4.2.8-ckt5 -stable review patch.  If anyone has any objections, please let me 
know.

---8<------------------------------------------------------------

From: =?UTF-8?q?Christian=20K=C3=B6nig?= <[email protected]>

commit cc1de6e800c253172334f8774c419dc64401cd2e upstream.

Otherwise we could try to evict overlapping userptr BOs in get_user_pages(),
leading to a possible circular locking dependency.

Signed-off-by: Christian König <[email protected]>
Acked-by: Alex Deucher <[email protected]>
Signed-off-by: Kamal Mostafa <[email protected]>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu.h     |  2 ++
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c  |  3 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 19 +++++++++++++++++++
 3 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 9af640e..b706455 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -2220,6 +2220,8 @@ bool amdgpu_ttm_bo_is_amdgpu_bo(struct ttm_buffer_object 
*bo);
 int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
                                     uint32_t flags);
 bool amdgpu_ttm_tt_has_userptr(struct ttm_tt *ttm);
+bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
+                                 unsigned long end);
 bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm);
 uint32_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt 
*ttm,
                                 struct ttm_mem_reg *mem);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index b1969f2..d4e2780 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -142,7 +142,8 @@ static void amdgpu_mn_invalidate_range_start(struct 
mmu_notifier *mn,
 
                list_for_each_entry(bo, &node->bos, mn_list) {
 
-                       if (!bo->tbo.ttm || bo->tbo.ttm->state != tt_bound)
+                       if (!amdgpu_ttm_tt_affect_userptr(bo->tbo.ttm, start,
+                                                         end))
                                continue;
 
                        r = amdgpu_bo_reserve(bo, true);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index beaa2fa..e3f73b7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -779,6 +779,25 @@ bool amdgpu_ttm_tt_has_userptr(struct ttm_tt *ttm)
        return !!gtt->userptr;
 }
 
+bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
+                                 unsigned long end)
+{
+       struct amdgpu_ttm_tt *gtt = (void *)ttm;
+       unsigned long size;
+
+       if (gtt == NULL)
+               return false;
+
+       if (gtt->ttm.ttm.state != tt_bound || !gtt->userptr)
+               return false;
+
+       size = (unsigned long)gtt->ttm.ttm.num_pages * PAGE_SIZE;
+       if (gtt->userptr > end || gtt->userptr + size <= start)
+               return false;
+
+       return true;
+}
+
 bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
 {
        struct amdgpu_ttm_tt *gtt = (void *)ttm;
-- 
2.7.0

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