/** * \file drm_context.c * IOCTLs for generic contexts * * \author Rickard E. (Rik) Faith * \author Gareth Hughes */ /* * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com * * Copyright 1999, 2000 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 * VA LINUX SYSTEMS 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. */ /* * ChangeLog: * 2001-11-16 Torsten Duwe * added context constructor/destructor hooks, * needed by SiS driver's memory management. */ #include "drmP.h" /******************************************************************/ /** \name Context bitmap support */ /*@{*/ /** * Free a handle from the context bitmap. * * \param dev DRM device. * \param ctx_handle context handle. * * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry * in drm_device::context_sareas, while holding the drm_device::struct_mutex * lock. */ void drm_ctxbitmap_free(drm_device_t * dev, int ctx_handle) { if (ctx_handle < 0) goto failed; if (!dev->ctx_bitmap) goto failed; if (ctx_handle < DRM_MAX_CTXBITMAP) { mutex_lock(&dev->struct_mutex); clear_bit(ctx_handle, dev->ctx_bitmap); dev->context_sareas[ctx_handle] = NULL; mutex_unlock(&dev->struct_mutex); return; } failed: DRM_ERROR("Attempt to free invalid context handle: %d\n", ctx_handle); return; } /** * Context bitmap allocation. * * \param dev DRM device. * \return (non-negative) context handle on success or a negative number on failure. * * Find the first zero bit in drm_device::ctx_bitmap and (re)allocates * drm_device::context_sareas to accommodate the new entry while holding the * drm_device::struct_mutex lock. */ static int drm_ctxbitmap_next(drm_device_t * dev) { int bit; if (!dev->ctx_bitmap) return -1; mutex_lock(&dev->struct_mutex); bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP); if (bit < DRM_MAX_CTXBITMAP) { set_bit(bit, dev->ctx_bitmap); DRM_DEBUG("drm_ctxbitmap_next bit : %d\n", bit); if ((bit + 1) > dev->max_context) { dev->max_context = (bit + 1); if (dev->context_sareas) { drm_map_t **ctx_sareas; ctx_sareas = drm_realloc(dev->context_sareas, (dev->max_context - 1) * sizeof(*dev-> context_sareas), dev->max_context * sizeof(*dev-> context_sareas), DRM_MEM_MAPS); if (!ctx_sareas) { clear_bit(bit, dev->ctx_bitmap); mutex_unlock(&dev->struct_mutex); return -1; } dev->context_sareas = ctx_sareas; dev->context_sareas[bit] = NULL; } else { /* max_context == 1 at this point */ dev->context_sareas = drm_alloc(dev->max_context * sizeof(*dev->context_sareas), DRM_MEM_MAPS); if (!dev->context_sareas) { clear_bit(bit, dev->ctx_bitmap); mutex_unlock(&dev->struct_mutex); return -1; } dev->context_sareas[bit] = NULL; } } mutex_unlock(&dev->struct_mutex); return bit; } mutex_unlock(&dev->struct_mutex); return -1; } /** * Context bitmap initialization. * * \param dev DRM device. * * Allocates and initialize drm_device::ctx_bitmap and drm_device::context_sareas, while holding * the drm_device::struct_mutex lock. */ int drm_ctxbitmap_init(drm_device_t * dev) { int i; int temp; mutex_lock(&dev->struct_mutex); dev->ctx_bitmap = (unsigned long *)drm_alloc(PAGE_SIZE, DRM_MEM_CTXBITMAP); if (dev->ctx_bitmap == NULL) { mutex_unlock(&dev->struct_mutex); return -ENOMEM; } memset((void *)dev->ctx_bitmap, 0, PAGE_SIZE); dev->context_sareas = NULL; dev->max_context = -1; mutex_unlock(&dev->struct_mutex); for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { temp = drm_ctxbitmap_next(dev); DRM_DEBUG("drm_ctxbitmap_init : %d\n", temp); } return 0; } /** * Context bitmap cleanup. * * \param dev DRM device. * * Frees drm_device::ctx_bitmap and drm_device::context_sareas, while holding * the drm_device::struct_mutex lock. */ void drm_ctxbitmap_cleanup(drm_device_t * dev) { mutex_lock(&dev->struct_mutex); if (dev->context_sareas) drm_free(dev->context_sareas, sizeof(*dev->context_sareas) * dev->max_context, DRM_MEM_MAPS); drm_free((void *)dev->ctx_bitmap, PAGE_SIZE, DRM_MEM_CTXBITMAP); mutex_unlock(&dev->struct_mutex); } /*@}*/ /******************************************************************/ /** \name Per Context SAREA Support */ /*@{*/ /** * Get per-context SAREA. