Use HMM helper function hmm_vma_fault() to get physical pages backing
userptr and start CPU page table update track of those pages. Then use
hmm_vma_range_done() to check if those pages are updated before
amdgpu_cs_submit for gfx or before user queues are resumed for kfd.

If userptr pages are updated, for gfx, amdgpu_cs_ioctl will restart
from scratch, for kfd, restore worker is rescheduled to retry.

HMM simplify the CPU page table concurrent update check, so remove
guptasklock, mmu_invalidations, last_set_pages fields from
amdgpu_ttm_tt struct.

HMM does not pin the page (increase page ref count), so remove related
operations like release_pages(), put_page(), mark_page_dirty().

Change-Id: I2e8c0c6f0d8c21e5596a32d7fc91762778bc9e67
Signed-off-by: Philip Yang <philip.y...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h    |   1 -
 .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  |  95 +++------
 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c   |   2 -
 drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h   |   3 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c        | 185 +++++++++---------
 drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  14 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        |  25 ++-
 drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   4 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       | 168 ++++++----------
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h       |   4 +-
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |   1 -
 11 files changed, 209 insertions(+), 293 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
index 70429f7aa9a8..717791d4fa45 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
@@ -62,7 +62,6 @@ struct kgd_mem {
 
        atomic_t invalid;
        struct amdkfd_process_info *process_info;
-       struct page **user_pages;
 
        struct amdgpu_sync sync;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
index be1ab43473c6..2897793600f7 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
@@ -582,28 +582,12 @@ static int init_user_pages(struct kgd_mem *mem, struct 
mm_struct *mm,
                goto out;
        }
 
-       /* If no restore worker is running concurrently, user_pages
-        * should not be allocated
-        */
-       WARN(mem->user_pages, "Leaking user_pages array");
-
-       mem->user_pages = kvmalloc_array(bo->tbo.ttm->num_pages,
-                                          sizeof(struct page *),
-                                          GFP_KERNEL | __GFP_ZERO);
-       if (!mem->user_pages) {
-               pr_err("%s: Failed to allocate pages array\n", __func__);
-               ret = -ENOMEM;
-               goto unregister_out;
-       }
-
-       ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, mem->user_pages);
+       ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, bo->tbo.ttm->pages);
        if (ret) {
                pr_err("%s: Failed to get user pages: %d\n", __func__, ret);
-               goto free_out;
+               goto unregister_out;
        }
 
-       amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm, mem->user_pages);
-
        ret = amdgpu_bo_reserve(bo, true);
        if (ret) {
                pr_err("%s: Failed to reserve BO\n", __func__);
@@ -616,11 +600,7 @@ static int init_user_pages(struct kgd_mem *mem, struct 
mm_struct *mm,
        amdgpu_bo_unreserve(bo);
 
 release_out:
-       if (ret)
-               release_pages(mem->user_pages, bo->tbo.ttm->num_pages);
-free_out:
-       kvfree(mem->user_pages);
-       mem->user_pages = NULL;
+       amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
 unregister_out:
        if (ret)
                amdgpu_mn_unregister(bo);
@@ -679,7 +659,6 @@ static int reserve_bo_and_vm(struct kgd_mem *mem,
        ctx->kfd_bo.priority = 0;
        ctx->kfd_bo.tv.bo = &bo->tbo;
        ctx->kfd_bo.tv.num_shared = 1;
-       ctx->kfd_bo.user_pages = NULL;
        list_add(&ctx->kfd_bo.tv.head, &ctx->list);
 
        amdgpu_vm_get_pd_bo(vm, &ctx->list, &ctx->vm_pd[0]);
@@ -743,7 +722,6 @@ static int reserve_bo_and_cond_vms(struct kgd_mem *mem,
        ctx->kfd_bo.priority = 0;
        ctx->kfd_bo.tv.bo = &bo->tbo;
        ctx->kfd_bo.tv.num_shared = 1;
-       ctx->kfd_bo.user_pages = NULL;
        list_add(&ctx->kfd_bo.tv.head, &ctx->list);
 
        i = 0;
@@ -1371,15 +1349,6 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
        list_del(&bo_list_entry->head);
        mutex_unlock(&process_info->lock);
 
