1 /* mach64_dma.c -- DMA support for mach64 (Rage Pro) driver -*- linux-c -*- */
2 /**
3  * \file mach64_dma.c
4  * DMA support for mach64 (Rage Pro) driver
5  *
6  * \author Gareth Hughes <gareth@valinux.com>
7  * \author Frank C. Earl <fearl@airmail.net>
8  * \author Leif Delgass <ldelgass@retinalburn.net>
9  * \author José Fonseca <j_r_fonseca@yahoo.co.uk>
10  */
11 
12 /*
13  * Copyright 2000 Gareth Hughes
14  * Copyright 2002 Frank C. Earl
15  * Copyright 2002-2003 Leif Delgass
16  * All Rights Reserved.
17  *
18  * Permission is hereby granted, free of charge, to any person obtaining a
19  * copy of this software and associated documentation files (the "Software"),
20  * to deal in the Software without restriction, including without limitation
21  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
22  * and/or sell copies of the Software, and to permit persons to whom the
23  * Software is furnished to do so, subject to the following conditions:
24  *
25  * The above copyright notice and this permission notice (including the next
26  * paragraph) shall be included in all copies or substantial portions of the
27  * Software.
28  *
29  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
30  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
31  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
32  * THE COPYRIGHT OWNER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
33  * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
34  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
35  */
36 
37 #include "drmP.h"
38 #include "drm.h"
39 #include "mach64_drm.h"
40 #include "mach64_drv.h"
41 
42 /*******************************************************************/
43 /** \name Engine, FIFO control */
44 /*@{*/
45 
46 /**
47  * Waits for free entries in the FIFO.
48  *
49  * \note Most writes to Mach64 registers are automatically routed through
50  * command FIFO which is 16 entry deep. Prior to writing to any draw engine
51  * register one has to ensure that enough FIFO entries are available by calling
52  * this function.  Failure to do so may cause the engine to lock.
53  *
54  * \param dev_priv pointer to device private data structure.
55  * \param entries number of free entries in the FIFO to wait for.
56  *
57  * \returns zero on success, or -EBUSY if the timeout (specificed by
58  * drm_mach64_private::usec_timeout) occurs.
59  */
60 int mach64_do_wait_for_fifo(drm_mach64_private_t *dev_priv, int entries)
61 {
62 	int slots = 0, i;
63 
64 	for (i = 0; i < dev_priv->usec_timeout; i++) {
65 		slots = (MACH64_READ(MACH64_FIFO_STAT) & MACH64_FIFO_SLOT_MASK);
66 		if (slots <= (0x8000 >> entries))
67 			return 0;
68 		DRM_UDELAY(1);
69 	}
70 
71 	DRM_INFO("failed! slots=%d entries=%d\n", slots, entries);
72 	return -EBUSY;
73 }
74 
75 /**
76  * Wait for the draw engine to be idle.
77  */
78 int mach64_do_wait_for_idle(drm_mach64_private_t *dev_priv)
79 {
80 	int i, ret;
81 
82 	ret = mach64_do_wait_for_fifo(dev_priv, 16);
83 	if (ret < 0)
84 		return ret;
85 
86 	for (i = 0; i < dev_priv->usec_timeout; i++) {
87 		if (!(MACH64_READ(MACH64_GUI_STAT) & MACH64_GUI_ACTIVE))
88 			return 0;
89 		DRM_UDELAY(1);
90 	}
91 
92 	DRM_INFO("failed! GUI_STAT=0x%08x\n", MACH64_READ(MACH64_GUI_STAT));
93 	mach64_dump_ring_info(dev_priv);
94 	return -EBUSY;
95 }
96 
97 /**
98  * Wait for free entries in the ring buffer.
99  *
100  * The Mach64 bus master can be configured to act as a virtual FIFO, using a
101  * circular buffer (commonly referred as "ring buffer" in other drivers) with
102  * pointers to engine commands. This allows the CPU to do other things while
103  * the graphics engine is busy, i.e., DMA mode.
104  *
105  * This function should be called before writing new entries to the ring
106  * buffer.
107  *
108  * \param dev_priv pointer to device private data structure.
109  * \param n number of free entries in the ring buffer to wait for.
110  *
111  * \returns zero on success, or -EBUSY if the timeout (specificed by
112  * drm_mach64_private_t::usec_timeout) occurs.
113  *
114  * \sa mach64_dump_ring_info()
115  */
116 int mach64_wait_ring(drm_mach64_private_t *dev_priv, int n)
117 {
118 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
119 	int i;
120 
121 	for (i = 0; i < dev_priv->usec_timeout; i++) {
122 		mach64_update_ring_snapshot(dev_priv);
123 		if (ring->space >= n) {
124 			if (i > 0)
125 				DRM_DEBUG("%d usecs\n", i);
126 			return 0;
127 		}
128 		DRM_UDELAY(1);
129 	}
130 
131 	/* FIXME: This is being ignored... */
132 	DRM_ERROR("failed!\n");
133 	mach64_dump_ring_info(dev_priv);
134 	return -EBUSY;
135 }
136 
137 /**
138  * Wait until all DMA requests have been processed...
139  *
140  * \sa mach64_wait_ring()
141  */
142 static int mach64_ring_idle(drm_mach64_private_t *dev_priv)
143 {
144 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
145 	u32 head;
146 	int i;
147 
148 	head = ring->head;
149 	i = 0;
150 	while (i < dev_priv->usec_timeout) {
151 		mach64_update_ring_snapshot(dev_priv);
152 		if (ring->head == ring->tail &&
153 		    !(MACH64_READ(MACH64_GUI_STAT) & MACH64_GUI_ACTIVE)) {
154 			if (i > 0)
155 				DRM_DEBUG("%d usecs\n", i);
156 			return 0;
157 		}
158 		if (ring->head == head) {
159 			++i;
160 		} else {
161 			head = ring->head;
162 			i = 0;
163 		}
164 		DRM_UDELAY(1);
165 	}
166 
167 	DRM_INFO("failed! GUI_STAT=0x%08x\n", MACH64_READ(MACH64_GUI_STAT));
168 	mach64_dump_ring_info(dev_priv);
169 	return -EBUSY;
170 }
171 
172 /**
173  * Reset the the ring buffer descriptors.
174  *
175  * \sa mach64_do_engine_reset()
176  */
177 static void mach64_ring_reset(drm_mach64_private_t *dev_priv)
178 {
179 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
180 
181 	mach64_do_release_used_buffers(dev_priv);
182 	ring->head_addr = ring->start_addr;
183 	ring->head = ring->tail = 0;
184 	ring->space = ring->size;
185 
186 	MACH64_WRITE(MACH64_BM_GUI_TABLE_CMD,
187 		     ring->head_addr | MACH64_CIRCULAR_BUF_SIZE_16KB);
188 
189 	dev_priv->ring_running = 0;
190 }
191 
192 /**
193  * Ensure the all the queued commands will be processed.
194  */
195 int mach64_do_dma_flush(drm_mach64_private_t *dev_priv)
196 {
197 	/* FIXME: It's not necessary to wait for idle when flushing
198 	 * we just need to ensure the ring will be completely processed
199 	 * in finite time without another ioctl
200 	 */
201 	return mach64_ring_idle(dev_priv);
202 }
203 
204 /**
205  * Stop all DMA activity.
206  */
207 int mach64_do_dma_idle(drm_mach64_private_t *dev_priv)
208 {
209 	int ret;
210 
211 	/* wait for completion */
212 	if ((ret = mach64_ring_idle(dev_priv)) < 0) {
213 		DRM_ERROR("failed BM_GUI_TABLE=0x%08x tail: %u\n",
214 			  MACH64_READ(MACH64_BM_GUI_TABLE),
215 			  dev_priv->ring.tail);
216 		return ret;
217 	}
218 
219 	mach64_ring_stop(dev_priv);
220 
221 	/* clean up after pass */
222 	mach64_do_release_used_buffers(dev_priv);
223 	return 0;
224 }
225 
226 /**
227  * Reset the engine.  This will stop the DMA if it is running.
228  */
229 int mach64_do_engine_reset(drm_mach64_private_t *dev_priv)
230 {
231 	u32 tmp;
232 
233 	DRM_DEBUG("\n");
234 
235 	/* Kill off any outstanding DMA transfers.
236 	 */
237 	tmp = MACH64_READ(MACH64_BUS_CNTL);
238 	MACH64_WRITE(MACH64_BUS_CNTL, tmp | MACH64_BUS_MASTER_DIS);
239 
240 	/* Reset the GUI engine (high to low transition).
241 	 */
242 	tmp = MACH64_READ(MACH64_GEN_TEST_CNTL);
243 	MACH64_WRITE(MACH64_GEN_TEST_CNTL, tmp & ~MACH64_GUI_ENGINE_ENABLE);
244 	/* Enable the GUI engine
245 	 */
246 	tmp = MACH64_READ(MACH64_GEN_TEST_CNTL);
247 	MACH64_WRITE(MACH64_GEN_TEST_CNTL, tmp | MACH64_GUI_ENGINE_ENABLE);
248 
249 	/* ensure engine is not locked up by clearing any FIFO or HOST errors
250 	 */
251 	tmp = MACH64_READ(MACH64_BUS_CNTL);
252 	MACH64_WRITE(MACH64_BUS_CNTL, tmp | 0x00a00000);
253 
254 	/* Once GUI engine is restored, disable bus mastering */
255 	MACH64_WRITE(MACH64_SRC_CNTL, 0);
256 
257 	/* Reset descriptor ring */
258 	mach64_ring_reset(dev_priv);
259 
260 	return 0;
261 }
262 
263 /*@}*/
264 
265 
266 /*******************************************************************/
267 /** \name Debugging output */
268 /*@{*/
269 
270 /**
271  * Dump engine registers values.