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx_priv_map structure. * \return zero on success or a negative number on failure. * * Gets the map from drm_device::context_sareas with the handle specified and * returns its handle. */ int drm_getsareactx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_ctx_priv_map_t __user *argp = (void __user *)arg; drm_ctx_priv_map_t request; drm_map_t *map; drm_map_list_t *_entry; if (copy_from_user(&request, argp, sizeof(request))) return -EFAULT; mutex_lock(&dev->struct_mutex); if (dev->max_context < 0 || request.ctx_id >= (unsigned)dev->max_context) { mutex_unlock(&dev->struct_mutex); return -EINVAL; } map = dev->context_sareas[request.ctx_id]; mutex_unlock(&dev->struct_mutex); request.handle = NULL; list_for_each_entry(_entry, &dev->maplist->head,head) { if (_entry->map == map) { request.handle = (void *)(unsigned long)_entry->user_token; break; } } if (request.handle == NULL) return -EINVAL; if (copy_to_user(argp, &request, sizeof(request))) return -EFAULT; return 0; } /** * Set per-context SAREA. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx_priv_map structure. * \return zero on success or a negative number on failure. * * Searches the mapping specified in \p arg and update the entry in * drm_device::context_sareas with it. */ int drm_setsareactx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_ctx_priv_map_t request; drm_map_t *map = NULL; drm_map_list_t *r_list = NULL; struct list_head *list; if (copy_from_user(&request, (drm_ctx_priv_map_t __user *) arg, sizeof(request))) return -EFAULT; mutex_lock(&dev->struct_mutex); list_for_each(list, &dev->maplist->head) { r_list = list_entry(list, drm_map_list_t, head); if (r_list->map && r_list->user_token == (unsigned long) request.handle) goto found; } bad: mutex_unlock(&dev->struct_mutex); return -EINVAL; found: map = r_list->map; if (!map) goto bad; if (dev->max_context < 0) goto bad; if (request.ctx_id >= (unsigned)dev->max_context) goto bad; dev->context_sareas[request.ctx_id] = map; mutex_unlock(&dev->struct_mutex); return 0; } /*@}*/ /******************************************************************/ /** \name The actual DRM context handling routines */ /*@{*/ /** * Switch context. * * \param dev DRM device. * \param old old context handle. * \param new new context handle. * \return zero on success or a negative number on failure. * * Attempt to set drm_device::context_flag. */ static int drm_context_switch(drm_device_t * dev, int old, int new) { if (test_and_set_bit(0, &dev->context_flag)) { DRM_ERROR("Reentering -- FIXME\n"); return -EBUSY; } DRM_DEBUG("Context switch from %d to %d\n", old, new); if (new == dev->last_context) { clear_bit(0, &dev->context_flag); return 0; } return 0; } /** * Complete context switch. * * \param dev DRM device. * \param new new context handle. * \return zero on success or a negative number on failure. * * Updates drm_device::last_context and drm_device::last_switch. Verifies the * hardware lock is held, clears the drm_device::context_flag and wakes up * drm_device::context_wait. */ static int drm_context_switch_complete(drm_device_t * dev, int new) { dev->last_context = new; /* PRE/POST: This is the _only_ writer. */ dev->last_switch = jiffies; if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) { DRM_ERROR("Lock isn't held after context switch\n"); } /* If a context switch is ever initiated when the kernel holds the lock, release that lock here. */ clear_bit(0, &dev->context_flag); wake_up(&dev->context_wait); return 0; } /** * Reserve contexts. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx_res structure. * \return zero on success or a negative number on failure. */ int drm_resctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_ctx_res_t res; drm_ctx_t __user *argp = (void __user *)arg; drm_ctx_t ctx; int i; if (copy_from_user(&res, argp, sizeof(res))) return -EFAULT; if (res.count >= DRM_RESERVED_CONTEXTS) { memset(&ctx, 0, sizeof(ctx)); for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) { ctx.handle = i; if (copy_to_user(&res.contexts[i], &ctx, sizeof(ctx))) return -EFAULT; } } res.count = DRM_RESERVED_CONTEXTS; if (copy_to_user(argp, &res, sizeof(res))) return -EFAULT; return 0; } /** * Add context. