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TOMOYO Linux Cross Reference
Linux/arch/powerpc/kernel/vio.c

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  1 /*
  2  * IBM PowerPC Virtual I/O Infrastructure Support.
  3  *
  4  *    Copyright (c) 2003,2008 IBM Corp.
  5  *     Dave Engebretsen engebret@us.ibm.com
  6  *     Santiago Leon santil@us.ibm.com
  7  *     Hollis Blanchard <hollisb@us.ibm.com>
  8  *     Stephen Rothwell
  9  *     Robert Jennings <rcjenn@us.ibm.com>
 10  *
 11  *      This program is free software; you can redistribute it and/or
 12  *      modify it under the terms of the GNU General Public License
 13  *      as published by the Free Software Foundation; either version
 14  *      2 of the License, or (at your option) any later version.
 15  */
 16 
 17 #include <linux/types.h>
 18 #include <linux/device.h>
 19 #include <linux/init.h>
 20 #include <linux/console.h>
 21 #include <linux/module.h>
 22 #include <linux/mm.h>
 23 #include <linux/dma-mapping.h>
 24 #include <linux/kobject.h>
 25 
 26 #include <asm/iommu.h>
 27 #include <asm/dma.h>
 28 #include <asm/vio.h>
 29 #include <asm/prom.h>
 30 #include <asm/firmware.h>
 31 #include <asm/tce.h>
 32 #include <asm/abs_addr.h>
 33 #include <asm/page.h>
 34 #include <asm/hvcall.h>
 35 #include <asm/iseries/vio.h>
 36 #include <asm/iseries/hv_types.h>
 37 #include <asm/iseries/hv_lp_config.h>
 38 #include <asm/iseries/hv_call_xm.h>
 39 #include <asm/iseries/iommu.h>
 40 
 41 static struct bus_type vio_bus_type;
 42 
 43 static struct vio_dev vio_bus_device  = { /* fake "parent" device */
 44         .name = "vio",
 45         .type = "",
 46         .dev.init_name = "vio",
 47         .dev.bus = &vio_bus_type,
 48 };
 49 
 50 #ifdef CONFIG_PPC_SMLPAR
 51 /**
 52  * vio_cmo_pool - A pool of IO memory for CMO use
 53  *
 54  * @size: The size of the pool in bytes
 55  * @free: The amount of free memory in the pool
 56  */
 57 struct vio_cmo_pool {
 58         size_t size;
 59         size_t free;
 60 };
 61 
 62 /* How many ms to delay queued balance work */
 63 #define VIO_CMO_BALANCE_DELAY 100
 64 
 65 /* Portion out IO memory to CMO devices by this chunk size */
 66 #define VIO_CMO_BALANCE_CHUNK 131072
 67 
 68 /**
 69  * vio_cmo_dev_entry - A device that is CMO-enabled and requires entitlement
 70  *
 71  * @vio_dev: struct vio_dev pointer
 72  * @list: pointer to other devices on bus that are being tracked
 73  */
 74 struct vio_cmo_dev_entry {
 75         struct vio_dev *viodev;
 76         struct list_head list;
 77 };
 78 
 79 /**
 80  * vio_cmo - VIO bus accounting structure for CMO entitlement
 81  *
 82  * @lock: spinlock for entire structure
 83  * @balance_q: work queue for balancing system entitlement
 84  * @device_list: list of CMO-enabled devices requiring entitlement
 85  * @entitled: total system entitlement in bytes
 86  * @reserve: pool of memory from which devices reserve entitlement, incl. spare
 87  * @excess: pool of excess entitlement not needed for device reserves or spare
 88  * @spare: IO memory for device hotplug functionality
 89  * @min: minimum necessary for system operation
 90  * @desired: desired memory for system operation
 91  * @curr: bytes currently allocated
 92  * @high: high water mark for IO data usage
 93  */
 94 struct vio_cmo {
 95         spinlock_t lock;
 96         struct delayed_work balance_q;
 97         struct list_head device_list;
 98         size_t entitled;
 99         struct vio_cmo_pool reserve;
100         struct vio_cmo_pool excess;
101         size_t spare;
102         size_t min;
103         size_t desired;
104         size_t curr;
105         size_t high;
106 } vio_cmo;
107 
108 /**
109  * vio_cmo_OF_devices - Count the number of OF devices that have DMA windows
110  */
111 static int vio_cmo_num_OF_devs(void)
112 {
113         struct device_node *node_vroot;
114         int count = 0;
115 
116         /*
117          * Count the number of vdevice entries with an
118          * ibm,my-dma-window OF property
119          */
120         node_vroot = of_find_node_by_name(NULL, "vdevice");
121         if (node_vroot) {
122                 struct device_node *of_node;
123                 struct property *prop;
124 
125                 for_each_child_of_node(node_vroot, of_node) {
126                         prop = of_find_property(of_node, "ibm,my-dma-window",
127                                                NULL);
128                         if (prop)
129                                 count++;
130                 }
131         }
132         of_node_put(node_vroot);
133         return count;
134 }
135 
136 /**
137  * vio_cmo_alloc - allocate IO memory for CMO-enable devices
138  *
139  * @viodev: VIO device requesting IO memory
140  * @size: size of allocation requested
141  *
142  * Allocations come from memory reserved for the devices and any excess
143  * IO memory available to all devices.  The spare pool used to service
144  * hotplug must be equal to %VIO_CMO_MIN_ENT for the excess pool to be
145  * made available.
146  *
147  * Return codes:
148  *  0 for successful allocation and -ENOMEM for a failure
149  */
150 static inline int vio_cmo_alloc(struct vio_dev *viodev, size_t size)
151 {
152         unsigned long flags;
153         size_t reserve_free = 0;
154         size_t excess_free = 0;
155         int ret = -ENOMEM;
156 
157         spin_lock_irqsave(&vio_cmo.lock, flags);
158 
159         /* Determine the amount of free entitlement available in reserve */
160         if (viodev->cmo.entitled > viodev->cmo.allocated)
161                 reserve_free = viodev->cmo.entitled - viodev->cmo.allocated;
162 
163         /* If spare is not fulfilled, the excess pool can not be used. */
164         if (vio_cmo.spare >= VIO_CMO_MIN_ENT)
165                 excess_free = vio_cmo.excess.free;
166 
167         /* The request can be satisfied */
168         if ((reserve_free + excess_free) >= size) {
169                 vio_cmo.curr += size;
170                 if (vio_cmo.curr > vio_cmo.high)
171                         vio_cmo.high = vio_cmo.curr;
172                 viodev->cmo.allocated += size;
173                 size -= min(reserve_free, size);
174                 vio_cmo.excess.free -= size;
175                 ret = 0;
176         }
177 
178         spin_unlock_irqrestore(&vio_cmo.lock, flags);
179         return ret;
180 }
181 
182 /**
183  * vio_cmo_dealloc - deallocate IO memory from CMO-enable devices
184  * @viodev: VIO device freeing IO memory
185  * @size: size of deallocation
186  *
187  * IO memory is freed by the device back to the correct memory pools.