272  */
273 void mach64_dump_engine_info(drm_mach64_private_t *dev_priv)
274 {
275 	DRM_INFO("\n");
276 	if (!dev_priv->is_pci) {
277 		DRM_INFO("           AGP_BASE = 0x%08x\n",
278 			 MACH64_READ(MACH64_AGP_BASE));
279 		DRM_INFO("           AGP_CNTL = 0x%08x\n",
280 			 MACH64_READ(MACH64_AGP_CNTL));
281 	}
282 	DRM_INFO("     ALPHA_TST_CNTL = 0x%08x\n",
283 		 MACH64_READ(MACH64_ALPHA_TST_CNTL));
284 	DRM_INFO("\n");
285 	DRM_INFO("         BM_COMMAND = 0x%08x\n",
286 		 MACH64_READ(MACH64_BM_COMMAND));
287 	DRM_INFO("BM_FRAME_BUF_OFFSET = 0x%08x\n",
288 		 MACH64_READ(MACH64_BM_FRAME_BUF_OFFSET));
289 	DRM_INFO("       BM_GUI_TABLE = 0x%08x\n",
290 		 MACH64_READ(MACH64_BM_GUI_TABLE));
291 	DRM_INFO("          BM_STATUS = 0x%08x\n",
292 		 MACH64_READ(MACH64_BM_STATUS));
293 	DRM_INFO(" BM_SYSTEM_MEM_ADDR = 0x%08x\n",
294 		 MACH64_READ(MACH64_BM_SYSTEM_MEM_ADDR));
295 	DRM_INFO("    BM_SYSTEM_TABLE = 0x%08x\n",
296 		 MACH64_READ(MACH64_BM_SYSTEM_TABLE));
297 	DRM_INFO("           BUS_CNTL = 0x%08x\n",
298 		 MACH64_READ(MACH64_BUS_CNTL));
299 	DRM_INFO("\n");
300 	/* DRM_INFO( "         CLOCK_CNTL = 0x%08x\n", MACH64_READ( MACH64_CLOCK_CNTL ) ); */
301 	DRM_INFO("        CLR_CMP_CLR = 0x%08x\n",
302 		 MACH64_READ(MACH64_CLR_CMP_CLR));
303 	DRM_INFO("       CLR_CMP_CNTL = 0x%08x\n",
304 		 MACH64_READ(MACH64_CLR_CMP_CNTL));
305 	/* DRM_INFO( "        CLR_CMP_MSK = 0x%08x\n", MACH64_READ( MACH64_CLR_CMP_MSK ) ); */
306 	DRM_INFO("     CONFIG_CHIP_ID = 0x%08x\n",
307 		 MACH64_READ(MACH64_CONFIG_CHIP_ID));
308 	DRM_INFO("        CONFIG_CNTL = 0x%08x\n",
309 		 MACH64_READ(MACH64_CONFIG_CNTL));
310 	DRM_INFO("       CONFIG_STAT0 = 0x%08x\n",
311 		 MACH64_READ(MACH64_CONFIG_STAT0));
312 	DRM_INFO("       CONFIG_STAT1 = 0x%08x\n",
313 		 MACH64_READ(MACH64_CONFIG_STAT1));
314 	DRM_INFO("       CONFIG_STAT2 = 0x%08x\n",
315 		 MACH64_READ(MACH64_CONFIG_STAT2));
316 	DRM_INFO("            CRC_SIG = 0x%08x\n", MACH64_READ(MACH64_CRC_SIG));
317 	DRM_INFO("  CUSTOM_MACRO_CNTL = 0x%08x\n",
318 		 MACH64_READ(MACH64_CUSTOM_MACRO_CNTL));
319 	DRM_INFO("\n");
320 	/* DRM_INFO( "           DAC_CNTL = 0x%08x\n", MACH64_READ( MACH64_DAC_CNTL ) ); */
321 	/* DRM_INFO( "           DAC_REGS = 0x%08x\n", MACH64_READ( MACH64_DAC_REGS ) ); */
322 	DRM_INFO("        DP_BKGD_CLR = 0x%08x\n",
323 		 MACH64_READ(MACH64_DP_BKGD_CLR));
324 	DRM_INFO("        DP_FRGD_CLR = 0x%08x\n",
325 		 MACH64_READ(MACH64_DP_FRGD_CLR));
326 	DRM_INFO("             DP_MIX = 0x%08x\n", MACH64_READ(MACH64_DP_MIX));
327 	DRM_INFO("       DP_PIX_WIDTH = 0x%08x\n",
328 		 MACH64_READ(MACH64_DP_PIX_WIDTH));
329 	DRM_INFO("             DP_SRC = 0x%08x\n", MACH64_READ(MACH64_DP_SRC));
330 	DRM_INFO("      DP_WRITE_MASK = 0x%08x\n",
331 		 MACH64_READ(MACH64_DP_WRITE_MASK));
332 	DRM_INFO("         DSP_CONFIG = 0x%08x\n",
333 		 MACH64_READ(MACH64_DSP_CONFIG));
334 	DRM_INFO("         DSP_ON_OFF = 0x%08x\n",
335 		 MACH64_READ(MACH64_DSP_ON_OFF));
336 	DRM_INFO("           DST_CNTL = 0x%08x\n",
337 		 MACH64_READ(MACH64_DST_CNTL));
338 	DRM_INFO("      DST_OFF_PITCH = 0x%08x\n",
339 		 MACH64_READ(MACH64_DST_OFF_PITCH));
340 	DRM_INFO("\n");
341 	/* DRM_INFO( "       EXT_DAC_REGS = 0x%08x\n", MACH64_READ( MACH64_EXT_DAC_REGS ) ); */
342 	DRM_INFO("       EXT_MEM_CNTL = 0x%08x\n",
343 		 MACH64_READ(MACH64_EXT_MEM_CNTL));
344 	DRM_INFO("\n");
345 	DRM_INFO("          FIFO_STAT = 0x%08x\n",
346 		 MACH64_READ(MACH64_FIFO_STAT));
347 	DRM_INFO("\n");
348 	DRM_INFO("      GEN_TEST_CNTL = 0x%08x\n",
349 		 MACH64_READ(MACH64_GEN_TEST_CNTL));
350 	/* DRM_INFO( "              GP_IO = 0x%08x\n", MACH64_READ( MACH64_GP_IO ) ); */
351 	DRM_INFO("   GUI_CMDFIFO_DATA = 0x%08x\n",
352 		 MACH64_READ(MACH64_GUI_CMDFIFO_DATA));
353 	DRM_INFO("  GUI_CMDFIFO_DEBUG = 0x%08x\n",
354 		 MACH64_READ(MACH64_GUI_CMDFIFO_DEBUG));
355 	DRM_INFO("           GUI_CNTL = 0x%08x\n",
356 		 MACH64_READ(MACH64_GUI_CNTL));
357 	DRM_INFO("           GUI_STAT = 0x%08x\n",
358 		 MACH64_READ(MACH64_GUI_STAT));
359 	DRM_INFO("      GUI_TRAJ_CNTL = 0x%08x\n",
360 		 MACH64_READ(MACH64_GUI_TRAJ_CNTL));
361 	DRM_INFO("\n");
362 	DRM_INFO("          HOST_CNTL = 0x%08x\n",
363 		 MACH64_READ(MACH64_HOST_CNTL));
364 	DRM_INFO("           HW_DEBUG = 0x%08x\n",
365 		 MACH64_READ(MACH64_HW_DEBUG));
366 	DRM_INFO("\n");
367 	DRM_INFO("    MEM_ADDR_CONFIG = 0x%08x\n",
368 		 MACH64_READ(MACH64_MEM_ADDR_CONFIG));
369 	DRM_INFO("       MEM_BUF_CNTL = 0x%08x\n",
370 		 MACH64_READ(MACH64_MEM_BUF_CNTL));
371 	DRM_INFO("\n");
372 	DRM_INFO("           PAT_REG0 = 0x%08x\n",
373 		 MACH64_READ(MACH64_PAT_REG0));
374 	DRM_INFO("           PAT_REG1 = 0x%08x\n",
375 		 MACH64_READ(MACH64_PAT_REG1));
376 	DRM_INFO("\n");
377 	DRM_INFO("            SC_LEFT = 0x%08x\n", MACH64_READ(MACH64_SC_LEFT));
378 	DRM_INFO("           SC_RIGHT = 0x%08x\n",
379 		 MACH64_READ(MACH64_SC_RIGHT));
380 	DRM_INFO("             SC_TOP = 0x%08x\n", MACH64_READ(MACH64_SC_TOP));
381 	DRM_INFO("          SC_BOTTOM = 0x%08x\n",
382 		 MACH64_READ(MACH64_SC_BOTTOM));
383 	DRM_INFO("\n");
384 	DRM_INFO("      SCALE_3D_CNTL = 0x%08x\n",
385 		 MACH64_READ(MACH64_SCALE_3D_CNTL));
386 	DRM_INFO("       SCRATCH_REG0 = 0x%08x\n",
387 		 MACH64_READ(MACH64_SCRATCH_REG0));
388 	DRM_INFO("       SCRATCH_REG1 = 0x%08x\n",
389 		 MACH64_READ(MACH64_SCRATCH_REG1));
390 	DRM_INFO("         SETUP_CNTL = 0x%08x\n",
391 		 MACH64_READ(MACH64_SETUP_CNTL));
392 	DRM_INFO("           SRC_CNTL = 0x%08x\n",
393 		 MACH64_READ(MACH64_SRC_CNTL));
394 	DRM_INFO("\n");
395 	DRM_INFO("           TEX_CNTL = 0x%08x\n",
396 		 MACH64_READ(MACH64_TEX_CNTL));
397 	DRM_INFO("     TEX_SIZE_PITCH = 0x%08x\n",
398 		 MACH64_READ(MACH64_TEX_SIZE_PITCH));
399 	DRM_INFO("       TIMER_CONFIG = 0x%08x\n",
400 		 MACH64_READ(MACH64_TIMER_CONFIG));
401 	DRM_INFO("\n");
402 	DRM_INFO("             Z_CNTL = 0x%08x\n", MACH64_READ(MACH64_Z_CNTL));
403 	DRM_INFO("        Z_OFF_PITCH = 0x%08x\n",
404 		 MACH64_READ(MACH64_Z_OFF_PITCH));
405 	DRM_INFO("\n");
406 }
407 
408 #define MACH64_DUMP_CONTEXT	3
409 
410 /**
411  * Used by mach64_dump_ring_info() to dump the contents of the current buffer
412  * pointed by the ring head.
