linux/arch/powerpc/platforms/pseries/vio.c
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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * IBM PowerPC Virtual I/O Infrastructure Support.
   4 *
   5 *    Copyright (c) 2003,2008 IBM Corp.
   6 *     Dave Engebretsen engebret@us.ibm.com
   7 *     Santiago Leon santil@us.ibm.com
   8 *     Hollis Blanchard <hollisb@us.ibm.com>
   9 *     Stephen Rothwell
  10 *     Robert Jennings <rcjenn@us.ibm.com>
  11 */
  12
  13#include <linux/cpu.h>
  14#include <linux/types.h>
  15#include <linux/delay.h>
  16#include <linux/stat.h>
  17#include <linux/device.h>
  18#include <linux/init.h>
  19#include <linux/slab.h>
  20#include <linux/console.h>
  21#include <linux/export.h>
  22#include <linux/mm.h>
  23#include <linux/dma-map-ops.h>
  24#include <linux/kobject.h>
  25#include <linux/kexec.h>
  26
  27#include <asm/iommu.h>
  28#include <asm/dma.h>
  29#include <asm/vio.h>
  30#include <asm/prom.h>
  31#include <asm/firmware.h>
  32#include <asm/tce.h>
  33#include <asm/page.h>
  34#include <asm/hvcall.h>
  35#include <asm/machdep.h>
  36
  37static struct vio_dev vio_bus_device  = { /* fake "parent" device */
  38        .name = "vio",
  39        .type = "",
  40        .dev.init_name = "vio",
  41        .dev.bus = &vio_bus_type,
  42};
  43
  44#ifdef CONFIG_PPC_SMLPAR
  45/**
  46 * vio_cmo_pool - A pool of IO memory for CMO use
  47 *
  48 * @size: The size of the pool in bytes
  49 * @free: The amount of free memory in the pool
  50 */
  51struct vio_cmo_pool {
  52        size_t size;
  53        size_t free;
  54};
  55
  56/* How many ms to delay queued balance work */
  57#define VIO_CMO_BALANCE_DELAY 100
  58
  59/* Portion out IO memory to CMO devices by this chunk size */
  60#define VIO_CMO_BALANCE_CHUNK 131072
  61
  62/**
  63 * vio_cmo_dev_entry - A device that is CMO-enabled and requires entitlement
  64 *
  65 * @vio_dev: struct vio_dev pointer
  66 * @list: pointer to other devices on bus that are being tracked
  67 */
  68struct vio_cmo_dev_entry {
  69        struct vio_dev *viodev;
  70        struct list_head list;
  71};
  72
  73/**
  74 * vio_cmo - VIO bus accounting structure for CMO entitlement
  75 *
  76 * @lock: spinlock for entire structure
  77 * @balance_q: work queue for balancing system entitlement
  78 * @device_list: list of CMO-enabled devices requiring entitlement
  79 * @entitled: total system entitlement in bytes
  80 * @reserve: pool of memory from which devices reserve entitlement, incl. spare
  81 * @excess: pool of excess entitlement not needed for device reserves or spare
  82 * @spare: IO memory for device hotplug functionality
  83 * @min: minimum necessary for system operation
  84 * @desired: desired memory for system operation
  85 * @curr: bytes currently allocated
  86 * @high: high water mark for IO data usage
  87 */
  88static struct vio_cmo {
  89        spinlock_t lock;
  90        struct delayed_work balance_q;
  91        struct list_head device_list;
  92        size_t entitled;
  93        struct vio_cmo_pool reserve;
  94        struct vio_cmo_pool excess;
  95        size_t spare;
  96        size_t min;
  97        size_t desired;
  98        size_t curr;
  99        size_t high;
 100} vio_cmo;
 101
 102/**
 103 * vio_cmo_OF_devices - Count the number of OF devices that have DMA windows
 104 */
 105static int vio_cmo_num_OF_devs(void)
 106{
 107        struct device_node *node_vroot;
 108        int count = 0;
 109
 110        /*
 111         * Count the number of vdevice entries with an
 112         * ibm,my-dma-window OF property
 113         */
 114        node_vroot = of_find_node_by_name(NULL, "vdevice");
 115        if (node_vroot) {
 116                struct device_node *of_node;
 117                struct property *prop;
 118
 119                for_each_child_of_node(node_vroot, of_node) {
 120                        prop = of_find_property(of_node, "ibm,my-dma-window",
 121                                               NULL);
 122                        if (prop)
 123                                count++;
 124                }
 125        }
 126        of_node_put(node_vroot);
 127        return count;
 128}
 129
 130/**
 131 * vio_cmo_alloc - allocate IO memory for CMO-enable devices
 132 *
 133 * @viodev: VIO device requesting IO memory
 134 * @size: size of allocation requested
 135 *
 136 * Allocations come from memory reserved for the devices and any excess
 137 * IO memory available to all devices.  The spare pool used to service
 138 * hotplug must be equal to %VIO_CMO_MIN_ENT for the excess pool to be
 139 * made available.
 140 *
 141 * Return codes:
 142 *  0 for successful allocation and -ENOMEM for a failure
 143 */
 144static inline int vio_cmo_alloc(struct vio_dev *viodev, size_t size)
 145{
 146        unsigned long flags;
 147        size_t reserve_free = 0;
 148        size_t excess_free = 0;
 149        int ret = -ENOMEM;
 150
 151        spin_lock_irqsave(&vio_cmo.lock, flags);
 152
 153        /* Determine the amount of free entitlement available in reserve */
 154        if (viodev->cmo.entitled > viodev->cmo.allocated)
 155                reserve_free = viodev->cmo.entitled - viodev->cmo.allocated;
 156
 157        /* If spare is not fulfilled, the excess pool can not be used. */
 158        if (vio_cmo.spare >= VIO_CMO_MIN_ENT)
 159                excess_free = vio_cmo.excess.free;
 160
 161        /* The request can be satisfied */
 162        if ((reserve_free + excess_free) >= size) {
 163                vio_cmo.curr += size;
 164                if (vio_cmo.curr > vio_cmo.high)
 165                        vio_cmo.high = vio_cmo.curr;
 166                viodev->cmo.allocated += size;
 167                size -= min(reserve_free, size);
 168                vio_cmo.excess.free -= size;
 169                ret = 0;
 170        }
 171
 172        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 173        return ret;
 174}
 175
 176/**
 177 * vio_cmo_dealloc - deallocate IO memory from CMO-enable devices
 178 * @viodev: VIO device freeing IO memory
 179 * @size: size of deallocation
 180 *
 181 * IO memory is freed by the device back to the correct memory pools.
 182 * The spare pool is replenished first from either memory pool, then
 183 * the reserve pool is used to reduce device entitlement, the excess
 184 * pool is used to increase the reserve pool toward the desired entitlement
 185 * target, and then the remaining memory is returned to the pools.
 186 *
 187 */
 188static inline void vio_cmo_dealloc(struct vio_dev *viodev, size_t size)
 189{
 190        unsigned long flags;
 191        size_t spare_needed = 0;
 192        size_t excess_freed = 0;
 193        size_t reserve_freed = size;
 194        size_t tmp;
 195        int balance = 0;
 196
 197        spin_lock_irqsave(&vio_cmo.lock, flags);
 198        vio_cmo.curr -= size;
 199
 200        /* Amount of memory freed from the excess pool */
 201        if (viodev->cmo.allocated > viodev->cmo.entitled) {
 202                excess_freed = min(reserve_freed, (viodev->cmo.allocated -
 203                                                   viodev->cmo.entitled));
 204                reserve_freed -= excess_freed;
 205        }
 206
 207        /* Remove allocation from device */
 208        viodev->cmo.allocated -= (reserve_freed + excess_freed);
 209
 210        /* Spare is a subset of the reserve pool, replenish it first. */
 211        spare_needed = VIO_CMO_MIN_ENT - vio_cmo.spare;
 212
 213        /*
 214         * Replenish the spare in the reserve pool from the excess pool.
 215         * This moves entitlement into the reserve pool.