188  * The spare pool is replenished first from either memory pool, then
189  * the reserve pool is used to reduce device entitlement, the excess
190  * pool is used to increase the reserve pool toward the desired entitlement
191  * target, and then the remaining memory is returned to the pools.
192  *
193  */
194 static inline void vio_cmo_dealloc(struct vio_dev *viodev, size_t size)
195 {
196         unsigned long flags;
197         size_t spare_needed = 0;
198         size_t excess_freed = 0;
199         size_t reserve_freed = size;
200         size_t tmp;
201         int balance = 0;
202 
203         spin_lock_irqsave(&vio_cmo.lock, flags);
204         vio_cmo.curr -= size;
205 
206         /* Amount of memory freed from the excess pool */
207         if (viodev->cmo.allocated > viodev->cmo.entitled) {
208                 excess_freed = min(reserve_freed, (viodev->cmo.allocated -
209                                                    viodev->cmo.entitled));
210                 reserve_freed -= excess_freed;
211         }
212 
213         /* Remove allocation from device */
214         viodev->cmo.allocated -= (reserve_freed + excess_freed);
215 
216         /* Spare is a subset of the reserve pool, replenish it first. */
217         spare_needed = VIO_CMO_MIN_ENT - vio_cmo.spare;
218 
219         /*
220          * Replenish the spare in the reserve pool from the excess pool.
221          * This moves entitlement into the reserve pool.
222          */
223         if (spare_needed && excess_freed) {
224                 tmp = min(excess_freed, spare_needed);
225                 vio_cmo.excess.size -= tmp;
226                 vio_cmo.reserve.size += tmp;
227                 vio_cmo.spare += tmp;
228                 excess_freed -= tmp;
229                 spare_needed -= tmp;
230                 balance = 1;
231         }
232 
233         /*
234          * Replenish the spare in the reserve pool from the reserve pool.
235          * This removes entitlement from the device down to VIO_CMO_MIN_ENT,
236          * if needed, and gives it to the spare pool. The amount of used
237          * memory in this pool does not change.
238          */
239         if (spare_needed && reserve_freed) {
240                 tmp = min(spare_needed, min(reserve_freed,
241                                             (viodev->cmo.entitled -
242                                              VIO_CMO_MIN_ENT)));
243 
244                 vio_cmo.spare += tmp;
245                 viodev->cmo.entitled -= tmp;
246                 reserve_freed -= tmp;
247                 spare_needed -= tmp;
248                 balance = 1;
249         }
250 
251         /*
252          * Increase the reserve pool until the desired allocation is met.
253          * Move an allocation freed from the excess pool into the reserve
254          * pool and schedule a balance operation.
255          */
256         if (excess_freed && (vio_cmo.desired > vio_cmo.reserve.size)) {
257                 tmp = min(excess_freed, (vio_cmo.desired - vio_cmo.reserve.size));
258 
259                 vio_cmo.excess.size -= tmp;
260                 vio_cmo.reserve.size += tmp;
261                 excess_freed -= tmp;
262                 balance = 1;
263         }
264 
265         /* Return memory from the excess pool to that pool */
266         if (excess_freed)
267                 vio_cmo.excess.free += excess_freed;
268 
269         if (balance)
270                 schedule_delayed_work(&vio_cmo.balance_q, VIO_CMO_BALANCE_DELAY);
271         spin_unlock_irqrestore(&vio_cmo.lock, flags);
272 }
273 
274 /**
275  * vio_cmo_entitlement_update - Manage system entitlement changes
276  *
277  * @new_entitlement: new system entitlement to attempt to accommodate
278  *
279  * Increases in entitlement will be used to fulfill the spare entitlement
280  * and the rest is given to the excess pool.  Decreases, if they are
281  * possible, come from the excess pool and from unused device entitlement
282  *
283  * Returns: 0 on success, -ENOMEM when change can not be made
284  */
285 int vio_cmo_entitlement_update(size_t new_entitlement)
286 {
287         struct vio_dev *viodev;
288         struct vio_cmo_dev_entry *dev_ent;
289         unsigned long flags;
290         size_t avail, delta, tmp;
291 
292         spin_lock_irqsave(&vio_cmo.lock, flags);
293 
294         /* Entitlement increases */
295         if (new_entitlement > vio_cmo.entitled) {
296                 delta = new_entitlement - vio_cmo.entitled;
297 
298                 /* Fulfill spare allocation */
299                 if (vio_cmo.spare < VIO_CMO_MIN_ENT) {
300                         tmp = min(delta, (VIO_CMO_MIN_ENT - vio_cmo.spare));
301                         vio_cmo.spare += tmp;
302                         vio_cmo.reserve.size += tmp;
303                         delta -= tmp;
304                 }
305 
306                 /* Remaining new allocation goes to the excess pool */
307                 vio_cmo.entitled += delta;
308                 vio_cmo.excess.size += delta;
309                 vio_cmo.excess.free += delta;
310 
311                 goto out;
312         }
313 
314         /* Entitlement decreases */
315         delta = vio_cmo.entitled - new_entitlement;
316         avail = vio_cmo.excess.free;
317 
318         /*
319          * Need to check how much unused entitlement each device can
320          * sacrifice to fulfill entitlement change.
321          */
322         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
323                 if (avail >= delta)
324                         break;
325 
326                 viodev = dev_ent->viodev;
327                 if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
328                     (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
329                                 avail += viodev->cmo.entitled -
330                                          max_t(size_t, viodev->cmo.allocated,
331                                                VIO_CMO_MIN_ENT);
332         }
333 
334         if (delta <= avail) {
335                 vio_cmo.entitled -= delta;
336 
337                 /* Take entitlement from the excess pool first */
338                 tmp = min(vio_cmo.excess.free, delta);
339                 vio_cmo.excess.size -= tmp;
340                 vio_cmo.excess.free -= tmp;
341                 delta -= tmp;
342 
343                 /*
344                  * Remove all but VIO_CMO_MIN_ENT bytes from devices
345                  * until entitlement change is served
346                  */
347                 list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
348                         if (!delta)
349                                 break;
350 
351                         viodev = dev_ent->viodev;
352                         tmp = 0;
353                         if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
354                             (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
355                                 tmp = viodev->cmo.entitled -
356                                       max_t(size_t, viodev->cmo.allocated,
357                                             VIO_CMO_MIN_ENT);
358                         viodev->cmo.entitled -= min(tmp, delta);
359                         delta -= min(tmp, delta);
360                 }
361         } else {
362                 spin_unlock_irqrestore(&vio_cmo.lock, flags);
363                 return -ENOMEM;
364         }
365 
366 out:
367         schedule_delayed_work(&vio_cmo.balance_q, 0);
368         spin_unlock_irqrestore(&vio_cmo.lock, flags);
369         return 0;
370 }
371 
372 /**
373  * vio_cmo_balance - Balance entitlement among devices
374  *
375  * @work: work queue structure for this operation
376  *
377  * Any system entitlement above the minimum needed for devices, or
378  * already allocated to devices, can be distributed to the devices.
