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) 2006-2008 Intel Corporation
  18  * Author: Ashok Raj <ashok.raj@intel.com>
  19  * Author: Shaohua Li <shaohua.li@intel.com>
  20  * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  21  *
  22  * This file implements early detection/parsing of DMA Remapping Devices
  23  * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
  24  * tables.
  25  */
  26
  27 #include <linux/pci.h>
  28 #include <linux/dmar.h>
  29 #include "iova.h"
  30 #include "intel-iommu.h"
  31
  32 #undef PREFIX
  33 #define PREFIX "DMAR:"
  34
  35 /* No locks are needed as DMA remapping hardware unit
  36  * list is constructed at boot time and hotplug of
  37  * these units are not supported by the architecture.
  38  */
  39 LIST_HEAD(dmar_drhd_units);
  40 LIST_HEAD(dmar_rmrr_units);
  41
  42 static struct acpi_table_header * __initdata dmar_tbl;
  43
  44 static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
  45 {
  46         /*
  47          * add INCLUDE_ALL at the tail, so scan the list will find it at
  48          * the very end.
  49          */
  50         if (drhd->include_all)
  51                 list_add_tail(&drhd->list, &dmar_drhd_units);
  52         else
  53                 list_add(&drhd->list, &dmar_drhd_units);
  54 }
  55
  56 static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
  57 {
  58         list_add(&rmrr->list, &dmar_rmrr_units);
  59 }
  60
  61 static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
  62                                            struct pci_dev **dev, u16 segment)
  63 {
  64         struct pci_bus *bus;
  65         struct pci_dev *pdev = NULL;
  66         struct acpi_dmar_pci_path *path;
  67         int count;
  68
  69         bus = pci_find_bus(segment, scope->bus);
  70         path = (struct acpi_dmar_pci_path *)(scope + 1);
  71         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
  72                 / sizeof(struct acpi_dmar_pci_path);
  73
  74         while (count) {
  75                 if (pdev)
  76                         pci_dev_put(pdev);
  77                 /*
  78                  * Some BIOSes list non-exist devices in DMAR table, just
  79                  * ignore it
  80                  */
  81                 if (!bus) {
  82                         printk(KERN_WARNING
  83                         PREFIX "Device scope bus [%d] not found\n",
  84                         scope->bus);
  85                         break;
  86                 }
  87                 pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
  88                 if (!pdev) {
  89                         printk(KERN_WARNING PREFIX
  90                         "Device scope device [%04x:%02x:%02x.%02x] not found\n",
  91                                 segment, bus->number, path->dev, path->fn);
  92                         break;
  93                 }
  94                 path ++;
  95                 count --;
  96                 bus = pdev->subordinate;
  97         }
  98         if (!pdev) {
  99                 printk(KERN_WARNING PREFIX
 100                 "Device scope device [%04x:%02x:%02x.%02x] not found\n",
 101                 segment, scope->bus, path->dev, path->fn);
 102                 *dev = NULL;
 103                 return 0;
 104         }
 105         if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
 106                         pdev->subordinate) || (scope->entry_type == \
 107                         ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
 108                 pci_dev_put(pdev);
 109                 printk(KERN_WARNING PREFIX
 110                         "Device scope type does not match for %s\n",
 111                          pci_name(pdev));
 112                 return -EINVAL;
 113         }
 114         *dev = pdev;
 115         return 0;
 116 }
 117
 118 static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
 119                                        struct pci_dev ***devices, u16 segment)
 120 {
 121         struct acpi_dmar_device_scope *scope;
 122         void * tmp = start;
 123         int index;
 124         int ret;
 125
 126         *cnt = 0;
 127         while (start < end) {
 128                 scope = start;
 129                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 130                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 131                         (*cnt)++;
 132                 else
 133                         printk(KERN_WARNING PREFIX
 134                                 "Unsupported device scope\n");
 135                 start += scope->length;
 136         }
 137         if (*cnt == 0)
 138                 return 0;
 139
 140         *devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
 141         if (!*devices)
 142                 return -ENOMEM;
 143
 144         start = tmp;
 145         index = 0;
 146         while (start < end) {
 147                 scope = start;
 148                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 149                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
 150                         ret = dmar_parse_one_dev_scope(scope,
 151                                 &(*devices)[index], segment);
 152                         if (ret) {
 153                                 kfree(*devices);
 154                                 return ret;
 155                         }
 156                         index ++;
 157                 }
 158                 start += scope->length;
 159         }
 160
 161         return 0;
 162 }
 163
 164 /**
 165  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 166  * structure which uniquely represent one DMA remapping hardware unit
 167  * present in the platform
 168  */
 169 static int __init
