PCI: create common pcibios_err_to_errno

For returning errors out to non-PCI code.  Re-name xen's version.

Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

2 files changed, 29 insertions, 3 deletions

diff --git a/drivers/xen/xen-pciback/conf_space.c b/drivers/xen/xen-pciback/conf_space.c
index 30d7be026c1..46ae0f9f02a 100644
--- a/drivers/xen/xen-pciback/conf_space.c
+++ b/drivers/xen/xen-pciback/conf_space.c
@@ -124,7 +124,7 @@ static inline u32 merge_value(u32 val, u32 new_val, u32 new_val_mask,
         return val;
 }
 
-static int pcibios_err_to_errno(int err)
+static int xen_pcibios_err_to_errno(int err)
 {
         switch (err) {
         case PCIBIOS_SUCCESSFUL:
@@ -202,7 +202,7 @@ out:
                        pci_name(dev), size, offset, value);
 
         *ret_val = value;
-        return pcibios_err_to_errno(err);
+        return xen_pcibios_err_to_errno(err);
 }
 
 int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
@@ -290,7 +290,7 @@ int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size, u32 value)
                 }
         }
 
-        return pcibios_err_to_errno(err);
+        return xen_pcibios_err_to_errno(err);
 }
 
 void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev)
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 9d04599c6bd..a691f62bcf8 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -474,6 +474,32 @@ static inline bool pci_dev_msi_enabled(struct pci_dev *pci_dev) { return false;
 #define PCIBIOS_SET_FAILED              0x88
 #define PCIBIOS_BUFFER_TOO_SMALL        0x89
 
+/*
+ * Translate above to generic errno for passing back through non-pci.
+ */
+static inline int pcibios_err_to_errno(int err)
+{
+        if (err <= PCIBIOS_SUCCESSFUL)
+                return err; /* Assume already errno */
+
+        switch (err) {
+        case PCIBIOS_FUNC_NOT_SUPPORTED:
+                return -ENOENT;
+        case PCIBIOS_BAD_VENDOR_ID:
+                return -EINVAL;
+        case PCIBIOS_DEVICE_NOT_FOUND:
+                return -ENODEV;
+        case PCIBIOS_BAD_REGISTER_NUMBER:
+                return -EFAULT;
+        case PCIBIOS_SET_FAILED:
+                return -EIO;
+        case PCIBIOS_BUFFER_TOO_SMALL:
+                return -ENOSPC;
+        }
+
+        return -ENOTTY;
+}
+
 /* Low-level architecture-dependent routines */
 
 struct pci_ops {