379  * The list of devices is iterated through to recalculate the desired
380  * entitlement level and to determine how much entitlement above the
381  * minimum entitlement is allocated to devices.
382  *
383  * Small chunks of the available entitlement are given to devices until
384  * their requirements are fulfilled or there is no entitlement left to give.
385  * Upon completion sizes of the reserve and excess pools are calculated.
386  *
387  * The system minimum entitlement level is also recalculated here.
388  * Entitlement will be reserved for devices even after vio_bus_remove to
389  * accommodate reloading the driver.  The OF tree is walked to count the
390  * number of devices present and this will remove entitlement for devices
391  * that have actually left the system after having vio_bus_remove called.
392  */
393 static void vio_cmo_balance(struct work_struct *work)
394 {
395         struct vio_cmo *cmo;
396         struct vio_dev *viodev;
397         struct vio_cmo_dev_entry *dev_ent;
398         unsigned long flags;
399         size_t avail = 0, level, chunk, need;
400         int devcount = 0, fulfilled;
401 
402         cmo = container_of(work, struct vio_cmo, balance_q.work);
403 
404         spin_lock_irqsave(&vio_cmo.lock, flags);
405 
406         /* Calculate minimum entitlement and fulfill spare */
407         cmo->min = vio_cmo_num_OF_devs() * VIO_CMO_MIN_ENT;
408         BUG_ON(cmo->min > cmo->entitled);
409         cmo->spare = min_t(size_t, VIO_CMO_MIN_ENT, (cmo->entitled - cmo->min));
410         cmo->min += cmo->spare;
411         cmo->desired = cmo->min;
412 
413         /*
414          * Determine how much entitlement is available and reset device
415          * entitlements
416          */
417         avail = cmo->entitled - cmo->spare;
418         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
419                 viodev = dev_ent->viodev;
420                 devcount++;
421                 viodev->cmo.entitled = VIO_CMO_MIN_ENT;
422                 cmo->desired += (viodev->cmo.desired - VIO_CMO_MIN_ENT);
423                 avail -= max_t(size_t, viodev->cmo.allocated, VIO_CMO_MIN_ENT);
424         }
425 
426         /*
427          * Having provided each device with the minimum entitlement, loop
428          * over the devices portioning out the remaining entitlement
429          * until there is nothing left.
430          */
431         level = VIO_CMO_MIN_ENT;
432         while (avail) {
433                 fulfilled = 0;
434                 list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
435                         viodev = dev_ent->viodev;
436 
437                         if (viodev->cmo.desired <= level) {
438                                 fulfilled++;
439                                 continue;
440                         }
441 
442                         /*
443                          * Give the device up to VIO_CMO_BALANCE_CHUNK
444                          * bytes of entitlement, but do not exceed the
445                          * desired level of entitlement for the device.
446                          */
447                         chunk = min_t(size_t, avail, VIO_CMO_BALANCE_CHUNK);
448                         chunk = min(chunk, (viodev->cmo.desired -
449                                             viodev->cmo.entitled));
450                         viodev->cmo.entitled += chunk;
451 
452                         /*
453                          * If the memory for this entitlement increase was
454                          * already allocated to the device it does not come
455                          * from the available pool being portioned out.
456                          */
457                         need = max(viodev->cmo.allocated, viodev->cmo.entitled)-
458                                max(viodev->cmo.allocated, level);
459                         avail -= need;
460 
461                 }
462                 if (fulfilled == devcount)
463                         break;
464                 level += VIO_CMO_BALANCE_CHUNK;
465         }
466 
467         /* Calculate new reserve and excess pool sizes */
468         cmo->reserve.size = cmo->min;
469         cmo->excess.free = 0;
470         cmo->excess.size = 0;
471         need = 0;
472         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
473                 viodev = dev_ent->viodev;
474                 /* Calculated reserve size above the minimum entitlement */
475                 if (viodev->cmo.entitled)
476                         cmo->reserve.size += (viodev->cmo.entitled -
477                                               VIO_CMO_MIN_ENT);
478                 /* Calculated used excess entitlement */
479                 if (viodev->cmo.allocated > viodev->cmo.entitled)
480                         need += viodev->cmo.allocated - viodev->cmo.entitled;
481         }
482         cmo->excess.size = cmo->entitled - cmo->reserve.size;
483         cmo->excess.free = cmo->excess.size - need;
484 
485         cancel_delayed_work(to_delayed_work(work));
486         spin_unlock_irqrestore(&vio_cmo.lock, flags);
487 }
488 
489 static void *vio_dma_iommu_alloc_coherent(struct device *dev, size_t size,
490                                           dma_addr_t *dma_handle, gfp_t flag)
491 {
492         struct vio_dev *viodev = to_vio_dev(dev);
493         void *ret;
494 
495         if (vio_cmo_alloc(viodev, roundup(size, PAGE_SIZE))) {
496                 atomic_inc(&viodev->cmo.allocs_failed);
497                 return NULL;
498         }
499 
500         ret = dma_iommu_ops.alloc_coherent(dev, size, dma_handle, flag);
501         if (unlikely(ret == NULL)) {
502                 vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
503                 atomic_inc(&viodev->cmo.allocs_failed);
504         }
505 
506         return ret;
507 }
508 
509 static void vio_dma_iommu_free_coherent(struct device *dev, size_t size,
510                                         void *vaddr, dma_addr_t dma_handle)
511 {
512         struct vio_dev *viodev = to_vio_dev(dev);
513 
514         dma_iommu_ops.free_coherent(dev, size, vaddr, dma_handle);
515 
516         vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
517 }
518 
519 static dma_addr_t vio_dma_iommu_map_page(struct device *dev, struct page *page,
520                                          unsigned long offset, size_t size,
521                                          enum dma_data_direction direction,
522                                          struct dma_attrs *attrs)
523 {
524         struct vio_dev *viodev = to_vio_dev(dev);
525         dma_addr_t ret = DMA_ERROR_CODE;
526 
527         if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE))) {
528                 atomic_inc(&viodev->cmo.allocs_failed);
529                 return ret;
530         }
531 
532         ret = dma_iommu_ops.map_page(dev, page, offset, size, direction, attrs);
533         if (unlikely(dma_mapping_error(dev, ret))) {
534                 vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE));
535                 atomic_inc(&viodev->cmo.allocs_failed);
536         }
537 
538         return ret;
539 }
540 
541 static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
542                                      size_t size,
543                                      enum dma_data_direction direction,
544                                      struct dma_attrs *attrs)
545 {
546         struct vio_dev *viodev = to_vio_dev(dev);
547 
548         dma_iommu_ops.unmap_page(dev, dma_handle, size, direction, attrs);
549 
550         vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE));
551 }
552 
553 static int vio_dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist,
554                                 int nelems, enum dma_data_direction direction,
