/* i915_irq.c -- IRQ 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 <linux/sysrq.h>
#include "drmP.h"
#include "drm.h"
#include "i915_drm.h"
#include "i915_drv.h"
#include "i915_trace.h"
#include "intel_drv.h"

#define MAX_NOPID ((u32)~0)

/**
 * Interrupts that are always left unmasked.
 *
 * Since pipe events are edge-triggered from the PIPESTAT register to IIR,
 * we leave them always unmasked in IMR and then control enabling them through
 * PIPESTAT alone.
 */
#define I915_INTERRUPT_ENABLE_FIX (I915_ASLE_INTERRUPT |                 \
                                   I915_DISPLAY_PIPE_A_EVENT_INTERRUPT | \
                                   I915_DISPLAY_PIPE_B_EVENT_INTERRUPT | \
                                   I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)

/** Interrupts that we mask and unmask at runtime. */
#define I915_INTERRUPT_ENABLE_VAR (I915_USER_INTERRUPT)

#define I915_PIPE_VBLANK_STATUS (PIPE_START_VBLANK_INTERRUPT_STATUS |\
                                 PIPE_VBLANK_INTERRUPT_STATUS)

#define I915_PIPE_VBLANK_ENABLE (PIPE_START_VBLANK_INTERRUPT_ENABLE |\
                                 PIPE_VBLANK_INTERRUPT_ENABLE)

#define DRM_I915_VBLANK_PIPE_ALL        (DRM_I915_VBLANK_PIPE_A | \
                                         DRM_I915_VBLANK_PIPE_B)

void
igdng_enable_graphics_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        if ((dev_priv->gt_irq_mask_reg & mask) != 0) {
                dev_priv->gt_irq_mask_reg &= ~mask;
                I915_WRITE(GTIMR, dev_priv->gt_irq_mask_reg);
                (void) I915_READ(GTIMR);
        }
}

static inline void
igdng_disable_graphics_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        if ((dev_priv->gt_irq_mask_reg & mask) != mask) {
                dev_priv->gt_irq_mask_reg |= mask;
                I915_WRITE(GTIMR, dev_priv->gt_irq_mask_reg);
                (void) I915_READ(GTIMR);
        }
}

/* For display hotplug interrupt */
void
igdng_enable_display_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        if ((dev_priv->irq_mask_reg & mask) != 0) {
                dev_priv->irq_mask_reg &= ~mask;
                I915_WRITE(DEIMR, dev_priv->irq_mask_reg);
                (void) I915_READ(DEIMR);
        }
}

static inline void
igdng_disable_display_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        if ((dev_priv->irq_mask_reg & mask) != mask) {
                dev_priv->irq_mask_reg |= mask;
                I915_WRITE(DEIMR, dev_priv->irq_mask_reg);
                (void) I915_READ(DEIMR);
        }
}

void
i915_enable_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        if ((dev_priv->irq_mask_reg & mask) != 0) {
                dev_priv->irq_mask_reg &= ~mask;
                I915_WRITE(IMR, dev_priv->irq_mask_reg);
                (void) I915_READ(IMR);
        }
}

static inline void
i915_disable_irq(drm_i915_private_t *dev_priv, u32 mask)
{
        if ((dev_priv->irq_mask_reg & mask) != mask) {
                dev_priv->irq_mask_reg |= mask;
                I915_WRITE(IMR, dev_priv->irq_mask_reg);
                (void) I915_READ(IMR);
        }
}

static inline u32
i915_pipestat(int pipe)
{
        if (pipe == 0)
                return PIPEASTAT;
        if (pipe == 1)
                return PIPEBSTAT;
        BUG();
}

void
i915_enable_pipestat(drm_i915_private_t *dev_priv, int pipe, u32 mask)
{
        if ((dev_priv->pipestat[pipe] & mask) != mask) {
                u32 reg = i915_pipestat(pipe);

                dev_priv->pipestat[pipe] |= mask;
                /* Enable the interrupt, clear any pending status */
                I915_WRITE(reg, dev_priv->pipestat[pipe] | (mask >> 16));
                (void) I915_READ(reg);
        }
}

void
i915_disable_pipestat(drm_i915_private_t *dev_priv, int pipe, u32 mask)
{
        if ((dev_priv->pipestat[pipe] & mask) != 0) {
                u32 reg = i915_pipestat(pipe);

                dev_priv->pipestat[pipe] &= ~mask;
                I915_WRITE(reg, dev_priv->pipestat[pipe]);
                (void) I915_READ(reg);
        }
}

