Loading...
1/* via_dmablit.c -- PCI DMA BitBlt support for the VIA Unichrome/Pro
2 *
3 * Copyright (C) 2005 Thomas Hellstrom, All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sub license,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the
13 * next paragraph) shall be included in all copies or substantial portions
14 * of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
22 * USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 * Thomas Hellstrom.
26 * Partially based on code obtained from Digeo Inc.
27 */
28
29
30/*
31 * Unmaps the DMA mappings.
32 * FIXME: Is this a NoOp on x86? Also
33 * FIXME: What happens if this one is called and a pending blit has previously done
34 * the same DMA mappings?
35 */
36
37#include <drm/drmP.h>
38#include <drm/via_drm.h>
39#include "via_drv.h"
40#include "via_dmablit.h"
41
42#include <linux/pagemap.h>
43#include <linux/slab.h>
44
45#define VIA_PGDN(x) (((unsigned long)(x)) & PAGE_MASK)
46#define VIA_PGOFF(x) (((unsigned long)(x)) & ~PAGE_MASK)
47#define VIA_PFN(x) ((unsigned long)(x) >> PAGE_SHIFT)
48
49typedef struct _drm_via_descriptor {
50 uint32_t mem_addr;
51 uint32_t dev_addr;
52 uint32_t size;
53 uint32_t next;
54} drm_via_descriptor_t;
55
56
57/*
58 * Unmap a DMA mapping.
59 */
60
61
62
63static void
64via_unmap_blit_from_device(struct pci_dev *pdev, drm_via_sg_info_t *vsg)
65{
66 int num_desc = vsg->num_desc;
67 unsigned cur_descriptor_page = num_desc / vsg->descriptors_per_page;
68 unsigned descriptor_this_page = num_desc % vsg->descriptors_per_page;
69 drm_via_descriptor_t *desc_ptr = vsg->desc_pages[cur_descriptor_page] +
70 descriptor_this_page;
71 dma_addr_t next = vsg->chain_start;
72
73 while (num_desc--) {
74 if (descriptor_this_page-- == 0) {
75 cur_descriptor_page--;
76 descriptor_this_page = vsg->descriptors_per_page - 1;
77 desc_ptr = vsg->desc_pages[cur_descriptor_page] +
78 descriptor_this_page;
79 }
80 dma_unmap_single(&pdev->dev, next, sizeof(*desc_ptr), DMA_TO_DEVICE);
81 dma_unmap_page(&pdev->dev, desc_ptr->mem_addr, desc_ptr->size, vsg->direction);
82 next = (dma_addr_t) desc_ptr->next;
83 desc_ptr--;
84 }
85}
86
87/*
88 * If mode = 0, count how many descriptors are needed.
89 * If mode = 1, Map the DMA pages for the device, put together and map also the descriptors.
90 * Descriptors are run in reverse order by the hardware because we are not allowed to update the
91 * 'next' field without syncing calls when the descriptor is already mapped.
92 */
93
94static void
95via_map_blit_for_device(struct pci_dev *pdev,
96 const drm_via_dmablit_t *xfer,
97 drm_via_sg_info_t *vsg,
98 int mode)
99{
100 unsigned cur_descriptor_page = 0;
101 unsigned num_descriptors_this_page = 0;
102 unsigned char *mem_addr = xfer->mem_addr;
103 unsigned char *cur_mem;
104 unsigned char *first_addr = (unsigned char *)VIA_PGDN(mem_addr);
105 uint32_t fb_addr = xfer->fb_addr;
106 uint32_t cur_fb;
107 unsigned long line_len;
108 unsigned remaining_len;
109 int num_desc = 0;
110 int cur_line;
111 dma_addr_t next = 0 | VIA_DMA_DPR_EC;
112 drm_via_descriptor_t *desc_ptr = NULL;
113
114 if (mode == 1)
115 desc_ptr = vsg->desc_pages[cur_descriptor_page];
116
117 for (cur_line = 0; cur_line < xfer->num_lines; ++cur_line) {
118
119 line_len = xfer->line_length;
120 cur_fb = fb_addr;
121 cur_mem = mem_addr;
122
123 while (line_len > 0) {
124
125 remaining_len = min(PAGE_SIZE-VIA_PGOFF(cur_mem), line_len);
126 line_len -= remaining_len;
127
128 if (mode == 1) {
129 desc_ptr->mem_addr =
130 dma_map_page(&pdev->dev,
131 vsg->pages[VIA_PFN(cur_mem) -
132 VIA_PFN(first_addr)],
133 VIA_PGOFF(cur_mem), remaining_len,
134 vsg->direction);
135 desc_ptr->dev_addr = cur_fb;
136
137 desc_ptr->size = remaining_len;
138 desc_ptr->next = (uint32_t) next;
139 next = dma_map_single(&pdev->dev, desc_ptr, sizeof(*desc_ptr),
140 DMA_TO_DEVICE);
141 desc_ptr++;
142 if (++num_descriptors_this_page >= vsg->descriptors_per_page) {
143 num_descriptors_this_page = 0;
144 desc_ptr = vsg->desc_pages[++cur_descriptor_page];
145 }
146 }
147
148 num_desc++;
149 cur_mem += remaining_len;
150 cur_fb += remaining_len;
151 }
152
153 mem_addr += xfer->mem_stride;
154 fb_addr += xfer->fb_stride;
155 }
156
157 if (mode == 1) {
158 vsg->chain_start = next;
159 vsg->state = dr_via_device_mapped;
160 }
161 vsg->num_desc = num_desc;
162}
163
164/*
165 * Function that frees up all resources for a blit. It is usable even if the
166 * blit info has only been partially built as long as the status enum is consistent
167 * with the actual status of the used resources.
168 */
169
170
171static void
172via_free_sg_info(struct pci_dev *pdev, drm_via_sg_info_t *vsg)
173{
174 struct page *page;
175 int i;
176
177 switch (vsg->state) {
178 case dr_via_device_mapped:
179 via_unmap_blit_from_device(pdev, vsg);
180 case dr_via_desc_pages_alloc:
181 for (i = 0; i < vsg->num_desc_pages; ++i) {
182 if (vsg->desc_pages[i] != NULL)
183 free_page((unsigned long)vsg->desc_pages[i]);
184 }
185 kfree(vsg->desc_pages);
186 case dr_via_pages_locked:
187 for (i = 0; i < vsg->num_pages; ++i) {
188 if (NULL != (page = vsg->pages[i])) {
189 if (!PageReserved(page) && (DMA_FROM_DEVICE == vsg->direction))
190 SetPageDirty(page);
191 put_page(page);
192 }
193 }
194 case dr_via_pages_alloc:
195 vfree(vsg->pages);
196 default:
197 vsg->state = dr_via_sg_init;
198 }
199 vfree(vsg->bounce_buffer);
200 vsg->bounce_buffer = NULL;
201 vsg->free_on_sequence = 0;
202}
203
204/*
205 * Fire a blit engine.
