2 * Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx>
3 * Copyright (C) 2004 Intel Corp.
5 * This code is released under the GNU General Public License version 2.
9 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
12 #include <linux/pci.h>
13 #include <linux/init.h>
15 #include <asm/pci_x86.h>
16 #include <acpi/acpi.h>
18 /* Assume systems with more busses have correct MCFG */
19 #define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
21 /* The base address of the last MMCONFIG device accessed */
22 static u32 mmcfg_last_accessed_device;
23 static int mmcfg_last_accessed_cpu;
26 * Functions for accessing PCI configuration space with MMCONFIG accesses
28 static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
30 struct pci_mmcfg_region *cfg;
32 list_for_each_entry(cfg, &pci_mmcfg_list, list)
33 if (cfg->segment == seg &&
34 (cfg->start_bus <= bus) &&
35 (cfg->end_bus >= bus))
38 /* Fall back to type 0 */
43 * This is always called under pci_config_lock
45 static void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)
47 u32 dev_base = base | PCI_MMCFG_BUS_OFFSET(bus) | (devfn << 12);
48 int cpu = smp_processor_id();
49 if (dev_base != mmcfg_last_accessed_device ||
50 cpu != mmcfg_last_accessed_cpu) {
51 mmcfg_last_accessed_device = dev_base;
52 mmcfg_last_accessed_cpu = cpu;
53 set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
57 static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
58 unsigned int devfn, int reg, int len, u32 *value)
63 if ((bus > 255) || (devfn > 255) || (reg > 4095)) {
68 base = get_base_addr(seg, bus, devfn);
72 spin_lock_irqsave(&pci_config_lock, flags);
74 pci_exp_set_dev_base(base, bus, devfn);
78 *value = mmio_config_readb(mmcfg_virt_addr + reg);
81 *value = mmio_config_readw(mmcfg_virt_addr + reg);
84 *value = mmio_config_readl(mmcfg_virt_addr + reg);
87 spin_unlock_irqrestore(&pci_config_lock, flags);
92 static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
93 unsigned int devfn, int reg, int len, u32 value)
98 if ((bus > 255) || (devfn > 255) || (reg > 4095))
101 base = get_base_addr(seg, bus, devfn);
105 spin_lock_irqsave(&pci_config_lock, flags);
107 pci_exp_set_dev_base(base, bus, devfn);
111 mmio_config_writeb(mmcfg_virt_addr + reg, value);
114 mmio_config_writew(mmcfg_virt_addr + reg, value);
117 mmio_config_writel(mmcfg_virt_addr + reg, value);
120 spin_unlock_irqrestore(&pci_config_lock, flags);
125 static struct pci_raw_ops pci_mmcfg = {
126 .read = pci_mmcfg_read,
127 .write = pci_mmcfg_write,
130 int __init pci_mmcfg_arch_init(void)
132 printk(KERN_INFO "PCI: Using MMCONFIG for extended config space\n");
133 raw_pci_ext_ops = &pci_mmcfg;
137 void __init pci_mmcfg_arch_free(void)