drm/shared-core/mga_dma.c

/* mga_dma.c -- DMA support for mga g200/g400 -*- linux-c -*-
 * Created: Mon Dec 13 01:50:01 1999 by jhartmann@precisioninsight.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 * Authors:
 *    Rickard E. (Rik) Faith <faith@valinux.com>
 *    Jeff Hartmann <jhartmann@valinux.com>
 *    Keith Whitwell <keith@tungstengraphics.com>
 *
 * Rewritten by:
 *    Gareth Hughes <gareth@valinux.com>
 */

#include "drmP.h"
#include "drm.h"
#include "mga_drm.h"
#include "mga_drv.h"

#define MGA_DEFAULT_USEC_TIMEOUT	10000
#define MGA_FREELIST_DEBUG		0

/* ================================================================
 * Engine control
 */

int mga_do_wait_for_idle(drm_mga_private_t * dev_priv)
{
	u32 status = 0;
	int i;
	DRM_DEBUG("\n");

	for (i = 0; i < dev_priv->usec_timeout; i++) {
		status = MGA_READ(MGA_STATUS) & MGA_ENGINE_IDLE_MASK;
		if (status == MGA_ENDPRDMASTS) {
			MGA_WRITE8(MGA_CRTC_INDEX, 0);
			return 0;
		}
		DRM_UDELAY(1);
	}

#if MGA_DMA_DEBUG
	DRM_ERROR("failed!\n");
	DRM_INFO("   status=0x%08x\n", status);
#endif
	return DRM_ERR(EBUSY);
}

int mga_do_dma_idle(drm_mga_private_t * dev_priv)
{
	u32 status = 0;
	int i;
	DRM_DEBUG("\n");

	for (i = 0; i < dev_priv->usec_timeout; i++) {
		status = MGA_READ(MGA_STATUS) & MGA_DMA_IDLE_MASK;
		if (status == MGA_ENDPRDMASTS)
			return 0;
		DRM_UDELAY(1);
	}

#if MGA_DMA_DEBUG
	DRM_ERROR("failed! status=0x%08x\n", status);
#endif
	return DRM_ERR(EBUSY);
}

int mga_do_dma_reset(drm_mga_private_t * dev_priv)
{
	drm_mga_sarea_t *sarea_priv = dev_priv->sarea_priv;
	drm_mga_primary_buffer_t *primary = &dev_priv->prim;

	DRM_DEBUG("\n");

	/* The primary DMA stream should look like new right about now.
	 */
	primary->tail = 0;
	primary->space = primary->size;
	primary->last_flush = 0;

	sarea_priv->last_wrap = 0;

	/* FIXME: Reset counters, buffer ages etc...
	 */

	/* FIXME: What else do we need to reinitialize?  WARP stuff?
	 */

	return 0;
}

int mga_do_engine_reset(drm_mga_private_t * dev_priv)
{
	DRM_DEBUG("\n");

	/* Okay, so we've completely screwed up and locked the engine.
	 * How about we clean up after ourselves?
	 */
	MGA_WRITE(MGA_RST, MGA_SOFTRESET);
	DRM_UDELAY(15);		/* Wait at least 10 usecs */
	MGA_WRITE(MGA_RST, 0);

	/* Initialize the registers that get clobbered by the soft
	 * reset.  Many of the core register values survive a reset,
	 * but the drawing registers are basically all gone.
	 *
	 * 3D clients should probably die after calling this.  The X
	 * server should reset the engine state to known values.
	 */
#if 0
	MGA_WRITE(MGA_PRIMPTR,
		  virt_to_bus((void *)dev_priv->prim.status_page) |
		  MGA_PRIMPTREN0 | MGA_PRIMPTREN1);
#endif

	MGA_WRITE(MGA_ICLEAR, MGA_SOFTRAPICLR);
	MGA_WRITE(MGA_IEN, MGA_SOFTRAPIEN);

	/* The primary DMA stream should look like new right about now.
	 */
	mga_do_dma_reset(dev_priv);

	/* This bad boy will never fail.
	 */
	return 0;
}

/* ================================================================
 * Primary DMA stream
 */

void mga_do_dma_flush(drm_mga_private_t * dev_priv)
{
	drm_mga_primary_buffer_t *primary = &dev_priv->prim;
	u32 head, tail;
	u32 status = 0;
	int i;
	DMA_LOCALS;
	DRM_DEBUG("\n");

