/* radeon_irq.c -- IRQ handling for radeon -*- linux-c -*-
 *
 * Copyright (C) The Weather Channel, Inc.  2002.  All Rights Reserved.
 *
 * The Weather Channel (TM) funded Tungsten Graphics to develop the
 * initial release of the Radeon 8500 driver under the XFree86 license.
 * This notice must be preserved.
 *
 * 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:
 *    Keith Whitwell <keith@tungstengraphics.com>
 *    Michel D�zer <michel@daenzer.net>
 */

#include "drmP.h"
#include "drm.h"
#include "radeon_drm.h"
#include "radeon_drv.h"

static __inline__ u32 radeon_acknowledge_irqs(drm_radeon_private_t * dev_priv,
					      u32 mask)
{
	u32 irqs = RADEON_READ(RADEON_GEN_INT_STATUS) & mask;
	if (irqs)
		RADEON_WRITE(RADEON_GEN_INT_STATUS, irqs);
	return irqs;
}

/* Interrupts - Used for device synchronization and flushing in the
 * following circumstances:
 *
 * - Exclusive FB access with hw idle:
 *    - Wait for GUI Idle (?) interrupt, then do normal flush.
 *
 * - Frame throttling, NV_fence:
 *    - Drop marker irq's into command stream ahead of time.
 *    - Wait on irq's with lock *not held*
 *    - Check each for termination condition
 *
 * - Internally in cp_getbuffer, etc:
 *    - as above, but wait with lock held???
 *
 * NOTE: These functions are misleadingly named -- the irq's aren't
 * tied to dma at all, this is just a hangover from dri prehistory.
 */

irqreturn_t radeon_driver_irq_handler(DRM_IRQ_ARGS)
{
	drm_device_t *dev = (drm_device_t *) arg;
	drm_radeon_private_t *dev_priv =
	    (drm_radeon_private_t *) dev->dev_private;
	u32 stat;

	/* Only consider the bits we're interested in - others could be used
	 * outside the DRM
	 */
	stat = radeon_acknowledge_irqs(dev_priv, (RADEON_SW_INT_TEST_ACK |
						  RADEON_CRTC_VBLANK_STAT));
	if (!stat)
		return IRQ_NONE;

	/* SW interrupt */
	if (stat & RADEON_SW_INT_TEST) {
		DRM_WAKEUP(&dev_priv->swi_queue);
	}

	/* VBLANK interrupt */
	if (stat & RADEON_CRTC_VBLANK_STAT) {
		atomic_inc(&dev->vbl_received);
		DRM_WAKEUP(&dev->vbl_queue);
		drm_vbl_send_signals(dev);
	}

	return IRQ_HANDLED;
}

static int radeon_emit_irq(drm_device_t * dev)
{
	drm_radeon_private_t *dev_priv = dev->dev_private;
	unsigned int ret;
	RING_LOCALS;

	atomic_inc(&dev_priv->swi_emitted);
	ret = atomic_read(&dev_priv->swi_emitted);

	BEGIN_RING(4);
	OUT_RING_REG(RADEON_LAST_SWI_REG, ret);
	OUT_RING_REG(RADEON_GEN_INT_STATUS, RADEON_SW_INT_FIRE);
	ADVANCE_RING();
	COMMIT_RING();

	return ret;
}

static int radeon_wait_irq(drm_device_t * dev, int swi_nr)
{
	drm_radeon_private_t *dev_priv =
	    (drm_radeon_private_t *) dev->dev_private;
	int ret = 0;

	if (RADEON_READ(RADEON_LAST_SWI_REG) >= swi_nr)
		return 0;

	dev_priv->stats.boxes |= RADEON_BOX_WAIT_IDLE;

	DRM_WAIT_ON(ret, dev_priv->swi_queue, 3 * DRM_HZ,
		    RADEON_READ(RADEON_LAST_SWI_REG) >= swi_nr);

	return ret;
}

int radeon_driver_vblank_wait(drm_device_t * dev, unsigned int *sequence)
{
	drm_radeon_private_t *dev_priv =
	    (drm_radeon_private_t *) dev->dev_private;
	unsigned int cur_vblank;
	int ret = 0;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	radeon_acknowledge_irqs(dev_priv, RADEON_CRTC_VBLANK_STAT);

	dev_priv->stats.boxes |= RADEON_BOX_WAIT_IDLE;

	/* Assume that the user has missed the current sequence number
	 * by about a day rather than she wants to wait for years
	 * using vertical blanks...
	 */
	DRM_WAIT_ON(ret, dev->vbl_queue, 3 * DRM_HZ,
		    (((cur_vblank = atomic_read(&dev->vbl_received))
		      - *sequence) <= (1 << 23)));

	*sequence = cur_vblank;

	return ret;
}

/* Needs the lock as it touches the ring.
 */
int radeon_irq_emit(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_radeon_private_t *dev_priv = dev->dev_private;
	drm_radeon_irq_emit_t emit;
	int result;

	LOCK_TEST_WITH_RETURN(dev, filp);

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(emit, (drm_radeon_irq_emit_t __user *) data,
				 sizeof(emit));

	result = radeon_emit_irq(dev);

	if (DRM_COPY_TO_USER(emit.irq_seq, &result, sizeof(int))) {
		DRM_ERROR("copy_to_user\n");
		return DRM_ERR(EFAULT);
	}

	return 0;
}

/* Doesn't need the hardware lock.
 */
int radeon_irq_wait(DRM_IOCTL_ARGS)
{
	DRM_DEVICE;
	drm_radeon_private_t *dev_priv = dev->dev_private;
	drm_radeon_irq_wait_t irqwait;

	if (!dev_priv) {
		DRM_ERROR("%s called with no initialization\n", __FUNCTION__);
		return DRM_ERR(EINVAL);
	}

	DRM_COPY_FROM_USER_IOCTL(irqwait, (drm_radeon_irq_wait_t __user *) data,
				 sizeof(irqwait));

	return radeon_wait_irq(dev, irqwait.irq_seq);
}

/* drm_dma.h hooks
*/
void radeon_driver_irq_preinstall(drm_device_t * dev)
{
	drm_radeon_private_t *dev_priv =
	    (drm_radeon_private_t *) dev->dev_private;

	/* Disable *all* interrupts */
	RADEON_WRITE(RADEON_GEN_INT_CNTL, 0);

	/* Clear bits if they're already high */
	radeon_acknowledge_irqs(dev_priv, (RADEON_SW_INT_TEST_ACK |
					   RADEON_CRTC_VBLANK_STAT));
}

void radeon_driver_irq_postinstall(drm_device_t * dev)
{
	drm_radeon_private_t *dev_priv =
	    (drm_radeon_private_t *) dev->dev_private;

	atomic_set(&dev_priv->swi_emitted, 0);
	DRM_INIT_WAITQUEUE(&dev_priv->swi_queue);

	/* Turn on SW and VBL ints */
	RADEON_WRITE(RADEON_GEN_INT_CNTL,
		     RADEON_CRTC_VBLANK_MASK | RADEON_SW_INT_ENABLE);
}

void radeon_driver_irq_uninstall(drm_device_t * dev)
{
	drm_radeon_private_t *dev_priv =
	    (drm_radeon_private_t *) dev->dev_private;
	if (!dev_priv)
		return;

	/* Disable *all* interrupts */
	RADEON_WRITE(RADEON_GEN_INT_CNTL, 0);
}