[PATCH] drm: via: fix sparse warnings
[safe/jmp/linux-2.6] / drivers / char / drm / via_dma.c
1 /* via_dma.c -- DMA support for the VIA Unichrome/Pro
2  * 
3  * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
4  * All Rights Reserved.
5  *
6  * Copyright 2004 Digeo, Inc., Palo Alto, CA, U.S.A.
7  * All Rights Reserved.
8  * 
9  * Copyright 2004 The Unichrome project.
10  * All Rights Reserved.
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a
13  * copy of this software and associated documentation files (the "Software"),
14  * to deal in the Software without restriction, including without limitation
15  * the rights to use, copy, modify, merge, publish, distribute, sub license,
16  * and/or sell copies of the Software, and to permit persons to whom the
17  * Software is furnished to do so, subject to the following conditions:
18  *
19  * The above copyright notice and this permission notice (including the
20  * next paragraph) shall be included in all copies or substantial portions
21  * of the Software.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
24  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
25  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
26  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, 
27  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR 
28  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE 
29  * USE OR OTHER DEALINGS IN THE SOFTWARE.
30  *
31  * Authors: 
32  *    Tungsten Graphics, 
33  *    Erdi Chen, 
34  *    Thomas Hellstrom.
35  */
36
37 #include "drmP.h"
38 #include "drm.h"
39 #include "via_drm.h"
40 #include "via_drv.h"
41 #include "via_3d_reg.h"
42
43 #define CMDBUF_ALIGNMENT_SIZE   (0x100)
44 #define CMDBUF_ALIGNMENT_MASK   (0x0ff)
45
46 /* defines for VIA 3D registers */
47 #define VIA_REG_STATUS          0x400
48 #define VIA_REG_TRANSET         0x43C
49 #define VIA_REG_TRANSPACE       0x440
50
51 /* VIA_REG_STATUS(0x400): Engine Status */
52 #define VIA_CMD_RGTR_BUSY       0x00000080      /* Command Regulator is busy */
53 #define VIA_2D_ENG_BUSY         0x00000001      /* 2D Engine is busy */
54 #define VIA_3D_ENG_BUSY         0x00000002      /* 3D Engine is busy */
55 #define VIA_VR_QUEUE_BUSY       0x00020000      /* Virtual Queue is busy */
56
57 #define SetReg2DAGP(nReg, nData) {                              \
58         *((uint32_t *)(vb)) = ((nReg) >> 2) | HALCYON_HEADER1;  \
59         *((uint32_t *)(vb) + 1) = (nData);                      \
60         vb = ((uint32_t *)vb) + 2;                              \
61         dev_priv->dma_low +=8;                                  \
62 }
63
64 #define via_flush_write_combine() DRM_MEMORYBARRIER() 
65
66 #define VIA_OUT_RING_QW(w1,w2)                  \
67         *vb++ = (w1);                           \
68         *vb++ = (w2);                           \
69         dev_priv->dma_low += 8; 
70
71 static void via_cmdbuf_start(drm_via_private_t * dev_priv);
72 static void via_cmdbuf_pause(drm_via_private_t * dev_priv);
73 static void via_cmdbuf_reset(drm_via_private_t * dev_priv);
74 static void via_cmdbuf_rewind(drm_via_private_t * dev_priv);
75 static int via_wait_idle(drm_via_private_t * dev_priv);
76 static void via_pad_cache(drm_via_private_t *dev_priv, int qwords);
77
78
79 /*
80  * Free space in command buffer.
81  */
82
83 static uint32_t
84 via_cmdbuf_space(drm_via_private_t *dev_priv)
85 {
86         uint32_t agp_base = dev_priv->dma_offset + 
87                 (uint32_t) dev_priv->agpAddr;
88         uint32_t hw_addr = *(dev_priv->hw_addr_ptr) - agp_base;
89         
90         return ((hw_addr <= dev_priv->dma_low) ? 
91                 (dev_priv->dma_high + hw_addr - dev_priv->dma_low) : 
92                 (hw_addr - dev_priv->dma_low));
93 }
94
95 /*
96  * How much does the command regulator lag behind?