 216         */
 217        if (spare_needed && excess_freed) {
 218                tmp = min(excess_freed, spare_needed);
 219                vio_cmo.excess.size -= tmp;
 220                vio_cmo.reserve.size += tmp;
 221                vio_cmo.spare += tmp;
 222                excess_freed -= tmp;
 223                spare_needed -= tmp;
 224                balance = 1;
 225        }
 226
 227        /*
 228         * Replenish the spare in the reserve pool from the reserve pool.
 229         * This removes entitlement from the device down to VIO_CMO_MIN_ENT,
 230         * if needed, and gives it to the spare pool. The amount of used
 231         * memory in this pool does not change.
 232         */
 233        if (spare_needed && reserve_freed) {
 234                tmp = min3(spare_needed, reserve_freed, (viodev->cmo.entitled - VIO_CMO_MIN_ENT));
 235
 236                vio_cmo.spare += tmp;
 237                viodev->cmo.entitled -= tmp;
 238                reserve_freed -= tmp;
 239                spare_needed -= tmp;
 240                balance = 1;
 241        }
 242
 243        /*
 244         * Increase the reserve pool until the desired allocation is met.
 245         * Move an allocation freed from the excess pool into the reserve
 246         * pool and schedule a balance operation.
 247         */
 248        if (excess_freed && (vio_cmo.desired > vio_cmo.reserve.size)) {
 249                tmp = min(excess_freed, (vio_cmo.desired - vio_cmo.reserve.size));
 250
 251                vio_cmo.excess.size -= tmp;
 252                vio_cmo.reserve.size += tmp;
 253                excess_freed -= tmp;
 254                balance = 1;
 255        }
 256
 257        /* Return memory from the excess pool to that pool */
 258        if (excess_freed)
 259                vio_cmo.excess.free += excess_freed;
 260
 261        if (balance)
 262                schedule_delayed_work(&vio_cmo.balance_q, VIO_CMO_BALANCE_DELAY);
 263        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 264}
 265
 266/**
 267 * vio_cmo_entitlement_update - Manage system entitlement changes
 268 *
 269 * @new_entitlement: new system entitlement to attempt to accommodate
 270 *
 271 * Increases in entitlement will be used to fulfill the spare entitlement
 272 * and the rest is given to the excess pool.  Decreases, if they are
 273 * possible, come from the excess pool and from unused device entitlement
 274 *
 275 * Returns: 0 on success, -ENOMEM when change can not be made
 276 */
 277int vio_cmo_entitlement_update(size_t new_entitlement)
 278{
 279        struct vio_dev *viodev;
 280        struct vio_cmo_dev_entry *dev_ent;
 281        unsigned long flags;
 282        size_t avail, delta, tmp;
 283
 284        spin_lock_irqsave(&vio_cmo.lock, flags);
 285
 286        /* Entitlement increases */
 287        if (new_entitlement > vio_cmo.entitled) {
 288                delta = new_entitlement - vio_cmo.entitled;
 289
 290                /* Fulfill spare allocation */
 291                if (vio_cmo.spare < VIO_CMO_MIN_ENT) {
 292                        tmp = min(delta, (VIO_CMO_MIN_ENT - vio_cmo.spare));
 293                        vio_cmo.spare += tmp;
 294                        vio_cmo.reserve.size += tmp;
 295                        delta -= tmp;
 296                }
 297
 298                /* Remaining new allocation goes to the excess pool */
 299                vio_cmo.entitled += delta;
 300                vio_cmo.excess.size += delta;
 301                vio_cmo.excess.free += delta;
 302
 303                goto out;
 304        }
 305
 306        /* Entitlement decreases */
 307        delta = vio_cmo.entitled - new_entitlement;
 308        avail = vio_cmo.excess.free;
 309
 310        /*
 311         * Need to check how much unused entitlement each device can
 312         * sacrifice to fulfill entitlement change.
 313         */
 314        list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 315                if (avail >= delta)
 316                        break;
 317
 318                viodev = dev_ent->viodev;
 319                if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
 320                    (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
 321                                avail += viodev->cmo.entitled -
 322                                         max_t(size_t, viodev->cmo.allocated,
 323                                               VIO_CMO_MIN_ENT);
 324        }
 325
 326        if (delta <= avail) {
 327                vio_cmo.entitled -= delta;
 328
 329                /* Take entitlement from the excess pool first */
 330                tmp = min(vio_cmo.excess.free, delta);
 331                vio_cmo.excess.size -= tmp;
 332                vio_cmo.excess.free -= tmp;
 333                delta -= tmp;
 334
 335                /*
 336                 * Remove all but VIO_CMO_MIN_ENT bytes from devices
 337                 * until entitlement change is served
 338                 */
 339                list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 340                        if (!delta)
 341                                break;
 342
 343                        viodev = dev_ent->viodev;
 344                        tmp = 0;
 345                        if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
 346                            (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
 347                                tmp = viodev->cmo.entitled -
 348                                      max_t(size_t, viodev->cmo.allocated,
 349                                            VIO_CMO_MIN_ENT);
 350                        viodev->cmo.entitled -= min(tmp, delta);
 351                        delta -= min(tmp, delta);
 352                }
 353        } else {
 354                spin_unlock_irqrestore(&vio_cmo.lock, flags);
 355                return -ENOMEM;
 356        }
 357
 358out:
 359        schedule_delayed_work(&vio_cmo.balance_q, 0);
 360        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 361        return 0;
 362}
 363
 364/**
 365 * vio_cmo_balance - Balance entitlement among devices
 366 *
 367 * @work: work queue structure for this operation
 368 *
 369 * Any system entitlement above the minimum needed for devices, or
 370 * already allocated to devices, can be distributed to the devices.
 371 * The list of devices is iterated through to recalculate the desired
 372 * entitlement level and to determine how much entitlement above the
 373 * minimum entitlement is allocated to devices.
 374 *
 375 * Small chunks of the available entitlement are given to devices until
 376 * their requirements are fulfilled or there is no entitlement left to give.
 377 * Upon completion sizes of the reserve and excess pools are calculated.
 378 *
 379 * The system minimum entitlement level is also recalculated here.
 380 * Entitlement will be reserved for devices even after vio_bus_remove to
 381 * accommodate reloading the driver.  The OF tree is walked to count the
 382 * number of devices present and this will remove entitlement for devices
 383 * that have actually left the system after having vio_bus_remove called.
 384 */
 385static void vio_cmo_balance(struct work_struct *work)
 386{
 387        struct vio_cmo *cmo;
 388        struct vio_dev *viodev;
 389        struct vio_cmo_dev_entry *dev_ent;
 390        unsigned long flags;
 391        size_t avail = 0, level, chunk, need;
 392        int devcount = 0, fulfilled;
 393
 394        cmo = container_of(work, struct vio_cmo, balance_q.work);
 395
 396        spin_lock_irqsave(&vio_cmo.lock, flags);
 397
 398        /* Calculate minimum entitlement and fulfill spare */
 399        cmo->min = vio_cmo_num_OF_devs() * VIO_CMO_MIN_ENT;
 400        BUG_ON(cmo->min > cmo->entitled);
 401        cmo->spare = min_t(size_t, VIO_CMO_MIN_ENT, (cmo->entitled - cmo->min));
 402        cmo->min += cmo->spare;
 403        cmo->desired = cmo->min;
 404
 405        /*
 406         * Determine how much entitlement is available and reset device
 407         * entitlements
 408         */
 409        avail = cmo->entitled - cmo->spare;
 410        list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 411                viodev = dev_ent->viodev;
 412                devcount++;
 413                viodev->cmo.entitled = VIO_CMO_MIN_ENT;
 414                cmo->desired += (viodev->cmo.desired - VIO_CMO_MIN_ENT);
 415                avail -= max_t(size_t, viodev->cmo.allocated, VIO_CMO_MIN_ENT);
 416        }
 417
 418        /*
 419         * Having provided each device with the minimum entitlement, loop
 420         * over the devices portioning out the remaining entitlement
 421         * until there is nothing left.
 422         */
 423        level = VIO_CMO_MIN_ENT;
 424        while (avail) {
 425                fulfilled = 0;
 426                list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 427                        viodev = dev_ent->viodev;
 428
 429                        if (viodev->cmo.desired <= level) {
 430                                fulfilled++;
 431                                continue;
 432                        }
 433
 434                        /*
 435                         * Give the device up to VIO_CMO_BALANCE_CHUNK
 436                         * bytes of entitlement, but do not exceed the
 437                         * desired level of entitlement for the device.
