arch/ia64/sn/pci/tioca_provider.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 2003-2005 Silicon Graphics, Inc.  All Rights Reserved.
   7  */
   8
   9 #include <linux/types.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/pci.h>
  12 #include <asm/sn/sn_sal.h>
  13 #include <asm/sn/addrs.h>
  14 #include <asm/sn/io.h>
  15 #include <asm/sn/pcidev.h>
  16 #include <asm/sn/pcibus_provider_defs.h>
  17 #include <asm/sn/tioca_provider.h>
  18
  19 u32 tioca_gart_found;
  20 EXPORT_SYMBOL(tioca_gart_found);        /* used by agp-sgi */
  21
  22 LIST_HEAD(tioca_list);
  23 EXPORT_SYMBOL(tioca_list);      /* used by agp-sgi */
  24
  25 static int tioca_gart_init(struct tioca_kernel *);
  26
  27 /**
  28  * tioca_gart_init - Initialize SGI TIOCA GART
  29  * @tioca_common: ptr to common prom/kernel struct identifying the
  30  *
  31  * If the indicated tioca has devices present, initialize its associated
  32  * GART MMR's and kernel memory.
  33  */
  34 static int
  35 tioca_gart_init(struct tioca_kernel *tioca_kern)
  36 {
  37         u64 ap_reg;
  38         u64 offset;
  39         struct page *tmp;
  40         struct tioca_common *tioca_common;
  41         struct tioca __iomem *ca_base;
  42
  43         tioca_common = tioca_kern->ca_common;
  44         ca_base = (struct tioca __iomem *)tioca_common->ca_common.bs_base;
  45
  46         if (list_empty(tioca_kern->ca_devices))
  47                 return 0;
  48
  49         ap_reg = 0;
  50
  51         /*
  52          * Validate aperature size
  53          */
  54
  55         switch (CA_APERATURE_SIZE >> 20) {
  56         case 4:
  57                 ap_reg |= (0x3ff << CA_GART_AP_SIZE_SHFT);      /* 4MB */
  58                 break;
  59         case 8:
  60                 ap_reg |= (0x3fe << CA_GART_AP_SIZE_SHFT);      /* 8MB */
  61                 break;
  62         case 16:
  63                 ap_reg |= (0x3fc << CA_GART_AP_SIZE_SHFT);      /* 16MB */
  64                 break;
  65         case 32:
  66                 ap_reg |= (0x3f8 << CA_GART_AP_SIZE_SHFT);      /* 32 MB */
  67                 break;
  68         case 64:
  69                 ap_reg |= (0x3f0 << CA_GART_AP_SIZE_SHFT);      /* 64 MB */
  70                 break;
  71         case 128:
  72                 ap_reg |= (0x3e0 << CA_GART_AP_SIZE_SHFT);      /* 128 MB */
  73                 break;
  74         case 256:
  75                 ap_reg |= (0x3c0 << CA_GART_AP_SIZE_SHFT);      /* 256 MB */
  76                 break;
  77         case 512:
  78                 ap_reg |= (0x380 << CA_GART_AP_SIZE_SHFT);      /* 512 MB */
  79                 break;
  80         case 1024:
  81                 ap_reg |= (0x300 << CA_GART_AP_SIZE_SHFT);      /* 1GB */
  82                 break;
  83         case 2048:
  84                 ap_reg |= (0x200 << CA_GART_AP_SIZE_SHFT);      /* 2GB */
  85                 break;
  86         case 4096:
  87                 ap_reg |= (0x000 << CA_GART_AP_SIZE_SHFT);      /* 4 GB */
  88                 break;
  89         default:
  90                 printk(KERN_ERR "%s:  Invalid CA_APERATURE_SIZE "
  91                        "0x%lx\n", __FUNCTION__, (ulong) CA_APERATURE_SIZE);
  92                 return -1;
  93         }
  94
  95         /*
  96          * Set up other aperature parameters
  97          */
  98
  99         if (PAGE_SIZE >= 16384) {
 100                 tioca_kern->ca_ap_pagesize = 16384;
 101                 ap_reg |= CA_GART_PAGE_SIZE;
 102         } else {
 103                 tioca_kern->ca_ap_pagesize = 4096;
 104         }
 105
 106         tioca_kern->ca_ap_size = CA_APERATURE_SIZE;
 107         tioca_kern->ca_ap_bus_base = CA_APERATURE_BASE;
