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 #include "intel-iommu.h"
  30
  31 #undef PREFIX
  32 #define PREFIX "DMAR:"
  33
  34 /* No locks are needed as DMA remapping hardware unit
  35  * list is constructed at boot time and hotplug of
  36  * these units are not supported by the architecture.
  37  */
  38 LIST_HEAD(dmar_drhd_units);
  39 LIST_HEAD(dmar_rmrr_units);
  40
  41 static struct acpi_table_header * __initdata dmar_tbl;
  42
  43 static void __init dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
  44 {
  45         /*
  46          * add INCLUDE_ALL at the tail, so scan the list will find it at
  47          * the very end.
  48          */
  49         if (drhd->include_all)
  50                 list_add_tail(&drhd->list, &dmar_drhd_units);
  51         else
  52                 list_add(&drhd->list, &dmar_drhd_units);
  53 }
  54
  55 static void __init dmar_register_rmrr_unit(struct dmar_rmrr_unit *rmrr)
  56 {
  57         list_add(&rmrr->list, &dmar_rmrr_units);
  58 }
  59
  60 static int __init dmar_parse_one_dev_scope(struct acpi_dmar_device_scope *scope,
  61                                            struct pci_dev **dev, u16 segment)
  62 {
  63         struct pci_bus *bus;
  64         struct pci_dev *pdev = NULL;
  65         struct acpi_dmar_pci_path *path;
  66         int count;
  67
  68         bus = pci_find_bus(segment, scope->bus);
  69         path = (struct acpi_dmar_pci_path *)(scope + 1);
  70         count = (scope->length - sizeof(struct acpi_dmar_device_scope))
  71                 / sizeof(struct acpi_dmar_pci_path);
  72
  73         while (count) {
  74                 if (pdev)
  75                         pci_dev_put(pdev);
  76                 /*
  77                  * Some BIOSes list non-exist devices in DMAR table, just
  78                  * ignore it
  79                  */
  80                 if (!bus) {
  81                         printk(KERN_WARNING
  82                         PREFIX "Device scope bus [%d] not found\n",
  83                         scope->bus);
  84                         break;
  85                 }
  86                 pdev = pci_get_slot(bus, PCI_DEVFN(path->dev, path->fn));
  87                 if (!pdev) {
  88                         printk(KERN_WARNING PREFIX
  89                         "Device scope device [%04x:%02x:%02x.%02x] not found\n",
  90                                 segment, bus->number, path->dev, path->fn);
  91                         break;
  92                 }
  93                 path ++;
  94                 count --;
  95                 bus = pdev->subordinate;
  96         }
  97         if (!pdev) {
  98                 printk(KERN_WARNING PREFIX
  99                 "Device scope device [%04x:%02x:%02x.%02x] not found\n",
 100                 segment, scope->bus, path->dev, path->fn);
 101                 *dev = NULL;
 102                 return 0;
 103         }
 104         if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT && \
 105                         pdev->subordinate) || (scope->entry_type == \
 106                         ACPI_DMAR_SCOPE_TYPE_BRIDGE && !pdev->subordinate)) {
 107                 pci_dev_put(pdev);
 108                 printk(KERN_WARNING PREFIX
 109                         "Device scope type does not match for %s\n",
 110                          pci_name(pdev));
 111                 return -EINVAL;
 112         }
 113         *dev = pdev;
 114         return 0;
 115 }
 116
 117 static int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
 118                                        struct pci_dev ***devices, u16 segment)
 119 {
 120         struct acpi_dmar_device_scope *scope;
 121         void * tmp = start;
 122         int index;
 123         int ret;
 124
 125         *cnt = 0;
 126         while (start < end) {
 127                 scope = start;
 128                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 129                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
 130                         (*cnt)++;
 131                 else
 132                         printk(KERN_WARNING PREFIX
 133                                 "Unsupported device scope\n");
 134                 start += scope->length;
 135         }
 136         if (*cnt == 0)
 137                 return 0;
 138
 139         *devices = kcalloc(*cnt, sizeof(struct pci_dev *), GFP_KERNEL);
 140         if (!*devices)
 141                 return -ENOMEM;
 142
 143         start = tmp;
 144         index = 0;
 145         while (start < end) {
 146                 scope = start;
 147                 if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
 148                     scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE) {
 149                         ret = dmar_parse_one_dev_scope(scope,
 150                                 &(*devices)[index], segment);
 151                         if (ret) {
 152                                 kfree(*devices);
 153                                 return ret;
 154                         }
 155                         index ++;
 156                 }
 157                 start += scope->length;
 158         }
 159
 160         return 0;
 161 }
 162
 163 /**
 164  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
 165  * structure which uniquely represent one DMA remapping hardware unit
 166  * present in the platform
 167  */
 168 static int __init
 169 dmar_parse_one_drhd(struct acpi_dmar_header *header)
 170 {
 171         struct acpi_dmar_hardware_unit *drhd;
 172         struct dmar_drhd_unit *dmaru;
 173         int ret = 0;
 174         static int include_all;
 175
 176         dmaru = kzalloc(sizeof(*dmaru), GFP_KERNEL);
 177         if (!dmaru)
 178                 return -ENOMEM;
 179
 180         drhd = (struct acpi_dmar_hardware_unit *)header;
 181         dmaru->reg_base_addr = drhd->address;