/**
 * i915_pipe_enabled - check if a pipe is enabled
 * @dev: DRM device
 * @pipe: pipe to check
 *
 * Reading certain registers when the pipe is disabled can hang the chip.
 * Use this routine to make sure the PLL is running and the pipe is active
 * before reading such registers if unsure.
 */
static int
i915_pipe_enabled(struct drm_device *dev, int pipe)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long pipeconf = pipe ? PIPEBCONF : PIPEACONF;

        if (I915_READ(pipeconf) & PIPEACONF_ENABLE)
                return 1;

        return 0;
}

/* Called from drm generic code, passed a 'crtc', which
 * we use as a pipe index
 */
u32 i915_get_vblank_counter(struct drm_device *dev, int pipe)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long high_frame;
        unsigned long low_frame;
        u32 high1, high2, low, count;

        high_frame = pipe ? PIPEBFRAMEHIGH : PIPEAFRAMEHIGH;
        low_frame = pipe ? PIPEBFRAMEPIXEL : PIPEAFRAMEPIXEL;

        if (!i915_pipe_enabled(dev, pipe)) {
                DRM_DEBUG("trying to get vblank count for disabled pipe %d\n", pipe);
                return 0;
        }

        /*
         * High & low register fields aren't synchronized, so make sure
         * we get a low value that's stable across two reads of the high
         * register.
         */
        do {
                high1 = ((I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
                         PIPE_FRAME_HIGH_SHIFT);
                low =  ((I915_READ(low_frame) & PIPE_FRAME_LOW_MASK) >>
                        PIPE_FRAME_LOW_SHIFT);
                high2 = ((I915_READ(high_frame) & PIPE_FRAME_HIGH_MASK) >>
                         PIPE_FRAME_HIGH_SHIFT);
        } while (high1 != high2);

        count = (high1 << 8) | low;

        return count;
}

u32 gm45_get_vblank_counter(struct drm_device *dev, int pipe)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        int reg = pipe ? PIPEB_FRMCOUNT_GM45 : PIPEA_FRMCOUNT_GM45;

        if (!i915_pipe_enabled(dev, pipe)) {
                DRM_DEBUG("trying to get vblank count for disabled pipe %d\n", pipe);
                return 0;
        }

        return I915_READ(reg);
}

/*
 * Handle hotplug events outside the interrupt handler proper.
 */
static void i915_hotplug_work_func(struct work_struct *work)
{
        drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
                                                    hotplug_work);
        struct drm_device *dev = dev_priv->dev;
        struct drm_mode_config *mode_config = &dev->mode_config;
        struct drm_connector *connector;

        if (mode_config->num_connector) {
                list_for_each_entry(connector, &mode_config->connector_list, head) {
                        struct intel_output *intel_output = to_intel_output(connector);
        
                        if (intel_output->hot_plug)
                                (*intel_output->hot_plug) (intel_output);
                }
        }
        /* Just fire off a uevent and let userspace tell us what to do */
        drm_sysfs_hotplug_event(dev);
}

irqreturn_t igdng_irq_handler(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        int ret = IRQ_NONE;
        u32 de_iir, gt_iir, de_ier;
        u32 new_de_iir, new_gt_iir;
        struct drm_i915_master_private *master_priv;

        /* disable master interrupt before clearing iir  */
        de_ier = I915_READ(DEIER);
        I915_WRITE(DEIER, de_ier & ~DE_MASTER_IRQ_CONTROL);
        (void)I915_READ(DEIER);

        de_iir = I915_READ(DEIIR);
        gt_iir = I915_READ(GTIIR);

        for (;;) {
                if (de_iir == 0 && gt_iir == 0)
                        break;

                ret = IRQ_HANDLED;

                I915_WRITE(DEIIR, de_iir);
                new_de_iir = I915_READ(DEIIR);
                I915_WRITE(GTIIR, gt_iir);
                new_gt_iir = I915_READ(GTIIR);

                if (dev->primary->master) {
                        master_priv = dev->primary->master->driver_priv;
                        if (master_priv->sarea_priv)
                                master_priv->sarea_priv->last_dispatch =
                                        READ_BREADCRUMB(dev_priv);
                }

                if (gt_iir & GT_USER_INTERRUPT) {
                        u32 seqno = i915_get_gem_seqno(dev);
                        dev_priv->mm.irq_gem_seqno = seqno;
                        trace_i915_gem_request_complete(dev, seqno);
                        DRM_WAKEUP(&dev_priv->irq_queue);
                }

                de_iir = new_de_iir;
                gt_iir = new_gt_iir;
        }

        I915_WRITE(DEIER, de_ier);
        (void)I915_READ(DEIER);

        return ret;
}

/**
 * i915_error_work_func - do process context error handling work
 * @work: work struct
 *
 * Fire an error uevent so userspace can see that a hang or error
 * was detected.
 */
static void i915_error_work_func(struct work_struct *work)
{
        drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
                                                    error_work);
        struct drm_device *dev = dev_priv->dev;
        char *error_event[] = { "ERROR=1", NULL };
        char *reset_event[] = { "RESET=1", NULL };
        char *reset_done_event[] = { "ERROR=0", NULL };

