path: root/drivers/gpu/drm/i915/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 acthd_reg = IS_I965G(dev) ? ACTHD_I965 : ACTHD;
	u32 last_acthd = I915_READ(acthd_reg);
	u32 acthd;
	u32 last_head = I915_READ(PRB0_HEAD) & HEAD_ADDR;
	int i;

	for (i = 0; i < 100000; i++) {
		ring->head = I915_READ(PRB0_HEAD) & HEAD_ADDR;
		acthd = I915_READ(acthd_reg);
		ring->space = ring->head - (ring->tail + 8);
		if (ring->space < 0)
			ring->space += ring->Size;
		if (ring->space >= n)
			return 0;

		if (dev_priv->sarea_priv)
			dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;

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

		last_head = ring->head;
		last_acthd = acthd;
		msleep_interruptible(10);

	}

	return -EBUSY;
}

/**
 * Sets up the hardware status page for devices that need a physical address
 * in the register.
 */
static int i915_init_phys_hws(struct drm_device *dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	/* Program Hardware Status Page */
	dev_priv->status_page_dmah =
		drm_pci_alloc(dev, PAGE_SIZE, PAGE_SIZE, 0xffffffff);

	if (!dev_priv->status_page_dmah) {
		DRM_ERROR("Can not allocate hardware status page\n");
		return -ENOMEM;
	}
	dev_priv->hw_status_page = dev_priv->status_page_dmah->vaddr;
	dev_priv->dma_status_page = dev_priv->status_page_dmah->busaddr;

	memset(dev_priv->hw_status_page, 0, PAGE_SIZE);

	I915_WRITE(HWS_PGA, dev_priv->dma_status_page);
	DRM_DEBUG("Enabled hardware status page\n");
	return 0;
}

/**
 * Frees the hardware status page, whether it's a physical address or a virtual
 * address set up by the X Server.
 */
static void i915_free_hws(struct drm_device *dev)
{
	drm_i915_private_t *dev_priv = dev->dev_private;
	if (dev_priv->status_page_dmah) {
		drm_pci_free(dev, dev_priv->status_page_dmah);
		dev_priv->status_page_dmah = NULL;
	}

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

	/* Need to rewrite hardware status page */
	I915_WRITE(HWS_PGA, 0x1ffff000);
}

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(PRB0_HEAD) & HEAD_ADDR;
	ring->tail = I915_READ(PRB0_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)
		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_enabled)
		drm_irq_uninstall(dev);

	if