drivers/pci/dmar.c

   1 /*
   2  * Copyright (c) 2006, Intel Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  *      Copyright (C) Ashok Raj <ashok.raj@intel.com>
  18  *      Copyright (C) Shaohua Li <shaohua.li@intel.com>
  19  *      Copyright (C) Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  20  *
  21  *      This file implements early detection/parsing of DMA Remapping Devices
  22  * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
  23  * tables.
  24  */
  25
  26 #include <linux/pci.h>
  27 #include <linux/dmar.h>
  28 #include "iova.h"
  29
  30 #undef PREFIX
  31 #define PREFIX "DMAR:"
  32
  33 /* No locks are needed as DMA remapping hardware unit
  34  * list is constructed at boot time and hotplug of
  35  * these units are not supported by the architecture.
  36  */
  37 LIST_HEAD(dmar_drhd_units);
  38 LIST_HEAD(dmar_rmrr_units);
  39
  40 static struct acpi_table_header * __initdata dmar_tbl;
  41
  42 static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
  43 {
  44         /*
  45          * add INCLUDE_ALL at the tail, so scan the list will find it at
  46          * the very end.
  47          */
  48         if (drhd->include_all)
  49                 list_add_tail(&drhd->list, &dmar_drhd_units);
  50         else
  51                 list_add(&drhd->list, &dmar_drhd_units);
  52 }
  53
  54 static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
  55 {
  56         list_add(&rmrr->list, &dmar_rmrr_units);
  57 }
  58
  59 static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
  60                                            struct pci_dev **dev, u16 segment)
  61 {
  62         struct pci_bus *bus;
  63         struct pci_dev *pdev = NULL;
  64         struct acpi_dmar_pci_path *path;
  65         int count;
  66
  67         bus = pci_find_bus(segment, scope->bus);
  68         path = (struct acpi_dmar_pci_path *)(scope + 1);
  69         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
  70                 / sizeof(struct acpi_dmar_pci_path);
  71
  72         while (count) {
  73                 if (pdev)
  74                         pci_dev_put(pdev);
  75                 /*
  76                  * Some BIOSes list non-exist devices in DMAR table, just
  77                  * ignore it
  78                  */
  79                 if (!bus) {
  80                         printk(KERN_WARNING
  81                         PREFIX "Device scope bus [%d] not found\n",
  82                         scope->bus);
  83                         break;
  84                 }
  85                 pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
  86                 if (!pdev) {
  87                         printk(KERN_WARNING PREFIX
  88                         "Device scope device [%04x:%02x:%02x.%02x] not found\n",
  89                                 segment, bus->number, path->dev, path->fn);
  90                         break;
  91                 }
  92                 path ++;
  93                 count --;
  94                 bus = pdev->subordinate;
  95         }
  96         if (!pdev) {
  97                 printk(KERN_WARNING PREFIX
  98                 "Device scope device [%04x:%02x:%02x.%02x] not found\n",
  99                 segment, scope->bus, path->dev, path->fn);
 100                 *dev = NULL;
 101                 return 0;
 102         }
 103         if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
 104                         pdev->subordinate) || (scope->entry_type == \
 105                         ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
 106                 pci_dev_put(pdev);
 107                 printk(KERN_WARNING PREFIX
 108                         "Device scope type does not match for %s\n",
 109                          pci_name(pdev));
 110                 return -EINVAL;
 111         }
 112         *dev = pdev;
 113         return 0;
 114 }
 115
 116 static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
 117                                        struct pci_dev ***devices, u16 segment)
 118 {
 119         struct acpi_dmar_device_scope *scope;
 120         void * tmp = start;
 121         int index;
 122         int ret;
 123
 124         *cnt = 0;
 125         while (start < end) {
 126                 scope = start;
 127                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 128                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 129                         (*cnt)++;
 130                 else
 131                         printk(KERN_WARNING PREFIX
 132                                 "Unsupported device scope\n");
 133                 start += scope->length;
 134         }
 135         if (*cnt == 0)
 136                 return 0;
 137
 138         *devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
 139         if (!*devices)
 140                 return -ENOMEM;
 141
 142         start = tmp;
 143         index = 0;
 144         while (start < end) {
 145                 scope = start;
 146                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 147                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
 148                         ret = dmar_parse_one_dev_scope(scope,
 149                                 &(*devices)[index], segment);
 150                         if (ret) {
 151                                 kfree(*devices);
 152                                 return ret;
 153                         }
 154                         index ++;
 155                 }
 156                 start += scope->length;
 157         }
 158
 159         return 0;
 160 }
 161
 162 /**
 163  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 164  * structure which uniquely represent one DMA remapping hardware unit
 165  * present in the platform
 166  */
 167 static int __init
 168 dmar_parse_one_drhd(struct acpi_dmar_header *header)
 169 {
 170         struct acpi_dmar_hardware_unit *drhd;
 171         struct dmar_drhd_unit *dmaru;
 172         int ret = 0;
 173         static int include_all;
 174
 175         dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
 176         if (!dmaru)