        DRM_DEBUG("generating error event\n");
        kobject_uevent_env(&dev->primary->kdev.kobj, KOBJ_CHANGE, error_event);

        if (atomic_read(&dev_priv->mm.wedged)) {
                if (IS_I965G(dev)) {
                        DRM_DEBUG("resetting chip\n");
                        kobject_uevent_env(&dev->primary->kdev.kobj, KOBJ_CHANGE, reset_event);
                        if (!i965_reset(dev, GDRST_RENDER)) {
                                atomic_set(&dev_priv->mm.wedged, 0);
                                kobject_uevent_env(&dev->primary->kdev.kobj, KOBJ_CHANGE, reset_done_event);
                        }
                } else {
                        printk("reboot required\n");
                }
        }
}

/**
 * i915_capture_error_state - capture an error record for later analysis
 * @dev: drm device
 *
 * Should be called when an error is detected (either a hang or an error
 * interrupt) to capture error state from the time of the error.  Fills
 * out a structure which becomes available in debugfs for user level tools
 * to pick up.
 */
static void i915_capture_error_state(struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        struct drm_i915_error_state *error;
        unsigned long flags;

        spin_lock_irqsave(&dev_priv->error_lock, flags);
        if (dev_priv->first_error)
                goto out;

        error = kmalloc(sizeof(*error), GFP_ATOMIC);
        if (!error) {
                DRM_DEBUG("out ot memory, not capturing error state\n");
                goto out;
        }

        error->eir = I915_READ(EIR);
        error->pgtbl_er = I915_READ(PGTBL_ER);
        error->pipeastat = I915_READ(PIPEASTAT);
        error->pipebstat = I915_READ(PIPEBSTAT);
        error->instpm = I915_READ(INSTPM);
        if (!IS_I965G(dev)) {
                error->ipeir = I915_READ(IPEIR);
                error->ipehr = I915_READ(IPEHR);
                error->instdone = I915_READ(INSTDONE);
                error->acthd = I915_READ(ACTHD);
        } else {
                error->ipeir = I915_READ(IPEIR_I965);
                error->ipehr = I915_READ(IPEHR_I965);
                error->instdone = I915_READ(INSTDONE_I965);
                error->instps = I915_READ(INSTPS);
                error->instdone1 = I915_READ(INSTDONE1);
                error->acthd = I915_READ(ACTHD_I965);
        }

        do_gettimeofday(&error->time);

        dev_priv->first_error = error;

out:
        spin_unlock_irqrestore(&dev_priv->error_lock, flags);
}

/**
 * i915_handle_error - handle an error interrupt
 * @dev: drm device
 *
 * Do some basic checking of regsiter state at error interrupt time and
 * dump it to the syslog.  Also call i915_capture_error_state() to make
 * sure we get a record and make it available in debugfs.  Fire a uevent
 * so userspace knows something bad happened (should trigger collection
 * of a ring dump etc.).
 */
static void i915_handle_error(struct drm_device *dev, bool wedged)
{
        struct drm_i915_private *dev_priv = dev->dev_private;
        u32 eir = I915_READ(EIR);
        u32 pipea_stats = I915_READ(PIPEASTAT);
        u32 pipeb_stats = I915_READ(PIPEBSTAT);

        i915_capture_error_state(dev);

        printk(KERN_ERR "render error detected, EIR: 0x%08x\n",
               eir);

        if (IS_G4X(dev)) {
                if (eir & (GM45_ERROR_MEM_PRIV | GM45_ERROR_CP_PRIV)) {
                        u32 ipeir = I915_READ(IPEIR_I965);

                        printk(KERN_ERR "  IPEIR: 0x%08x\n",
                               I915_READ(IPEIR_I965));
                        printk(KERN_ERR "  IPEHR: 0x%08x\n",
                               I915_READ(IPEHR_I965));
                        printk(KERN_ERR "  INSTDONE: 0x%08x\n",
                               I915_READ(INSTDONE_I965));
                        printk(KERN_ERR "  INSTPS: 0x%08x\n",
                               I915_READ(INSTPS));
                        printk(KERN_ERR "  INSTDONE1: 0x%08x\n",
                               I915_READ(INSTDONE1));
                        printk(KERN_ERR "  ACTHD: 0x%08x\n",
                               I915_READ(ACTHD_I965));
                        I915_WRITE(IPEIR_I965, ipeir);
                        (void)I915_READ(IPEIR_I965);
                }
                if (eir & GM45_ERROR_PAGE_TABLE) {
                        u32 pgtbl_err = I915_READ(PGTBL_ER);
                        printk(KERN_ERR "page table error\n");
                        printk(KERN_ERR "  PGTBL_ER: 0x%08x\n",
                               pgtbl_err);
                        I915_WRITE(PGTBL_ER, pgtbl_err);
                        (void)I915_READ(PGTBL_ER);
                }
        }

        if (IS_I9XX(dev)) {
                if (eir & I915_ERROR_PAGE_TABLE) {
                        u32 pgtbl_err = I915_READ(PGTBL_ER);
                        printk(KERN_ERR "page table error\n");
                        printk(KERN_ERR "  PGTBL_ER: 0x%08x\n",
                               pgtbl_err);
                        I915_WRITE(PGTBL_ER, pgtbl_err);
                        (void)I915_READ(PGTBL_ER);
                }
        }

