[PATCH v2 1/2] drm/msm: Add a GPU-wide wait queue

[Brian Ho]

This wait queue is signaled on all IRQs for a given GPU and will be
used as part of the new MSM_WAIT_IOVA ioctl so userspace can sleep
until the value at a given iova reaches a certain condition.

Signed-off-by: Brian Ho <brian at brkho.com>
---
 drivers/gpu/drm/msm/msm_gpu.c | 4 ++++
 drivers/gpu/drm/msm/msm_gpu.h | 3 +++
 2 files changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index a052364a5d74..d7310c1336e5 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -779,6 +779,8 @@ void msm_gpu_submit(struct msm_gpu *gpu, struct msm_gem_submit *submit,
 static irqreturn_t irq_handler(int irq, void *data)
 {
 	struct msm_gpu *gpu = data;
+	wake_up_all(&gpu->event);
+
 	return gpu->funcs->irq(gpu);
 }
 
@@ -871,6 +873,8 @@ int msm_gpu_init(struct drm_device *drm, struct platform_device *pdev,
 
 	spin_lock_init(&gpu->perf_lock);
 
+	init_waitqueue_head(&gpu->event);
+
 
 	/* Map registers: */
 	gpu->mmio = msm_ioremap(pdev, config->ioname, name);
diff --git a/drivers/gpu/drm/msm/msm_gpu.h b/drivers/gpu/drm/msm/msm_gpu.h
index ab8f0f9c9dc8..60562f065dbc 100644
--- a/drivers/gpu/drm/msm/msm_gpu.h
+++ b/drivers/gpu/drm/msm/msm_gpu.h
@@ -104,6 +104,9 @@ struct msm_gpu {
 
 	struct msm_gem_address_space *aspace;
 
+	/* GPU-wide wait queue that is signaled on all IRQs */
+	wait_queue_head_t event;
+
 	/* Power Control: */
 	struct regulator *gpu_reg, *gpu_cx;
 	struct clk_bulk_data *grp_clks;
-- 
2.25.0.rc1.283.g88dfdc4193-goog