arch/x86/pci/mmconfig-shared.c

   1 /*
   2  * mmconfig-shared.c - Low-level direct PCI config space access via
   3  *                     MMCONFIG - common code between i386 and x86-64.
   4  *
   5  * This code does:
   6  * - known chipset handling
   7  * - ACPI decoding and validation
   8  *
   9  * Per-architecture code takes care of the mappings and accesses
  10  * themselves.
  11  */
  12
  13 #include <linux/pci.h>
  14 #include <linux/init.h>
  15 #include <linux/acpi.h>
  16 #include <linux/bitmap.h>
  17 #include <asm/e820.h>
  18
  19 #include "pci.h"
  20
  21 /* aperture is up to 256MB but BIOS may reserve less */
  22 #define MMCONFIG_APER_MIN       (2 * 1024*1024)
  23 #define MMCONFIG_APER_MAX       (256 * 1024*1024)
  24
  25 /* Indicate if the mmcfg resources have been placed into the resource table. */
  26 static int __initdata pci_mmcfg_resources_inserted;
  27
  28 static const char __init *pci_mmcfg_e7520(void)
  29 {
  30         u32 win;
  31         pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0xce, 2, &win);
  32
  33         win = win & 0xf000;
  34         if(win == 0x0000 || win == 0xf000)
  35                 pci_mmcfg_config_num = 0;
  36         else {
  37                 pci_mmcfg_config_num = 1;
  38                 pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
  39                 if (!pci_mmcfg_config)
  40                         return NULL;
  41                 pci_mmcfg_config[0].address = win << 16;
  42                 pci_mmcfg_config[0].pci_segment = 0;
  43                 pci_mmcfg_config[0].start_bus_number = 0;
  44                 pci_mmcfg_config[0].end_bus_number = 255;
  45         }
  46
  47         return "Intel Corporation E7520 Memory Controller Hub";
  48 }
  49
  50 static const char __init *pci_mmcfg_intel_945(void)
  51 {
  52         u32 pciexbar, mask = 0, len = 0;
  53
  54         pci_mmcfg_config_num = 1;
  55
  56         pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0x48, 4, &pciexbar);
  57
  58         /* Enable bit */
  59         if (!(pciexbar & 1))
  60                 pci_mmcfg_config_num = 0;
  61
  62         /* Size bits */
  63         switch ((pciexbar >> 1) & 3) {
  64         case 0:
  65                 mask = 0xf0000000U;
  66                 len  = 0x10000000U;
  67                 break;
  68         case 1:
  69                 mask = 0xf8000000U;
  70                 len  = 0x08000000U;
  71                 break;
  72         case 2:
  73                 mask = 0xfc000000U;
  74                 len  = 0x04000000U;
  75                 break;
  76         default:
  77                 pci_mmcfg_config_num = 0;
  78         }
  79
  80         /* Errata #2, things break when not aligned on a 256Mb boundary */
  81         /* Can only happen in 64M/128M mode */
  82
  83         if ((pciexbar & mask) & 0x0fffffffU)
  84                 pci_mmcfg_config_num = 0;
  85
  86         /* Don't hit the APIC registers and their friends */
  87         if ((pciexbar & mask) >= 0xf0000000U)
  88                 pci_mmcfg_config_num = 0;
  89
  90         if (pci_mmcfg_config_num) {
  91                 pci_mmcfg_config = kzalloc(sizeof(pci_mmcfg_config[0]), GFP_KERNEL);
  92                 if (!pci_mmcfg_config)
  93                         return NULL;
  94                 pci_mmcfg_config[0].address = pciexbar & mask;
  95                 pci_mmcfg_config[0].pci_segment = 0;
  96                 pci_mmcfg_config[0].start_bus_number = 0;
  97                 pci_mmcfg_config[0].end_bus_number = (len >> 20) - 1;
  98         }
  99
 100         return "Intel Corporation 945G/GZ/P/PL Express Memory Controller Hub";
 101 }
 102
 103 struct pci_mmcfg_hostbridge_probe {
 104         u32 vendor;
 105         u32 device;
 106         const char *(*probe)(void);
 107 };
 108
 109 static struct pci_mmcfg_hostbridge_probe pci_mmcfg_probes[] __initdata = {
 110         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_E7520_MCH, pci_mmcfg_e7520 },
 111         { PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_INTEL_82945G_HB, pci_mmcfg_intel_945 },
 112 };
 113
 114 static int __init pci_mmcfg_check_hostbridge(void)
 115 {
 116         u32 l;
 117         u16 vendor, device;
 118         int i;
 119         const char *name;
 120
 121         pci_conf1_read(0, 0, PCI_DEVFN(0,0), 0, 4, &l);
 122         vendor = l & 0xffff;
 123         device = (l >> 16) & 0xffff;
 124
 125         pci_mmcfg_config_num = 0;
 126         pci_mmcfg_config = NULL;
 127         name = NULL;
 128
 129         for (i = 0; !name && i < ARRAY_SIZE(pci_mmcfg_probes); i++) {
 130                 if (pci_mmcfg_probes[i].vendor == vendor &&
 131                     pci_mmcfg_probes[i].device == device)
 132                         name = pci_mmcfg_probes[i].probe();
 133         }
 134
 135         if (name) {
 136                 printk(KERN_INFO "PCI: Found %s %s MMCONFIG support.\n",
 137                        name, pci_mmcfg_config_num ? "with" : "without");
 138         }
 139
 140         return name != NULL;
 141 }
 142
 143 static void __init pci_mmcfg_insert_resources(unsigned long resource_flags)
 144 {
 145 #define PCI_MMCFG_RESOURCE_NAME_LEN 19