	/* We need to wait so that we can do an safe flush */
	for (i = 0; i < dev_priv->usec_timeout; i++) {
		status = MGA_READ(MGA_STATUS) & MGA_ENGINE_IDLE_MASK;
		if (status == MGA_ENDPRDMASTS)
			break;
		DRM_UDELAY(1);
	}

	if (primary->tail == primary->last_flush) {
		DRM_DEBUG("   bailing out...\n");
		return;
	}

	tail = primary->tail + dev_priv->primary->offset;

	/* We need to pad the stream between flushes, as the card
	 * actually (partially?) reads the first of these commands.
	 * See page 4-16 in the G400 manual, middle of the page or so.
	 */
	BEGIN_DMA(1);

	DMA_BLOCK(MGA_DMAPAD, 0x00000000,
		  MGA_DMAPAD, 0x00000000,
		  MGA_DMAPAD, 0x00000000, MGA_DMAPAD, 0x00000000);

	ADVANCE_DMA();

	primary->last_flush = primary->tail;

	head = MGA_READ(MGA_PRIMADDRESS);

	if (head <= tail) {
		primary->space = primary->size - primary->tail;
	} else {
		primary->space = head - tail;
	}

	DRM_DEBUG("   head = 0x%06lx\n", head - dev_priv->primary->offset);
	DRM_DEBUG("   tail = 0x%06lx\n", tail - dev_priv->primary->offset);
	DRM_DEBUG("  space = 0x%06x\n", primary->space);

	mga_flush_write_combine();
	MGA_WRITE(MGA_PRIMEND, tail | MGA_PAGPXFER);

	DRM_DEBUG("done.\n");
}

void mga_do_dma_wrap_start(drm_mga_private_t * dev_priv)
{
	drm_mga_primary_buffer_t *primary = &dev_priv->prim;
	u32 head, tail;
	DMA_LOCALS;
	DRM_DEBUG("\n");

	BEGIN_DMA_WRAP();

	DMA_BLOCK(MGA_DMAPAD, 0x00000000,
		  MGA_DMAPAD, 0x00000000,
		  MGA_DMAPAD, 0x00000000, MGA_DMAPAD, 0x00000000);

	ADVANCE_DMA();

	tail = primary->tail + dev_priv->primary->offset;

	primary->tail = 0;
	primary->last_flush = 0;
	primary->last_wrap++;

	head = MGA_READ(MGA_PRIMADDRESS);

	if (head == dev_priv->primary->offset) {
		primary->space = primary->size;
	} else {
		primary->space = head - dev_priv->primary->offset;
	}

	DRM_DEBUG("   head = 0x%06lx\n", head - dev_priv->primary->offset);
	DRM_DEBUG("   tail = 0x%06x\n", primary->tail);
	DRM_DEBUG("   wrap = %d\n", primary->last_wrap);
	DRM_DEBUG("  space = 0x%06x\n", primary->space);

	mga_flush_write_combine();
	MGA_WRITE(MGA_PRIMEND, tail | MGA_PAGPXFER);

	set_bit(0, &primary->wrapped);
	DRM_DEBUG("done.\n");
}

void mga_do_dma_wrap_end(drm_mga_private_t * dev_priv)
{
	drm_mga_primary_buffer_t *primary = &dev_priv->prim;
	drm_mga_sarea_t *sarea_priv = dev_priv->sarea_priv;
	u32 head = dev_priv->primary->offset;
	DRM_DEBUG("\n");

	sarea_priv->last_wrap++;
	DRM_DEBUG("   wrap = %d\n", sarea_priv->last_wrap);

	mga_flush_write_combine();
	MGA_WRITE(MGA_PRIMADDRESS, head | MGA_DMA_GENERAL);

	clear_bit(0, &primary->wrapped);
	DRM_DEBUG("done.\n");
}

/* ================================================================
 * Freelist management
 */

#define MGA_BUFFER_USED		~0
#define MGA_BUFFER_FREE		0

#if MGA_FREELIST_DEBUG
static void mga_freelist_print(drm_device_t * dev)
{
	drm_mga_private_t *dev_priv = dev->dev_private;
	drm_mga_freelist_t *entry;

