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TOMOYO Linux Cross Reference
Linux/arch/powerpc/platforms/pseries/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/cpu.h>
 18 #include <linux/types.h>
 19 #include <linux/delay.h>
 20 #include <linux/stat.h>
 21 #include <linux/device.h>
 22 #include <linux/init.h>
 23 #include <linux/slab.h>
 24 #include <linux/console.h>
 25 #include <linux/export.h>
 26 #include <linux/mm.h>
 27 #include <linux/dma-mapping.h>
 28 #include <linux/kobject.h>
 29 
 30 #include <asm/iommu.h>
 31 #include <asm/dma.h>
 32 #include <asm/vio.h>
 33 #include <asm/prom.h>
 34 #include <asm/firmware.h>
 35 #include <asm/tce.h>
 36 #include <asm/page.h>
 37 #include <asm/hvcall.h>
 38 
 39 static struct vio_dev vio_bus_device  = { /* fake "parent" device */
 40         .name = "vio",
 41         .type = "",
 42         .dev.init_name = "vio",
 43         .dev.bus = &vio_bus_type,
 44 };
 45 
 46 #ifdef CONFIG_PPC_SMLPAR
 47 /**
 48  * vio_cmo_pool - A pool of IO memory for CMO use
 49  *
 50  * @size: The size of the pool in bytes
 51  * @free: The amount of free memory in the pool
 52  */
 53 struct vio_cmo_pool {
 54         size_t size;
 55         size_t free;
 56 };
 57 
 58 /* How many ms to delay queued balance work */
 59 #define VIO_CMO_BALANCE_DELAY 100
 60 
 61 /* Portion out IO memory to CMO devices by this chunk size */
 62 #define VIO_CMO_BALANCE_CHUNK 131072
 63 
 64 /**
 65  * vio_cmo_dev_entry - A device that is CMO-enabled and requires entitlement
 66  *
 67  * @vio_dev: struct vio_dev pointer
 68  * @list: pointer to other devices on bus that are being tracked
 69  */
 70 struct vio_cmo_dev_entry {
 71         struct vio_dev *viodev;
 72         struct list_head list;
 73 };
 74 
 75 /**
 76  * vio_cmo - VIO bus accounting structure for CMO entitlement
 77  *
 78  * @lock: spinlock for entire structure
 79  * @balance_q: work queue for balancing system entitlement
 80  * @device_list: list of CMO-enabled devices requiring entitlement
 81  * @entitled: total system entitlement in bytes
 82  * @reserve: pool of memory from which devices reserve entitlement, incl. spare
 83  * @excess: pool of excess entitlement not needed for device reserves or spare
 84  * @spare: IO memory for device hotplug functionality
 85  * @min: minimum necessary for system operation
 86  * @desired: desired memory for system operation
 87  * @curr: bytes currently allocated
 88  * @high: high water mark for IO data usage
 89  */
 90 static struct vio_cmo {
 91         spinlock_t lock;
 92         struct delayed_work balance_q;
 93         struct list_head device_list;
 94         size_t entitled;
 95         struct vio_cmo_pool reserve;
 96         struct vio_cmo_pool excess;
 97         size_t spare;
 98         size_t min;
 99         size_t desired;
100         size_t curr;
101         size_t high;
102 } vio_cmo;
103 
104 /**
105  * vio_cmo_OF_devices - Count the number of OF devices that have DMA windows
106  */
107 static int vio_cmo_num_OF_devs(void)
108 {
109         struct device_node *node_vroot;
110         int count = 0;
111 
112         /*
113          * Count the number of vdevice entries with an
114          * ibm,my-dma-window OF property
115          */
116         node_vroot = of_find_node_by_name(NULL, "vdevice");
117         if (node_vroot) {
118                 struct device_node *of_node;
119                 struct property *prop;
120 
121                 for_each_child_of_node(node_vroot, of_node) {
122                         prop = of_find_property(of_node, "ibm,my-dma-window",
123                                                NULL);
124                         if (prop)
125                                 count++;
126                 }
127         }
128         of_node_put(node_vroot);
129         return count;
130 }
131 
132 /**
133  * vio_cmo_alloc - allocate IO memory for CMO-enable devices
134  *
135  * @viodev: VIO device requesting IO memory
136  * @size: size of allocation requested
137  *
138  * Allocations come from memory reserved for the devices and any excess
139  * IO memory available to all devices.  The spare pool used to service
140  * hotplug must be equal to %VIO_CMO_MIN_ENT for the excess pool to be
141  * made available.
142  *
143  * Return codes:
144  *  0 for successful allocation and -ENOMEM for a failure
145  */
146 static inline int vio_cmo_alloc(struct vio_dev *viodev, size_t size)
147 {
148         unsigned long flags;
149         size_t reserve_free = 0;
150         size_t excess_free = 0;
151         int ret = -ENOMEM;
152 
153         spin_lock_irqsave(&vio_cmo.lock, flags);
154 
155         /* Determine the amount of free entitlement available in reserve */
156         if (viodev->cmo.entitled > viodev->cmo.allocated)
157                 reserve_free = viodev->cmo.entitled - viodev->cmo.allocated;
158 
159         /* If spare is not fulfilled, the excess pool can not be used. */
160         if (vio_cmo.spare >= VIO_CMO_MIN_ENT)
161                 excess_free = vio_cmo.excess.free;
162 
163         /* The request can be satisfied */
164         if ((reserve_free + excess_free) >= size) {
165                 vio_cmo.curr += size;
166                 if (vio_cmo.curr > vio_cmo.high)
167                         vio_cmo.high = vio_cmo.curr;
168                 viodev->cmo.allocated += size;
169                 size -= min(reserve_free, size);
170                 vio_cmo.excess.free -= size;
171                 ret = 0;
172         }
173 
174         spin_unlock_irqrestore(&vio_cmo.lock, flags);
175         return ret;
176 }
177 
178 /**
179  * vio_cmo_dealloc - deallocate IO memory from CMO-enable devices
180  * @viodev: VIO device freeing IO memory
181  * @size: size of deallocation
182  *
183  * IO memory is freed by the device back to the correct memory pools.
184  * The spare pool is replenished first from either memory pool, then
185  * the reserve pool is used to reduce device entitlement, the excess
186  * pool is used to increase the reserve pool toward the desired entitlement
187  * target, and then the remaining memory is returned to the pools.
188  *
189  */
190 static inline void vio_cmo_dealloc(struct vio_dev *viodev, size_t size)
191 {
192         unsigned long flags;
193         size_t spare_needed = 0;
194         size_t excess_freed = 0;
195         size_t reserve_freed = size;
196         size_t tmp;
197         int balance = 0;
198 
199         spin_lock_irqsave(&vio_cmo.lock, flags);
200         vio_cmo.curr -= size;
201 
202         /* Amount of memory freed from the excess pool */
203         if (viodev->cmo.allocated > viodev->cmo.entitled) {
204                 excess_freed = min(reserve_freed, (viodev->cmo.allocated -
205                                                    viodev->cmo.entitled));
206                 reserve_freed -= excess_freed;
207         }
208 
209         /* Remove allocation from device */
210         viodev->cmo.allocated -= (reserve_freed + excess_freed);
211 
212         /* Spare is a subset of the reserve pool, replenish it first. */
213         spare_needed = VIO_CMO_MIN_ENT - vio_cmo.spare;
214 
215         /*
216          * Replenish the spare in the reserve pool from the excess pool.
217          * This moves entitlement into the reserve pool.
218          */
219         if (spare_needed && excess_freed) {
220                 tmp = min(excess_freed, spare_needed);
221                 vio_cmo.excess.size -= tmp;
222                 vio_cmo.reserve.size += tmp;
223                 vio_cmo.spare += tmp;
224                 excess_freed -= tmp;
225                 spare_needed -= tmp;
226                 balance = 1;
227         }
228 
229         /*
230          * Replenish the spare in the reserve pool from the reserve pool.
231          * This removes entitlement from the device down to VIO_CMO_MIN_ENT,
232          * if needed, and gives it to the spare pool. The amount of used
233          * memory in this pool does not change.
