drm/amdkfd: Initialize only amdkfd's assigned pipelines

commit 1365aa6266fad0669487240af3f098593796172c upstream.

This patch fixes a bug in the initialization of the pipelines. The
init_pipelines() function was called with a constant value of 0 in the
first_pipe argument. This is an error because amdkfd doesn't handle pipe 0.

The correct way is to pass the value that get_first_pipe() returns as the
argument for first_pipe.

This bug appeared in 3.19 (first version with amdkfd) and it causes around 15%
drop in CPU performance of Kaveri (A10-7850).

v2: Don't set get_first_pipe() as inline because it calls BUG_ON()

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Tested-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
index 0fd592799d58dc6fdbd6c37bb5e826ed0f89cf9a..c80a8a31890d2ab17ca79ac62a04fecd3b488fc8 100644 (file)
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
@@ -56,9 +56,9 @@ static inline unsigned int get_pipes_num(struct device_queue_manager *dqm)
        return dqm->dev->shared_resources.compute_pipe_count;
 }
 
-static inline unsigned int get_first_pipe(struct device_queue_manager *dqm)
+unsigned int get_first_pipe(struct device_queue_manager *dqm)
 {
-       BUG_ON(!dqm);
+       BUG_ON(!dqm || !dqm->dev);
        return dqm->dev->shared_resources.first_compute_pipe;
 }
 
@@ -693,7 +693,7 @@ static int initialize_cpsch(struct device_queue_manager *dqm)
        INIT_LIST_HEAD(&dqm->queues);
        dqm->queue_count = dqm->processes_count = 0;
        dqm->active_runlist = false;
-       retval = init_pipelines(dqm, get_pipes_num(dqm), 0);
+       retval = init_pipelines(dqm, get_pipes_num(dqm), get_first_pipe(dqm));
        if (retval != 0)
                goto fail_init_pipelines;