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

#define USER_INT_FLAG (1<<1)
#define VSYNC_PIPEB_FLAG (1<<5)
#define VSYNC_PIPEA_FLAG (1<<7)

#define MAX_NOPID ((u32)~0)

/**
 * Emit blits for scheduled buffer swaps.
 *
 * This function will be called with the HW lock held.
 */
static void i915_vblank_tasklet(struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        unsigned long irqflags;
        struct list_head *list, *tmp, hits, *hit;
        int nhits, nrects, slice[2], upper[2], lower[2], i;
        unsigned counter[2] = { atomic_read(&dev->vbl_received),
                                atomic_read(&dev->vbl_received2) };
        struct drm_drawable_info *drw;
        drm_i915_sarea_t *sarea_priv = dev_priv->sarea_priv;
        u32 cpp = dev_priv->cpp;
        u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD |
                                XY_SRC_COPY_BLT_WRITE_ALPHA |
                                XY_SRC_COPY_BLT_WRITE_RGB)
                             : XY_SRC_COPY_BLT_CMD;
        u32 pitchropcpp = (sarea_priv->pitch * cpp) | (0xcc << 16) |
                          (cpp << 23) | (1 << 24);
        RING_LOCALS;

        DRM_DEBUG("\n");

        INIT_LIST_HEAD(&hits);

        nhits = nrects = 0;

        spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

        /* Find buffer swaps scheduled for this vertical blank */
        list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) {
                drm_i915_vbl_swap_t *vbl_swap =
                        list_entry(list, drm_i915_vbl_swap_t, head);

                if ((counter[vbl_swap->pipe] - vbl_swap->sequence) > (1<<23))
                        continue;

                list_del(list);
                dev_priv->swaps_pending--;

                spin_unlock(&dev_priv->swaps_lock);
                spin_lock(&dev->drw_lock);

                drw = drm_get_drawable_info(dev, vbl_swap->drw_id);

                if (!drw) {
                        spin_unlock(&dev->drw_lock);
                        drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
                        spin_lock(&dev_priv->swaps_lock);
                        continue;
                }

                list_for_each(hit, &hits) {
                        drm_i915_vbl_swap_t *swap_cmp =
                                list_entry(hit, drm_i915_vbl_swap_t, head);
                        struct drm_drawable_info *drw_cmp =
                                drm_get_drawable_info(dev, swap_cmp->drw_id);

                        if (drw_cmp &&
                            drw_cmp->rects[0].y1 > drw->rects[0].y1) {
                                list_add_tail(list, hit);
                                break;
                        }
                }

                spin_unlock(&dev->drw_lock);

                /* List of hits was empty, or we reached the end of it */
                if (hit == &hits)
                        list_add_tail(list, hits.prev);

                nhits++;

                spin_lock(&dev_priv->swaps_lock);
        }

        if (nhits == 0) {
                spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
                return;
        }

        spin_unlock(&dev_priv->swaps_lock);

        i915_kernel_lost_context(dev);

        BEGIN_LP_RING(6);

        OUT_RING(GFX_OP_DRAWRECT_INFO);
        OUT_RING(0);
        OUT_RING(0);
        OUT_RING(sarea_priv->width | sarea_priv->height << 16);
        OUT_RING(sarea_priv->width | sarea_priv->height << 16);
        OUT_RING(0);

        ADVANCE_LP_RING();

        sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT;

        upper[0] = upper[1] = 0;
        slice[0] = max(sarea_priv->pipeA_h / nhits, 1);
        slice[1] = max(sarea_priv->pipeB_h / nhits, 1);
        lower[0] = sarea_priv->pipeA_y + slice[0];
        lower[1] = sarea_priv->pipeB_y + slice[0];

        spin_lock(&dev->drw_lock);