 108         tioca_kern->ca_gart_entries =
 109             tioca_kern->ca_ap_size / tioca_kern->ca_ap_pagesize;
 110
 111         ap_reg |= (CA_GART_AP_ENB_AGP | CA_GART_AP_ENB_PCI);
 112         ap_reg |= tioca_kern->ca_ap_bus_base;
 113
 114         /*
 115          * Allocate and set up the GART
 116          */
 117
 118         tioca_kern->ca_gart_size = tioca_kern->ca_gart_entries * sizeof(u64);
 119         tmp =
 120             alloc_pages_node(tioca_kern->ca_closest_node,
 121                              GFP_KERNEL | __GFP_ZERO,
 122                              get_order(tioca_kern->ca_gart_size));
 123
 124         if (!tmp) {
 125                 printk(KERN_ERR "%s:  Could not allocate "
 126                        "%lu bytes (order %d) for GART\n",
 127                        __FUNCTION__,
 128                        tioca_kern->ca_gart_size,
 129                        get_order(tioca_kern->ca_gart_size));
 130                 return -ENOMEM;
 131         }
 132
 133         tioca_kern->ca_gart = page_address(tmp);
 134         tioca_kern->ca_gart_coretalk_addr =
 135             PHYS_TO_TIODMA(virt_to_phys(tioca_kern->ca_gart));
 136
 137         /*
 138          * Compute PCI/AGP convenience fields
 139          */
 140
 141         offset = CA_PCI32_MAPPED_BASE - CA_APERATURE_BASE;
 142         tioca_kern->ca_pciap_base = CA_PCI32_MAPPED_BASE;
 143         tioca_kern->ca_pciap_size = CA_PCI32_MAPPED_SIZE;
 144         tioca_kern->ca_pcigart_start = offset / tioca_kern->ca_ap_pagesize;
 145         tioca_kern->ca_pcigart_base =
 146             tioca_kern->ca_gart_coretalk_addr + offset;
 147         tioca_kern->ca_pcigart =
 148             &tioca_kern->ca_gart[tioca_kern->ca_pcigart_start];
 149         tioca_kern->ca_pcigart_entries =
 150             tioca_kern->ca_pciap_size / tioca_kern->ca_ap_pagesize;
 151         tioca_kern->ca_pcigart_pagemap =
 152             kzalloc(tioca_kern->ca_pcigart_entries / 8, GFP_KERNEL);
 153         if (!tioca_kern->ca_pcigart_pagemap) {
 154                 free_pages((unsigned long)tioca_kern->ca_gart,
 155                            get_order(tioca_kern->ca_gart_size));
 156                 return -1;
 157         }
 158
 159         offset = CA_AGP_MAPPED_BASE - CA_APERATURE_BASE;
 160         tioca_kern->ca_gfxap_base = CA_AGP_MAPPED_BASE;
 161         tioca_kern->ca_gfxap_size = CA_AGP_MAPPED_SIZE;
 162         tioca_kern->ca_gfxgart_start = offset / tioca_kern->ca_ap_pagesize;
 163         tioca_kern->ca_gfxgart_base =
 164             tioca_kern->ca_gart_coretalk_addr + offset;
 165         tioca_kern->ca_gfxgart =
 166             &tioca_kern->ca_gart[tioca_kern->ca_gfxgart_start];
 167         tioca_kern->ca_gfxgart_entries =
 168             tioca_kern->ca_gfxap_size / tioca_kern->ca_ap_pagesize;
 169
 170         /*
 171          * various control settings:
 172          *      use agp op-combining
 173          *      use GET semantics to fetch memory
 174          *      participate in coherency domain
 175          *      DISABLE GART PREFETCHING due to hw bug tracked in SGI PV930029
 176          */
 177
 178         __sn_setq_relaxed(&ca_base->ca_control1,
 179                         CA_AGPDMA_OP_ENB_COMBDELAY);    /* PV895469 ? */
 180         __sn_clrq_relaxed(&ca_base->ca_control2, CA_GART_MEM_PARAM);
 181         __sn_setq_relaxed(&ca_base->ca_control2,
 182                         (0x2ull << CA_GART_MEM_PARAM_SHFT));
 183         tioca_kern->ca_gart_iscoherent = 1;
 184         __sn_clrq_relaxed(&ca_base->ca_control2,
 185                         (CA_GART_WR_PREFETCH_ENB | CA_GART_RD_PREFETCH_ENB));
 186
 187         /*
 188          * Unmask GART fetch error interrupts.  Clear residual errors first.