413  */
414 static void mach64_dump_buf_info(drm_mach64_private_t *dev_priv,
415 				 struct drm_buf *buf)
416 {
417 	u32 addr = GETBUFADDR(buf);
418 	u32 used = buf->used >> 2;
419 	u32 sys_addr = MACH64_READ(MACH64_BM_SYSTEM_MEM_ADDR);
420 	u32 *p = GETBUFPTR(buf);
421 	int skipped = 0;
422 
423 	DRM_INFO("buffer contents:\n");
424 
425 	while (used) {
426 		u32 reg, count;
427 
428 		reg = le32_to_cpu(*p++);
429 		if (addr <= GETBUFADDR(buf) + MACH64_DUMP_CONTEXT * 4 ||
430 		    (addr >= sys_addr - MACH64_DUMP_CONTEXT * 4 &&
431 		     addr <= sys_addr + MACH64_DUMP_CONTEXT * 4) ||
432 		    addr >=
433 		    GETBUFADDR(buf) + buf->used - MACH64_DUMP_CONTEXT * 4) {
434 			DRM_INFO("%08x:  0x%08x\n", addr, reg);
435 		}
436 		addr += 4;
437 		used--;
438 
439 		count = (reg >> 16) + 1;
440 		reg = reg & 0xffff;
441 		reg = MMSELECT(reg);
442 		while (count && used) {
443 			if (addr <= GETBUFADDR(buf) + MACH64_DUMP_CONTEXT * 4 ||
444 			    (addr >= sys_addr - MACH64_DUMP_CONTEXT * 4 &&
445 			     addr <= sys_addr + MACH64_DUMP_CONTEXT * 4) ||
446 			    addr >=
447 			    GETBUFADDR(buf) + buf->used -
448 			    MACH64_DUMP_CONTEXT * 4) {
449 				DRM_INFO("%08x:    0x%04x = 0x%08x\n", addr,
450 					 reg, le32_to_cpu(*p));
451 				skipped = 0;
452 			} else {
453 				if (!skipped) {
454 					DRM_INFO("  ...\n");
455 					skipped = 1;
456 				}
457 			}
458 			p++;
459 			addr += 4;
460 			used--;
461 
462 			reg += 4;
463 			count--;
464 		}
465 	}
466 
467 	DRM_INFO("\n");
468 }
469 
470 /**
471  * Dump the ring state and contents, including the contents of the buffer being
472  * processed by the graphics engine.
473  */
474 void mach64_dump_ring_info(drm_mach64_private_t *dev_priv)
475 {
476 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
477 	int i, skipped;
478 
479 	DRM_INFO("\n");
480 
481 	DRM_INFO("ring contents:\n");
482 	DRM_INFO("  head_addr: 0x%08x head: %u tail: %u\n\n",
483 		 ring->head_addr, ring->head, ring->tail);
484 
485 	skipped = 0;
486 	for (i = 0; i < ring->size / sizeof(u32); i += 4) {
487 		if (i <= MACH64_DUMP_CONTEXT * 4 ||
488 		    i >= ring->size / sizeof(u32) - MACH64_DUMP_CONTEXT * 4 ||
489 		    (i >= ring->tail - MACH64_DUMP_CONTEXT * 4 &&
490 		     i <= ring->tail + MACH64_DUMP_CONTEXT * 4) ||
491 		    (i >= ring->head - MACH64_DUMP_CONTEXT * 4 &&
492 		     i <= ring->head + MACH64_DUMP_CONTEXT * 4)) {
493 			DRM_INFO("  0x%08x:  0x%08x 0x%08x 0x%08x 0x%08x%s%s\n",
494 				 (u32)(ring->start_addr + i * sizeof(u32)),
495 				 le32_to_cpu(((u32 *) ring->start)[i + 0]),
496 				 le32_to_cpu(((u32 *) ring->start)[i + 1]),
497 				 le32_to_cpu(((u32 *) ring->start)[i + 2]),
498 				 le32_to_cpu(((u32 *) ring->start)[i + 3]),
499 				 i == ring->head ? " (head)" : "",
500 				 i == ring->tail ? " (tail)" : "");
501 			skipped = 0;
502 		} else {
503 			if (!skipped) {
504 				DRM_INFO("  ...\n");
505 				skipped = 1;
506 			}
507 		}
508 	}
509 
510 	DRM_INFO("\n");
511 
512 	if (ring->head < ring->size / sizeof(u32)) {
513 		struct list_head *ptr;
514 		u32 addr = le32_to_cpu(((u32 *) ring->start)[ring->head + 1]);
515 
516 		list_for_each(ptr, &dev_priv->pending) {
517 			drm_mach64_freelist_t *entry =
518 			    list_entry(ptr, drm_mach64_freelist_t, list);
519 			struct drm_buf *buf = entry->buf;
520 
521 			u32 buf_addr = GETBUFADDR(buf);
522 
523 			if (buf_addr <= addr && addr < buf_addr + buf->used)
524 				mach64_dump_buf_info(dev_priv, buf);
525 		}
526 	}
527 
528 	DRM_INFO("\n");
529 	DRM_INFO("       BM_GUI_TABLE = 0x%08x\n",
530 		 MACH64_READ(MACH64_BM_GUI_TABLE));
531 	DRM_INFO("\n");
532 	DRM_INFO("BM_FRAME_BUF_OFFSET = 0x%08x\n",
533 		 MACH64_READ(MACH64_BM_FRAME_BUF_OFFSET));
534 	DRM_INFO(" BM_SYSTEM_MEM_ADDR = 0x%08x\n",
535 		 MACH64_READ(MACH64_BM_SYSTEM_MEM_ADDR));
536 	DRM_INFO("         BM_COMMAND = 0x%08x\n",
537 		 MACH64_READ(MACH64_BM_COMMAND));
538 	DRM_INFO("\n");
539 	DRM_INFO("          BM_STATUS = 0x%08x\n",
540 		 MACH64_READ(MACH64_BM_STATUS));
541 	DRM_INFO("           BUS_CNTL = 0x%08x\n",
542 		 MACH64_READ(MACH64_BUS_CNTL));
543 	DRM_INFO("          FIFO_STAT = 0x%08x\n",
544 		 MACH64_READ(MACH64_FIFO_STAT));
545 	DRM_INFO("           GUI_STAT = 0x%08x\n",
546 		 MACH64_READ(MACH64_GUI_STAT));
547 	DRM_INFO("           SRC_CNTL = 0x%08x\n",
548 		 MACH64_READ(MACH64_SRC_CNTL));
549 }
550 
551 /*@}*/
552 
553 
554 /*******************************************************************/
555 /** \name DMA descriptor ring macros */
556 /*@{*/
557 
558 /**
559  * Add the end mark to the ring's new tail position.
560  *
561  * The bus master engine will keep processing the DMA buffers listed in the ring
562  * until it finds this mark, making it stop.
563  *
564  * \sa mach64_clear_dma_eol
565  */
566 static __inline__ void mach64_set_dma_eol(volatile u32 *addr)
567 {
568 #if defined(__i386__)
569 	int nr = 31;
570 
571 	/* Taken from include/asm-i386/bitops.h linux header */
572 	__asm__ __volatile__("lock;" "btsl %1,%0":"=m"(*addr)
573 			     :"Ir"(nr));
574 #elif defined(__powerpc__)
575 	u32 old;
576 	u32 mask = cpu_to_le32(MACH64_DMA_EOL);
577 
578 	/* Taken from the include/asm-ppc/bitops.h linux header */
579 	__asm__ __volatile__("\n\
580 1:	lwarx	%0,0,%3 \n\
581 	or	%0,%0,%2 \n\
582 	stwcx.	%0,0,%3 \n\
583 	bne-	1b":"=&r"(old), "=m"(*addr)
584 			     :"r"(mask), "r"(addr), "m"(*addr)
585 			     :"cc");
586 #elif defined(__alpha__)
587 	u32 temp;
588 	u32 mask = MACH64_DMA_EOL;
589 
590 	/* Taken from the include/asm-alpha/bitops.h linux header */
591 	__asm__ __volatile__("1:	ldl_l %0,%3\n"
592 			     "	bis %0,%2,%0\n"
593 			     "	stl_c %0,%1\n"
594 			     "	beq %0,2f\n"
595 			     ".subsection 2\n"
596 			     "2:	br 1b\n"
597 			     ".previous":"=&r"(temp), "=m"(*addr)
598 			     :"Ir"(mask), "m"(*addr));
599 #else
600 	u32 mask = cpu_to_le32(MACH64_DMA_EOL);
601 
602 	*addr |= mask;
603 #endif
604 }
605 
606 /**
607  * Remove the end mark from the ring's old tail position.
608  *
609  * It should be called after calling mach64_set_dma_eol to mark the ring's new
610  * tail position.
611  *
612  * We update the end marks while the bus master engine is in operation. Since
613  * the bus master engine may potentially be reading from the same position
614  * that we write, we must change atomically to avoid having intermediary bad
615  * data.