234          */
235         if (spare_needed && reserve_freed) {
236                 tmp = min3(spare_needed, reserve_freed, (viodev->cmo.entitled - VIO_CMO_MIN_ENT));
237 
238                 vio_cmo.spare += tmp;
239                 viodev->cmo.entitled -= tmp;
240                 reserve_freed -= tmp;
241                 spare_needed -= tmp;
242                 balance = 1;
243         }
244 
245         /*
246          * Increase the reserve pool until the desired allocation is met.
247          * Move an allocation freed from the excess pool into the reserve
248          * pool and schedule a balance operation.
249          */
250         if (excess_freed && (vio_cmo.desired > vio_cmo.reserve.size)) {
251                 tmp = min(excess_freed, (vio_cmo.desired - vio_cmo.reserve.size));
252 
253                 vio_cmo.excess.size -= tmp;
254                 vio_cmo.reserve.size += tmp;
255                 excess_freed -= tmp;
256                 balance = 1;
257         }
258 
259         /* Return memory from the excess pool to that pool */
260         if (excess_freed)
261                 vio_cmo.excess.free += excess_freed;
262 
263         if (balance)
264                 schedule_delayed_work(&vio_cmo.balance_q, VIO_CMO_BALANCE_DELAY);
265         spin_unlock_irqrestore(&vio_cmo.lock, flags);
266 }
267 
268 /**
269  * vio_cmo_entitlement_update - Manage system entitlement changes
270  *
271  * @new_entitlement: new system entitlement to attempt to accommodate
272  *
273  * Increases in entitlement will be used to fulfill the spare entitlement
274  * and the rest is given to the excess pool.  Decreases, if they are
275  * possible, come from the excess pool and from unused device entitlement
276  *
277  * Returns: 0 on success, -ENOMEM when change can not be made
278  */
279 int vio_cmo_entitlement_update(size_t new_entitlement)
280 {
281         struct vio_dev *viodev;
282         struct vio_cmo_dev_entry *dev_ent;
283         unsigned long flags;
284         size_t avail, delta, tmp;
285 
286         spin_lock_irqsave(&vio_cmo.lock, flags);
287 
288         /* Entitlement increases */
289         if (new_entitlement > vio_cmo.entitled) {
290                 delta = new_entitlement - vio_cmo.entitled;
291 
292                 /* Fulfill spare allocation */
293                 if (vio_cmo.spare < VIO_CMO_MIN_ENT) {
294                         tmp = min(delta, (VIO_CMO_MIN_ENT - vio_cmo.spare));
295                         vio_cmo.spare += tmp;
296                         vio_cmo.reserve.size += tmp;
297                         delta -= tmp;
298                 }
299 
300                 /* Remaining new allocation goes to the excess pool */
301                 vio_cmo.entitled += delta;
302                 vio_cmo.excess.size += delta;
303                 vio_cmo.excess.free += delta;
304 
305                 goto out;
306         }
307 
308         /* Entitlement decreases */
309         delta = vio_cmo.entitled - new_entitlement;
310         avail = vio_cmo.excess.free;
311 
312         /*
313          * Need to check how much unused entitlement each device can
314          * sacrifice to fulfill entitlement change.
315          */
316         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
317                 if (avail >= delta)
318                         break;
319 
320                 viodev = dev_ent->viodev;
321                 if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
322                     (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
323                                 avail += viodev->cmo.entitled -
324                                          max_t(size_t, viodev->cmo.allocated,
325                                                VIO_CMO_MIN_ENT);
326         }
327 
328         if (delta <= avail) {
329                 vio_cmo.entitled -= delta;
330 
331                 /* Take entitlement from the excess pool first */
332                 tmp = min(vio_cmo.excess.free, delta);
333                 vio_cmo.excess.size -= tmp;
334                 vio_cmo.excess.free -= tmp;
335                 delta -= tmp;
336 
337                 /*
338                  * Remove all but VIO_CMO_MIN_ENT bytes from devices
339                  * until entitlement change is served
340                  */
341                 list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
342                         if (!delta)
343                                 break;
344 
345                         viodev = dev_ent->viodev;
346                         tmp = 0;
347                         if ((viodev->cmo.entitled > viodev->cmo.allocated) &&
348                             (viodev->cmo.entitled > VIO_CMO_MIN_ENT))
349                                 tmp = viodev->cmo.entitled -
350                                       max_t(size_t, viodev->cmo.allocated,
351                                             VIO_CMO_MIN_ENT);
352                         viodev->cmo.entitled -= min(tmp, delta);
353                         delta -= min(tmp, delta);
354                 }
355         } else {
356                 spin_unlock_irqrestore(&vio_cmo.lock, flags);
357                 return -ENOMEM;
358         }
359 
360 out:
361         schedule_delayed_work(&vio_cmo.balance_q, 0);
362         spin_unlock_irqrestore(&vio_cmo.lock, flags);
363         return 0;
364 }
365 
366 /**
367  * vio_cmo_balance - Balance entitlement among devices
368  *
369  * @work: work queue structure for this operation
370  *
371  * Any system entitlement above the minimum needed for devices, or
372  * already allocated to devices, can be distributed to the devices.
373  * The list of devices is iterated through to recalculate the desired
374  * entitlement level and to determine how much entitlement above the
375  * minimum entitlement is allocated to devices.
376  *
377  * Small chunks of the available entitlement are given to devices until
378  * their requirements are fulfilled or there is no entitlement left to give.
379  * Upon completion sizes of the reserve and excess pools are calculated.
380  *
381  * The system minimum entitlement level is also recalculated here.
382  * Entitlement will be reserved for devices even after vio_bus_remove to
383  * accommodate reloading the driver.  The OF tree is walked to count the
384  * number of devices present and this will remove entitlement for devices
385  * that have actually left the system after having vio_bus_remove called.
386  */
387 static void vio_cmo_balance(struct work_struct *work)
388 {
389         struct vio_cmo *cmo;
390         struct vio_dev *viodev;
391         struct vio_cmo_dev_entry *dev_ent;
392         unsigned long flags;
393         size_t avail = 0, level, chunk, need;
394         int devcount = 0, fulfilled;
395 
396         cmo = container_of(work, struct vio_cmo, balance_q.work);
397 
398         spin_lock_irqsave(&vio_cmo.lock, flags);
399 
400         /* Calculate minimum entitlement and fulfill spare */
401         cmo->min = vio_cmo_num_OF_devs() * VIO_CMO_MIN_ENT;
402         BUG_ON(cmo->min > cmo->entitled);
403         cmo->spare = min_t(size_t, VIO_CMO_MIN_ENT, (cmo->entitled - cmo->min));
404         cmo->min += cmo->spare;
405         cmo->desired = cmo->min;
406 
407         /*
408          * Determine how much entitlement is available and reset device
409          * entitlements
410          */
411         avail = cmo->entitled - cmo->spare;
412         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
413                 viodev = dev_ent->viodev;
414                 devcount++;
415                 viodev->cmo.entitled = VIO_CMO_MIN_ENT;
416                 cmo->desired += (viodev->cmo.desired - VIO_CMO_MIN_ENT);
417                 avail -= max_t(size_t, viodev->cmo.allocated, VIO_CMO_MIN_ENT);
418         }
419 
420         /*
421          * Having provided each device with the minimum entitlement, loop
422          * over the devices portioning out the remaining entitlement
423          * until there is nothing left.
424          */
425         level = VIO_CMO_MIN_ENT;
426         while (avail) {
427                 fulfilled = 0;
428                 list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
429                         viodev = dev_ent->viodev;
430 
431                         if (viodev->cmo.desired <= level) {
432                                 fulfilled++;
433                                 continue;
434                         }
435 
436                         /*
437                          * Give the device up to VIO_CMO_BALANCE_CHUNK
438                          * bytes of entitlement, but do not exceed the
439                          * desired level of entitlement for the device.
440                          */
441                         chunk = min_t(size_t, avail, VIO_CMO_BALANCE_CHUNK);
442                         chunk = min(chunk, (viodev->cmo.desired -
443                                             viodev->cmo.entitled));
444                         viodev->cmo.entitled += chunk;
445 
446                         /*
447                          * If the memory for this entitlement increase was
448                          * already allocated to the device it does not come
449                          * from the available pool being portioned out.
