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>
diff --git a/drivers/dma/ioat/init.c b/drivers/dma/ioat/init.c
index 58d1356..9a6a9ec 100644
--- a/drivers/dma/ioat/init.c
+++ b/drivers/dma/ioat/init.c
@@ -1195,13 +1195,13 @@ static int ioat3_dma_probe(struct ioatdma_device *ioat_dma, int dca)
 	/* disable relaxed ordering */
 	err = pcie_capability_read_word(pdev, IOAT_DEVCTRL_OFFSET, &val16);
 	if (err)
-		return err;
+		return pcibios_err_to_errno(err);
 
 	/* clear relaxed ordering enable */
 	val16 &= ~IOAT_DEVCTRL_ROE;
 	err = pcie_capability_write_word(pdev, IOAT_DEVCTRL_OFFSET, val16);
 	if (err)
-		return err;
+		return pcibios_err_to_errno(err);
 
 	if (ioat_dma->cap & IOAT_CAP_DPS)
 		writeb(ioat_pending_level + 1,