616  */
617 static __inline__ void mach64_clear_dma_eol(volatile u32 *addr)
618 {
619 #if defined(__i386__)
620 	int nr = 31;
621 
622 	/* Taken from include/asm-i386/bitops.h linux header */
623 	__asm__ __volatile__("lock;" "btrl %1,%0":"=m"(*addr)
624 			     :"Ir"(nr));
625 #elif defined(__powerpc__)
626 	u32 old;
627 	u32 mask = cpu_to_le32(MACH64_DMA_EOL);
628 
629 	/* Taken from the include/asm-ppc/bitops.h linux header */
630 	__asm__ __volatile__("\n\
631 1:	lwarx	%0,0,%3 \n\
632 	andc	%0,%0,%2 \n\
633 	stwcx.	%0,0,%3 \n\
634 	bne-	1b":"=&r"(old), "=m"(*addr)
635 			     :"r"(mask), "r"(addr), "m"(*addr)
636 			     :"cc");
637 #elif defined(__alpha__)
638 	u32 temp;
639 	u32 mask = ~MACH64_DMA_EOL;
640 
641 	/* Taken from the include/asm-alpha/bitops.h linux header */
642 	__asm__ __volatile__("1:	ldl_l %0,%3\n"
643 			     "	and %0,%2,%0\n"
644 			     "	stl_c %0,%1\n"
645 			     "	beq %0,2f\n"
646 			     ".subsection 2\n"
647 			     "2:	br 1b\n"
648 			     ".previous":"=&r"(temp), "=m"(*addr)
649 			     :"Ir"(mask), "m"(*addr));
650 #else
651 	u32 mask = cpu_to_le32(~MACH64_DMA_EOL);
652 
653 	*addr &= mask;
654 #endif
655 }
656 
657 #define RING_LOCALS							\
658 	int _ring_tail, _ring_write; unsigned int _ring_mask; volatile u32 *_ring
659 
660 #define RING_WRITE_OFS  _ring_write
661 
662 #define BEGIN_RING(n)							\
663 	do {								\
664 		if (MACH64_VERBOSE) {					\
665 			DRM_INFO( "BEGIN_RING( %d ) \n",		\
666 				  (n) );				\
667 		}							\
668 		if (dev_priv->ring.space <= (n) * sizeof(u32)) {	\
669 			int ret;					\
670 			if ((ret = mach64_wait_ring( dev_priv, (n) * sizeof(u32))) < 0 ) { \
671 				DRM_ERROR( "wait_ring failed, resetting engine\n"); \
672 				mach64_dump_engine_info( dev_priv );	\
673 				mach64_do_engine_reset( dev_priv );	\
674 				return ret;				\
675 			}						\
676 		}							\
677 		dev_priv->ring.space -= (n) * sizeof(u32);		\
678 		_ring = (u32 *) dev_priv->ring.start;			\
679 		_ring_tail = _ring_write = dev_priv->ring.tail;		\
680 		_ring_mask = dev_priv->ring.tail_mask;			\
681 	} while (0)
682 
683 #define OUT_RING( x )						\
684 do {								\
685 	if (MACH64_VERBOSE) {					\
686 		DRM_INFO( "   OUT_RING( 0x%08x ) at 0x%x\n",	\
687 			   (unsigned int)(x), _ring_write );	\
688 	}							\
689 	_ring[_ring_write++] = cpu_to_le32( x );		\
690 	_ring_write &= _ring_mask;				\
691 } while (0)
692 
693 #define ADVANCE_RING()							\
694 do {									\
695 	if (MACH64_VERBOSE) {						\
696 		DRM_INFO( "ADVANCE_RING() wr=0x%06x tail=0x%06x\n",	\
697 			  _ring_write, _ring_tail );			\
698 	}								\
699 	DRM_MEMORYBARRIER();						\
700 	mach64_clear_dma_eol( &_ring[(_ring_tail - 2) & _ring_mask] );	\
701 	DRM_MEMORYBARRIER();						\
702 	dev_priv->ring.tail = _ring_write;				\
703 	mach64_ring_tick( dev_priv, &(dev_priv)->ring );		\
704 } while (0)
705 
706 /**
707  * Queue a DMA buffer of registers writes into the ring buffer.
708  */
709 int mach64_add_buf_to_ring(drm_mach64_private_t *dev_priv,
710                            drm_mach64_freelist_t *entry)
711 {
712 	int bytes, pages, remainder;
713 	u32 address, page;
714 	int i;
715 	struct drm_buf *buf = entry->buf;
716 	RING_LOCALS;
717 
718 	bytes = buf->used;
719 	address = GETBUFADDR( buf );
720 	pages = (bytes + MACH64_DMA_CHUNKSIZE - 1) / MACH64_DMA_CHUNKSIZE;
721 
722 	BEGIN_RING( pages * 4 );
723 
724 	for ( i = 0 ; i < pages-1 ; i++ ) {
725 		page = address + i * MACH64_DMA_CHUNKSIZE;
726 		OUT_RING( MACH64_APERTURE_OFFSET + MACH64_BM_ADDR );
727 		OUT_RING( page );
728 		OUT_RING( MACH64_DMA_CHUNKSIZE | MACH64_DMA_HOLD_OFFSET );
729 		OUT_RING( 0 );
730 	}
731 
732 	/* generate the final descriptor for any remaining commands in this buffer */
733 	page = address + i * MACH64_DMA_CHUNKSIZE;
734 	remainder = bytes - i * MACH64_DMA_CHUNKSIZE;
735 
736 	/* Save dword offset of last descriptor for this buffer.
737 	 * This is needed to check for completion of the buffer in freelist_get
738 	 */
739 	entry->ring_ofs = RING_WRITE_OFS;
740 
741 	OUT_RING( MACH64_APERTURE_OFFSET + MACH64_BM_ADDR );
742 	OUT_RING( page );
743 	OUT_RING( remainder | MACH64_DMA_HOLD_OFFSET | MACH64_DMA_EOL );
744 	OUT_RING( 0 );
745 
746 	ADVANCE_RING();
747 
748 	return 0;
749 }
750 
751 /**
752  * Queue DMA buffer controlling host data tranfers (e.g., blit).
753  *
754  * Almost identical to mach64_add_buf_to_ring.
755  */
756 int mach64_add_hostdata_buf_to_ring(drm_mach64_private_t *dev_priv,
757                                     drm_mach64_freelist_t *entry)
758 {
759 	int bytes, pages, remainder;
760 	u32 address, page;
761 	int i;
762 	struct drm_buf *buf = entry->buf;
763 	RING_LOCALS;
764 
765 	bytes = buf->used - MACH64_HOSTDATA_BLIT_OFFSET;
766 	pages = (bytes + MACH64_DMA_CHUNKSIZE - 1) / MACH64_DMA_CHUNKSIZE;
767 	address = GETBUFADDR( buf );
768 
769 	BEGIN_RING( 4 + pages * 4 );
770 
771 	OUT_RING( MACH64_APERTURE_OFFSET + MACH64_BM_ADDR );
772 	OUT_RING( address );
773 	OUT_RING( MACH64_HOSTDATA_BLIT_OFFSET | MACH64_DMA_HOLD_OFFSET );
774 	OUT_RING( 0 );
775 	address += MACH64_HOSTDATA_BLIT_OFFSET;
776 
777 	for ( i = 0 ; i < pages-1 ; i++ ) {
778 		page = address + i * MACH64_DMA_CHUNKSIZE;
779 		OUT_RING( MACH64_APERTURE_OFFSET + MACH64_BM_HOSTDATA );
780 		OUT_RING( page );
781 		OUT_RING( MACH64_DMA_CHUNKSIZE | MACH64_DMA_HOLD_OFFSET );
782 		OUT_RING( 0 );
783 	}
784 
785 	/* generate the final descriptor for any remaining commands in this buffer */
786 	page = address + i * MACH64_DMA_CHUNKSIZE;
787 	remainder = bytes - i * MACH64_DMA_CHUNKSIZE;
788 
789 	/* Save dword offset of last descriptor for this buffer.
790 	 * This is needed to check for completion of the buffer in freelist_get
791 	 */
792 	entry->ring_ofs = RING_WRITE_OFS;
793 
794 	OUT_RING( MACH64_APERTURE_OFFSET + MACH64_BM_HOSTDATA );
795 	OUT_RING( page );
796 	OUT_RING( remainder | MACH64_DMA_HOLD_OFFSET | MACH64_DMA_EOL );
797 	OUT_RING( 0 );
798 
799 	ADVANCE_RING();
800 
801 	return 0;
802 }
803 
804 /*@}*/
805 
806 
807 /*******************************************************************/
808 /** \name DMA test and initialization */
809 /*@{*/
810 
811 /**
812  * Perform a simple DMA operation using the pattern registers to test whether
813  * DMA works.
814  *
815  * \return zero if successful.
816  *
817  * \note This function was the testbed for many experiences regarding Mach64
818  * DMA operation. It is left here since it so tricky to get DMA operating
819  * properly in some architectures and hardware.
