Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Greg Kroah-Hartman | 5454939 | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 10 | #include <linux/acpi.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include "pci.h" |
| 12 | |
| 13 | #define MMCONFIG_APER_SIZE (256*1024*1024) |
| 14 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | /* Static virtual mapping of the MMCONFIG aperture */ |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 16 | struct mmcfg_virt { |
| 17 | struct acpi_table_mcfg_config *cfg; |
| 18 | char *virt; |
| 19 | }; |
| 20 | static struct mmcfg_virt *pci_mmcfg_virt; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 22 | static char *get_virt(unsigned int seg, int bus) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 23 | { |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 24 | int cfg_num = -1; |
| 25 | struct acpi_table_mcfg_config *cfg; |
| 26 | |
| 27 | while (1) { |
| 28 | ++cfg_num; |
| 29 | if (cfg_num >= pci_mmcfg_config_num) { |
| 30 | /* something bad is going on, no cfg table is found. */ |
| 31 | /* so we fall back to the old way we used to do this */ |
| 32 | /* and just rely on the first entry to be correct. */ |
| 33 | return pci_mmcfg_virt[0].virt; |
| 34 | } |
| 35 | cfg = pci_mmcfg_virt[cfg_num].cfg; |
| 36 | if (cfg->pci_segment_group_number != seg) |
| 37 | continue; |
| 38 | if ((cfg->start_bus_number <= bus) && |
| 39 | (cfg->end_bus_number >= bus)) |
| 40 | return pci_mmcfg_virt[cfg_num].virt; |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | static inline char *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn) |
| 45 | { |
| 46 | |
| 47 | return get_virt(seg, bus) + ((bus << 20) | (devfn << 12)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 48 | } |
| 49 | |
| 50 | static int pci_mmcfg_read(unsigned int seg, unsigned int bus, |
| 51 | unsigned int devfn, int reg, int len, u32 *value) |
| 52 | { |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 53 | char *addr = pci_dev_base(seg, bus, devfn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | |
| 55 | if (unlikely(!value || (bus > 255) || (devfn > 255) || (reg > 4095))) |
| 56 | return -EINVAL; |
| 57 | |
| 58 | switch (len) { |
| 59 | case 1: |
| 60 | *value = readb(addr + reg); |
| 61 | break; |
| 62 | case 2: |
| 63 | *value = readw(addr + reg); |
| 64 | break; |
| 65 | case 4: |
| 66 | *value = readl(addr + reg); |
| 67 | break; |
| 68 | } |
| 69 | |
| 70 | return 0; |
| 71 | } |
| 72 | |
| 73 | static int pci_mmcfg_write(unsigned int seg, unsigned int bus, |
| 74 | unsigned int devfn, int reg, int len, u32 value) |
| 75 | { |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 76 | char *addr = pci_dev_base(seg, bus, devfn); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 77 | |
| 78 | if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) |
| 79 | return -EINVAL; |
| 80 | |
| 81 | switch (len) { |
| 82 | case 1: |
| 83 | writeb(value, addr + reg); |
| 84 | break; |
| 85 | case 2: |
| 86 | writew(value, addr + reg); |
| 87 | break; |
| 88 | case 4: |
| 89 | writel(value, addr + reg); |
| 90 | break; |
| 91 | } |
| 92 | |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static struct pci_raw_ops pci_mmcfg = { |
| 97 | .read = pci_mmcfg_read, |
| 98 | .write = pci_mmcfg_write, |
| 99 | }; |
| 100 | |
| 101 | static int __init pci_mmcfg_init(void) |
| 102 | { |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 103 | int i; |
| 104 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | if ((pci_probe & PCI_PROBE_MMCONF) == 0) |
| 106 | return 0; |
Greg Kroah-Hartman | 5454939 | 2005-06-23 17:35:56 -0700 | [diff] [blame] | 107 | |
| 108 | acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg); |
| 109 | if ((pci_mmcfg_config_num == 0) || |
| 110 | (pci_mmcfg_config == NULL) || |
| 111 | (pci_mmcfg_config[0].base_address == 0)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 112 | return 0; |
| 113 | |
| 114 | /* Kludge for now. Don't use mmconfig on AMD systems because |
| 115 | those have some busses where mmconfig doesn't work, |
| 116 | and we don't parse ACPI MCFG well enough to handle that. |
| 117 | Remove when proper handling is added. */ |
| 118 | if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) |
| 119 | return 0; |
| 120 | |
| 121 | /* RED-PEN i386 doesn't do _nocache right now */ |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 122 | pci_mmcfg_virt = kmalloc(sizeof(*pci_mmcfg_virt) * pci_mmcfg_config_num, GFP_KERNEL); |
| 123 | if (pci_mmcfg_virt == NULL) { |
| 124 | printk("PCI: Can not allocate memory for mmconfig structures\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 125 | return 0; |
Greg Kroah-Hartman | 1cde8a1 | 2005-06-23 17:35:56 -0700 | [diff] [blame^] | 126 | } |
| 127 | for (i = 0; i < pci_mmcfg_config_num; ++i) { |
| 128 | pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i]; |
| 129 | pci_mmcfg_virt[i].virt = ioremap_nocache(pci_mmcfg_config[i].base_address, MMCONFIG_APER_SIZE); |
| 130 | if (!pci_mmcfg_virt[i].virt) { |
| 131 | printk("PCI: Cannot map mmconfig aperture for segment %d\n", |
| 132 | pci_mmcfg_config[i].pci_segment_group_number); |
| 133 | return 0; |
| 134 | } |
| 135 | printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[i].base_address); |
| 136 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | raw_pci_ops = &pci_mmcfg; |
| 139 | pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; |
| 140 | |
| 141 | return 0; |
| 142 | } |
| 143 | |
| 144 | arch_initcall(pci_mmcfg_init); |