PCI: handle positive error codes

Callers expect pci_user_{read,write}_config_*() to indicate errors by
returning negative values.  Prior to this change, the indicated routines
could return positive error codes (e.g. PCIBIOS_BAD_REGISTER_NUMBER)
which callers would mistakenly interpret as success.

This change converts any non-zero return from the mentioned routines
into unambiguous negative value return codes.

Signed-off-by: Greg Thelen <gthelen@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 13 insertions, 3 deletions

diff --git a/drivers/pci/access.c b/drivers/pci/access.c
index 0c1f20f570a4..fdaa42aac7c6 100644
--- a/drivers/pci/access.c
+++ b/drivers/pci/access.c
@@ -143,33 +143,41 @@ static noinline void pci_wait_ucfg(struct pci_dev *dev)
         __remove_wait_queue(&pci_ucfg_wait, &wait);
 }
 
+/* Returns 0 on success, negative values indicate error. */
 #define PCI_USER_READ_CONFIG(size,type)                                 \
 int pci_user_read_config_##size                                         \
         (struct pci_dev *dev, int pos, type *val)                       \
 {                                                                       \
         int ret = 0;                                                    \
         u32 data = -1;                                                  \
-        if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
+        if (PCI_##size##_BAD)                                           \
+                return -EINVAL;                                         \
         raw_spin_lock_irq(&pci_lock);                           \
         if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev);       \
         ret = dev->bus->ops->read(dev->bus, dev->devfn,                 \
                                         pos, sizeof(type), &data);      \
         raw_spin_unlock_irq(&pci_lock);                         \
         *val = (type)data;                                              \
+        if (ret > 0)                                                    \
+                ret = -EINVAL;                                          \
         return ret;                                                     \
 }
 
+/* Returns 0 on success, negative values indicate error. */
 #define PCI_USER_WRITE_CONFIG(size,type)                                \
 int pci_user_write_config_##size                                        \
         (struct pci_dev *dev, int pos, type val)                        \
 {                                                                       \
         int ret = -EIO;                                                 \
-        if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER;       \
+        if (PCI_##size##_BAD)                                           \
+                return -EINVAL;                                         \
         raw_spin_lock_irq(&pci_lock);                           \
         if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev);       \
         ret = dev->bus->ops->write(dev->bus, dev->devfn,                \
                                         pos, sizeof(type), val);        \
         raw_spin_unlock_irq(&pci_lock);                         \
+        if (ret > 0)                                                    \
+                ret = -EINVAL;                                          \
         return ret;                                                     \
 }
 
@@ -197,6 +205,8 @@ struct pci_vpd_pci22 {
  * This code has to spin since there is no other notification from the PCI
  * hardware. Since the VPD is often implemented by serial attachment to an
  * EEPROM, it may take many milliseconds to complete.
+ *
+ * Returns 0 on success, negative values indicate error.
  */
 static int pci_vpd_pci22_wait(struct pci_dev *dev)
 {
@@ -212,7 +222,7 @@ static int pci_vpd_pci22_wait(struct pci_dev *dev)
         for (;;) {
                 ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
                                                 &status);
-                if (ret)
+                if (ret < 0)
                         return ret;
 
                 if ((status & PCI_VPD_ADDR_F) == vpd->flag) {