820  */
821 static int mach64_bm_dma_test(struct drm_device * dev)
822 {
823 	drm_mach64_private_t *dev_priv = dev->dev_private;
824 	drm_dma_handle_t *cpu_addr_dmah;
825 	u32 data_addr;
826 	u32 *table, *data;
827 	u32 expected[2];
828 	u32 src_cntl, pat_reg0, pat_reg1;
829 	int i, count, failed;
830 
831 	DRM_DEBUG("\n");
832 
833 	table = (u32 *) dev_priv->ring.start;
834 
835 	/* FIXME: get a dma buffer from the freelist here */
836 	DRM_DEBUG("Allocating data memory ...\n");
837 #ifdef __FreeBSD__
838 	DRM_UNLOCK();
839 #endif
840 	cpu_addr_dmah =
841 	    drm_pci_alloc(dev, 0x1000, 0x1000, 0xfffffffful);
842 #ifdef __FreeBSD__
843 	DRM_LOCK();
844 #endif
845 	if (!cpu_addr_dmah) {
846 		DRM_INFO("data-memory allocation failed!\n");
847 		return -ENOMEM;
848 	} else {
849 		data = (u32 *) cpu_addr_dmah->vaddr;
850 		data_addr = (u32) cpu_addr_dmah->busaddr;
851 	}
852 
853 	/* Save the X server's value for SRC_CNTL and restore it
854 	 * in case our test fails.  This prevents the X server
855 	 * from disabling it's cache for this register
856 	 */
857 	src_cntl = MACH64_READ(MACH64_SRC_CNTL);
858 	pat_reg0 = MACH64_READ(MACH64_PAT_REG0);
859 	pat_reg1 = MACH64_READ(MACH64_PAT_REG1);
860 
861 	mach64_do_wait_for_fifo(dev_priv, 3);
862 
863 	MACH64_WRITE(MACH64_SRC_CNTL, 0);
864 	MACH64_WRITE(MACH64_PAT_REG0, 0x11111111);
865 	MACH64_WRITE(MACH64_PAT_REG1, 0x11111111);
866 
867 	mach64_do_wait_for_idle(dev_priv);
868 
869 	for (i = 0; i < 2; i++) {
870 		u32 reg;
871 		reg = MACH64_READ((MACH64_PAT_REG0 + i * 4));
872 		DRM_DEBUG("(Before DMA Transfer) reg %d = 0x%08x\n", i, reg);
873 		if (reg != 0x11111111) {
874 			DRM_INFO("Error initializing test registers\n");
875 			DRM_INFO("resetting engine ...\n");
876 			mach64_do_engine_reset(dev_priv);
877 			DRM_INFO("freeing data buffer memory.\n");
878 			drm_pci_free(dev, cpu_addr_dmah);
879 			return -EIO;
880 		}
881 	}
882 
883 	/* fill up a buffer with sets of 2 consecutive writes starting with PAT_REG0 */
884 	count = 0;
885 
886 	data[count++] = cpu_to_le32(DMAREG(MACH64_PAT_REG0) | (1 << 16));
887 	data[count++] = expected[0] = 0x22222222;
888 	data[count++] = expected[1] = 0xaaaaaaaa;
889 
890 	while (count < 1020) {
891 		data[count++] =
892 		    cpu_to_le32(DMAREG(MACH64_PAT_REG0) | (1 << 16));
893 		data[count++] = 0x22222222;
894 		data[count++] = 0xaaaaaaaa;
895 	}
896 	data[count++] = cpu_to_le32(DMAREG(MACH64_SRC_CNTL) | (0 << 16));
897 	data[count++] = 0;
898 
899 	DRM_DEBUG("Preparing table ...\n");
900 	table[MACH64_DMA_FRAME_BUF_OFFSET] = cpu_to_le32(MACH64_BM_ADDR +
901 							 MACH64_APERTURE_OFFSET);
902 	table[MACH64_DMA_SYS_MEM_ADDR] = cpu_to_le32(data_addr);
903 	table[MACH64_DMA_COMMAND] = cpu_to_le32(count * sizeof(u32)
904 						| MACH64_DMA_HOLD_OFFSET
905 						| MACH64_DMA_EOL);
906 	table[MACH64_DMA_RESERVED] = 0;
907 
908 	DRM_DEBUG("table[0] = 0x%08x\n", table[0]);
909 	DRM_DEBUG("table[1] = 0x%08x\n", table[1]);
910 	DRM_DEBUG("table[2] = 0x%08x\n", table[2]);
911 	DRM_DEBUG("table[3] = 0x%08x\n", table[3]);
912 
913 	for (i = 0; i < 6; i++) {
914 		DRM_DEBUG(" data[%d] = 0x%08x\n", i, data[i]);
915 	}
916 	DRM_DEBUG(" ...\n");
917 	for (i = count - 5; i < count; i++) {
918 		DRM_DEBUG(" data[%d] = 0x%08x\n", i, data[i]);
919 	}
920 
921 	DRM_MEMORYBARRIER();
922 
923 	DRM_DEBUG("waiting for idle...\n");
924 	if ((i = mach64_do_wait_for_idle(dev_priv))) {
925 		DRM_INFO("mach64_do_wait_for_idle failed (result=%d)\n", i);
926 		DRM_INFO("resetting engine ...\n");
927 		mach64_do_engine_reset(dev_priv);
928 		mach64_do_wait_for_fifo(dev_priv, 3);
929 		MACH64_WRITE(MACH64_SRC_CNTL, src_cntl);
930 		MACH64_WRITE(MACH64_PAT_REG0, pat_reg0);
931 		MACH64_WRITE(MACH64_PAT_REG1, pat_reg1);
932 		DRM_INFO("freeing data buffer memory.\n");
933 		drm_pci_free(dev, cpu_addr_dmah);
934 		return i;
935 	}
936 	DRM_DEBUG("waiting for idle...done\n");
937 
938 	DRM_DEBUG("BUS_CNTL = 0x%08x\n", MACH64_READ(MACH64_BUS_CNTL));
939 	DRM_DEBUG("SRC_CNTL = 0x%08x\n", MACH64_READ(MACH64_SRC_CNTL));
940 	DRM_DEBUG("\n");
941 	DRM_DEBUG("data bus addr = 0x%08x\n", data_addr);
942 	DRM_DEBUG("table bus addr = 0x%08x\n", dev_priv->ring.start_addr);
943 
944 	DRM_DEBUG("starting DMA transfer...\n");
945 	MACH64_WRITE(MACH64_BM_GUI_TABLE_CMD,
946 		     dev_priv->ring.start_addr | MACH64_CIRCULAR_BUF_SIZE_16KB);
947 
948 	MACH64_WRITE(MACH64_SRC_CNTL,
949 		     MACH64_SRC_BM_ENABLE | MACH64_SRC_BM_SYNC |
950 		     MACH64_SRC_BM_OP_SYSTEM_TO_REG);
951 
952 	/* Kick off the transfer */
953 	DRM_DEBUG("starting DMA transfer... done.\n");
954 	MACH64_WRITE(MACH64_DST_HEIGHT_WIDTH, 0);
955 
956 	DRM_DEBUG("waiting for idle...\n");
957 
958 	if ((i = mach64_do_wait_for_idle(dev_priv))) {
959 		/* engine locked up, dump register state and reset */
960 		DRM_INFO("mach64_do_wait_for_idle failed (result=%d)\n", i);
961 		mach64_dump_engine_info(dev_priv);
962 		DRM_INFO("resetting engine ...\n");
963 		mach64_do_engine_reset(dev_priv);
964 		mach64_do_wait_for_fifo(dev_priv, 3);
965 		MACH64_WRITE(MACH64_SRC_CNTL, src_cntl);
966 		MACH64_WRITE(MACH64_PAT_REG0, pat_reg0);
967 		MACH64_WRITE(MACH64_PAT_REG1, pat_reg1);
968 		DRM_INFO("freeing data buffer memory.\n");
969 		drm_pci_free(dev, cpu_addr_dmah);
970 		return i;
971 	}
972 
973 	DRM_DEBUG("waiting for idle...done\n");
974 
975 	/* restore SRC_CNTL */
976 	mach64_do_wait_for_fifo(dev_priv, 1);
977 	MACH64_WRITE(MACH64_SRC_CNTL, src_cntl);
978 
979 	failed = 0;
980 
981 	/* Check register values to see if the GUI master operation succeeded */
982 	for (i = 0; i < 2; i++) {
983 		u32 reg;
984 		reg = MACH64_READ((MACH64_PAT_REG0 + i * 4));
985 		DRM_DEBUG("(After DMA Transfer) reg %d = 0x%08x\n", i, reg);
986 		if (reg != expected[i]) {
987 			failed = -1;
988 		}
989 	}
990 
991 	/* restore pattern registers */
992 	mach64_do_wait_for_fifo(dev_priv, 2);
993 	MACH64_WRITE(MACH64_PAT_REG0, pat_reg0);
994 	MACH64_WRITE(MACH64_PAT_REG1, pat_reg1);
995 
996 	DRM_DEBUG("freeing data buffer memory.\n");
997 	drm_pci_free(dev, cpu_addr_dmah);
998 	DRM_DEBUG("returning ...\n");
999 
1000 	return failed;
1001 }
1002 
1003 /**
1004  * Called during the DMA initialization ioctl to initialize all the necessary
1005  * software and hardware state for DMA operation.