 438                         */
 439                        chunk = min_t(size_t, avail, VIO_CMO_BALANCE_CHUNK);
 440                        chunk = min(chunk, (viodev->cmo.desired -
 441                                            viodev->cmo.entitled));
 442                        viodev->cmo.entitled += chunk;
 443
 444                        /*
 445                         * If the memory for this entitlement increase was
 446                         * already allocated to the device it does not come
 447                         * from the available pool being portioned out.
 448                         */
 449                        need = max(viodev->cmo.allocated, viodev->cmo.entitled)-
 450                               max(viodev->cmo.allocated, level);
 451                        avail -= need;
 452
 453                }
 454                if (fulfilled == devcount)
 455                        break;
 456                level += VIO_CMO_BALANCE_CHUNK;
 457        }
 458
 459        /* Calculate new reserve and excess pool sizes */
 460        cmo->reserve.size = cmo->min;
 461        cmo->excess.free = 0;
 462        cmo->excess.size = 0;
 463        need = 0;
 464        list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
 465                viodev = dev_ent->viodev;
 466                /* Calculated reserve size above the minimum entitlement */
 467                if (viodev->cmo.entitled)
 468                        cmo->reserve.size += (viodev->cmo.entitled -
 469                                              VIO_CMO_MIN_ENT);
 470                /* Calculated used excess entitlement */
 471                if (viodev->cmo.allocated > viodev->cmo.entitled)
 472                        need += viodev->cmo.allocated - viodev->cmo.entitled;
 473        }
 474        cmo->excess.size = cmo->entitled - cmo->reserve.size;
 475        cmo->excess.free = cmo->excess.size - need;
 476
 477        cancel_delayed_work(to_delayed_work(work));
 478        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 479}
 480
 481static void *vio_dma_iommu_alloc_coherent(struct device *dev, size_t size,
 482                                          dma_addr_t *dma_handle, gfp_t flag,
 483                                          unsigned long attrs)
 484{
 485        struct vio_dev *viodev = to_vio_dev(dev);
 486        void *ret;
 487
 488        if (vio_cmo_alloc(viodev, roundup(size, PAGE_SIZE))) {
 489                atomic_inc(&viodev->cmo.allocs_failed);
 490                return NULL;
 491        }
 492
 493        ret = iommu_alloc_coherent(dev, get_iommu_table_base(dev), size,
 494                                    dma_handle, dev->coherent_dma_mask, flag,
 495                                    dev_to_node(dev));
 496        if (unlikely(ret == NULL)) {
 497                vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
 498                atomic_inc(&viodev->cmo.allocs_failed);
 499        }
 500
 501        return ret;
 502}
 503
 504static void vio_dma_iommu_free_coherent(struct device *dev, size_t size,
 505                                        void *vaddr, dma_addr_t dma_handle,
 506                                        unsigned long attrs)
 507{
 508        struct vio_dev *viodev = to_vio_dev(dev);
 509
 510        iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle);
 511        vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
 512}
 513
 514static dma_addr_t vio_dma_iommu_map_page(struct device *dev, struct page *page,
 515                                         unsigned long offset, size_t size,
 516                                         enum dma_data_direction direction,
 517                                         unsigned long attrs)
 518{
 519        struct vio_dev *viodev = to_vio_dev(dev);
 520        struct iommu_table *tbl = get_iommu_table_base(dev);
 521        dma_addr_t ret = DMA_MAPPING_ERROR;
 522
 523        if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl))))
 524                goto out_fail;
 525        ret = iommu_map_page(dev, tbl, page, offset, size, dma_get_mask(dev),
 526                        direction, attrs);
 527        if (unlikely(ret == DMA_MAPPING_ERROR))
 528                goto out_deallocate;
 529        return ret;
 530
 531out_deallocate:
 532        vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
 533out_fail:
 534        atomic_inc(&viodev->cmo.allocs_failed);
 535        return DMA_MAPPING_ERROR;
 536}
 537
 538static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
 539                                     size_t size,
 540                                     enum dma_data_direction direction,
 541                                     unsigned long attrs)
 542{
 543        struct vio_dev *viodev = to_vio_dev(dev);
 544        struct iommu_table *tbl = get_iommu_table_base(dev);
 545
 546        iommu_unmap_page(tbl, dma_handle, size, direction, attrs);
 547        vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
 548}
 549
 550static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
 551                                int nelems, enum dma_data_direction direction,
 552                                unsigned long attrs)
 553{
 554        struct vio_dev *viodev = to_vio_dev(dev);
 555        struct iommu_table *tbl = get_iommu_table_base(dev);
 556        struct scatterlist *sgl;
 557        int ret, count;
 558        size_t alloc_size = 0;
 559
 560        for_each_sg(sglist, sgl, nelems, count)
 561                alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE(tbl));
 562
 563        if (vio_cmo_alloc(viodev, alloc_size))
 564                goto out_fail;
 565        ret = ppc_iommu_map_sg(dev, tbl, sglist, nelems, dma_get_mask(dev),
 566                        direction, attrs);
 567        if (unlikely(!ret))
 568                goto out_deallocate;
 569
 570        for_each_sg(sglist, sgl, ret, count)
 571                alloc_size -= roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
 572        if (alloc_size)
 573                vio_cmo_dealloc(viodev, alloc_size);
 574        return ret;
 575
 576out_deallocate:
 577        vio_cmo_dealloc(viodev, alloc_size);
 578out_fail:
 579        atomic_inc(&viodev->cmo.allocs_failed);
 580        return 0;
 581}
 582
 583static void vio_dma_iommu_unmap_sg(struct device *dev,
 584                struct scatterlist *sglist, int nelems,
 585                enum dma_data_direction direction,
 586                unsigned long attrs)
 587{
 588        struct vio_dev *viodev = to_vio_dev(dev);
 589        struct iommu_table *tbl = get_iommu_table_base(dev);
 590        struct scatterlist *sgl;
 591        size_t alloc_size = 0;
 592        int count;
 593
 594        for_each_sg(sglist, sgl, nelems, count)
 595                alloc_size += roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
 596
 597        ppc_iommu_unmap_sg(tbl, sglist, nelems, direction, attrs);
 598        vio_cmo_dealloc(viodev, alloc_size);
 599}
 600
 601static const struct dma_map_ops vio_dma_mapping_ops = {
 602        .alloc             = vio_dma_iommu_alloc_coherent,
 603        .free              = vio_dma_iommu_free_coherent,
 604        .map_sg            = vio_dma_iommu_map_sg,
 605        .unmap_sg          = vio_dma_iommu_unmap_sg,
 606        .map_page          = vio_dma_iommu_map_page,
 607        .unmap_page        = vio_dma_iommu_unmap_page,
 608        .dma_supported     = dma_iommu_dma_supported,
 609        .get_required_mask = dma_iommu_get_required_mask,
 610        .mmap              = dma_common_mmap,
 611        .get_sgtable       = dma_common_get_sgtable,
 612        .alloc_pages       = dma_common_alloc_pages,
 613        .free_pages        = dma_common_free_pages,
 614};
 615
 616/**
 617 * vio_cmo_set_dev_desired - Set desired entitlement for a device
 618 *
 619 * @viodev: struct vio_dev for device to alter
 620 * @desired: new desired entitlement level in bytes
 621 *
 622 * For use by devices to request a change to their entitlement at runtime or
 623 * through sysfs.  The desired entitlement level is changed and a balancing
 624 * of system resources is scheduled to run in the future.
 625 */
 626void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired)
 627{
 628        unsigned long flags;
 629        struct vio_cmo_dev_entry *dev_ent;
 630        int found = 0;
 631
 632        if (!firmware_has_feature(FW_FEATURE_CMO))
 633                return;
 634
 635        spin_lock_irqsave(&vio_cmo.lock, flags);
 636        if (desired < VIO_CMO_MIN_ENT)
 637                desired = VIO_CMO_MIN_ENT;
 638
 639        /*
 640         * Changes will not be made for devices not in the device list.
 641         * If it is not in the device list, then no driver is loaded
 642         * for the device and it can not receive entitlement.