450                          */
451                         need = max(viodev->cmo.allocated, viodev->cmo.entitled)-
452                                max(viodev->cmo.allocated, level);
453                         avail -= need;
454 
455                 }
456                 if (fulfilled == devcount)
457                         break;
458                 level += VIO_CMO_BALANCE_CHUNK;
459         }
460 
461         /* Calculate new reserve and excess pool sizes */
462         cmo->reserve.size = cmo->min;
463         cmo->excess.free = 0;
464         cmo->excess.size = 0;
465         need = 0;
466         list_for_each_entry(dev_ent, &vio_cmo.device_list, list) {
467                 viodev = dev_ent->viodev;
468                 /* Calculated reserve size above the minimum entitlement */
469                 if (viodev->cmo.entitled)
470                         cmo->reserve.size += (viodev->cmo.entitled -
471                                               VIO_CMO_MIN_ENT);
472                 /* Calculated used excess entitlement */
473                 if (viodev->cmo.allocated > viodev->cmo.entitled)
474                         need += viodev->cmo.allocated - viodev->cmo.entitled;
475         }
476         cmo->excess.size = cmo->entitled - cmo->reserve.size;
477         cmo->excess.free = cmo->excess.size - need;
478 
479         cancel_delayed_work(to_delayed_work(work));
480         spin_unlock_irqrestore(&vio_cmo.lock, flags);
481 }
482 
483 static void *vio_dma_iommu_alloc_coherent(struct device *dev, size_t size,
484                                           dma_addr_t *dma_handle, gfp_t flag,
485                                           unsigned long attrs)
486 {
487         struct vio_dev *viodev = to_vio_dev(dev);
488         void *ret;
489 
490         if (vio_cmo_alloc(viodev, roundup(size, PAGE_SIZE))) {
491                 atomic_inc(&viodev->cmo.allocs_failed);
492                 return NULL;
493         }
494 
495         ret = dma_iommu_ops.alloc(dev, size, dma_handle, flag, attrs);
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 
504 static 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         dma_iommu_ops.free(dev, size, vaddr, dma_handle, attrs);
511 
512         vio_cmo_dealloc(viodev, roundup(size, PAGE_SIZE));
513 }
514 
515 static dma_addr_t vio_dma_iommu_map_page(struct device *dev, struct page *page,
516                                          unsigned long offset, size_t size,
517                                          enum dma_data_direction direction,
518                                          unsigned long attrs)
519 {
520         struct vio_dev *viodev = to_vio_dev(dev);
521         struct iommu_table *tbl;
522         dma_addr_t ret = IOMMU_MAPPING_ERROR;
523 
524         tbl = get_iommu_table_base(dev);
525         if (vio_cmo_alloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)))) {
526                 atomic_inc(&viodev->cmo.allocs_failed);
527                 return ret;
528         }
529 
530         ret = dma_iommu_ops.map_page(dev, page, offset, size, direction, attrs);
531         if (unlikely(dma_mapping_error(dev, ret))) {
532                 vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
533                 atomic_inc(&viodev->cmo.allocs_failed);
534         }
535 
536         return ret;
537 }
538 
539 static void vio_dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle,
540                                      size_t size,
541                                      enum dma_data_direction direction,
542                                      unsigned long attrs)
543 {
544         struct vio_dev *viodev = to_vio_dev(dev);
545         struct iommu_table *tbl;
546 
547         tbl = get_iommu_table_base(dev);
548         dma_iommu_ops.unmap_page(dev, dma_handle, size, direction, attrs);
549 
550         vio_cmo_dealloc(viodev, roundup(size, IOMMU_PAGE_SIZE(tbl)));
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                                 unsigned long attrs)
556 {
557         struct vio_dev *viodev = to_vio_dev(dev);
558         struct iommu_table *tbl;
559         struct scatterlist *sgl;
560         int ret, count;
561         size_t alloc_size = 0;
562 
563         tbl = get_iommu_table_base(dev);
564         for_each_sg(sglist, sgl, nelems, count)
565                 alloc_size += roundup(sgl->length, IOMMU_PAGE_SIZE(tbl));
566 
567         if (vio_cmo_alloc(viodev, alloc_size)) {
568                 atomic_inc(&viodev->cmo.allocs_failed);
569                 return 0;
570         }
571 
572         ret = dma_iommu_ops.map_sg(dev, sglist, nelems, direction, attrs);
573 
574         if (unlikely(!ret)) {
575                 vio_cmo_dealloc(viodev, alloc_size);
576                 atomic_inc(&viodev->cmo.allocs_failed);
577                 return ret;
578         }
579 
580         for_each_sg(sglist, sgl, ret, count)
581                 alloc_size -= roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
582         if (alloc_size)
583                 vio_cmo_dealloc(viodev, alloc_size);
584 
585         return ret;
586 }
587 
588 static void vio_dma_iommu_unmap_sg(struct device *dev,
589                 struct scatterlist *sglist, int nelems,
590                 enum dma_data_direction direction,
591                 unsigned long attrs)
592 {
593         struct vio_dev *viodev = to_vio_dev(dev);
594         struct iommu_table *tbl;
595         struct scatterlist *sgl;
596         size_t alloc_size = 0;
597         int count;
598 
599         tbl = get_iommu_table_base(dev);
600         for_each_sg(sglist, sgl, nelems, count)
601                 alloc_size += roundup(sgl->dma_length, IOMMU_PAGE_SIZE(tbl));
602 
603         dma_iommu_ops.unmap_sg(dev, sglist, nelems, direction, attrs);
604 
605         vio_cmo_dealloc(viodev, alloc_size);
606 }
607 
608 static int vio_dma_iommu_dma_supported(struct device *dev, u64 mask)
609 {
610         return dma_iommu_ops.dma_supported(dev, mask);
611 }
612 
613 static u64 vio_dma_get_required_mask(struct device *dev)
614 {
615         return dma_iommu_ops.get_required_mask(dev);
616 }
617 
618 static const struct dma_map_ops vio_dma_mapping_ops = {
619         .alloc             = vio_dma_iommu_alloc_coherent,
620         .free              = vio_dma_iommu_free_coherent,
621         .mmap              = dma_nommu_mmap_coherent,
622         .map_sg            = vio_dma_iommu_map_sg,
623         .unmap_sg          = vio_dma_iommu_unmap_sg,
624         .map_page          = vio_dma_iommu_map_page,
625         .unmap_page        = vio_dma_iommu_unmap_page,
626         .dma_supported     = vio_dma_iommu_dma_supported,
627         .get_required_mask = vio_dma_get_required_mask,
628         .mapping_error     = dma_iommu_mapping_error,
629 };
630 
631 /**
632  * vio_cmo_set_dev_desired - Set desired entitlement for a device
633  *
634  * @viodev: struct vio_dev for device to alter
635  * @desired: new desired entitlement level in bytes
636  *
637  * For use by devices to request a change to their entitlement at runtime or
638  * through sysfs.  The desired entitlement level is changed and a balancing
639  * of system resources is scheduled to run in the future.
640  */
641 void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired)
642 {
643         unsigned long flags;
644         struct vio_cmo_dev_entry *dev_ent;
645         int found = 0;
646 
647         if (!firmware_has_feature(FW_FEATURE_CMO))
648                 return;
649 
650         spin_lock_irqsave(&vio_cmo.lock, flags);
651         if (desired < VIO_CMO_MIN_ENT)
652                 desired = VIO_CMO_MIN_ENT;
653 
654         /*
655          * Changes will not be made for devices not in the device list.
656          * If it is not in the device list, then no driver is loaded
657          * for the device and it can not receive entitlement.
658          */
659         list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
660                 if (viodev == dev_ent->viodev) {
661                         found = 1;
662                         break;
663                 }
664         if (!found) {
665                 spin_unlock_irqrestore(&vio_cmo.lock, flags);
666                 return;
667         }
668 
669         /* Increase/decrease in desired device entitlement */
670         if (desired >= viodev->cmo.desired) {
671                 /* Just bump the bus and device values prior to a balance*/
672                 vio_cmo.desired += desired - viodev->cmo.desired;
673                 viodev->cmo.desired = desired;
674         } else {
675                 /* Decrease bus and device values for desired entitlement */
676                 vio_cmo.desired -= viodev->cmo.desired - desired;
677                 viodev->cmo.desired = desired;
678                 /*
679                  * If less entitlement is desired than current entitlement, move
680                  * any reserve memory in the change region to the excess pool.
