[PATCH v3] drm/amdkfd: Fix stack size in 'amdgpu_amdkfd_unmap_hiq'

[Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>]

Allocate large local variable on heap to avoid exceeding the
stack size:
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c: In function ‘amdgpu_amdkfd_unmap_hiq’:
drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c:868:1: warning: the frame size of 1280 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Suggested-by: Guchun Chen <guchun.chen@xxxxxxx>
Cc: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@xxxxxxx>
---

v3:
 - free ring_funcs before 'return -ENOMEM' (Guchun).
 - keep the check of ' kiq->pmf' and 'kiq->pmf->kiq_unmap_queues' ahead
   of allocation of ring & ring_funcs (Guchun).

 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 32 ++++++++++++++++------
 1 file changed, 23 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
index 0040c63e2356..629ca1ad75a8 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c
@@ -836,33 +836,47 @@ int amdgpu_amdkfd_unmap_hiq(struct amdgpu_device *adev, u32 doorbell_off,
 {
 	struct amdgpu_kiq *kiq = &adev->gfx.kiq[inst];
 	struct amdgpu_ring *kiq_ring = &kiq->ring;
-	struct amdgpu_ring_funcs ring_funcs;
-	struct amdgpu_ring ring;
+	struct amdgpu_ring_funcs *ring_funcs;
+	struct amdgpu_ring *ring;
 	int r = 0;
 
 	if (!kiq->pmf || !kiq->pmf->kiq_unmap_queues)
 		return -EINVAL;
 
-	memset(&ring, 0x0, sizeof(struct amdgpu_ring));
-	memset(&ring_funcs, 0x0, sizeof(struct amdgpu_ring_funcs));
+	ring_funcs = kzalloc(sizeof(*ring_funcs), GFP_KERNEL);
+	if (!ring_funcs)
+		return -ENOMEM;
+
+	ring = kzalloc(sizeof(*ring), GFP_KERNEL);
+	if (!ring) {
+		r = -ENOMEM;
+		goto free_ring_funcs;
+	}
 
-	ring_funcs.type = AMDGPU_RING_TYPE_COMPUTE;
-	ring.doorbell_index = doorbell_off;
-	ring.funcs = &ring_funcs;
+	ring_funcs->type = AMDGPU_RING_TYPE_COMPUTE;
+	ring->doorbell_index = doorbell_off;
+	ring->funcs = ring_funcs;
 
 	spin_lock(&kiq->ring_lock);
 
 	if (amdgpu_ring_alloc(kiq_ring, kiq->pmf->unmap_queues_size)) {
 		spin_unlock(&kiq->ring_lock);
-		return -ENOMEM;
+		r = -ENOMEM;
+		goto free_ring;
 	}
 
-	kiq->pmf->kiq_unmap_queues(kiq_ring, &ring, RESET_QUEUES, 0, 0);
+	kiq->pmf->kiq_unmap_queues(kiq_ring, ring, RESET_QUEUES, 0, 0);
 
 	if (kiq_ring->sched.ready && !adev->job_hang)
 		r = amdgpu_ring_test_helper(kiq_ring);
 
 	spin_unlock(&kiq->ring_lock);
 
+free_ring:
+	kfree(ring);
+
+free_ring_funcs:
+	kfree(ring_funcs);
+
 	return r;
 }
-- 
2.25.1