97  */
98
99 static uint32_t
100 via_cmdbuf_lag(drm_via_private_t *dev_priv)
101 {
102         uint32_t agp_base = dev_priv->dma_offset + 
103                 (uint32_t) dev_priv->agpAddr;
104         uint32_t hw_addr = *(dev_priv->hw_addr_ptr) - agp_base;
105         
106         return ((hw_addr <= dev_priv->dma_low) ? 
107                 (dev_priv->dma_low - hw_addr) : 
108                 (dev_priv->dma_wrap + dev_priv->dma_low - hw_addr));
109 }
110
111 /*
112  * Check that the given size fits in the buffer, otherwise wait.
113  */
114
115 static inline int
116 via_cmdbuf_wait(drm_via_private_t * dev_priv, unsigned int size)
117 {
118         uint32_t agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
119         uint32_t cur_addr, hw_addr, next_addr;
120         volatile uint32_t *hw_addr_ptr;
121         uint32_t count;
122         hw_addr_ptr = dev_priv->hw_addr_ptr;
123         cur_addr = dev_priv->dma_low;
124         next_addr = cur_addr + size + 512*1024;
125         count = 1000000;
126         do {
127                 hw_addr = *hw_addr_ptr - agp_base;
128                 if (count-- == 0) {
129                         DRM_ERROR("via_cmdbuf_wait timed out hw %x cur_addr %x next_addr %x\n",
130                                   hw_addr, cur_addr, next_addr);
131                         return -1;
132                 }
133         } while ((cur_addr < hw_addr) && (next_addr >= hw_addr));
134         return 0;
135 }
136
137
138 /*
139  * Checks whether buffer head has reach the end. Rewind the ring buffer
140  * when necessary.
141  *
142  * Returns virtual pointer to ring buffer.
143  */
144
145 static inline uint32_t *via_check_dma(drm_via_private_t * dev_priv,
146                                       unsigned int size)
147 {
148         if ((dev_priv->dma_low + size + 4*CMDBUF_ALIGNMENT_SIZE) > dev_priv->dma_high) {
149                 via_cmdbuf_rewind(dev_priv);
150         }
151         if (via_cmdbuf_wait(dev_priv, size) != 0) {
152                 return NULL;
153         }
154
155         return (uint32_t *) (dev_priv->dma_ptr + dev_priv->dma_low);
156 }
157
158 int via_dma_cleanup(drm_device_t * dev)
159 {
160         if (dev->dev_private) {
161                 drm_via_private_t *dev_priv =
162                         (drm_via_private_t *) dev->dev_private;
163
164                 if (dev_priv->ring.virtual_start) {
165                         via_cmdbuf_reset(dev_priv);
166
167                         drm_core_ioremapfree(&dev_priv->ring.map, dev);
168                         dev_priv->ring.virtual_start = NULL;
169                 }
170
171         }
172
173         return 0;
174 }
175
176 static int via_initialize(drm_device_t * dev,
177                           drm_via_private_t * dev_priv,
178                           drm_via_dma_init_t * init)
179 {
180         if (!dev_priv || !dev_priv->mmio) {
181                 DRM_ERROR("via_dma_init called before via_map_init\n");
182                 return DRM_ERR(EFAULT);
183         }
184
185         if (dev_priv->ring.virtual_start != NULL) {
186                 DRM_ERROR("%s called again without calling cleanup\n",
187                           __FUNCTION__);
188                 return DRM_ERR(EFAULT);
189         }
190
191         if (!dev->agp || !dev->agp->base) {
192                 DRM_ERROR("%s called with no agp memory available\n", 
193                           __FUNCTION__);
194                 return DRM_ERR(EFAULT);
195         }
196
197         dev_priv->ring.map.offset = dev->agp->base + init->offset;
198         dev_priv->ring.map.size = init->size;
199         dev_priv->ring.map.type = 0;
200         dev_priv->ring.map.flags = 0;