1006  */
1007 static int mach64_do_dma_init(struct drm_device * dev, drm_mach64_init_t * init)
1008 {
1009 	drm_mach64_private_t *dev_priv;
1010 	u32 tmp;
1011 	int i, ret;
1012 
1013 	DRM_DEBUG("\n");
1014 
1015 	dev_priv = drm_alloc(sizeof(drm_mach64_private_t), DRM_MEM_DRIVER);
1016 	if (dev_priv == NULL)
1017 		return -ENOMEM;
1018 
1019 	memset(dev_priv, 0, sizeof(drm_mach64_private_t));
1020 
1021 	dev_priv->is_pci = init->is_pci;
1022 
1023 	dev_priv->fb_bpp = init->fb_bpp;
1024 	dev_priv->front_offset = init->front_offset;
1025 	dev_priv->front_pitch = init->front_pitch;
1026 	dev_priv->back_offset = init->back_offset;
1027 	dev_priv->back_pitch = init->back_pitch;
1028 
1029 	dev_priv->depth_bpp = init->depth_bpp;
1030 	dev_priv->depth_offset = init->depth_offset;
1031 	dev_priv->depth_pitch = init->depth_pitch;
1032 
1033 	dev_priv->front_offset_pitch = (((dev_priv->front_pitch / 8) << 22) |
1034 					(dev_priv->front_offset >> 3));
1035 	dev_priv->back_offset_pitch = (((dev_priv->back_pitch / 8) << 22) |
1036 				       (dev_priv->back_offset >> 3));
1037 	dev_priv->depth_offset_pitch = (((dev_priv->depth_pitch / 8) << 22) |
1038 					(dev_priv->depth_offset >> 3));
1039 
1040 	dev_priv->usec_timeout = 1000000;
1041 
1042 	/* Set up the freelist, placeholder list and pending list */
1043 	INIT_LIST_HEAD(&dev_priv->free_list);
1044 	INIT_LIST_HEAD(&dev_priv->placeholders);
1045 	INIT_LIST_HEAD(&dev_priv->pending);
1046 
1047 	dev_priv->sarea = drm_getsarea(dev);
1048 	if (!dev_priv->sarea) {
1049 		DRM_ERROR("can not find sarea!\n");
1050 		dev->dev_private = (void *)dev_priv;
1051 		mach64_do_cleanup_dma(dev);
1052 		return -EINVAL;
1053 	}
1054 	dev_priv->fb = drm_core_findmap(dev, init->fb_offset);
1055 	if (!dev_priv->fb) {
1056 		DRM_ERROR("can not find frame buffer map!\n");
1057 		dev->dev_private = (void *)dev_priv;
1058 		mach64_do_cleanup_dma(dev);
1059 		return -EINVAL;
1060 	}
1061 	dev_priv->mmio = drm_core_findmap(dev, init->mmio_offset);
1062 	if (!dev_priv->mmio) {
1063 		DRM_ERROR("can not find mmio map!\n");
1064 		dev->dev_private = (void *)dev_priv;
1065 		mach64_do_cleanup_dma(dev);
1066 		return -EINVAL;
1067 	}
1068 
1069 	dev_priv->ring_map = drm_core_findmap(dev, init->ring_offset);
1070 	if (!dev_priv->ring_map) {
1071 		DRM_ERROR("can not find ring map!\n");
1072 		dev->dev_private = (void *)dev_priv;
1073 		mach64_do_cleanup_dma(dev);
1074 		return -EINVAL;
1075 	}
1076 
1077 	dev_priv->sarea_priv = (drm_mach64_sarea_t *)
1078 	    ((u8 *) dev_priv->sarea->handle + init->sarea_priv_offset);
1079 
1080 	if (!dev_priv->is_pci) {
1081 		drm_core_ioremap(dev_priv->ring_map, dev);
1082 		if (!dev_priv->ring_map->handle) {
1083 			DRM_ERROR("can not ioremap virtual address for"
1084 				  " descriptor ring\n");
1085 			dev->dev_private = (void *)dev_priv;
1086 			mach64_do_cleanup_dma(dev);
1087 			return -ENOMEM;
1088 		}
1089 		dev->agp_buffer_token = init->buffers_offset;
1090 		dev->agp_buffer_map =
1091 		    drm_core_findmap(dev, init->buffers_offset);
1092 		if (!dev->agp_buffer_map) {
1093 			DRM_ERROR("can not find dma buffer map!\n");
1094 			dev->dev_private = (void *)dev_priv;
1095 			mach64_do_cleanup_dma(dev);
1096 			return -EINVAL;
1097 		}
1098 		/* there might be a nicer way to do this -
1099 		   dev isn't passed all the way though the mach64 - DA */
1100 		dev_priv->dev_buffers = dev->agp_buffer_map;
1101 
1102 		drm_core_ioremap(dev->agp_buffer_map, dev);
1103 		if (!dev->agp_buffer_map->handle) {
1104 			DRM_ERROR("can not ioremap virtual address for"
1105 				  " dma buffer\n");
1106 			dev->dev_private = (void *)dev_priv;
1107 			mach64_do_cleanup_dma(dev);
1108 			return -ENOMEM;
1109 		}
1110 		dev_priv->agp_textures =
1111 		    drm_core_findmap(dev, init->agp_textures_offset);
1112 		if (!dev_priv->agp_textures) {
1113 			DRM_ERROR("can not find agp texture region!\n");
1114 			dev->dev_private = (void *)dev_priv;
1115 			mach64_do_cleanup_dma(dev);
1116 			return -EINVAL;
1117 		}
1118 	}
1119 
1120 	dev->dev_private = (void *)dev_priv;
1121 
1122 	dev_priv->driver_mode = init->dma_mode;
1123 
1124 	/* changing the FIFO size from the default causes problems with DMA */
1125 	tmp = MACH64_READ(MACH64_GUI_CNTL);
1126 	if ((tmp & MACH64_CMDFIFO_SIZE_MASK) != MACH64_CMDFIFO_SIZE_128) {
1127 		DRM_INFO("Setting FIFO size to 128 entries\n");
1128 		/* FIFO must be empty to change the FIFO depth */
1129 		if ((ret = mach64_do_wait_for_idle(dev_priv))) {
1130 			DRM_ERROR
1131 			    ("wait for idle failed before changing FIFO depth!\n");
1132 			mach64_do_cleanup_dma(dev);
1133 			return ret;
1134 		}
1135 		MACH64_WRITE(MACH64_GUI_CNTL, ((tmp & ~MACH64_CMDFIFO_SIZE_MASK)
1136 					       | MACH64_CMDFIFO_SIZE_128));
1137 		/* need to read GUI_STAT for proper sync according to docs */
1138 		if ((ret = mach64_do_wait_for_idle(dev_priv))) {
1139 			DRM_ERROR
1140 			    ("wait for idle failed when changing FIFO depth!\n");
1141 			mach64_do_cleanup_dma(dev);
1142 			return ret;
1143 		}
1144 	}
1145 
1146 	dev_priv->ring.size = 0x4000;	/* 16KB */
1147 	dev_priv->ring.start = dev_priv->ring_map->handle;
1148 	dev_priv->ring.start_addr = (u32) dev_priv->ring_map->offset;
1149 
1150 	memset(dev_priv->ring.start, 0, dev_priv->ring.size);
1151 	DRM_INFO("descriptor ring: cpu addr %p, bus addr: 0x%08x\n",
1152 		 dev_priv->ring.start, dev_priv->ring.start_addr);
1153 
1154 	ret = 0;
1155 	if (dev_priv->driver_mode != MACH64_MODE_MMIO) {
1156 
1157 		/* enable block 1 registers and bus mastering */
1158 		MACH64_WRITE(MACH64_BUS_CNTL, ((MACH64_READ(MACH64_BUS_CNTL)
1159 						| MACH64_BUS_EXT_REG_EN)
1160 					       & ~MACH64_BUS_MASTER_DIS));
1161 
1162 		/* try a DMA GUI-mastering pass and fall back to MMIO if it fails */
1163 		DRM_DEBUG("Starting DMA test...\n");
1164 		if ((ret = mach64_bm_dma_test(dev))) {
1165 			dev_priv->driver_mode = MACH64_MODE_MMIO;
1166 		}
1167 	}
1168 
1169 	switch (dev_priv->driver_mode) {
1170 	case MACH64_MODE_MMIO:
1171 		MACH64_WRITE(MACH64_BUS_CNTL, (MACH64_READ(MACH64_BUS_CNTL)
1172 					       | MACH64_BUS_EXT_REG_EN
1173 					       | MACH64_BUS_MASTER_DIS));
1174 		if (init->dma_mode == MACH64_MODE_MMIO)
1175 			DRM_INFO("Forcing pseudo-DMA mode\n");
1176 		else
1177 			DRM_INFO
1178 			    ("DMA test failed (ret=%d), using pseudo-DMA mode\n",
1179 			     ret);
1180 		break;
1181 	case MACH64_MODE_DMA_SYNC:
1182 		DRM_INFO("DMA test succeeded, using synchronous DMA mode\n");
1183 		break;
1184 	case MACH64_MODE_DMA_ASYNC:
1185 	default:
1186 		DRM_INFO("DMA test succeeded, using asynchronous DMA mode\n");
1187 	}
1188 
1189 	dev_priv->ring_running = 0;
1190 
1191 	/* setup offsets for physical address of table start and end */
1192 	dev_priv->ring.head_addr = dev_priv->ring.start_addr;
1193 	dev_priv->ring.head = dev_priv->ring.tail = 0;
1194 	dev_priv->ring.tail_mask = (dev_priv->ring.size / sizeof(u32)) - 1;
1195 	dev_priv->ring.space = dev_priv->ring.size;
1196 
1197 	/* setup physical address and size of descriptor table */
1198 	mach64_do_wait_for_fifo(dev_priv, 1);
1199 	MACH64_WRITE(MACH64_BM_GUI_TABLE_CMD,
1200 		     (dev_priv->ring.
