From: Graham Sider <Graham.Sider@xxxxxxx>
By default, set use_mtype_cc_wa to 1 to set PTE coherence flag MTYPE_CC
instead of MTYPE_RW by default. This is required for the time being to
mitigate a bug causing XCCs to hit stale data due to TCC marking fully
dirty lines as exclusive.
Signed-off-by: Graham Sider <Graham.Sider@xxxxxxx>
Reviewed-by: Joseph Greathouse <Joseph.Greathouse@xxxxxxx>
Reviewed-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
---
drivers/gpu/drm/amd/amdgpu/amdgpu.h | 1 +
drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 7 +++++++
drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c | 10 +++++++---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 7 +++++--
4 files changed, 20 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 9904ce78b8fc..a3a0dbeb251f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -213,6 +213,7 @@ extern int amdgpu_noretry;
extern int amdgpu_force_asic_type;
extern int amdgpu_smartshift_bias;
extern int amdgpu_use_xgmi_p2p;
+extern bool amdgpu_use_mtype_cc_wa;
#ifdef CONFIG_HSA_AMD
extern int sched_policy;
extern bool debug_evictions;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
index e4d09bf0887d..2f38c49aa597 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
@@ -831,6 +831,13 @@ MODULE_PARM_DESC(no_queue_eviction_on_vm_fault, "No queue eviction on VM fault (
module_param_named(no_queue_eviction_on_vm_fault, amdgpu_no_queue_eviction_on_vm_fault, int, 0444);
#endif
+/**
+ * DOC: use_mtype_cc_wa (bool)
+ */
+bool amdgpu_use_mtype_cc_wa = true;
+MODULE_PARM_DESC(use_mtype_cc_wa, "Use MTYPE_CC workaround (0 = use MTYPE_RW where applicable, 1 = use MTYPE_CC where applicable (default))");
+module_param_named(use_mtype_cc_wa, amdgpu_use_mtype_cc_wa, bool, 0444);
+
/**
* DOC: pcie_p2p (bool)
* Enable PCIe P2P (requires large-BAR). Default value: true (on)
diff --git a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
index d28ffdb07ae6..59ce741dfa73 100644
--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -1192,6 +1192,7 @@ static void gmc_v9_0_get_coherence_flags(struct amdgpu_device *adev,
bool coherent = bo->flags & AMDGPU_GEM_CREATE_COHERENT;
bool uncached = bo->flags & AMDGPU_GEM_CREATE_UNCACHED;
unsigned int mtype;
+ unsigned int mtype_default;
bool snoop = false;
switch (adev->ip_versions[GC_HWIP][0]) {
@@ -1235,7 +1236,10 @@ static void gmc_v9_0_get_coherence_flags(struct amdgpu_device *adev,
/* FIXME: Needs more work for handling multiple memory
* partitions (> NPS1 mode) e.g. NPS4 for both APU and dGPU
* modes.
+ * FIXME: Temporarily using MTYPE_CC instead of MTYPE_RW where applicable.
+ * To force use of MTYPE_RW, set use_mtype_cc_wa=0
*/
+ mtype_default = amdgpu_use_mtype_cc_wa ? MTYPE_CC : MTYPE_RW;
snoop = true;
if (uncached) {
mtype = MTYPE_UC;
@@ -1250,14 +1254,14 @@ static void gmc_v9_0_get_coherence_flags(struct amdgpu_device *adev,
* socket should be treated as remote access so MTYPE_RW
* cannot be used always.
*/
- mtype = MTYPE_RW;
+ mtype = mtype_default;
} else if (adev->flags & AMD_IS_APU) {
/* APU on carve out mode */
- mtype = MTYPE_RW;
+ mtype = mtype_default;
} else {
/* dGPU */
if (is_vram && bo_adev == adev)
- mtype = MTYPE_RW;
+ mtype = mtype_default;
else if (is_vram)
mtype = MTYPE_NC;
else
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 83f8e4e50315..c55b9754c506 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1197,9 +1197,12 @@ svm_range_get_pte_flags(struct kfd_node *node,
if (uncached) {
mapping_flags |= AMDGPU_VM_MTYPE_UC;
} else if (domain == SVM_RANGE_VRAM_DOMAIN) {
- /* local HBM region close to partition */
+ /* local HBM region close to partition
+ * FIXME: Temporarily using MTYPE_CC instead of MTYPE_RW where applicable.
+ * To force use of MTYPE_RW, set use_mtype_cc_wa=0
+ */
if (bo_node == node)
- mapping_flags |= AMDGPU_VM_MTYPE_RW;
+ mapping_flags |= amdgpu_use_mtype_cc_wa ? AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW;
/* local HBM region far from partition or remote XGMI GPU */
else if (svm_nodes_in_same_hive(bo_node, node))
mapping_flags |= AMDGPU_VM_MTYPE_NC;
--
2.40.1