681                  */
682                 if (viodev->cmo.entitled > desired) {
683                         vio_cmo.reserve.size -= viodev->cmo.entitled - desired;
684                         vio_cmo.excess.size += viodev->cmo.entitled - desired;
685                         /*
686                          * If entitlement moving from the reserve pool to the
687                          * excess pool is currently unused, add to the excess
688                          * free counter.
689                          */
690                         if (viodev->cmo.allocated < viodev->cmo.entitled)
691                                 vio_cmo.excess.free += viodev->cmo.entitled -
692                                                        max(viodev->cmo.allocated, desired);
693                         viodev->cmo.entitled = desired;
694                 }
695         }
696         schedule_delayed_work(&vio_cmo.balance_q, 0);
697         spin_unlock_irqrestore(&vio_cmo.lock, flags);
698 }
699 
700 /**
701  * vio_cmo_bus_probe - Handle CMO specific bus probe activities
702  *
703  * @viodev - Pointer to struct vio_dev for device
704  *
705  * Determine the devices IO memory entitlement needs, attempting
706  * to satisfy the system minimum entitlement at first and scheduling
707  * a balance operation to take care of the rest at a later time.
708  *
709  * Returns: 0 on success, -EINVAL when device doesn't support CMO, and
710  *          -ENOMEM when entitlement is not available for device or
711  *          device entry.
712  *
713  */
714 static int vio_cmo_bus_probe(struct vio_dev *viodev)
715 {
716         struct vio_cmo_dev_entry *dev_ent;
717         struct device *dev = &viodev->dev;
718         struct iommu_table *tbl;
719         struct vio_driver *viodrv = to_vio_driver(dev->driver);
720         unsigned long flags;
721         size_t size;
722         bool dma_capable = false;
723 
724         tbl = get_iommu_table_base(dev);
725 
726         /* A device requires entitlement if it has a DMA window property */
727         switch (viodev->family) {
728         case VDEVICE:
729                 if (of_get_property(viodev->dev.of_node,
730                                         "ibm,my-dma-window", NULL))
731                         dma_capable = true;
732                 break;
733         case PFO:
734                 dma_capable = false;
735                 break;
736         default:
737                 dev_warn(dev, "unknown device family: %d\n", viodev->family);
738                 BUG();
739                 break;
740         }
741 
742         /* Configure entitlement for the device. */
743         if (dma_capable) {
744                 /* Check that the driver is CMO enabled and get desired DMA */
745                 if (!viodrv->get_desired_dma) {
746                         dev_err(dev, "%s: device driver does not support CMO\n",
747                                 __func__);
748                         return -EINVAL;
749                 }
750 
751                 viodev->cmo.desired =
752                         IOMMU_PAGE_ALIGN(viodrv->get_desired_dma(viodev), tbl);
753                 if (viodev->cmo.desired < VIO_CMO_MIN_ENT)
754                         viodev->cmo.desired = VIO_CMO_MIN_ENT;
755                 size = VIO_CMO_MIN_ENT;
756 
757                 dev_ent = kmalloc(sizeof(struct vio_cmo_dev_entry),
758                                   GFP_KERNEL);
759                 if (!dev_ent)
760                         return -ENOMEM;
761 
762                 dev_ent->viodev = viodev;
763                 spin_lock_irqsave(&vio_cmo.lock, flags);
764                 list_add(&dev_ent->list, &vio_cmo.device_list);
765         } else {
766                 viodev->cmo.desired = 0;
767                 size = 0;
768                 spin_lock_irqsave(&vio_cmo.lock, flags);
769         }
770 
771         /*
772          * If the needs for vio_cmo.min have not changed since they
773          * were last set, the number of devices in the OF tree has
774          * been constant and the IO memory for this is already in
775          * the reserve pool.
776          */
777         if (vio_cmo.min == ((vio_cmo_num_OF_devs() + 1) *
778                             VIO_CMO_MIN_ENT)) {
779                 /* Updated desired entitlement if device requires it */
780                 if (size)
781                         vio_cmo.desired += (viodev->cmo.desired -
782                                         VIO_CMO_MIN_ENT);
783         } else {
784                 size_t tmp;
785 
786                 tmp = vio_cmo.spare + vio_cmo.excess.free;
787                 if (tmp < size) {
788                         dev_err(dev, "%s: insufficient free "
789                                 "entitlement to add device. "
790                                 "Need %lu, have %lu\n", __func__,
791                                 size, (vio_cmo.spare + tmp));
792                         spin_unlock_irqrestore(&vio_cmo.lock, flags);
793                         return -ENOMEM;
794                 }
795 
796                 /* Use excess pool first to fulfill request */
797                 tmp = min(size, vio_cmo.excess.free);
798                 vio_cmo.excess.free -= tmp;
799                 vio_cmo.excess.size -= tmp;
800                 vio_cmo.reserve.size += tmp;
801 
802                 /* Use spare if excess pool was insufficient */
803                 vio_cmo.spare -= size - tmp;
804 
805                 /* Update bus accounting */
806                 vio_cmo.min += size;
807                 vio_cmo.desired += viodev->cmo.desired;
808         }
809         spin_unlock_irqrestore(&vio_cmo.lock, flags);
810         return 0;
811 }
812 
813 /**
814  * vio_cmo_bus_remove - Handle CMO specific bus removal activities
815  *
816  * @viodev - Pointer to struct vio_dev for device
817  *
818  * Remove the device from the cmo device list.  The minimum entitlement
819  * will be reserved for the device as long as it is in the system.  The
820  * rest of the entitlement the device had been allocated will be returned
821  * to the system.
822  */
823 static void vio_cmo_bus_remove(struct vio_dev *viodev)
824 {
825         struct vio_cmo_dev_entry *dev_ent;
826         unsigned long flags;
827         size_t tmp;
828 
829         spin_lock_irqsave(&vio_cmo.lock, flags);
830         if (viodev->cmo.allocated) {
831                 dev_err(&viodev->dev, "%s: device had %lu bytes of IO "
832                         "allocated after remove operation.\n",
833                         __func__, viodev->cmo.allocated);
834                 BUG();
835         }
836 
837         /*
838          * Remove the device from the device list being maintained for
839          * CMO enabled devices.
840          */
841         list_for_each_entry(dev_ent, &vio_cmo.device_list, list)
842                 if (viodev == dev_ent->viodev) {
843                         list_del(&dev_ent->list);
844                         kfree(dev_ent);
845                         break;
846                 }
847 
848         /*
849          * Devices may not require any entitlement and they do not need
850          * to be processed.  Otherwise, return the device's entitlement
851          * back to the pools.
852          */
853         if (viodev->cmo.entitled) {
854                 /*
855                  * This device has not yet left the OF tree, it's
856                  * minimum entitlement remains in vio_cmo.min and
857                  * vio_cmo.desired
858                  */
859                 vio_cmo.desired -= (viodev->cmo.desired - VIO_CMO_MIN_ENT);
860 
861                 /*
862                  * Save min allocation for device in reserve as long
863                  * as it exists in OF tree as determined by later
864                  * balance operation
865                  */
866                 viodev->cmo.entitled -= VIO_CMO_MIN_ENT;
867 
868                 /* Replenish spare from freed reserve pool */
869                 if (viodev->cmo.entitled && (vio_cmo.spare < VIO_CMO_MIN_ENT)) {
870                         tmp = min(viodev->cmo.entitled, (VIO_CMO_MIN_ENT -
871                                                          vio_cmo.spare));
872                         vio_cmo.spare += tmp;
873                         viodev->cmo.entitled -= tmp;
874                 }
875 
876                 /* Remaining reserve goes to excess pool */
877                 vio_cmo.excess.size += viodev->cmo.entitled;
878                 vio_cmo.excess.free += viodev->cmo.entitled;
879                 vio_cmo.reserve.size -= viodev->cmo.entitled;
880 
881                 /*
882                  * Until the device is removed it will keep a
883                  * minimum entitlement; this will guarantee that
884                  * a module unload/load will result in a success.