 643         */
 644        list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
 645                if (viodev == dev_ent->viodev) {
 646                        found = 1;
 647                        break;
 648                }
 649        if (!found) {
 650                spin_unlock_irqrestore(&vio_cmo.lock, flags);
 651                return;
 652        }
 653
 654        /* Increase/decrease in desired device entitlement */
 655        if (desired >= viodev->cmo.desired) {
 656                /* Just bump the bus and device values prior to a balance*/
 657                vio_cmo.desired += desired - viodev->cmo.desired;
 658                viodev->cmo.desired = desired;
 659        } else {
 660                /* Decrease bus and device values for desired entitlement */
 661                vio_cmo.desired -= viodev->cmo.desired - desired;
 662                viodev->cmo.desired = desired;
 663                /*
 664                 * If less entitlement is desired than current entitlement, move
 665                 * any reserve memory in the change region to the excess pool.
 666                 */
 667                if (viodev->cmo.entitled > desired) {
 668                        vio_cmo.reserve.size -= viodev->cmo.entitled - desired;
 669                        vio_cmo.excess.size += viodev->cmo.entitled - desired;
 670                        /*
 671                         * If entitlement moving from the reserve pool to the
 672                         * excess pool is currently unused, add to the excess
 673                         * free counter.
 674                         */
 675                        if (viodev->cmo.allocated < viodev->cmo.entitled)
 676                                vio_cmo.excess.free += viodev->cmo.entitled -
 677                                                       max(viodev->cmo.allocated, desired);
 678                        viodev->cmo.entitled = desired;
 679                }
 680        }
 681        schedule_delayed_work(&vio_cmo.balance_q, 0);
 682        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 683}
 684
 685/**
 686 * vio_cmo_bus_probe - Handle CMO specific bus probe activities
 687 *
 688 * @viodev - Pointer to struct vio_dev for device
 689 *
 690 * Determine the devices IO memory entitlement needs, attempting
 691 * to satisfy the system minimum entitlement at first and scheduling
 692 * a balance operation to take care of the rest at a later time.
 693 *
 694 * Returns: 0 on success, -EINVAL when device doesn't support CMO, and
 695 *          -ENOMEM when entitlement is not available for device or
 696 *          device entry.
 697 *
 698 */
 699static int vio_cmo_bus_probe(struct vio_dev *viodev)
 700{
 701        struct vio_cmo_dev_entry *dev_ent;
 702        struct device *dev = &viodev->dev;
 703        struct iommu_table *tbl;
 704        struct vio_driver *viodrv = to_vio_driver(dev->driver);
 705        unsigned long flags;
 706        size_t size;
 707        bool dma_capable = false;
 708
 709        tbl = get_iommu_table_base(dev);
 710
 711        /* A device requires entitlement if it has a DMA window property */
 712        switch (viodev->family) {
 713        case VDEVICE:
 714                if (of_get_property(viodev->dev.of_node,
 715                                        "ibm,my-dma-window", NULL))
 716                        dma_capable = true;
 717                break;
 718        case PFO:
 719                dma_capable = false;
 720                break;
 721        default:
 722                dev_warn(dev, "unknown device family: %d\n", viodev->family);
 723                BUG();
 724                break;
 725        }
 726
 727        /* Configure entitlement for the device. */
 728        if (dma_capable) {
 729                /* Check that the driver is CMO enabled and get desired DMA */
 730                if (!viodrv->get_desired_dma) {
 731                        dev_err(dev, "%s: device driver does not support CMO\n",
 732                                __func__);
 733                        return -EINVAL;
 734                }
 735
 736                viodev->cmo.desired =
 737                        IOMMU_PAGE_ALIGN(viodrv->get_desired_dma(viodev), tbl);
 738                if (viodev->cmo.desired < VIO_CMO_MIN_ENT)
 739                        viodev->cmo.desired = VIO_CMO_MIN_ENT;
 740                size = VIO_CMO_MIN_ENT;
 741
 742                dev_ent = kmalloc(sizeof(struct vio_cmo_dev_entry),
 743                                  GFP_KERNEL);
 744                if (!dev_ent)
 745                        return -ENOMEM;
 746
 747                dev_ent->viodev = viodev;
 748                spin_lock_irqsave(&vio_cmo.lock, flags);
 749                list_add(&dev_ent->list, &vio_cmo.device_list);
 750        } else {
 751                viodev->cmo.desired = 0;
 752                size = 0;
 753                spin_lock_irqsave(&vio_cmo.lock, flags);
 754        }
 755
 756        /*
 757         * If the needs for vio_cmo.min have not changed since they
 758         * were last set, the number of devices in the OF tree has
 759         * been constant and the IO memory for this is already in
 760         * the reserve pool.
 761         */
 762        if (vio_cmo.min == ((vio_cmo_num_OF_devs() + 1) *
 763                            VIO_CMO_MIN_ENT)) {
 764                /* Updated desired entitlement if device requires it */
 765                if (size)
 766                        vio_cmo.desired += (viodev->cmo.desired -
 767                                        VIO_CMO_MIN_ENT);
 768        } else {
 769                size_t tmp;
 770
 771                tmp = vio_cmo.spare + vio_cmo.excess.free;
 772                if (tmp < size) {
 773                        dev_err(dev, "%s: insufficient free "
 774                                "entitlement to add device. "
 775                                "Need %lu, have %lu\n", __func__,
 776                                size, (vio_cmo.spare + tmp));
 777                        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 778                        return -ENOMEM;
 779                }
 780
 781                /* Use excess pool first to fulfill request */
 782                tmp = min(size, vio_cmo.excess.free);
 783                vio_cmo.excess.free -= tmp;
 784                vio_cmo.excess.size -= tmp;
 785                vio_cmo.reserve.size += tmp;
 786
 787                /* Use spare if excess pool was insufficient */
 788                vio_cmo.spare -= size - tmp;
 789
 790                /* Update bus accounting */
 791                vio_cmo.min += size;
 792                vio_cmo.desired += viodev->cmo.desired;
 793        }
 794        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 795        return 0;
 796}
 797
 798/**
 799 * vio_cmo_bus_remove - Handle CMO specific bus removal activities
 800 *
 801 * @viodev - Pointer to struct vio_dev for device
 802 *
 803 * Remove the device from the cmo device list.  The minimum entitlement
 804 * will be reserved for the device as long as it is in the system.  The
 805 * rest of the entitlement the device had been allocated will be returned
 806 * to the system.
 807 */
 808static void vio_cmo_bus_remove(struct vio_dev *viodev)
 809{
 810        struct vio_cmo_dev_entry *dev_ent;
 811        unsigned long flags;
 812        size_t tmp;
 813
 814        spin_lock_irqsave(&vio_cmo.lock, flags);
 815        if (viodev->cmo.allocated) {
 816                dev_err(&viodev->dev, "%s: device had %lu bytes of IO "
 817                        "allocated after remove operation.\n",
 818                        __func__, viodev->cmo.allocated);
 819                BUG();
 820        }
 821
 822        /*
 823         * Remove the device from the device list being maintained for
 824         * CMO enabled devices.
 825         */
 826        list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
 827                if (viodev == dev_ent->viodev) {
 828                        list_del(&dev_ent->list);
 829                        kfree(dev_ent);
 830                        break;
 831                }
 832
 833        /*
 834         * Devices may not require any entitlement and they do not need
 835         * to be processed.  Otherwise, return the device's entitlement
 836         * back to the pools.
 837         */
 838        if (viodev->cmo.entitled) {
 839                /*
 840                 * This device has not yet left the OF tree, it's
 841                 * minimum entitlement remains in vio_cmo.min and
 842                 * vio_cmo.desired
 843                 */
 844                vio_cmo.desired -= (viodev->cmo.desired - VIO_CMO_MIN_ENT);
 845
 846                /*
 847                 * Save min allocation for device in reserve as long
 848                 * as it exists in OF tree as determined by later
 849                 * balance operation
 850                 */
 851                viodev->cmo.entitled -= VIO_CMO_MIN_ENT;
 852
 853                /* Replenish spare from freed reserve pool */
 854                if (viodev->cmo.entitled && (vio_cmo.spare < VIO_CMO_MIN_ENT)) {
 855                        tmp = min(viodev->cmo.entitled, (VIO_CMO_MIN_ENT -
 856                                                         vio_cmo.spare));
 857                        vio_cmo.spare += tmp;
 858                        viodev->cmo.entitled -= tmp;
 859                }
 860
 861                /* Remaining reserve goes to excess pool */
 862                vio_cmo.excess.size += viodev->cmo.entitled;
 863                vio_cmo.excess.free += viodev->cmo.entitled;
 864                vio_cmo.reserve.size -= viodev->cmo.entitled;
 865
 866                /*
 867                 * Until the device is removed it will keep a
 868                 * minimum entitlement; this will guarantee that
 869                 * a module unload/load will result in a success.
