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      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 (at) valinux.com>
      7  * \author Frank C. Earl <fearl (at) airmail.net>
      8  * \author Leif Delgass <ldelgass (at) retinalburn.net>
      9  * \author Jos Fonseca <j_r_fonseca (at) 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__ __unused 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