        if (eir & I915_ERROR_MEMORY_REFRESH) {
                printk(KERN_ERR "memory refresh error\n");
                printk(KERN_ERR "PIPEASTAT: 0x%08x\n",
                       pipea_stats);
                printk(KERN_ERR "PIPEBSTAT: 0x%08x\n",
                       pipeb_stats);
                /* pipestat has already been acked */
        }
        if (eir & I915_ERROR_INSTRUCTION) {
                printk(KERN_ERR "instruction error\n");
                printk(KERN_ERR "  INSTPM: 0x%08x\n",
                       I915_READ(INSTPM));
                if (!IS_I965G(dev)) {
                        u32 ipeir = I915_READ(IPEIR);

                        printk(KERN_ERR "  IPEIR: 0x%08x\n",
                               I915_READ(IPEIR));
                        printk(KERN_ERR "  IPEHR: 0x%08x\n",
                               I915_READ(IPEHR));
                        printk(KERN_ERR "  INSTDONE: 0x%08x\n",
                               I915_READ(INSTDONE));
                        printk(KERN_ERR "  ACTHD: 0x%08x\n",
                               I915_READ(ACTHD));
                        I915_WRITE(IPEIR, ipeir);
                        (void)I915_READ(IPEIR);
                } else {
                        u32 ipeir = I915_READ(IPEIR_I965);

                        printk(KERN_ERR "  IPEIR: 0x%08x\n",
                               I915_READ(IPEIR_I965));
                        printk(KERN_ERR "  IPEHR: 0x%08x\n",
                               I915_READ(IPEHR_I965));
                        printk(KERN_ERR "  INSTDONE: 0x%08x\n",
                               I915_READ(INSTDONE_I965));
                        printk(KERN_ERR "  INSTPS: 0x%08x\n",
                               I915_READ(INSTPS));
                        printk(KERN_ERR "  INSTDONE1: 0x%08x\n",
                               I915_READ(INSTDONE1));
                        printk(KERN_ERR "  ACTHD: 0x%08x\n",
                               I915_READ(ACTHD_I965));
                        I915_WRITE(IPEIR_I965, ipeir);
                        (void)I915_READ(IPEIR_I965);
                }
        }

        I915_WRITE(EIR, eir);
        (void)I915_READ(EIR);
        eir = I915_READ(EIR);
        if (eir) {
                /*
                 * some errors might have become stuck,
                 * mask them.
                 */
                DRM_ERROR("EIR stuck: 0x%08x, masking\n", eir);
                I915_WRITE(EMR, I915_READ(EMR) | eir);
                I915_WRITE(IIR, I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT);
        }

        if (wedged) {
                atomic_set(&dev_priv->mm.wedged, 1);

                /*
                 * Wakeup waiting processes so they don't hang
                 */
                printk("i915: Waking up sleeping processes\n");
                DRM_WAKEUP(&dev_priv->irq_queue);
        }

        queue_work(dev_priv->wq, &dev_priv->error_work);
}

irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
{
        struct drm_device *dev = (struct drm_device *) arg;
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        struct drm_i915_master_private *master_priv;
        u32 iir, new_iir;
        u32 pipea_stats, pipeb_stats;
        u32 vblank_status;
        u32 vblank_enable;
        int vblank = 0;
        unsigned long irqflags;
        int irq_received;
        int ret = IRQ_NONE;

        atomic_inc(&dev_priv->irq_received);

        if (IS_IGDNG(dev))
                return igdng_irq_handler(dev);

        iir = I915_READ(IIR);

        if (IS_I965G(dev)) {
                vblank_status = I915_START_VBLANK_INTERRUPT_STATUS;
                vblank_enable = PIPE_START_VBLANK_INTERRUPT_ENABLE;
        } else {
                vblank_status = I915_VBLANK_INTERRUPT_STATUS;
                vblank_enable = I915_VBLANK_INTERRUPT_ENABLE;
        }

        for (;;) {
                irq_received = iir != 0;

                /* Can't rely on pipestat interrupt bit in iir as it might
                 * have been cleared after the pipestat interrupt was received.
                 * It doesn't set the bit in iir again, but it still produces
                 * interrupts (for non-MSI).
                 */
                spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
                pipea_stats = I915_READ(PIPEASTAT);
                pipeb_stats = I915_READ(PIPEBSTAT);

                if (iir & I915_RENDER_COMMAND_PARSER_ERROR_INTERRUPT)
                        i915_handle_error(dev, false);

