drivers/xen/xen-pciback/conf_space_header.c

   1 /*
   2  * PCI Backend - Handles the virtual fields in the configuration space headers.
   3  *
   4  * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/pci.h>
   9 #include "pciback.h"
  10 #include "conf_space.h"
  11
  12 struct pci_bar_info {
  13         u32 val;
  14         u32 len_val;
  15         int which;
  16 };
  17
  18 #define DRV_NAME        "xen-pciback"
  19 #define is_enable_cmd(value) ((value)&(PCI_COMMAND_MEMORY|PCI_COMMAND_IO))
  20 #define is_master_cmd(value) ((value)&PCI_COMMAND_MASTER)
  21
  22 static int command_read(struct pci_dev *dev, int offset, u16 *value, void *data)
  23 {
  24         int i;
  25         int ret;
  26
  27         ret = xen_pcibk_read_config_word(dev, offset, value, data);
  28         if (!atomic_read(&dev->enable_cnt))
  29                 return ret;
  30
  31         for (i = 0; i < PCI_ROM_RESOURCE; i++) {
  32                 if (dev->resource[i].flags & IORESOURCE_IO)
  33                         *value |= PCI_COMMAND_IO;
  34                 if (dev->resource[i].flags & IORESOURCE_MEM)
  35                         *value |= PCI_COMMAND_MEMORY;
  36         }
  37
  38         return ret;
  39 }
  40
  41 static int command_write(struct pci_dev *dev, int offset, u16 value, void *data)
  42 {
  43         struct xen_pcibk_dev_data *dev_data;
  44         int err;
  45
  46         dev_data = pci_get_drvdata(dev);
  47         if (!pci_is_enabled(dev) && is_enable_cmd(value)) {
  48                 if (unlikely(verbose_request))
  49                         printk(KERN_DEBUG DRV_NAME ": %s: enable\n",
  50                                pci_name(dev));
  51                 err = pci_enable_device(dev);
  52                 if (err)
  53                         return err;
  54                 if (dev_data)
  55                         dev_data->enable_intx = 1;
  56         } else if (pci_is_enabled(dev) && !is_enable_cmd(value)) {
  57                 if (unlikely(verbose_request))
  58                         printk(KERN_DEBUG DRV_NAME ": %s: disable\n",
  59                                pci_name(dev));
  60                 pci_disable_device(dev);
  61                 if (dev_data)
  62                         dev_data->enable_intx = 0;
  63         }
  64
  65         if (!dev->is_busmaster && is_master_cmd(value)) {
  66                 if (unlikely(verbose_request))
  67                         printk(KERN_DEBUG DRV_NAME ": %s: set bus master\n",
  68                                pci_name(dev));
  69                 pci_set_master(dev);
  70         }
  71
  72         if (value & PCI_COMMAND_INVALIDATE) {
  73                 if (unlikely(verbose_request))
  74                         printk(KERN_DEBUG
  75                                DRV_NAME ": %s: enable memory-write-invalidate\n",
  76                                pci_name(dev));
  77                 err = pci_set_mwi(dev);
  78                 if (err) {
  79                         printk(KERN_WARNING
  80                                DRV_NAME ": %s: cannot enable "
  81                                "memory-write-invalidate (%d)\n",
  82                                pci_name(dev), err);
  83                         value &= ~PCI_COMMAND_INVALIDATE;
  84                 }
  85         }
  86
  87         return pci_write_config_word(dev, offset, value);
  88 }
  89
  90 static int rom_write(struct pci_dev *dev, int offset, u32 value, void *data)
  91 {
  92         struct pci_bar_info *bar = data;
  93
  94         if (unlikely(!bar)) {
  95                 printk(KERN_WARNING DRV_NAME ": driver data not found for %s\n",
  96                        pci_name(dev));
  97                 return XEN_PCI_ERR_op_failed;
  98         }
  99
 100         /* A write to obtain the length must happen as a 32-bit write.
 101          * This does not (yet) support writing individual bytes
 102          */
 103         if (value == ~PCI_ROM_ADDRESS_ENABLE)
 104                 bar->which = 1;
 105         else {
 106                 u32 tmpval;
 107                 pci_read_config_dword(dev, offset, &tmpval);
 108                 if (tmpval != bar->val && value == bar->val) {
 109                         /* Allow restoration of bar value. */
 110                         pci_write_config_dword(dev, offset, bar->val);
 111                 }
 112                 bar->which = 0;
 113         }
 114
 115         /* Do we need to support enabling/disabling the rom address here? */
 116
 117         return 0;
 118 }
 119
 120 /* For the BARs, only allow writes which write ~0 or
 121  * the correct resource information
 122  * (Needed for when the driver probes the resource usage)
 123  */
 124 static int bar_write(struct pci_dev *dev, int offset, u32 value, void *data)
 125 {
 126         struct pci_bar_info *bar = data;
 127
 128         if (unlikely(!bar)) {
 129                 printk(KERN_WARNING DRV_NAME ": driver data not found for %s\n",
 130                        pci_name(dev));
 131                 return XEN_PCI_ERR_op_failed;
 132         }
 133
 134         /* A write to obtain the length must happen as a 32-bit write.