        /* Emit blits for buffer swaps, partitioning both outputs into as many
         * slices as there are buffer swaps scheduled in order to avoid tearing
         * (based on the assumption that a single buffer swap would always
         * complete before scanout starts).
         */
        for (i = 0; i++ < nhits;
             upper[0] = lower[0], lower[0] += slice[0],
             upper[1] = lower[1], lower[1] += slice[1]) {
                if (i == nhits)
                        lower[0] = lower[1] = sarea_priv->height;

                list_for_each(hit, &hits) {
                        drm_i915_vbl_swap_t *swap_hit =
                                list_entry(hit, drm_i915_vbl_swap_t, head);
                        struct drm_clip_rect *rect;
                        int num_rects, pipe;
                        unsigned short top, bottom;

                        drw = drm_get_drawable_info(dev, swap_hit->drw_id);

                        if (!drw)
                                continue;

                        rect = drw->rects;
                        pipe = swap_hit->pipe;
                        top = upper[pipe];
                        bottom = lower[pipe];

                        for (num_rects = drw->num_rects; num_rects--; rect++) {
                                int y1 = max(rect->y1, top);
                                int y2 = min(rect->y2, bottom);

                                if (y1 >= y2)
                                        continue;

                                BEGIN_LP_RING(8);

                                OUT_RING(cmd);
                                OUT_RING(pitchropcpp);
                                OUT_RING((y1 << 16) | rect->x1);
                                OUT_RING((y2 << 16) | rect->x2);
                                OUT_RING(sarea_priv->front_offset);
                                OUT_RING((y1 << 16) | rect->x1);
                                OUT_RING(pitchropcpp & 0xffff);
                                OUT_RING(sarea_priv->back_offset);

                                ADVANCE_LP_RING();
                        }
                }
        }

        spin_unlock_irqrestore(&dev->drw_lock, irqflags);

        list_for_each_safe(hit, tmp, &hits) {
                drm_i915_vbl_swap_t *swap_hit =
                        list_entry(hit, drm_i915_vbl_swap_t, head);

                list_del(hit);

                drm_free(swap_hit, sizeof(*swap_hit), DRM_MEM_DRIVER);
        }
}

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;
        u16 temp;
        u32 pipea_stats, pipeb_stats;

        pipea_stats = I915_READ(I915REG_PIPEASTAT);
        pipeb_stats = I915_READ(I915REG_PIPEBSTAT);

        temp = I915_READ16(I915REG_INT_IDENTITY_R);

        temp &= (USER_INT_FLAG | VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG);

        DRM_DEBUG("%s flag=%08x\n", __FUNCTION__, temp);

        if (temp == 0)
                return IRQ_NONE;

        I915_WRITE16(I915REG_INT_IDENTITY_R, temp);
        (void) I915_READ16(I915REG_INT_IDENTITY_R);
        DRM_READMEMORYBARRIER();

        dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);

        if (temp & USER_INT_FLAG)
                DRM_WAKEUP(&dev_priv->irq_queue);

        if (temp & (VSYNC_PIPEA_FLAG | VSYNC_PIPEB_FLAG)) {
                int vblank_pipe = dev_priv->vblank_pipe;

                if ((vblank_pipe &
                     (DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B))
                    == (DRM_I915_VBLANK_PIPE_A | DRM_I915_VBLANK_PIPE_B)) {
                        if (temp & VSYNC_PIPEA_FLAG)
                                atomic_inc(&dev->vbl_received);
                        if (temp & VSYNC_PIPEB_FLAG)
                                atomic_inc(&dev->vbl_received2);
                } else if (((temp & VSYNC_PIPEA_FLAG) &&
                            (vblank_pipe & DRM_I915_VBLANK_PIPE_A)) ||
                           ((temp & VSYNC_PIPEB_FLAG) &&
                            (vblank_pipe & DRM_I915_VBLANK_PIPE_B)))
                        atomic_inc(&dev->vbl_received);

                DRM_WAKEUP(&dev->vbl_queue);
                drm_vbl_send_signals(dev);

                if (dev_priv->swaps_pending > 0)
                        drm_locked_tasklet(dev, i915_vblank_tasklet);
                I915_WRITE(I915REG_PIPEASTAT,
                        pipea_stats|I915_VBLANK_INTERRUPT_ENABLE|
                        I915_VBLANK_CLEAR);
                I915_WRITE(I915REG_PIPEBSTAT,
                        pipeb_stats|I915_VBLANK_INTERRUPT_ENABLE|
                        I915_VBLANK_CLEAR);
        }

        return IRQ_HANDLED;
}

static int i915_emit_irq(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        RING_LOCALS;

        i915_kernel_lost_context(dev);