885                  */
886                 viodev->cmo.entitled = VIO_CMO_MIN_ENT;
887                 viodev->cmo.desired = VIO_CMO_MIN_ENT;
888                 atomic_set(&viodev->cmo.allocs_failed, 0);
889         }
890 
891         spin_unlock_irqrestore(&vio_cmo.lock, flags);
892 }
893 
894 static void vio_cmo_set_dma_ops(struct vio_dev *viodev)
895 {
896         set_dma_ops(&viodev->dev, &vio_dma_mapping_ops);
897 }
898 
899 /**
900  * vio_cmo_bus_init - CMO entitlement initialization at bus init time
901  *
902  * Set up the reserve and excess entitlement pools based on available
903  * system entitlement and the number of devices in the OF tree that
904  * require entitlement in the reserve pool.
905  */
906 static void vio_cmo_bus_init(void)
907 {
908         struct hvcall_mpp_data mpp_data;
909         int err;
910 
911         memset(&vio_cmo, 0, sizeof(struct vio_cmo));
912         spin_lock_init(&vio_cmo.lock);
913         INIT_LIST_HEAD(&vio_cmo.device_list);
914         INIT_DELAYED_WORK(&vio_cmo.balance_q, vio_cmo_balance);
915 
916         /* Get current system entitlement */
917         err = h_get_mpp(&mpp_data);
918 
919         /*
920          * On failure, continue with entitlement set to 0, will panic()
921          * later when spare is reserved.
922          */
923         if (err != H_SUCCESS) {
924                 printk(KERN_ERR "%s: unable to determine system IO "\
925                        "entitlement. (%d)\n", __func__, err);
926                 vio_cmo.entitled = 0;
927         } else {
928                 vio_cmo.entitled = mpp_data.entitled_mem;
929         }
930 
931         /* Set reservation and check against entitlement */
932         vio_cmo.spare = VIO_CMO_MIN_ENT;
933         vio_cmo.reserve.size = vio_cmo.spare;
934         vio_cmo.reserve.size += (vio_cmo_num_OF_devs() *
935                                  VIO_CMO_MIN_ENT);
936         if (vio_cmo.reserve.size > vio_cmo.entitled) {
937                 printk(KERN_ERR "%s: insufficient system entitlement\n",
938                        __func__);
939                 panic("%s: Insufficient system entitlement", __func__);
940         }
941 
942         /* Set the remaining accounting variables */
943         vio_cmo.excess.size = vio_cmo.entitled - vio_cmo.reserve.size;
944         vio_cmo.excess.free = vio_cmo.excess.size;
945         vio_cmo.min = vio_cmo.reserve.size;
946         vio_cmo.desired = vio_cmo.reserve.size;
947 }
948 
949 /* sysfs device functions and data structures for CMO */
950 
951 #define viodev_cmo_rd_attr(name)                                        \
952 static ssize_t cmo_##name##_show(struct device *dev,                    \
953                                         struct device_attribute *attr,  \
954                                          char *buf)                     \
955 {                                                                       \
956         return sprintf(buf, "%lu\n", to_vio_dev(dev)->cmo.name);        \
957 }
958 
959 static ssize_t cmo_allocs_failed_show(struct device *dev,
960                 struct device_attribute *attr, char *buf)
961 {
962         struct vio_dev *viodev = to_vio_dev(dev);
963         return sprintf(buf, "%d\n", atomic_read(&viodev->cmo.allocs_failed));
964 }
965 
966 static ssize_t cmo_allocs_failed_store(struct device *dev,
967                 struct device_attribute *attr, const char *buf, size_t count)
968 {
969         struct vio_dev *viodev = to_vio_dev(dev);
970         atomic_set(&viodev->cmo.allocs_failed, 0);
971         return count;
972 }
973 
974 static ssize_t cmo_desired_store(struct device *dev,
975                 struct device_attribute *attr, const char *buf, size_t count)
976 {
977         struct vio_dev *viodev = to_vio_dev(dev);
978         size_t new_desired;
979         int ret;
980 
981         ret = kstrtoul(buf, 10, &new_desired);
982         if (ret)
983                 return ret;
984 
985         vio_cmo_set_dev_desired(viodev, new_desired);
986         return count;
987 }
988 
989 viodev_cmo_rd_attr(desired);
990 viodev_cmo_rd_attr(entitled);
991 viodev_cmo_rd_attr(allocated);
992 
993 static ssize_t name_show(struct device *, struct device_attribute *, char *);
994 static ssize_t devspec_show(struct device *, struct device_attribute *, char *);
995 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
996                              char *buf);
997 
998 static struct device_attribute dev_attr_name;
999 static struct device_attribute dev_attr_devspec;
1000 static struct device_attribute dev_attr_modalias;
1001 
1002 static DEVICE_ATTR_RO(cmo_entitled);
1003 static DEVICE_ATTR_RO(cmo_allocated);
1004 static DEVICE_ATTR_RW(cmo_desired);
1005 static DEVICE_ATTR_RW(cmo_allocs_failed);
1006 
1007 static struct attribute *vio_cmo_dev_attrs[] = {
1008         &dev_attr_name.attr,
1009         &dev_attr_devspec.attr,
1010         &dev_attr_modalias.attr,
1011         &dev_attr_cmo_entitled.attr,
1012         &dev_attr_cmo_allocated.attr,
1013         &dev_attr_cmo_desired.attr,
1014         &dev_attr_cmo_allocs_failed.attr,
1015         NULL,
1016 };
1017 ATTRIBUTE_GROUPS(vio_cmo_dev);
1018 
1019 /* sysfs bus functions and data structures for CMO */
1020 
1021 #define viobus_cmo_rd_attr(name)                                        \
1022 static ssize_t cmo_bus_##name##_show(struct bus_type *bt, char *buf)    \
1023 {                                                                       \
1024         return sprintf(buf, "%lu\n", vio_cmo.name);                     \
1025 }                                                                       \
1026 static struct bus_attribute bus_attr_cmo_bus_##name =                   \
1027         __ATTR(cmo_##name, S_IRUGO, cmo_bus_##name##_show, NULL)
1028 
1029 #define viobus_cmo_pool_rd_attr(name, var)                              \
1030 static ssize_t                                                          \
1031 cmo_##name##_##var##_show(struct bus_type *bt, char *buf)               \
1032 {                                                                       \
1033         return sprintf(buf, "%lu\n", vio_cmo.name.var);                 \
1034 }                                                                       \
1035 static BUS_ATTR_RO(cmo_##name##_##var)
1036 
1037 viobus_cmo_rd_attr(entitled);
1038 viobus_cmo_rd_attr(spare);
1039 viobus_cmo_rd_attr(min);
1040 viobus_cmo_rd_attr(desired);
1041 viobus_cmo_rd_attr(curr);
1042 viobus_cmo_pool_rd_attr(reserve, size);
1043 viobus_cmo_pool_rd_attr(excess, size);
1044 viobus_cmo_pool_rd_attr(excess, free);
1045 
1046 static ssize_t cmo_high_show(struct bus_type *bt, char *buf)
1047 {
1048         return sprintf(buf, "%lu\n", vio_cmo.high);
1049 }
1050 
1051 static ssize_t cmo_high_store(struct bus_type *bt, const char *buf,
1052                               size_t count)
1053 {
1054         unsigned long flags;
1055 
1056         spin_lock_irqsave(&vio_cmo.lock, flags);
1057         vio_cmo.high = vio_cmo.curr;
1058         spin_unlock_irqrestore(&vio_cmo.lock, flags);
1059 
1060         return count;
1061 }
1062 static BUS_ATTR_RW(cmo_high);
1063 
1064 static struct attribute *vio_bus_attrs[] = {
1065         &bus_attr_cmo_bus_entitled.attr,
1066         &bus_attr_cmo_bus_spare.attr,
1067         &bus_attr_cmo_bus_min.attr,
1068         &bus_attr_cmo_bus_desired.attr,
1069         &bus_attr_cmo_bus_curr.attr,
1070         &bus_attr_cmo_high.attr,
1071         &bus_attr_cmo_reserve_size.attr,
1072         &bus_attr_cmo_excess_size.attr,
1073         &bus_attr_cmo_excess_free.attr,
1074         NULL,
1075 };
1076 ATTRIBUTE_GROUPS(vio_bus);
1077 
1078 static void vio_cmo_sysfs_init(void)
1079 {
1080         vio_bus_type.dev_groups = vio_cmo_dev_groups;
1081         vio_bus_type.bus_groups = vio_bus_groups;
1082 }
1083 #else /* CONFIG_PPC_SMLPAR */
1084 int vio_cmo_entitlement_update(size_t new_entitlement) { return 0; }
1085 void vio_cmo_set_dev_desired(struct vio_dev *viodev, size_t desired) {}
1086 static int vio_cmo_bus_probe(struct vio_dev *viodev) { return 0; }
1087 static void vio_cmo_bus_remove(struct vio_dev *viodev) {}
1088 static void vio_cmo_set_dma_ops(struct vio_dev *viodev) {}
1089 static void vio_cmo_bus_init(void) {}
1090 static void vio_cmo_sysfs_init(void) { }
1091 #endif /* CONFIG_PPC_SMLPAR */
1092 EXPORT_SYMBOL(vio_cmo_entitlement_update);
1093 EXPORT_SYMBOL(vio_cmo_set_dev_desired);
1094 
1095 
1096 /*
1097  * Platform Facilities Option (PFO) support
1098  */
1099 
1100 /**
1101  * vio_h_cop_sync - Perform a synchronous PFO co-processor operation
1102  *
1103  * @vdev - Pointer to a struct vio_dev for device
1104  * @op - Pointer to a struct vio_pfo_op for the operation parameters
1105  *
1106  * Calls the hypervisor to synchronously perform the PFO operation
1107  * described in @op.  In the case of a busy response from the hypervisor,
1108  * the operation will be re-submitted indefinitely unless a non-zero timeout
1109  * is specified or an error occurs. The timeout places a limit on when to
1110  * stop re-submitting a operation, the total time can be exceeded if an
1111  * operation is in progress.