 135          * This does not (yet) support writing individual bytes
 136          */
 137         if (value == ~0)
 138                 bar->which = 1;
 139         else {
 140                 u32 tmpval;
 141                 pci_read_config_dword(dev, offset, &tmpval);
 142                 if (tmpval != bar->val && value == bar->val) {
 143                         /* Allow restoration of bar value. */
 144                         pci_write_config_dword(dev, offset, bar->val);
 145                 }
 146                 bar->which = 0;
 147         }
 148
 149         return 0;
 150 }
 151
 152 static int bar_read(struct pci_dev *dev, int offset, u32 * value, void *data)
 153 {
 154         struct pci_bar_info *bar = data;
 155
 156         if (unlikely(!bar)) {
 157                 printk(KERN_WARNING DRV_NAME ": driver data not found for %s\n",
 158                        pci_name(dev));
 159                 return XEN_PCI_ERR_op_failed;
 160         }
 161
 162         *value = bar->which ? bar->len_val : bar->val;
 163
 164         return 0;
 165 }
 166
 167 static inline void read_dev_bar(struct pci_dev *dev,
 168                                 struct pci_bar_info *bar_info, int offset,
 169                                 u32 len_mask)
 170 {
 171         int     pos;
 172         struct resource *res = dev->resource;
 173
 174         if (offset == PCI_ROM_ADDRESS || offset == PCI_ROM_ADDRESS1)
 175                 pos = PCI_ROM_RESOURCE;
 176         else {
 177                 pos = (offset - PCI_BASE_ADDRESS_0) / 4;
 178                 if (pos && ((res[pos - 1].flags & (PCI_BASE_ADDRESS_SPACE |
 179                                 PCI_BASE_ADDRESS_MEM_TYPE_MASK)) ==
 180                            (PCI_BASE_ADDRESS_SPACE_MEMORY |
 181                                 PCI_BASE_ADDRESS_MEM_TYPE_64))) {
 182                         bar_info->val = res[pos - 1].start >> 32;
 183                         bar_info->len_val = res[pos - 1].end >> 32;
 184                         return;
 185                 }
 186         }
 187
 188         bar_info->val = res[pos].start |
 189                         (res[pos].flags & PCI_REGION_FLAG_MASK);
 190         bar_info->len_val = res[pos].end - res[pos].start + 1;
 191 }
 192
 193 static void *bar_init(struct pci_dev *dev, int offset)
 194 {
 195         struct pci_bar_info *bar = kmalloc(sizeof(*bar), GFP_KERNEL);
 196
 197         if (!bar)
 198                 return ERR_PTR(-ENOMEM);
 199
 200         read_dev_bar(dev, bar, offset, ~0);
 201         bar->which = 0;
 202
 203         return bar;
 204 }
 205
 206 static void *rom_init(struct pci_dev *dev, int offset)
 207 {
 208         struct pci_bar_info *bar = kmalloc(sizeof(*bar), GFP_KERNEL);
 209
 210         if (!bar)
 211                 return ERR_PTR(-ENOMEM);
 212
 213         read_dev_bar(dev, bar, offset, ~PCI_ROM_ADDRESS_ENABLE);
 214         bar->which = 0;
 215
 216         return bar;
 217 }
 218
 219 static void bar_reset(struct pci_dev *dev, int offset, void *data)
 220 {
 221         struct pci_bar_info *bar = data;
 222
 223         bar->which = 0;
 224 }
 225
 226 static void bar_release(struct pci_dev *dev, int offset, void *data)
 227 {
 228         kfree(data);
 229 }
 230
 231 static int xen_pcibk_read_vendor(struct pci_dev *dev, int offset,
 232                                u16 *value, void *data)
 233 {
 234         *value = dev->vendor;
 235
 236         return 0;
 237 }
 238
 239 static int xen_pcibk_read_device(struct pci_dev *dev, int offset,
 240                                u16 *value, void *data)
 241 {
 242         *value = dev->device;
 243
 244         return 0;
 245 }
 246
 247 static int interrupt_read(struct pci_dev *dev, int offset, u8 * value,
 248                           void *data)
 249 {
 250         *value = (u8) dev->irq;
 251
 252         return 0;
 253 }
 254
 255 static int bist_write(struct pci_dev *dev, int offset, u8 value, void *data)
 256 {
 257         u8 cur_value;
 258         int err;
 259
 260         err = pci_read_config_byte(dev, offset, &cur_value);
 261         if (err)
 262                 goto out;
 263
 264         if ((cur_value & ~PCI_BIST_START) == (value & ~PCI_BIST_START)
 265             || value == PCI_BIST_START)