555                                 struct dma_attrs *attrs)
556 {
557         struct vio_dev *viodev = to_vio_dev(dev);
558         struct scatterlist *sgl;
559         int ret, count = 0;
560         size_t alloc_size = 0;
561 
562         for (sgl = sglist; count < nelems; count++, sgl++)
563                 alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE);
564 
565         if (vio_cmo_alloc(viodev, alloc_size)) {
566                 atomic_inc(&viodev->cmo.allocs_failed);
567                 return 0;
568         }
569 
570         ret = dma_iommu_ops.map_sg(dev, sglist, nelems, direction, attrs);
571 
572         if (unlikely(!ret)) {
573                 vio_cmo_dealloc(viodev, alloc_size);
574                 atomic_inc(&viodev->cmo.allocs_failed);
575                 return ret;
576         }
577 
578         for (sgl = sglist, count = 0; count < ret; count++, sgl++)
579                 alloc_size -= roundup(sgl->dma_length, IOMMU_PAGE_SIZE);
580         if (alloc_size)
581                 vio_cmo_dealloc(viodev, alloc_size);
582 
583         return ret;
584 }
585 
586 static void vio_dma_iommu_unmap_sg(struct device *dev,
587                 struct scatterlist *sglist, int nelems,
588                 enum dma_data_direction direction,
589                 struct dma_attrs *attrs)
590 {
591         struct vio_dev *viodev = to_vio_dev(dev);
592         struct scatterlist *sgl;
593         size_t alloc_size = 0;
594         int count = 0;
595 
596         for (sgl = sglist; count < nelems; count++, sgl++)
597                 alloc_size += roundup(sgl->dma_length, IOMMU_PAGE_SIZE);
598 
599         dma_iommu_ops.unmap_sg(dev, sglist, nelems, direction, attrs);
600 
601         vio_cmo_dealloc(viodev, alloc_size);
602 }
603 
604 struct dma_map_ops vio_dma_mapping_ops = {
605         .alloc_coherent = vio_dma_iommu_alloc_coherent,
606         .free_coherent  = vio_dma_iommu_free_coherent,
607         .map_sg         = vio_dma_iommu_map_sg,
608         .unmap_sg       = vio_dma_iommu_unmap_sg,
609         .map_page       = vio_dma_iommu_map_page,
610         .unmap_page     = vio_dma_iommu_unmap_page,
611 
612 };
613 
614 /**
615  * vio_cmo_set_dev_desired - Set desired entitlement for a device
616  *
617  * @viodev: struct vio_dev for device to alter
618  * @new_desired: new desired entitlement level in bytes
619  *
620  * For use by devices to request a change to their entitlement at runtime or
621  * through sysfs.  The desired entitlement level is changed and a balancing
622  * of system resources is scheduled to run in the future.
623  */
624 void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired)
625 {
626         unsigned long flags;
627         struct vio_cmo_dev_entry *dev_ent;
628         int found = 0;
629 
630         if (!firmware_has_feature(FW_FEATURE_CMO))
631                 return;
632 
633         spin_lock_irqsave(&vio_cmo.lock, flags);
634         if (desired < VIO_CMO_MIN_ENT)
635                 desired = VIO_CMO_MIN_ENT;
636 
637         /*
638          * Changes will not be made for devices not in the device list.
639          * If it is not in the device list, then no driver is loaded
640          * for the device and it can not receive entitlement.
641          */
642         list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
643                 if (viodev == dev_ent->viodev) {
644                         found = 1;
645                         break;
646                 }
647         if (!found)
648                 return;
649 
650         /* Increase/decrease in desired device entitlement */
651         if (desired >= viodev->cmo.desired) {
652                 /* Just bump the bus and device values prior to a balance*/
653                 vio_cmo.desired += desired - viodev->cmo.desired;
654                 viodev->cmo.desired = desired;
655         } else {
656                 /* Decrease bus and device values for desired entitlement */
657                 vio_cmo.desired -= viodev->cmo.desired - desired;
658                 viodev->cmo.desired = desired;
659                 /*
660                  * If less entitlement is desired than current entitlement, move
661                  * any reserve memory in the change region to the excess pool.
662                  */
663                 if (viodev->cmo.entitled > desired) {
664                         vio_cmo.reserve.size -= viodev->cmo.entitled - desired;
665                         vio_cmo.excess.size += viodev->cmo.entitled - desired;
666                         /*
667                          * If entitlement moving from the reserve pool to the
668                          * excess pool is currently unused, add to the excess
669                          * free counter.
670                          */
671                         if (viodev->cmo.allocated < viodev->cmo.entitled)
672                                 vio_cmo.excess.free += viodev->cmo.entitled -
673                                                        max(viodev->cmo.allocated, desired);
674                         viodev->cmo.entitled = desired;
675                 }
676         }
677         schedule_delayed_work(&vio_cmo.balance_q, 0);
678         spin_unlock_irqrestore(&vio_cmo.lock, flags);
679 }
680 
681 /**
682  * vio_cmo_bus_probe - Handle CMO specific bus probe activities
683  *
684  * @viodev - Pointer to struct vio_dev for device
685  *
686  * Determine the devices IO memory entitlement needs, attempting
687  * to satisfy the system minimum entitlement at first and scheduling
688  * a balance operation to take care of the rest at a later time.
689  *
690  * Returns: 0 on success, -EINVAL when device doesn't support CMO, and
691  *          -ENOMEM when entitlement is not available for device or
692  *          device entry.
693  *
694  */
695 static int vio_cmo_bus_probe(struct vio_dev *viodev)
696 {
697         struct vio_cmo_dev_entry *dev_ent;
698         struct device *dev = &viodev->dev;
699         struct vio_driver *viodrv = to_vio_driver(dev->driver);
700         unsigned long flags;
701         size_t size;
702 
703         /*
704          * Check to see that device has a DMA window and configure
705          * entitlement for the device.
706          */
707         if (of_get_property(viodev->dev.archdata.of_node,
708                             "ibm,my-dma-window", NULL)) {
709                 /* Check that the driver is CMO enabled and get desired DMA */
710                 if (!viodrv->get_desired_dma) {
711                         dev_err(dev, "%s: device driver does not support CMO\n",
712                                 __func__);
713                         return -EINVAL;
714                 }
715 
716                 viodev->cmo.desired = IOMMU_PAGE_ALIGN(viodrv->get_desired_dma(viodev));
717                 if (viodev->cmo.desired < VIO_CMO_MIN_ENT)
718                         viodev->cmo.desired = VIO_CMO_MIN_ENT;
719                 size = VIO_CMO_MIN_ENT;
720 
721                 dev_ent = kmalloc(sizeof(struct vio_cmo_dev_entry),
722                                   GFP_KERNEL);
723                 if (!dev_ent)
724                         return -ENOMEM;
725 
726                 dev_ent->viodev = viodev;
727                 spin_lock_irqsave(&vio_cmo.lock, flags);
728                 list_add(&dev_ent->list, &vio_cmo.device_list);
729         } else {
730                 viodev->cmo.desired = 0;
731                 size = 0;
732                 spin_lock_irqsave(&vio_cmo.lock, flags);
733         }
734 
735         /*
736          * If the needs for vio_cmo.min have not changed since they
737          * were last set, the number of devices in the OF tree has
738          * been constant and the IO memory for this is already in
739          * the reserve pool.