206 */
207
208static void
209via_fire_dmablit(struct drm_device *dev, drm_via_sg_info_t *vsg, int engine)
210{
211 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
212
213 VIA_WRITE(VIA_PCI_DMA_MAR0 + engine*0x10, 0);
214 VIA_WRITE(VIA_PCI_DMA_DAR0 + engine*0x10, 0);
215 VIA_WRITE(VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_DD | VIA_DMA_CSR_TD |
216 VIA_DMA_CSR_DE);
217 VIA_WRITE(VIA_PCI_DMA_MR0 + engine*0x04, VIA_DMA_MR_CM | VIA_DMA_MR_TDIE);
218 VIA_WRITE(VIA_PCI_DMA_BCR0 + engine*0x10, 0);
219 VIA_WRITE(VIA_PCI_DMA_DPR0 + engine*0x10, vsg->chain_start);
220 wmb();
221 VIA_WRITE(VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_DE | VIA_DMA_CSR_TS);
222 VIA_READ(VIA_PCI_DMA_CSR0 + engine*0x04);
223}
224
225/*
226 * Obtain a page pointer array and lock all pages into system memory. A segmentation violation will
227 * occur here if the calling user does not have access to the submitted address.
228 */
229
230static int
231via_lock_all_dma_pages(drm_via_sg_info_t *vsg, drm_via_dmablit_t *xfer)
232{
233 int ret;
234 unsigned long first_pfn = VIA_PFN(xfer->mem_addr);
235 vsg->num_pages = VIA_PFN(xfer->mem_addr + (xfer->num_lines * xfer->mem_stride - 1)) -
236 first_pfn + 1;
237
238 vsg->pages = vzalloc(sizeof(struct page *) * vsg->num_pages);
239 if (NULL == vsg->pages)
240 return -ENOMEM;
241 down_read(¤t->mm->mmap_sem);
242 ret = get_user_pages((unsigned long)xfer->mem_addr,
243 vsg->num_pages,
244 (vsg->direction == DMA_FROM_DEVICE),
245 0, vsg->pages, NULL);
246
247 up_read(¤t->mm->mmap_sem);
248 if (ret != vsg->num_pages) {
249 if (ret < 0)
250 return ret;
251 vsg->state = dr_via_pages_locked;
252 return -EINVAL;
253 }
254 vsg->state = dr_via_pages_locked;
255 DRM_DEBUG("DMA pages locked\n");
256 return 0;
257}
258
259/*
260 * Allocate DMA capable memory for the blit descriptor chain, and an array that keeps track of the
261 * pages we allocate. We don't want to use kmalloc for the descriptor chain because it may be
262 * quite large for some blits, and pages don't need to be contiguous.
263 */
264
265static int
266via_alloc_desc_pages(drm_via_sg_info_t *vsg)
267{
268 int i;
269
270 vsg->descriptors_per_page = PAGE_SIZE / sizeof(drm_via_descriptor_t);
271 vsg->num_desc_pages = (vsg->num_desc + vsg->descriptors_per_page - 1) /
272 vsg->descriptors_per_page;
273
274 if (NULL == (vsg->desc_pages = kcalloc(vsg->num_desc_pages, sizeof(void *), GFP_KERNEL)))
275 return -ENOMEM;
276
277 vsg->state = dr_via_desc_pages_alloc;
278 for (i = 0; i < vsg->num_desc_pages; ++i) {
279 if (NULL == (vsg->desc_pages[i] =
280 (drm_via_descriptor_t *) __get_free_page(GFP_KERNEL)))
281 return -ENOMEM;
282 }
283 DRM_DEBUG("Allocated %d pages for %d descriptors.\n", vsg->num_desc_pages,
284 vsg->num_desc);
285 return 0;
286}
287
288static void
289via_abort_dmablit(struct drm_device *dev, int engine)
290{
291 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
292
293 VIA_WRITE(VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_TA);
294}
295
296static void
297via_dmablit_engine_off(struct drm_device *dev, int engine)
298{
299 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
300
301 VIA_WRITE(VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_TD | VIA_DMA_CSR_DD);
302}
303
304
305
306/*
307 * The dmablit part of the IRQ handler. Trying to do only reasonably fast things here.
308 * The rest, like unmapping and freeing memory for done blits is done in a separate workqueue
309 * task. Basically the task of the interrupt handler is to submit a new blit to the engine, while
310 * the workqueue task takes care of processing associated with the old blit.
311 */
312
313void
314via_dmablit_handler(struct drm_device *dev, int engine, int from_irq)
315{
316 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
317 drm_via_blitq_t *blitq = dev_priv->blit_queues + engine;
318 int cur;
319 int done_transfer;
320 unsigned long irqsave = 0;
321 uint32_t status = 0;
322
323 DRM_DEBUG("DMA blit handler called. engine = %d, from_irq = %d, blitq = 0x%lx\n",
324 engine, from_irq, (unsigned long) blitq);
325
326 if (from_irq)
327 spin_lock(&blitq->blit_lock);
328 else
329 spin_lock_irqsave(&blitq->blit_lock, irqsave);
330
331 done_transfer = blitq->is_active &&
332 ((status = VIA_READ(VIA_PCI_DMA_CSR0 + engine*0x04)) & VIA_DMA_CSR_TD);
333 done_transfer = done_transfer || (blitq->aborting && !(status & VIA_DMA_CSR_DE));
334
335 cur = blitq->cur;
336 if (done_transfer) {
337
338 blitq->blits[cur]->aborted = blitq->aborting;
339 blitq->done_blit_handle++;
340 wake_up(blitq->blit_queue + cur);
341
342 cur++;
343 if (cur >= VIA_NUM_BLIT_SLOTS)
344 cur = 0;
345 blitq->cur = cur;
346
347 /*
348 * Clear transfer done flag.
349 */
350
351 VIA_WRITE(VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_TD);
352
353 blitq->is_active = 0;
354 blitq->aborting = 0;
355 schedule_work(&blitq->wq);
356
357 } else if (blitq->is_active && time_after_eq(jiffies, blitq->end)) {
358
359 /*
360 * Abort transfer after one second.
361 */
362
363 via_abort_dmablit(dev, engine);
364 blitq->aborting = 1;
365 blitq->end = jiffies + HZ;
366 }
367
368 if (!blitq->is_active) {
369 if (blitq->num_outstanding) {
370 via_fire_dmablit(dev, blitq->blits[cur], engine);
371 blitq->is_active = 1;
372 blitq->cur = cur;
373 blitq->num_outstanding--;
374 blitq->end = jiffies + HZ;
375 if (!timer_pending(&blitq->poll_timer))
376 mod_timer(&blitq->poll_timer, jiffies + 1);
377 } else {
378 if (timer_pending(&blitq->poll_timer))
379 del_timer(&blitq->poll_timer);
380 via_dmablit_engine_off(dev, engine);
381 }
382 }
383
384 if (from_irq)
385 spin_unlock(&blitq->blit_lock);
386 else
387 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
388}
389
390
391
392/*
393 * Check whether this blit is still active, performing necessary locking.
