gpu: nvgpu: handle clk arb event posting in OS specific code

The mechanism of posting events to userspace is OS specific.
In linux this works through poll fd, wherein we can make use
of nvgpu_cond variables to poll and trigger the corresponding
wait_queue.

The post event functionality on QNX doesn't work on poll though.
It uses iofunc_notify_trigger to post the events to the calling
process. As such QNX can't work with nvgpu_cond's.

To overcome this issue, it is proposed to create OS specific
interface function for posting clk arb events. Linux can call
nvgpu_cond based implementation, which makes sense since these
are already initialized and poll'ed in Linux specific code only.
QNX can implement this interface to call iofunc_notify_*
functions, as per its need.

Jira VQRM-3741

Change-Id: I7d9f71dae2ae7f6a09cd56662003fd1b7e50324c
Signed-off-by: Sourab Gupta <sourabg@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1709656
GVS: Gerrit_Virtual_Submit
Reviewed-by: Alex Waterman <alexw@nvidia.com>
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

3 files changed, 10 insertions, 2 deletions

diff --git a/drivers/gpu/nvgpu/clk/clk_arb.c b/drivers/gpu/nvgpu/clk/clk_arb.c
index 368bacc2..67e452f0 100644
--- a/drivers/gpu/nvgpu/clk/clk_arb.c
+++ b/drivers/gpu/nvgpu/clk/clk_arb.c
@@ -697,7 +697,7 @@ static u32 nvgpu_clk_arb_notify(struct nvgpu_clk_dev *dev,
 
         if (poll_mask) {
                 nvgpu_atomic_set(&dev->poll_mask, poll_mask);
-                nvgpu_cond_broadcast_interruptible(&dev->readout_wq);
+                nvgpu_clk_arb_event_post_event(dev);
         }
 
         return new_alarms_reported;
@@ -1004,7 +1004,7 @@ exit_arb:
         nvgpu_list_for_each_entry_safe(dev, tmp, &arb->requests,
                         nvgpu_clk_dev, node) {
                 nvgpu_atomic_set(&dev->poll_mask, NVGPU_POLLIN | NVGPU_POLLRDNORM);
-                nvgpu_cond_signal_interruptible(&dev->readout_wq);
+                nvgpu_clk_arb_event_post_event(dev);
                 nvgpu_ref_put(&dev->refcount, nvgpu_clk_arb_free_fd);
                 nvgpu_list_del(&dev->node);
         }
diff --git a/drivers/gpu/nvgpu/common/linux/ioctl_clk_arb.c b/drivers/gpu/nvgpu/common/linux/ioctl_clk_arb.c
index 09d47722..a7c6a607 100644
--- a/drivers/gpu/nvgpu/common/linux/ioctl_clk_arb.c
+++ b/drivers/gpu/nvgpu/common/linux/ioctl_clk_arb.c
@@ -88,6 +88,11 @@ static unsigned int nvgpu_clk_arb_poll_dev(struct file *filp, poll_table *wait)
         return nvgpu_convert_poll_mask(nvgpu_atomic_xchg(&dev->poll_mask, 0));
 }
 
+void nvgpu_clk_arb_event_post_event(struct nvgpu_clk_dev *dev)
+{
+        nvgpu_cond_broadcast_interruptible(&dev->readout_wq);
+}
+
 static int nvgpu_clk_arb_release_event_dev(struct inode *inode,
                 struct file *filp)
 {
diff --git a/drivers/gpu/nvgpu/include/nvgpu/clk_arb.h b/drivers/gpu/nvgpu/include/nvgpu/clk_arb.h
index e91a0dad..0c9bbe06 100644
--- a/drivers/gpu/nvgpu/include/nvgpu/clk_arb.h
+++ b/drivers/gpu/nvgpu/include/nvgpu/clk_arb.h
@@ -349,6 +349,9 @@ int nvgpu_clk_notification_queue_alloc(struct gk20a *g,
 
 void nvgpu_clk_notification_queue_free(struct gk20a *g,
                 struct nvgpu_clk_notification_queue *queue);
+
+void nvgpu_clk_arb_event_post_event(struct nvgpu_clk_dev *dev);
+
 #ifdef CONFIG_DEBUG_FS
 int nvgpu_clk_arb_debugfs_init(struct gk20a *g);
 #endif