740          */
741         if (vio_cmo.min == ((vio_cmo_num_OF_devs() + 1) *
742                             VIO_CMO_MIN_ENT)) {
743                 /* Updated desired entitlement if device requires it */
744                 if (size)
745                         vio_cmo.desired += (viodev->cmo.desired -
746                                         VIO_CMO_MIN_ENT);
747         } else {
748                 size_t tmp;
749 
750                 tmp = vio_cmo.spare + vio_cmo.excess.free;
751                 if (tmp < size) {
752                         dev_err(dev, "%s: insufficient free "
753                                 "entitlement to add device. "
754                                 "Need %lu, have %lu\n", __func__,
755                                 size, (vio_cmo.spare + tmp));
756                         spin_unlock_irqrestore(&vio_cmo.lock, flags);
757                         return -ENOMEM;
758                 }
759 
760                 /* Use excess pool first to fulfill request */
761                 tmp = min(size, vio_cmo.excess.free);
762                 vio_cmo.excess.free -= tmp;
763                 vio_cmo.excess.size -= tmp;
764                 vio_cmo.reserve.size += tmp;
765 
766                 /* Use spare if excess pool was insufficient */
767                 vio_cmo.spare -= size - tmp;
768 
769                 /* Update bus accounting */
770                 vio_cmo.min += size;
771                 vio_cmo.desired += viodev->cmo.desired;
772         }
773         spin_unlock_irqrestore(&vio_cmo.lock, flags);
774         return 0;
775 }
776 
777 /**
778  * vio_cmo_bus_remove - Handle CMO specific bus removal activities
779  *
780  * @viodev - Pointer to struct vio_dev for device
781  *
782  * Remove the device from the cmo device list.  The minimum entitlement
783  * will be reserved for the device as long as it is in the system.  The
784  * rest of the entitlement the device had been allocated will be returned
785  * to the system.
786  */
787 static void vio_cmo_bus_remove(struct vio_dev *viodev)
788 {
789         struct vio_cmo_dev_entry *dev_ent;
790         unsigned long flags;
791         size_t tmp;
792 
793         spin_lock_irqsave(&vio_cmo.lock, flags);
794         if (viodev->cmo.allocated) {
795                 dev_err(&viodev->dev, "%s: device had %lu bytes of IO "
796                         "allocated after remove operation.\n",
797                         __func__, viodev->cmo.allocated);
798                 BUG();
799         }
800 
801         /*
802          * Remove the device from the device list being maintained for
803          * CMO enabled devices.
804          */
805         list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
806                 if (viodev == dev_ent->viodev) {
807                         list_del(&dev_ent->list);
808                         kfree(dev_ent);
809                         break;
810                 }
811 
812         /*
813          * Devices may not require any entitlement and they do not need
814          * to be processed.  Otherwise, return the device's entitlement
815          * back to the pools.
816          */
817         if (viodev->cmo.entitled) {
818                 /*
819                  * This device has not yet left the OF tree, it's
820                  * minimum entitlement remains in vio_cmo.min and
821                  * vio_cmo.desired
822                  */
823                 vio_cmo.desired -= (viodev->cmo.desired - VIO_CMO_MIN_ENT);
824 
825                 /*
826                  * Save min allocation for device in reserve as long
827                  * as it exists in OF tree as determined by later
828                  * balance operation
829                  */
830                 viodev->cmo.entitled -= VIO_CMO_MIN_ENT;
831 
832                 /* Replenish spare from freed reserve pool */
833                 if (viodev->cmo.entitled && (vio_cmo.spare < VIO_CMO_MIN_ENT)) {
834                         tmp = min(viodev->cmo.entitled, (VIO_CMO_MIN_ENT -
835                                                          vio_cmo.spare));
836                         vio_cmo.spare += tmp;
837                         viodev->cmo.entitled -= tmp;
838                 }
839 
840                 /* Remaining reserve goes to excess pool */
841                 vio_cmo.excess.size += viodev->cmo.entitled;
842                 vio_cmo.excess.free += viodev->cmo.entitled;
843                 vio_cmo.reserve.size -= viodev->cmo.entitled;
844 
845                 /*
846                  * Until the device is removed it will keep a
847                  * minimum entitlement; this will guarantee that
848                  * a module unload/load will result in a success.
849                  */
850                 viodev->cmo.entitled = VIO_CMO_MIN_ENT;
851                 viodev->cmo.desired = VIO_CMO_MIN_ENT;
852                 atomic_set(&viodev->cmo.allocs_failed, 0);
853         }
854 
855         spin_unlock_irqrestore(&vio_cmo.lock, flags);
856 }
857 
858 static void vio_cmo_set_dma_ops(struct vio_dev *viodev)
859 {
860         vio_dma_mapping_ops.dma_supported = dma_iommu_ops.dma_supported;
861         viodev->dev.archdata.dma_ops = &vio_dma_mapping_ops;
862 }
863 
864 /**
865  * vio_cmo_bus_init - CMO entitlement initialization at bus init time
866  *
867  * Set up the reserve and excess entitlement pools based on available
868  * system entitlement and the number of devices in the OF tree that
869  * require entitlement in the reserve pool.
870  */
871 static void vio_cmo_bus_init(void)
872 {
873         struct hvcall_mpp_data mpp_data;
874         int err;
875 
876         memset(&vio_cmo, 0, sizeof(struct vio_cmo));
877         spin_lock_init(&vio_cmo.lock);
878         INIT_LIST_HEAD(&vio_cmo.device_list);
879         INIT_DELAYED_WORK(&vio_cmo.balance_q, vio_cmo_balance);
880 
881         /* Get current system entitlement */
882         err = h_get_mpp(&mpp_data);
883 
884         /*
885          * On failure, continue with entitlement set to 0, will panic()
886          * later when spare is reserved.