201         dev_priv->ring.map.mtrr = 0;
202
203         drm_core_ioremap(&dev_priv->ring.map, dev);
204
205         if (dev_priv->ring.map.handle == NULL) {
206                 via_dma_cleanup(dev);
207                 DRM_ERROR("can not ioremap virtual address for"
208                           " ring buffer\n");
209                 return DRM_ERR(ENOMEM);
210         }
211
212         dev_priv->ring.virtual_start = dev_priv->ring.map.handle;
213
214         dev_priv->dma_ptr = dev_priv->ring.virtual_start;
215         dev_priv->dma_low = 0;
216         dev_priv->dma_high = init->size;
217         dev_priv->dma_wrap = init->size;
218         dev_priv->dma_offset = init->offset;
219         dev_priv->last_pause_ptr = NULL;
220         dev_priv->hw_addr_ptr = dev_priv->mmio->handle + init->reg_pause_addr;
221
222         via_cmdbuf_start(dev_priv);
223
224         return 0;
225 }
226
227 int via_dma_init(DRM_IOCTL_ARGS)
228 {
229         DRM_DEVICE;
230         drm_via_private_t *dev_priv = (drm_via_private_t *) dev->dev_private;
231         drm_via_dma_init_t init;
232         int retcode = 0;
233
234         DRM_COPY_FROM_USER_IOCTL(init, (drm_via_dma_init_t __user *) data,
235                                  sizeof(init));
236
237         switch (init.func) {
238         case VIA_INIT_DMA:
239                 if (!capable(CAP_SYS_ADMIN))
240                         retcode = DRM_ERR(EPERM);
241                 else
242                         retcode = via_initialize(dev, dev_priv, &init);
243                 break;
244         case VIA_CLEANUP_DMA:
245                 if (!capable(CAP_SYS_ADMIN))
246                         retcode = DRM_ERR(EPERM);
247                 else
248                         retcode = via_dma_cleanup(dev);
249                 break;
250         case VIA_DMA_INITIALIZED:
251                 retcode = (dev_priv->ring.virtual_start != NULL) ? 
252                         0: DRM_ERR( EFAULT );
253                 break;
254         default:
255                 retcode = DRM_ERR(EINVAL);
256                 break;
257         }
258
259         return retcode;
260 }
261
262
263
264 static int via_dispatch_cmdbuffer(drm_device_t * dev, drm_via_cmdbuffer_t * cmd)
265 {
266         drm_via_private_t *dev_priv;
267         uint32_t *vb;
268         int ret;
269
270         dev_priv = (drm_via_private_t *) dev->dev_private;
271
272         if (dev_priv->ring.virtual_start == NULL) {
273                 DRM_ERROR("%s called without initializing AGP ring buffer.\n",
274                           __FUNCTION__);
275                 return DRM_ERR(EFAULT);
276         }
277
278         if (cmd->size > VIA_PCI_BUF_SIZE) {
279                 return DRM_ERR(ENOMEM);
280         } 
281
282
283         if (DRM_COPY_FROM_USER(dev_priv->pci_buf, cmd->buf, cmd->size))
284                 return DRM_ERR(EFAULT);
285
286         /*
287          * Running this function on AGP memory is dead slow. Therefore
288          * we run it on a temporary cacheable system memory buffer and
289          * copy it to AGP memory when ready.
290          */
291
292                 
293         if ((ret = via_verify_command_stream((uint32_t *)dev_priv->pci_buf, cmd->size, dev, 1))) {
294                 return ret;
295         }
296         
297         
298         vb = via_check_dma(dev_priv, (cmd->size < 0x100) ? 0x102 : cmd->size);
299         if (vb == NULL) {
300                 return DRM_ERR(EAGAIN);
301         }
302
303         memcpy(vb, dev_priv->pci_buf, cmd->size);
304         
305         dev_priv->dma_low += cmd->size;
306
307         /*
308          * Small submissions somehow stalls the CPU. (AGP cache effects?)
309          * pad to greater size.