 266                 err = pci_write_config_byte(dev, offset, value);
 267
 268 out:
 269         return err;
 270 }
 271
 272 static const struct config_field header_common[] = {
 273         {
 274          .offset    = PCI_VENDOR_ID,
 275          .size      = 2,
 276          .u.w.read  = xen_pcibk_read_vendor,
 277         },
 278         {
 279          .offset    = PCI_DEVICE_ID,
 280          .size      = 2,
 281          .u.w.read  = xen_pcibk_read_device,
 282         },
 283         {
 284          .offset    = PCI_COMMAND,
 285          .size      = 2,
 286          .u.w.read  = command_read,
 287          .u.w.write = command_write,
 288         },
 289         {
 290          .offset    = PCI_INTERRUPT_LINE,
 291          .size      = 1,
 292          .u.b.read  = interrupt_read,
 293         },
 294         {
 295          .offset    = PCI_INTERRUPT_PIN,
 296          .size      = 1,
 297          .u.b.read  = xen_pcibk_read_config_byte,
 298         },
 299         {
 300          /* Any side effects of letting driver domain control cache line? */
 301          .offset    = PCI_CACHE_LINE_SIZE,
 302          .size      = 1,
 303          .u.b.read  = xen_pcibk_read_config_byte,
 304          .u.b.write = xen_pcibk_write_config_byte,
 305         },
 306         {
 307          .offset    = PCI_LATENCY_TIMER,
 308          .size      = 1,
 309          .u.b.read  = xen_pcibk_read_config_byte,
 310         },
 311         {
 312          .offset    = PCI_BIST,
 313          .size      = 1,
 314          .u.b.read  = xen_pcibk_read_config_byte,
 315          .u.b.write = bist_write,
 316         },
 317         {}
 318 };
 319
 320 #define CFG_FIELD_BAR(reg_offset)                       \
 321         {                                               \
 322         .offset     = reg_offset,                       \
 323         .size       = 4,                                \
 324         .init       = bar_init,                         \
 325         .reset      = bar_reset,                        \
 326         .release    = bar_release,                      \
 327         .u.dw.read  = bar_read,                         \
 328         .u.dw.write = bar_write,                        \
 329         }
 330
 331 #define CFG_FIELD_ROM(reg_offset)                       \
 332         {                                               \
 333         .offset     = reg_offset,                       \
 334         .size       = 4,                                \
 335         .init       = rom_init,                         \
 336         .reset      = bar_reset,                        \
 337         .release    = bar_release,                      \
 338         .u.dw.read  = bar_read,                         \
 339         .u.dw.write = rom_write,                        \
 340         }
 341
 342 static const struct config_field header_0[] = {
 343         CFG_FIELD_BAR(PCI_BASE_ADDRESS_0),
 344         CFG_FIELD_BAR(PCI_BASE_ADDRESS_1),
 345         CFG_FIELD_BAR(PCI_BASE_ADDRESS_2),
 346         CFG_FIELD_BAR(PCI_BASE_ADDRESS_3),
 347         CFG_FIELD_BAR(PCI_BASE_ADDRESS_4),
 348         CFG_FIELD_BAR(PCI_BASE_ADDRESS_5),
 349         CFG_FIELD_ROM(PCI_ROM_ADDRESS),
 350         {}
 351 };
 352
 353 static const struct config_field header_1[] = {
 354         CFG_FIELD_BAR(PCI_BASE_ADDRESS_0),
 355         CFG_FIELD_BAR(PCI_BASE_ADDRESS_1),
 356         CFG_FIELD_ROM(PCI_ROM_ADDRESS1),
 357         {}
 358 };
 359
 360 int xen_pcibk_config_header_add_fields(struct pci_dev *dev)
 361 {
 362         int err;
 363
 364         err = xen_pcibk_config_add_fields(dev, header_common);
 365         if (err)
 366                 goto out;
 367
 368         switch (dev->hdr_type) {
 369         case PCI_HEADER_TYPE_NORMAL:
 370                 err = xen_pcibk_config_add_fields(dev, header_0);
 371                 break;
 372
 373         case PCI_HEADER_TYPE_BRIDGE:
 374                 err = xen_pcibk_config_add_fields(dev, header_1);
 375                 break;
 376
 377         default:
 378                 err = -EINVAL;
 379                 printk(KERN_ERR DRV_NAME ": %s: Unsupported header type %d!\n",
 380                        pci_name(dev), dev->hdr_type);
 381                 break;
 382         }
 383
 384 out:
 385         return err;
 386 }