-       /* Free user pages if necessary */
-       if (mem->user_pages) {
-               pr_debug("%s: Freeing user_pages array\n", __func__);
-               if (mem->user_pages[0])
-                       release_pages(mem->user_pages,
-                                       mem->bo->tbo.ttm->num_pages);
-               kvfree(mem->user_pages);
-       }
-
        ret = reserve_bo_and_cond_vms(mem, NULL, BO_VM_ALL, &ctx);
        if (unlikely(ret))
                return ret;
@@ -1855,25 +1824,11 @@ static int update_invalid_user_pages(struct 
amdkfd_process_info *process_info,
 
                bo = mem->bo;
 
-               if (!mem->user_pages) {
-                       mem->user_pages =
-                               kvmalloc_array(bo->tbo.ttm->num_pages,
-                                                sizeof(struct page *),
-                                                GFP_KERNEL | __GFP_ZERO);
-                       if (!mem->user_pages) {
-                               pr_err("%s: Failed to allocate pages array\n",
-                                      __func__);
-                               return -ENOMEM;
-                       }
-               } else if (mem->user_pages[0]) {
-                       release_pages(mem->user_pages, bo->tbo.ttm->num_pages);
-               }
-
                /* Get updated user pages */
                ret = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm,
-                                                  mem->user_pages);
+                                                  bo->tbo.ttm->pages);
                if (ret) {
-                       mem->user_pages[0] = NULL;
+                       bo->tbo.ttm->pages[0] = NULL;
                        pr_info("%s: Failed to get user pages: %d\n",
                                __func__, ret);
                        /* Pretend it succeeded. It will fail later
@@ -1882,12 +1837,6 @@ static int update_invalid_user_pages(struct 
amdkfd_process_info *process_info,
                         * stalled user mode queues.
                         */
                }
-
-               /* Mark the BO as valid unless it was invalidated
-                * again concurrently
-                */
-               if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid)
-                       return -EAGAIN;
        }
 
        return 0;
@@ -1917,7 +1866,8 @@ static int validate_invalid_user_pages(struct 
amdkfd_process_info *process_info)
                                     GFP_KERNEL);
        if (!pd_bo_list_entries) {
                pr_err("%s: Failed to allocate PD BO list entries\n", __func__);
-               return -ENOMEM;
+               ret = -ENOMEM;
+               goto out_no_mem;
        }
 
        INIT_LIST_HEAD(&resv_list);
@@ -1941,7 +1891,7 @@ static int validate_invalid_user_pages(struct 
amdkfd_process_info *process_info)
        ret = ttm_eu_reserve_buffers(&ticket, &resv_list, false, &duplicates);
        WARN(!list_empty(&duplicates), "Duplicates should be empty");
        if (ret)
-               goto out;
+               goto out_free;
 
        amdgpu_sync_create(&sync);
 
@@ -1967,10 +1917,8 @@ static int validate_invalid_user_pages(struct 
amdkfd_process_info *process_info)
 
                bo = mem->bo;
 
-               /* Copy pages array and validate the BO if we got user pages */
-               if (mem->user_pages[0]) {
-                       amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm,
-                                                    mem->user_pages);
+               /* Validate the BO if we got user pages */
+               if (bo->tbo.ttm->pages[0]) {
                        amdgpu_bo_placement_from_domain(bo, mem->domain);
                        ret = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
                        if (ret) {
@@ -1979,16 +1927,16 @@ static int validate_invalid_user_pages(struct 
amdkfd_process_info *process_info)
                        }
                }
 
-               /* Validate succeeded, now the BO owns the pages, free
-                * our copy of the pointer array. Put this BO back on
-                * the userptr_valid_list. If we need to revalidate
-                * it, we need to start from scratch.
-                */
-               kvfree(mem->user_pages);
-               mem->user_pages = NULL;
                list_move_tail(&mem->validate_list.head,
                               &process_info->userptr_valid_list);
 