 146         int i;
 147         struct resource *res;
 148         char *names;
 149         unsigned num_buses;
 150
 151         res = kcalloc(PCI_MMCFG_RESOURCE_NAME_LEN + sizeof(*res),
 152                         pci_mmcfg_config_num, GFP_KERNEL);
 153         if (!res) {
 154                 printk(KERN_ERR "PCI: Unable to allocate MMCONFIG resources\n");
 155                 return;
 156         }
 157
 158         names = (void *)&res[pci_mmcfg_config_num];
 159         for (i = 0; i < pci_mmcfg_config_num; i++, res++) {
 160                 struct acpi_mcfg_allocation *cfg = &pci_mmcfg_config[i];
 161                 num_buses = cfg->end_bus_number - cfg->start_bus_number + 1;
 162                 res->name = names;
 163                 snprintf(names, PCI_MMCFG_RESOURCE_NAME_LEN, "PCI MMCONFIG %u",
 164                          cfg->pci_segment);
 165                 res->start = cfg->address;
 166                 res->end = res->start + (num_buses << 20) - 1;
 167                 res->flags = IORESOURCE_MEM | resource_flags;
 168                 insert_resource(&iomem_resource, res);
 169                 names += PCI_MMCFG_RESOURCE_NAME_LEN;
 170         }
 171
 172         /* Mark that the resources have been inserted. */
 173         pci_mmcfg_resources_inserted = 1;
 174 }
 175
 176 static void __init pci_mmcfg_reject_broken(int type)
 177 {
 178         typeof(pci_mmcfg_config[0]) *cfg;
 179
 180         if ((pci_mmcfg_config_num == 0) ||
 181             (pci_mmcfg_config == NULL) ||
 182             (pci_mmcfg_config[0].address == 0))
 183                 return;
 184
 185         cfg = &pci_mmcfg_config[0];
 186
 187         /*
 188          * Handle more broken MCFG tables on Asus etc.
 189          * They only contain a single entry for bus 0-0.
 190          */
 191         if (pci_mmcfg_config_num == 1 &&
 192             cfg->pci_segment == 0 &&
 193             (cfg->start_bus_number | cfg->end_bus_number) == 0) {
 194                 printk(KERN_ERR "PCI: start and end of bus number is 0. "
 195                        "Rejected as broken MCFG.\n");
 196                 goto reject;
 197         }
 198
 199         /*
 200          * Only do this check when type 1 works. If it doesn't work
 201          * assume we run on a Mac and always use MCFG
 202          */
 203         if (type == 1 && !e820_all_mapped(cfg->address,
 204                                           cfg->address + MMCONFIG_APER_MIN,
 205                                           E820_RESERVED)) {
 206                 printk(KERN_ERR "PCI: BIOS Bug: MCFG area at %Lx is not"
 207                        " E820-reserved\n", cfg->address);
 208                 goto reject;
 209         }
 210         return;
 211
 212 reject:
 213         printk(KERN_ERR "PCI: Not using MMCONFIG.\n");
 214         kfree(pci_mmcfg_config);
 215         pci_mmcfg_config = NULL;
 216         pci_mmcfg_config_num = 0;
 217 }
 218
 219 void __init pci_mmcfg_init(int type)
 220 {
 221         int known_bridge = 0;
 222
 223         if ((pci_probe & PCI_PROBE_MMCONF) == 0)
 224                 return;
 225
 226         if (type == 1 && pci_mmcfg_check_hostbridge())
 227                 known_bridge = 1;
 228
 229         if (!known_bridge) {
 230                 acpi_table_parse(ACPI_SIG_MCFG, acpi_parse_mcfg);
 231                 pci_mmcfg_reject_broken(type);
 232         }
 233
 234         if ((pci_mmcfg_config_num == 0) ||
 235             (pci_mmcfg_config == NULL) ||
 236             (pci_mmcfg_config[0].address == 0))
 237                 return;
 238
 239         if (pci_mmcfg_arch_init()) {
 240                 if (known_bridge)
 241                         pci_mmcfg_insert_resources(IORESOURCE_BUSY);
 242                 pci_probe = (pci_probe & ~PCI_PROBE_MASK) | PCI_PROBE_MMCONF;
 243         } else {
 244                 /*
 245                  * Signal not to attempt to insert mmcfg resources because
 246                  * the architecture mmcfg setup could not initialize.
 247                  */
 248                 pci_mmcfg_resources_inserted = 1;
 249         }
 250 }
 251
 252 static int __init pci_mmcfg_late_insert_resources(void)
 253 {
 254         /*
 255          * If resources are already inserted or we are not using MMCONFIG,
 256          * don't insert the resources.
 257          */
 258         if ((pci_mmcfg_resources_inserted == 1) ||
 259             (pci_probe & PCI_PROBE_MMCONF) == 0 ||
 260             (pci_mmcfg_config_num == 0) ||
 261             (pci_mmcfg_config == NULL) ||
 262             (pci_mmcfg_config[0].address == 0))
 263                 return 1;
 264
 265         /*
 266          * Attempt to insert the mmcfg resources but not with the busy flag
 267          * marked so it won't cause request errors when __request_region is
 268          * called.
 269          */
 270         pci_mmcfg_insert_resources(0);
 271
 272         return 0;
 273 }
 274
 275 /*
 276  * Perform MMCONFIG resource insertion after PCI initialization to allow for
 277  * misprogrammed MCFG tables that state larger sizes but actually conflict
 278  * with other system resources.
 279  */
 280 late_initcall(pci_mmcfg_late_insert_resources);