2 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
4 * This is an 64bit optimized version that always keeps the full mmconfig
5 * space mapped. This allows lockless config space operation.
9 #include <linux/init.h>
10 #include <linux/acpi.h>
11 #include <linux/bitmap.h>
13 #include <asm/pci_x86.h>
15 #define PREFIX "PCI: "
17 static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
19 struct pci_mmcfg_region *cfg = pci_mmconfig_lookup(seg, bus);
22 return cfg->virt + (PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12));
26 static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
27 unsigned int devfn, int reg, int len, u32 *value)
31 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
32 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
37 addr = pci_dev_base(seg, bus, devfn);
43 *value = mmio_config_readb(addr + reg);
46 *value = mmio_config_readw(addr + reg);
49 *value = mmio_config_readl(addr + reg);
56 static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
57 unsigned int devfn, int reg, int len, u32 value)
61 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
62 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
65 addr = pci_dev_base(seg, bus, devfn);
71 mmio_config_writeb(addr + reg, value);
74 mmio_config_writew(addr + reg, value);
77 mmio_config_writel(addr + reg, value);
84 static struct pci_raw_ops pci_mmcfg = {
85 .read = pci_mmcfg_read,
86 .write = pci_mmcfg_write,
89 static void __iomem * __init mcfg_ioremap(struct pci_mmcfg_region *cfg)
95 start = cfg->address + PCI_MMCFG_BUS_OFFSET(cfg->start_bus);
96 num_buses = cfg->end_bus - cfg->start_bus + 1;
97 size = PCI_MMCFG_BUS_OFFSET(num_buses);
98 addr = ioremap_nocache(start, size);
100 addr -= PCI_MMCFG_BUS_OFFSET(cfg->start_bus);
104 int __init pci_mmcfg_arch_init(void)
106 struct pci_mmcfg_region *cfg;
108 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
109 cfg->virt = mcfg_ioremap(cfg);
111 printk(KERN_ERR PREFIX "can't map MMCONFIG at %pR\n",
113 pci_mmcfg_arch_free();
117 raw_pci_ext_ops = &pci_mmcfg;
121 void __init pci_mmcfg_arch_free(void)
123 struct pci_mmcfg_region *cfg;
125 list_for_each_entry(cfg, &pci_mmcfg_list, list) {
127 iounmap(cfg->virt + PCI_MMCFG_BUS_OFFSET(cfg->start_bus));