                /*
                 * Clear the PIPE(A|B)STAT regs before the IIR
                 */
                if (pipea_stats & 0x8000ffff) {
                        if (pipea_stats &  PIPE_FIFO_UNDERRUN_STATUS)
                                DRM_DEBUG("pipe a underrun\n");
                        I915_WRITE(PIPEASTAT, pipea_stats);
                        irq_received = 1;
                }

                if (pipeb_stats & 0x8000ffff) {
                        if (pipeb_stats &  PIPE_FIFO_UNDERRUN_STATUS)
                                DRM_DEBUG("pipe b underrun\n");
                        I915_WRITE(PIPEBSTAT, pipeb_stats);
                        irq_received = 1;
                }
                spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);

                if (!irq_received)
                        break;

                ret = IRQ_HANDLED;

                /* Consume port.  Then clear IIR or we'll miss events */
                if ((I915_HAS_HOTPLUG(dev)) &&
                    (iir & I915_DISPLAY_PORT_INTERRUPT)) {
                        u32 hotplug_status = I915_READ(PORT_HOTPLUG_STAT);

                        DRM_DEBUG("hotplug event received, stat 0x%08x\n",
                                  hotplug_status);
                        if (hotplug_status & dev_priv->hotplug_supported_mask)
                                queue_work(dev_priv->wq,
                                           &dev_priv->hotplug_work);

                        I915_WRITE(PORT_HOTPLUG_STAT, hotplug_status);
                        I915_READ(PORT_HOTPLUG_STAT);

                        /* EOS interrupts occurs */
                        if (IS_IGD(dev) &&
                                (hotplug_status & CRT_EOS_INT_STATUS)) {
                                u32 temp;

                                DRM_DEBUG("EOS interrupt occurs\n");
                                /* status is already cleared */
                                temp = I915_READ(ADPA);
                                temp &= ~ADPA_DAC_ENABLE;
                                I915_WRITE(ADPA, temp);

                                temp = I915_READ(PORT_HOTPLUG_EN);
                                temp &= ~CRT_EOS_INT_EN;
                                I915_WRITE(PORT_HOTPLUG_EN, temp);

                                temp = I915_READ(PORT_HOTPLUG_STAT);
                                if (temp & CRT_EOS_INT_STATUS)
                                        I915_WRITE(PORT_HOTPLUG_STAT,
                                                CRT_EOS_INT_STATUS);
                        }
                }

                I915_WRITE(IIR, iir);
                new_iir = I915_READ(IIR); /* Flush posted writes */

                if (dev->primary->master) {
                        master_priv = dev->primary->master->driver_priv;
                        if (master_priv->sarea_priv)
                                master_priv->sarea_priv->last_dispatch =
                                        READ_BREADCRUMB(dev_priv);
                }

                if (iir & I915_USER_INTERRUPT) {
                        u32 seqno = i915_get_gem_seqno(dev);
                        dev_priv->mm.irq_gem_seqno = seqno;
                        trace_i915_gem_request_complete(dev, seqno);
                        DRM_WAKEUP(&dev_priv->irq_queue);
                        dev_priv->hangcheck_count = 0;
                        mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);
                }

                if (pipea_stats & vblank_status) {
                        vblank++;
                        drm_handle_vblank(dev, 0);
                }

                if (pipeb_stats & vblank_status) {
                        vblank++;
                        drm_handle_vblank(dev, 1);
                }

                if ((pipeb_stats & I915_LEGACY_BLC_EVENT_STATUS) ||
                    (iir & I915_ASLE_INTERRUPT))
                        opregion_asle_intr(dev);

                /* With MSI, interrupts are only generated when iir
                 * transitions from zero to nonzero.  If another bit got
                 * set while we were handling the existing iir bits, then
                 * we would never get another interrupt.
                 *
                 * This is fine on non-MSI as well, as if we hit this path
                 * we avoid exiting the interrupt handler only to generate
                 * another one.
                 *
                 * Note that for MSI this could cause a stray interrupt report
                 * if an interrupt landed in the time between writing IIR and
                 * the posting read.  This should be rare enough to never
                 * trigger the 99% of 100,000 interrupts test for disabling
                 * stray interrupts.
                 */
                iir = new_iir;
        }

        return ret;
}

static int i915_emit_irq(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        struct drm_i915_master_private *master_priv = dev->primary->master->driver_priv;
        RING_LOCALS;

        i915_kernel_lost_context(dev);

        DRM_DEBUG("\n");

        dev_priv->counter++;
        if (dev_priv->counter > 0x7FFFFFFFUL)
                dev_priv->counter = 1;
        if (master_priv->sarea_priv)
                master_priv->sarea_priv->last_enqueue = dev_priv->counter;