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * Get a new handle for the context and copy to userspace. */ int drm_addctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_ctx_list_t *ctx_entry; drm_ctx_t __user *argp = (void __user *)arg; drm_ctx_t ctx; if (copy_from_user(&ctx, argp, sizeof(ctx))) return -EFAULT; ctx.handle = drm_ctxbitmap_next(dev); if (ctx.handle == DRM_KERNEL_CONTEXT) { /* Skip kernel's context and get a new one. */ ctx.handle = drm_ctxbitmap_next(dev); } DRM_DEBUG("%d\n", ctx.handle); if (ctx.handle == -1) { DRM_DEBUG("Not enough free contexts.\n"); /* Should this return -EBUSY instead? */ return -ENOMEM; } if (ctx.handle != DRM_KERNEL_CONTEXT) { if (dev->driver->context_ctor) if (!dev->driver->context_ctor(dev, ctx.handle)) { DRM_DEBUG("Running out of ctxs or memory.\n"); return -ENOMEM; } } ctx_entry = drm_alloc(sizeof(*ctx_entry), DRM_MEM_CTXLIST); if (!ctx_entry) { DRM_DEBUG("out of memory\n"); return -ENOMEM; } INIT_LIST_HEAD(&ctx_entry->head); ctx_entry->handle = ctx.handle; ctx_entry->tag = priv; mutex_lock(&dev->ctxlist_mutex); list_add(&ctx_entry->head, &dev->ctxlist->head); ++dev->ctx_count; mutex_unlock(&dev->ctxlist_mutex); if (copy_to_user(argp, &ctx, sizeof(ctx))) return -EFAULT; return 0; } int drm_modctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { /* This does nothing */ return 0; } /** * Get context. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. */ int drm_getctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_ctx_t __user *argp = (void __user *)arg; drm_ctx_t ctx; if (copy_from_user(&ctx, argp, sizeof(ctx))) return -EFAULT; /* This is 0, because we don't handle any context flags */ ctx.flags = 0; if (copy_to_user(argp, &ctx, sizeof(ctx))) return -EFAULT; return 0; } /** * Switch context. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * Calls context_switch(). */ int drm_switchctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_ctx_t ctx; if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx))) return -EFAULT; DRM_DEBUG("%d\n", ctx.handle); return drm_context_switch(dev, dev->last_context, ctx.handle); } /** * New context. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * Calls context_switch_complete(). */ int drm_newctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_ctx_t ctx; if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx))) return -EFAULT; DRM_DEBUG("%d\n", ctx.handle); drm_context_switch_complete(dev, ctx.handle); return 0; } /** * Remove context. * * \param inode device inode. * \param filp file pointer. * \param cmd command. * \param arg user argument pointing to a drm_ctx structure. * \return zero on success or a negative number on failure. * * If not the special kernel context, calls ctxbitmap_free() to free the specified context. */ int drm_rmctx(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { drm_file_t *priv = filp->private_data; drm_device_t *dev = priv->head->dev; drm_ctx_t ctx; if (copy_from_user(&ctx, (drm_ctx_t __user *) arg, sizeof(ctx))) return -EFAULT; DRM_DEBUG("%d\n", ctx.handle); if (ctx.handle == DRM_KERNEL_CONTEXT + 1) { priv->remove_auth_on_close = 1; } if (ctx.handle != DRM_KERNEL_CONTEXT) { if (dev->driver->context_dtor) dev->driver->context_dtor(dev, ctx.handle); drm_ctxbitmap_free(dev, ctx.handle); } mutex_lock(&dev->ctxlist_mutex); if (!list_empty(&dev->ctxlist->head)) { drm_ctx_list_t *pos, *n; list_for_each_entry_safe(pos, n, &dev->ctxlist->head, head) { if (pos->handle == ctx.handle) { list_del(&pos->head); drm_free(pos, sizeof(*pos), DRM_MEM_CTXLIST); --dev->ctx_count; } } } mutex_unlock(&dev->ctxlist_mutex); return 0; } /*@}*/ 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 
/* gamma_dma.c -- DMA support for GMX 2000 -*- linux-c -*-
 * Created: Fri Mar 19 14:30:16 1999 by faith@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>
 *
 */