 870                 */
 871                viodev->cmo.entitled = VIO_CMO_MIN_ENT;
 872                viodev->cmo.desired = VIO_CMO_MIN_ENT;
 873                atomic_set(&viodev->cmo.allocs_failed, 0);
 874        }
 875
 876        spin_unlock_irqrestore(&vio_cmo.lock, flags);
 877}
 878
 879static void vio_cmo_set_dma_ops(struct vio_dev *viodev)
 880{
 881        set_dma_ops(&viodev->dev, &vio_dma_mapping_ops);
 882}
 883
 884/**
 885 * vio_cmo_bus_init - CMO entitlement initialization at bus init time
 886 *
 887 * Set up the reserve and excess entitlement pools based on available
 888 * system entitlement and the number of devices in the OF tree that
 889 * require entitlement in the reserve pool.
 890 */
 891static void vio_cmo_bus_init(void)
 892{
 893        struct hvcall_mpp_data mpp_data;
 894        int err;
 895
 896        memset(&vio_cmo, 0, sizeof(struct vio_cmo));
 897        spin_lock_init(&vio_cmo.lock);
 898        INIT_LIST_HEAD(&vio_cmo.device_list);
 899        INIT_DELAYED_WORK(&vio_cmo.balance_q, vio_cmo_balance);
 900
 901        /* Get current system entitlement */
 902        err = h_get_mpp(&mpp_data);
 903
 904        /*
 905         * On failure, continue with entitlement set to 0, will panic()
 906         * later when spare is reserved.
 907         */
 908        if (err != H_SUCCESS) {
 909                printk(KERN_ERR "%s: unable to determine system IO "\
 910                       "entitlement. (%d)\n", __func__, err);
 911                vio_cmo.entitled = 0;
 912        } else {
 913                vio_cmo.entitled = mpp_data.entitled_mem;
 914        }
 915
 916        /* Set reservation and check against entitlement */
 917        vio_cmo.spare = VIO_CMO_MIN_ENT;
 918        vio_cmo.reserve.size = vio_cmo.spare;
 919        vio_cmo.reserve.size += (vio_cmo_num_OF_devs() *
 920                                 VIO_CMO_MIN_ENT);
 921        if (vio_cmo.reserve.size > vio_cmo.entitled) {
 922                printk(KERN_ERR "%s: insufficient system entitlement\n",
 923                       __func__);
 924                panic("%s: Insufficient system entitlement", __func__);
 925        }
 926
 927        /* Set the remaining accounting variables */
 928        vio_cmo.excess.size = vio_cmo.entitled - vio_cmo.reserve.size;
 929        vio_cmo.excess.free = vio_cmo.excess.size;
 930        vio_cmo.min = vio_cmo.reserve.size;
 931        vio_cmo.desired = vio_cmo.reserve.size;
 932}
 933
 934/* sysfs device functions and data structures for CMO */
 935
 936#define viodev_cmo_rd_attr(name)                                        \
 937static ssize_t cmo_##name##_show(struct device *dev,                    \
 938                                        struct device_attribute *attr,  \
 939                                         char *buf)                     \
 940{                                                                       \
 941        return sprintf(buf, "%lu\n", to_vio_dev(dev)->cmo.name);        \
 942}
 943
 944static ssize_t cmo_allocs_failed_show(struct device *dev,
 945                struct device_attribute *attr, char *buf)
 946{
 947        struct vio_dev *viodev = to_vio_dev(dev);
 948        return sprintf(buf, "%d\n", atomic_read(&viodev->cmo.allocs_failed));
 949}
 950
 951static ssize_t cmo_allocs_failed_store(struct device *dev,
 952                struct device_attribute *attr, const char *buf, size_t count)
 953{
 954        struct vio_dev *viodev = to_vio_dev(dev);
 955        atomic_set(&viodev->cmo.allocs_failed, 0);
 956        return count;
 957}
 958
 959static ssize_t cmo_desired_store(struct device *dev,
 960                struct device_attribute *attr, const char *buf, size_t count)
 961{
 962        struct vio_dev *viodev = to_vio_dev(dev);
 963        size_t new_desired;
 964        int ret;
 965
 966        ret = kstrtoul(buf, 10, &new_desired);
 967        if (ret)
 968                return ret;
 969
 970        vio_cmo_set_dev_desired(viodev, new_desired);
 971        return count;
 972}
 973
 974viodev_cmo_rd_attr(desired);
 975viodev_cmo_rd_attr(entitled);
 976viodev_cmo_rd_attr(allocated);
 977
 978static ssize_t name_show(struct device *, struct device_attribute *, char *);
 979static ssize_t devspec_show(struct device *, struct device_attribute *, char *);
 980static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 981                             char *buf);
 982
 983static struct device_attribute dev_attr_name;
 984static struct device_attribute dev_attr_devspec;
 985static struct device_attribute dev_attr_modalias;
 986
 987static DEVICE_ATTR_RO(cmo_entitled);
 988static DEVICE_ATTR_RO(cmo_allocated);
 989static DEVICE_ATTR_RW(cmo_desired);
 990static DEVICE_ATTR_RW(cmo_allocs_failed);
 991
 992static struct attribute *vio_cmo_dev_attrs[] = {
 993        &dev_attr_name.attr,
 994        &dev_attr_devspec.attr,
 995        &dev_attr_modalias.attr,
 996        &dev_attr_cmo_entitled.attr,
 997        &dev_attr_cmo_allocated.attr,
 998        &dev_attr_cmo_desired.attr,
 999        &dev_attr_cmo_allocs_failed.attr,
1000        NULL,
1001};
1002ATTRIBUTE_GROUPS(vio_cmo_dev);
1003
1004/* sysfs bus functions and data structures for CMO */
1005
1006#define viobus_cmo_rd_attr(name)                                        \
1007static ssize_t cmo_bus_##name##_show(struct bus_type *bt, char *buf)    \
1008{                                                                       \
1009        return sprintf(buf, "%lu\n", vio_cmo.name);                     \
1010}                                                                       \
1011static struct bus_attribute bus_attr_cmo_bus_##name =                   \
1012        __ATTR(cmo_##name, S_IRUGO, cmo_bus_##name##_show, NULL)
1013
1014#define viobus_cmo_pool_rd_attr(name, var)                              \
1015static ssize_t                                                          \
1016cmo_##name##_##var##_show(struct bus_type *bt, char *buf)               \
1017{                                                                       \
1018        return sprintf(buf, "%lu\n", vio_cmo.name.var);                 \
1019}                                                                       \
1020static BUS_ATTR_RO(cmo_##name##_##var)
1021
1022viobus_cmo_rd_attr(entitled);
1023viobus_cmo_rd_attr(spare);
1024viobus_cmo_rd_attr(min);
1025viobus_cmo_rd_attr(desired);
1026viobus_cmo_rd_attr(curr);
1027viobus_cmo_pool_rd_attr(reserve, size);
1028viobus_cmo_pool_rd_attr(excess, size);
1029viobus_cmo_pool_rd_attr(excess, free);
1030
1031static ssize_t cmo_high_show(struct bus_type *bt, char *buf)
1032{
1033        return sprintf(buf, "%lu\n", vio_cmo.high);
1034}
1035
1036static ssize_t cmo_high_store(struct bus_type *bt, const char *buf,
1037                              size_t count)
1038{
1039        unsigned long flags;
1040
1041        spin_lock_irqsave(&vio_cmo.lock, flags);
1042        vio_cmo.high = vio_cmo.curr;
1043        spin_unlock_irqrestore(&vio_cmo.lock, flags);
1044
1045        return count;
1046}
1047static BUS_ATTR_RW(cmo_high);
1048
1049static struct attribute *vio_bus_attrs[] = {
1050        &bus_attr_cmo_bus_entitled.attr,
1051        &bus_attr_cmo_bus_spare.attr,
1052        &bus_attr_cmo_bus_min.attr,
1053        &bus_attr_cmo_bus_desired.attr,
1054        &bus_attr_cmo_bus_curr.attr,
1055        &bus_attr_cmo_high.attr,
1056        &bus_attr_cmo_reserve_size.attr,
1057        &bus_attr_cmo_excess_size.attr,
1058        &bus_attr_cmo_excess_free.attr,
1059        NULL,
1060};
1061ATTRIBUTE_GROUPS(vio_bus);
1062
1063static void vio_cmo_sysfs_init(void)
1064{
1065        vio_bus_type.dev_groups = vio_cmo_dev_groups;
1066        vio_bus_type.bus_groups = vio_bus_groups;
