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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 | /* * mmconfig.c - Low-level direct PCI config space access via MMCONFIG * * This is an 64bit optimized version that always keeps the full mmconfig * space mapped. This allows lockless config space operation. */ #include <linux/pci.h> #include <linux/init.h> #include <linux/acpi.h> #include <linux/bitmap.h> #include "pci.h" #define MMCONFIG_APER_SIZE (256*1024*1024) static DECLARE_BITMAP(fallback_slots, 32); /* Static virtual mapping of the MMCONFIG aperture */ struct mmcfg_virt { struct acpi_table_mcfg_config *cfg; char __iomem *virt; }; static struct mmcfg_virt *pci_mmcfg_virt; static char __iomem *get_virt(unsigned int seg, unsigned bus) { int cfg_num = -1; struct acpi_table_mcfg_config *cfg; while (1) { ++cfg_num; if (cfg_num >= pci_mmcfg_config_num) { /* Not found - fall back to type 1. This happens e.g. on the internal devices of a K8 northbridge. */ return NULL; } cfg = pci_mmcfg_virt[cfg_num].cfg; if (cfg->pci_segment_group_number != seg) continue; if ((cfg->start_bus_number <= bus) && (cfg->end_bus_number >= bus)) return pci_mmcfg_virt[cfg_num].virt; } } static char __iomem *pci_dev_base(unsigned int seg, unsigned int bus, unsigned int devfn) { char __iomem *addr; if (seg == 0 && bus == 0 && test_bit(PCI_SLOT(devfn), &fallback_slots)) return NULL; addr = get_virt(seg, bus); if (!addr) return NULL; return addr + ((bus << 20) | (devfn << 12)); } static int pci_mmcfg_read(unsigned int seg, unsigned int bus, unsigned int devfn, int reg, int len, u32 *value) { char __iomem *addr; /* Why do we have this when nobody checks it. How about a BUG()!? -AK */ if (unlikely(!value || (bus > 255) || (devfn > 255) || (reg > 4095))) return -EINVAL; addr = pci_dev_base(seg, bus, devfn); if (!addr) return pci_conf1_read(seg,bus,devfn,reg,len,value); switch (len) { case 1: *value = readb(addr + reg); break; case 2: *value = readw(addr + reg); break; case 4: *value = readl(addr + reg); break; } return 0; } static int pci_mmcfg_write(unsigned int seg, unsigned int bus, unsigned int devfn, int reg, int len, u32 value) { char __iomem *addr; /* Why do we have this when nobody checks it. How about a BUG()!? -AK */ if (unlikely((bus > 255) || (devfn > 255) || (reg > 4095))) return -EINVAL; addr = pci_dev_base(seg, bus, devfn); if (!addr) return pci_conf1_write(seg,bus,devfn,reg,len,value); switch (len) { case 1: writeb(value, addr + reg); break; case 2: writew(value, addr + reg); break; case 4: writel(value, addr + reg); break; } return 0; } static struct pci_raw_ops pci_mmcfg = { .read = pci_mmcfg_read, .write = pci_mmcfg_write, }; /* K8 systems have some devices (typically in the builtin northbridge) that are only accessible using type1 Normally this can be expressed in the MCFG by not listing them and assigning suitable _SEGs, but this isn't implemented in some BIOS. Instead try to discover all devices on bus 0 that are unreachable using MM and fallback for them. We only do this for bus 0/seg 0 */ static __init void unreachable_devices(void) { int i; for (i = 0; i < 32; i++) { u32 val1; char __iomem *addr; pci_conf1_read(0, 0, PCI_DEVFN(i,0), 0, 4, &val1); if (val1 == 0xffffffff) continue; addr = pci_dev_base(0, 0, PCI_DEVFN(i, 0)); if (addr == NULL|| readl(addr) != val1) { set_bit(i, &fallback_slots); } } } static int __init pci_mmcfg_init(void) { int i; if ((pci_probe & PCI_PROBE_MMCONF) == 0) return 0; acpi_table_parse(ACPI_MCFG, acpi_parse_mcfg); if ((pci_mmcfg_config_num == 0) || (pci_mmcfg_config == NULL) || (pci_mmcfg_config[0].base_address == 0)) return 0; /* RED-PEN i386 doesn't do _nocache right now */ pci_mmcfg_virt = kmalloc(sizeof(*pci_mmcfg_virt) * pci_mmcfg_config_num, GFP_KERNEL); if (pci_mmcfg_virt == NULL) { printk("PCI: Can not allocate memory for mmconfig structures\n"); return 0; } for (i = 0; i < pci_mmcfg_config_num; ++i) { pci_mmcfg_virt[i].cfg = &pci_mmcfg_config[i]; pci_mmcfg_virt[i].virt = ioremap_nocache(pci_mmcfg_config[i].base_address, MMCONFIG_APER_SIZE); if (!pci_mmcfg_virt[i].virt) { printk("PCI: Cannot map mmconfig aperture for segment %d\n", pci_mmcfg_config[i].pci_segment_group_number); return 0; } printk(KERN_INFO "PCI: Using MMCONFIG at %x\n", pci_mmcfg_config[i].base_address); } unreachable_devices(); raw_pci_ops = &pci_mmcfg; pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF; return 0; } arch_initcall(pci_mmcfg_init); |