394 */
395
396static int
397via_dmablit_active(drm_via_blitq_t *blitq, int engine, uint32_t handle, wait_queue_head_t **queue)
398{
399 unsigned long irqsave;
400 uint32_t slot;
401 int active;
402
403 spin_lock_irqsave(&blitq->blit_lock, irqsave);
404
405 /*
406 * Allow for handle wraparounds.
407 */
408
409 active = ((blitq->done_blit_handle - handle) > (1 << 23)) &&
410 ((blitq->cur_blit_handle - handle) <= (1 << 23));
411
412 if (queue && active) {
413 slot = handle - blitq->done_blit_handle + blitq->cur - 1;
414 if (slot >= VIA_NUM_BLIT_SLOTS)
415 slot -= VIA_NUM_BLIT_SLOTS;
416 *queue = blitq->blit_queue + slot;
417 }
418
419 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
420
421 return active;
422}
423
424/*
425 * Sync. Wait for at least three seconds for the blit to be performed.
426 */
427
428static int
429via_dmablit_sync(struct drm_device *dev, uint32_t handle, int engine)
430{
431
432 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
433 drm_via_blitq_t *blitq = dev_priv->blit_queues + engine;
434 wait_queue_head_t *queue;
435 int ret = 0;
436
437 if (via_dmablit_active(blitq, engine, handle, &queue)) {
438 DRM_WAIT_ON(ret, *queue, 3 * HZ,
439 !via_dmablit_active(blitq, engine, handle, NULL));
440 }
441 DRM_DEBUG("DMA blit sync handle 0x%x engine %d returned %d\n",
442 handle, engine, ret);
443
444 return ret;
445}
446
447
448/*
449 * A timer that regularly polls the blit engine in cases where we don't have interrupts:
450 * a) Broken hardware (typically those that don't have any video capture facility).
451 * b) Blit abort. The hardware doesn't send an interrupt when a blit is aborted.
452 * The timer and hardware IRQ's can and do work in parallel. If the hardware has
453 * irqs, it will shorten the latency somewhat.
454 */
455
456
457
458static void
459via_dmablit_timer(unsigned long data)
460{
461 drm_via_blitq_t *blitq = (drm_via_blitq_t *) data;
462 struct drm_device *dev = blitq->dev;
463 int engine = (int)
464 (blitq - ((drm_via_private_t *)dev->dev_private)->blit_queues);
465
466 DRM_DEBUG("Polling timer called for engine %d, jiffies %lu\n", engine,
467 (unsigned long) jiffies);
468
469 via_dmablit_handler(dev, engine, 0);
470
471 if (!timer_pending(&blitq->poll_timer)) {
472 mod_timer(&blitq->poll_timer, jiffies + 1);
473
474 /*
475 * Rerun handler to delete timer if engines are off, and
476 * to shorten abort latency. This is a little nasty.
477 */
478
479 via_dmablit_handler(dev, engine, 0);
480
481 }
482}
483
484
485
486
487/*
488 * Workqueue task that frees data and mappings associated with a blit.
489 * Also wakes up waiting processes. Each of these tasks handles one
490 * blit engine only and may not be called on each interrupt.
491 */
492
493
494static void
495via_dmablit_workqueue(struct work_struct *work)
496{
497 drm_via_blitq_t *blitq = container_of(work, drm_via_blitq_t, wq);
498 struct drm_device *dev = blitq->dev;
499 unsigned long irqsave;
500 drm_via_sg_info_t *cur_sg;
501 int cur_released;
502
503
504 DRM_DEBUG("Workqueue task called for blit engine %ld\n", (unsigned long)
505 (blitq - ((drm_via_private_t *)dev->dev_private)->blit_queues));
506
507 spin_lock_irqsave(&blitq->blit_lock, irqsave);
508
509 while (blitq->serviced != blitq->cur) {
510
511 cur_released = blitq->serviced++;
512
513 DRM_DEBUG("Releasing blit slot %d\n", cur_released);
514
515 if (blitq->serviced >= VIA_NUM_BLIT_SLOTS)
516 blitq->serviced = 0;
517
518 cur_sg = blitq->blits[cur_released];
519 blitq->num_free++;
520
521 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
522
523 wake_up(&blitq->busy_queue);
524
525 via_free_sg_info(dev->pdev, cur_sg);
526 kfree(cur_sg);
527
528 spin_lock_irqsave(&blitq->blit_lock, irqsave);
529 }
530
531 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
532}
533
534
535/*
536 * Init all blit engines. Currently we use two, but some hardware have 4.
537 */
538
539
540void
541via_init_dmablit(struct drm_device *dev)
542{
543 int i, j;
544 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
545 drm_via_blitq_t *blitq;
546
547 pci_set_master(dev->pdev);
548
549 for (i = 0; i < VIA_NUM_BLIT_ENGINES; ++i) {
550 blitq = dev_priv->blit_queues + i;
551 blitq->dev = dev;
552 blitq->cur_blit_handle = 0;
553 blitq->done_blit_handle = 0;
554 blitq->head = 0;
555 blitq->cur = 0;
556 blitq->serviced = 0;
557 blitq->num_free = VIA_NUM_BLIT_SLOTS - 1;
558 blitq->num_outstanding = 0;
559 blitq->is_active = 0;
560 blitq->aborting = 0;
561 spin_lock_init(&blitq->blit_lock);
562 for (j = 0; j < VIA_NUM_BLIT_SLOTS; ++j)
563 init_waitqueue_head(blitq->blit_queue + j);
564 init_waitqueue_head(&blitq->busy_queue);
565 INIT_WORK(&blitq->wq, via_dmablit_workqueue);
566 setup_timer(&blitq->poll_timer, via_dmablit_timer,
567 (unsigned long)blitq);
568 }
569}
570
571/*
572 * Build all info and do all mappings required for a blit.
573 */
574
575
576static int
577via_build_sg_info(struct drm_device *dev, drm_via_sg_info_t *vsg, drm_via_dmablit_t *xfer)
578{
579 int draw = xfer->to_fb;
580 int ret = 0;
581
582 vsg->direction = (draw) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
583 vsg->bounce_buffer = NULL;
584
585 vsg->state = dr_via_sg_init;
586
587 if (xfer->num_lines <= 0 || xfer->line_length <= 0) {
588 DRM_ERROR("Zero size bitblt.\n");
589 return -EINVAL;
590 }
591
592 /*
593 * Below check is a driver limitation, not a hardware one. We
594 * don't want to lock unused pages, and don't want to incoporate the
595 * extra logic of avoiding them. Make sure there are no.
596 * (Not a big limitation anyway.)
