drm/nouveau: Implement the pageflip ioctl.

nv0x-nv4x should be mostly fine, nv50 doesn't work yet.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 180 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/nouveau_display.c b/drivers/gpu/drm/nouveau/nouveau_display.c
index f8987bcb7f51..505c6bfb4d75 100644
--- a/drivers/gpu/drm/nouveau/nouveau_display.c
+++ b/drivers/gpu/drm/nouveau/nouveau_display.c
@@ -30,6 +30,8 @@
 #include "nouveau_fb.h"
 #include "nouveau_fbcon.h"
 #include "nouveau_hw.h"
+#include "nouveau_crtc.h"
+#include "nouveau_dma.h"
 
 static void
 nouveau_user_framebuffer_destroy(struct drm_framebuffer *drm_fb)
@@ -131,3 +133,181 @@ nouveau_vblank_disable(struct drm_device *dev, int crtc)
         else
                 NVWriteCRTC(dev, crtc, NV_PCRTC_INTR_EN_0, 0);
 }
+
+static int
+nouveau_page_flip_reserve(struct nouveau_bo *old_bo,
+                          struct nouveau_bo *new_bo)
+{
+        int ret;
+
+        ret = nouveau_bo_pin(new_bo, TTM_PL_FLAG_VRAM);
+        if (ret)
+                return ret;
+
+        ret = ttm_bo_reserve(&new_bo->bo, false, false, false, 0);
+        if (ret)
+                goto fail;
+
+        ret = ttm_bo_reserve(&old_bo->bo, false, false, false, 0);
+        if (ret)
+                goto fail_unreserve;
+
+        return 0;
+
+fail_unreserve:
+        ttm_bo_unreserve(&new_bo->bo);
+fail:
+        nouveau_bo_unpin(new_bo);
+        return ret;
+}
+
+static void
+nouveau_page_flip_unreserve(struct nouveau_bo *old_bo,
+                            struct nouveau_bo *new_bo,
+                            struct nouveau_fence *fence)
+{
+        nouveau_bo_fence(new_bo, fence);
+        ttm_bo_unreserve(&new_bo->bo);
+
+        nouveau_bo_fence(old_bo, fence);
+        ttm_bo_unreserve(&old_bo->bo);
+
+        nouveau_bo_unpin(old_bo);
+}
+
+static int
+nouveau_page_flip_emit(struct nouveau_channel *chan,
+                       struct nouveau_bo *old_bo,
+                       struct nouveau_bo *new_bo,
+                       struct nouveau_page_flip_state *s,
+                       struct nouveau_fence **pfence)
+{
+        struct drm_device *dev = chan->dev;
+        unsigned long flags;
+        int ret;
+
+        /* Queue it to the pending list */
+        spin_lock_irqsave(&dev->event_lock, flags);
+        list_add_tail(&s->head, &chan->nvsw.flip);
+        spin_unlock_irqrestore(&dev->event_lock, flags);
+
+        /* Synchronize with the old framebuffer */
+        ret = nouveau_fence_sync(old_bo->bo.sync_obj, chan);
+        if (ret)
+                goto fail;
+
+        /* Emit the pageflip */
+        ret = RING_SPACE(chan, 2);
+        if (ret)
+                goto fail;
+
+        BEGIN_RING(chan, NvSubSw, NV_SW_PAGE_FLIP, 1);
+        OUT_RING(chan, 0);
+        FIRE_RING(chan);
+
+        ret = nouveau_fence_new(chan, pfence, true);
+        if (ret)
+                goto fail;
+
+        return 0;
+fail:
+        spin_lock_irqsave(&dev->event_lock, flags);
+        list_del(&s->head);
+        spin_unlock_irqrestore(&dev->event_lock, flags);
+        return ret;
+}
+
+int
+nouveau_crtc_page_flip(struct drm_crtc *crtc, struct drm_framebuffer *fb,
+                       struct drm_pending_vblank_event *event)
+{
+        struct drm_device *dev = crtc->dev;
+        struct drm_nouveau_private *dev_priv = dev->dev_private;
+        struct nouveau_bo *old_bo = nouveau_framebuffer(crtc->fb)->nvbo;
+        struct nouveau_bo *new_bo = nouveau_framebuffer(fb)->nvbo;
+        struct nouveau_page_flip_state *s;
+        struct nouveau_channel *chan;
+        struct nouveau_fence *fence;
+        int ret;
+
+        if (dev_priv->engine.graph.accel_blocked)
+                return -ENODEV;
+
+        s = kzalloc(sizeof(*s), GFP_KERNEL);
+        if (!s)
+                return -ENOMEM;
+
+        /* Don't let the buffers go away while we flip */
+        ret = nouveau_page_flip_reserve(old_bo, new_bo);
+        if (ret)
+                goto fail_free;
+
+        /* Initialize a page flip struct */
+        *s = (struct nouveau_page_flip_state)
+                { { }, s->event, nouveau_crtc(crtc)->index,
+                  fb->bits_per_pixel, fb->pitch, crtc->x, crtc->y,
+                  new_bo->bo.offset };
+
+        /* Choose the channel the flip will be handled in */
+        chan = nouveau_fence_channel(new_bo->bo.sync_obj);
+        if (!chan)
+                chan = nouveau_channel_get_unlocked(dev_priv->channel);
+        mutex_lock(&chan->mutex);
+
+        /* Emit a page flip */
+        ret = nouveau_page_flip_emit(chan, old_bo, new_bo, s, &fence);
+        nouveau_channel_put(&chan);
+        if (ret)
+                goto fail_unreserve;
+
+        /* Update the crtc struct and cleanup */
+        crtc->fb = fb;
+
+        nouveau_page_flip_unreserve(old_bo, new_bo, fence);
+        nouveau_fence_unref(&fence);
+        return 0;
+
+fail_unreserve:
+        nouveau_page_flip_unreserve(old_bo, new_bo, NULL);
+fail_free:
+        kfree(s);
+        return ret;
+}
+
+int
+nouveau_finish_page_flip(struct nouveau_channel *chan,
+                         struct nouveau_page_flip_state *ps)
+{
+        struct drm_device *dev = chan->dev;
+        struct nouveau_page_flip_state *s;
+        unsigned long flags;
+
+        spin_lock_irqsave(&dev->event_lock, flags);
+
+        if (list_empty(&chan->nvsw.flip)) {
+                NV_ERROR(dev, "Unexpected pageflip in channel %d.\n", chan->id);
+                spin_unlock_irqrestore(&dev->event_lock, flags);
+                return -EINVAL;
+        }
+
+        s = list_first_entry(&chan->nvsw.flip,
+                             struct nouveau_page_flip_state, head);
+        if (s->event) {
+                struct drm_pending_vblank_event *e = s->event;
+                struct timeval now;
+
+                do_gettimeofday(&now);
+                e->event.sequence = 0;
+                e->event.tv_sec = now.tv_sec;
+                e->event.tv_usec = now.tv_usec;
+                list_add_tail(&e->base.link, &e->base.file_priv->event_list);
+                wake_up_interruptible(&e->base.file_priv->event_wait);
+        }
+
+        list_del(&s->head);
+        *ps = *s;
+        kfree(s);
+
+        spin_unlock_irqrestore(&dev->event_lock, flags);
+        return 0;
+}