+               /* Stop HMM track the userptr update. We dont check the return
+                * value for concurrent CPU page table update because we will
+                * reschedule the restore worker if process_info->evicted_bos
+                * is updated.
+                */
+               amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
+
                /* Update mapping. If the BO was not validated
                 * (because we couldn't get user pages), this will
                 * clear the page table entries, which will result in
@@ -2022,8 +1970,15 @@ static int validate_invalid_user_pages(struct 
amdkfd_process_info *process_info)
        ttm_eu_backoff_reservation(&ticket, &resv_list);
        amdgpu_sync_wait(&sync, false);
        amdgpu_sync_free(&sync);
-out:
+out_free:
        kfree(pd_bo_list_entries);
+out_no_mem:
+       list_for_each_entry_safe(mem, tmp_mem,
+                                &process_info->userptr_inval_list,
+                                validate_list.head) {
+               bo = mem->bo;
+               amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
+       }
 
        return ret;
 }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
index 5c79da8e1150..3842183970cc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.c
@@ -200,8 +200,6 @@ void amdgpu_bo_list_get_list(struct amdgpu_bo_list *list,
 
                if (!bo->parent)
                        list_add_tail(&e->tv.head, &bucket[priority]);
-
-               e->user_pages = NULL;
        }
 
        /* Connect the sorted buckets in the output list. */
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
index 7c5f5d1601e6..4beab2de09b3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bo_list.h
@@ -35,8 +35,7 @@ struct amdgpu_bo_list_entry {
        struct ttm_validate_buffer      tv;
        struct amdgpu_bo_va             *bo_va;
        uint32_t                        priority;
-       struct page                     **user_pages;
-       int                             user_invalidated;
+       bool                            user_invalidated;
 };
 
 struct amdgpu_bo_list {
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 1c49b8266d69..e30e39fb7224 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -52,7 +52,6 @@ static int amdgpu_cs_user_fence_chunk(struct amdgpu_cs_parser 
*p,
        p->uf_entry.tv.bo = &bo->tbo;
        /* One for TTM and one for the CS job */
        p->uf_entry.tv.num_shared = 2;
-       p->uf_entry.user_pages = NULL;
 
        drm_gem_object_put_unlocked(gobj);
 
@@ -532,24 +531,19 @@ static int amdgpu_cs_list_validate(struct 
amdgpu_cs_parser *p,
 
        list_for_each_entry(lobj, validated, tv.head) {
                struct amdgpu_bo *bo = ttm_to_amdgpu_bo(lobj->tv.bo);
-               bool binding_userptr = false;
                struct mm_struct *usermm;
 
                usermm = amdgpu_ttm_tt_get_usermm(bo->tbo.ttm);
                if (usermm && usermm != current->mm)
                        return -EPERM;
 
-               /* Check if we have user pages and nobody bound the BO already 
*/
-               if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm) &&
-                   lobj->user_pages) {
+               if (amdgpu_ttm_tt_is_userptr(bo->tbo.ttm) &&
+                   lobj->user_invalidated) {
                        amdgpu_bo_placement_from_domain(bo,
                                                        AMDGPU_GEM_DOMAIN_CPU);
                        r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
                        if (r)
                                return r;
-                       amdgpu_ttm_tt_set_user_pages(bo->tbo.ttm,
-                                                    lobj->user_pages);
-                       binding_userptr = true;
                }
 
                if (p->evictable == lobj)
@@ -558,11 +552,6 @@ static int amdgpu_cs_list_validate(struct amdgpu_cs_parser 
*p,
                r = amdgpu_cs_validate(p, bo);
                if (r)
                        return r;
-
-               if (binding_userptr) {
-                       kvfree(lobj->user_pages);
-                       lobj->user_pages = NULL;
-               }
        }
        return 0;
 }
@@ -577,7 +566,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
        struct amdgpu_bo *gds;
        struct amdgpu_bo *gws;
        struct amdgpu_bo *oa;
-       unsigned tries = 10;
+       struct list_head userpage_list;
        int r;
 
