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