	DRM_INFO("\n");
	DRM_INFO("current dispatch: last=0x%x done=0x%x\n",
		 dev_priv->sarea_priv->last_dispatch,
		 (unsigned int)(MGA_READ(MGA_PRIMADDRESS) -
				dev_priv->primary->offset));
	DRM_INFO("current freelist:\n");

	for (entry = dev_priv->head->next; entry; entry = entry->next) {
		DRM_INFO("   %p   idx=%2d  age=0x%x 0x%06lx\n",
			 entry, entry->buf->idx, entry->age.head,
			 entry->age.head - dev_priv->primary->offset);
	}
	DRM_INFO("\n");
}
#endif

static int mga_freelist_init(drm_device_t * dev, drm_mga_private_t * dev_priv)
{
	drm_device_dma_t *dma = dev->dma;
	drm_buf_t *buf;
	drm_mga_buf_priv_t *buf_priv;
	drm_mga_freelist_t *entry;
	int i;
	DRM_DEBUG("count=%d\n", dma->buf_count);

	dev_priv->head = drm_alloc(sizeof(drm_mga_freelist_t), DRM_MEM_DRIVER);
	if (dev_priv->head == NULL)
		return DRM_ERR(ENOMEM);

	memset(dev_priv->head, 0, sizeof(drm_mga_freelist_t));
	SET_AGE(&dev_priv->head->age, MGA_BUFFER_USED, 0);

	for (i = 0; i < dma->buf_count; i++) {
		buf = dma->buflist[i];
		buf_priv = buf->dev_private;

		entry = drm_alloc(sizeof(drm_mga_freelist_t), DRM_MEM_DRIVER);
		if (entry == NULL)
			return DRM_ERR(ENOMEM);

		memset(entry, 0, sizeof(drm_mga_freelist_t));

		entry->next = dev_priv->head->next;
		entry->prev = dev_priv->head;
		SET_AGE(&entry->age, MGA_BUFFER_FREE, 0);
		entry->buf = buf;

		if (dev_priv->head->next != NULL)
			dev_priv->head->next->prev = entry;
		if (entry->next == NULL)
			dev_priv->tail = entry;

		buf_priv->list_entry = entry;
		buf_priv->discard = 0;
		buf_priv->dispatched = 0;

		dev_priv->head->next = entry;
	}

	return 0;
}

static void mga_freelist_cleanup(drm_device_t * dev)
{
	drm_mga_private_t *dev_priv = dev->dev_private;
	drm_mga_freelist_t *entry;
	drm_mga_freelist_t *next;
	DRM_DEBUG("\n");

	entry = dev_priv->head;
	while (entry) {
		next = entry->next;
		drm_free(entry, sizeof(drm_mga_freelist_t), DRM_MEM_DRIVER);
		entry = next;
	}

	dev_priv->head = dev_priv->tail = NULL;
}

#if 0
/* FIXME: Still needed?
 */
static void mga_freelist_reset(drm_device_t * dev)
{
	drm_device_dma_t *dma = dev->dma;
	drm_buf_t *buf;
	drm_mga_buf_priv_t *buf_priv;
	int i;

	for (i = 0; i < dma->buf_count; i++) {
		buf = dma->buflist[i];
		buf_priv = buf->dev_private;
		SET_AGE(&buf_priv->list_entry->age, MGA_BUFFER_FREE, 0);
	}
}
#endif

static drm_buf_t *mga_freelist_get(drm_device_t * dev)
{
	drm_mga_private_t *dev_priv = dev->dev_private;
	drm_mga_freelist_t *next;
	drm_mga_freelist_t *prev;
	drm_mga_freelist_t *tail = dev_priv->tail;
	u32 head, wrap;
	DRM_DEBUG("\n");

	head = MGA_READ(MGA_PRIMADDRESS);
	wrap = dev_priv->sarea_priv->last_wrap;

