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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2004 Matthew Wilcox <matthew@wil.cx>
3 * Copyright (C) 2004 Intel Corp.
4 *
5 * This code is released under the GNU General Public License version 2.
6 */
7
8/*
9 * mmconfig.c - Low-level direct PCI config space access via MMCONFIG
10 */
11
12#include <linux/pci.h>
13#include <linux/init.h>
Greg Kroah-Hartman54549392005-06-23 17:35:56 -070014#include <linux/acpi.h>
Arjan van de Ven946f2ee2006-04-07 19:49:30 +020015#include <asm/e820.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include "pci.h"
17
Andi Kleen8c30b1a742006-04-07 19:50:12 +020018/* Assume systems with more busses have correct MCFG */
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG))
20
21/* The base address of the last MMCONFIG device accessed */
22static u32 mmcfg_last_accessed_device;
OGAWA Hirofumi8d1c4812006-12-23 10:00:43 +090023static int mmcfg_last_accessed_cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25/*
26 * Functions for accessing PCI configuration space with MMCONFIG accesses
27 */
Andi Kleend6ece542005-12-12 22:17:11 -080028static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029{
Alexey Starikovskiy15a58ed2007-02-02 19:48:22 +030030 struct acpi_mcfg_allocation *cfg;
OGAWA Hirofumi429d5122007-02-13 13:26:20 +010031 int cfg_num;
Greg Kroah-Hartmand57e26c2005-06-23 17:35:56 -070032
Olivier Galibertb7867392007-02-13 13:26:20 +010033 if (seg == 0 && bus < PCI_MMCFG_MAX_CHECK_BUS &&
34 test_bit(PCI_SLOT(devfn) + 32*bus, pci_mmcfg_fallback_slots))
Andi Kleend6ece542005-12-12 22:17:11 -080035 return 0;
36
OGAWA Hirofumi429d5122007-02-13 13:26:20 +010037 for (cfg_num = 0; cfg_num < pci_mmcfg_config_num; cfg_num++) {
Greg Kroah-Hartmand57e26c2005-06-23 17:35:56 -070038 cfg = &pci_mmcfg_config[cfg_num];
OGAWA Hirofumi429d5122007-02-13 13:26:20 +010039 if (cfg->pci_segment == seg &&
40 (cfg->start_bus_number <= bus) &&
Greg Kroah-Hartmand57e26c2005-06-23 17:35:56 -070041 (cfg->end_bus_number >= bus))
Alexey Starikovskiy15a58ed2007-02-02 19:48:22 +030042 return cfg->address;
Greg Kroah-Hartmand57e26c2005-06-23 17:35:56 -070043 }
Andi Kleen31030392006-01-27 02:03:50 +010044
Andi Kleen31030392006-01-27 02:03:50 +010045 /* Fall back to type 0 */
46 return 0;
Greg Kroah-Hartmand57e26c2005-06-23 17:35:56 -070047}
48
Andrew Mortonbe5b7a82006-09-30 23:27:10 -070049/*
50 * This is always called under pci_config_lock
51 */
52static void pci_exp_set_dev_base(unsigned int base, int bus, int devfn)
Greg Kroah-Hartmand57e26c2005-06-23 17:35:56 -070053{
Andi Kleen928cf8c2005-12-12 22:17:10 -080054 u32 dev_base = base | (bus << 20) | (devfn << 12);
OGAWA Hirofumi8d1c4812006-12-23 10:00:43 +090055 int cpu = smp_processor_id();
56 if (dev_base != mmcfg_last_accessed_device ||
57 cpu != mmcfg_last_accessed_cpu) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 mmcfg_last_accessed_device = dev_base;
OGAWA Hirofumi8d1c4812006-12-23 10:00:43 +090059 mmcfg_last_accessed_cpu = cpu;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060 set_fixmap_nocache(FIX_PCIE_MCFG, dev_base);
61 }
62}
63
64static int pci_mmcfg_read(unsigned int seg, unsigned int bus,
65 unsigned int devfn, int reg, int len, u32 *value)
66{
67 unsigned long flags;
Andi Kleen928cf8c2005-12-12 22:17:10 -080068 u32 base;
Linus Torvalds1da177e2005-04-16 15:20:36 -070069
Andi Kleenecc16ba2006-04-11 12:54:48 +020070 if ((bus > 255) || (devfn > 255) || (reg > 4095)) {
Andi Kleen49c93e82006-04-07 19:50:15 +020071 *value = -1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return -EINVAL;
Andi Kleen49c93e82006-04-07 19:50:15 +020073 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070074
Andi Kleend6ece542005-12-12 22:17:11 -080075 base = get_base_addr(seg, bus, devfn);
Andi Kleen928cf8c2005-12-12 22:17:10 -080076 if (!base)
77 return pci_conf1_read(seg,bus,devfn,reg,len,value);
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 spin_lock_irqsave(&pci_config_lock, flags);
80
Andi Kleen928cf8c2005-12-12 22:17:10 -080081 pci_exp_set_dev_base(base, bus, devfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83 switch (len) {
84 case 1:
85 *value = readb(mmcfg_virt_addr + reg);
86 break;
87 case 2:
88 *value = readw(mmcfg_virt_addr + reg);
89 break;
90 case 4:
91 *value = readl(mmcfg_virt_addr + reg);
92 break;
93 }
94
95 spin_unlock_irqrestore(&pci_config_lock, flags);
96
97 return 0;
98}
99
100static int pci_mmcfg_write(unsigned int seg, unsigned int bus,
101 unsigned int devfn, int reg, int len, u32 value)
102{
103 unsigned long flags;
Andi Kleen928cf8c2005-12-12 22:17:10 -0800104 u32 base;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105
Alexey Starikovskiy15a58ed2007-02-02 19:48:22 +0300106 if ((bus > 255) || (devfn > 255) || (reg > 4095))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 return -EINVAL;
108
Andi Kleend6ece542005-12-12 22:17:11 -0800109 base = get_base_addr(seg, bus, devfn);
Andi Kleen928cf8c2005-12-12 22:17:10 -0800110 if (!base)
111 return pci_conf1_write(seg,bus,devfn,reg,len,value);
112
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 spin_lock_irqsave(&pci_config_lock, flags);
114
Andi Kleen928cf8c2005-12-12 22:17:10 -0800115 pci_exp_set_dev_base(base, bus, devfn);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
117 switch (len) {
118 case 1:
119 writeb(value, mmcfg_virt_addr + reg);
120 break;
121 case 2:
122 writew(value, mmcfg_virt_addr + reg);
123 break;
124 case 4:
125 writel(value, mmcfg_virt_addr + reg);
126 break;
127 }
128
129 spin_unlock_irqrestore(&pci_config_lock, flags);
130
131 return 0;
132}
133
134static struct pci_raw_ops pci_mmcfg = {
135 .read = pci_mmcfg_read,
136 .write = pci_mmcfg_write,
137};
138
OGAWA Hirofumi56829d12007-02-13 13:26:20 +0100139int __init pci_mmcfg_arch_reachable(unsigned int seg, unsigned int bus,
140 unsigned int devfn)
141{
142 return get_base_addr(seg, bus, devfn) != 0;
143}
144
Olivier Galibertb7867392007-02-13 13:26:20 +0100145int __init pci_mmcfg_arch_init(void)
Andi Kleend6ece542005-12-12 22:17:11 -0800146{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 printk(KERN_INFO "PCI: Using MMCONFIG\n");
148 raw_pci_ops = &pci_mmcfg;
Olivier Galibertb7867392007-02-13 13:26:20 +0100149 return 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150}