        INIT_LIST_HEAD(&p->validated);
@@ -586,7 +575,6 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
        if (cs->in.bo_list_handle) {
                if (p->bo_list)
                        return -EINVAL;
-
                r = amdgpu_bo_list_get(fpriv, cs->in.bo_list_handle,
                                       &p->bo_list);
                if (r)
@@ -613,79 +601,72 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser 
*p,
        if (p->uf_entry.tv.bo && !ttm_to_amdgpu_bo(p->uf_entry.tv.bo)->parent)
                list_add(&p->uf_entry.tv.head, &p->validated);
 
-       while (1) {
-               struct list_head need_pages;
+       r = ttm_eu_reserve_buffers(&p->ticket, &p->validated, true,
+                                  &duplicates);
+       if (unlikely(r != 0)) {
+               if (r != -ERESTARTSYS)
+                       DRM_ERROR("ttm_eu_reserve_buffers failed.\n");
+               goto out;
+       }
 
-               r = ttm_eu_reserve_buffers(&p->ticket, &p->validated, true,
-                                          &duplicates);
-               if (unlikely(r != 0)) {
-                       if (r != -ERESTARTSYS)
-                               DRM_ERROR("ttm_eu_reserve_buffers failed.\n");
-                       goto error_free_pages;
-               }
+       INIT_LIST_HEAD(&userpage_list);
+       amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
+               struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
 
-               INIT_LIST_HEAD(&need_pages);
-               amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
-                       struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
+               list_del(&e->tv.head);
+               list_add(&e->tv.head, &userpage_list);
+               amdgpu_bo_unreserve(bo);
+       }
 
-                       if (amdgpu_ttm_tt_userptr_invalidated(bo->tbo.ttm,
-                                &e->user_invalidated) && e->user_pages) {
+       /* Get userptr backing pages. If pages are updated after registered
+        * in amdgpu_gem_userptr_ioctl(), amdgpu_cs_list_validate() will do
+        * amdgpu_ttm_backend_bind() to flush and invalidate new pages
+        */
+       if (!list_empty(&userpage_list)) {
+               /* Unreserve everything again, to avoid circular locking case
+                * bo::reserve -> mmap->sem
+                */
+               ttm_eu_backoff_reservation(&p->ticket, &p->validated);
 
-                               /* We acquired a page array, but somebody
-                                * invalidated it. Free it and try again
-                                */
-                               release_pages(e->user_pages,
-                                             bo->tbo.ttm->num_pages);
-                               kvfree(e->user_pages);
-                               e->user_pages = NULL;
+               list_for_each_entry(e, &userpage_list, tv.head) {
+                       struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
+                       bool userpage_invalidated = false;
+                       struct page **pages;
+                       int i;
+
+                       pages = kvmalloc_array(bo->tbo.ttm->num_pages,
+                                               sizeof(*pages),
+                                               GFP_KERNEL | __GFP_ZERO);
+                       if (!pages) {
+                               DRM_ERROR("calloc failure\n");
+                               return -ENOMEM;
                        }
 
-                       if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm) &&
-                           !e->user_pages) {
-                               list_del(&e->tv.head);
-                               list_add(&e->tv.head, &need_pages);
-
-                               amdgpu_bo_unreserve(bo);
+                       r = amdgpu_ttm_tt_get_user_pages(bo->tbo.ttm, pages);
+                       if (r) {
+                               kvfree(pages);
+                               return r;
                        }
-               }
 
-               if (list_empty(&need_pages))
-                       break;
-
-               /* Unreserve everything again. */
-               ttm_eu_backoff_reservation(&p->ticket, &p->validated);
-
-               /* We tried too many times, just abort */
-               if (!--tries) {
-                       r = -EDEADLK;
-                       DRM_ERROR("deadlock in %s\n", __func__);
-                       goto error_free_pages;
+                       for (i = 0; i < bo->tbo.ttm->num_pages; i++) {
+                               if (bo->tbo.ttm->pages[i] != pages[i]) {
+                                       bo->tbo.ttm->pages[i] = pages[i];
+                                       userpage_invalidated = true;
+                               }
+                       }
+                       e->user_invalidated = userpage_invalidated;
+                       kvfree(pages);
                }
 
