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>

diff --git a/arch/x86/pci/early.c b/arch/x86/pci/early.c
index f6adf2c..c1a2cd5 100644 (file)
--- 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;
+                               }
                        }
                }
        }