[AMD Official Use Only - General]
On 2023-10-03 17:37, Felix Kuehling wrote:
On 2023-10-03 16:50, Philip Yang wrote:
If there is no VRAM domain, bo_node is NULL and this causes crash.
Refactor the change, and use the module parameter as higher privilege.
Need another patch to support override PTE flag on APU.
Fixes: 55d7e2001c7e ("drm/amdgpu: Add EXT_COHERENT memory allocation flags")
Signed-off-by: Philip Yang <philip.y...@amd.com><mailto:philip.y...@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_svm.c | 18 +++++++-----------
1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 0d88698ae33f..305b2c54edfa 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1248,26 +1248,22 @@ svm_range_get_pte_flags(struct kfd_node *node,
break;
case IP_VERSION(9, 4, 3):
mtype_local = amdgpu_mtype_local == 1 ? AMDGPU_VM_MTYPE_NC :
- (amdgpu_mtype_local == 2 ? AMDGPU_VM_MTYPE_CC :
AMDGPU_VM_MTYPE_RW);
+ (amdgpu_mtype_local == 2 || ext_coherent ?
+ AMDGPU_VM_MTYPE_CC : AMDGPU_VM_MTYPE_RW);
We had some offline discussion where I thought that MTYPE_NC should
become MTYPE_UC when ext_coherent is enabled to get the desired memory
semantics. With that idea in mind, this would become a bit more messy,
but here it goes, as clean as I can make it:
- mtype_local = amdgpu_mtype_local == 1 ? AMDGPU_VM_MTYPE_NC :
- (amdgpu_mtype_local == 2 ? AMDGPU_VM_MTYPE_CC :
AMDGPU_VM_MTYPE_RW);
+ mtype_local = amdgpu_mtype_local == 1 && !ext_coherent ?
AMDGPU_VM_MTYPE_NC :
+ (amdgpu_mtype_local == 1 && ext_coherent ?
AMDGPU_VM_MTYPE_UC :
+ (amdgpu_mtype_local == 2 || ext_coherent ?
AMDGPU_VM_MTYPE_CC :
+
AMDGPU_VM_MTYPE_RW));
That ternary looks fairly gnarly. I think it would be worth the extra ink to
write
mtype_local = amdgpu_mtype_local == 1 ? AMDGPU_VM_MTYPE_NC :
(amdgpu_mtype_local == 2 ? AMDGPU_VM_MTYPE_CC :
AMDGPU_VM_MTYPE_RW);
if (ext_coherent) {
if (amdgpu_mtype_local = 1)
mtype_local = AMDGPU_VM_MTYPE_UC;
else
mtype_local = AMDGPU_VM_MTYPE_CC;
}
But maybe that could be fixed up in a follow up patch. Either way, for
the purpose of fixing the crash, this patch is
Reviewed-by: Felix Kuehling
<felix.kuehl...@amd.com><mailto:felix.kuehl...@amd.com>
snoop = true;
if (uncached) {
mapping_flags |= AMDGPU_VM_MTYPE_UC;
- } else if (ext_coherent) {
- /* local HBM region close to partition */
- if (bo_node->adev == node->adev &&
- (!bo_node->xcp || !node->xcp || bo_node->xcp->mem_id
== node->xcp->mem_id))
- mapping_flags |= AMDGPU_VM_MTYPE_CC;
- else
- mapping_flags |= AMDGPU_VM_MTYPE_UC;
} else if (domain == SVM_RANGE_VRAM_DOMAIN) {
/* local HBM region close to partition */
if (bo_node->adev == node->adev &&
(!bo_node->xcp || !node->xcp || bo_node->xcp->mem_id
== node->xcp->mem_id))
mapping_flags |= mtype_local;
- /* local HBM region far from partition or remote XGMI GPU
*/
- else if (svm_nodes_in_same_hive(bo_node, node))
+ /* local HBM region far from partition or remote XGMI GPU
+ * with regular system scope coherence
+ */
+ else if (svm_nodes_in_same_hive(bo_node, node) &&
!ext_coherent)
mapping_flags |= AMDGPU_VM_MTYPE_NC;
- /* PCIe P2P */
+ /* PCIe P2P or extended system scope coherence */
else
mapping_flags |= AMDGPU_VM_MTYPE_UC;
Would probably clearer if these two branches were swapped so the first was
(!svm_nodes_in_same_hive(bo_node, node) || ext_coherent)
Not a required change, though.
/* system memory accessed by the APU */
This patch as written causes ext_coherent to no longer affect gfx9.4.3 APU
devices, which it should.
The following (or equivalent) needs to be added just below this hunk
if (num_possible_nodes() <= 1)
mapping_flags |= mtype_local;
else
- mapping_flags |= AMDGPU_VM_MTYPE_NC;
+ mapping_flags |= ext_coherent ? AMDGPU_VM_MTYPE_UC :
AMDGPU_VM_MTYPE_NC;