-               /* Fill the page arrays for all userptrs. */
-               list_for_each_entry(e, &need_pages, tv.head) {
-                       struct ttm_tt *ttm = e->tv.bo->ttm;
-
-                       e->user_pages = kvmalloc_array(ttm->num_pages,
-                                                        sizeof(struct page*),
-                                                        GFP_KERNEL | 
__GFP_ZERO);
-                       if (!e->user_pages) {
-                               r = -ENOMEM;
-                               DRM_ERROR("calloc failure in %s\n", __func__);
-                               goto error_free_pages;
-                       }
+               list_splice(&userpage_list, &p->validated);
 
-                       r = amdgpu_ttm_tt_get_user_pages(ttm, e->user_pages);
-                       if (r) {
-                               DRM_ERROR("amdgpu_ttm_tt_get_user_pages 
failed.\n");
-                               kvfree(e->user_pages);
-                               e->user_pages = NULL;
-                               goto error_free_pages;
-                       }
+               r = ttm_eu_reserve_buffers(&p->ticket, &p->validated, true,
+                                          &duplicates);
+               if (unlikely(r != 0)) {
+                       if (r != -ERESTARTSYS)
+                               DRM_ERROR("ttm_eu_reserve_buffers failed.\n");
+                       goto out;
                }
-
-               /* And try again. */
-               list_splice(&need_pages, &p->validated);
        }
 
        amdgpu_cs_get_threshold_for_moves(p->adev, &p->bytes_moved_threshold,
@@ -754,17 +735,7 @@ static int amdgpu_cs_parser_bos(struct amdgpu_cs_parser *p,
 error_validate:
        if (r)
                ttm_eu_backoff_reservation(&p->ticket, &p->validated);
-
-error_free_pages:
-
-       amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
-               if (!e->user_pages)
-                       continue;
-
-               release_pages(e->user_pages, e->tv.bo->ttm->num_pages);
-               kvfree(e->user_pages);
-       }
-
+out:
        return r;
 }
 
@@ -1213,8 +1184,7 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
        struct amdgpu_bo_list_entry *e;
        struct amdgpu_job *job;
        uint64_t seq;
-
-       int r;
+       int r = 0;
 
        job = p->job;
        p->job = NULL;
@@ -1223,15 +1193,21 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
        if (r)
                goto error_unlock;
 
-       /* No memory allocation is allowed while holding the mn lock */
+       /* No memory allocation is allowed while holding the mn lock.
+        * p->mn is hold until amdgpu_cs_submit is finished and fence is added
+        * to BOs.
+        */
        amdgpu_mn_lock(p->mn);
+
+       /* If userptr are updated after amdgpu_cs_parser_bos(), restart cs */
        amdgpu_bo_list_for_each_userptr_entry(e, p->bo_list) {
                struct amdgpu_bo *bo = ttm_to_amdgpu_bo(e->tv.bo);
 
-               if (amdgpu_ttm_tt_userptr_needs_pages(bo->tbo.ttm)) {
-                       r = -ERESTARTSYS;
-                       goto error_abort;
-               }
+               r |= !amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
+       }
+       if (r) {
+               r = -ERESTARTSYS;
+               goto error_abort;
        }
 
        job->owner = p->filp;
@@ -1278,14 +1254,20 @@ static int amdgpu_cs_submit(struct amdgpu_cs_parser *p,
 int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 {
        struct amdgpu_device *adev = dev->dev_private;
-       union drm_amdgpu_cs *cs = data;
-       struct amdgpu_cs_parser parser = {};
-       bool reserved_buffers = false;
+       union drm_amdgpu_cs *cs;
+       struct amdgpu_cs_parser parser;
+       bool reserved_buffers;
+       int tries = 10;
        int i, r;
 
        if (!adev->accel_working)
                return -EBUSY;
 