        DRM_DEBUG("%s\n", __FUNCTION__);

        dev_priv->sarea_priv->last_enqueue = ++dev_priv->counter;

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

        BEGIN_LP_RING(6);
        OUT_RING(CMD_STORE_DWORD_IDX);
        OUT_RING(20);
        OUT_RING(dev_priv->counter);
        OUT_RING(0);
        OUT_RING(0);
        OUT_RING(GFX_OP_USER_INTERRUPT);
        ADVANCE_LP_RING();
        
        return dev_priv->counter;
}

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;
        int ret = 0;

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

        if (READ_BREADCRUMB(dev_priv) >= irq_nr)
                return 0;

        dev_priv->sarea_priv->perf_boxes |= I915_BOX_WAIT;

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

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

        dev_priv->sarea_priv->last_dispatch = READ_BREADCRUMB(dev_priv);
        return ret;
}

static int i915_driver_vblank_do_wait(struct drm_device *dev, unsigned int *sequence,
                                      atomic_t *counter)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        unsigned int cur_vblank;
        int ret = 0;

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

        DRM_WAIT_ON(ret, dev->vbl_queue, 3 * DRM_HZ,
                    (((cur_vblank = atomic_read(counter))
                        - *sequence) <= (1<<23)));
        
        *sequence = cur_vblank;

        return ret;
}


int i915_driver_vblank_wait(struct drm_device *dev, unsigned int *sequence)
{
        return i915_driver_vblank_do_wait(dev, sequence, &dev->vbl_received);
}

int i915_driver_vblank_wait2(struct drm_device *dev, unsigned int *sequence)
{
        return i915_driver_vblank_do_wait(dev, sequence, &dev->vbl_received2);
}

/* 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;

        LOCK_TEST_WITH_RETURN(dev, file_priv);

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

        result = i915_emit_irq(dev);

        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("%s called with no initialization\n", __FUNCTION__);
                return -EINVAL;
        }

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

static void i915_enable_interrupt (struct drm_device *dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        u16 flag;

        flag = 0;
        if (dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_A)
                flag |= VSYNC_PIPEA_FLAG;
        if (dev_priv->vblank_pipe & DRM_I915_VBLANK_PIPE_B)
                flag |= VSYNC_PIPEB_FLAG;

        I915_WRITE16(I915REG_INT_ENABLE_R, USER_INT_FLAG | flag);
}

/* 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;
        drm_i915_vblank_pipe_t *pipe = data;

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

        if (pipe->pipe & ~(DRM_I915_VBLANK_PIPE_A|DRM_I915_VBLANK_PIPE_B)) {
                DRM_ERROR("%s called with invalid pipe 0x%x\n", 
                          __FUNCTION__, pipe->pipe);
                return -EINVAL;
        }

        dev_priv->vblank_pipe = pipe->pipe;

        i915_enable_interrupt (dev);

        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;
        u16 flag;

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

        flag = I915_READ(I915REG_INT_ENABLE_R);
        pipe->pipe = 0;
        if (flag & VSYNC_PIPEA_FLAG)
                pipe->pipe |= DRM_I915_VBLANK_PIPE_A;
        if (flag & VSYNC_PIPEB_FLAG)
                pipe->pipe |= 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)
{
        drm_i915_private_t *dev_priv = dev->dev_private;
        drm_i915_vblank_swap_t *swap = data;
        drm_i915_vbl_swap_t *vbl_swap;
        unsigned int pipe, seqtype, curseq;
        unsigned long irqflags;
        struct list_head *list;