1112  *
1113  * If op->hcall_ret is not NULL, this will be set to the return from the
1114  * last h_cop_op call or it will be 0 if an error not involving the h_call
1115  * was encountered.
1116  *
1117  * Returns:
1118  *      0 on success,
1119  *      -EINVAL if the h_call fails due to an invalid parameter,
1120  *      -E2BIG if the h_call can not be performed synchronously,
1121  *      -EBUSY if a timeout is specified and has elapsed,
1122  *      -EACCES if the memory area for data/status has been rescinded, or
1123  *      -EPERM if a hardware fault has been indicated
1124  */
1125 int vio_h_cop_sync(struct vio_dev *vdev, struct vio_pfo_op *op)
1126 {
1127         struct device *dev = &vdev->dev;
1128         unsigned long deadline = 0;
1129         long hret = 0;
1130         int ret = 0;
1131 
1132         if (op->timeout)
1133                 deadline = jiffies + msecs_to_jiffies(op->timeout);
1134 
1135         while (true) {
1136                 hret = plpar_hcall_norets(H_COP, op->flags,
1137                                 vdev->resource_id,
1138                                 op->in, op->inlen, op->out,
1139                                 op->outlen, op->csbcpb);
1140 
1141                 if (hret == H_SUCCESS ||
1142                     (hret != H_NOT_ENOUGH_RESOURCES &&
1143                      hret != H_BUSY && hret != H_RESOURCE) ||
1144                     (op->timeout && time_after(deadline, jiffies)))
1145                         break;
1146 
1147                 dev_dbg(dev, "%s: hcall ret(%ld), retrying.\n", __func__, hret);
1148         }
1149 
1150         switch (hret) {
1151         case H_SUCCESS:
1152                 ret = 0;
1153                 break;
1154         case H_OP_MODE:
1155         case H_TOO_BIG:
1156                 ret = -E2BIG;
1157                 break;
1158         case H_RESCINDED:
1159                 ret = -EACCES;
1160                 break;
1161         case H_HARDWARE:
1162                 ret = -EPERM;
1163                 break;
1164         case H_NOT_ENOUGH_RESOURCES:
1165         case H_RESOURCE:
1166         case H_BUSY:
1167                 ret = -EBUSY;
1168                 break;
1169         default:
1170                 ret = -EINVAL;
1171                 break;
1172         }
1173 
1174         if (ret)
1175                 dev_dbg(dev, "%s: Sync h_cop_op failure (ret:%d) (hret:%ld)\n",
1176                                 __func__, ret, hret);
1177 
1178         op->hcall_err = hret;
1179         return ret;
1180 }
1181 EXPORT_SYMBOL(vio_h_cop_sync);
1182 
1183 static struct iommu_table *vio_build_iommu_table(struct vio_dev *dev)
1184 {
1185         const __be32 *dma_window;
1186         struct iommu_table *tbl;
1187         unsigned long offset, size;
1188 
1189         dma_window = of_get_property(dev->dev.of_node,
1190                                   "ibm,my-dma-window", NULL);
1191         if (!dma_window)
1192                 return NULL;
1193 
1194         tbl = kzalloc(sizeof(*tbl), GFP_KERNEL);
1195         if (tbl == NULL)
1196                 return NULL;
1197 
1198         of_parse_dma_window(dev->dev.of_node, dma_window,
1199                             &tbl->it_index, &offset, &size);
1200 
1201         /* TCE table size - measured in tce entries */
1202         tbl->it_page_shift = IOMMU_PAGE_SHIFT_4K;
1203         tbl->it_size = size >> tbl->it_page_shift;
1204         /* offset for VIO should always be 0 */
1205         tbl->it_offset = offset >> tbl->it_page_shift;
1206         tbl->it_busno = 0;
1207         tbl->it_type = TCE_VB;
1208         tbl->it_blocksize = 16;
1209 
1210         if (firmware_has_feature(FW_FEATURE_LPAR))
1211                 tbl->it_ops = &iommu_table_lpar_multi_ops;
1212         else
1213                 tbl->it_ops = &iommu_table_pseries_ops;
1214 
1215         return iommu_init_table(tbl, -1);
1216 }
1217 
1218 /**
1219  * vio_match_device: - Tell if a VIO device has a matching
1220  *                      VIO device id structure.
1221  * @ids:        array of VIO device id structures to search in
1222  * @dev:        the VIO device structure to match against
1223  *
1224  * Used by a driver to check whether a VIO device present in the
1225  * system is in its list of supported devices. Returns the matching
1226  * vio_device_id structure or NULL if there is no match.
1227  */
1228 static const struct vio_device_id *vio_match_device(
1229                 const struct vio_device_id *ids, const struct vio_dev *dev)
1230 {
1231         while (ids->type[0] != '\0') {
1232                 if ((strncmp(dev->type, ids->type, strlen(ids->type)) == 0) &&
1233                     of_device_is_compatible(dev->dev.of_node,
1234                                          ids->compat))
1235                         return ids;
1236                 ids++;
1237         }
1238         return NULL;
1239 }
1240 
1241 /*
1242  * Convert from struct device to struct vio_dev and pass to driver.
1243  * dev->driver has already been set by generic code because vio_bus_match
1244  * succeeded.
1245  */
1246 static int vio_bus_probe(struct device *dev)
1247 {
1248         struct vio_dev *viodev = to_vio_dev(dev);
1249         struct vio_driver *viodrv = to_vio_driver(dev->driver);
1250         const struct vio_device_id *id;
1251         int error = -ENODEV;
1252 
1253         if (!viodrv->probe)
1254                 return error;
1255 
1256         id = vio_match_device(viodrv->id_table, viodev);
1257         if (id) {
1258                 memset(&viodev->cmo, 0, sizeof(viodev->cmo));
1259                 if (firmware_has_feature(FW_FEATURE_CMO)) {
1260                         error = vio_cmo_bus_probe(viodev);
1261                         if (error)
1262                                 return error;
1263                 }
1264                 error = viodrv->probe(viodev, id);
1265                 if (error && firmware_has_feature(FW_FEATURE_CMO))
1266                         vio_cmo_bus_remove(viodev);
1267         }
1268 
1269         return error;
1270 }
1271 
1272 /* convert from struct device to struct vio_dev and pass to driver. */
1273 static int vio_bus_remove(struct device *dev)
1274 {
1275         struct vio_dev *viodev = to_vio_dev(dev);
1276         struct vio_driver *viodrv = to_vio_driver(dev->driver);
1277         struct device *devptr;
1278         int ret = 1;
1279 
1280         /*
1281          * Hold a reference to the device after the remove function is called
1282          * to allow for CMO accounting cleanup for the device.