+restart:
+       memset(&parser, 0, sizeof(parser));
+       cs = data;
+       reserved_buffers = false;
+
        parser.adev = adev;
        parser.filp = filp;
 
@@ -1327,6 +1309,15 @@ int amdgpu_cs_ioctl(struct drm_device *dev, void *data, 
struct drm_file *filp)
 
 out:
        amdgpu_cs_parser_fini(&parser, r, reserved_buffers);
+
+       if (r == -ERESTARTSYS) {
+               if (!--tries) {
+                       DRM_ERROR("Possible deadlock? Retry too many times\n");
+                       return -EDEADLK;
+               }
+               goto restart;
+       }
+
        return r;
 }
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index f4f00217546e..92025993bfb1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -336,26 +336,24 @@ int amdgpu_gem_userptr_ioctl(struct drm_device *dev, void 
*data,
 
                r = amdgpu_bo_reserve(bo, true);
                if (r)
-                       goto free_pages;
+                       goto user_pages_done;
 
                amdgpu_bo_placement_from_domain(bo, AMDGPU_GEM_DOMAIN_GTT);
                r = ttm_bo_validate(&bo->tbo, &bo->placement, &ctx);
                amdgpu_bo_unreserve(bo);
                if (r)
-                       goto free_pages;
+                       goto user_pages_done;
        }
 
        r = drm_gem_handle_create(filp, gobj, &handle);
-       /* drop reference from allocate - handle holds it now */
-       drm_gem_object_put_unlocked(gobj);
        if (r)
-               return r;
+               goto user_pages_done;
 
        args->handle = handle;
-       return 0;
 
-free_pages:
-       release_pages(bo->tbo.ttm->pages, bo->tbo.ttm->num_pages);
+user_pages_done:
+       if (args->flags & AMDGPU_GEM_USERPTR_VALIDATE)
+               amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
 
 release_object:
        drm_gem_object_put_unlocked(gobj);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 5d518d2bb9be..9d40f3001f3c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -229,8 +229,6 @@ static void amdgpu_mn_invalidate_node(struct amdgpu_mn_node 
*node,
                        true, false, MAX_SCHEDULE_TIMEOUT);
                if (r <= 0)
                        DRM_ERROR("(%ld) failed to wait for user bo\n", r);
-
-               amdgpu_ttm_tt_mark_user_pages(bo->tbo.ttm);
        }
 }
 
@@ -513,3 +511,26 @@ void amdgpu_mn_unregister(struct amdgpu_bo *bo)
        mutex_unlock(&adev->mn_lock);
 }
 
+/* flags used by HMM internal, not related to CPU/GPU PTE flags */
+static const uint64_t hmm_range_flags[HMM_PFN_FLAG_MAX] = {
+               (1 << 0), /* HMM_PFN_VALID */
+               (1 << 1), /* HMM_PFN_WRITE */
+               0 /* HMM_PFN_DEVICE_PRIVATE */
+};
+
+static const uint64_t hmm_range_values[HMM_PFN_VALUE_MAX] = {
+               0xfffffffffffffffeUL, /* HMM_PFN_ERROR */
+               0, /* HMM_PFN_NONE */
+               0xfffffffffffffffcUL /* HMM_PFN_SPECIAL */
+};
+
+void amdgpu_hmm_init_range(struct hmm_range *range)
+{
+       if (range) {
+               range->flags = hmm_range_flags;
+               range->values = hmm_range_values;
+               range->pfn_shift = PAGE_SHIFT;
+               range->pfns = NULL;
+               INIT_LIST_HEAD(&range->list);
+       }
+}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
index 0a51fd00021c..4803e216e174 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h
@@ -25,9 +25,10 @@
 #define __AMDGPU_MN_H__
 