597 */
598
599 if ((xfer->mem_stride - xfer->line_length) > 2*PAGE_SIZE) {
600 DRM_ERROR("Too large system memory stride. Stride: %d, "
601 "Length: %d\n", xfer->mem_stride, xfer->line_length);
602 return -EINVAL;
603 }
604
605 if ((xfer->mem_stride == xfer->line_length) &&
606 (xfer->fb_stride == xfer->line_length)) {
607 xfer->mem_stride *= xfer->num_lines;
608 xfer->line_length = xfer->mem_stride;
609 xfer->fb_stride = xfer->mem_stride;
610 xfer->num_lines = 1;
611 }
612
613 /*
614 * Don't lock an arbitrary large number of pages, since that causes a
615 * DOS security hole.
616 */
617
618 if (xfer->num_lines > 2048 || (xfer->num_lines*xfer->mem_stride > (2048*2048*4))) {
619 DRM_ERROR("Too large PCI DMA bitblt.\n");
620 return -EINVAL;
621 }
622
623 /*
624 * we allow a negative fb stride to allow flipping of images in
625 * transfer.
626 */
627
628 if (xfer->mem_stride < xfer->line_length ||
629 abs(xfer->fb_stride) < xfer->line_length) {
630 DRM_ERROR("Invalid frame-buffer / memory stride.\n");
631 return -EINVAL;
632 }
633
634 /*
635 * A hardware bug seems to be worked around if system memory addresses start on
636 * 16 byte boundaries. This seems a bit restrictive however. VIA is contacted
637 * about this. Meanwhile, impose the following restrictions:
638 */
639
640#ifdef VIA_BUGFREE
641 if ((((unsigned long)xfer->mem_addr & 3) != ((unsigned long)xfer->fb_addr & 3)) ||
642 ((xfer->num_lines > 1) && ((xfer->mem_stride & 3) != (xfer->fb_stride & 3)))) {
643 DRM_ERROR("Invalid DRM bitblt alignment.\n");
644 return -EINVAL;
645 }
646#else
647 if ((((unsigned long)xfer->mem_addr & 15) ||
648 ((unsigned long)xfer->fb_addr & 3)) ||
649 ((xfer->num_lines > 1) &&
650 ((xfer->mem_stride & 15) || (xfer->fb_stride & 3)))) {
651 DRM_ERROR("Invalid DRM bitblt alignment.\n");
652 return -EINVAL;
653 }
654#endif
655
656 if (0 != (ret = via_lock_all_dma_pages(vsg, xfer))) {
657 DRM_ERROR("Could not lock DMA pages.\n");
658 via_free_sg_info(dev->pdev, vsg);
659 return ret;
660 }
661
662 via_map_blit_for_device(dev->pdev, xfer, vsg, 0);
663 if (0 != (ret = via_alloc_desc_pages(vsg))) {
664 DRM_ERROR("Could not allocate DMA descriptor pages.\n");
665 via_free_sg_info(dev->pdev, vsg);
666 return ret;
667 }
668 via_map_blit_for_device(dev->pdev, xfer, vsg, 1);
669
670 return 0;
671}
672
673
674/*
675 * Reserve one free slot in the blit queue. Will wait for one second for one
676 * to become available. Otherwise -EBUSY is returned.
677 */
678
679static int
680via_dmablit_grab_slot(drm_via_blitq_t *blitq, int engine)
681{
682 int ret = 0;
683 unsigned long irqsave;
684
685 DRM_DEBUG("Num free is %d\n", blitq->num_free);
686 spin_lock_irqsave(&blitq->blit_lock, irqsave);
687 while (blitq->num_free == 0) {
688 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
689
690 DRM_WAIT_ON(ret, blitq->busy_queue, HZ, blitq->num_free > 0);
691 if (ret)
692 return (-EINTR == ret) ? -EAGAIN : ret;
693
694 spin_lock_irqsave(&blitq->blit_lock, irqsave);
695 }
696
697 blitq->num_free--;
698 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
699
700 return 0;
701}
702
703/*
704 * Hand back a free slot if we changed our mind.
705 */
706
707static void
708via_dmablit_release_slot(drm_via_blitq_t *blitq)
709{
710 unsigned long irqsave;
711
712 spin_lock_irqsave(&blitq->blit_lock, irqsave);
713 blitq->num_free++;
714 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
715 wake_up(&blitq->busy_queue);
716}
717
718/*
719 * Grab a free slot. Build blit info and queue a blit.
720 */
721
722
723static int
724via_dmablit(struct drm_device *dev, drm_via_dmablit_t *xfer)
725{
726 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
727 drm_via_sg_info_t *vsg;
728 drm_via_blitq_t *blitq;
729 int ret;
730 int engine;
731 unsigned long irqsave;
732
733 if (dev_priv == NULL) {
734 DRM_ERROR("Called without initialization.\n");
735 return -EINVAL;
736 }
737
738 engine = (xfer->to_fb) ? 0 : 1;
739 blitq = dev_priv->blit_queues + engine;
740 if (0 != (ret = via_dmablit_grab_slot(blitq, engine)))
741 return ret;
742 if (NULL == (vsg = kmalloc(sizeof(*vsg), GFP_KERNEL))) {
743 via_dmablit_release_slot(blitq);
744 return -ENOMEM;
745 }
746 if (0 != (ret = via_build_sg_info(dev, vsg, xfer))) {
747 via_dmablit_release_slot(blitq);
748 kfree(vsg);
749 return ret;
750 }
751 spin_lock_irqsave(&blitq->blit_lock, irqsave);
752
753 blitq->blits[blitq->head++] = vsg;
754 if (blitq->head >= VIA_NUM_BLIT_SLOTS)
755 blitq->head = 0;
756 blitq->num_outstanding++;
757 xfer->sync.sync_handle = ++blitq->cur_blit_handle;
758
759 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
760 xfer->sync.engine = engine;
761
762 via_dmablit_handler(dev, engine, 0);
763
764 return 0;
765}
766
767/*
768 * Sync on a previously submitted blit. Note that the X server use signals extensively, and
769 * that there is a very big probability that this IOCTL will be interrupted by a signal. In that
770 * case it returns with -EAGAIN for the signal to be delivered.
771 * The caller should then reissue the IOCTL. This is similar to what is being done for drmGetLock().
772 */
773
774int
775via_dma_blit_sync(struct drm_device *dev, void *data, struct drm_file *file_priv)
776{
777 drm_via_blitsync_t *sync = data;
778 int err;
779
780 if (sync->engine >= VIA_NUM_BLIT_ENGINES)
781 return -EINVAL;
782
783 err = via_dmablit_sync(dev, sync->sync_handle, sync->engine);
784
785 if (-EINTR == err)
786 err = -EAGAIN;
787
788 return err;
789}
790
791
792/*
793 * Queue a blit and hand back a handle to be used for sync. This IOCTL may be interrupted by a signal
794 * while waiting for a free slot in the blit queue. In that case it returns with -EAGAIN and should
795 * be reissued. See the above IOCTL code.