887          */
888         if (err != H_SUCCESS) {
889                 printk(KERN_ERR "%s: unable to determine system IO "\
890                        "entitlement. (%d)\n", __func__, err);
891                 vio_cmo.entitled = 0;
892         } else {
893                 vio_cmo.entitled = mpp_data.entitled_mem;
894         }
895 
896         /* Set reservation and check against entitlement */
897         vio_cmo.spare = VIO_CMO_MIN_ENT;
898         vio_cmo.reserve.size = vio_cmo.spare;
899         vio_cmo.reserve.size += (vio_cmo_num_OF_devs() *
900                                  VIO_CMO_MIN_ENT);
901         if (vio_cmo.reserve.size > vio_cmo.entitled) {
902                 printk(KERN_ERR "%s: insufficient system entitlement\n",
903                        __func__);
904                 panic("%s: Insufficient system entitlement", __func__);
905         }
906 
907         /* Set the remaining accounting variables */
908         vio_cmo.excess.size = vio_cmo.entitled - vio_cmo.reserve.size;
909         vio_cmo.excess.free = vio_cmo.excess.size;
910         vio_cmo.min = vio_cmo.reserve.size;
911         vio_cmo.desired = vio_cmo.reserve.size;
912 }
913 
914 /* sysfs device functions and data structures for CMO */
915 
916 #define viodev_cmo_rd_attr(name)                                        \
917 static ssize_t viodev_cmo_##name##_show(struct device *dev,             \
918                                         struct device_attribute *attr,  \
919                                          char *buf)                     \
920 {                                                                       \
921         return sprintf(buf, "%lu\n", to_vio_dev(dev)->cmo.name);        \
922 }
923 
924 static ssize_t viodev_cmo_allocs_failed_show(struct device *dev,
925                 struct device_attribute *attr, char *buf)
926 {
927         struct vio_dev *viodev = to_vio_dev(dev);
928         return sprintf(buf, "%d\n", atomic_read(&viodev->cmo.allocs_failed));
929 }
930 
931 static ssize_t viodev_cmo_allocs_failed_reset(struct device *dev,
932                 struct device_attribute *attr, const char *buf, size_t count)
933 {
934         struct vio_dev *viodev = to_vio_dev(dev);
935         atomic_set(&viodev->cmo.allocs_failed, 0);
936         return count;
937 }
938 
939 static ssize_t viodev_cmo_desired_set(struct device *dev,
940                 struct device_attribute *attr, const char *buf, size_t count)
941 {
942         struct vio_dev *viodev = to_vio_dev(dev);
943         size_t new_desired;
944         int ret;
945 
946         ret = strict_strtoul(buf, 10, &new_desired);
947         if (ret)
948                 return ret;
949 
950         vio_cmo_set_dev_desired(viodev, new_desired);
951         return count;
952 }
953 
954 viodev_cmo_rd_attr(desired);
955 viodev_cmo_rd_attr(entitled);
956 viodev_cmo_rd_attr(allocated);
957 
958 static ssize_t name_show(struct device *, struct device_attribute *, char *);
959 static ssize_t devspec_show(struct device *, struct device_attribute *, char *);
960 static struct device_attribute vio_cmo_dev_attrs[] = {
961         __ATTR_RO(name),
962         __ATTR_RO(devspec),
963         __ATTR(cmo_desired,       S_IWUSR|S_IRUSR|S_IWGRP|S_IRGRP|S_IROTH,
964                viodev_cmo_desired_show, viodev_cmo_desired_set),
965         __ATTR(cmo_entitled,      S_IRUGO, viodev_cmo_entitled_show,      NULL),
966         __ATTR(cmo_allocated,     S_IRUGO, viodev_cmo_allocated_show,     NULL),
967         __ATTR(cmo_allocs_failed, S_IWUSR|S_IRUSR|S_IWGRP|S_IRGRP|S_IROTH,
968                viodev_cmo_allocs_failed_show, viodev_cmo_allocs_failed_reset),
969         __ATTR_NULL
970 };
971 
972 /* sysfs bus functions and data structures for CMO */
973 
974 #define viobus_cmo_rd_attr(name)                                        \
975 static ssize_t                                                          \
976 viobus_cmo_##name##_show(struct bus_type *bt, char *buf)                \
977 {                                                                       \
978         return sprintf(buf, "%lu\n", vio_cmo.name);                     \
979 }
980 
981 #define viobus_cmo_pool_rd_attr(name, var)                              \
982 static ssize_t                                                          \
983 viobus_cmo_##name##_pool_show_##var(struct bus_type *bt, char *buf)     \
984 {                                                                       \
985         return sprintf(buf, "%lu\n", vio_cmo.name.var);                 \
986 }
987 
988 static ssize_t viobus_cmo_high_reset(struct bus_type *bt, const char *buf,
989                                      size_t count)
990 {
991         unsigned long flags;
992 
993         spin_lock_irqsave(&vio_cmo.lock, flags);
994         vio_cmo.high = vio_cmo.curr;
995         spin_unlock_irqrestore(&vio_cmo.lock, flags);
996 
997         return count;
998 }
999 
1000 viobus_cmo_rd_attr(entitled);
1001 viobus_cmo_pool_rd_attr(reserve, size);
1002 viobus_cmo_pool_rd_attr(excess, size);
1003 viobus_cmo_pool_rd_attr(excess, free);
1004 viobus_cmo_rd_attr(spare);
1005 viobus_cmo_rd_attr(min);
1006 viobus_cmo_rd_attr(desired);
1007 viobus_cmo_rd_attr(curr);
1008 viobus_cmo_rd_attr(high);
1009 
1010 static struct bus_attribute vio_cmo_bus_attrs[] = {
1011         __ATTR(cmo_entitled, S_IRUGO, viobus_cmo_entitled_show, NULL),
1012         __ATTR(cmo_reserve_size, S_IRUGO, viobus_cmo_reserve_pool_show_size, NULL),
1013         __ATTR(cmo_excess_size, S_IRUGO, viobus_cmo_excess_pool_show_size, NULL),
1014         __ATTR(cmo_excess_free, S_IRUGO, viobus_cmo_excess_pool_show_free, NULL),
1015         __ATTR(cmo_spare,   S_IRUGO, viobus_cmo_spare_show,   NULL),
1016         __ATTR(cmo_min,     S_IRUGO, viobus_cmo_min_show,     NULL),
1017         __ATTR(cmo_desired, S_IRUGO, viobus_cmo_desired_show, NULL),
1018         __ATTR(cmo_curr,    S_IRUGO, viobus_cmo_curr_show,    NULL),
1019         __ATTR(cmo_high,    S_IWUSR|S_IRUSR|S_IWGRP|S_IRGRP|S_IROTH,
1020                viobus_cmo_high_show, viobus_cmo_high_reset),
1021         __ATTR_NULL
1022 };
1023 
1024 static void vio_cmo_sysfs_init(void)
1025 {
1026         vio_bus_type.dev_attrs = vio_cmo_dev_attrs;
1027         vio_bus_type.bus_attrs = vio_cmo_bus_attrs;
1028 }
1029 #else /* CONFIG_PPC_SMLPAR */
1030 /* Dummy functions for iSeries platform */
1031 int vio_cmo_entitlement_update(size_t new_entitlement) { return 0; }
1032 void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired) {}
1033 static int vio_cmo_bus_probe(struct vio_dev *viodev) { return 0; }
1034 static void vio_cmo_bus_remove(struct vio_dev *viodev) {}
1035 static void vio_cmo_set_dma_ops(struct vio_dev *viodev) {}
1036 static void vio_cmo_bus_init(void) {}
1037 static void vio_cmo_sysfs_init(void) { }
1038 #endif /* CONFIG_PPC_SMLPAR */
1039 EXPORT_SYMBOL(vio_cmo_entitlement_update);
1040 EXPORT_SYMBOL(vio_cmo_set_dev_desired);
1041 
1042 static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
1043 {
1044         const unsigned char *dma_window;
1045         struct iommu_table *tbl;
1046         unsigned long offset, size;
1047 
1048         if (firmware_has_feature(FW_FEATURE_ISERIES))
1049                 return vio_build_iommu_table_iseries(dev);
1050 
1051         dma_window = of_get_property(dev->dev.archdata.of_node,
1052                                   "ibm,my-dma-window", NULL);
1053         if (!dma_window)
1054                 return NULL;
1055 
1056         tbl = kmalloc(sizeof(*tbl), GFP_KERNEL);
1057         if (tbl == NULL)
1058                 return NULL;
1059 
1060         of_parse_dma_window(dev->dev.archdata.of_node, dma_window,
1061                             &tbl->it_index, &offset, &size);
1062 
1063         /* TCE table size - measured in tce entries */
1064         tbl->it_size = size >> IOMMU_PAGE_SHIFT;
1065         /* offset for VIO should always be 0 */
1066         tbl->it_offset = offset >> IOMMU_PAGE_SHIFT;
1067         tbl->it_busno = 0;
1068         tbl->it_type = TCE_VB;
1069 
1070         return iommu_init_table(tbl, -1);
1071 }
1072 
1073 /**
1074  * vio_match_device: - Tell if a VIO device has a matching
1075  *                      VIO device id structure.