 /*
- * MMU Notifier
+ * HMM mirror
  */
 struct amdgpu_mn;
+struct hmm_range;
 
 enum amdgpu_mn_type {
        AMDGPU_MN_TYPE_GFX,
@@ -41,6 +42,7 @@ struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
                                enum amdgpu_mn_type type);
 int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr);
 void amdgpu_mn_unregister(struct amdgpu_bo *bo);
+void amdgpu_hmm_init_range(struct hmm_range *range);
 #else
 static inline void amdgpu_mn_lock(struct amdgpu_mn *mn) {}
 static inline void amdgpu_mn_unlock(struct amdgpu_mn *mn) {}
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index c91ec3101d00..70df6c68b4ed 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -43,6 +43,7 @@
 #include <linux/pagemap.h>
 #include <linux/debugfs.h>
 #include <linux/iommu.h>
+#include <linux/hmm.h>
 #include "amdgpu.h"
 #include "amdgpu_object.h"
 #include "amdgpu_trace.h"
@@ -705,11 +706,6 @@ static unsigned long amdgpu_ttm_io_mem_pfn(struct 
ttm_buffer_object *bo,
 /*
  * TTM backend functions.
  */
-struct amdgpu_ttm_gup_task_list {
-       struct list_head        list;
-       struct task_struct      *task;
-};
-
 struct amdgpu_ttm_tt {
        struct ttm_dma_tt       ttm;
        u64                     offset;
@@ -718,107 +714,97 @@ struct amdgpu_ttm_tt {
        uint32_t                userflags;
        spinlock_t              guptasklock;
        struct list_head        guptasks;
-       atomic_t                mmu_invalidations;
-       uint32_t                last_set_pages;
+       struct hmm_range        range;
 };
 
 /**
- * amdgpu_ttm_tt_get_user_pages - Pin pages of memory pointed to by a USERPTR
- * pointer to memory
+ * amdgpu_ttm_tt_get_user_pages - get device accessible pages that back user
+ * memory and start HMM tracking CPU page table update
  *
- * Called by amdgpu_gem_userptr_ioctl() and amdgpu_cs_parser_bos().
- * This provides a wrapper around the get_user_pages() call to provide
- * device accessible pages that back user memory.
+ * Calling function must call amdgpu_ttm_tt_userptr_range_done() once and only
+ * once afterwards to stop HMM tracking
  */
 int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages)
 {
        struct amdgpu_ttm_tt *gtt = (void *)ttm;
        struct mm_struct *mm = gtt->usertask->mm;
-       unsigned int flags = 0;
-       unsigned pinned = 0;
-       int r;
+       unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
+       struct hmm_range *range = &gtt->range;
+       int r = 0, i;
 
        if (!mm) /* Happens during process shutdown */
                return -ESRCH;
 
-       if (!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY))
-               flags |= FOLL_WRITE;
+       amdgpu_hmm_init_range(range);
 
        down_read(&mm->mmap_sem);
 
-       if (gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) {
-               /*
-                * check that we only use anonymous memory to prevent problems
-                * with writeback
-                */
-               unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
-               struct vm_area_struct *vma;
+       range->vma = find_vma(mm, gtt->userptr);
+       if (!range_in_vma(range->vma, gtt->userptr, end))
+               r = -EFAULT;
+       else if ((gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) &&
+               range->vma->vm_file)
+               r = -EPERM;
+       if (r)
+               goto out;
 
-               vma = find_vma(mm, gtt->userptr);
-               if (!vma || vma->vm_file || vma->vm_end < end) {
-                       up_read(&mm->mmap_sem);
-                       return -EPERM;
-               }
+       range->pfns = kvmalloc_array(ttm->num_pages, sizeof(uint64_t),
+                                    GFP_KERNEL);
+       if (range->pfns == NULL) {
+               r = -ENOMEM;
+               goto out;
        }
+       range->start = gtt->userptr;
+       range->end = end;
 