1201 		      head_addr | MACH64_CIRCULAR_BUF_SIZE_16KB));
1202 
1203 	/* init frame counter */
1204 	dev_priv->sarea_priv->frames_queued = 0;
1205 	for (i = 0; i < MACH64_MAX_QUEUED_FRAMES; i++) {
1206 		dev_priv->frame_ofs[i] = ~0;	/* All ones indicates placeholder */
1207 	}
1208 
1209 	/* Allocate the DMA buffer freelist */
1210 	if ((ret = mach64_init_freelist(dev))) {
1211 		DRM_ERROR("Freelist allocation failed\n");
1212 		mach64_do_cleanup_dma(dev);
1213 		return ret;
1214 	}
1215 
1216 	return 0;
1217 }
1218 
1219 /*******************************************************************/
1220 /** MMIO Pseudo-DMA (intended primarily for debugging, not performance)
1221  */
1222 
1223 int mach64_do_dispatch_pseudo_dma(drm_mach64_private_t *dev_priv)
1224 {
1225 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
1226 	volatile u32 *ring_read;
1227 	struct list_head *ptr;
1228 	drm_mach64_freelist_t *entry;
1229 	struct drm_buf *buf = NULL;
1230 	u32 *buf_ptr;
1231 	u32 used, reg, target;
1232 	int fifo, count, found, ret, no_idle_wait;
1233 
1234 	fifo = count = reg = no_idle_wait = 0;
1235 	target = MACH64_BM_ADDR;
1236 
1237 	if ((ret = mach64_do_wait_for_idle(dev_priv)) < 0) {
1238 		DRM_INFO("idle failed before pseudo-dma dispatch, resetting engine\n");
1239 		mach64_dump_engine_info(dev_priv);
1240 		mach64_do_engine_reset(dev_priv);
1241 		return ret;
1242 	}
1243 
1244 	ring_read = (u32 *) ring->start;
1245 
1246 	while (ring->tail != ring->head) {
1247 		u32 buf_addr, new_target, offset;
1248 		u32 bytes, remaining, head, eol;
1249 
1250 		head = ring->head;
1251 
1252 		new_target =
1253 		    le32_to_cpu(ring_read[head++]) - MACH64_APERTURE_OFFSET;
1254 		buf_addr = le32_to_cpu(ring_read[head++]);
1255 		eol = le32_to_cpu(ring_read[head]) & MACH64_DMA_EOL;
1256 		bytes = le32_to_cpu(ring_read[head++])
1257 		    & ~(MACH64_DMA_HOLD_OFFSET | MACH64_DMA_EOL);
1258 		head++;
1259 		head &= ring->tail_mask;
1260 
1261 		/* can't wait for idle between a blit setup descriptor
1262 		 * and a HOSTDATA descriptor or the engine will lock
1263 		 */
1264 		if (new_target == MACH64_BM_HOSTDATA
1265 		    && target == MACH64_BM_ADDR)
1266 			no_idle_wait = 1;
1267 
1268 		target = new_target;
1269 
1270 		found = 0;
1271 		offset = 0;
1272 		list_for_each(ptr, &dev_priv->pending) {
1273 			entry = list_entry(ptr, drm_mach64_freelist_t, list);
1274 			buf = entry->buf;
1275 			offset = buf_addr - GETBUFADDR(buf);
1276 			if (offset < MACH64_BUFFER_SIZE) {
1277 				found = 1;
1278 				break;
1279 			}
1280 		}
1281 
1282 		if (!found || buf == NULL) {
1283 			DRM_ERROR
1284 			    ("Couldn't find pending buffer: head: %u tail: %u buf_addr: 0x%08x %s\n",
1285 			     head, ring->tail, buf_addr, (eol ? "eol" : ""));
1286 			mach64_dump_ring_info(dev_priv);
1287 			mach64_do_engine_reset(dev_priv);
1288 			return -EINVAL;
1289 		}
1290 
1291 		/* Hand feed the buffer to the card via MMIO, waiting for the fifo
1292 		 * every 16 writes
1293 		 */
1294 		DRM_DEBUG("target: (0x%08x) %s\n", target,
1295 			  (target ==
1296 			   MACH64_BM_HOSTDATA ? "BM_HOSTDATA" : "BM_ADDR"));
1297 		DRM_DEBUG("offset: %u bytes: %u used: %u\n", offset, bytes,
1298 			  buf->used);
1299 
1300 		remaining = (buf->used - offset) >> 2;	/* dwords remaining in buffer */
1301 		used = bytes >> 2;	/* dwords in buffer for this descriptor */
1302 		buf_ptr = (u32 *) ((char *)GETBUFPTR(buf) + offset);
1303 
1304 		while (used) {
1305 
1306 			if (count == 0) {
1307 				if (target == MACH64_BM_HOSTDATA) {
1308 					reg = DMAREG(MACH64_HOST_DATA0);
1309 					count =
1310 					    (remaining > 16) ? 16 : remaining;
1311 					fifo = 0;
1312 				} else {
1313 					reg = le32_to_cpu(*buf_ptr++);
1314 					used--;
1315 					count = (reg >> 16) + 1;
1316 				}
1317 
1318 				reg = reg & 0xffff;
1319 				reg = MMSELECT(reg);
1320 			}
1321 			while (count && used) {
1322 				if (!fifo) {
1323 					if (no_idle_wait) {
1324 						if ((ret =
1325 						     mach64_do_wait_for_fifo
1326 						     (dev_priv, 16)) < 0) {
1327 							no_idle_wait = 0;
1328 							return ret;
1329 						}
1330 					} else {
1331 						if ((ret =
1332 						     mach64_do_wait_for_idle
1333 						     (dev_priv)) < 0) {
1334 							return ret;
1335 						}
1336 					}
1337 					fifo = 16;
1338 				}
1339 				--fifo;
1340 				MACH64_WRITE(reg, le32_to_cpu(*buf_ptr++));
1341 				used--;
1342 				remaining--;
1343 
1344 				reg += 4;
1345 				count--;
1346 			}
1347 		}
1348 		ring->head = head;
1349 		ring->head_addr = ring->start_addr + (ring->head * sizeof(u32));
1350 		ring->space += (4 * sizeof(u32));
1351 	}
1352 
1353 	if ((ret = mach64_do_wait_for_idle(dev_priv)) < 0) {
1354 		return ret;
1355 	}
1356 	MACH64_WRITE(MACH64_BM_GUI_TABLE_CMD,
1357 		     ring->head_addr | MACH64_CIRCULAR_BUF_SIZE_16KB);
1358 
1359 	DRM_DEBUG("completed\n");
1360 	return 0;
1361 }
1362 
1363 /*@}*/
1364 
1365 
1366 /*******************************************************************/
1367 /** \name DMA cleanup */
1368 /*@{*/
1369 
1370 int mach64_do_cleanup_dma(struct drm_device * dev)
1371 {
1372 	DRM_DEBUG("\n");
1373 
1374 	/* Make sure interrupts are disabled here because the uninstall ioctl
1375 	 * may not have been called from userspace and after dev_private
1376 	 * is freed, it's too late.
1377 	 */
1378 	if (dev->irq)
1379 		drm_irq_uninstall(dev);
1380 
1381 	if (dev->dev_private) {
1382 		drm_mach64_private_t *dev_priv = dev->dev_private;
1383 
1384 		if (!dev_priv->is_pci) {
1385 			if (dev_priv->ring_map)
1386 				drm_core_ioremapfree(dev_priv->ring_map, dev);
1387 
1388 			if (dev->agp_buffer_map) {
1389 				drm_core_ioremapfree(dev->agp_buffer_map, dev);
1390 				dev->agp_buffer_map = NULL;
1391 			}
1392 		}
1393 
1394 		mach64_destroy_freelist(dev);
1395 
1396 		drm_free(dev_priv, sizeof(drm_mach64_private_t),
1397 			 DRM_MEM_DRIVER);
1398 		dev->dev_private = NULL;
1399 	}
1400 
1401 	return 0;
1402 }
1403 
1404 /*@}*/
1405 
1406 
1407 /*******************************************************************/
1408 /** \name IOCTL handlers */
1409 /*@{*/
1410 
1411 int mach64_dma_init(struct drm_device *dev, void *data,
1412 		    struct drm_file *file_priv)
1413 {
1414 	drm_mach64_init_t *init = data;
1415 
1416 	DRM_DEBUG("\n");
1417 
1418 	LOCK_TEST_WITH_RETURN(dev, file_priv);
1419 
1420 	switch (init->func) {
1421 	case DRM_MACH64_INIT_DMA:
1422 		return mach64_do_dma_init(dev, init);
1423 	case DRM_MACH64_CLEANUP_DMA:
1424 		return mach64_do_cleanup_dma(dev);
1425 	}
1426 
1427 	return -EINVAL;
1428 }
1429 
1430 int mach64_dma_idle(struct drm_device *dev, void *data,
1431 		    struct drm_file *file_priv)
1432 {
1433 	drm_mach64_private_t *dev_priv = dev->dev_private;
1434 
1435 	DRM_DEBUG("\n");
1436 
1437 	LOCK_TEST_WITH_RETURN(dev, file_priv);
1438 
1439 	return mach64_do_dma_idle(dev_priv);
1440 }
1441 
1442 int mach64_dma_flush(struct drm_device *dev, void *data,
1443 		     struct drm_file *file_priv)
1444 {
1445 	drm_mach64_private_t *dev_priv = dev->dev_private;
1446 
1447 	DRM_DEBUG("\n");
1448 
1449 	LOCK_TEST_WITH_RETURN(dev, file_priv);
1450 
1451 	return mach64_do_dma_flush(dev_priv);
1452 }
1453 
1454 int mach64_engine_reset(struct drm_device *dev, void *data,
1455 			struct drm_file *file_priv)
1456 {
1457 	drm_mach64_private_t *dev_priv = dev->dev_private;
1458 
1459 	DRM_DEBUG("\n");
1460 
1461 	LOCK_TEST_WITH_RETURN(dev, file_priv);
1462 
1463 	return mach64_do_engine_reset(dev_priv);
1464 }
1465 
1466 /*@}*/
1467 
1468 
1469 /*******************************************************************/
1470 /** \name Freelist management */
1471 /*@{*/
1472 
1473 int mach64_init_freelist(struct drm_device * dev)
1474 {
1475 	struct drm_device_dma *dma = dev->dma;
1476 	drm_mach64_private_t *dev_priv = dev->dev_private;
1477 	drm_mach64_freelist_t *entry;
1478 	struct list_head *ptr;
1479 	int i;
1480 
1481 	DRM_DEBUG("adding %d buffers to freelist\n", dma->buf_count);
1482 
1483 	for (i = 0; i < dma->buf_count; i++) {
1484 		if ((entry =
1485 		     (drm_mach64_freelist_t *)
1486 		     drm_alloc(sizeof(drm_mach64_freelist_t),
1487 			       DRM_MEM_BUFLISTS)) == NULL)
1488 			return -ENOMEM;
1489 		memset(entry, 0, sizeof(drm_mach64_freelist_t));
1490 		entry->buf = dma->buflist[i];
1491 		ptr = &entry->list;
1492 		list_add_tail(ptr, &dev_priv->free_list);
1493 	}
1494 
1495 	return 0;
1496 }
1497 
1498 void mach64_destroy_freelist(struct drm_device * dev)
1499 {
1500 	drm_mach64_private_t *dev_priv = dev->dev_private;
1501 	drm_mach64_freelist_t *entry;
1502 	struct list_head *ptr;
1503 	struct list_head *tmp;
1504 
1505 	DRM_DEBUG("\n");
1506 
1507 	list_for_each_safe(ptr, tmp, &dev_priv->pending) {
1508 		list_del(ptr);
1509 		entry = list_entry(ptr, drm_mach64_freelist_t, list);
1510 		drm_free(entry, sizeof(*entry), DRM_MEM_BUFLISTS);
1511 	}
1512 	list_for_each_safe(ptr, tmp, &dev_priv->placeholders) {
1513 		list_del(ptr);
1514 		entry = list_entry(ptr, drm_mach64_freelist_t, list);
1515 		drm_free(entry, sizeof(*entry), DRM_MEM_BUFLISTS);
1516 	}
1517 
1518 	list_for_each_safe(ptr, tmp, &dev_priv->free_list) {
1519 		list_del(ptr);
1520 		entry = list_entry(ptr, drm_mach64_freelist_t, list);
1521 		drm_free(entry, sizeof(*entry), DRM_MEM_BUFLISTS);
1522 	}
1523 }
1524 
1525 /* IMPORTANT: This function should only be called when the engine is idle or locked up,
1526  * as it assumes all buffers in the pending list have been completed by the hardware.