310          */
311
312         if (cmd->size < 0x100)
313           via_pad_cache(dev_priv,(0x100 - cmd->size) >> 3);
314         via_cmdbuf_pause(dev_priv);
315
316         return 0;
317 }
318
319 int via_driver_dma_quiescent(drm_device_t * dev)
320 {
321         drm_via_private_t *dev_priv = dev->dev_private;
322
323         if (!via_wait_idle(dev_priv)) {
324                 return DRM_ERR(EBUSY);
325         }
326         return 0;
327 }
328
329 int via_flush_ioctl(DRM_IOCTL_ARGS)
330 {
331         DRM_DEVICE;
332
333         LOCK_TEST_WITH_RETURN( dev, filp );
334
335         return via_driver_dma_quiescent(dev);
336 }
337
338 int via_cmdbuffer(DRM_IOCTL_ARGS)
339 {
340         DRM_DEVICE;
341         drm_via_cmdbuffer_t cmdbuf;
342         int ret;
343
344         LOCK_TEST_WITH_RETURN( dev, filp );
345
346         DRM_COPY_FROM_USER_IOCTL(cmdbuf, (drm_via_cmdbuffer_t __user *) data,
347                                  sizeof(cmdbuf));
348
349         DRM_DEBUG("via cmdbuffer, buf %p size %lu\n", cmdbuf.buf, cmdbuf.size);
350
351         ret = via_dispatch_cmdbuffer(dev, &cmdbuf);
352         if (ret) {
353                 return ret;
354         }
355
356         return 0;
357 }
358
359 extern int 
360 via_parse_command_stream(drm_device_t *dev, const uint32_t * buf, unsigned int size);
361 static int via_dispatch_pci_cmdbuffer(drm_device_t * dev,
362                                       drm_via_cmdbuffer_t * cmd)
363 {
364         drm_via_private_t *dev_priv = dev->dev_private;
365         int ret;
366
367         if (cmd->size > VIA_PCI_BUF_SIZE) {
368                 return DRM_ERR(ENOMEM);
369         } 
370         if (DRM_COPY_FROM_USER(dev_priv->pci_buf, cmd->buf, cmd->size))
371                 return DRM_ERR(EFAULT);
372         
373         if ((ret = via_verify_command_stream((uint32_t *)dev_priv->pci_buf, cmd->size, dev, 0))) {
374                 return ret;
375         }
376         
377         ret = via_parse_command_stream(dev, (const uint32_t *)dev_priv->pci_buf, cmd->size);
378         return ret;
379 }
380
381 int via_pci_cmdbuffer(DRM_IOCTL_ARGS)
382 {
383         DRM_DEVICE;
384         drm_via_cmdbuffer_t cmdbuf;
385         int ret;
386
387         LOCK_TEST_WITH_RETURN( dev, filp );
388
389         DRM_COPY_FROM_USER_IOCTL(cmdbuf, (drm_via_cmdbuffer_t __user *) data,
390                                  sizeof(cmdbuf));
391
392         DRM_DEBUG("via_pci_cmdbuffer, buf %p size %lu\n", cmdbuf.buf,
393                   cmdbuf.size);
394
395         ret = via_dispatch_pci_cmdbuffer(dev, &cmdbuf);
396         if (ret) {
397                 return ret;
398         }
399
400         return 0;
401 }
402
403
404 static inline uint32_t *via_align_buffer(drm_via_private_t * dev_priv,
405                                          uint32_t * vb, int qw_count)
406 {
407         for (; qw_count > 0; --qw_count) {
408                 VIA_OUT_RING_QW(HC_DUMMY, HC_DUMMY);
409         }
410         return vb;
411 }
412
413
414 /*
415  * This function is used internally by ring buffer mangement code.
416  *
417  * Returns virtual pointer to ring buffer.
418  */
419 static inline uint32_t *via_get_dma(drm_via_private_t * dev_priv)
420 {
421         return (uint32_t *) (dev_priv->dma_ptr + dev_priv->dma_low);
422 }
423
424 /*
425  * Hooks a segment of data into the tail of the ring-buffer by
426  * modifying the pause address stored in the buffer itself. If
427  * the regulator has already paused, restart it.
428  */
429 static int via_hook_segment(drm_via_private_t *dev_priv,
430                             uint32_t pause_addr_hi, uint32_t pause_addr_lo,
431                             int no_pci_fire)
432 {
433         int paused, count;
434         volatile uint32_t *paused_at = dev_priv->last_pause_ptr;
435
436         via_flush_write_combine();
437         while(! *(via_get_dma(dev_priv)-1));
438         *dev_priv->last_pause_ptr = pause_addr_lo;
439         via_flush_write_combine();
440
441         /*
442          * The below statement is inserted to really force the flush.
443          * Not sure it is needed.
