PCI: Convert PCIe capability PCIBIOS errors to errno

The PCI config accessors (pci_read_config_word(), et al) return
PCIBIOS_SUCCESSFUL (zero) or positive error values like
PCIBIOS_FUNC_NOT_SUPPORTED.

The PCIe capability accessors (pcie_capability_read_word(), et al)
similarly return PCIBIOS errors, but some callers assume they return
generic errno values like -EINVAL.

For example, the Myri-10G probe function returns a positive PCIBIOS error
if the pcie_capability_clear_and_set_word() in pcie_set_readrq() fails:

  myri10ge_probe
    status = pcie_set_readrq
      return pcie_capability_clear_and_set_word
    if (status)
      return status

A positive return from a PCI driver probe function would cause a "Driver
probe function unexpectedly returned" warning from local_pci_probe()
instead of the desired probe failure.

Convert PCIBIOS errors to generic errno for all callers of:

  pcie_capability_read_word
  pcie_capability_read_dword
  pcie_capability_write_word
  pcie_capability_write_dword
  pcie_capability_set_word
  pcie_capability_set_dword
  pcie_capability_clear_word
  pcie_capability_clear_dword
  pcie_capability_clear_and_set_word
  pcie_capability_clear_and_set_dword

that check the return code for anything other than zero.

[bhelgaas: commit log, squash together]
Suggested-by: Bjorn Helgaas <bjorn@helgaas.com>
Link: https://lore.kernel.org/r/20200615073225.24061-1-refactormyself@gmail.com
Signed-off-by: Bolarinwa Olayemi Saheed <refactormyself@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 16 insertions, 5 deletions

diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index ce096272f52b..45c51aff9c03 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -5688,6 +5688,7 @@ EXPORT_SYMBOL(pcie_get_readrq);
 int pcie_set_readrq(struct pci_dev *dev, int rq)
 {
 	u16 v;
+	int ret;
 
 	if (rq < 128 || rq > 4096 || !is_power_of_2(rq))
 		return -EINVAL;
@@ -5706,8 +5707,10 @@ int pcie_set_readrq(struct pci_dev *dev, int rq)
 
 	v = (ffs(rq) - 8) << 12;
 
-	return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
+	ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
 						  PCI_EXP_DEVCTL_READRQ, v);
+
+	return pcibios_err_to_errno(ret);
 }
 EXPORT_SYMBOL(pcie_set_readrq);
 
@@ -5738,6 +5741,7 @@ EXPORT_SYMBOL(pcie_get_mps);
 int pcie_set_mps(struct pci_dev *dev, int mps)
 {
 	u16 v;
+	int ret;
 
 	if (mps < 128 || mps > 4096 || !is_power_of_2(mps))
 		return -EINVAL;
@@ -5747,8 +5751,10 @@ int pcie_set_mps(struct pci_dev *dev, int mps)
 		return -EINVAL;
 	v <<= 5;
 
-	return pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
+	ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL,
 						  PCI_EXP_DEVCTL_PAYLOAD, v);
+
+	return pcibios_err_to_errno(ret);
 }
 EXPORT_SYMBOL(pcie_set_mps);
 
diff --git a/drivers/pci/pcie/aer.c b/drivers/pci/pcie/aer.c
index 3acf56683915..2dbc1fd2910b 100644
--- a/drivers/pci/pcie/aer.c
+++ b/drivers/pci/pcie/aer.c
@@ -224,20 +224,25 @@ int pcie_aer_is_native(struct pci_dev *dev)
 
 int pci_enable_pcie_error_reporting(struct pci_dev *dev)
 {
+	int rc;
+
 	if (!pcie_aer_is_native(dev))
 		return -EIO;
 
-	return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+	rc = pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+	return pcibios_err_to_errno(rc);
 }
 EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
 
 int pci_disable_pcie_error_reporting(struct pci_dev *dev)
 {
+	int rc;
+
 	if (!pcie_aer_is_native(dev))
 		return -EIO;
 
-	return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
-					  PCI_EXP_AER_FLAGS);
+	rc = pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
+	return pcibios_err_to_errno(rc);
 }
 EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);