 189          */
 190
 191         writeq(CA_GART_FETCH_ERR, &ca_base->ca_int_status_alias);
 192         writeq(CA_GART_FETCH_ERR, &ca_base->ca_mult_error_alias);
 193         __sn_clrq_relaxed(&ca_base->ca_int_mask, CA_GART_FETCH_ERR);
 194
 195         /*
 196          * Program the aperature and gart registers in TIOCA
 197          */
 198
 199         writeq(ap_reg, &ca_base->ca_gart_aperature);
 200         writeq(tioca_kern->ca_gart_coretalk_addr|1, &ca_base->ca_gart_ptr_table);
 201
 202         return 0;
 203 }
 204
 205 /**
 206  * tioca_fastwrite_enable - enable AGP FW for a tioca and its functions
 207  * @tioca_kernel: structure representing the CA
 208  *
 209  * Given a CA, scan all attached functions making sure they all support
 210  * FastWrite.  If so, enable FastWrite for all functions and the CA itself.
 211  */
 212
 213 void
 214 tioca_fastwrite_enable(struct tioca_kernel *tioca_kern)
 215 {
 216         int cap_ptr;
 217         u32 reg;
 218         struct tioca __iomem *tioca_base;
 219         struct pci_dev *pdev;
 220         struct tioca_common *common;
 221
 222         common = tioca_kern->ca_common;
 223
 224         /*
 225          * Scan all vga controllers on this bus making sure they all
 226          * support FW.  If not, return.
 227          */
 228
 229         list_for_each_entry(pdev, tioca_kern->ca_devices, bus_list) {
 230                 if (pdev->class != (PCI_CLASS_DISPLAY_VGA << 8))
 231                         continue;
 232
 233                 cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
 234                 if (!cap_ptr)
 235                         return; /* no AGP CAP means no FW */
 236
 237                 pci_read_config_dword(pdev, cap_ptr + PCI_AGP_STATUS, &reg);
 238                 if (!(reg & PCI_AGP_STATUS_FW))
 239                         return; /* function doesn't support FW */
 240         }
 241
 242         /*
 243          * Set fw for all vga fn's
 244          */
 245
 246         list_for_each_entry(pdev, tioca_kern->ca_devices, bus_list) {
 247                 if (pdev->class != (PCI_CLASS_DISPLAY_VGA << 8))
 248                         continue;
 249
 250                 cap_ptr = pci_find_capability(pdev, PCI_CAP_ID_AGP);
 251                 pci_read_config_dword(pdev, cap_ptr + PCI_AGP_COMMAND, &reg);
 252                 reg |= PCI_AGP_COMMAND_FW;
 253                 pci_write_config_dword(pdev, cap_ptr + PCI_AGP_COMMAND, reg);
 254         }
 255
 256         /*
 257          * Set ca's fw to match
 258          */
 259
 260         tioca_base = (struct tioca __iomem*)common->ca_common.bs_base;
 261         __sn_setq_relaxed(&tioca_base->ca_control1, CA_AGP_FW_ENABLE);
 262 }
 263
 264 EXPORT_SYMBOL(tioca_fastwrite_enable);  /* used by agp-sgi */
 265
 266 /**
 267  * tioca_dma_d64 - create a DMA mapping using 64-bit direct mode
 268  * @paddr: system physical address
 269  *
 270  * Map @paddr into 64-bit CA bus space.  No device context is necessary.