444          */
445
446         while(! *dev_priv->last_pause_ptr);
447         dev_priv->last_pause_ptr = via_get_dma(dev_priv) - 1;
448         while(! *dev_priv->last_pause_ptr);
449
450
451         paused = 0;
452         count = 20; 
453
454         while (!(paused = (VIA_READ(0x41c) & 0x80000000)) && count--);
455         if ((count <= 8) && (count >= 0)) {
456                 uint32_t rgtr, ptr;
457                 rgtr = *(dev_priv->hw_addr_ptr);
458                 ptr = ((char *)dev_priv->last_pause_ptr - dev_priv->dma_ptr) + 
459                         dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4 - 
460                         CMDBUF_ALIGNMENT_SIZE;
461                 if (rgtr <= ptr) {
462                         DRM_ERROR("Command regulator\npaused at count %d, address %x, "
463                                   "while current pause address is %x.\n"
464                                   "Please mail this message to "
465                                   "<unichrome-devel@lists.sourceforge.net>\n",
466                                   count, rgtr, ptr);
467                 }
468         }
469                 
470         if (paused && !no_pci_fire) {
471                 uint32_t rgtr,ptr;
472                 uint32_t ptr_low;
473
474                 count = 1000000;
475                 while ((VIA_READ(VIA_REG_STATUS) & VIA_CMD_RGTR_BUSY) && count--);
476                 
477                 rgtr = *(dev_priv->hw_addr_ptr);
478                 ptr = ((char *)paused_at - dev_priv->dma_ptr) + 
479                         dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr + 4;
480                 
481
482                 ptr_low = (ptr > 3*CMDBUF_ALIGNMENT_SIZE) ? 
483                         ptr - 3*CMDBUF_ALIGNMENT_SIZE : 0;
484                 if (rgtr <= ptr && rgtr >= ptr_low) {
485                         VIA_WRITE(VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
486                         VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_hi);
487                         VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_lo);
488                 } 
489         }
490         return paused;
491 }
492
493
494
495 static int via_wait_idle(drm_via_private_t * dev_priv)
496 {
497         int count = 10000000;
498         while (count-- && (VIA_READ(VIA_REG_STATUS) &
499                            (VIA_CMD_RGTR_BUSY | VIA_2D_ENG_BUSY |
500                             VIA_3D_ENG_BUSY))) ;
501         return count;
502 }
503
504 static uint32_t *via_align_cmd(drm_via_private_t * dev_priv, uint32_t cmd_type,
505                                uint32_t addr, uint32_t *cmd_addr_hi, 
506                                uint32_t *cmd_addr_lo,
507                                int skip_wait)
508 {
509         uint32_t agp_base;
510         uint32_t cmd_addr, addr_lo, addr_hi;
511         uint32_t *vb;
512         uint32_t qw_pad_count;
513
514         if (!skip_wait)
515                 via_cmdbuf_wait(dev_priv, 2*CMDBUF_ALIGNMENT_SIZE);
516
517         vb = via_get_dma(dev_priv);
518         VIA_OUT_RING_QW( HC_HEADER2 | ((VIA_REG_TRANSET >> 2) << 12) |
519                          (VIA_REG_TRANSPACE >> 2), HC_ParaType_PreCR << 16); 
520         agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
521         qw_pad_count = (CMDBUF_ALIGNMENT_SIZE >> 3) -
522                 ((dev_priv->dma_low & CMDBUF_ALIGNMENT_MASK) >> 3);
523
524         
525         cmd_addr = (addr) ? addr : 
526                 agp_base + dev_priv->dma_low - 8 + (qw_pad_count << 3);
527         addr_lo = ((HC_SubA_HAGPBpL << 24) | (cmd_type & HC_HAGPBpID_MASK) |
528                    (cmd_addr & HC_HAGPBpL_MASK));
529         addr_hi = ((HC_SubA_HAGPBpH << 24) | (cmd_addr >> 24));
530
531         vb = via_align_buffer(dev_priv, vb, qw_pad_count - 1);
532         VIA_OUT_RING_QW(*cmd_addr_hi = addr_hi, 