1067}
1068#else /* CONFIG_PPC_SMLPAR */
1069int vio_cmo_entitlement_update(size_t new_entitlement) { return 0; }
1070void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired) {}
1071static int vio_cmo_bus_probe(struct vio_dev *viodev) { return 0; }
1072static void vio_cmo_bus_remove(struct vio_dev *viodev) {}
1073static void vio_cmo_set_dma_ops(struct vio_dev *viodev) {}
1074static void vio_cmo_bus_init(void) {}
1075static void vio_cmo_sysfs_init(void) { }
1076#endif /* CONFIG_PPC_SMLPAR */
1077EXPORT_SYMBOL(vio_cmo_entitlement_update);
1078EXPORT_SYMBOL(vio_cmo_set_dev_desired);
1079
1080
1081/*
1082 * Platform Facilities Option (PFO) support
1083 */
1084
1085/**
1086 * vio_h_cop_sync - Perform a synchronous PFO co-processor operation
1087 *
1088 * @vdev - Pointer to a struct vio_dev for device
1089 * @op - Pointer to a struct vio_pfo_op for the operation parameters
1090 *
1091 * Calls the hypervisor to synchronously perform the PFO operation
1092 * described in @op.  In the case of a busy response from the hypervisor,
1093 * the operation will be re-submitted indefinitely unless a non-zero timeout
1094 * is specified or an error occurs. The timeout places a limit on when to
1095 * stop re-submitting a operation, the total time can be exceeded if an
1096 * operation is in progress.
1097 *
1098 * If op->hcall_ret is not NULL, this will be set to the return from the
1099 * last h_cop_op call or it will be 0 if an error not involving the h_call
1100 * was encountered.
1101 *
1102 * Returns:
1103 *      0 on success,
1104 *      -EINVAL if the h_call fails due to an invalid parameter,
1105 *      -E2BIG if the h_call can not be performed synchronously,
1106 *      -EBUSY if a timeout is specified and has elapsed,
1107 *      -EACCES if the memory area for data/status has been rescinded, or
1108 *      -EPERM if a hardware fault has been indicated
1109 */
1110int vio_h_cop_sync(struct vio_dev *vdev, struct vio_pfo_op *op)
1111{
1112        struct device *dev = &vdev->dev;
1113        unsigned long deadline = 0;
1114        long hret = 0;
1115        int ret = 0;
1116
1117        if (op->timeout)
1118                deadline = jiffies + msecs_to_jiffies(op->timeout);
1119
1120        while (true) {
1121                hret = plpar_hcall_norets(H_COP, op->flags,
1122                                vdev->resource_id,
1123                                op->in, op->inlen, op->out,
1124                                op->outlen, op->csbcpb);
1125
1126                if (hret == H_SUCCESS ||
1127                    (hret != H_NOT_ENOUGH_RESOURCES &&
1128                     hret != H_BUSY && hret != H_RESOURCE) ||
1129                    (op->timeout && time_after(deadline, jiffies)))
1130                        break;
1131
1132                dev_dbg(dev, "%s: hcall ret(%ld), retrying.\n", __func__, hret);
1133        }
1134
1135        switch (hret) {
1136        case H_SUCCESS:
1137                ret = 0;
1138                break;
1139        case H_OP_MODE:
1140        case H_TOO_BIG:
1141                ret = -E2BIG;
1142                break;
1143        case H_RESCINDED:
1144                ret = -EACCES;
1145                break;
1146        case H_HARDWARE:
1147                ret = -EPERM;
1148                break;
1149        case H_NOT_ENOUGH_RESOURCES:
1150        case H_RESOURCE:
1151        case H_BUSY:
1152                ret = -EBUSY;
1153                break;
1154        default:
1155                ret = -EINVAL;
1156                break;
1157        }
1158
1159        if (ret)
1160                dev_dbg(dev, "%s: Sync h_cop_op failure (ret:%d) (hret:%ld)\n",
1161                                __func__, ret, hret);
1162
1163        op->hcall_err = hret;
1164        return ret;
1165}
1166EXPORT_SYMBOL(vio_h_cop_sync);
1167
1168static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
1169{
1170        const __be32 *dma_window;
1171        struct iommu_table *tbl;
1172        unsigned long offset, size;
1173
1174        dma_window = of_get_property(dev->dev.of_node,
1175                                  "ibm,my-dma-window", NULL);
1176        if (!dma_window)
1177                return NULL;
1178
1179        tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
1180        if (tbl == NULL)
1181                return NULL;
1182
1183        kref_init(&tbl->it_kref);
1184
1185        of_parse_dma_window(dev->dev.of_node, dma_window,
1186                            &tbl->it_index, &offset, &size);
1187
1188        /* TCE table size - measured in tce entries */
1189        tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
1190        tbl->it_size = size >> tbl->it_page_shift;
1191        /* offset for VIO should always be 0 */
1192        tbl->it_offset = offset >> tbl->it_page_shift;
1193        tbl->it_busno = 0;
1194        tbl->it_type = TCE_VB;
1195        tbl->it_blocksize = 16;
1196
1197        if (firmware_has_feature(FW_FEATURE_LPAR))
1198                tbl->it_ops = &iommu_table_lpar_multi_ops;
1199        else
1200                tbl->it_ops = &iommu_table_pseries_ops;
1201
1202        return iommu_init_table(tbl, -1, 0, 0);
1203}
1204
1205/**
1206 * vio_match_device: - Tell if a VIO device has a matching
1207 *                      VIO device id structure.
1208 * @ids:        array of VIO device id structures to search in
1209 * @dev:        the VIO device structure to match against
1210 *
1211 * Used by a driver to check whether a VIO device present in the
1212 * system is in its list of supported devices. Returns the matching
1213 * vio_device_id structure or NULL if there is no match.
1214 */
1215static const struct vio_device_id *vio_match_device(
1216                const struct vio_device_id *ids, const struct vio_dev *dev)
1217{
1218        while (ids->type[0] != '\0') {
1219                if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
1220                    of_device_is_compatible(dev->dev.of_node,
1221                                         ids->compat))
1222                        return ids;
1223                ids++;
1224        }
1225        return NULL;
1226}
1227
1228/*
1229 * Convert from struct device to struct vio_dev and pass to driver.
1230 * dev->driver has already been set by generic code because vio_bus_match
1231 * succeeded.
1232 */
1233static int vio_bus_probe(struct device *dev)
1234{
1235        struct vio_dev *viodev = to_vio_dev(dev);
1236        struct vio_driver *viodrv = to_vio_driver(dev->driver);
1237        const struct vio_device_id *id;
1238        int error = -ENODEV;
1239
1240        if (!viodrv->probe)
1241                return error;
1242
1243        id = vio_match_device(viodrv->id_table, viodev);
1244        if (id) {
1245                memset(&viodev->cmo, 0, sizeof(viodev->cmo));
1246                if (firmware_has_feature(FW_FEATURE_CMO)) {
1247                        error = vio_cmo_bus_probe(viodev);
1248                        if (error)
1249                                return error;
1250                }
1251                error = viodrv->probe(viodev, id);
1252                if (error && firmware_has_feature(FW_FEATURE_CMO))
1253                        vio_cmo_bus_remove(viodev);
1254        }
1255
1256        return error;
1257}
1258
1259/* convert from struct device to struct vio_dev and pass to driver. */
1260static int vio_bus_remove(struct device *dev)
1261{
1262        struct vio_dev *viodev = to_vio_dev(dev);
1263        struct vio_driver *viodrv = to_vio_driver(dev->driver);
1264        struct device *devptr;
1265
1266        /*
1267         * Hold a reference to the device after the remove function is called
1268         * to allow for CMO accounting cleanup for the device.
