x86/PCI: MMCONFIG: add lookup function

This patch factors out the search for an MMCONFIG region, which was
previously implemented in both mmconfig_32 and mmconfig_64.  No functional
change.

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

1 files changed, 12 insertions, 0 deletions

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 71d69b88fa33..b19d1e54201e 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -97,6 +97,18 @@ static __init struct pci_mmcfg_region *pci_mmconfig_add(int segment, int start,
         return new;
 }
 
+struct pci_mmcfg_region *pci_mmconfig_lookup(int segment, int bus)
+{
+        struct pci_mmcfg_region *cfg;
+
+        list_for_each_entry(cfg, &pci_mmcfg_list, list)
+                if (cfg->segment == segment &&
+                    cfg->start_bus <= bus && bus <= cfg->end_bus)
+                        return cfg;
+
+        return NULL;
+}
+
 static const char __init *pci_mmcfg_e7520(void)
 {
         u32 win;