i915: Remove racy delayed vblank swap ioctl. (bd95e0a4) · Commits · 戴 / test

drivers/gpu/drm/i915/i915_drv.h

+0 −15

Original line number	Diff line number	Diff line
		@@ -88,13 +88,6 @@ struct mem_block {
		struct drm_file file_priv; / NULL: free, -1: heap, other: real files */
		};

		typedef struct _drm_i915_vbl_swap {
		struct list_head head;
		drm_drawable_t drw_id;
		unsigned int pipe;
		unsigned int sequence;
		} drm_i915_vbl_swap_t;

		struct opregion_header;
		struct opregion_acpi;
		struct opregion_swsci;
		@@ -146,10 +139,6 @@ typedef struct drm_i915_private {
		unsigned int sr01, adpa, ppcr, dvob, dvoc, lvds;
		int vblank_pipe;

		spinlock_t swaps_lock;
		drm_i915_vbl_swap_t vbl_swaps;
		unsigned int swaps_pending;

		struct intel_opregion opregion;

		/* Register state */
		@@ -242,9 +231,6 @@ typedef struct drm_i915_private {
		u8 saveDACDATA[2563]; / 256 3-byte colors */
		u8 saveCR[37];

		/** Work task for vblank-related ring access */
		struct work_struct vblank_work;

		struct {
		struct drm_mm gtt_space;

		@@ -445,7 +431,6 @@ extern int i915_irq_wait(struct drm_device dev, void data,
		void i915_user_irq_get(struct drm_device *dev);
		void i915_user_irq_put(struct drm_device *dev);

		extern void i915_vblank_work_handler(struct work_struct *work);
		extern irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS);
		extern void i915_driver_irq_preinstall(struct drm_device * dev);
		extern int i915_driver_irq_postinstall(struct drm_device *dev);

drivers/gpu/drm/i915/i915_irq.c

+14 −363

Original line number	Diff line number	Diff line
		@@ -80,211 +80,6 @@ i915_pipe_enabled(struct drm_device *dev, int pipe)
		return 0;
		}

		/**
		* Emit blits for scheduled buffer swaps.
		*
		* This function will be called with the HW lock held.
		* Because this function must grab the ring mutex (dev->struct_mutex),
		* it can no longer run at soft irq time. We'll fix this when we do
		* the DRI2 swap buffer work.
		*/
		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];
		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 src_pitch = sarea_priv->pitch * cpp;
		u32 dst_pitch = sarea_priv->pitch * cpp;
		u32 ropcpp = (0xcc << 16) \| ((cpp - 1) << 24);
		RING_LOCALS;

		mutex_lock(&dev->struct_mutex);

		if (IS_I965G(dev) && sarea_priv->front_tiled) {
		cmd \|= XY_SRC_COPY_BLT_DST_TILED;
		dst_pitch >>= 2;
		}
		if (IS_I965G(dev) && sarea_priv->back_tiled) {
		cmd \|= XY_SRC_COPY_BLT_SRC_TILED;
		src_pitch >>= 2;
		}

		counter[0] = drm_vblank_count(dev, 0);
		counter[1] = drm_vblank_count(dev, 1);

		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);
		int pipe = vbl_swap->pipe;

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

		list_del(list);
		dev_priv->swaps_pending--;
		drm_vblank_put(dev, pipe);

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

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

		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);

		/* Make sure both drawables are still
		* around and have some rectangles before
		* we look inside to order them for the
		* blts below.
		*/
		if (drw_cmp && drw_cmp->num_rects > 0 &&
		drw && drw->num_rects > 0 &&
		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);
		mutex_unlock(&dev->struct_mutex);
		return;
		}

		spin_unlock(&dev_priv->swaps_lock);

		i915_kernel_lost_context(dev);

		if (IS_I965G(dev)) {
		BEGIN_LP_RING(4);

		OUT_RING(GFX_OP_DRAWRECT_INFO_I965);
		OUT_RING(0);
		OUT_RING(((sarea_priv->width - 1) & 0xffff) \| ((sarea_priv->height - 1) << 16));
		OUT_RING(0);
		ADVANCE_LP_RING();
		} else {
		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);

		/* The drawable may have been destroyed since
		* the vblank swap was queued
		*/
		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(ropcpp \| dst_pitch);
		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(src_pitch);
		OUT_RING(sarea_priv->back_offset);