 177                 return -ENOMEM;
 178
 179         drhd = (struct acpi_dmar_hardware_unit *)header;
 180         dmaru->reg_base_addr = drhd->address;
 181         dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
 182
 183         if (!dmaru->include_all)
 184                 ret = dmar_parse_dev_scope((void *)(drhd + 1),
 185                                 ((void *)drhd) + header->length,
 186                                 &dmaru->devices_cnt, &dmaru->devices,
 187                                 drhd->segment);
 188         else {
 189                 /* Only allow one INCLUDE_ALL */
 190                 if (include_all) {
 191                         printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
 192                                 "device scope is allowed\n");
 193                         ret = -EINVAL;
 194                 }
 195                 include_all = 1;
 196         }
 197
 198         if (ret || (dmaru->devices_cnt == 0 && !dmaru->include_all))
 199                 kfree(dmaru);
 200         else
 201                 dmar_register_drhd_unit(dmaru);
 202         return ret;
 203 }
 204
 205 static int __init
 206 dmar_parse_one_rmrr(struct acpi_dmar_header *header)
 207 {
 208         struct acpi_dmar_reserved_memory *rmrr;
 209         struct dmar_rmrr_unit *rmrru;
 210         int ret = 0;
 211
 212         rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
 213         if (!rmrru)
 214                 return -ENOMEM;
 215
 216         rmrr = (struct acpi_dmar_reserved_memory *)header;
 217         rmrru->base_address = rmrr->base_address;
 218         rmrru->end_address = rmrr->end_address;
 219         ret = dmar_parse_dev_scope((void *)(rmrr + 1),
 220                 ((void *)rmrr) + header->length,
 221                 &rmrru->devices_cnt, &rmrru->devices, rmrr->segment);
 222
 223         if (ret || (rmrru->devices_cnt == 0))
 224                 kfree(rmrru);
 225         else
 226                 dmar_register_rmrr_unit(rmrru);
 227         return ret;
 228 }
 229
 230 static void __init
 231 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 232 {
 233         struct acpi_dmar_hardware_unit *drhd;
 234         struct acpi_dmar_reserved_memory *rmrr;
 235
 236         switch (header->type) {
 237         case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 238                 drhd = (struct acpi_dmar_hardware_unit *)header;
 239                 printk (KERN_INFO PREFIX
 240                         "DRHD (flags: 0x%08x)base: 0x%016Lx\n",
 241                         drhd->flags, drhd->address);
 242                 break;
 243         case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 244                 rmrr = (struct acpi_dmar_reserved_memory *)header;
 245
 246                 printk (KERN_INFO PREFIX
 247                         "RMRR base: 0x%016Lx end: 0x%016Lx\n",
 248                         rmrr->base_address, rmrr->end_address);
 249                 break;
 250         }
 251 }
 252
 253 /**
 254  * parse_dmar_table - parses the DMA reporting table
 255  */
 256 static int __init
 257 parse_dmar_table(void)
 258 {
 259         struct acpi_table_dmar *dmar;
 260         struct acpi_dmar_header *entry_header;
 261         int ret = 0;
 262
 263         dmar = (struct acpi_table_dmar *)dmar_tbl;
 264         if (!dmar)
 265                 return -ENODEV;
 266
 267         if (dmar->width < PAGE_SHIFT_4K - 1) {
 268                 printk(KERN_WARNING PREFIX "Invalid DMAR haw\n");
 269                 return -EINVAL;
 270         }
 271
 272         printk (KERN_INFO PREFIX "Host address width %d\n",
 273                 dmar->width + 1);
 274
 275         entry_header = (struct acpi_dmar_header *)(dmar + 1);
 276         while (((unsigned long)entry_header) <
 277                         (((unsigned long)dmar) + dmar_tbl->length)) {
 278                 dmar_table_print_dmar_entry(entry_header);
 279
 280                 switch (entry_header->type) {
 281                 case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 282                         ret = dmar_parse_one_drhd(entry_header);
 283                         break;
 284                 case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 285                         ret = dmar_parse_one_rmrr(entry_header);
 286                         break;
 287                 default:
 288                         printk(KERN_WARNING PREFIX
 289                                 "Unknown DMAR structure type\n");
 290                         ret = 0; /* for forward compatibility */
 291                         break;
 292                 }
 293                 if (ret)
 294                         break;
 295
 296                 entry_header = ((void *)entry_header + entry_header->length);
 297         }
 298         return ret;
 299 }
 300
 301
 302 int __init dmar_table_init(void)
 303 {
 304
 305         int ret;
 306
 307         ret = parse_dmar_table();
 308         if (ret) {
 309                 printk(KERN_INFO PREFIX "parse DMAR table failure.\n");
 310                 return ret;
 311         }
 312
 313         if (list_empty(&dmar_drhd_units)) {
 314                 printk(KERN_INFO PREFIX "No DMAR devices found\n");
 315                 return -ENODEV;
 316         }
 317
 318         if (list_empty(&dmar_rmrr_units)) {
 319                 printk(KERN_INFO PREFIX "No RMRR found\n");
 320                 return -ENODEV;
 321         }
 322
 323         return 0;
 324 }
 325
 326 /**
 327  * early_dmar_detect - checks to see if the platform supports DMAR devices
 328  */
 329 int __init early_dmar_detect(void)
 330 {
 331         acpi_status status = AE_OK;
 332
 333         /* if we could find DMAR table, then there are DMAR devices */
 334         status = acpi_get_table(ACPI_SIG_DMAR, 0,
 335                                 (struct acpi_table_header **)&dmar_tbl);
 336
 337         if (ACPI_SUCCESS(status) && !dmar_tbl) {
 338                 printk (KERN_WARNING PREFIX "Unable to map DMAR\n");
 339                 status = AE_NOT_FOUND;
 340         }
 341
 342         return (ACPI_SUCCESS(status) ? 1 : 0);
 343 }