        BEGIN_LP_RING(4);
        OUT_RING(MI_STORE_DWORD_INDEX);
        OUT_RING(I915_BREADCRUMB_INDEX << MI_STORE_DWORD_INDEX_SHIFT);
        OUT_RING(dev_priv->counter);
        OUT_RING(MI_USER_INTERRUPT);
        ADVANCE_LP_RING();

        return dev_priv->counter;
}

void i915_user_irq_get(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
        if (dev->irq_enabled && (++dev_priv->user_irq_refcount == 1)) {
                if (IS_IGDNG(dev))
                        igdng_enable_graphics_irq(dev_priv, GT_USER_INTERRUPT);
                else
                        i915_enable_irq(dev_priv, I915_USER_INTERRUPT);
        }
        spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
}

void i915_user_irq_put(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long irqflags;

        spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
        BUG_ON(dev->irq_enabled && dev_priv->user_irq_refcount <= 0);
        if (dev->irq_enabled && (--dev_priv->user_irq_refcount == 0)) {
                if (IS_IGDNG(dev))
                        igdng_disable_graphics_irq(dev_priv, GT_USER_INTERRUPT);
                else
                        i915_disable_irq(dev_priv, I915_USER_INTERRUPT);
        }
        spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
}

void i915_trace_irq_get(struct drm_device *dev, u32 seqno)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

        if (dev_priv->trace_irq_seqno == 0)
                i915_user_irq_get(dev);

        dev_priv->trace_irq_seqno = seqno;
}

static int i915_wait_irq(struct drm_device * dev, int irq_nr)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        struct drm_i915_master_private *master_priv = dev->primary->master->driver_priv;
        int ret = 0;

        DRM_DEBUG("irq_nr=%d breadcrumb=%d\n", irq_nr,
                  READ_BREADCRUMB(dev_priv));

        if (READ_BREADCRUMB(dev_priv) >= irq_nr) {
                if (master_priv->sarea_priv)
                        master_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);
                return 0;
        }

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

        i915_user_irq_get(dev);
        DRM_WAIT_ON(ret, dev_priv->irq_queue, 3 * DRM_HZ,
                    READ_BREADCRUMB(dev_priv) >= irq_nr);
        i915_user_irq_put(dev);

        if (ret == -EBUSY) {
                DRM_ERROR("EBUSY -- rec: %d emitted: %d\n",
                          READ_BREADCRUMB(dev_priv), (int)dev_priv->counter);
        }

        return ret;
}

/* Needs the lock as it touches the ring.
 */
int i915_irq_emit(struct drm_device *dev, void *data,
                         struct drm_file *file_priv)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        drm_i915_irq_emit_t *emit = data;
        int result;

        if (!dev_priv || !dev_priv->ring.virtual_start) {
                DRM_ERROR("called with no initialization\n");
                return -EINVAL;
        }

        RING_LOCK_TEST_WITH_RETURN(dev, file_priv);

        mutex_lock(&dev->struct_mutex);
        result = i915_emit_irq(dev);
        mutex_unlock(&dev->struct_mutex);

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

        return 0;
}

/* Doesn't need the hardware lock.
 */
int i915_irq_wait(struct drm_device *dev, void *data,
                         struct drm_file *file_priv)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        drm_i915_irq_wait_t *irqwait = data;

        if (!dev_priv) {
                DRM_ERROR("called with no initialization\n");
                return -EINVAL;
        }

        return i915_wait_irq(dev, irqwait->irq_seq);
}

/* Called from drm generic code, passed 'crtc' which
 * we use as a pipe index
 */
int i915_enable_vblank(struct drm_device *dev, int pipe)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long irqflags;
        int pipeconf_reg = (pipe == 0) ? PIPEACONF : PIPEBCONF;
        u32 pipeconf;

        pipeconf = I915_READ(pipeconf_reg);
        if (!(pipeconf & PIPEACONF_ENABLE))
                return -EINVAL;

        if (IS_IGDNG(dev))
                return 0;

        spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
        if (IS_I965G(dev))
                i915_enable_pipestat(dev_priv, pipe,
                                     PIPE_START_VBLANK_INTERRUPT_ENABLE);
        else
                i915_enable_pipestat(dev_priv, pipe,
                                     PIPE_VBLANK_INTERRUPT_ENABLE);
        spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
        return 0;
}

/* Called from drm generic code, passed 'crtc' which
 * we use as a pipe index
 */
void i915_disable_vblank(struct drm_device *dev, int pipe)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long irqflags;

        if (IS_IGDNG(dev))
                return;

        spin_lock_irqsave(&dev_priv->user_irq_lock, irqflags);
        i915_disable_pipestat(dev_priv, pipe,
                              PIPE_VBLANK_INTERRUPT_ENABLE |
                              PIPE_START_VBLANK_INTERRUPT_ENABLE);
        spin_unlock_irqrestore(&dev_priv->user_irq_lock, irqflags);
}

void i915_enable_interrupt (struct drm_device *dev)
{
        struct drm_i915_private *dev_priv = dev->dev_private;

        if (!IS_IGDNG(dev))
                opregion_enable_asle(dev);
        dev_priv->irq_enabled = 1;
}


