x86/PCI: refine __pci_mmcfg_init() for better code readability

Refine __pci_mmcfg_init() for better code readability.

Reviewed-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

1 files changed, 21 insertions, 25 deletions

diff --git a/arch/x86/pci/mmconfig-shared.c b/arch/x86/pci/mmconfig-shared.c
index 332fabdeff43..ffe72b9d6869 100644
--- a/arch/x86/pci/mmconfig-shared.c
+++ b/arch/x86/pci/mmconfig-shared.c
@@ -544,8 +544,6 @@ static void __init pci_mmcfg_reject_broken(int early)
         }
 }
 
-static int __initdata known_bridge;
-
 static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
                                         struct acpi_mcfg_allocation *cfg)
 {
@@ -617,28 +615,7 @@ static int __init pci_parse_mcfg(struct acpi_table_header *header)
 
 static void __init __pci_mmcfg_init(int early)
 {
-        /* MMCONFIG disabled */
-        if ((pci_probe & PCI_PROBE_MMCONF) == 0)
-                return;
-
-        /* MMCONFIG already enabled */
-        if (!early && !(pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF))
-                return;
-
-        /* for late to exit */
-        if (known_bridge)
-                return;
-
-        if (early) {
-                if (pci_mmcfg_check_hostbridge())
-                        known_bridge = 1;
-        }
-
-        if (!known_bridge)
-                acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
-
         pci_mmcfg_reject_broken(early);
-
         if (list_empty(&pci_mmcfg_list))
                 return;
 
@@ -660,14 +637,33 @@ static void __init __pci_mmcfg_init(int early)
         }
 }
 
+static int __initdata known_bridge;
+
 void __init pci_mmcfg_early_init(void)
 {
-        __pci_mmcfg_init(1);
+        if (pci_probe & PCI_PROBE_MMCONF) {
+                if (pci_mmcfg_check_hostbridge())
+                        known_bridge = 1;
+                else
+                        acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
+                __pci_mmcfg_init(1);
+        }
 }
 
 void __init pci_mmcfg_late_init(void)
 {
-        __pci_mmcfg_init(0);
+        /* MMCONFIG disabled */
+        if ((pci_probe & PCI_PROBE_MMCONF) == 0)
+                return;
+
+        if (known_bridge)
+                return;
+
+        /* MMCONFIG hasn't been enabled yet, try again */
+        if (pci_probe & PCI_PROBE_MASK & ~PCI_PROBE_MMCONF) {
+                acpi_sfi_table_parse(ACPI_SIG_MCFG, pci_parse_mcfg);
+                __pci_mmcfg_init(0);
+        }
 }
 
 static int __init pci_mmcfg_late_insert_resources(void)