 170 dmar_parse_one_drhd(struct acpi_dmar_header *header)
 171 {
 172         struct acpi_dmar_hardware_unit *drhd;
 173         struct dmar_drhd_unit *dmaru;
 174         int ret = 0;
 175         static int include_all;
 176
 177         dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
 178         if (!dmaru)
 179                 return -ENOMEM;
 180
 181         drhd = (struct acpi_dmar_hardware_unit *)header;
 182         dmaru->reg_base_addr = drhd->address;
 183         dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
 184
 185         if (!dmaru->include_all)
 186                 ret = dmar_parse_dev_scope((void *)(drhd + 1),
 187                                 ((void *)drhd) + header->length,
 188                                 &dmaru->devices_cnt, &dmaru->devices,
 189                                 drhd->segment);
 190         else {
 191                 /* Only allow one INCLUDE_ALL */
 192                 if (include_all) {
 193                         printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
 194                                 "device scope is allowed\n");
 195                         ret = -EINVAL;
 196                 }
 197                 include_all = 1;
 198         }
 199
 200         if (ret || (dmaru->devices_cnt == 0 && !dmaru->include_all))
 201                 kfree(dmaru);
 202         else
 203                 dmar_register_drhd_unit(dmaru);
 204         return ret;
 205 }
 206
 207 static int __init
 208 dmar_parse_one_rmrr(struct acpi_dmar_header *header)
 209 {
 210         struct acpi_dmar_reserved_memory *rmrr;
 211         struct dmar_rmrr_unit *rmrru;
 212         int ret = 0;
 213
 214         rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
 215         if (!rmrru)
 216                 return -ENOMEM;
 217
 218         rmrr = (struct acpi_dmar_reserved_memory *)header;
 219         rmrru->base_address = rmrr->base_address;
 220         rmrru->end_address = rmrr->end_address;
 221         ret = dmar_parse_dev_scope((void *)(rmrr + 1),
 222                 ((void *)rmrr) + header->length,
 223                 &rmrru->devices_cnt, &rmrru->devices, rmrr->segment);
 224
 225         if (ret || (rmrru->devices_cnt == 0))
 226                 kfree(rmrru);
 227         else
 228                 dmar_register_rmrr_unit(rmrru);
 229         return ret;
 230 }
 231
 232 static void __init
 233 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 234 {
 235         struct acpi_dmar_hardware_unit *drhd;
 236         struct acpi_dmar_reserved_memory *rmrr;
 237
 238         switch (header->type) {
 239         case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 240                 drhd = (struct acpi_dmar_hardware_unit *)header;
 241                 printk (KERN_INFO PREFIX
 242                         "DRHD (flags: 0x%08x)base: 0x%016Lx\n",
 243                         drhd->flags, drhd->address);
 244                 break;
 245         case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 246                 rmrr = (struct acpi_dmar_reserved_memory *)header;
 247
 248                 printk (KERN_INFO PREFIX
 249                         "RMRR base: 0x%016Lx end: 0x%016Lx\n",
 250                         rmrr->base_address, rmrr->end_address);
 251                 break;
 252         }
 253 }
 254
 255 /**
 256  * parse_dmar_table - parses the DMA reporting table
 257  */
 258 static int __init
 259 parse_dmar_table(void)
 260 {
 261         struct acpi_table_dmar *dmar;
 262         struct acpi_dmar_header *entry_header;
 263         int ret = 0;
 264
 265         dmar = (struct acpi_table_dmar *)dmar_tbl;
 266         if (!dmar)
 267                 return -ENODEV;
 268
 269         if (dmar->width < PAGE_SHIFT_4K - 1) {
 270                 printk(KERN_WARNING PREFIX "Invalid DMAR haw\n");
 271                 return -EINVAL;
 272         }
 273
 274         printk (KERN_INFO PREFIX "Host address width %d\n",
 275                 dmar->width + 1);
 276
 277         entry_header = (struct acpi_dmar_header *)(dmar + 1);
 278         while (((unsigned long)entry_header) <
 279                         (((unsigned long)dmar) + dmar_tbl->length)) {
 280                 dmar_table_print_dmar_entry(entry_header);
 281
 282                 switch (entry_header->type) {
 283                 case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 284                         ret = dmar_parse_one_drhd(entry_header);
 285                         break;
 286                 case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 287                         ret = dmar_parse_one_rmrr(entry_header);
 288                         break;
 289                 default:
 290                         printk(KERN_WARNING PREFIX
 291                                 "Unknown DMAR structure type\n");
 292                         ret = 0; /* for forward compatibility */
 293                         break;
 294                 }
 295                 if (ret)
 296                         break;
 297
 298                 entry_header = ((void *)entry_header + entry_header->length);
 299         }
 300         return ret;
 301 }
 302
 303
 304 int __init dmar_table_init(void)
 305 {
 306
 307         int ret;
 308
 309         ret = parse_dmar_table();
 310         if (ret) {
 311                 printk(KERN_INFO PREFIX "parse DMAR table failure.\n");
 312                 return ret;
 313         }
 314
 315         if (list_empty(&dmar_drhd_units)) {
 316                 printk(KERN_INFO PREFIX "No DMAR devices found\n");
 317                 return -ENODEV;
 318         }
 319
 320         if (list_empty(&dmar_rmrr_units))
 321                 printk(KERN_INFO PREFIX "No RMRR found\n");
 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 }