/* Set the vblank monitor pipe
 */
int i915_vblank_pipe_set(struct drm_device *dev, void *data,
                         struct drm_file *file_priv)
{
        drm_i915_private_t *dev_priv = dev->dev_private;

        if (!dev_priv) {
                DRM_ERROR("called with no initialization\n");
                return -EINVAL;
        }

        return 0;
}

int i915_vblank_pipe_get(struct drm_device *dev, void *data,
                         struct drm_file *file_priv)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        drm_i915_vblank_pipe_t *pipe = data;

        if (!dev_priv) {
                DRM_ERROR("called with no initialization\n");
                return -EINVAL;
        }

        pipe->pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;

        return 0;
}

/**
 * Schedule buffer swap at given vertical blank.
 */
int i915_vblank_swap(struct drm_device *dev, void *data,
                     struct drm_file *file_priv)
{
        /* The delayed swap mechanism was fundamentally racy, and has been
         * removed.  The model was that the client requested a delayed flip/swap
         * from the kernel, then waited for vblank before continuing to perform
         * rendering.  The problem was that the kernel might wake the client
         * up before it dispatched the vblank swap (since the lock has to be
         * held while touching the ringbuffer), in which case the client would
         * clear and start the next frame before the swap occurred, and
         * flicker would occur in addition to likely missing the vblank.
         *
         * In the absence of this ioctl, userland falls back to a correct path
         * of waiting for a vblank, then dispatching the swap on its own.
         * Context switching to userland and back is plenty fast enough for
         * meeting the requirements of vblank swapping.
         */
        return -EINVAL;
}

struct drm_i915_gem_request *i915_get_tail_request(struct drm_device *dev) {
        drm_i915_private_t *dev_priv = dev->dev_private;
        return list_entry(dev_priv->mm.request_list.prev, struct drm_i915_gem_request, list);
}

/**
 * This is called when the chip hasn't reported back with completed
 * batchbuffers in a long time. The first time this is called we simply record
 * ACTHD. If ACTHD hasn't changed by the time the hangcheck timer elapses
 * again, we assume the chip is wedged and try to fix it.
 */
void i915_hangcheck_elapsed(unsigned long data)
{
        struct drm_device *dev = (struct drm_device *)data;
        drm_i915_private_t *dev_priv = dev->dev_private;
        uint32_t acthd;
       
        if (!IS_I965G(dev))
                acthd = I915_READ(ACTHD);
        else
                acthd = I915_READ(ACTHD_I965);

        /* If all work is done then ACTHD clearly hasn't advanced. */
        if (list_empty(&dev_priv->mm.request_list) ||
                       i915_seqno_passed(i915_get_gem_seqno(dev), i915_get_tail_request(dev)->seqno)) {
                dev_priv->hangcheck_count = 0;
                return;
        }

        if (dev_priv->last_acthd == acthd && dev_priv->hangcheck_count > 0) {
                DRM_ERROR("Hangcheck timer elapsed... GPU hung\n");
                i915_handle_error(dev, true);
                return;
        } 

        /* Reset timer case chip hangs without another request being added */
        mod_timer(&dev_priv->hangcheck_timer, jiffies + DRM_I915_HANGCHECK_PERIOD);

        if (acthd != dev_priv->last_acthd)
                dev_priv->hangcheck_count = 0;
        else
                dev_priv->hangcheck_count++;

        dev_priv->last_acthd = acthd;
}

/* drm_dma.h hooks
*/
static void igdng_irq_preinstall(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

        I915_WRITE(HWSTAM, 0xeffe);

        /* XXX hotplug from PCH */

        I915_WRITE(DEIMR, 0xffffffff);
        I915_WRITE(DEIER, 0x0);
        (void) I915_READ(DEIER);

        /* and GT */
        I915_WRITE(GTIMR, 0xffffffff);
        I915_WRITE(GTIER, 0x0);
        (void) I915_READ(GTIER);
}

static int igdng_irq_postinstall(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        /* enable kind of interrupts always enabled */

        u32 display_mask = DE_MASTER_IRQ_CONTROL /*| DE_PCH_EVENT */;
        u32 render_mask = GT_USER_INTERRUPT;

        dev_priv->irq_mask_reg = ~display_mask;
        dev_priv->de_irq_enable_reg = display_mask;

        /* should always can generate irq */
        I915_WRITE(DEIIR, I915_READ(DEIIR));
        I915_WRITE(DEIMR, dev_priv->irq_mask_reg);
        I915_WRITE(DEIER, dev_priv->de_irq_enable_reg);
        (void) I915_READ(DEIER);

        /* user interrupt should be enabled, but masked initial */
        dev_priv->gt_irq_mask_reg = 0xffffffff;
        dev_priv->gt_irq_enable_reg = render_mask;

        I915_WRITE(GTIIR, I915_READ(GTIIR));
        I915_WRITE(GTIMR, dev_priv->gt_irq_mask_reg);
        I915_WRITE(GTIER, dev_priv->gt_irq_enable_reg);
        (void) I915_READ(GTIER);

        return 0;
}

void i915_driver_irq_preinstall(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

        atomic_set(&dev_priv->irq_received, 0);