		ADVANCE_LP_RING();
		}
		}
		}

		spin_unlock_irqrestore(&dev->drw_lock, irqflags);
		mutex_unlock(&dev->struct_mutex);

		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);
		}
		}

		/* Called from drm generic code, passed a 'crtc', which
		* we use as a pipe index
		*/
		@@ -322,40 +117,6 @@ u32 i915_get_vblank_counter(struct drm_device *dev, int pipe)
		return count;
		}

		void
		i915_vblank_work_handler(struct work_struct *work)
		{
		drm_i915_private_t *dev_priv = container_of(work, drm_i915_private_t,
		vblank_work);
		struct drm_device *dev = dev_priv->dev;
		unsigned long irqflags;

		if (dev->lock.hw_lock == NULL) {
		i915_vblank_tasklet(dev);
		return;
		}

		spin_lock_irqsave(&dev->tasklet_lock, irqflags);
		dev->locked_tasklet_func = i915_vblank_tasklet;
		spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);

		/* Try to get the lock now, if this fails, the lock
		* holder will execute the tasklet during unlock
		*/
		if (!drm_lock_take(&dev->lock, DRM_KERNEL_CONTEXT))
		return;

		dev->lock.lock_time = jiffies;
		atomic_inc(&dev->counts[_DRM_STAT_LOCKS]);

		spin_lock_irqsave(&dev->tasklet_lock, irqflags);
		dev->locked_tasklet_func = NULL;
		spin_unlock_irqrestore(&dev->tasklet_lock, irqflags);

		i915_vblank_tasklet(dev);
		drm_lock_free(&dev->lock, DRM_KERNEL_CONTEXT);
		}

		irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
		{
		struct drm_device dev = (struct drm_device ) arg;
		@@ -433,9 +194,6 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
		if (iir & I915_ASLE_INTERRUPT)
		opregion_asle_intr(dev);

		if (vblank && dev_priv->swaps_pending > 0)
		schedule_work(&dev_priv->vblank_work);

		return IRQ_HANDLED;
		}

		@@ -696,124 +454,22 @@ int i915_vblank_pipe_get(struct drm_device dev, void data,
		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, vbl_old;
		unsigned int pipe, seqtype, curseq;
		unsigned long irqflags;
		struct list_head *list;
		int ret;

		if (!dev_priv \|\| !dev_priv->sarea_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);

		/*
		* We take the ref here and put it when the swap actually completes
		* in the tasklet.
		/* 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.
		*/
		ret = drm_vblank_get(dev, pipe);
		if (ret)
		return ret;
		curseq = drm_vblank_count(dev, pipe);

		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");
		drm_vblank_put(dev, pipe);
		return -EINVAL;
		}
		}

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

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

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

		spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);

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

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

		if (dev_priv->swaps_pending >= 10) {
		DRM_DEBUG("Too many swaps queued\n");
		DRM_DEBUG(" pipe 0: %d pipe 1: %d\n",
		drm_vblank_count(dev, 0),
		drm_vblank_count(dev, 1));

		list_for_each(list, &dev_priv->vbl_swaps.head) {
		vbl_old = list_entry(list, drm_i915_vbl_swap_t, head);
		DRM_DEBUG("\tdrw %x pipe %d seq %x\n",
		vbl_old->drw_id, vbl_old->pipe,
		vbl_old->sequence);
		}
		spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
		drm_vblank_put(dev, pipe);
		drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
		return -EBUSY;
		}

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

		spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);

		return 0;
		}

		/* drm_dma.h hooks
		*/
		@@ -831,11 +487,6 @@ int i915_driver_irq_postinstall(struct drm_device *dev)
		drm_i915_private_t dev_priv = (drm_i915_private_t ) dev->dev_private;
		int ret, num_pipes = 2;

		spin_lock_init(&dev_priv->swaps_lock);
		INIT_LIST_HEAD(&dev_priv->vbl_swaps.head);
		INIT_WORK(&dev_priv->vblank_work, i915_vblank_work_handler);
		dev_priv->swaps_pending = 0;

		/* Set initial unmasked IRQs to just the selected vblank pipes. */
		dev_priv->irq_mask_reg = ~0;

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