533                         *cmd_addr_lo = addr_lo);
534         return vb;
535 }
536
537
538
539
540 static void via_cmdbuf_start(drm_via_private_t * dev_priv)
541 {
542         uint32_t pause_addr_lo, pause_addr_hi;
543         uint32_t start_addr, start_addr_lo;
544         uint32_t end_addr, end_addr_lo;
545         uint32_t command;
546         uint32_t agp_base;
547
548
549         dev_priv->dma_low = 0;
550
551         agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
552         start_addr = agp_base;
553         end_addr = agp_base + dev_priv->dma_high;
554
555         start_addr_lo = ((HC_SubA_HAGPBstL << 24) | (start_addr & 0xFFFFFF));
556         end_addr_lo = ((HC_SubA_HAGPBendL << 24) | (end_addr & 0xFFFFFF));
557         command = ((HC_SubA_HAGPCMNT << 24) | (start_addr >> 24) |
558                    ((end_addr & 0xff000000) >> 16));
559
560         dev_priv->last_pause_ptr = 
561                 via_align_cmd(dev_priv, HC_HAGPBpID_PAUSE, 0, 
562                               &pause_addr_hi, & pause_addr_lo, 1) - 1;
563
564         via_flush_write_combine();
565         while(! *dev_priv->last_pause_ptr);
566
567         VIA_WRITE(VIA_REG_TRANSET, (HC_ParaType_PreCR << 16));
568         VIA_WRITE(VIA_REG_TRANSPACE, command);
569         VIA_WRITE(VIA_REG_TRANSPACE, start_addr_lo);
570         VIA_WRITE(VIA_REG_TRANSPACE, end_addr_lo);
571
572         VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_hi);
573         VIA_WRITE(VIA_REG_TRANSPACE, pause_addr_lo);
574
575         VIA_WRITE(VIA_REG_TRANSPACE, command | HC_HAGPCMNT_MASK);
576 }
577
578 static void via_pad_cache(drm_via_private_t *dev_priv, int qwords)
579 {
580         uint32_t *vb;
581
582         via_cmdbuf_wait(dev_priv, qwords + 2);
583         vb = via_get_dma(dev_priv);
584         VIA_OUT_RING_QW( HC_HEADER2, HC_ParaType_NotTex << 16);
585         via_align_buffer(dev_priv,vb,qwords);
586 }
587
588 static inline void via_dummy_bitblt(drm_via_private_t * dev_priv)
589 {
590         uint32_t *vb = via_get_dma(dev_priv);
591         SetReg2DAGP(0x0C, (0 | (0 << 16)));
592         SetReg2DAGP(0x10, 0 | (0 << 16));
593         SetReg2DAGP(0x0, 0x1 | 0x2000 | 0xAA000000); 
594 }
595
596
597 static void via_cmdbuf_jump(drm_via_private_t * dev_priv)
598 {
599         uint32_t agp_base;
600         uint32_t pause_addr_lo, pause_addr_hi;
601         uint32_t jump_addr_lo, jump_addr_hi;
602         volatile uint32_t *last_pause_ptr;
603         uint32_t dma_low_save1, dma_low_save2;
604
605         agp_base = dev_priv->dma_offset + (uint32_t) dev_priv->agpAddr;
606         via_align_cmd(dev_priv,  HC_HAGPBpID_JUMP, 0, &jump_addr_hi, 
607                       &jump_addr_lo, 0);
608         
609         dev_priv->dma_wrap = dev_priv->dma_low;
610
611
612         /*
613          * Wrap command buffer to the beginning.
614          */
615
616         dev_priv->dma_low = 0;
617         if (via_cmdbuf_wait(dev_priv, CMDBUF_ALIGNMENT_SIZE) != 0) {
618                 DRM_ERROR("via_cmdbuf_jump failed\n");
619         }
620
621         via_dummy_bitblt(dev_priv);
622         via_dummy_bitblt(dev_priv); 
623
624         last_pause_ptr = via_align_cmd(dev_priv,  HC_HAGPBpID_PAUSE, 0, &pause_addr_hi, 
625                                        &pause_addr_lo, 0) -1;
626         via_align_cmd(dev_priv,  HC_HAGPBpID_PAUSE, 0, &pause_addr_hi, 
627                       &pause_addr_lo, 0);
628
629         *last_pause_ptr = pause_addr_lo;
630         dma_low_save1 = dev_priv->dma_low;
631
632         /*
633          * Now, set a trap that will pause the regulator if it tries to rerun the old
634          * command buffer. (Which may happen if via_hook_segment detecs a command regulator pause
635          * and reissues the jump command over PCI, while the regulator has already taken the jump
636          * and actually paused at the current buffer end).
