x86/PCI: MMCONFIG: add PCI_MMCFG_BUS_OFFSET() to factor common expression

This factors out the common "bus << 20" expression used when computing the
MMCONFIG address.

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, 7 insertions, 8 deletions

diff --git a/arch/x86/pci/mmconfig_64.c b/arch/x86/pci/mmconfig_64.c
index 94349f8b2f96..8588711924cc 100644
--- a/arch/x86/pci/mmconfig_64.c
+++ b/arch/x86/pci/mmconfig_64.c
@@ -43,7 +43,7 @@ static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned i
         addr = get_virt(seg, bus);
         if (!addr)
                 return NULL;
-        return addr + ((bus << 20) | (devfn << 12));
+        return addr + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
 }
 
 static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
@@ -113,17 +113,16 @@ static void __iomem * __init mcfg_ioremap(struct acpi_mcfg_allocation *cfg)
 {
         void __iomem *addr;
         u64 start, size;
+        int num_buses;
 
-        start = cfg->start_bus_number;
-        start <<= 20;
-        start += cfg->address;
-        size = cfg->end_bus_number + 1 - cfg->start_bus_number;
-        size <<= 20;
+        start = cfg->address + PCI_MMCFG_BUS_OFFSET(cfg->start_bus_number);
+        num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
+        size = PCI_MMCFG_BUS_OFFSET(num_buses);
         addr = ioremap_nocache(start, size);
         if (addr) {
                 printk(KERN_INFO "PCI: Using MMCONFIG at %Lx - %Lx\n",
                        start, start + size - 1);
-                addr -= cfg->start_bus_number << 20;
+                addr -= PCI_MMCFG_BUS_OFFSET(cfg->start_bus_number);
         }
         return addr;
 }
@@ -162,7 +161,7 @@ void __init pci_mmcfg_arch_free(void)
 
         for (i = 0; i < pci_mmcfg_config_num; ++i) {
                 if (pci_mmcfg_virt[i].virt) {
-                        iounmap(pci_mmcfg_virt[i].virt + (pci_mmcfg_virt[i].cfg->start_bus_number << 20));
+                        iounmap(pci_mmcfg_virt[i].virt + PCI_MMCFG_BUS_OFFSET(pci_mmcfg_virt[i].cfg->start_bus_number));
                         pci_mmcfg_virt[i].virt = NULL;
                         pci_mmcfg_virt[i].cfg = NULL;
                 }