[PATCH RFC tip/core/rcu 3/4] drivers/gpu/drm/amd: Dynamically allocate kfd_processes_srcu

[Paul E. McKenney]

Having DEFINE_SRCU() or DEFINE_STATIC_SRCU() in a loadable module
requires that the size of the reserved region be increased, which is
not something we really want to be doing.  This commit therefore removes
the DEFINE_STATIC_SRCU() from drivers/gpu/drm/amd/amdkfd/kfd_process.c in
favor of defining kfd_processes_srcu as a simple srcu_struct, initializing
it in amdgpu_amdkfd_init(), and cleaning it up in amdgpu_amdkfd_fini().

Reported-by: kbuild test robot <lkp at intel.com>
Signed-off-by: Paul E. McKenney <paulmck at linux.ibm.com>
Tested-by: kbuild test robot <lkp at intel.com>
Cc: Oded Gabbay <oded.gabbay at gmail.com>
Cc: Alex Deucher <alexander.deucher at amd.com>
Cc: "Christian König" <christian.koenig at amd.com
Cc: "David (ChunMing) Zhou" <David1.Zhou at amd.com>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Tejun Heo <tj at kernel.org>
Cc: <dri-devel at lists.freedesktop.org>
Cc: <amd-gfx at lists.freedesktop.org>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 5 +++++
 drivers/gpu/drm/amd/amdkfd/kfd_process.c   | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
index fe1d7368c1e6..eadb20dee867 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
@@ -28,6 +28,8 @@
 #include <linux/module.h>
 #include <linux/dma-buf.h>
 
+extern struct srcu_struct kfd_processes_srcu;
+
 static const unsigned int compute_vmid_bitmap = 0xFF00;
 
 /* Total memory size in system memory and all GPU VRAM. Used to
@@ -40,6 +42,8 @@ int amdgpu_amdkfd_init(void)
 	struct sysinfo si;
 	int ret;
 
+	ret = init_srcu_struct(&kfd_processes_srcu);
+	WARN_ON(ret);
 	si_meminfo(&si);
 	amdgpu_amdkfd_total_mem_size = si.totalram - si.totalhigh;
 	amdgpu_amdkfd_total_mem_size *= si.mem_unit;
@@ -57,6 +61,7 @@ int amdgpu_amdkfd_init(void)
 void amdgpu_amdkfd_fini(void)
 {
 	kgd2kfd_exit();
+	cleanup_srcu_struct(&kfd_processes_srcu);
 }
 
 void amdgpu_amdkfd_device_probe(struct amdgpu_device *adev)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index 4bdae78bab8e..98b694068b8a 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -47,7 +47,7 @@ struct mm_struct;
 DEFINE_HASHTABLE(kfd_processes_table, KFD_PROCESS_TABLE_SIZE);
 static DEFINE_MUTEX(kfd_processes_mutex);
 
-DEFINE_SRCU(kfd_processes_srcu);
+struct srcu_struct kfd_processes_srcu;
 
 /* For process termination handling */
 static struct workqueue_struct *kfd_process_wq;
-- 
2.17.1