Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 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-Hartman | 5454939 | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 14 | #include <linux/acpi.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include "pci.h" |
| 16 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 17 | #define mmcfg_virt_addr ((void __iomem *) fix_to_virt(FIX_PCIE_MCFG)) |
| 18 | |
| 19 | /* The base address of the last MMCONFIG device accessed */ |
| 20 | static u32 mmcfg_last_accessed_device; |
| 21 | |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 22 | static DECLARE_BITMAP(fallback_slots, 32); |
| 23 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | /* |
| 25 | * Functions for accessing PCI configuration space with MMCONFIG accesses |
| 26 | */ |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 27 | static u32 get_base_addr(unsigned int seg, int bus, unsigned devfn) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | { |
Greg Kroah-Hartman | d57e26c | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 29 | int cfg_num = -1; |
| 30 | struct acpi_table_mcfg_config *cfg; |
| 31 | |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 32 | if (seg == 0 && bus == 0 && |
| 33 | test_bit(PCI_SLOT(devfn), fallback_slots)) |
| 34 | return 0; |
| 35 | |
Greg Kroah-Hartman | d57e26c | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 36 | while (1) { |
| 37 | ++cfg_num; |
| 38 | if (cfg_num >= pci_mmcfg_config_num) { |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 39 | /* Not found - fallback to type 1 */ |
| 40 | return 0; |
Greg Kroah-Hartman | d57e26c | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 41 | } |
| 42 | cfg = &pci_mmcfg_config[cfg_num]; |
| 43 | if (cfg->pci_segment_group_number != seg) |
| 44 | continue; |
| 45 | if ((cfg->start_bus_number <= bus) && |
| 46 | (cfg->end_bus_number >= bus)) |
| 47 | return cfg->base_address; |
| 48 | } |
| 49 | } |
| 50 | |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 51 | static inline void pci_exp_set_dev_base(unsigned int base, int bus, int devfn) |
Greg Kroah-Hartman | d57e26c | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 52 | { |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 53 | u32 dev_base = base | (bus << 20) | (devfn << 12); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | if (dev_base != mmcfg_last_accessed_device) { |
| 55 | mmcfg_last_accessed_device = dev_base; |
| 56 | set_fixmap_nocache(FIX_PCIE_MCFG, dev_base); |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | static int pci_mmcfg_read(unsigned int seg, unsigned int bus, |
| 61 | unsigned int devfn, int reg, int len, u32 *value) |
| 62 | { |
| 63 | unsigned long flags; |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 64 | u32 base; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 65 | |
| 66 | if (!value || (bus > 255) || (devfn > 255) || (reg > 4095)) |
| 67 | return -EINVAL; |
| 68 | |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 69 | base = get_base_addr(seg, bus, devfn); |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 70 | if (!base) |
| 71 | return pci_conf1_read(seg,bus,devfn,reg,len,value); |
| 72 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | spin_lock_irqsave(&pci_config_lock, flags); |
| 74 | |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 75 | pci_exp_set_dev_base(base, bus, devfn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | |
| 77 | switch (len) { |
| 78 | case 1: |
| 79 | *value = readb(mmcfg_virt_addr + reg); |
| 80 | break; |
| 81 | case 2: |
| 82 | *value = readw(mmcfg_virt_addr + reg); |
| 83 | break; |
| 84 | case 4: |
| 85 | *value = readl(mmcfg_virt_addr + reg); |
| 86 | break; |
| 87 | } |
| 88 | |
| 89 | spin_unlock_irqrestore(&pci_config_lock, flags); |