796 */
797
798int
799via_dma_blit(struct drm_device *dev, void *data, struct drm_file *file_priv)
800{
801 drm_via_dmablit_t *xfer = data;
802 int err;
803
804 err = via_dmablit(dev, xfer);
805
806 return err;
807}
1/* via_dmablit.c -- PCI DMA BitBlt support for the VIA Unichrome/Pro
2 *
3 * Copyright (C) 2005 Thomas Hellstrom, All Rights Reserved.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sub license,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice (including the
13 * next paragraph) shall be included in all copies or substantial portions
14 * of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
20 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
21 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
22 * USE OR OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors:
25 * Thomas Hellstrom.
26 * Partially based on code obtained from Digeo Inc.
27 */
28
29
30/*
31 * Unmaps the DMA mappings.
32 * FIXME: Is this a NoOp on x86? Also
33 * FIXME: What happens if this one is called and a pending blit has previously done
34 * the same DMA mappings?
35 */
36
37#include <linux/pagemap.h>
38#include <linux/pci.h>
39#include <linux/slab.h>
40#include <linux/vmalloc.h>
41
42#include <drm/drm_device.h>
43#include <drm/via_drm.h>
44
45#include "via_dmablit.h"
46#include "via_drv.h"
47
48#define VIA_PGDN(x) (((unsigned long)(x)) & PAGE_MASK)
49#define VIA_PGOFF(x) (((unsigned long)(x)) & ~PAGE_MASK)
50#define VIA_PFN(x) ((unsigned long)(x) >> PAGE_SHIFT)
51
52typedef struct _drm_via_descriptor {
53 uint32_t mem_addr;
54 uint32_t dev_addr;
55 uint32_t size;
56 uint32_t next;
57} drm_via_descriptor_t;
58
59
60/*
61 * Unmap a DMA mapping.
62 */
63
64
65
66static void
67via_unmap_blit_from_device(struct pci_dev *pdev, drm_via_sg_info_t *vsg)
68{
69 int num_desc = vsg->num_desc;
70 unsigned cur_descriptor_page = num_desc / vsg->descriptors_per_page;
71 unsigned descriptor_this_page = num_desc % vsg->descriptors_per_page;
72 drm_via_descriptor_t *desc_ptr = vsg->desc_pages[cur_descriptor_page] +
73 descriptor_this_page;
74 dma_addr_t next = vsg->chain_start;
75
76 while (num_desc--) {
77 if (descriptor_this_page-- == 0) {
78 cur_descriptor_page--;
79 descriptor_this_page = vsg->descriptors_per_page - 1;
80 desc_ptr = vsg->desc_pages[cur_descriptor_page] +
81 descriptor_this_page;
82 }
83 dma_unmap_single(&pdev->dev, next, sizeof(*desc_ptr), DMA_TO_DEVICE);
84 dma_unmap_page(&pdev->dev, desc_ptr->mem_addr, desc_ptr->size, vsg->direction);
85 next = (dma_addr_t) desc_ptr->next;
86 desc_ptr--;
87 }
88}
89
90/*
91 * If mode = 0, count how many descriptors are needed.
92 * If mode = 1, Map the DMA pages for the device, put together and map also the descriptors.
93 * Descriptors are run in reverse order by the hardware because we are not allowed to update the
94 * 'next' field without syncing calls when the descriptor is already mapped.
95 */
96
97static void
98via_map_blit_for_device(struct pci_dev *pdev,
99 const drm_via_dmablit_t *xfer,
100 drm_via_sg_info_t *vsg,
101 int mode)
102{
103 unsigned cur_descriptor_page = 0;
104 unsigned num_descriptors_this_page = 0;
105 unsigned char *mem_addr = xfer->mem_addr;
106 unsigned char *cur_mem;
107 unsigned char *first_addr = (unsigned char *)VIA_PGDN(mem_addr);
108 uint32_t fb_addr = xfer->fb_addr;
109 uint32_t cur_fb;
110 unsigned long line_len;
111 unsigned remaining_len;
112 int num_desc = 0;
113 int cur_line;
114 dma_addr_t next = 0 | VIA_DMA_DPR_EC;
115 drm_via_descriptor_t *desc_ptr = NULL;
116
117 if (mode == 1)
118 desc_ptr = vsg->desc_pages[cur_descriptor_page];
119
120 for (cur_line = 0; cur_line < xfer->num_lines; ++cur_line) {
121
122 line_len = xfer->line_length;
123 cur_fb = fb_addr;
124 cur_mem = mem_addr;
125
126 while (line_len > 0) {
127
128 remaining_len = min(PAGE_SIZE-VIA_PGOFF(cur_mem), line_len);
129 line_len -= remaining_len;
130
131 if (mode == 1) {
132 desc_ptr->mem_addr =
133 dma_map_page(&pdev->dev,
134 vsg->pages[VIA_PFN(cur_mem) -
135 VIA_PFN(first_addr)],
136 VIA_PGOFF(cur_mem), remaining_len,
137 vsg->direction);
138 desc_ptr->dev_addr = cur_fb;
139
140 desc_ptr->size = remaining_len;
141 desc_ptr->next = (uint32_t) next;
142 next = dma_map_single(&pdev->dev, desc_ptr, sizeof(*desc_ptr),
143 DMA_TO_DEVICE);
144 desc_ptr++;
145 if (++num_descriptors_this_page >= vsg->descriptors_per_page) {
146 num_descriptors_this_page = 0;
147 desc_ptr = vsg->desc_pages[++cur_descriptor_page];
148 }
149 }
150
151 num_desc++;
152 cur_mem += remaining_len;
153 cur_fb += remaining_len;
154 }
155
156 mem_addr += xfer->mem_stride;
157 fb_addr += xfer->fb_stride;
158 }
159
160 if (mode == 1) {
161 vsg->chain_start = next;
162 vsg->state = dr_via_device_mapped;
163 }
164 vsg->num_desc = num_desc;
165}
166
167/*
168 * Function that frees up all resources for a blit. It is usable even if the
169 * blit info has only been partially built as long as the status enum is consistent
170 * with the actual status of the used resources.
171 */
172
173
174static void
175via_free_sg_info(struct pci_dev *pdev, drm_via_sg_info_t *vsg)
176{
177 int i;
178
179 switch (vsg->state) {
180 case dr_via_device_mapped:
181 via_unmap_blit_from_device(pdev, vsg);
182 fallthrough;
183 case dr_via_desc_pages_alloc:
184 for (i = 0; i < vsg->num_desc_pages; ++i) {
185 if (vsg->desc_pages[i] != NULL)
186 free_page((unsigned long)vsg->desc_pages[i]);
187 }
188 kfree(vsg->desc_pages);
189 fallthrough;
190 case dr_via_pages_locked:
191 unpin_user_pages_dirty_lock(vsg->pages, vsg->num_pages,
192 (vsg->direction == DMA_FROM_DEVICE));
193 fallthrough;
194 case dr_via_pages_alloc:
195 vfree(vsg->pages);
196 fallthrough;
197 default:
198 vsg->state = dr_via_sg_init;
199 }
200 vfree(vsg->bounce_buffer);
201 vsg->bounce_buffer = NULL;
202 vsg->free_on_sequence = 0;
203}
204
205/*
206 * Fire a blit engine.