	DRM_DEBUG("   tail=0x%06lx %d\n",
		  tail->age.head ?
		  tail->age.head - dev_priv->primary->offset : 0,
		  tail->age.wrap);
	DRM_DEBUG("   head=0x%06lx %d\n",
		  head - dev_priv->primary->offset, wrap);

	if (TEST_AGE(&tail->age, head, wrap)) {
		prev = dev_priv->tail->prev;
		next = dev_priv->tail;
		prev->next = NULL;
		next->prev = next->next = NULL;
		dev_priv->tail = prev;
		SET_AGE(&next->age, MGA_BUFFER_USED, 0);
		return next->buf;
	}

	DRM_DEBUG("returning NULL!\n");
	return NULL;
}

int mga_freelist_put(drm_device_t * dev, drm_buf_t * buf)
{
	drm_mga_private_t *dev_priv = dev->dev_private;
	drm_mga_buf_priv_t *buf_priv = buf->dev_private;
	drm_mga_freelist_t *head, *entry, *prev;

	DRM_DEBUG("age=0x%06lx wrap=%d\n",
		  buf_priv->list_entry->age.head -
		  dev_priv->primary->offset, buf_priv->list_entry->age.wrap);

	entry = buf_priv->list_entry;
	head = dev_priv->head;

	if (buf_priv->list_entry->age.head == MGA_BUFFER_USED) {
		SET_AGE(&entry->age, MGA_BUFFER_FREE, 0);
		prev = dev_priv->tail;
		prev->next = entry;
		entry->prev = prev;
		entry->next = NULL;
	} else {
		prev = head->next;
		head->next = entry;
		prev->prev = entry;
		entry->prev = head;
		entry->next = prev;
	}

	return 0;
}

/* ================================================================
 * DMA initialization, cleanup
 */

static int mga_do_init_dma(drm_device_t * dev, drm_mga_init_t * init)
{
	drm_mga_private_t *dev_priv;
	int ret;
	DRM_DEBUG("\n");

	dev_priv = drm_alloc(sizeof(drm_mga_private_t), DRM_MEM_DRIVER);
	if (!dev_priv)
		return DRM_ERR(ENOMEM);

	memset(dev_priv, 0, sizeof(drm_mga_private_t));

	dev_priv->chipset = init->chipset;

	dev_priv->usec_timeout = MGA_DEFAULT_USEC_TIMEOUT;

	if (init->sgram) {
		dev_priv->clear_cmd = MGA_DWGCTL_CLEAR | MGA_ATYPE_BLK;
	} else {
		dev_priv->clear_cmd = MGA_DWGCTL_CLEAR | MGA_ATYPE_RSTR;
	}
	dev_priv->maccess = init->maccess;

	dev_priv->fb_cpp = init->fb_cpp;
	dev_priv->front_offset = init->front_offset;
	dev_priv->front_pitch = init->front_pitch;
	dev_priv->back_offset = init->back_offset;
	dev_priv->back_pitch = init->back_pitch;

	dev_priv->depth_cpp = init->depth_cpp;
	dev_priv->depth_offset = init->depth_offset;
	dev_priv->depth_pitch = init->depth_pitch;

	/* FIXME: Need to support AGP textures...
	 */
	dev_priv->texture_offset = init->texture_offset[0];
	dev_priv->texture_size = init->texture_size[0];

	DRM_GETSAREA();

	if (!dev_priv->sarea) {
		DRM_ERROR("failed to find sarea!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(EINVAL);
	}

	dev_priv->mmio = drm_core_findmap(dev, init->mmio_offset);
	if (!dev_priv->mmio) {
		DRM_ERROR("failed to find mmio region!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(EINVAL);
	}
	dev_priv->status = drm_core_findmap(dev, init->status_offset);
	if (!dev_priv->status) {
		DRM_ERROR("failed to find status page!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(EINVAL);
	}
	dev_priv->warp = drm_core_findmap(dev, init->warp_offset);
	if (!dev_priv->warp) {
		DRM_ERROR("failed to find warp microcode region!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(EINVAL);
	}
	dev_priv->primary = drm_core_findmap(dev, init->primary_offset);
	if (!dev_priv->primary) {
		DRM_ERROR("failed to find primary dma region!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(EINVAL);
	}
	dev->agp_buffer_map = drm_core_findmap(dev, init->buffers_offset);
	if (!dev->agp_buffer_map) {
		DRM_ERROR("failed to find dma buffer region!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(EINVAL);
	}

