PCI/x86: make early dump handle multi-function devices

The early "dump PCI config space" code skips many multi-function
devices.  This patch fixes that, so it dumps all devices in PCI
domain 0.

We should not skip the rest of the functions if CLASS_REVISION is
0xffffffff.  Often multi-function devices have gaps in the function ID
space, e.g., 1c.0 and 1c.2 exist but 1c.1 doesn't.  The CLASS_REVISION
of the non-existent 1c.1 function will appear to be 0xffffffff.

We should only look at the HEADER_TYPE of function zero.  Often the
"multi-function" is set in function zero, but not in other functions.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c
index f6adf2c6d751..c1a2cd541724 100644
--- a/arch/x86/pci/early.c
+++ b/arch/x86/pci/early.c
@@ -96,18 +96,21 @@ void early_dump_pci_devices(void)
                         for (func = 0; func < 8; func++) {
                                 u32 class;
                                 u8 type;
+
                                 class = read_pci_config(bus, slot, func,
                                                         PCI_CLASS_REVISION);
                                 if (class == 0xffffffff)
-                                        break;
+                                        continue;
 
                                 early_dump_pci_device(bus, slot, func);
 
-                                /* No multi-function device? */
-                                type = read_pci_config_byte(bus, slot, func,
+                                if (func == 0) {
+                                        type = read_pci_config_byte(bus, slot,
+                                                                    func,
                                                                PCI_HEADER_TYPE);
-                                if (!(type & 0x80))
-                                        break;
+                                        if (!(type & 0x80))
+                                                break;
+                                }
                         }
                 }
         }