207 */
208
209static void
210via_fire_dmablit(struct drm_device *dev, drm_via_sg_info_t *vsg, int engine)
211{
212 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
213
214 via_write(dev_priv, VIA_PCI_DMA_MAR0 + engine*0x10, 0);
215 via_write(dev_priv, VIA_PCI_DMA_DAR0 + engine*0x10, 0);
216 via_write(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_DD | VIA_DMA_CSR_TD |
217 VIA_DMA_CSR_DE);
218 via_write(dev_priv, VIA_PCI_DMA_MR0 + engine*0x04, VIA_DMA_MR_CM | VIA_DMA_MR_TDIE);
219 via_write(dev_priv, VIA_PCI_DMA_BCR0 + engine*0x10, 0);
220 via_write(dev_priv, VIA_PCI_DMA_DPR0 + engine*0x10, vsg->chain_start);
221 wmb();
222 via_write(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_DE | VIA_DMA_CSR_TS);
223 via_read(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04);
224}
225
226/*
227 * Obtain a page pointer array and lock all pages into system memory. A segmentation violation will
228 * occur here if the calling user does not have access to the submitted address.
229 */
230
231static int
232via_lock_all_dma_pages(drm_via_sg_info_t *vsg, drm_via_dmablit_t *xfer)
233{
234 int ret;
235 unsigned long first_pfn = VIA_PFN(xfer->mem_addr);
236 vsg->num_pages = VIA_PFN(xfer->mem_addr + (xfer->num_lines * xfer->mem_stride - 1)) -
237 first_pfn + 1;
238
239 vsg->pages = vzalloc(array_size(sizeof(struct page *), vsg->num_pages));
240 if (NULL == vsg->pages)
241 return -ENOMEM;
242 ret = pin_user_pages_fast((unsigned long)xfer->mem_addr,
243 vsg->num_pages,
244 vsg->direction == DMA_FROM_DEVICE ? FOLL_WRITE : 0,
245 vsg->pages);
246 if (ret != vsg->num_pages) {
247 if (ret < 0)
248 return ret;
249 vsg->state = dr_via_pages_locked;
250 return -EINVAL;
251 }
252 vsg->state = dr_via_pages_locked;
253 DRM_DEBUG("DMA pages locked\n");
254 return 0;
255}
256
257/*
258 * Allocate DMA capable memory for the blit descriptor chain, and an array that keeps track of the
259 * pages we allocate. We don't want to use kmalloc for the descriptor chain because it may be
260 * quite large for some blits, and pages don't need to be contiguous.
261 */
262
263static int
264via_alloc_desc_pages(drm_via_sg_info_t *vsg)
265{
266 int i;
267
268 vsg->descriptors_per_page = PAGE_SIZE / sizeof(drm_via_descriptor_t);
269 vsg->num_desc_pages = (vsg->num_desc + vsg->descriptors_per_page - 1) /
270 vsg->descriptors_per_page;
271
272 if (NULL == (vsg->desc_pages = kcalloc(vsg->num_desc_pages, sizeof(void *), GFP_KERNEL)))
273 return -ENOMEM;
274
275 vsg->state = dr_via_desc_pages_alloc;
276 for (i = 0; i < vsg->num_desc_pages; ++i) {
277 if (NULL == (vsg->desc_pages[i] =
278 (drm_via_descriptor_t *) __get_free_page(GFP_KERNEL)))
279 return -ENOMEM;
280 }
281 DRM_DEBUG("Allocated %d pages for %d descriptors.\n", vsg->num_desc_pages,
282 vsg->num_desc);
283 return 0;
284}
285
286static void
287via_abort_dmablit(struct drm_device *dev, int engine)
288{
289 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
290
291 via_write(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_TA);
292}
293
294static void
295via_dmablit_engine_off(struct drm_device *dev, int engine)
296{
297 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
298
299 via_write(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_TD | VIA_DMA_CSR_DD);
300}
301
302
303
304/*
305 * The dmablit part of the IRQ handler. Trying to do only reasonably fast things here.
306 * The rest, like unmapping and freeing memory for done blits is done in a separate workqueue
307 * task. Basically the task of the interrupt handler is to submit a new blit to the engine, while
308 * the workqueue task takes care of processing associated with the old blit.
309 */
310
311void
312via_dmablit_handler(struct drm_device *dev, int engine, int from_irq)
313{
314 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
315 drm_via_blitq_t *blitq = dev_priv->blit_queues + engine;
316 int cur;
317 int done_transfer;
318 unsigned long irqsave = 0;
319 uint32_t status = 0;
320
321 DRM_DEBUG("DMA blit handler called. engine = %d, from_irq = %d, blitq = 0x%lx\n",
322 engine, from_irq, (unsigned long) blitq);
323
324 if (from_irq)
325 spin_lock(&blitq->blit_lock);
326 else
327 spin_lock_irqsave(&blitq->blit_lock, irqsave);
328
329 done_transfer = blitq->is_active &&
330 ((status = via_read(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04)) & VIA_DMA_CSR_TD);
331 done_transfer = done_transfer || (blitq->aborting && !(status & VIA_DMA_CSR_DE));
332
333 cur = blitq->cur;
334 if (done_transfer) {
335
336 blitq->blits[cur]->aborted = blitq->aborting;
337 blitq->done_blit_handle++;
338 wake_up(blitq->blit_queue + cur);
339
340 cur++;
341 if (cur >= VIA_NUM_BLIT_SLOTS)
342 cur = 0;
343 blitq->cur = cur;
344
345 /*
346 * Clear transfer done flag.
347 */
348
349 via_write(dev_priv, VIA_PCI_DMA_CSR0 + engine*0x04, VIA_DMA_CSR_TD);
350
351 blitq->is_active = 0;
352 blitq->aborting = 0;
353 schedule_work(&blitq->wq);
354
355 } else if (blitq->is_active && time_after_eq(jiffies, blitq->end)) {
356
357 /*
358 * Abort transfer after one second.
359 */
360
361 via_abort_dmablit(dev, engine);
362 blitq->aborting = 1;
363 blitq->end = jiffies + HZ;
364 }
365
366 if (!blitq->is_active) {
367 if (blitq->num_outstanding) {
368 via_fire_dmablit(dev, blitq->blits[cur], engine);
369 blitq->is_active = 1;
370 blitq->cur = cur;
371 blitq->num_outstanding--;
372 blitq->end = jiffies + HZ;
373 if (!timer_pending(&blitq->poll_timer))
374 mod_timer(&blitq->poll_timer, jiffies + 1);
375 } else {
376 if (timer_pending(&blitq->poll_timer))
377 del_timer(&blitq->poll_timer);
378 via_dmablit_engine_off(dev, engine);
379 }
380 }
381
382 if (from_irq)
383 spin_unlock(&blitq->blit_lock);
384 else
385 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
386}
387
388
389
390/*
391 * Check whether this blit is still active, performing necessary locking.