 182         dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
 183
 184         if (!dmaru->include_all)
 185                 ret = dmar_parse_dev_scope((void *)(drhd + 1),
 186                                 ((void *)drhd) + header->length,
 187                                 &dmaru->devices_cnt, &dmaru->devices,
 188                                 drhd->segment);
 189         else {
 190                 /* Only allow one INCLUDE_ALL */
 191                 if (include_all) {
 192                         printk(KERN_WARNING PREFIX "Only one INCLUDE_ALL "
 193                                 "device scope is allowed\n");
 194                         ret = -EINVAL;
 195                 }
 196                 include_all = 1;
 197         }
 198
 199         if (ret || (dmaru->devices_cnt == 0 && !dmaru->include_all))
 200                 kfree(dmaru);
 201         else
 202                 dmar_register_drhd_unit(dmaru);
 203         return ret;
 204 }
 205
 206 static int __init
 207 dmar_parse_one_rmrr(struct acpi_dmar_header *header)
 208 {
 209         struct acpi_dmar_reserved_memory *rmrr;
 210         struct dmar_rmrr_unit *rmrru;
 211         int ret = 0;
 212
 213         rmrru = kzalloc(sizeof(*rmrru), GFP_KERNEL);
 214         if (!rmrru)
 215                 return -ENOMEM;
 216
 217         rmrr = (struct acpi_dmar_reserved_memory *)header;
 218         rmrru->base_address = rmrr->base_address;
 219         rmrru->end_address = rmrr->end_address;
 220         ret = dmar_parse_dev_scope((void *)(rmrr + 1),
 221                 ((void *)rmrr) + header->length,
 222                 &rmrru->devices_cnt, &rmrru->devices, rmrr->segment);
 223
 224         if (ret || (rmrru->devices_cnt == 0))
 225                 kfree(rmrru);
 226         else
 227                 dmar_register_rmrr_unit(rmrru);
 228         return ret;
 229 }
 230
 231 static void __init
 232 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
 233 {
 234         struct acpi_dmar_hardware_unit *drhd;
 235         struct acpi_dmar_reserved_memory *rmrr;
 236
 237         switch (header->type) {
 238         case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 239                 drhd = (struct acpi_dmar_hardware_unit *)header;
 240                 printk (KERN_INFO PREFIX
 241                         "DRHD (flags: 0x%08x)base: 0x%016Lx\n",
 242                         drhd->flags, drhd->address);
 243                 break;
 244         case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 245                 rmrr = (struct acpi_dmar_reserved_memory *)header;
 246
 247                 printk (KERN_INFO PREFIX
 248                         "RMRR base: 0x%016Lx end: 0x%016Lx\n",
 249                         rmrr->base_address, rmrr->end_address);
 250                 break;
 251         }
 252 }
 253
 254 /**
 255  * parse_dmar_table - parses the DMA reporting table
 256  */
 257 static int __init
 258 parse_dmar_table(void)
 259 {
 260         struct acpi_table_dmar *dmar;
 261         struct acpi_dmar_header *entry_header;
 262         int ret = 0;
 263
 264         dmar = (struct acpi_table_dmar *)dmar_tbl;
 265         if (!dmar)
 266                 return -ENODEV;
 267
 268         if (dmar->width < PAGE_SHIFT_4K - 1) {
 269                 printk(KERN_WARNING PREFIX "Invalid DMAR haw\n");
 270                 return -EINVAL;
 271         }
 272
 273         printk (KERN_INFO PREFIX "Host address width %d\n",
 274                 dmar->width + 1);
 275
 276         entry_header = (struct acpi_dmar_header *)(dmar + 1);
 277         while (((unsigned long)entry_header) <
 278                         (((unsigned long)dmar) + dmar_tbl->length)) {
 279                 dmar_table_print_dmar_entry(entry_header);
 280
 281                 switch (entry_header->type) {
 282                 case ACPI_DMAR_TYPE_HARDWARE_UNIT:
 283                         ret = dmar_parse_one_drhd(entry_header);
 284                         break;
 285                 case ACPI_DMAR_TYPE_RESERVED_MEMORY:
 286                         ret = dmar_parse_one_rmrr(entry_header);
 287                         break;
 288                 default:
 289                         printk(KERN_WARNING PREFIX
 290                                 "Unknown DMAR structure type\n");
 291                         ret = 0; /* for forward compatibility */
 292                         break;
 293                 }
 294                 if (ret)
 295                         break;
 296
 297                 entry_header = ((void *)entry_header + entry_header->length);
 298         }
 299         return ret;
 300 }
 301
 302
 303 int __init dmar_table_init(void)
 304 {
 305
 306         int ret;
 307
 308         ret = parse_dmar_table();
 309         if (ret) {
 310                 printk(KERN_INFO PREFIX "parse DMAR table failure.\n");
 311                 return ret;
 312         }
 313
 314         if (list_empty(&dmar_drhd_units)) {
 315                 printk(KERN_INFO PREFIX "No DMAR devices found\n");
 316                 return -ENODEV;
 317         }
 318
 319         if (list_empty(&dmar_rmrr_units)) {
 320                 printk(KERN_INFO PREFIX "No RMRR found\n");
 321                 return -ENODEV;
 322         }
 323
 324         return 0;
 325 }
 326
 327 /**
 328  * early_dmar_detect - checks to see if the platform supports DMAR devices
 329  */
 330 int __init early_dmar_detect(void)
 331 {
 332         acpi_status status = AE_OK;
 333
 334         /* if we could find DMAR table, then there are DMAR devices */
 335         status = acpi_get_table(ACPI_SIG_DMAR, 0,
 336                                 (struct acpi_table_header **)&dmar_tbl);
 337
 338         if (ACPI_SUCCESS(status) && !dmar_tbl) {
 339                 printk (KERN_WARNING PREFIX "Unable to map DMAR\n");
 340                 status = AE_NOT_FOUND;
 341         }
 342
 343         return (ACPI_SUCCESS(status) ? 1 : 0);
 344 }