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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/x86_64/pci/mmconfig.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/x86_64/pci/mmconfig.c')
-rw-r--r--arch/x86_64/pci/mmconfig.c104
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/x86_64/pci/mmconfig.c b/arch/x86_64/pci/mmconfig.c
new file mode 100644
index 000000000000..b693c232fd07
--- /dev/null
+++ b/arch/x86_64/pci/mmconfig.c
@@ -0,0 +1,104 @@
1/*
2 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
3 *
4 * This is an 64bit optimized version that always keeps the full mmconfig
5 * space mapped. This allows lockless config space operation.
6 */
7
8#include <linux/pci.h>
9#include <linux/init.h>
10#include "pci.h"
11
12#define MMCONFIG_APER_SIZE (256*1024*1024)
13
14/* The physical address of the MMCONFIG aperture. Set from ACPI tables. */
15u32 pci_mmcfg_base_addr;
16
17/* Static virtual mapping of the MMCONFIG aperture */
18char *pci_mmcfg_virt;
19
20static inline char *pci_dev_base(unsigned int bus, unsigned int devfn)
21{
22 return pci_mmcfg_virt + ((bus << 20) | (devfn << 12));
23}
24
25static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
26 unsigned int devfn, int reg, int len, u32 *value)
27{
28 char *addr = pci_dev_base(bus, devfn);
29
30 if (unlikely(!value || (bus > 255) || (devfn > 255) || (reg > 4095)))
31 return -EINVAL;
32
33 switch (len) {
34 case 1:
35 *value = readb(addr + reg);
36 break;
37 case 2:
38 *value = readw(addr + reg);
39 break;
40 case 4:
41 *value = readl(addr + reg);
42 break;
43 }
44
45 return 0;
46}
47
48static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
49 unsigned int devfn, int reg, int len, u32 value)
50{
51 char *addr = pci_dev_base(bus,devfn);
52
53 if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095)))
54 return -EINVAL;
55
56 switch (len) {
57 case 1:
58 writeb(value, addr + reg);
59 break;
60 case 2:
61 writew(value, addr + reg);
62 break;
63 case 4:
64 writel(value, addr + reg);
65 break;
66 }
67
68 return 0;
69}
70
71static struct pci_raw_ops pci_mmcfg = {
72 .read = pci_mmcfg_read,
73 .write = pci_mmcfg_write,
74};
75
76static int __init pci_mmcfg_init(void)
77{
78 if ((pci_probe & PCI_PROBE_MMCONF) == 0)
79 return 0;
80 if (!pci_mmcfg_base_addr)
81 return 0;
82
83 /* Kludge for now. Don't use mmconfig on AMD systems because
84 those have some busses where mmconfig doesn't work,
85 and we don't parse ACPI MCFG well enough to handle that.
86 Remove when proper handling is added. */
87 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
88 return 0;
89
90 /* RED-PEN i386 doesn't do _nocache right now */
91 pci_mmcfg_virt = ioremap_nocache(pci_mmcfg_base_addr, MMCONFIG_APER_SIZE);
92 if (!pci_mmcfg_virt) {
93 printk("PCI: Cannot map mmconfig aperture\n");
94 return 0;
95 }
96
97 printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_base_addr);
98 raw_pci_ops = &pci_mmcfg;
99 pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
100
101 return 0;
102}
103
104arch_initcall(pci_mmcfg_init);