 271  * Bits 53:0 come from the coretalk address.  We just need to mask in the
 272  * following optional bits of the 64-bit pci address:
 273  *
 274  * 63:60 - Coretalk Packet Type -  0x1 for Mem Get/Put (coherent)
 275  *                                 0x2 for PIO (non-coherent)
 276  *                                 We will always use 0x1
 277  * 55:55 - Swap bytes              Currently unused
 278  */
 279 static u64
 280 tioca_dma_d64(unsigned long paddr)
 281 {
 282         dma_addr_t bus_addr;
 283
 284         bus_addr = PHYS_TO_TIODMA(paddr);
 285
 286         BUG_ON(!bus_addr);
 287         BUG_ON(bus_addr >> 54);
 288
 289         /* Set upper nibble to Cache Coherent Memory op */
 290         bus_addr |= (1UL << 60);
 291
 292         return bus_addr;
 293 }
 294
 295 /**
 296  * tioca_dma_d48 - create a DMA mapping using 48-bit direct mode
 297  * @pdev: linux pci_dev representing the function
 298  * @paddr: system physical address
 299  *
 300  * Map @paddr into 64-bit bus space of the CA associated with @pcidev_info.
 301  *
 302  * The CA agp 48 bit direct address falls out as follows:
 303  *
 304  * When direct mapping AGP addresses, the 48 bit AGP address is
 305  * constructed as follows:
 306  *
 307  * [47:40] - Low 8 bits of the page Node ID extracted from coretalk
 308  *              address [47:40].  The upper 8 node bits are fixed
 309  *              and come from the xxx register bits [5:0]
 310  * [39:38] - Chiplet ID extracted from coretalk address [39:38]
 311  * [37:00] - node offset extracted from coretalk address [37:00]
 312  *
 313  * Since the node id in general will be non-zero, and the chiplet id
 314  * will always be non-zero, it follows that the device must support
 315  * a dma mask of at least 0xffffffffff (40 bits) to target node 0
 316  * and in general should be 0xffffffffffff (48 bits) to target nodes
 317  * up to 255.  Nodes above 255 need the support of the xxx register,
 318  * and so a given CA can only directly target nodes in the range
 319  * xxx - xxx+255.
 320  */
 321 static u64
 322 tioca_dma_d48(struct pci_dev *pdev, u64 paddr)
 323 {
 324         struct tioca_common *tioca_common;
 325         struct tioca __iomem *ca_base;
 326         u64 ct_addr;
 327         dma_addr_t bus_addr;
 328         u32 node_upper;
 329         u64 agp_dma_extn;
 330         struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(pdev);
 331
 332         tioca_common = (struct tioca_common *)pcidev_info->pdi_pcibus_info;
 333         ca_base = (struct tioca __iomem *)tioca_common->ca_common.bs_base;
 334
 335         ct_addr = PHYS_TO_TIODMA(paddr);
 336         if (!ct_addr)
 337                 return 0;
 338
 339         bus_addr = (dma_addr_t) (ct_addr & 0xffffffffffffUL);
 340         node_upper = ct_addr >> 48;
 341
 342         if (node_upper > 64) {
 343                 printk(KERN_ERR "%s:  coretalk addr 0x%p node id out "
 344                        "of range\n", __FUNCTION__, (void *)ct_addr);
 345                 return 0;
 346         }
 347
 348         agp_dma_extn = __sn_readq_relaxed(&ca_base->ca_agp_dma_addr_extn);
 349         if (node_upper != (agp_dma_extn >> CA_AGP_DMA_NODE_ID_SHFT)) {
 350                 printk(KERN_ERR "%s:  coretalk upper node (%u) "
 351                        "mismatch with ca_agp_dma_addr_extn (%lu)\n",
 352                        __FUNCTION__,
 353                        node_upper, (agp_dma_extn >> CA_AGP_DMA_NODE_ID_SHFT));
 354                 return 0;
 355         }
 356
 357         return bus_addr;
 358 }
 359
 360 /**
 361  * tioca_dma_mapped - create a DMA mapping using a CA GART
 362  * @pdev: linux pci_dev representing the function
 363  * @paddr: host physical address to map
 364  * @req_size: len (bytes) to map
 365  *
 366  * Map @paddr into CA address space using the GART mechanism.  The mapped
 367  * dma_addr_t is guaranteed to be contiguous in CA bus space.