        INIT_WORK(&dev_priv->hotplug_work, i915_hotplug_work_func);
        INIT_WORK(&dev_priv->error_work, i915_error_work_func);

        if (IS_IGDNG(dev)) {
                igdng_irq_preinstall(dev);
                return;
        }

        if (I915_HAS_HOTPLUG(dev)) {
                I915_WRITE(PORT_HOTPLUG_EN, 0);
                I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
        }

        I915_WRITE(HWSTAM, 0xeffe);
        I915_WRITE(PIPEASTAT, 0);
        I915_WRITE(PIPEBSTAT, 0);
        I915_WRITE(IMR, 0xffffffff);
        I915_WRITE(IER, 0x0);
        (void) I915_READ(IER);
}

int i915_driver_irq_postinstall(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        u32 enable_mask = I915_INTERRUPT_ENABLE_FIX | I915_INTERRUPT_ENABLE_VAR;
        u32 error_mask;

        DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);

        dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B;

        if (IS_IGDNG(dev))
                return igdng_irq_postinstall(dev);

        /* Unmask the interrupts that we always want on. */
        dev_priv->irq_mask_reg = ~I915_INTERRUPT_ENABLE_FIX;

        dev_priv->pipestat[0] = 0;
        dev_priv->pipestat[1] = 0;

        if (I915_HAS_HOTPLUG(dev)) {
                u32 hotplug_en = I915_READ(PORT_HOTPLUG_EN);

                /* Leave other bits alone */
                hotplug_en |= HOTPLUG_EN_MASK;
                I915_WRITE(PORT_HOTPLUG_EN, hotplug_en);

                dev_priv->hotplug_supported_mask = CRT_HOTPLUG_INT_STATUS |
                        TV_HOTPLUG_INT_STATUS | SDVOC_HOTPLUG_INT_STATUS |
                        SDVOB_HOTPLUG_INT_STATUS;
                if (IS_G4X(dev)) {
                        dev_priv->hotplug_supported_mask |=
                                HDMIB_HOTPLUG_INT_STATUS |
                                HDMIC_HOTPLUG_INT_STATUS |
                                HDMID_HOTPLUG_INT_STATUS;
                }
                /* Enable in IER... */
                enable_mask |= I915_DISPLAY_PORT_INTERRUPT;
                /* and unmask in IMR */
                i915_enable_irq(dev_priv, I915_DISPLAY_PORT_INTERRUPT);
        }

        /*
         * Enable some error detection, note the instruction error mask
         * bit is reserved, so we leave it masked.
         */
        if (IS_G4X(dev)) {
                error_mask = ~(GM45_ERROR_PAGE_TABLE |
                               GM45_ERROR_MEM_PRIV |
                               GM45_ERROR_CP_PRIV |
                               I915_ERROR_MEMORY_REFRESH);
        } else {
                error_mask = ~(I915_ERROR_PAGE_TABLE |
                               I915_ERROR_MEMORY_REFRESH);
        }
        I915_WRITE(EMR, error_mask);

        /* Disable pipe interrupt enables, clear pending pipe status */
        I915_WRITE(PIPEASTAT, I915_READ(PIPEASTAT) & 0x8000ffff);
        I915_WRITE(PIPEBSTAT, I915_READ(PIPEBSTAT) & 0x8000ffff);
        /* Clear pending interrupt status */
        I915_WRITE(IIR, I915_READ(IIR));

        I915_WRITE(IER, enable_mask);
        I915_WRITE(IMR, dev_priv->irq_mask_reg);
        (void) I915_READ(IER);

        opregion_enable_asle(dev);

        return 0;
}

static void igdng_irq_uninstall(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        I915_WRITE(HWSTAM, 0xffffffff);

        I915_WRITE(DEIMR, 0xffffffff);
        I915_WRITE(DEIER, 0x0);
        I915_WRITE(DEIIR, I915_READ(DEIIR));

        I915_WRITE(GTIMR, 0xffffffff);
        I915_WRITE(GTIER, 0x0);
        I915_WRITE(GTIIR, I915_READ(GTIIR));
}

void i915_driver_irq_uninstall(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

        if (!dev_priv)
                return;

        dev_priv->vblank_pipe = 0;

        if (IS_IGDNG(dev)) {
                igdng_irq_uninstall(dev);
                return;
        }

        if (I915_HAS_HOTPLUG(dev)) {
                I915_WRITE(PORT_HOTPLUG_EN, 0);
                I915_WRITE(PORT_HOTPLUG_STAT, I915_READ(PORT_HOTPLUG_STAT));
        }

        I915_WRITE(HWSTAM, 0xffffffff);
        I915_WRITE(PIPEASTAT, 0);
        I915_WRITE(PIPEBSTAT, 0);
        I915_WRITE(IMR, 0xffffffff);
        I915_WRITE(IER, 0x0);

        I915_WRITE(PIPEASTAT, I915_READ(PIPEASTAT) & 0x8000ffff);
        I915_WRITE(PIPEBSTAT, I915_READ(PIPEBSTAT) & 0x8000ffff);
        I915_WRITE(IIR, I915_READ(IIR));
}