[PATCH] mmconfig: fix unreachable_devices()
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / x86_64 / pci / mmconfig.c
blob65d82736987e600b642646f4d14e515b4fc020fc
1 /*
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.
6 */
8 #include <linux/pci.h>
9 #include <linux/init.h>
10 #include <linux/acpi.h>
11 #include <linux/bitmap.h>
12 #include <asm/e820.h>
14 #include "pci.h"
16 /* Static virtual mapping of the MMCONFIG aperture */
17 struct mmcfg_virt {
18 struct acpi_mcfg_allocation *cfg;
19 char __iomem *virt;
21 static struct mmcfg_virt *pci_mmcfg_virt;
23 static char __iomem *get_virt(unsigned int seg, unsigned bus)
25 struct acpi_mcfg_allocation *cfg;
26 int cfg_num;
28 for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
29 cfg = pci_mmcfg_virt[cfg_num].cfg;
30 if (cfg->pci_segment == seg &&
31 (cfg->start_bus_number <= bus) &&
32 (cfg->end_bus_number >= bus))
33 return pci_mmcfg_virt[cfg_num].virt;
36 /* Fall back to type 0 */
37 return NULL;
40 static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn)
42 char __iomem *addr;
43 if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
44 test_bit(32*bus + PCI_SLOT(devfn), pci_mmcfg_fallback_slots))
45 return NULL;
46 addr = get_virt(seg, bus);
47 if (!addr)
48 return NULL;
49 return addr + ((bus << 20) | (devfn << 12));
52 static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
53 unsigned int devfn, int reg, int len, u32 *value)
55 char __iomem *addr;
57 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
58 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) {
59 *value = -1;
60 return -EINVAL;
63 addr = pci_dev_base(seg, bus, devfn);
64 if (!addr)
65 return pci_conf1_read(seg,bus,devfn,reg,len,value);
67 switch (len) {
68 case 1:
69 *value = readb(addr + reg);
70 break;
71 case 2:
72 *value = readw(addr + reg);
73 break;
74 case 4:
75 *value = readl(addr + reg);
76 break;
79 return 0;
82 static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
83 unsigned int devfn, int reg, int len, u32 value)
85 char __iomem *addr;
87 /* Why do we have this when nobody checks it. How about a BUG()!? -AK */
88 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
89 return -EINVAL;
91 addr = pci_dev_base(seg, bus, devfn);
92 if (!addr)
93 return pci_conf1_write(seg,bus,devfn,reg,len,value);
95 switch (len) {
96 case 1:
97 writeb(value, addr + reg);
98 break;
99 case 2:
100 writew(value, addr + reg);
101 break;
102 case 4:
103 writel(value, addr + reg);
104 break;
107 return 0;
110 static struct pci_raw_ops pci_mmcfg = {
111 .read = pci_mmcfg_read,
112 .write = pci_mmcfg_write,
115 static void __iomem * __init mcfg_ioremap(struct acpi_mcfg_allocation *cfg)
117 void __iomem *addr;
118 u32 size;
120 size = (cfg->end_bus_number + 1) << 20;
121 addr = ioremap_nocache(cfg->address, size);
122 if (addr) {
123 printk(KERN_INFO "PCI: Using MMCONFIG at %Lx - %Lx\n",
124 cfg->address, cfg->address + size - 1);
126 return addr;
129 int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
130 unsigned int devfn)
132 return pci_dev_base(seg, bus, devfn) != NULL;
135 int __init pci_mmcfg_arch_init(void)
137 int i;
138 pci_mmcfg_virt = kmalloc(sizeof(*pci_mmcfg_virt) *
139 pci_mmcfg_config_num, GFP_KERNEL);
140 if (pci_mmcfg_virt == NULL) {
141 printk(KERN_ERR "PCI: Can not allocate memory for mmconfig structures\n");
142 return 0;
145 for (i = 0; i < pci_mmcfg_config_num; ++i) {
146 pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i];
147 pci_mmcfg_virt[i].virt = mcfg_ioremap(&pci_mmcfg_config[i]);
148 if (!pci_mmcfg_virt[i].virt) {
149 printk(KERN_ERR "PCI: Cannot map mmconfig aperture for "
150 "segment %d\n",
151 pci_mmcfg_config[i].pci_segment);
152 return 0;
155 raw_pci_ops = &pci_mmcfg;
156 return 1;