1527  */
1528 int mach64_do_release_used_buffers(drm_mach64_private_t *dev_priv)
1529 {
1530 	struct list_head *ptr;
1531 	struct list_head *tmp;
1532 	drm_mach64_freelist_t *entry;
1533 	int i;
1534 
1535 	if (list_empty(&dev_priv->pending))
1536 		return 0;
1537 
1538 	/* Iterate the pending list and move all buffers into the freelist... */
1539 	i = 0;
1540 	list_for_each_safe(ptr, tmp, &dev_priv->pending) {
1541 		entry = list_entry(ptr, drm_mach64_freelist_t, list);
1542 		if (entry->discard) {
1543 			entry->buf->pending = 0;
1544 			list_del(ptr);
1545 			list_add_tail(ptr, &dev_priv->free_list);
1546 			i++;
1547 		}
1548 	}
1549 
1550 	DRM_DEBUG("released %d buffers from pending list\n", i);
1551 
1552 	return 0;
1553 }
1554 
1555 static int mach64_do_reclaim_completed(drm_mach64_private_t *dev_priv)
1556 {
1557 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
1558 	struct list_head *ptr;
1559 	struct list_head *tmp;
1560 	drm_mach64_freelist_t *entry;
1561 	u32 head, tail, ofs;
1562 
1563 	mach64_ring_tick(dev_priv, ring);
1564 	head = ring->head;
1565 	tail = ring->tail;
1566 
1567 	if (head == tail) {
1568 #if MACH64_EXTRA_CHECKING
1569 		if (MACH64_READ(MACH64_GUI_STAT) & MACH64_GUI_ACTIVE) {
1570 			DRM_ERROR("Empty ring with non-idle engine!\n");
1571 			mach64_dump_ring_info(dev_priv);
1572 			return -1;
1573 		}
1574 #endif
1575 		/* last pass is complete, so release everything */
1576 		mach64_do_release_used_buffers(dev_priv);
1577 		DRM_DEBUG("idle engine, freed all buffers.\n");
1578 		if (list_empty(&dev_priv->free_list)) {
1579 			DRM_ERROR("Freelist empty with idle engine\n");
1580 			return -1;
1581 		}
1582 		return 0;
1583 	}
1584 	/* Look for a completed buffer and bail out of the loop
1585 	 * as soon as we find one -- don't waste time trying
1586 	 * to free extra bufs here, leave that to do_release_used_buffers
1587 	 */
1588 	list_for_each_safe(ptr, tmp, &dev_priv->pending) {
1589 		entry = list_entry(ptr, drm_mach64_freelist_t, list);
1590 		ofs = entry->ring_ofs;
1591 		if (entry->discard &&
1592 		    ((head < tail && (ofs < head || ofs >= tail)) ||
1593 		     (head > tail && (ofs < head && ofs >= tail)))) {
1594 #if MACH64_EXTRA_CHECKING
1595 			int i;
1596 
1597 			for (i = head; i != tail; i = (i + 4) & ring->tail_mask)
1598 			{
1599 				u32 o1 = le32_to_cpu(((u32 *) ring->
1600 						 start)[i + 1]);
1601 				u32 o2 = GETBUFADDR(entry->buf);
1602 
1603 				if (o1 == o2) {
1604 					DRM_ERROR
1605 					    ("Attempting to free used buffer: "
1606 					     "i=%d  buf=0x%08x\n",
1607 					     i, o1);
1608 					mach64_dump_ring_info(dev_priv);
1609 					return -1;
1610 				}
1611 			}
1612 #endif
1613 			/* found a processed buffer */
1614 			entry->buf->pending = 0;
1615 			list_del(ptr);
1616 			list_add_tail(ptr, &dev_priv->free_list);
1617 			DRM_DEBUG
1618 			    ("freed processed buffer (head=%d tail=%d "
1619 			     "buf ring ofs=%d).\n",
1620 			     head, tail, ofs);
1621 			return 0;
1622 		}
1623 	}
1624 
1625 	return 1;
1626 }
1627 
1628 struct drm_buf *mach64_freelist_get(drm_mach64_private_t *dev_priv)
1629 {
1630 	drm_mach64_descriptor_ring_t *ring = &dev_priv->ring;
1631 	drm_mach64_freelist_t *entry;
1632 	struct list_head *ptr;
1633 	int t;
1634 
1635 	if (list_empty(&dev_priv->free_list)) {
1636 		if (list_empty(&dev_priv->pending)) {
1637 			DRM_ERROR
1638 			    ("Couldn't get buffer - pending and free lists empty\n");
1639 			t = 0;
1640 			list_for_each(ptr, &dev_priv->placeholders) {
1641 				t++;
1642 			}
1643 			DRM_INFO("Placeholders: %d\n", t);
1644 			return NULL;
1645 		}
1646 
1647 		for (t = 0; t < dev_priv->usec_timeout; t++) {
1648 			int ret;
1649 
1650 			ret = mach64_do_reclaim_completed(dev_priv);
1651 			if (ret == 0)
1652 				goto _freelist_entry_found;
1653 			if (ret < 0)
1654 				return NULL;
1655 
1656 			DRM_UDELAY(1);
1657 		}
1658 		mach64_dump_ring_info(dev_priv);
1659 		DRM_ERROR
1660 		    ("timeout waiting for buffers: ring head_addr: 0x%08x head: %d tail: %d\n",
1661 		     ring->head_addr, ring->head, ring->tail);
1662 		return NULL;
1663 	}
1664 
1665       _freelist_entry_found:
1666 	ptr = dev_priv->free_list.next;
1667 	list_del(ptr);
1668 	entry = list_entry(ptr, drm_mach64_freelist_t, list);
1669 	entry->buf->used = 0;
1670 	list_add_tail(ptr, &dev_priv->placeholders);
1671 	return entry->buf;
1672 }
1673 
1674 int mach64_freelist_put(drm_mach64_private_t *dev_priv, struct drm_buf *copy_buf)
1675 {
1676 	struct list_head *ptr;
1677 	drm_mach64_freelist_t *entry;
1678 
1679 #if MACH64_EXTRA_CHECKING
1680 	list_for_each(ptr, &dev_priv->pending) {
1681 		entry = list_entry(ptr, drm_mach64_freelist_t, list);
1682 		if (copy_buf == entry->buf) {
1683 			DRM_ERROR("Trying to release a pending buf\n");
1684 			return -EFAULT;
1685 		}
1686 	}
1687 #endif
1688 	ptr = dev_priv->placeholders.next;
1689 	entry = list_entry(ptr, drm_mach64_freelist_t, list);
1690 	copy_buf->pending = 0;
1691 	copy_buf->used = 0;
1692 	entry->buf = copy_buf;
1693 	entry->discard = 1;
1694 	list_del(ptr);
1695 	list_add_tail(ptr, &dev_priv->free_list);
1696 
1697 	return 0;
1698 }
1699 
1700 /*@}*/
1701 
1702 
1703 /*******************************************************************/
1704 /** \name DMA buffer request and submission IOCTL handler */
1705 /*@{*/
1706 
1707 static int mach64_dma_get_buffers(struct drm_device *dev,
1708 				  struct drm_file *file_priv,
1709 				  struct drm_dma * d)
1710 {
1711 	int i;
1712 	struct drm_buf *buf;
1713 	drm_mach64_private_t *dev_priv = dev->dev_private;
1714 
1715 	for (i = d->granted_count; i < d->request_count; i++) {
1716 		buf = mach64_freelist_get(dev_priv);
1717 #if MACH64_EXTRA_CHECKING
1718 		if (!buf)
1719 			return -EFAULT;
1720 #else
1721 		if (!buf)
1722 			return -EAGAIN;
1723 #endif
1724 
1725 		buf->file_priv = file_priv;
1726 
1727 		if (DRM_COPY_TO_USER(&d->request_indices[i], &buf->idx,
1728 				     sizeof(buf->idx)))
1729 			return -EFAULT;
1730 		if (DRM_COPY_TO_USER(&d->request_sizes[i], &buf->total,
1731 				     sizeof(buf->total)))
1732 			return -EFAULT;
1733 
1734 		d->granted_count++;
1735 	}
1736 	return 0;
1737 }
1738 
1739 int mach64_dma_buffers(struct drm_device *dev, void *data,
1740 		       struct drm_file *file_priv)
1741 {
1742 	struct drm_device_dma *dma = dev->dma;
1743 	struct drm_dma *d = data;
1744 	int ret = 0;
1745 
1746 	LOCK_TEST_WITH_RETURN(dev, file_priv);
1747 
1748 	/* Please don't send us buffers.
1749 	 */
1750 	if (d->send_count != 0) {
1751 		DRM_ERROR("Process %d trying to send %d buffers via drmDMA\n",
1752 			  DRM_CURRENTPID, d->send_count);
1753 		return -EINVAL;
1754 	}
1755 
1756 	/* We'll send you buffers.
1757 	 */
1758 	if (d->request_count < 0 || d->request_count > dma->buf_count) {
1759 		DRM_ERROR("Process %d trying to get %d buffers (of %d max)\n",
1760 			  DRM_CURRENTPID, d->request_count, dma->buf_count);
1761 		ret = -EINVAL;
1762 	}
1763 
1764 	d->granted_count = 0;
1765 
1766 	if (d->request_count) {
1767 		ret = mach64_dma_get_buffers(dev, file_priv, d);
1768 	}
1769 
1770 	return ret;
1771 }
1772 
1773 void mach64_driver_lastclose(struct drm_device * dev)
1774 {
1775 	mach64_do_cleanup_dma(dev);
1776 }
1777 
1778 /*@}*/
1779