[PATCH] PCI/IOV: Expose error return to dmesg

From: Liming Wu
Date: Tue Dec 13 2022 - 03:16:42 EST


There are many errors returned during the initialization of sriov,
such as -EIO/-ENOMEM, but they are not exposed to dmesg.
Let's expose the real errors to the user.

In addition, -ENODEV doesn't make much sense and is not returned
just like any other capabilities.

Signed-off-by: Liming Wu <liming.wu@xxxxxxxxxxxxxxx>
---
drivers/pci/iov.c | 9 ++++++---
drivers/pci/pci.h | 2 --
drivers/pci/probe.c | 6 +++++-
3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 952217572113..519aa2b48236 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -767,8 +767,11 @@ static int sriov_init(struct pci_dev *dev, int pos)
pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, ctrl);

pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total);
- if (!total)
+ if (!total) {
+ pci_info(dev, "SR-IOV capability is enabled but has %d VFs)\n",
+ total);
return 0;
+ }

pci_read_config_dword(dev, pos + PCI_SRIOV_SUP_PGSIZE, &pgsz);
i = PAGE_SHIFT > 12 ? PAGE_SHIFT - 12 : 0;
@@ -899,13 +902,13 @@ int pci_iov_init(struct pci_dev *dev)
int pos;

if (!pci_is_pcie(dev))
- return -ENODEV;
+ return;

pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_SRIOV);
if (pos)
return sriov_init(dev, pos);

- return -ENODEV;
+ return;
}

/**
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index b1ebb7ab8805..c4836104f697 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -485,10 +485,8 @@ extern const struct attribute_group sriov_vf_dev_attr_group;
#else
static inline int pci_iov_init(struct pci_dev *dev)
{
- return -ENODEV;
}
static inline void pci_iov_release(struct pci_dev *dev)
-
{
}
static inline void pci_iov_remove(struct pci_dev *dev)
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index b66fa42c4b1f..c951e0a50388 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -2449,6 +2449,7 @@ void pcie_report_downtraining(struct pci_dev *dev)

static void pci_init_capabilities(struct pci_dev *dev)
{
+ int ret;
pci_ea_init(dev); /* Enhanced Allocation */
pci_msi_init(dev); /* Disable MSI */
pci_msix_init(dev); /* Disable MSI-X */
@@ -2459,7 +2460,10 @@ static void pci_init_capabilities(struct pci_dev *dev)
pci_pm_init(dev); /* Power Management */
pci_vpd_init(dev); /* Vital Product Data */
pci_configure_ari(dev); /* Alternative Routing-ID Forwarding */
- pci_iov_init(dev); /* Single Root I/O Virtualization */
+ ret = pci_iov_init(dev); /* Single Root I/O Virtualization */
+ if (ret)
+ pci_err(dev, "SR-IOV: init failed (%d)\n", ret);
+
pci_ats_init(dev); /* Address Translation Services */
pci_pri_init(dev); /* Page Request Interface */
pci_pasid_init(dev); /* Process Address Space ID */
--
2.25.1