v3dv: Add a condition variable for queries

In order to properly wait for a query to be complete, we need to first
wait for the end query job to flush through on the queue.  Since query
end is always handled on the CPU, we can do this with a condition
variable.  The 2s timeout is taken from ANV.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Reviewed-by: Iago Toral Quiroga <itoral@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15704>

src/broadcom/vulkan/v3dv_queue.c

@@ -180,6 +180,8 @@ handle_reset_query_cpu_job(struct v3dv_job *job)
 static VkResult
 handle_end_query_cpu_job(struct v3dv_job *job)
 {
+   mtx_lock(&job->device->query_mutex);
+
    struct v3dv_end_query_cpu_job_info *info = &job->cpu.query_end;
    for (uint32_t i = 0; i < info->count; i++) {
       assert(info->query + i < info->pool->query_count);
@@ -187,6 +189,9 @@ handle_end_query_cpu_job(struct v3dv_job *job)
       query->maybe_available = true;
    }
 
+   cnd_broadcast(&job->device->query_ended);
+   mtx_unlock(&job->device->query_mutex);
+
    return VK_SUCCESS;
 }
 
@@ -546,6 +551,8 @@ handle_timestamp_query_cpu_job(struct v3dv_job *job)
    /* Wait for completion of all work queued before the timestamp query */
    v3dv_QueueWaitIdle(v3dv_queue_to_handle(&job->device->queue));
 
+   mtx_lock(&job->device->query_mutex);
+
    /* Compute timestamp */
    struct timespec t;
    clock_gettime(CLOCK_MONOTONIC, &t);
@@ -558,6 +565,9 @@ handle_timestamp_query_cpu_job(struct v3dv_job *job)
          query->value = t.tv_sec * 1000000000ull + t.tv_nsec;
    }
 
+   cnd_broadcast(&job->device->query_ended);
+   mtx_unlock(&job->device->query_mutex);
+
    return VK_SUCCESS;
 }