1283          */
1284         devptr = get_device(dev);
1285 
1286         if (viodrv->remove)
1287                 ret = viodrv->remove(viodev);
1288 
1289         if (!ret && firmware_has_feature(FW_FEATURE_CMO))
1290                 vio_cmo_bus_remove(viodev);
1291 
1292         put_device(devptr);
1293         return ret;
1294 }
1295 
1296 /**
1297  * vio_register_driver: - Register a new vio driver
1298  * @viodrv:     The vio_driver structure to be registered.
1299  */
1300 int __vio_register_driver(struct vio_driver *viodrv, struct module *owner,
1301                           const char *mod_name)
1302 {
1303         pr_debug("%s: driver %s registering\n", __func__, viodrv->name);
1304 
1305         /* fill in 'struct driver' fields */
1306         viodrv->driver.name = viodrv->name;
1307         viodrv->driver.pm = viodrv->pm;
1308         viodrv->driver.bus = &vio_bus_type;
1309         viodrv->driver.owner = owner;
1310         viodrv->driver.mod_name = mod_name;
1311 
1312         return driver_register(&viodrv->driver);
1313 }
1314 EXPORT_SYMBOL(__vio_register_driver);
1315 
1316 /**
1317  * vio_unregister_driver - Remove registration of vio driver.
1318  * @viodrv:     The vio_driver struct to be removed form registration
1319  */
1320 void vio_unregister_driver(struct vio_driver *viodrv)
1321 {
1322         driver_unregister(&viodrv->driver);
1323 }
1324 EXPORT_SYMBOL(vio_unregister_driver);
1325 
1326 /* vio_dev refcount hit 0 */
1327 static void vio_dev_release(struct device *dev)
1328 {
1329         struct iommu_table *tbl = get_iommu_table_base(dev);
1330 
1331         if (tbl)
1332                 iommu_tce_table_put(tbl);
1333         of_node_put(dev->of_node);
1334         kfree(to_vio_dev(dev));
1335 }
1336 
1337 /**
1338  * vio_register_device_node: - Register a new vio device.
1339  * @of_node:    The OF node for this device.
1340  *
1341  * Creates and initializes a vio_dev structure from the data in
1342  * of_node and adds it to the list of virtual devices.
1343  * Returns a pointer to the created vio_dev or NULL if node has
1344  * NULL device_type or compatible fields.
1345  */
1346 struct vio_dev *vio_register_device_node(struct device_node *of_node)
1347 {
1348         struct vio_dev *viodev;
1349         struct device_node *parent_node;
1350         const __be32 *prop;
1351         enum vio_dev_family family;
1352 
1353         /*
1354          * Determine if this node is a under the /vdevice node or under the
1355          * /ibm,platform-facilities node.  This decides the device's family.
1356          */
1357         parent_node = of_get_parent(of_node);
1358         if (parent_node) {
1359                 if (!strcmp(parent_node->type, "ibm,platform-facilities"))
1360                         family = PFO;
1361                 else if (!strcmp(parent_node->type, "vdevice"))
1362                         family = VDEVICE;
1363                 else {
1364                         pr_warn("%s: parent(%pOF) of %pOFn not recognized.\n",
1365                                         __func__,
1366                                         parent_node,
1367                                         of_node);
1368                         of_node_put(parent_node);
1369                         return NULL;
1370                 }
1371                 of_node_put(parent_node);
1372         } else {
1373                 pr_warn("%s: could not determine the parent of node %pOFn.\n",
1374                                 __func__, of_node);
1375                 return NULL;
1376         }
1377 
1378         if (family == PFO) {
1379                 if (of_get_property(of_node, "interrupt-controller", NULL)) {
1380                         pr_debug("%s: Skipping the interrupt controller %pOFn.\n",
1381                                         __func__, of_node);
1382                         return NULL;
1383                 }
1384         }
1385 
1386         /* allocate a vio_dev for this node */
1387         viodev = kzalloc(sizeof(struct vio_dev), GFP_KERNEL);
1388         if (viodev == NULL) {
1389                 pr_warn("%s: allocation failure for VIO device.\n", __func__);
1390                 return NULL;
1391         }
1392 
1393         /* we need the 'device_type' property, in order to match with drivers */
1394         viodev->family = family;
1395         if (viodev->family == VDEVICE) {
1396                 unsigned int unit_address;
1397 
1398                 if (of_node->type != NULL)
1399                         viodev->type = of_node->type;
1400                 else {
1401                         pr_warn("%s: node %pOFn is missing the 'device_type' "
1402                                         "property.\n", __func__, of_node);
1403                         goto out;
1404                 }
1405 
1406                 prop = of_get_property(of_node, "reg", NULL);
1407                 if (prop == NULL) {
1408                         pr_warn("%s: node %pOFn missing 'reg'\n",
1409                                         __func__, of_node);
1410                         goto out;
1411                 }
1412                 unit_address = of_read_number(prop, 1);
1413                 dev_set_name(&viodev->dev, "%x", unit_address);
1414                 viodev->irq = irq_of_parse_and_map(of_node, 0);
1415                 viodev->unit_address = unit_address;
1416         } else {
1417                 /* PFO devices need their resource_id for submitting COP_OPs
1418                  * This is an optional field for devices, but is required when
1419                  * performing synchronous ops */
1420                 prop = of_get_property(of_node, "ibm,resource-id", NULL);
1421                 if (prop != NULL)
1422                         viodev->resource_id = of_read_number(prop, 1);
1423 
1424                 dev_set_name(&viodev->dev, "%pOFn", of_node);
1425                 viodev->type = dev_name(&viodev->dev);
1426                 viodev->irq = 0;
1427         }
1428 
1429         viodev->name = of_node->name;
1430         viodev->dev.of_node = of_node_get(of_node);
1431 
1432         set_dev_node(&viodev->dev, of_node_to_nid(of_node));
1433 
1434         /* init generic 'struct device' fields: */
1435         viodev->dev.parent = &vio_bus_device.dev;
1436         viodev->dev.bus = &vio_bus_type;
1437         viodev->dev.release = vio_dev_release;
1438 
1439         if (of_get_property(viodev->dev.of_node, "ibm,my-dma-window", NULL)) {
1440                 if (firmware_has_feature(FW_FEATURE_CMO))
1441                         vio_cmo_set_dma_ops(viodev);
1442                 else
1443                         set_dma_ops(&viodev->dev, &dma_iommu_ops);
1444 
1445                 set_iommu_table_base(&viodev->dev,
1446                                      vio_build_iommu_table(viodev));
1447 
1448                 /* needed to ensure proper operation of coherent allocations
1449                  * later, in case driver doesn't set it explicitly */
1450                 viodev->dev.coherent_dma_mask = DMA_BIT_MASK(64);
1451                 viodev->dev.dma_mask = &viodev->dev.coherent_dma_mask;
1452         }
1453 
1454         /* register with generic device framework */
1455         if (device_register(&viodev->dev)) {
1456                 printk(KERN_ERR "%s: failed to register device %s\n",
1457                                 __func__, dev_name(&viodev->dev));
1458                 put_device(&viodev->dev);
1459                 return NULL;
1460         }
1461 
1462         return viodev;
1463 
1464 out:    /* Use this exit point for any return prior to device_register */
1465         kfree(viodev);
1466 
1467         return NULL;
1468 }
1469 EXPORT_SYMBOL(vio_register_device_node);
1470 
1471 /*
1472  * vio_bus_scan_for_devices - Scan OF and register each child device
1473  * @root_name - OF node name for the root of the subtree to search.
1474  *              This must be non-NULL
1475  *
1476  * Starting from the root node provide, register the device node for
1477  * each child beneath the root.
1478  */
1479 static void vio_bus_scan_register_devices(char *root_name)
1480 {
1481         struct device_node *node_root, *node_child;
1482 
1483         if (!root_name)
1484                 return;
1485 
1486         node_root = of_find_node_by_name(NULL, root_name);
1487         if (node_root) {
1488 
1489                 /*
1490                  * Create struct vio_devices for each virtual device in
1491                  * the device tree. Drivers will associate with them later.
