Re: [PATCH] drm/amdkfd: only allow heavy-weight TLB flush on some ASICs for SVM too

[Felix Kuehling]

Am 2022-04-14 um 04:19 schrieb Lang Yu:
The idea is from commit a50fe7078035 ("drm/amdkfd: Only apply heavy-weight
TLB flush on Aldebaran") and commit f61c40c0757a ("drm/amdkfd: enable
heavy-weight TLB flush on Arcturus"). Otherwise, we will run into problems
on some ASICs when running SVM applications.

Signed-off-by: Lang Yu <lang...@amd.com>
---
  drivers/gpu/drm/amd/amdkfd/kfd_chardev.c | 8 --------
  drivers/gpu/drm/amd/amdkfd/kfd_priv.h    | 8 ++++++++
  drivers/gpu/drm/amd/amdkfd/kfd_svm.c     | 4 +++-
  3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 91f82a9ccdaf..459f59e3d0ed 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -1128,14 +1128,6 @@ static int kfd_ioctl_free_memory_of_gpu(struct file 
*filep,
        return ret;
  }
  
-static bool kfd_flush_tlb_after_unmap(struct kfd_dev *dev)
-{
-       return KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 2) ||
-               (KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 1) &&
-               dev->adev->sdma.instance[0].fw_version >= 18) ||
-               KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 0);
-}
-
  static int kfd_ioctl_map_memory_to_gpu(struct file *filep,
                                        struct kfd_process *p, void *data)
  {
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h 
b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index 8a43def1f638..aff6f598ff2c 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -1328,6 +1328,14 @@ void kfd_signal_poison_consumed_event(struct kfd_dev 
*dev, u32 pasid);
  
  void kfd_flush_tlb(struct kfd_process_device *pdd, enum TLB_FLUSH_TYPE type);
  
+static inline bool kfd_flush_tlb_after_unmap(struct kfd_dev *dev)
+{
+       return KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 2) ||
+              (KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 1) &&
+              dev->adev->sdma.instance[0].fw_version >= 18) ||
+              KFD_GC_VERSION(dev) == IP_VERSION(9, 4, 0);
+}
+
  bool kfd_is_locked(void);
  
  /* Compute profile */
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c 
b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index 459fa07a3bcc..5afe216cf099 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -1229,7 +1229,9 @@ svm_range_unmap_from_gpus(struct svm_range *prange, 
unsigned long start,
                        if (r)
                                break;
                }
-               kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);
+
+               if (kfd_flush_tlb_after_unmap(pdd->dev))
+                       kfd_flush_tlb(pdd, TLB_FLUSH_HEAVYWEIGHT);

Then you probably need to add another flush_tlb call in 
svm_range_map_to_gpus.

Regards,
  Felix


        }
  
  	return r;