[PATCH 4/4] drm/amdkfd: create svm unregister range not overlap with userptr

[Philip Yang]

When creating new svm range to recover retry fault, avoid svm range
to overlap with ranges or userptr ranges managed by TTM, otherwise
svm migration will trigger TTM or userptr eviction, to evict user queues
unexpectedly.

Add helper amdgpu_ttm_tt_get_userptr because amdgpu_ttm_tt structure is
not accessed from outside of amdgpu_ttm.c.

Signed-off-by: Philip Yang <Philip.Yang at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 13 ++++++++++++
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h |  1 +
 drivers/gpu/drm/amd/amdkfd/kfd_svm.c    | 28 ++++++++++++++++++++++++-
 3 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index e2896ac2c9ce..93952e1bce5b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1251,6 +1251,19 @@ bool amdgpu_ttm_tt_is_userptr(struct ttm_tt *ttm)
 	return true;
 }
 
+/*
+ * amdgpu_ttm_tt_get_userptr - get userptr of the address range
+ */
+uint64_t amdgpu_ttm_tt_get_userptr(struct ttm_tt *ttm)
+{
+	struct amdgpu_ttm_tt *gtt = (void *)ttm;
+
+	if (gtt == NULL)
+		return 0;
+	return  gtt->userptr;
+}
+
+
 /*
  * amdgpu_ttm_tt_is_readonly - Is the ttm_tt object read only?
  */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index e69f3e8e06e5..1dd1a882280d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -186,6 +186,7 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
 bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
 				       int *last_invalidated);
 bool amdgpu_ttm_tt_is_userptr(struct ttm_tt *ttm);
+uint64_t amdgpu_ttm_tt_get_userptr(struct ttm_tt *ttm);
 bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm);
 uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_resource *mem);
 uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
index d49c08618714..a2eb21deb06f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_svm.c
@@ -45,6 +45,8 @@ static bool
 svm_range_cpu_invalidate_pagetables(struct mmu_interval_notifier *mni,
 				    const struct mmu_notifier_range *range,
 				    unsigned long cur_seq);
+static struct amdgpu_bo *
+svm_range_check_vm(struct kfd_process *p, uint64_t start, uint64_t last);
 
 static const struct mmu_interval_notifier_ops svm_range_mn_ops = {
 	.invalidate = svm_range_cpu_invalidate_pagetables,
@@ -2308,6 +2310,7 @@ svm_range_best_restore_location(struct svm_range *prange,
 
 	return -1;
 }
+
 static int
 svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
 				unsigned long *start, unsigned long *last)
@@ -2355,8 +2358,8 @@ svm_range_get_range_boundaries(struct kfd_process *p, int64_t addr,
 		  vma->vm_end >> PAGE_SHIFT, *last);
 
 	return 0;
-
 }
+
 static struct
 svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
 						struct kfd_process *p,
@@ -2366,10 +2369,33 @@ svm_range *svm_range_create_unregistered_range(struct amdgpu_device *adev,
 	struct svm_range *prange = NULL;
 	unsigned long start, last;
 	uint32_t gpuid, gpuidx;
+	struct amdgpu_bo *bo;
 
 	if (svm_range_get_range_boundaries(p, addr, &start, &last))
 		return NULL;
 
+	bo = svm_range_check_vm(p, start, last);
+	if (bo) {
+		struct ttm_tt *ttm = bo->tbo.ttm;
+		unsigned long bo_s, bo_l;
+
+		if (amdgpu_ttm_tt_is_userptr(ttm)) {
+			bo_s = amdgpu_ttm_tt_get_userptr(ttm) >> PAGE_SHIFT;
+			bo_l = bo_s + ttm->num_pages - 1;
+			pr_debug("overlap userptr [0x%lx 0x%lx]\n", bo_s, bo_l);
+		} else {
+			bo_s = bo->kfd_bo->va;
+			bo_l = bo_s + ttm->num_pages - 1;
+			pr_debug("overlap range [0x%lx 0x%lx]\n", bo_s, bo_l);
+		}
+		if (addr >= bo_s && addr <= bo_l)
+			return NULL;
+		if (addr < bo_s)
+			last = bo_s - 1;
+		if (addr > bo_l)
+			start = bo_l + 1;
+	}
+
 	prange = svm_range_new(&p->svms, start, last);
 	if (!prange) {
 		pr_debug("Failed to create prange in address [0x%llx]\n", addr);
-- 
2.17.1