x86/PCI: MMCONFIG: add lookup function

[firefly-linux-kernel-4.4.55.git] / arch / x86 / pci / mmconfig-shared.c

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 71d69b88fa339e0653c5ca39537cfdae1fd2feaf..b19d1e54201ee95a80d8123e9ba26716811c52fe 100644 (file)
--- 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;