637          * There appears to be no other way to detect this condition, since the hw_addr_pointer
638          * does not seem to get updated immediately when a jump occurs.
639          */
640
641         last_pause_ptr = via_align_cmd(dev_priv,  HC_HAGPBpID_PAUSE, 0, &pause_addr_hi, 
642                                        &pause_addr_lo, 0) -1;
643         via_align_cmd(dev_priv,  HC_HAGPBpID_PAUSE, 0, &pause_addr_hi, 
644                       &pause_addr_lo, 0);
645         *last_pause_ptr = pause_addr_lo;
646
647         dma_low_save2 = dev_priv->dma_low;
648         dev_priv->dma_low = dma_low_save1;      
649         via_hook_segment( dev_priv, jump_addr_hi, jump_addr_lo, 0);
650         dev_priv->dma_low = dma_low_save2;
651         via_hook_segment( dev_priv, pause_addr_hi, pause_addr_lo, 0);
652 }
653
654
655 static void via_cmdbuf_rewind(drm_via_private_t * dev_priv)
656 {
657         via_cmdbuf_jump(dev_priv); 
658 }
659
660 static void via_cmdbuf_flush(drm_via_private_t * dev_priv, uint32_t cmd_type)
661 {
662         uint32_t pause_addr_lo, pause_addr_hi;
663
664         via_align_cmd(dev_priv, cmd_type, 0, &pause_addr_hi, &pause_addr_lo, 0);
665         via_hook_segment( dev_priv, pause_addr_hi, pause_addr_lo, 0);
666 }
667
668
669 static void via_cmdbuf_pause(drm_via_private_t * dev_priv)
670 {
671         via_cmdbuf_flush(dev_priv, HC_HAGPBpID_PAUSE);
672 }
673
674 static void via_cmdbuf_reset(drm_via_private_t * dev_priv)
675 {
676         via_cmdbuf_flush(dev_priv, HC_HAGPBpID_STOP);
677         via_wait_idle(dev_priv);
678 }
679
680 /*
681  * User interface to the space and lag functions.
682  */
683
684 int 
685 via_cmdbuf_size(DRM_IOCTL_ARGS)
686 {
687         DRM_DEVICE;
688         drm_via_cmdbuf_size_t d_siz;
689         int ret = 0;
690         uint32_t tmp_size, count;
691         drm_via_private_t *dev_priv;
692
693         DRM_DEBUG("via cmdbuf_size\n");
694         LOCK_TEST_WITH_RETURN( dev, filp );
695
696         dev_priv = (drm_via_private_t *) dev->dev_private;
697
698         if (dev_priv->ring.virtual_start == NULL) {
699                 DRM_ERROR("%s called without initializing AGP ring buffer.\n",
700                           __FUNCTION__);
701                 return DRM_ERR(EFAULT);
702         }
703
704         DRM_COPY_FROM_USER_IOCTL(d_siz, (drm_via_cmdbuf_size_t __user *) data,
705                                  sizeof(d_siz));
706
707
708         count = 1000000;
709         tmp_size = d_siz.size;
710         switch(d_siz.func) {
711         case VIA_CMDBUF_SPACE:
712                 while (((tmp_size = via_cmdbuf_space(dev_priv)) < d_siz.size) && count--) {
713                         if (!d_siz.wait) {
714                                 break;
715                         }
716                 }
717                 if (!count) {
718                         DRM_ERROR("VIA_CMDBUF_SPACE timed out.\n");
719                         ret = DRM_ERR(EAGAIN);
720                 }
721                 break;
722         case VIA_CMDBUF_LAG:
723                 while (((tmp_size = via_cmdbuf_lag(dev_priv)) > d_siz.size) && count--) {
724                         if (!d_siz.wait) {
725                                 break;
726                         }
727                 }
728                 if (!count) {
729                         DRM_ERROR("VIA_CMDBUF_LAG timed out.\n");
730                         ret = DRM_ERR(EAGAIN);
731                 }
732                 break;
733         default:
734                 ret = DRM_ERR(EFAULT);
735         }
736         d_siz.size = tmp_size;
737
738         DRM_COPY_TO_USER_IOCTL((drm_via_cmdbuf_size_t __user *) data, d_siz,
739                                sizeof(d_siz));
740         return ret;
741 }