 368  */
 369 static dma_addr_t
 370 tioca_dma_mapped(struct pci_dev *pdev, u64 paddr, size_t req_size)
 371 {
 372         int i, ps, ps_shift, entry, entries, mapsize, last_entry;
 373         u64 xio_addr, end_xio_addr;
 374         struct tioca_common *tioca_common;
 375         struct tioca_kernel *tioca_kern;
 376         dma_addr_t bus_addr = 0;
 377         struct tioca_dmamap *ca_dmamap;
 378         void *map;
 379         unsigned long flags;
 380         struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(pdev);
 381
 382         tioca_common = (struct tioca_common *)pcidev_info->pdi_pcibus_info;
 383         tioca_kern = (struct tioca_kernel *)tioca_common->ca_kernel_private;
 384
 385         xio_addr = PHYS_TO_TIODMA(paddr);
 386         if (!xio_addr)
 387                 return 0;
 388
 389         spin_lock_irqsave(&tioca_kern->ca_lock, flags);
 390
 391         /*
 392          * allocate a map struct
 393          */
 394
 395         ca_dmamap = kzalloc(sizeof(struct tioca_dmamap), GFP_ATOMIC);
 396         if (!ca_dmamap)
 397                 goto map_return;
 398
 399         /*
 400          * Locate free entries that can hold req_size.  Account for
 401          * unaligned start/length when allocating.
 402          */
 403
 404         ps = tioca_kern->ca_ap_pagesize;        /* will be power of 2 */
 405         ps_shift = ffs(ps) - 1;
 406         end_xio_addr = xio_addr + req_size - 1;
 407
 408         entries = (end_xio_addr >> ps_shift) - (xio_addr >> ps_shift) + 1;
 409
 410         map = tioca_kern->ca_pcigart_pagemap;
 411         mapsize = tioca_kern->ca_pcigart_entries;
 412
 413         entry = find_first_zero_bit(map, mapsize);
 414         while (entry < mapsize) {
 415                 last_entry = find_next_bit(map, mapsize, entry);
 416
 417                 if (last_entry - entry >= entries)
 418                         break;
 419
 420                 entry = find_next_zero_bit(map, mapsize, last_entry);
 421         }
 422
 423         if (entry > mapsize)
 424                 goto map_return;
 425
 426         for (i = 0; i < entries; i++)
 427                 set_bit(entry + i, map);
 428
 429         bus_addr = tioca_kern->ca_pciap_base + (entry * ps);
 430
 431         ca_dmamap->cad_dma_addr = bus_addr;
 432         ca_dmamap->cad_gart_size = entries;
 433         ca_dmamap->cad_gart_entry = entry;
 434         list_add(&ca_dmamap->cad_list, &tioca_kern->ca_dmamaps);
 435
 436         if (xio_addr % ps) {
 437                 tioca_kern->ca_pcigart[entry] = tioca_paddr_to_gart(xio_addr);
 438                 bus_addr += xio_addr & (ps - 1);
 439                 xio_addr &= ~(ps - 1);
 440                 xio_addr += ps;
 441                 entry++;
 442         }
 443
 444         while (xio_addr < end_xio_addr) {
 445                 tioca_kern->ca_pcigart[entry] = tioca_paddr_to_gart(xio_addr);
 446                 xio_addr += ps;
 447                 entry++;
 448         }
 449
 450         tioca_tlbflush(tioca_kern);
 451
 452 map_return:
 453         spin_unlock_irqrestore(&tioca_kern->ca_lock, flags);
 454         return bus_addr;
 455 }
 456
 457 /**
 458  * tioca_dma_unmap - release CA mapping resources
 459  * @pdev: linux pci_dev representing the function
 460  * @bus_addr: bus address returned by an earlier tioca_dma_map
 461  * @dir: mapping direction (unused)
 462  *
 463  * Locate mapping resources associated with @bus_addr and release them.
 464  * For mappings created using the direct modes (64 or 48) there are no
 465  * resources to release.
