path: root/drivers/char/drm/i915_dma.c

/* i915_dma.c -- DMA support for the I915 -*- linux-c -*-
 */
/*
 * Copyright 2003 Tungsten Graphics, Inc., Cedar Park, Texas.
 * 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 TUNGSTEN GRAPHICS 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.
 *
 */

#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"

/* Really want an OS-independent resettable timer.  Would like to have
 * this loop run for (eg) 3 sec, but have the timer reset every time
 * the head pointer changes, so that EBUSY only happens if the ring
 * actually stalls for (eg) 3 seconds.
 */
int i915_wait_ring(struct drm_device * dev, int n, const char *caller)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_ring_buffer_t *ring = &(dev_priv->ring);
	u32 last_head = I915_READ(LP_RING + RING_HEAD) & HEAD_ADDR;
	int i;

	for (i = 0; i < 10000; i++) {
		ring->head = I915_READ(LP_RING + RING_HEAD) & HEAD_ADDR;
		ring->space = ring->head - (ring->tail + 8);
		if (ring->space < 0)
			ring->space += ring->Size;
		if (ring->space >= n)
			return 0;

		dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;

		if (ring->head != last_head)
			i = 0;

		last_head = ring->head;
	}

	return -EBUSY;
}

void i915_kernel_lost_context(struct drm_device * dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	drm_i915_ring_buffer_t *ring = &(dev_priv->ring);

	ring->head = I915_READ(LP_RING + RING_HEAD) & HEAD_ADDR;
	ring->tail = I915_READ(LP_RING + RING_TAIL) & TAIL_ADDR;
	ring->space = ring->head - (ring->tail + 8);
	if (ring->space < 0)
		ring->space += ring->Size;

	if (ring->head == ring->tail)
		dev_priv->sarea_priv->perf_boxes |= I915_BOX_RING_EMPTY;
}

static int i915_dma_cleanup(struct drm_device * dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	/* 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)
		drm_irq_uninstall(dev);

	if (dev_priv->ring.virtual_start) {
		drm_core_ioremapfree(&dev_priv->ring.map, dev);
		dev_priv->ring.virtual_start = 0;
		dev_priv->ring.map.handle = 0;
		dev_priv->ring.map.size = 0;
	}

	if (dev_priv->status_page_dmah) {
		drm_pci_free(dev, dev_priv->status_page_dmah);
		dev_priv->status_page_dmah = NULL;
		/* Need to rewrite hardware status page */
		I915_WRITE(0x02080, 0x1ffff000);
	}

	if (dev_priv->status_gfx_addr) {
		dev_priv->status_gfx_addr = 0;
		drm_core_ioremapfree(&dev_priv->hws_map, dev);
		I915_WRITE(0x2080, 0x1ffff000);
	}

	return 0;
}

static int i915_initialize(struct drm_device * dev, drm_i915_init_t * init)
{
	drm_i915_private_t *dev_priv = dev->dev_private;

	dev_priv->sarea = drm_getsarea(dev);
	if (!dev_priv->sarea) {
		DRM_ERROR("can not find sarea!\n");
		i915_dma_cleanup(dev);
		return -EINVAL;
	}

	dev_priv->mmio_map = drm_core_findmap(dev, init->mmio_offset);
	if (!dev_priv->mmio_map) {
		i915_dma_cleanup(dev);
		DRM_ERROR("can not find mmio map!\n");
		return -EINVAL;
	}

	dev_priv->sarea_priv = (drm_i915_sarea_t *)
	    ((u8 *) dev_priv->sarea->handle + init->sarea_priv_offset);

	dev_priv->ring.Start = init->ring_start;
	dev_priv->ring.End = init->ring_end;
	dev_priv->ring.Size = init->ring_size;
	dev_priv->ring.tail_mask = dev_priv->ring.Size - 1;

	dev_priv->ring.map.offset = init->ring_start;
	dev_priv->ring.map.size = init->ring_size;
	dev_priv->ring.map.type = 0;
	dev_priv->ring.map.flags = 0