1492                  */
1493                 node_child = of_get_next_child(node_root, NULL);
1494                 while (node_child) {
1495                         vio_register_device_node(node_child);
1496                         node_child = of_get_next_child(node_root, node_child);
1497                 }
1498                 of_node_put(node_root);
1499         }
1500 }
1501 
1502 /**
1503  * vio_bus_init: - Initialize the virtual IO bus
1504  */
1505 static int __init vio_bus_init(void)
1506 {
1507         int err;
1508 
1509         if (firmware_has_feature(FW_FEATURE_CMO))
1510                 vio_cmo_sysfs_init();
1511 
1512         err = bus_register(&vio_bus_type);
1513         if (err) {
1514                 printk(KERN_ERR "failed to register VIO bus\n");
1515                 return err;
1516         }
1517 
1518         /*
1519          * The fake parent of all vio devices, just to give us
1520          * a nice directory
1521          */
1522         err = device_register(&vio_bus_device.dev);
1523         if (err) {
1524                 printk(KERN_WARNING "%s: device_register returned %i\n",
1525                                 __func__, err);
1526                 return err;
1527         }
1528 
1529         if (firmware_has_feature(FW_FEATURE_CMO))
1530                 vio_cmo_bus_init();
1531 
1532         return 0;
1533 }
1534 postcore_initcall(vio_bus_init);
1535 
1536 static int __init vio_device_init(void)
1537 {
1538         vio_bus_scan_register_devices("vdevice");
1539         vio_bus_scan_register_devices("ibm,platform-facilities");
1540 
1541         return 0;
1542 }
1543 device_initcall(vio_device_init);
1544 
1545 static ssize_t name_show(struct device *dev,
1546                 struct device_attribute *attr, char *buf)
1547 {
1548         return sprintf(buf, "%s\n", to_vio_dev(dev)->name);
1549 }
1550 static DEVICE_ATTR_RO(name);
1551 
1552 static ssize_t devspec_show(struct device *dev,
1553                 struct device_attribute *attr, char *buf)
1554 {
1555         struct device_node *of_node = dev->of_node;
1556 
1557         return sprintf(buf, "%pOF\n", of_node);
1558 }
1559 static DEVICE_ATTR_RO(devspec);
1560 
1561 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
1562                              char *buf)
1563 {
1564         const struct vio_dev *vio_dev = to_vio_dev(dev);
1565         struct device_node *dn;
1566         const char *cp;
1567 
1568         dn = dev->of_node;
1569         if (!dn) {
1570                 strcpy(buf, "\n");
1571                 return strlen(buf);
1572         }
1573         cp = of_get_property(dn, "compatible", NULL);
1574         if (!cp) {
1575                 strcpy(buf, "\n");
1576                 return strlen(buf);
1577         }
1578 
1579         return sprintf(buf, "vio:T%sS%s\n", vio_dev->type, cp);
1580 }
1581 static DEVICE_ATTR_RO(modalias);
1582 
1583 static struct attribute *vio_dev_attrs[] = {
1584         &dev_attr_name.attr,
1585         &dev_attr_devspec.attr,
1586         &dev_attr_modalias.attr,
1587         NULL,
1588 };
1589 ATTRIBUTE_GROUPS(vio_dev);
1590 
1591 void vio_unregister_device(struct vio_dev *viodev)
1592 {
1593         device_unregister(&viodev->dev);
1594         if (viodev->family == VDEVICE)
1595                 irq_dispose_mapping(viodev->irq);
1596 }
1597 EXPORT_SYMBOL(vio_unregister_device);
1598 
1599 static int vio_bus_match(struct device *dev, struct device_driver *drv)
1600 {
1601         const struct vio_dev *vio_dev = to_vio_dev(dev);
1602         struct vio_driver *vio_drv = to_vio_driver(drv);
1603         const struct vio_device_id *ids = vio_drv->id_table;
1604 
1605         return (ids != NULL) && (vio_match_device(ids, vio_dev) != NULL);
1606 }
1607 
1608 static int vio_hotplug(struct device *dev, struct kobj_uevent_env *env)
1609 {
1610         const struct vio_dev *vio_dev = to_vio_dev(dev);
1611         struct device_node *dn;
1612         const char *cp;
1613 
1614         dn = dev->of_node;
1615         if (!dn)
1616                 return -ENODEV;
1617         cp = of_get_property(dn, "compatible", NULL);
1618         if (!cp)
1619                 return -ENODEV;
1620 
1621         add_uevent_var(env, "MODALIAS=vio:T%sS%s", vio_dev->type, cp);
1622         return 0;
1623 }
1624 
1625 struct bus_type vio_bus_type = {
1626         .name = "vio",
1627         .dev_groups = vio_dev_groups,
1628         .uevent = vio_hotplug,
1629         .match = vio_bus_match,
1630         .probe = vio_bus_probe,
1631         .remove = vio_bus_remove,
1632 };
1633 
1634 /**
1635  * vio_get_attribute: - get attribute for virtual device
1636  * @vdev:       The vio device to get property.
1637  * @which:      The property/attribute to be extracted.
1638  * @length:     Pointer to length of returned data size (unused if NULL).
1639  *
1640  * Calls prom.c's of_get_property() to return the value of the
1641  * attribute specified by @which
1642 */
1643 const void *vio_get_attribute(struct vio_dev *vdev, char *which, int *length)
1644 {
1645         return of_get_property(vdev->dev.of_node, which, length);
1646 }
1647 EXPORT_SYMBOL(vio_get_attribute);
1648 
1649 #ifdef CONFIG_PPC_PSERIES
1650 /* vio_find_name() - internal because only vio.c knows how we formatted the
1651  * kobject name
1652  */
1653 static struct vio_dev *vio_find_name(const char *name)
1654 {
1655         struct device *found;
1656 
1657         found = bus_find_device_by_name(&vio_bus_type, NULL, name);
1658         if (!found)
1659                 return NULL;
1660 
1661         return to_vio_dev(found);
1662 }
1663 
1664 /**
1665  * vio_find_node - find an already-registered vio_dev
1666  * @vnode: device_node of the virtual device we're looking for
1667  *
1668  * Takes a reference to the embedded struct device which needs to be dropped
1669  * after use.
1670  */
1671 struct vio_dev *vio_find_node(struct device_node *vnode)
1672 {
1673         char kobj_name[20];
1674         struct device_node *vnode_parent;
1675         const char *dev_type;
1676 
1677         vnode_parent = of_get_parent(vnode);
1678         if (!vnode_parent)
1679                 return NULL;
1680 
1681         dev_type = of_get_property(vnode_parent, "device_type", NULL);
1682         of_node_put(vnode_parent);
1683         if (!dev_type)
1684                 return NULL;
1685 
1686         /* construct the kobject name from the device node */
1687         if (!strcmp(dev_type, "vdevice")) {
1688                 const __be32 *prop;
1689                 
1690                 prop = of_get_property(vnode, "reg", NULL);
1691                 if (!prop)
1692                         return NULL;
1693                 snprintf(kobj_name, sizeof(kobj_name), "%x",
1694                          (uint32_t)of_read_number(prop, 1));
1695         } else if (!strcmp(dev_type, "ibm,platform-facilities"))
1696                 snprintf(kobj_name, sizeof(kobj_name), "%pOFn", vnode);
1697         else
1698                 return NULL;
1699 
1700         return vio_find_name(kobj_name);
1701 }
1702 EXPORT_SYMBOL(vio_find_node);
1703 
1704 int vio_enable_interrupts(struct vio_dev *dev)
1705 {
1706         int rc = h_vio_signal(dev->unit_address, VIO_IRQ_ENABLE);
1707         if (rc != H_SUCCESS)
1708                 printk(KERN_ERR "vio: Error 0x%x enabling interrupts\n", rc);
1709         return rc;
1710 }
1711 EXPORT_SYMBOL(vio_enable_interrupts);
1712 
1713 int vio_disable_interrupts(struct vio_dev *dev)
1714 {
1715         int rc = h_vio_signal(dev->unit_address, VIO_IRQ_DISABLE);
1716         if (rc != H_SUCCESS)
1717                 printk(KERN_ERR "vio: Error 0x%x disabling interrupts\n", rc);
1718         return rc;
1719 }
1720 EXPORT_SYMBOL(vio_disable_interrupts);
1721 #endif /* CONFIG_PPC_PSERIES */
1722 

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