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

        if (dev_priv->sarea_priv->rotation) {
                DRM_DEBUG("Rotation not supported\n");
                return -EINVAL;
        }

        if (swap->seqtype & ~(_DRM_VBLANK_RELATIVE | _DRM_VBLANK_ABSOLUTE |
                             _DRM_VBLANK_SECONDARY | _DRM_VBLANK_NEXTONMISS)) {
                DRM_ERROR("Invalid sequence type 0x%x\n", swap->seqtype);
                return -EINVAL;
        }

        pipe = (swap->seqtype & _DRM_VBLANK_SECONDARY) ? 1 : 0;

        seqtype = swap->seqtype & (_DRM_VBLANK_RELATIVE | _DRM_VBLANK_ABSOLUTE);

        if (!(dev_priv->vblank_pipe & (1 << pipe))) {
                DRM_ERROR("Invalid pipe %d\n", pipe);
                return -EINVAL;
        }

        spin_lock_irqsave(&dev->drw_lock, irqflags);

        if (!drm_get_drawable_info(dev, swap->drawable)) {
                spin_unlock_irqrestore(&dev->drw_lock, irqflags);
                DRM_DEBUG("Invalid drawable ID %d\n", swap->drawable);
                return -EINVAL;
        }

        spin_unlock_irqrestore(&dev->drw_lock, irqflags);

        curseq = atomic_read(pipe ? &dev->vbl_received2 : &dev->vbl_received);

        if (seqtype == _DRM_VBLANK_RELATIVE)
                swap->sequence += curseq;

        if ((curseq - swap->sequence) <= (1<<23)) {
                if (swap->seqtype & _DRM_VBLANK_NEXTONMISS) {
                        swap->sequence = curseq + 1;
                } else {
                        DRM_DEBUG("Missed target sequence\n");
                        return -EINVAL;
                }
        }

        spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

        list_for_each(list, &dev_priv->vbl_swaps.head) {
                vbl_swap = list_entry(list, drm_i915_vbl_swap_t, head);

                if (vbl_swap->drw_id == swap->drawable &&
                    vbl_swap->pipe == pipe &&
                    vbl_swap->sequence == swap->sequence) {
                        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
                        DRM_DEBUG("Already scheduled\n");
                        return 0;
                }
        }

        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);

        if (dev_priv->swaps_pending >= 100) {
                DRM_DEBUG("Too many swaps queued\n");
                return -EBUSY;
        }

        vbl_swap = drm_calloc(1, sizeof(*vbl_swap), DRM_MEM_DRIVER);

        if (!vbl_swap) {
                DRM_ERROR("Failed to allocate memory to queue swap\n");
                return -ENOMEM;
        }

        DRM_DEBUG("\n");

        vbl_swap->drw_id = swap->drawable;
        vbl_swap->pipe = pipe;
        vbl_swap->sequence = swap->sequence;

        spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

        list_add_tail((struct list_head *)vbl_swap, &dev_priv->vbl_swaps.head);
        dev_priv->swaps_pending++;

        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);

        return 0;
}

/* drm_dma.h hooks
*/
void i915_driver_irq_preinstall(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

        I915_WRITE16(I915REG_HWSTAM, 0xfffe);
        I915_WRITE16(I915REG_INT_MASK_R, 0x0);
        I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);
}

void i915_driver_irq_postinstall(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;

        spin_lock_init(&dev_priv->swaps_lock);
        INIT_LIST_HEAD(&dev_priv->vbl_swaps.head);
        dev_priv->swaps_pending = 0;

        if (!dev_priv->vblank_pipe)
                dev_priv->vblank_pipe = DRM_I915_VBLANK_PIPE_A;
        i915_enable_interrupt(dev);
        DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
}

void i915_driver_irq_uninstall(struct drm_device * dev)
{
        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
        u16 temp;

        if (!dev_priv)
                return;

        I915_WRITE16(I915REG_HWSTAM, 0xffff);
        I915_WRITE16(I915REG_INT_MASK_R, 0xffff);
        I915_WRITE16(I915REG_INT_ENABLE_R, 0x0);

        temp = I915_READ16(I915REG_INT_IDENTITY_R);
        I915_WRITE16(I915REG_INT_IDENTITY_R, temp);
}