 466  */
 467 static void
 468 tioca_dma_unmap(struct pci_dev *pdev, dma_addr_t bus_addr, int dir)
 469 {
 470         int i, entry;
 471         struct tioca_common *tioca_common;
 472         struct tioca_kernel *tioca_kern;
 473         struct tioca_dmamap *map;
 474         struct pcidev_info *pcidev_info = SN_PCIDEV_INFO(pdev);
 475         unsigned long flags;
 476
 477         tioca_common = (struct tioca_common *)pcidev_info->pdi_pcibus_info;
 478         tioca_kern = (struct tioca_kernel *)tioca_common->ca_kernel_private;
 479
 480         /* return straight away if this isn't be a mapped address */
 481
 482         if (bus_addr < tioca_kern->ca_pciap_base ||
 483             bus_addr >= (tioca_kern->ca_pciap_base + tioca_kern->ca_pciap_size))
 484                 return;
 485
 486         spin_lock_irqsave(&tioca_kern->ca_lock, flags);
 487
 488         list_for_each_entry(map, &tioca_kern->ca_dmamaps, cad_list)
 489             if (map->cad_dma_addr == bus_addr)
 490                 break;
 491
 492         BUG_ON(map == NULL);
 493
 494         entry = map->cad_gart_entry;
 495
 496         for (i = 0; i < map->cad_gart_size; i++, entry++) {
 497                 clear_bit(entry, tioca_kern->ca_pcigart_pagemap);
 498                 tioca_kern->ca_pcigart[entry] = 0;
 499         }
 500         tioca_tlbflush(tioca_kern);
 501
 502         list_del(&map->cad_list);
 503         spin_unlock_irqrestore(&tioca_kern->ca_lock, flags);
 504         kfree(map);
 505 }
 506
 507 /**
 508  * tioca_dma_map - map pages for PCI DMA
 509  * @pdev: linux pci_dev representing the function
 510  * @paddr: host physical address to map
 511  * @byte_count: bytes to map
 512  *
 513  * This is the main wrapper for mapping host physical pages to CA PCI space.
 514  * The mapping mode used is based on the devices dma_mask.  As a last resort
 515  * use the GART mapped mode.
 516  */
 517 static u64
 518 tioca_dma_map(struct pci_dev *pdev, u64 paddr, size_t byte_count, int dma_flags)
 519 {
 520         u64 mapaddr;
 521
 522         /*
 523          * Not supported for now ...
 524          */
 525         if (dma_flags & SN_DMA_MSI)
 526                 return 0;
 527
 528         /*
 529          * If card is 64 or 48 bit addressable, use a direct mapping.  32
 530          * bit direct is so restrictive w.r.t. where the memory resides that
 531          * we don't use it even though CA has some support.
 532          */
 533
 534         if (pdev->dma_mask == ~0UL)
 535                 mapaddr = tioca_dma_d64(paddr);
 536         else if (pdev->dma_mask == 0xffffffffffffUL)
 537                 mapaddr = tioca_dma_d48(pdev, paddr);
 538         else
 539                 mapaddr = 0;
 540
 541         /* Last resort ... use PCI portion of CA GART */
 542
 543         if (mapaddr == 0)
 544                 mapaddr = tioca_dma_mapped(pdev, paddr, byte_count);
 545
 546         return mapaddr;
 547 }
 548
 549 /**
 550  * tioca_error_intr_handler - SGI TIO CA error interrupt handler
 551  * @irq: unused
 552  * @arg: pointer to tioca_common struct for the given CA
 553  *
 554  * Handle a CA error interrupt.  Simply a wrapper around a SAL call which
 555  * defers processing to the SGI prom.
 556  */
 557 static irqreturn_t
 558 tioca_error_intr_handler(int irq, void *arg)
 559 {
 560         struct tioca_common *soft = arg;
 561         struct ia64_sal_retval ret_stuff;
 562         u64 segment;
 563         u64 busnum;
 564         ret_stuff.status = 0;
 565         ret_stuff.v0 = 0;
 566
 567         segment = soft->ca_common.bs_persist_segment;
 568         busnum = soft->ca_common.bs_persist_busnum;
 569
 570         SAL_CALL_NOLOCK(ret_stuff,
 571                         (u64) SN_SAL_IOIF_ERROR_INTERRUPT,
 572                         segment, busnum, 0, 0, 0, 0, 0);
 573
 574         return IRQ_HANDLED;
 575 }
 576
 577 /**
 578  * tioca_bus_fixup - perform final PCI fixup for a TIO CA bus
 579  * @prom_bussoft: Common prom/kernel struct representing the bus
 580  *
 581  * Replicates the tioca_common pointed to by @prom_bussoft in kernel
 582  * space.  Allocates and initializes a kernel-only area for a given CA,
 583  * and sets up an irq for handling CA error interrupts.