392 */
393
394static int
395via_dmablit_active(drm_via_blitq_t *blitq, int engine, uint32_t handle, wait_queue_head_t **queue)
396{
397 unsigned long irqsave;
398 uint32_t slot;
399 int active;
400
401 spin_lock_irqsave(&blitq->blit_lock, irqsave);
402
403 /*
404 * Allow for handle wraparounds.
405 */
406
407 active = ((blitq->done_blit_handle - handle) > (1 << 23)) &&
408 ((blitq->cur_blit_handle - handle) <= (1 << 23));
409
410 if (queue && active) {
411 slot = handle - blitq->done_blit_handle + blitq->cur - 1;
412 if (slot >= VIA_NUM_BLIT_SLOTS)
413 slot -= VIA_NUM_BLIT_SLOTS;
414 *queue = blitq->blit_queue + slot;
415 }
416
417 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
418
419 return active;
420}
421
422/*
423 * Sync. Wait for at least three seconds for the blit to be performed.
424 */
425
426static int
427via_dmablit_sync(struct drm_device *dev, uint32_t handle, int engine)
428{
429
430 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
431 drm_via_blitq_t *blitq = dev_priv->blit_queues + engine;
432 wait_queue_head_t *queue;
433 int ret = 0;
434
435 if (via_dmablit_active(blitq, engine, handle, &queue)) {
436 VIA_WAIT_ON(ret, *queue, 3 * HZ,
437 !via_dmablit_active(blitq, engine, handle, NULL));
438 }
439 DRM_DEBUG("DMA blit sync handle 0x%x engine %d returned %d\n",
440 handle, engine, ret);
441
442 return ret;
443}
444
445
446/*
447 * A timer that regularly polls the blit engine in cases where we don't have interrupts:
448 * a) Broken hardware (typically those that don't have any video capture facility).
449 * b) Blit abort. The hardware doesn't send an interrupt when a blit is aborted.
450 * The timer and hardware IRQ's can and do work in parallel. If the hardware has
451 * irqs, it will shorten the latency somewhat.
452 */
453
454
455
456static void
457via_dmablit_timer(struct timer_list *t)
458{
459 drm_via_blitq_t *blitq = from_timer(blitq, t, poll_timer);
460 struct drm_device *dev = blitq->dev;
461 int engine = (int)
462 (blitq - ((drm_via_private_t *)dev->dev_private)->blit_queues);
463
464 DRM_DEBUG("Polling timer called for engine %d, jiffies %lu\n", engine,
465 (unsigned long) jiffies);
466
467 via_dmablit_handler(dev, engine, 0);
468
469 if (!timer_pending(&blitq->poll_timer)) {
470 mod_timer(&blitq->poll_timer, jiffies + 1);
471
472 /*
473 * Rerun handler to delete timer if engines are off, and
474 * to shorten abort latency. This is a little nasty.
475 */
476
477 via_dmablit_handler(dev, engine, 0);
478
479 }
480}
481
482
483
484
485/*
486 * Workqueue task that frees data and mappings associated with a blit.
487 * Also wakes up waiting processes. Each of these tasks handles one
488 * blit engine only and may not be called on each interrupt.
489 */
490
491
492static void
493via_dmablit_workqueue(struct work_struct *work)
494{
495 drm_via_blitq_t *blitq = container_of(work, drm_via_blitq_t, wq);
496 struct drm_device *dev = blitq->dev;
497 unsigned long irqsave;
498 drm_via_sg_info_t *cur_sg;
499 int cur_released;
500
501
502 DRM_DEBUG("Workqueue task called for blit engine %ld\n", (unsigned long)
503 (blitq - ((drm_via_private_t *)dev->dev_private)->blit_queues));
504
505 spin_lock_irqsave(&blitq->blit_lock, irqsave);
506
507 while (blitq->serviced != blitq->cur) {
508
509 cur_released = blitq->serviced++;
510
511 DRM_DEBUG("Releasing blit slot %d\n", cur_released);
512
513 if (blitq->serviced >= VIA_NUM_BLIT_SLOTS)
514 blitq->serviced = 0;
515
516 cur_sg = blitq->blits[cur_released];
517 blitq->num_free++;
518
519 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
520
521 wake_up(&blitq->busy_queue);
522
523 via_free_sg_info(dev->pdev, cur_sg);
524 kfree(cur_sg);
525
526 spin_lock_irqsave(&blitq->blit_lock, irqsave);
527 }
528
529 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
530}
531
532
533/*
534 * Init all blit engines. Currently we use two, but some hardware have 4.
535 */
536
537
538void
539via_init_dmablit(struct drm_device *dev)
540{
541 int i, j;
542 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
543 drm_via_blitq_t *blitq;
544
545 pci_set_master(dev->pdev);
546
547 for (i = 0; i < VIA_NUM_BLIT_ENGINES; ++i) {
548 blitq = dev_priv->blit_queues + i;
549 blitq->dev = dev;
550 blitq->cur_blit_handle = 0;
551 blitq->done_blit_handle = 0;
552 blitq->head = 0;
553 blitq->cur = 0;
554 blitq->serviced = 0;
555 blitq->num_free = VIA_NUM_BLIT_SLOTS - 1;
556 blitq->num_outstanding = 0;
557 blitq->is_active = 0;
558 blitq->aborting = 0;
559 spin_lock_init(&blitq->blit_lock);
560 for (j = 0; j < VIA_NUM_BLIT_SLOTS; ++j)
561 init_waitqueue_head(blitq->blit_queue + j);
562 init_waitqueue_head(&blitq->busy_queue);
563 INIT_WORK(&blitq->wq, via_dmablit_workqueue);
564 timer_setup(&blitq->poll_timer, via_dmablit_timer, 0);
565 }
566}
567
568/*
569 * Build all info and do all mappings required for a blit.
570 */
571
572
573static int
574via_build_sg_info(struct drm_device *dev, drm_via_sg_info_t *vsg, drm_via_dmablit_t *xfer)
575{
576 int draw = xfer->to_fb;
577 int ret = 0;
578
579 vsg->direction = (draw) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
580 vsg->bounce_buffer = NULL;
581
582 vsg->state = dr_via_sg_init;
583
584 if (xfer->num_lines <= 0 || xfer->line_length <= 0) {
585 DRM_ERROR("Zero size bitblt.\n");
586 return -EINVAL;
587 }
588
589 /*
590 * Below check is a driver limitation, not a hardware one. We
591 * don't want to lock unused pages, and don't want to incoporate the
592 * extra logic of avoiding them. Make sure there are no.
593 * (Not a big limitation anyway.)
594 */
595
596 if ((xfer->mem_stride - xfer->line_length) > 2*PAGE_SIZE) {
597 DRM_ERROR("Too large system memory stride. Stride: %d, "
598 "Length: %d\n", xfer->mem_stride, xfer->line_length);
599 return -EINVAL;
600 }
601
602 if ((xfer->mem_stride == xfer->line_length) &&
603 (xfer->fb_stride == xfer->line_length)) {
604 xfer->mem_stride *= xfer->num_lines;
605 xfer->line_length = xfer->mem_stride;
606 xfer->fb_stride = xfer->mem_stride;
607 xfer->num_lines = 1;
608 }
609
610 /*
611 * Don't lock an arbitrary large number of pages, since that causes a
612 * DOS security hole.