	dev_priv->sarea_priv =
	    (drm_mga_sarea_t *) ((u8 *) dev_priv->sarea->handle +
				 init->sarea_priv_offset);

	drm_core_ioremap(dev_priv->warp, dev);
	drm_core_ioremap(dev_priv->primary, dev);
	drm_core_ioremap(dev->agp_buffer_map, dev);

	if (!dev_priv->warp->handle ||
	    !dev_priv->primary->handle || !dev->agp_buffer_map->handle) {
		DRM_ERROR("failed to ioremap agp regions!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(ENOMEM);
	}

	ret = mga_warp_install_microcode(dev_priv);
	if (ret < 0) {
		DRM_ERROR("failed to install WARP ucode!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return ret;
	}

	ret = mga_warp_init(dev_priv);
	if (ret < 0) {
		DRM_ERROR("failed to init WARP engine!\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return ret;
	}

	dev_priv->prim.status = (u32 *) dev_priv->status->handle;

	mga_do_wait_for_idle(dev_priv);

	/* Init the primary DMA registers.
	 */
	MGA_WRITE(MGA_PRIMADDRESS, dev_priv->primary->offset | MGA_DMA_GENERAL);
#if 0
	MGA_WRITE(MGA_PRIMPTR, virt_to_bus((void *)dev_priv->prim.status) | MGA_PRIMPTREN0 |	/* Soft trap, SECEND, SETUPEND */
		  MGA_PRIMPTREN1);	/* DWGSYNC */
#endif

	dev_priv->prim.start = (u8 *) dev_priv->primary->handle;
	dev_priv->prim.end = ((u8 *) dev_priv->primary->handle
			      + dev_priv->primary->size);
	dev_priv->prim.size = dev_priv->primary->size;

	dev_priv->prim.tail = 0;
	dev_priv->prim.space = dev_priv->prim.size;
	dev_priv->prim.wrapped = 0;

	dev_priv->prim.last_flush = 0;
	dev_priv->prim.last_wrap = 0;

	dev_priv->prim.high_mark = 256 * DMA_BLOCK_SIZE;

	dev_priv->prim.status[0] = dev_priv->primary->offset;
	dev_priv->prim.status[1] = 0;

	dev_priv->sarea_priv->last_wrap = 0;
	dev_priv->sarea_priv->last_frame.head = 0;
	dev_priv->sarea_priv->last_frame.wrap = 0;

	if (mga_freelist_init(dev, dev_priv) < 0) {
		DRM_ERROR("could not initialize freelist\n");
		/* Assign dev_private so we can do cleanup. */
		dev->dev_private = (void *)dev_priv;
		mga_do_cleanup_dma(dev);
		return DRM_ERR(ENOMEM);
	}

	/* Make dev_private visable to others. */
	dev->dev_private = (void *)dev_priv;
	return 0;
}

int mga_do_cleanup_dma(drm_device_t * dev)
{
	DRM_DEBUG("\n");

	/* Make sure interrupts are disabled here because the uninstall ioctl
	 * may not have been called from userspace and after dev_private
	 * is freed, it's too late.
	 */
	if (dev->irq_enabled)
		drm_irq_uninstall(dev);

	if (dev->dev_private) {
		drm_mga_private_t *dev_priv = dev->dev_private;

		if (dev_priv->warp != NULL)
			drm_core_ioremapfree(dev_priv->warp, dev);
		if (dev_priv->primary != NULL)
			drm_core_ioremapfree(dev_priv->primary, dev);
		if (dev->agp_buffer_map != NULL) {
			drm_core_ioremapfree(dev->agp_buffer_map, dev);
			dev->agp_buffer_map = NULL;
		}

		if (dev_priv->head != NULL) {
			mga_freelist_cleanup(dev);
		}

		drm_free(dev->dev_private, sizeof(drm_mga_private_t),
			 DRM_MEM_DRIVER);
		dev->dev_private = NULL;
	}

	return 0;
}

int mga_dma_init(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_mga_init_t init;

	LOCK_TEST_WITH_RETURN(dev, filp);

