From 7b975603677dae7196cd10decbfd2153584b13bd Mon Sep 17 00:00:00 2001
From: Philip Yang <Philip.Yang@amd.com>
Date: Wed, 1 Jun 2022 19:02:45 -0400
Subject: drm/amdgpu: Update PDEs flush TLB if PTB/PDB moved
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Git-commit: 4d1e5f12b7a0d2ade73003d2522a23b4559c7e02
Patch-mainline: v5.19-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

Flush TLBs when existing PDEs are updated because a PTB or PDB moved,
but avoids unnecessary TLB flushes when new PDBs or PTBs are added to
the page table, which commonly happens when memory is mapped for the
first time.

Suggested-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Philip Yang <Philip.Yang@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 2ceeaa4c793a..109d8dd71c11 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -679,6 +679,7 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
 {
 	struct amdgpu_vm_update_params params;
 	struct amdgpu_vm_bo_base *entry;
+	bool flush_tlb_needed = false;
 	int r, idx;
 
 	if (list_empty(&vm->relocated))
@@ -697,6 +698,9 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
 		goto error;
 
 	list_for_each_entry(entry, &vm->relocated, vm_status) {
+		/* vm_flush_needed after updating moved PDEs */
+		flush_tlb_needed |= entry->moved;
+
 		r = amdgpu_vm_pde_update(&params, entry);
 		if (r)
 			goto error;
@@ -706,8 +710,8 @@ int amdgpu_vm_update_pdes(struct amdgpu_device *adev,
 	if (r)
 		goto error;
 
-	/* vm_flush_needed after updating PDEs */
-	atomic64_inc(&vm->tlb_seq);
+	if (flush_tlb_needed)
+		atomic64_inc(&vm->tlb_seq);
 
 	while (!list_empty(&vm->relocated)) {
 		entry = list_first_entry(&vm->relocated,
-- 
2.38.1