#define __NO_VERSION__
#include "drmP.h"
#include "gamma_drv.h"

#include <linux/interrupt.h>	/* For task queue support */


/* WARNING!!! MAGIC NUMBER!!!  The number of regions already added to the
   kernel must be specified here.  Currently, the number is 2.	This must
   match the order the X server uses for instantiating register regions ,
   or must be passed in a new ioctl. */
#define GAMMA_REG(reg)						   \
	(2							   \
	 + ((reg < 0x1000)					   \
	    ? 0							   \
	    : ((reg < 0x10000) ? 1 : ((reg < 0x11000) ? 2 : 3))))

#define GAMMA_OFF(reg)						   \
	((reg < 0x1000)						   \
	 ? reg							   \
	 : ((reg < 0x10000)					   \
	    ? (reg - 0x1000)					   \
	    : ((reg < 0x11000)					   \
	       ? (reg - 0x10000)				   \
	       : (reg - 0x11000))))

#define GAMMA_BASE(reg)	 ((unsigned long)dev->maplist[GAMMA_REG(reg)]->handle)
#define GAMMA_ADDR(reg)	 (GAMMA_BASE(reg) + GAMMA_OFF(reg))
#define GAMMA_DEREF(reg) *(__volatile__ int *)GAMMA_ADDR(reg)
#define GAMMA_READ(reg)	 GAMMA_DEREF(reg)
#define GAMMA_WRITE(reg,val) do { GAMMA_DEREF(reg) = val; } while (0)

#define GAMMA_BROADCASTMASK    0x9378
#define GAMMA_COMMANDINTENABLE 0x0c48
#define GAMMA_DMAADDRESS       0x0028
#define GAMMA_DMACOUNT	       0x0030
#define GAMMA_FILTERMODE       0x8c00
#define GAMMA_GCOMMANDINTFLAGS 0x0c50
#define GAMMA_GCOMMANDMODE     0x0c40
#define GAMMA_GCOMMANDSTATUS   0x0c60
#define GAMMA_GDELAYTIMER      0x0c38
#define GAMMA_GDMACONTROL      0x0060
#define GAMMA_GINTENABLE       0x0808
#define GAMMA_GINTFLAGS	       0x0810
#define GAMMA_INFIFOSPACE      0x0018
#define GAMMA_OUTFIFOWORDS     0x0020
#define GAMMA_OUTPUTFIFO       0x2000
#define GAMMA_SYNC	       0x8c40
#define GAMMA_SYNC_TAG	       0x0188

static inline void gamma_dma_dispatch(drm_device_t *dev, unsigned long address,
				      unsigned long length)
{
	GAMMA_WRITE(GAMMA_DMAADDRESS, virt_to_phys((void *)address));
	while (GAMMA_READ(GAMMA_GCOMMANDSTATUS) != 4)
		;
	GAMMA_WRITE(GAMMA_DMACOUNT, length / 4);
}

static inline void gamma_dma_quiescent_single(drm_device_t *dev)
{
	while (GAMMA_READ(GAMMA_DMACOUNT))
		;
	while (GAMMA_READ(GAMMA_INFIFOSPACE) < 3)
		;