1269         */
1270        devptr = get_device(dev);
1271
1272        if (viodrv->remove)
1273                viodrv->remove(viodev);
1274
1275        if (firmware_has_feature(FW_FEATURE_CMO))
1276                vio_cmo_bus_remove(viodev);
1277
1278        put_device(devptr);
1279        return 0;
1280}
1281
1282static void vio_bus_shutdown(struct device *dev)
1283{
1284        struct vio_dev *viodev = to_vio_dev(dev);
1285        struct vio_driver *viodrv;
1286
1287        if (dev->driver) {
1288                viodrv = to_vio_driver(dev->driver);
1289                if (viodrv->shutdown)
1290                        viodrv->shutdown(viodev);
1291                else if (kexec_in_progress)
1292                        vio_bus_remove(dev);
1293        }
1294}
1295
1296/**
1297 * vio_register_driver: - Register a new vio driver
1298 * @viodrv:     The vio_driver structure to be registered.
1299 */
1300int __vio_register_driver(struct vio_driver *viodrv, struct module *owner,
1301                          const char *mod_name)
1302{
1303        // vio_bus_type is only initialised for pseries
1304        if (!machine_is(pseries))
1305                return -ENODEV;
1306
1307        pr_debug("%s: driver %s registering\n", __func__, viodrv->name);
1308
1309        /* fill in 'struct driver' fields */
1310        viodrv->driver.name = viodrv->name;
1311        viodrv->driver.pm = viodrv->pm;
1312        viodrv->driver.bus = &vio_bus_type;
1313        viodrv->driver.owner = owner;
1314        viodrv->driver.mod_name = mod_name;
1315
1316        return driver_register(&viodrv->driver);
1317}
1318EXPORT_SYMBOL(__vio_register_driver);
1319
1320/**
1321 * vio_unregister_driver - Remove registration of vio driver.
1322 * @viodrv:     The vio_driver struct to be removed form registration
1323 */
1324void vio_unregister_driver(struct vio_driver *viodrv)
1325{
1326        driver_unregister(&viodrv->driver);
1327}
1328EXPORT_SYMBOL(vio_unregister_driver);
1329
1330/* vio_dev refcount hit 0 */
1331static void vio_dev_release(struct device *dev)
1332{
1333        struct iommu_table *tbl = get_iommu_table_base(dev);
1334
1335        if (tbl)
1336                iommu_tce_table_put(tbl);
1337        of_node_put(dev->of_node);
1338        kfree(to_vio_dev(dev));
1339}
1340
1341/**
1342 * vio_register_device_node: - Register a new vio device.
1343 * @of_node:    The OF node for this device.
1344 *
1345 * Creates and initializes a vio_dev structure from the data in
1346 * of_node and adds it to the list of virtual devices.
1347 * Returns a pointer to the created vio_dev or NULL if node has
1348 * NULL device_type or compatible fields.
1349 */
1350struct vio_dev *vio_register_device_node(struct device_node *of_node)
1351{
1352        struct vio_dev *viodev;
1353        struct device_node *parent_node;
1354        const __be32 *prop;
1355        enum vio_dev_family family;
1356
1357        /*
1358         * Determine if this node is a under the /vdevice node or under the
1359         * /ibm,platform-facilities node.  This decides the device's family.
1360         */
1361        parent_node = of_get_parent(of_node);
1362        if (parent_node) {
1363                if (of_node_is_type(parent_node, "ibm,platform-facilities"))
1364                        family = PFO;
1365                else if (of_node_is_type(parent_node, "vdevice"))
1366                        family = VDEVICE;
1367                else {
1368                        pr_warn("%s: parent(%pOF) of %pOFn not recognized.\n",
1369                                        __func__,
1370                                        parent_node,
1371                                        of_node);
1372                        of_node_put(parent_node);
1373                        return NULL;
1374                }
1375                of_node_put(parent_node);
1376        } else {
1377                pr_warn("%s: could not determine the parent of node %pOFn.\n",
1378                                __func__, of_node);
1379                return NULL;
1380        }
1381
1382        if (family == PFO) {
1383                if (of_get_property(of_node, "interrupt-controller", NULL)) {
1384                        pr_debug("%s: Skipping the interrupt controller %pOFn.\n",
1385                                        __func__, of_node);
1386                        return NULL;
1387                }
1388        }
1389
1390        /* allocate a vio_dev for this node */
1391        viodev = kzalloc(sizeof(struct vio_dev), GFP_KERNEL);
1392        if (viodev == NULL) {
1393                pr_warn("%s: allocation failure for VIO device.\n", __func__);
1394                return NULL;
1395        }
1396
1397        /* we need the 'device_type' property, in order to match with drivers */
1398        viodev->family = family;
1399        if (viodev->family == VDEVICE) {
1400                unsigned int unit_address;
1401
1402                viodev->type = of_node_get_device_type(of_node);
1403                if (!viodev->type) {
1404                        pr_warn("%s: node %pOFn is missing the 'device_type' "
1405                                        "property.\n", __func__, of_node);
1406                        goto out;
1407                }
1408
1409                prop = of_get_property(of_node, "reg", NULL);
1410                if (prop == NULL) {
1411                        pr_warn("%s: node %pOFn missing 'reg'\n",
1412                                        __func__, of_node);
1413                        goto out;
1414                }
1415                unit_address = of_read_number(prop, 1);
1416                dev_set_name(&viodev->dev, "%x", unit_address);
1417                viodev->irq = irq_of_parse_and_map(of_node, 0);
1418                viodev->unit_address = unit_address;
1419        } else {
1420                /* PFO devices need their resource_id for submitting COP_OPs
1421                 * This is an optional field for devices, but is required when
1422                 * performing synchronous ops */
1423                prop = of_get_property(of_node, "ibm,resource-id", NULL);
1424                if (prop != NULL)
1425                        viodev->resource_id = of_read_number(prop, 1);
1426
1427                dev_set_name(&viodev->dev, "%pOFn", of_node);
1428                viodev->type = dev_name(&viodev->dev);
1429                viodev->irq = 0;
1430        }
1431
1432        viodev->name = of_node->name;
1433        viodev->dev.of_node = of_node_get(of_node);
1434
1435        set_dev_node(&viodev->dev, of_node_to_nid(of_node));
1436
1437        /* init generic 'struct device' fields: */
1438        viodev->dev.parent = &vio_bus_device.dev;
1439        viodev->dev.bus = &vio_bus_type;
1440        viodev->dev.release = vio_dev_release;
1441
1442        if (of_get_property(viodev->dev.of_node, "ibm,my-dma-window", NULL)) {
1443                if (firmware_has_feature(FW_FEATURE_CMO))
1444                        vio_cmo_set_dma_ops(viodev);
1445                else
1446                        set_dma_ops(&viodev->dev, &dma_iommu_ops);
1447
1448                set_iommu_table_base(&viodev->dev,
1449                                     vio_build_iommu_table(viodev));
1450
1451                /* needed to ensure proper operation of coherent allocations
1452                 * later, in case driver doesn't set it explicitly */
1453                viodev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
1454                viodev->dev.dma_mask = &viodev->dev.coherent_dma_mask;
1455        }
1456
1457        /* register with generic device framework */
1458        if (device_register(&viodev->dev)) {
1459                printk(KERN_ERR "%s: failed to register device %s\n",
1460                                __func__, dev_name(&viodev->dev));
1461                put_device(&viodev->dev);
1462                return NULL;
1463        }
1464
1465        return viodev;
1466
1467out:    /* Use this exit point for any return prior to device_register */
1468        kfree(viodev);
1469
1470        return NULL;
1471}
1472EXPORT_SYMBOL(vio_register_device_node);
1473
1474/*
1475 * vio_bus_scan_for_devices - Scan OF and register each child device
1476 * @root_name - OF node name for the root of the subtree to search.
