From: Paulo Zanoni paulo.r.zanoni@intel.com
The drivers need a way to schedule functions to be ran after a certain number of vblanks. The i915.ko driver has plenty of examples where this could be used, such as for unpinning buffers after a modeset. Since the vblank wait IOCTL does basically what we want, but for the user space, in this patch we add a new list of vblank events (dev->vblank_kernel_list) and handle it exactly like we handle the user space events.
Signed-off-by: Paulo Zanoni paulo.r.zanoni@intel.com --- drivers/gpu/drm/drm_drv.c | 1 + drivers/gpu/drm/drm_irq.c | 106 ++++++++++++++++++++++++++++++++++-- drivers/gpu/drm/i915/i915_debugfs.c | 81 +++++++++++++++++++++++++++ include/drm/drmP.h | 22 ++++++++ 4 files changed, 206 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 2e5c7d9..b5ae6c8 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -557,6 +557,7 @@ struct drm_device *drm_dev_alloc(struct drm_driver *driver, INIT_LIST_HEAD(&dev->vmalist); INIT_LIST_HEAD(&dev->maplist); INIT_LIST_HEAD(&dev->vblank_event_list); + INIT_LIST_HEAD(&dev->vblank_kernel_list);
spin_lock_init(&dev->buf_lock); spin_lock_init(&dev->event_lock); diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 0e47df4..6e04035 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -1107,6 +1107,13 @@ void drm_crtc_wait_one_vblank(struct drm_crtc *crtc) } EXPORT_SYMBOL(drm_crtc_wait_one_vblank);
+static void send_kernel_vblank_event(struct drm_kernel_vblank_item *item) +{ + if (item->callback_from_work) + schedule_work(&item->work); + else + item->callback(item); +} /** * drm_vblank_off - disable vblank events on a CRTC * @dev: DRM device @@ -1124,7 +1131,8 @@ EXPORT_SYMBOL(drm_crtc_wait_one_vblank); void drm_vblank_off(struct drm_device *dev, int crtc) { struct drm_vblank_crtc *vblank = &dev->vblank[crtc]; - struct drm_pending_vblank_event *e, *t; + struct drm_pending_vblank_event *e, *et; + struct drm_kernel_vblank_item *i, *it; struct timeval now; unsigned long irqflags; unsigned int seq; @@ -1151,7 +1159,7 @@ void drm_vblank_off(struct drm_device *dev, int crtc) /* Send any queued vblank events, lest the natives grow disquiet */ seq = drm_vblank_count_and_time(dev, crtc, &now);
- list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { + list_for_each_entry_safe(e, et, &dev->vblank_event_list, base.link) { if (e->pipe != crtc) continue; DRM_DEBUG("Sending premature vblank event on disable: \ @@ -1161,6 +1169,21 @@ void drm_vblank_off(struct drm_device *dev, int crtc) drm_vblank_put(dev, e->pipe); send_vblank_event(dev, e, seq, &now); } + + list_for_each_entry_safe(i, it, &dev->vblank_kernel_list, link) { + int pipe = drm_crtc_index(i->crtc); + + if (pipe != crtc) + continue; + + DRM_DEBUG("Sending premature kernel vblank event on disable: \ + wanted %d, current %d\n", + i->target_seq, seq); + i->premature = true; + list_del(&i->link); + drm_vblank_put(dev, pipe); + send_kernel_vblank_event(i); + } spin_unlock_irqrestore(&dev->event_lock, irqflags); } EXPORT_SYMBOL(drm_vblank_off); @@ -1560,9 +1583,68 @@ done: return ret; }
+static void drm_kernel_vblank_work_func(struct work_struct *work) +{ + struct drm_kernel_vblank_item *item = + container_of(work, struct drm_kernel_vblank_item, work); + + item->callback(item); +} + +int drm_wait_vblank_kernel(struct drm_kernel_vblank_item *item) +{ + struct drm_crtc *crtc = item->crtc; + struct drm_device *dev = crtc->dev; + int pipe = drm_crtc_index(crtc); + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned int seq; + unsigned long irqflags; + int ret = 0; + + if (!dev->irq_enabled) + return -EINVAL; + + if (item->callback_from_work) + INIT_WORK(&item->work, drm_kernel_vblank_work_func); + + ret = drm_vblank_get(dev, pipe); + if (ret) { + DRM_DEBUG("failed to acquire vblank counter, %d\n", ret); + return ret; + } + + seq = drm_vblank_count(dev, pipe); + if (!item->absolute) + item->target_seq += seq; + + spin_lock_irqsave(&dev->event_lock, irqflags); + + if (!vblank->enabled) { + ret = -EINVAL; + goto out; + } + + if (seq - item->target_seq <= (1 << 23)) { + drm_vblank_put(dev, pipe); + send_kernel_vblank_event(item); + } else { + list_add_tail(&item->link, &dev->vblank_kernel_list); + } + + spin_unlock_irqrestore(&dev->event_lock, irqflags); + return 0; + +out: + spin_unlock_irqrestore(&dev->event_lock, irqflags); + drm_vblank_put(dev, pipe); + return ret; +} +EXPORT_SYMBOL(drm_wait_vblank_kernel); + static void drm_handle_vblank_events(struct drm_device *dev, int crtc) { - struct drm_pending_vblank_event *e, *t; + struct drm_pending_vblank_event *e, *et; + struct drm_kernel_vblank_item *i, *it; struct timeval now; unsigned int seq;
@@ -1570,7 +1652,7 @@ static void drm_handle_vblank_events(struct drm_device *dev, int crtc)
seq = drm_vblank_count_and_time(dev, crtc, &now);