| 90 | |
| 91 | return 0; |
| 92 | } |
| 93 | |
| 94 | static int pci_mmcfg_write(unsigned int seg, unsigned int bus, |
| 95 | unsigned int devfn, int reg, int len, u32 value) |
| 96 | { |
| 97 | unsigned long flags; |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 98 | u32 base; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 99 | |
| 100 | if ((bus > 255) || (devfn > 255) || (reg > 4095)) |
| 101 | return -EINVAL; |
| 102 | |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 103 | base = get_base_addr(seg, bus, devfn); |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 104 | if (!base) |
| 105 | return pci_conf1_write(seg,bus,devfn,reg,len,value); |
| 106 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | spin_lock_irqsave(&pci_config_lock, flags); |
| 108 | |
Andi Kleen | 928cf8c | 2005-12-12 22:17:10 -0800 | [diff] [blame] | 109 | pci_exp_set_dev_base(base, bus, devfn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | |
| 111 | switch (len) { |
| 112 | case 1: |
| 113 | writeb(value, mmcfg_virt_addr + reg); |
| 114 | break; |
| 115 | case 2: |
| 116 | writew(value, mmcfg_virt_addr + reg); |
| 117 | break; |
| 118 | case 4: |
| 119 | writel(value, mmcfg_virt_addr + reg); |
| 120 | break; |
| 121 | } |
| 122 | |
| 123 | spin_unlock_irqrestore(&pci_config_lock, flags); |
| 124 | |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static struct pci_raw_ops pci_mmcfg = { |
| 129 | .read = pci_mmcfg_read, |
| 130 | .write = pci_mmcfg_write, |
| 131 | }; |
| 132 | |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 133 | /* K8 systems have some devices (typically in the builtin northbridge) |
| 134 | that are only accessible using type1 |
| 135 | Normally this can be expressed in the MCFG by not listing them |
| 136 | and assigning suitable _SEGs, but this isn't implemented in some BIOS. |
| 137 | Instead try to discover all devices on bus 0 that are unreachable using MM |
| 138 | and fallback for them. |
| 139 | We only do this for bus 0/seg 0 */ |
| 140 | static __init void unreachable_devices(void) |
| 141 | { |
| 142 | int i; |
| 143 | unsigned long flags; |
| 144 | |
| 145 | for (i = 0; i < 32; i++) { |
| 146 | u32 val1; |
| 147 | u32 addr; |
| 148 | |
| 149 | pci_conf1_read(0, 0, PCI_DEVFN(i, 0), 0, 4, &val1); |
| 150 | if (val1 == 0xffffffff) |
| 151 | continue; |
| 152 | |
| 153 | /* Locking probably not needed, but safer */ |
| 154 | spin_lock_irqsave(&pci_config_lock, flags); |
| 155 | addr = get_base_addr(0, 0, PCI_DEVFN(i, 0)); |
| 156 | if (addr != 0) |
| 157 | pci_exp_set_dev_base(addr, 0, PCI_DEVFN(i, 0)); |
| 158 | if (addr == 0 || readl((u32 *)addr) != val1) |
| 159 | set_bit(i, fallback_slots); |
| 160 | spin_unlock_irqrestore(&pci_config_lock, flags); |
| 161 | } |
| 162 | } |
| 163 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | static int __init pci_mmcfg_init(void) |
| 165 | { |
| 166 | if ((pci_probe & PCI_PROBE_MMCONF) == 0) |
| 167 | goto out; |
Greg Kroah-Hartman | 5454939 | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 168 | |
| 169 | acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg); |
| 170 | if ((pci_mmcfg_config_num == 0) || |
| 171 | (pci_mmcfg_config == NULL) || |
| 172 | (pci_mmcfg_config[0].base_address == 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | goto out; |
| 174 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 175 | printk(KERN_INFO "PCI: Using MMCONFIG\n"); |
| 176 | raw_pci_ops = &pci_mmcfg; |
| 177 | pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; |
| 178 | |
Andi Kleen | d6ece54 | 2005-12-12 22:17:11 -0800 | [diff] [blame^] | 179 | unreachable_devices(); |
| 180 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 181 | out: |
| 182 | return 0; |
| 183 | } |
| 184 | |
| 185 | arch_initcall(pci_mmcfg_init); |