	DRM_COPY_FROM_USER_IOCTL(init, (drm_mga_init_t __user *) data,
				 sizeof(init));

	switch (init.func) {
	case MGA_INIT_DMA:
		return mga_do_init_dma(dev, &init);
	case MGA_CLEANUP_DMA:
		return mga_do_cleanup_dma(dev);
	}

	return DRM_ERR(EINVAL);
}

/* ================================================================
 * Primary DMA stream management
 */

int mga_dma_flush(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
	drm_lock_t lock;

	LOCK_TEST_WITH_RETURN(dev, filp);

	DRM_COPY_FROM_USER_IOCTL(lock, (drm_lock_t __user *) data,
				 sizeof(lock));

	DRM_DEBUG("%s%s%s\n",
		  (lock.flags & _DRM_LOCK_FLUSH) ? "flush, " : "",
		  (lock.flags & _DRM_LOCK_FLUSH_ALL) ? "flush all, " : "",
		  (lock.flags & _DRM_LOCK_QUIESCENT) ? "idle, " : "");

	WRAP_WAIT_WITH_RETURN(dev_priv);

	if (lock.flags & (_DRM_LOCK_FLUSH | _DRM_LOCK_FLUSH_ALL)) {
		mga_do_dma_flush(dev_priv);
	}

	if (lock.flags & _DRM_LOCK_QUIESCENT) {
#if MGA_DMA_DEBUG
		int ret = mga_do_wait_for_idle(dev_priv);
		if (ret < 0)
			DRM_INFO("%s: -EBUSY\n", __FUNCTION__);
		return ret;
#else
		return mga_do_wait_for_idle(dev_priv);
#endif
	} else {
		return 0;
	}
}

int mga_dma_reset(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;

	LOCK_TEST_WITH_RETURN(dev, filp);

	return mga_do_dma_reset(dev_priv);
}

/* ================================================================
 * DMA buffer management
 */

static int mga_dma_get_buffers(DRMFILE filp, drm_device_t * dev, drm_dma_t * d)
{
	drm_buf_t *buf;
	int i;

	for (i = d->granted_count; i < d->request_count; i++) {
		buf = mga_freelist_get(dev);
		if (!buf)
			return DRM_ERR(EAGAIN);

		buf->filp = filp;

		if (DRM_COPY_TO_USER(&d->request_indices[i],
				     &buf->idx, sizeof(buf->idx)))
			return DRM_ERR(EFAULT);
		if (DRM_COPY_TO_USER(&d->request_sizes[i],
				     &buf->total, sizeof(buf->total)))
			return DRM_ERR(EFAULT);

		d->granted_count++;
	}
	return 0;
}

int mga_dma_buffers(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_device_dma_t *dma = dev->dma;
	drm_mga_private_t *dev_priv = (drm_mga_private_t *) dev->dev_private;
	drm_dma_t __user *argp = (void __user *)data;
	drm_dma_t d;
	int ret = 0;

	LOCK_TEST_WITH_RETURN(dev, filp);

	DRM_COPY_FROM_USER_IOCTL(d, argp, sizeof(d));

	/* Please don't send us buffers.
	 */
	if (d.send_count != 0) {
		DRM_ERROR("Process %d trying to send %d buffers via drmDMA\n",
			  DRM_CURRENTPID, d.send_count);
		return DRM_ERR(EINVAL);
	}

	/* We'll send you buffers.
	 */
	if (d.request_count < 0 || d.request_count > dma->buf_count) {
		DRM_ERROR("Process %d trying to get %d buffers (of %d max)\n",
			  DRM_CURRENTPID, d.request_count, dma->buf_count);
		return DRM_ERR(EINVAL);
	}

	WRAP_TEST_WITH_RETURN(dev_priv);

	d.granted_count = 0;

	if (d.request_count) {
		ret = mga_dma_get_buffers(filp, dev, &d);
	}

	DRM_COPY_TO_USER_IOCTL(argp, d, sizeof(d));

	return ret;
}

void mga_driver_pretakedown(drm_device_t * dev)
{
	mga_do_cleanup_dma(dev);
}

int mga_driver_dma_quiescent(drm_device_t * dev)
{
	drm_mga_private_t *dev_priv = dev->dev_private;
	return mga_do_wait_for_idle(dev_priv);
}