613 */
614
615 if (xfer->num_lines > 2048 || (xfer->num_lines*xfer->mem_stride > (2048*2048*4))) {
616 DRM_ERROR("Too large PCI DMA bitblt.\n");
617 return -EINVAL;
618 }
619
620 /*
621 * we allow a negative fb stride to allow flipping of images in
622 * transfer.
623 */
624
625 if (xfer->mem_stride < xfer->line_length ||
626 abs(xfer->fb_stride) < xfer->line_length) {
627 DRM_ERROR("Invalid frame-buffer / memory stride.\n");
628 return -EINVAL;
629 }
630
631 /*
632 * A hardware bug seems to be worked around if system memory addresses start on
633 * 16 byte boundaries. This seems a bit restrictive however. VIA is contacted
634 * about this. Meanwhile, impose the following restrictions:
635 */
636
637#ifdef VIA_BUGFREE
638 if ((((unsigned long)xfer->mem_addr & 3) != ((unsigned long)xfer->fb_addr & 3)) ||
639 ((xfer->num_lines > 1) && ((xfer->mem_stride & 3) != (xfer->fb_stride & 3)))) {
640 DRM_ERROR("Invalid DRM bitblt alignment.\n");
641 return -EINVAL;
642 }
643#else
644 if ((((unsigned long)xfer->mem_addr & 15) ||
645 ((unsigned long)xfer->fb_addr & 3)) ||
646 ((xfer->num_lines > 1) &&
647 ((xfer->mem_stride & 15) || (xfer->fb_stride & 3)))) {
648 DRM_ERROR("Invalid DRM bitblt alignment.\n");
649 return -EINVAL;
650 }
651#endif
652
653 if (0 != (ret = via_lock_all_dma_pages(vsg, xfer))) {
654 DRM_ERROR("Could not lock DMA pages.\n");
655 via_free_sg_info(dev->pdev, vsg);
656 return ret;
657 }
658
659 via_map_blit_for_device(dev->pdev, xfer, vsg, 0);
660 if (0 != (ret = via_alloc_desc_pages(vsg))) {
661 DRM_ERROR("Could not allocate DMA descriptor pages.\n");
662 via_free_sg_info(dev->pdev, vsg);
663 return ret;
664 }
665 via_map_blit_for_device(dev->pdev, xfer, vsg, 1);
666
667 return 0;
668}
669
670
671/*
672 * Reserve one free slot in the blit queue. Will wait for one second for one
673 * to become available. Otherwise -EBUSY is returned.
674 */
675
676static int
677via_dmablit_grab_slot(drm_via_blitq_t *blitq, int engine)
678{
679 int ret = 0;
680 unsigned long irqsave;
681
682 DRM_DEBUG("Num free is %d\n", blitq->num_free);
683 spin_lock_irqsave(&blitq->blit_lock, irqsave);
684 while (blitq->num_free == 0) {
685 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
686
687 VIA_WAIT_ON(ret, blitq->busy_queue, HZ, blitq->num_free > 0);
688 if (ret)
689 return (-EINTR == ret) ? -EAGAIN : ret;
690
691 spin_lock_irqsave(&blitq->blit_lock, irqsave);
692 }
693
694 blitq->num_free--;
695 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
696
697 return 0;
698}
699
700/*
701 * Hand back a free slot if we changed our mind.
702 */
703
704static void
705via_dmablit_release_slot(drm_via_blitq_t *blitq)
706{
707 unsigned long irqsave;
708
709 spin_lock_irqsave(&blitq->blit_lock, irqsave);
710 blitq->num_free++;
711 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
712 wake_up(&blitq->busy_queue);
713}
714
715/*
716 * Grab a free slot. Build blit info and queue a blit.
717 */
718
719
720static int
721via_dmablit(struct drm_device *dev, drm_via_dmablit_t *xfer)
722{
723 drm_via_private_t *dev_priv = (drm_via_private_t *)dev->dev_private;
724 drm_via_sg_info_t *vsg;
725 drm_via_blitq_t *blitq;
726 int ret;
727 int engine;
728 unsigned long irqsave;
729
730 if (dev_priv == NULL) {
731 DRM_ERROR("Called without initialization.\n");
732 return -EINVAL;
733 }
734
735 engine = (xfer->to_fb) ? 0 : 1;
736 blitq = dev_priv->blit_queues + engine;
737 if (0 != (ret = via_dmablit_grab_slot(blitq, engine)))
738 return ret;
739 if (NULL == (vsg = kmalloc(sizeof(*vsg), GFP_KERNEL))) {
740 via_dmablit_release_slot(blitq);
741 return -ENOMEM;
742 }
743 if (0 != (ret = via_build_sg_info(dev, vsg, xfer))) {
744 via_dmablit_release_slot(blitq);
745 kfree(vsg);
746 return ret;
747 }
748 spin_lock_irqsave(&blitq->blit_lock, irqsave);
749
750 blitq->blits[blitq->head++] = vsg;
751 if (blitq->head >= VIA_NUM_BLIT_SLOTS)
752 blitq->head = 0;
753 blitq->num_outstanding++;
754 xfer->sync.sync_handle = ++blitq->cur_blit_handle;
755
756 spin_unlock_irqrestore(&blitq->blit_lock, irqsave);
757 xfer->sync.engine = engine;
758
759 via_dmablit_handler(dev, engine, 0);
760
761 return 0;
762}
763
764/*
765 * Sync on a previously submitted blit. Note that the X server use signals extensively, and
766 * that there is a very big probability that this IOCTL will be interrupted by a signal. In that
767 * case it returns with -EAGAIN for the signal to be delivered.
768 * The caller should then reissue the IOCTL. This is similar to what is being done for drmGetLock().
769 */
770
771int
772via_dma_blit_sync(struct drm_device *dev, void *data, struct drm_file *file_priv)
773{
774 drm_via_blitsync_t *sync = data;
775 int err;
776
777 if (sync->engine >= VIA_NUM_BLIT_ENGINES)
778 return -EINVAL;
779
780 err = via_dmablit_sync(dev, sync->sync_handle, sync->engine);
781
782 if (-EINTR == err)
783 err = -EAGAIN;
784
785 return err;
786}
787
788
789/*
790 * Queue a blit and hand back a handle to be used for sync. This IOCTL may be interrupted by a signal
791 * while waiting for a free slot in the blit queue. In that case it returns with -EAGAIN and should
792 * be reissued. See the above IOCTL code.
793 */
794
795int
796via_dma_blit(struct drm_device *dev, void *data, struct drm_file *file_priv)
797{
798 drm_via_dmablit_t *xfer = data;
799 int err;
800
801 err = via_dmablit(dev, xfer);
802
803 return err;
804}