1076  * @ids:        array of VIO device id structures to search in
1077  * @dev:        the VIO device structure to match against
1078  *
1079  * Used by a driver to check whether a VIO device present in the
1080  * system is in its list of supported devices. Returns the matching
1081  * vio_device_id structure or NULL if there is no match.
1082  */
1083 static const struct vio_device_id *vio_match_device(
1084                 const struct vio_device_id *ids, const struct vio_dev *dev)
1085 {
1086         while (ids->type[0] != '\0') {
1087                 if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
1088                     of_device_is_compatible(dev->dev.archdata.of_node,
1089                                          ids->compat))
1090                         return ids;
1091                 ids++;
1092         }
1093         return NULL;
1094 }
1095 
1096 /*
1097  * Convert from struct device to struct vio_dev and pass to driver.
1098  * dev->driver has already been set by generic code because vio_bus_match
1099  * succeeded.
1100  */
1101 static int vio_bus_probe(struct device *dev)
1102 {
1103         struct vio_dev *viodev = to_vio_dev(dev);
1104         struct vio_driver *viodrv = to_vio_driver(dev->driver);
1105         const struct vio_device_id *id;
1106         int error = -ENODEV;
1107 
1108         if (!viodrv->probe)
1109                 return error;
1110 
1111         id = vio_match_device(viodrv->id_table, viodev);
1112         if (id) {
1113                 memset(&viodev->cmo, 0, sizeof(viodev->cmo));
1114                 if (firmware_has_feature(FW_FEATURE_CMO)) {
1115                         error = vio_cmo_bus_probe(viodev);
1116                         if (error)
1117                                 return error;
1118                 }
1119                 error = viodrv->probe(viodev, id);
1120                 if (error && firmware_has_feature(FW_FEATURE_CMO))
1121                         vio_cmo_bus_remove(viodev);
1122         }
1123 
1124         return error;
1125 }
1126 
1127 /* convert from struct device to struct vio_dev and pass to driver. */
1128 static int vio_bus_remove(struct device *dev)
1129 {
1130         struct vio_dev *viodev = to_vio_dev(dev);
1131         struct vio_driver *viodrv = to_vio_driver(dev->driver);
1132         struct device *devptr;
1133         int ret = 1;
1134 
1135         /*
1136          * Hold a reference to the device after the remove function is called
1137          * to allow for CMO accounting cleanup for the device.
1138          */
1139         devptr = get_device(dev);
1140 
1141         if (viodrv->remove)
1142                 ret = viodrv->remove(viodev);
1143 
1144         if (!ret && firmware_has_feature(FW_FEATURE_CMO))
1145                 vio_cmo_bus_remove(viodev);
1146 
1147         put_device(devptr);
1148         return ret;
1149 }
1150 
1151 /**
1152  * vio_register_driver: - Register a new vio driver
1153  * @drv:        The vio_driver structure to be registered.
1154  */
1155 int vio_register_driver(struct vio_driver *viodrv)
1156 {
1157         printk(KERN_DEBUG "%s: driver %s registering\n", __func__,
1158                 viodrv->driver.name);
1159 
1160         /* fill in 'struct driver' fields */
1161         viodrv->driver.bus = &vio_bus_type;
1162 
1163         return driver_register(&viodrv->driver);
1164 }
1165 EXPORT_SYMBOL(vio_register_driver);
1166 
1167 /**
1168  * vio_unregister_driver - Remove registration of vio driver.
1169  * @driver:     The vio_driver struct to be removed form registration
1170  */
1171 void vio_unregister_driver(struct vio_driver *viodrv)
1172 {
1173         driver_unregister(&viodrv->driver);
1174 }
1175 EXPORT_SYMBOL(vio_unregister_driver);
1176 
1177 /* vio_dev refcount hit 0 */
1178 static void __devinit vio_dev_release(struct device *dev)
1179 {
1180         /* XXX should free TCE table */
1181         of_node_put(dev->archdata.of_node);
1182         kfree(to_vio_dev(dev));
1183 }
1184 
1185 /**
1186  * vio_register_device_node: - Register a new vio device.
1187  * @of_node:    The OF node for this device.
1188  *
1189  * Creates and initializes a vio_dev structure from the data in
1190  * of_node and adds it to the list of virtual devices.
1191  * Returns a pointer to the created vio_dev or NULL if node has
1192  * NULL device_type or compatible fields.