 584  *
 585  * On successful setup, returns the kernel version of tioca_common back to
 586  * the caller.
 587  */
 588 static void *
 589 tioca_bus_fixup(struct pcibus_bussoft *prom_bussoft, struct pci_controller *controller)
 590 {
 591         struct tioca_common *tioca_common;
 592         struct tioca_kernel *tioca_kern;
 593         struct pci_bus *bus;
 594
 595         /* sanity check prom rev */
 596
 597         if (is_shub1() && sn_sal_rev() < 0x0406) {
 598                 printk
 599                     (KERN_ERR "%s:  SGI prom rev 4.06 or greater required "
 600                      "for tioca support\n", __FUNCTION__);
 601                 return NULL;
 602         }
 603
 604         /*
 605          * Allocate kernel bus soft and copy from prom.
 606          */
 607
 608         tioca_common = kzalloc(sizeof(struct tioca_common), GFP_KERNEL);
 609         if (!tioca_common)
 610                 return NULL;
 611
 612         memcpy(tioca_common, prom_bussoft, sizeof(struct tioca_common));
 613         tioca_common->ca_common.bs_base = (unsigned long)
 614                 ioremap(REGION_OFFSET(tioca_common->ca_common.bs_base),
 615                         sizeof(struct tioca_common));
 616
 617         /* init kernel-private area */
 618
 619         tioca_kern = kzalloc(sizeof(struct tioca_kernel), GFP_KERNEL);
 620         if (!tioca_kern) {
 621                 kfree(tioca_common);
 622                 return NULL;
 623         }
 624
 625         tioca_kern->ca_common = tioca_common;
 626         spin_lock_init(&tioca_kern->ca_lock);
 627         INIT_LIST_HEAD(&tioca_kern->ca_dmamaps);
 628         tioca_kern->ca_closest_node =
 629             nasid_to_cnodeid(tioca_common->ca_closest_nasid);
 630         tioca_common->ca_kernel_private = (u64) tioca_kern;
 631
 632         bus = pci_find_bus(tioca_common->ca_common.bs_persist_segment,
 633                 tioca_common->ca_common.bs_persist_busnum);
 634         BUG_ON(!bus);
 635         tioca_kern->ca_devices = &bus->devices;
 636
 637         /* init GART */
 638
 639         if (tioca_gart_init(tioca_kern) < 0) {
 640                 kfree(tioca_kern);
 641                 kfree(tioca_common);
 642                 return NULL;
 643         }
 644
 645         tioca_gart_found++;
 646         list_add(&tioca_kern->ca_list, &tioca_list);
 647
 648         if (request_irq(SGI_TIOCA_ERROR,
 649                         tioca_error_intr_handler,
 650                         IRQF_SHARED, "TIOCA error", (void *)tioca_common))
 651                 printk(KERN_WARNING
 652                        "%s:  Unable to get irq %d.  "
 653                        "Error interrupts won't be routed for TIOCA bus %d\n",
 654                        __FUNCTION__, SGI_TIOCA_ERROR,
 655                        (int)tioca_common->ca_common.bs_persist_busnum);
 656
 657         /* Setup locality information */
 658         controller->node = tioca_kern->ca_closest_node;
 659         return tioca_common;
 660 }
 661
 662 static struct sn_pcibus_provider tioca_pci_interfaces = {
 663         .dma_map = tioca_dma_map,
 664         .dma_map_consistent = tioca_dma_map,
 665         .dma_unmap = tioca_dma_unmap,
 666         .bus_fixup = tioca_bus_fixup,
 667         .force_interrupt = NULL,
 668         .target_interrupt = NULL
 669 };
 670
 671 /**
 672  * tioca_init_provider - init SN PCI provider ops for TIO CA
 673  */
 674 int
 675 tioca_init_provider(void)
 676 {
 677         sn_pci_provider[PCIIO_ASIC_TYPE_TIOCA] = &tioca_pci_interfaces;
 678         return 0;
 679 }