path: root/drivers/gpu/drm/savage/savage_bci.c

/* savage_bci.c -- BCI support for Savage
 *
 * Copyright 2004  Felix Kuehling
 * 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, sub license,
 * 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
 * NON-INFRINGEMENT. IN NO EVENT SHALL FELIX KUEHLING 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.
 */
#include "drmP.h"
#include "savage_drm.h"
#include "savage_drv.h"

/* Need a long timeout for shadow status updates can take a while
 * and so can waiting for events when the queue is full. */
#define SAVAGE_DEFAULT_USEC_TIMEOUT	1000000	/* 1s */
#define SAVAGE_EVENT_USEC_TIMEOUT	5000000	/* 5s */
#define SAVAGE_FREELIST_DEBUG		0

static int savage_do_cleanup_bci(struct drm_device *dev);

static int
savage_bci_wait_fifo_shadow(drm_savage_private_t * dev_priv, unsigned int n)
{
	uint32_t mask = dev_priv->status_used_mask;
	uint32_t threshold = dev_priv->bci_threshold_hi;
	uint32_t status;
	int i;

#if SAVAGE_BCI_DEBUG
	if (n > dev_priv->cob_size + SAVAGE_BCI_FIFO_SIZE - threshold)
		DRM_ERROR("Trying to emit %d words "
			  "(more than guaranteed space in COB)\n", n);
#endif

	for (i = 0; i < SAVAGE_DEFAULT_USEC_TIMEOUT; i++) {
		DRM_MEMORYBARRIER();
		status = dev_priv->status_ptr[0];
		if ((status & mask) < threshold)
			return 0;
		DRM_UDELAY(1);
	}

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

static int
savage_bci_wait_fifo_s3d(drm_savage_private_t * dev_priv, unsigned int n)
{
	uint32_t maxUsed = dev_priv->cob_size + SAVAGE_BCI_FIFO_SIZE - n;
	uint32_t status;
	int i;

	for (i = 0; i < SAVAGE_DEFAULT_USEC_TIMEOUT; i++) {
		status = SAVAGE_READ(SAVAGE_STATUS_WORD0);
		if ((status & SAVAGE_FIFO_USED_MASK_S3D) <= maxUsed)
			return 0;
		DRM_UDELAY(1);
	}

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

static int
savage_bci_wait_fifo_s4(drm_savage_private_t * dev_priv, unsigned int n)
{
	uint32_t maxUsed = dev_priv->cob_size + SAVAGE_BCI_FIFO_SIZE - n;
	uint32_t status;
	int i;

	for (i = 0; i < SAVAGE_DEFAULT_USEC_TIMEOUT; i++) {
		status = SAVAGE_READ(SAVAGE_ALT_STATUS_WORD0);
		if ((status & SAVAGE_FIFO_USED_MASK_S4) <= maxUsed)
			return 0;
		DRM_UDELAY(1);
	}

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

/*
 * Waiting for events.
 *
 * The BIOSresets the event tag to 0 on mode changes. Therefore we
 * never emit 0 to the event tag. If we find a 0 event tag we know the
 * BIOS stomped on it and return success assuming that the BIOS waited
 * for engine idle.
 *
 * Note: if the Xserver uses the event tag it has to follow the same
 * rule. Otherwise there may be glitches every 2^16 events.
 */
static int
savage_bci_wait_event_shadow(drm_savage_private_t * dev_priv, uint16_t e)
{
	uint32_t status;
	int i;

	for (i = 0; i < SAVAGE_EVENT_USEC_TIMEOUT; i++) {
		DRM_MEMORYBARRIER();
		status = dev_priv->status_ptr[1];
		if ((((status & 0xffff) - e) & 0xffff) <= 0x7fff ||
		    (status & 0xffff) == 0)
			return 0;
		DRM_UDELAY(1);
	}

#if SAVAGE_BCI_DEBUG
	DRM_ERROR("failed!\n");
	DRM_INFO("   status=0x%08x, e=0x%04x\n", status, e);
#endif

	return -EBUSY;
}

static int
savage_bci_wa