From 31c5bc875cab058c074e70eccab5a1adba28a950 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20K=C3=B6nig?= <christian.koenig@amd.com>
Date: Fri, 7 Oct 2022 10:59:58 +0200
Subject: drm/amdgpu: use DRM_SCHED_FENCE_DONT_PIPELINE for VM updates
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Git-commit: 01f2cf53844b01e691516b465df1b6ab01b03230
Patch-mainline: v6.1-rc2
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225 jsc#PED-2849
Make sure that we always have a CPU round trip to let the submission
code correctly decide if a TLB flush is necessary or not.
Signed-off-by: Christian König <christian.koenig@amd.com>
Bug: https://gitlab.freedesktop.org/drm/amd/-/issues/2113#note_1579296
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Luben Tuikov <luben.tuikov@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221014081553.114899-2-christian.koenig@amd.com
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
index 2b0669c464f6..69e105fa41f6 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm_sdma.c
@@ -116,8 +116,15 @@ static int amdgpu_vm_sdma_commit(struct amdgpu_vm_update_params *p,
DMA_RESV_USAGE_BOOKKEEP);
}
- if (fence && !p->immediate)
+ if (fence && !p->immediate) {
+ /*
+ * Most hw generations now have a separate queue for page table
+ * updates, but when the queue is shared with userspace we need
+ * the extra CPU round trip to correctly flush the TLB.
+ */
+ set_bit(DRM_SCHED_FENCE_DONT_PIPELINE, &f->flags);
swap(*fence, f);
+ }
dma_fence_put(f);
return 0;
--
2.38.1