for the function 0 checks
- Do multifunction check in the quirk
---
drivers/pci/access.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 60 insertions(+), 1 deletion(-)
diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index d9b64a175990..b965c12168b7 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -439,6 +439,56 @@ static const struct pci_vpd_ops pci_vpd_pci22_ops = {
.release = pci_vpd_pci22_release,
};
+static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
+ void *arg)
+{
+ struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn));
+ ssize_t ret;
+
+ if (!tdev)
+ return -ENODEV;
+
+ ret = pci_read_vpd(tdev, pos, count, arg);
+ pci_dev_put(tdev);
+ return ret;
+}
+
+static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count,
+ const void *arg)
+{
+ struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn));
+ ssize_t ret;
+
+ if (!tdev)
+ return -ENODEV;
+
+ ret = pci_write_vpd(tdev, pos, count, arg);
+ pci_dev_put(tdev);
+ return ret;
+}
+
+static const struct pci_vpd_ops pci_vpd_f0_ops = {
+ .read = pci_vpd_f0_read,
+ .write = pci_vpd_f0_write,
+ .release = pci_vpd_pci22_release,
+};
+
+static int pci_vpd_f0_dev_check(struct pci_dev *dev)
+{
+ struct pci_dev *tdev = pci_get_slot(dev->bus, PCI_SLOT(dev->devfn));
+ int ret = 0;
+
+ if (!tdev)
+ return -ENODEV;
+ if (!tdev->vpd || !tdev->multifunction ||
+ dev->class != tdev->class || dev->vendor != tdev->vendor ||
+ dev->device != tdev->device)
+ ret = -ENODEV;
+
+ pci_dev_put(tdev);
+ return ret;
+}
+
int pci_vpd_pci22_init(struct pci_dev *dev)
{
struct pci_vpd_pci22 *vpd;
@@ -447,12 +497,21 @@ int pci_vpd_pci22_init(struct pci_dev *dev)
cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
if (!cap)
return -ENODEV;
+ if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
+ int ret = pci_vpd_f0_dev_check(dev);
+
+ if (ret)
+ return ret;
+ }
vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
if (!vpd)
return -ENOMEM;
vpd->base.len = PCI_VPD_PCI22_SIZE;
- vpd->base.ops = &pci_vpd_pci22_ops;
+ if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
+ vpd->base.ops = &pci_vpd_f0_ops;
+ else
+ vpd->base.ops = &pci_vpd_pci22_ops;
mutex_init(&vpd->lock);
vpd->cap = cap;
vpd->busy = false;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 353db8dc4c6e..194df6d635e6 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -180,6 +180,8 @@ enum pci_dev_flags {
PCI_DEV_FLAGS_NO_BUS_RESET = (__force pci_dev_flags_t) (1 << 6),
/* Do not use PM reset even if device advertises NoSoftRst- */
PCI_DEV_FLAGS_NO_PM_RESET = (__force pci_dev_flags_t) (1 << 7),
+ /* Get VPD from function 0 VPD */
+ PCI_DEV_FLAGS_VPD_REF_F0 = (__force pci_dev_flags_t) (1 << 8),
};
enum pci_irq_reroute_variant {
--
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