- list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { + list_for_each_entry_safe(e, et, &dev->vblank_event_list, base.link) { if (e->pipe != crtc) continue; if ((seq - e->event.sequence) > (1<<23)) @@ -1584,6 +1666,22 @@ static void drm_handle_vblank_events(struct drm_device *dev, int crtc) send_vblank_event(dev, e, seq, &now); }
+ list_for_each_entry_safe(i, it, &dev->vblank_kernel_list, link) { + int pipe = drm_crtc_index(i->crtc); + + if (pipe != crtc) + continue; + if ((seq - i->target_seq) > (1<<23)) + continue; + + DRM_DEBUG("kernel vblank event on %d, current %d\n", + i->target_seq, seq); + + list_del(&i->link); + drm_vblank_put(dev, pipe); + send_kernel_vblank_event(i); + } + trace_drm_vblank_event(crtc, seq); }
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c index 319da61..e705976 100644 --- a/drivers/gpu/drm/i915/i915_debugfs.c +++ b/drivers/gpu/drm/i915/i915_debugfs.c @@ -2715,6 +2715,86 @@ static int i915_ddb_info(struct seq_file *m, void *unused) return 0; }
+struct vblank_data { + int eight; + const char *message; + struct drm_kernel_vblank_item item; +}; + +static void vblank_callback(struct drm_kernel_vblank_item *item) +{ + struct vblank_data *data = container_of(item, struct vblank_data, item); + + WARN_ON(data->eight != 8); + WARN_ON(item->callback_from_work != drm_can_sleep()); + DRM_DEBUG_KMS("vblank callback, premature: %s, message: %s\n", + yesno(item->premature), data->message); + + kfree(data); +} + +static int i915_vblank_queue_test_new(struct seq_file *m, void *unused) +{ + struct drm_info_node *node = m->private; + struct drm_device *dev = node->minor->dev; + struct intel_crtc *crtc = NULL; + int ret = 0; + struct vblank_data *data1, *data2; + + for_each_intel_crtc(dev, crtc) + if (crtc->pipe == PIPE_A) + break; + if (WARN_ON(!crtc)) + return -EINVAL; + + data1 = kzalloc(sizeof *data1, GFP_KERNEL); + if (!data1) + return -ENOMEM; + + data2 = kzalloc(sizeof *data2, GFP_KERNEL); + if (!data2) { + kfree(data1); + return -ENOMEM; + } + + data1->message = "hello world (atomic)"; + data1->eight = 8; + data1->item.crtc = &crtc->base; + data1->item.target_seq = 60; + data1->item.absolute = false; + data1->item.callback = vblank_callback; + data1->item.callback_from_work = false; + + data2->message = "hello world (work)"; + data2->eight = 8; + data2->item.crtc = &crtc->base; + data2->item.target_seq = 60; + data2->item.absolute = false; + data2->item.callback = vblank_callback; + data2->item.callback_from_work = true; + + DRM_DEBUG_KMS("scheduling 60 vblanks (no work)\n"); + ret = drm_wait_vblank_kernel(&data1->item); + if (ret) { + DRM_DEBUG_KMS("vblank schedule error: %d\n", ret); + kfree(data1); + kfree(data2); + return ret; + } + DRM_DEBUG_KMS("vblanks scheduled\n"); + + DRM_DEBUG_KMS("scheduling 60 vblanks (with work)\n"); + ret = drm_wait_vblank_kernel(&data2->item); + if (ret) { + DRM_DEBUG_KMS("vblank schedule error: %d\n", ret); + kfree(data2); + return ret; + } + DRM_DEBUG_KMS("vblanks scheduled\n"); + + return 0; +} + struct pipe_crc_info { const char *name; struct drm_device *dev; @@ -4289,6 +4369,7 @@ static const struct drm_info_list i915_debugfs_list[] = { {"i915_dp_mst_info", i915_dp_mst_info, 0}, {"i915_wa_registers", i915_wa_registers, 0}, {"i915_ddb_info", i915_ddb_info, 0}, + {"i915_vblank_queue_test_new", i915_vblank_queue_test_new, 0}, }; #define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)
diff --git a/include/drm/drmP.h b/include/drm/drmP.h index be776fb..295d0e0 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -667,6 +667,26 @@ struct drm_pending_vblank_event { struct drm_event_vblank event; };
+struct drm_kernel_vblank_item { + /* Internal members, set by drm.ko. */ + struct list_head link; + struct work_struct work; + + /* Parameters: set by the caller of drm_wait_vblank_kernel(). */ + struct drm_crtc *crtc; + + int target_seq; + bool absolute; /* Tells if target_seq is a relative offset to the + * current vblank count, or just an absolute value. */ + + void (*callback)(struct drm_kernel_vblank_item *item); + + bool callback_from_work; + + /* Output: to be used by the callback function. */ + bool premature; +}; + struct drm_vblank_crtc { struct drm_device *dev; /* pointer to the drm_device */ wait_queue_head_t queue; /**< VBLANK wait queue */ @@ -784,6 +804,7 @@ struct drm_device { * List of events */ struct list_head vblank_event_list; + struct list_head vblank_kernel_list; spinlock_t event_lock;
/*@} */ @@ -900,6 +921,7 @@ extern int drm_irq_uninstall(struct drm_device *dev); extern int drm_vblank_init(struct drm_device *dev, int num_crtcs); extern int drm_wait_vblank(struct drm_device *dev, void *data, struct drm_file *filp); +extern int drm_wait_vblank_kernel(struct drm_kernel_vblank_item *item); extern u32 drm_vblank_count(struct drm_device *dev, int crtc); extern u32 drm_vblank_count_and_time(struct drm_device *dev, int crtc, struct timeval *vblanktime);