1477 *              This must be non-NULL
1478 *
1479 * Starting from the root node provide, register the device node for
1480 * each child beneath the root.
1481 */
1482static void vio_bus_scan_register_devices(char *root_name)
1483{
1484        struct device_node *node_root, *node_child;
1485
1486        if (!root_name)
1487                return;
1488
1489        node_root = of_find_node_by_name(NULL, root_name);
1490        if (node_root) {
1491
1492                /*
1493                 * Create struct vio_devices for each virtual device in
1494                 * the device tree. Drivers will associate with them later.
1495                 */
1496                node_child = of_get_next_child(node_root, NULL);
1497                while (node_child) {
1498                        vio_register_device_node(node_child);
1499                        node_child = of_get_next_child(node_root, node_child);
1500                }
1501                of_node_put(node_root);
1502        }
1503}
1504
1505/**
1506 * vio_bus_init: - Initialize the virtual IO bus
1507 */
1508static int __init vio_bus_init(void)
1509{
1510        int err;
1511
1512        if (firmware_has_feature(FW_FEATURE_CMO))
1513                vio_cmo_sysfs_init();
1514
1515        err = bus_register(&vio_bus_type);
1516        if (err) {
1517                printk(KERN_ERR "failed to register VIO bus\n");
1518                return err;
1519        }
1520
1521        /*
1522         * The fake parent of all vio devices, just to give us
1523         * a nice directory
1524         */
1525        err = device_register(&vio_bus_device.dev);
1526        if (err) {
1527                printk(KERN_WARNING "%s: device_register returned %i\n",
1528                                __func__, err);
1529                return err;
1530        }
1531
1532        if (firmware_has_feature(FW_FEATURE_CMO))
1533                vio_cmo_bus_init();
1534
1535        return 0;
1536}
1537machine_postcore_initcall(pseries, vio_bus_init);
1538
1539static int __init vio_device_init(void)
1540{
1541        vio_bus_scan_register_devices("vdevice");
1542        vio_bus_scan_register_devices("ibm,platform-facilities");
1543
1544        return 0;
1545}
1546machine_device_initcall(pseries, vio_device_init);
1547
1548static ssize_t name_show(struct device *dev,
1549                struct device_attribute *attr, char *buf)
1550{
1551        return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
1552}
1553static DEVICE_ATTR_RO(name);
1554
1555static ssize_t devspec_show(struct device *dev,
1556                struct device_attribute *attr, char *buf)
1557{
1558        struct device_node *of_node = dev->of_node;
1559
1560        return sprintf(buf, "%pOF\n", of_node);
1561}
1562static DEVICE_ATTR_RO(devspec);
1563
1564static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
1565                             char *buf)
1566{
1567        const struct vio_dev *vio_dev = to_vio_dev(dev);
1568        struct device_node *dn;
1569        const char *cp;
1570
1571        dn = dev->of_node;
1572        if (!dn) {
1573                strcpy(buf, "\n");
1574                return strlen(buf);
1575        }
1576        cp = of_get_property(dn, "compatible", NULL);
1577        if (!cp) {
1578                strcpy(buf, "\n");
1579                return strlen(buf);
1580        }
1581
1582        return sprintf(buf, "vio:T%sS%s\n", vio_dev->type, cp);
1583}
1584static DEVICE_ATTR_RO(modalias);
1585
1586static struct attribute *vio_dev_attrs[] = {
1587        &dev_attr_name.attr,
1588        &dev_attr_devspec.attr,
1589        &dev_attr_modalias.attr,
1590        NULL,
1591};
1592ATTRIBUTE_GROUPS(vio_dev);
1593
1594void vio_unregister_device(struct vio_dev *viodev)
1595{
1596        device_unregister(&viodev->dev);
1597        if (viodev->family == VDEVICE)
1598                irq_dispose_mapping(viodev->irq);
1599}
1600EXPORT_SYMBOL(vio_unregister_device);
1601
1602static int vio_bus_match(struct device *dev, struct device_driver *drv)
1603{
1604        const struct vio_dev *vio_dev = to_vio_dev(dev);
1605        struct vio_driver *vio_drv = to_vio_driver(drv);
1606        const struct vio_device_id *ids = vio_drv->id_table;
1607
1608        return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
1609}
1610
1611static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
1612{
1613        const struct vio_dev *vio_dev = to_vio_dev(dev);
1614        struct device_node *dn;
1615        const char *cp;
1616
1617        dn = dev->of_node;
1618        if (!dn)
1619                return -ENODEV;
1620        cp = of_get_property(dn, "compatible", NULL);
1621        if (!cp)
1622                return -ENODEV;
1623
1624        add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
1625        return 0;
1626}
1627
1628struct bus_type vio_bus_type = {
1629        .name = "vio",
1630        .dev_groups = vio_dev_groups,
1631        .uevent = vio_hotplug,
1632        .match = vio_bus_match,
1633        .probe = vio_bus_probe,
1634        .remove = vio_bus_remove,
1635        .shutdown = vio_bus_shutdown,
1636};
1637
1638/**
1639 * vio_get_attribute: - get attribute for virtual device
1640 * @vdev:       The vio device to get property.
1641 * @which:      The property/attribute to be extracted.
1642 * @length:     Pointer to length of returned data size (unused if NULL).
1643 *
1644 * Calls prom.c's of_get_property() to return the value of the
1645 * attribute specified by @which
1646*/
1647const void *vio_get_attribute(struct vio_dev *vdev, char *which, int *length)
1648{
1649        return of_get_property(vdev->dev.of_node, which, length);
1650}
1651EXPORT_SYMBOL(vio_get_attribute);
1652
1653/* vio_find_name() - internal because only vio.c knows how we formatted the
1654 * kobject name
1655 */
1656static struct vio_dev *vio_find_name(const char *name)
1657{
1658        struct device *found;
1659
1660        found = bus_find_device_by_name(&vio_bus_type, NULL, name);
1661        if (!found)
1662                return NULL;
1663
1664        return to_vio_dev(found);
1665}
1666
1667/**
1668 * vio_find_node - find an already-registered vio_dev
1669 * @vnode: device_node of the virtual device we're looking for
1670 *
1671 * Takes a reference to the embedded struct device which needs to be dropped
1672 * after use.
1673 */
1674struct vio_dev *vio_find_node(struct device_node *vnode)
1675{
1676        char kobj_name[20];
1677        struct device_node *vnode_parent;
1678
1679        vnode_parent = of_get_parent(vnode);
1680        if (!vnode_parent)
1681                return NULL;
1682
1683        /* construct the kobject name from the device node */
1684        if (of_node_is_type(vnode_parent, "vdevice")) {
1685                const __be32 *prop;
1686                
1687                prop = of_get_property(vnode, "reg", NULL);
1688                if (!prop)
1689                        goto out;
1690                snprintf(kobj_name, sizeof(kobj_name), "%x",
1691                         (uint32_t)of_read_number(prop, 1));
1692        } else if (of_node_is_type(vnode_parent, "ibm,platform-facilities"))
1693                snprintf(kobj_name, sizeof(kobj_name), "%pOFn", vnode);
1694        else
1695                goto out;
1696
1697        of_node_put(vnode_parent);
1698        return vio_find_name(kobj_name);
1699out:
1700        of_node_put(vnode_parent);
1701        return NULL;
1702}
1703EXPORT_SYMBOL(vio_find_node);
1704
1705int vio_enable_interrupts(struct vio_dev *dev)
1706{
1707        int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
1708        if (rc != H_SUCCESS)
1709                printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
1710        return rc;
1711}
1712EXPORT_SYMBOL(vio_enable_interrupts);
1713
1714int vio_disable_interrupts(struct vio_dev *dev)
1715{
1716        int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
1717        if (rc != H_SUCCESS)
1718                printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
1719        return rc;
1720}
1721EXPORT_SYMBOL(vio_disable_interrupts);
1722
1723static int __init vio_init(void)
1724{
1725        dma_debug_add_bus(&vio_bus_type);
1726        return 0;
1727}
1728machine_fs_initcall(pseries, vio_init);
1729