1193  */
1194 struct vio_dev *vio_register_device_node(struct device_node *of_node)
1195 {
1196         struct vio_dev *viodev;
1197         const unsigned int *unit_address;
1198 
1199         /* we need the 'device_type' property, in order to match with drivers */
1200         if (of_node->type == NULL) {
1201                 printk(KERN_WARNING "%s: node %s missing 'device_type'\n",
1202                                 __func__,
1203                                 of_node->name ? of_node->name : "<unknown>");
1204                 return NULL;
1205         }
1206 
1207         unit_address = of_get_property(of_node, "reg", NULL);
1208         if (unit_address == NULL) {
1209                 printk(KERN_WARNING "%s: node %s missing 'reg'\n",
1210                                 __func__,
1211                                 of_node->name ? of_node->name : "<unknown>");
1212                 return NULL;
1213         }
1214 
1215         /* allocate a vio_dev for this node */
1216         viodev = kzalloc(sizeof(struct vio_dev), GFP_KERNEL);
1217         if (viodev == NULL)
1218                 return NULL;
1219 
1220         viodev->irq = irq_of_parse_and_map(of_node, 0);
1221 
1222         dev_set_name(&viodev->dev, "%x", *unit_address);
1223         viodev->name = of_node->name;
1224         viodev->type = of_node->type;
1225         viodev->unit_address = *unit_address;
1226         if (firmware_has_feature(FW_FEATURE_ISERIES)) {
1227                 unit_address = of_get_property(of_node,
1228                                 "linux,unit_address", NULL);
1229                 if (unit_address != NULL)
1230                         viodev->unit_address = *unit_address;
1231         }
1232         viodev->dev.archdata.of_node = of_node_get(of_node);
1233 
1234         if (firmware_has_feature(FW_FEATURE_CMO))
1235                 vio_cmo_set_dma_ops(viodev);
1236         else
1237                 viodev->dev.archdata.dma_ops = &dma_iommu_ops;
1238         set_iommu_table_base(&viodev->dev, vio_build_iommu_table(viodev));
1239         set_dev_node(&viodev->dev, of_node_to_nid(of_node));
1240 
1241         /* init generic 'struct device' fields: */
1242         viodev->dev.parent = &vio_bus_device.dev;
1243         viodev->dev.bus = &vio_bus_type;
1244         viodev->dev.release = vio_dev_release;
1245 
1246         /* register with generic device framework */
1247         if (device_register(&viodev->dev)) {
1248                 printk(KERN_ERR "%s: failed to register device %s\n",
1249                                 __func__, dev_name(&viodev->dev));
1250                 /* XXX free TCE table */
1251                 kfree(viodev);
1252                 return NULL;
1253         }
1254 
1255         return viodev;
1256 }
1257 EXPORT_SYMBOL(vio_register_device_node);
1258 
1259 /**
1260  * vio_bus_init: - Initialize the virtual IO bus
1261  */
1262 static int __init vio_bus_init(void)
1263 {
1264         int err;
1265         struct device_node *node_vroot;
1266 
1267         if (firmware_has_feature(FW_FEATURE_CMO))
1268                 vio_cmo_sysfs_init();
1269 
1270         err = bus_register(&vio_bus_type);
1271         if (err) {
1272                 printk(KERN_ERR "failed to register VIO bus\n");
1273                 return err;
1274         }
1275 
1276         /*
1277          * The fake parent of all vio devices, just to give us
1278          * a nice directory
1279          */
1280         err = device_register(&vio_bus_device.dev);
1281         if (err) {
1282                 printk(KERN_WARNING "%s: device_register returned %i\n",
1283                                 __func__, err);
1284                 return err;
1285         }
1286 
1287         if (firmware_has_feature(FW_FEATURE_CMO))
1288                 vio_cmo_bus_init();
1289 
1290         node_vroot = of_find_node_by_name(NULL, "vdevice");
1291         if (node_vroot) {
1292                 struct device_node *of_node;
1293 
1294                 /*
1295                  * Create struct vio_devices for each virtual device in
1296                  * the device tree. Drivers will associate with them later.
1297                  */
1298                 for (of_node = node_vroot->child; of_node != NULL;
1299                                 of_node = of_node->sibling)
1300                         vio_register_device_node(of_node);
1301                 of_node_put(node_vroot);
1302         }
1303 
1304         return 0;
1305 }
1306 __initcall(vio_bus_init);
1307 
1308 static ssize_t name_show(struct device *dev,
1309                 struct device_attribute *attr, char *buf)
1310 {
1311         return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
1312 }
1313 
1314 static ssize_t devspec_show(struct device *dev,
1315                 struct device_attribute *attr, char *buf)
1316 {
1317         struct device_node *of_node = dev->archdata.of_node;
1318 
1319         return sprintf(buf, "%s\n", of_node ? of_node->full_name : "none");
1320 }
1321 
1322 static struct device_attribute vio_dev_attrs[] = {
1323         __ATTR_RO(name),
1324         __ATTR_RO(devspec),
1325         __ATTR_NULL
1326 };
1327 
1328 void __devinit vio_unregister_device(struct vio_dev *viodev)
1329 {
1330         device_unregister(&viodev->dev);
1331 }
1332 EXPORT_SYMBOL(vio_unregister_device);
1333 
1334 static int vio_bus_match(struct device *dev, struct device_driver *drv)
1335 {
1336         const struct vio_dev *vio_dev = to_vio_dev(dev);
1337         struct vio_driver *vio_drv = to_vio_driver(drv);
1338         const struct vio_device_id *ids = vio_drv->id_table;
1339 
1340         return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
1341 }
1342 
1343 static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
1344 {
1345         const struct vio_dev *vio_dev = to_vio_dev(dev);
1346         struct device_node *dn;
1347         const char *cp;
1348 
1349         dn = dev->archdata.of_node;
1350         if (!dn)
1351                 return -ENODEV;
1352         cp = of_get_property(dn, "compatible", NULL);
1353         if (!cp)
1354                 return -ENODEV;
1355 
1356         add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
1357         return 0;
1358 }
1359 
1360 static struct bus_type vio_bus_type = {
1361         .name = "vio",
1362         .dev_attrs = vio_dev_attrs,
1363         .uevent = vio_hotplug,
1364         .match = vio_bus_match,
1365         .probe = vio_bus_probe,
1366         .remove = vio_bus_remove,
1367 };
1368 
1369 /**
1370  * vio_get_attribute: - get attribute for virtual device
1371  * @vdev:       The vio device to get property.
1372  * @which:      The property/attribute to be extracted.
1373  * @length:     Pointer to length of returned data size (unused if NULL).
1374  *
1375  * Calls prom.c's of_get_property() to return the value of the
1376  * attribute specified by @which
1377 */
1378 const void *vio_get_attribute(struct vio_dev *vdev, char *which, int *length)
1379 {
1380         return of_get_property(vdev->dev.archdata.of_node, which, length);
1381 }
1382 EXPORT_SYMBOL(vio_get_attribute);
1383 
1384 #ifdef CONFIG_PPC_PSERIES
1385 /* vio_find_name() - internal because only vio.c knows how we formatted the
1386  * kobject name
1387  */
1388 static struct vio_dev *vio_find_name(const char *name)
1389 {
1390         struct device *found;
1391 
1392         found = bus_find_device_by_name(&vio_bus_type, NULL, name);
1393         if (!found)
1394                 return NULL;
1395 
1396         return to_vio_dev(found);
1397 }
1398 
1399 /**
1400  * vio_find_node - find an already-registered vio_dev
1401  * @vnode: device_node of the virtual device we're looking for
1402  */
1403 struct vio_dev *vio_find_node(struct device_node *vnode)
1404 {
1405         const uint32_t *unit_address;
1406         char kobj_name[20];
1407 
1408         /* construct the kobject name from the device node */
1409         unit_address = of_get_property(vnode, "reg", NULL);
1410         if (!unit_address)
1411                 return NULL;
1412         snprintf(kobj_name, sizeof(kobj_name), "%x", *unit_address);
1413 
1414         return vio_find_name(kobj_name);
1415 }
1416 EXPORT_SYMBOL(vio_find_node);
1417 
1418 int vio_enable_interrupts(struct vio_dev *dev)
1419 {
1420         int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
1421         if (rc != H_SUCCESS)
1422                 printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
1423         return rc;
1424 }
1425 EXPORT_SYMBOL(vio_enable_interrupts);
1426 
1427 int vio_disable_interrupts(struct vio_dev *dev)
1428 {
1429         int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
1430         if (rc != H_SUCCESS)
1431                 printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
1432         return rc;
1433 }
1434 EXPORT_SYMBOL(vio_disable_interrupts);
1435 #endif /* CONFIG_PPC_PSERIES */
1436 

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