	GAMMA_WRITE(GAMMA_FILTERMODE, 1 << 10);
	GAMMA_WRITE(GAMMA_SYNC, 0);
	
	do {
		while (!GAMMA_READ(GAMMA_OUTFIFOWORDS))
			;
	} while (GAMMA_READ(GAMMA_OUTPUTFIFO) != GAMMA_SYNC_TAG);
}

static inline void gamma_dma_quiescent_dual(drm_device_t *dev)
{
	while (GAMMA_READ(GAMMA_DMACOUNT))
		;
	while (GAMMA_READ(GAMMA_INFIFOSPACE) < 3)
		;

	GAMMA_WRITE(GAMMA_BROADCASTMASK, 3);

	GAMMA_WRITE(GAMMA_FILTERMODE, 1 << 10);
	GAMMA_WRITE(GAMMA_SYNC, 0);
	
				/* Read from first MX */
	do {
		while (!GAMMA_READ(GAMMA_OUTFIFOWORDS))
			;
	} while (GAMMA_READ(GAMMA_OUTPUTFIFO) != GAMMA_SYNC_TAG);
	
				/* Read from second MX */
	do {
		while (!GAMMA_READ(GAMMA_OUTFIFOWORDS + 0x10000))
			;
	} while (GAMMA_READ(GAMMA_OUTPUTFIFO + 0x10000) != GAMMA_SYNC_TAG);
}

static inline void gamma_dma_ready(drm_device_t *dev)
{
	while (GAMMA_READ(GAMMA_DMACOUNT))
		;
}

static inline int gamma_dma_is_ready(drm_device_t *dev)
{
	return !GAMMA_READ(GAMMA_DMACOUNT);
}

static void gamma_dma_service(int irq, void *device, struct pt_regs *regs)
{
	drm_device_t	 *dev = (drm_device_t *)device;
	drm_device_dma_t *dma = dev->dma;
	
	atomic_inc(&dev->total_irq);
	GAMMA_WRITE(GAMMA_GDELAYTIMER, 0xc350/2); /* 0x05S */
	GAMMA_WRITE(GAMMA_GCOMMANDINTFLAGS, 8);
	GAMMA_WRITE(GAMMA_GINTFLAGS, 0x2001);
	if (gamma_dma_is_ready(dev)) {
				/* Free previous buffer */
		if (test_and_set_bit(0, &dev->dma_flag)) {
			atomic_inc(&dma->total_missed_free);
			return;
		}
		if (dma->this_buffer) {
			drm_free_buffer(dev, dma->this_buffer);
			dma->this_buffer = NULL;
		}
		clear_bit(0, &dev->dma_flag);

				/* Dispatch new buffer */
		queue_task(&dev->tq, &tq_immediate);
		mark_bh(IMMEDIATE_BH);
	}
}

/* Only called by gamma_dma_schedule. */
static int gamma_do_dma(drm_device_t *dev, int locked)
{
	unsigned long	 address;
	unsigned long	 length;
	drm_buf_t	 *buf;
	int		 retcode = 0;
	drm_device_dma_t *dma = dev->dma;
#if DRM_DMA_HISTOGRAM
	cycles_t	 dma_start, dma_stop;
#endif

	if (test_and_set_bit(0, &dev->dma_flag)) {
		atomic_inc(&dma->total_missed_dma);
		return -EBUSY;
	}
	
#if DRM_DMA_HISTOGRAM
	dma_start = get_cycles();
#endif

	if (!dma->next_buffer) {
		DRM_ERROR("No next_buffer\n");
		clear_bit(0, &dev->dma_flag);
		return -EINVAL;
	}

	buf	= dma->next_buffer;
	address = (unsigned long)buf->address;
	length	= buf->used;

	DRM_DEBUG("context %d, buffer %d (%ld bytes)\n",
		  buf->context, buf->idx, length);

	if (buf->list == DRM_LIST_RECLAIM) {
		drm_clear_next_buffer(dev);
		drm_free_buffer(dev, buf);