-       /* loop enough times using contiguous pages of memory */
-       do {
-               unsigned num_pages = ttm->num_pages - pinned;
-               uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
-               struct page **p = pages + pinned;
-               struct amdgpu_ttm_gup_task_list guptask;
-
-               guptask.task = current;
-               spin_lock(&gtt->guptasklock);
-               list_add(&guptask.list, &gtt->guptasks);
-               spin_unlock(&gtt->guptasklock);
-
-               if (mm == current->mm)
-                       r = get_user_pages(userptr, num_pages, flags, p, NULL);
-               else
-                       r = get_user_pages_remote(gtt->usertask,
-                                       mm, userptr, num_pages,
-                                       flags, p, NULL, NULL);
+       range->pfns[0] = range->flags[HMM_PFN_VALID];
+       range->pfns[0] |= amdgpu_ttm_tt_is_readonly(ttm) ?
+                               0 : range->flags[HMM_PFN_WRITE];
+       for (i = 1; i < ttm->num_pages; i++)
+               range->pfns[i] = range->pfns[0];
 
-               spin_lock(&gtt->guptasklock);
-               list_del(&guptask.list);
-               spin_unlock(&gtt->guptasklock);
-
-               if (r < 0)
-                       goto release_pages;
+       /* This may trigger page table update */
+       r = hmm_vma_fault(range, true);
+       if (r)
+               goto out_free_pfns;
 
-               pinned += r;
+       up_read(&mm->mmap_sem);
 
-       } while (pinned < ttm->num_pages);
+       for (i = 0; i < ttm->num_pages; i++)
+               pages[i] = hmm_pfn_to_page(range, range->pfns[i]);
 
-       up_read(&mm->mmap_sem);
        return 0;
 
-release_pages:
-       release_pages(pages, pinned);
+out_free_pfns:
+       kvfree(range->pfns);
+       range->pfns = NULL;
+out:
        up_read(&mm->mmap_sem);
        return r;
 }
 
 /**
- * amdgpu_ttm_tt_set_user_pages - Copy pages in, putting old pages as 
necessary.
+ * amdgpu_ttm_tt_userptr_range_done - stop HMM track the CPU page table change
+ * Check if the pages backing this ttm range have been invalidated
  *
- * Called by amdgpu_cs_list_validate(). This creates the page list
- * that backs user memory and will ultimately be mapped into the device
- * address space.
+ * Returns: true if pages are still valid
  */
-void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages)
+bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm)
 {
        struct amdgpu_ttm_tt *gtt = (void *)ttm;
-       unsigned i;
+       bool r = false;
 
-       gtt->last_set_pages = atomic_read(&gtt->mmu_invalidations);
-       for (i = 0; i < ttm->num_pages; ++i) {
-               if (ttm->pages[i])
-                       put_page(ttm->pages[i]);
+       if (!gtt || !gtt->userptr)
+               return false;
 
-               ttm->pages[i] = pages ? pages[i] : NULL;
+       WARN_ONCE(!gtt->range.pfns, "No user pages to check\n");
+       if (gtt->range.pfns) {
+               r = hmm_vma_range_done(&gtt->range);
+               kvfree(gtt->range.pfns);
+               gtt->range.pfns = NULL;
        }
+
+       return r;
 }
 
 /**
@@ -903,10 +889,9 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
        /* unmap the pages mapped to the device */
        dma_unmap_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
 
-       /* mark the pages as dirty */
-       amdgpu_ttm_tt_mark_user_pages(ttm);
-
        sg_free_table(ttm->sg);
+
+       WARN_ONCE(gtt->range.pfns, "Missing get_user_page_done\n");
 }
 
 int amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
@@ -1207,7 +1192,7 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
        bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);
 
        if (gtt && gtt->userptr) {
-               amdgpu_ttm_tt_set_user_pages(ttm, NULL);
+               memset(ttm->pages, 0, ttm->num_pages * sizeof(struct page *));
                kfree(ttm->sg);
                ttm->page_flags &= ~TTM_PAGE_FLAG_SG;
                return;
@@ -1258,8 +1243,6 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, 
uint64_t addr,
 
        spin_lock_init(&gtt->guptasklock);
        INIT_LIST_HEAD(&gtt->guptasks);
-       atomic_set(&gtt->mmu_invalidations, 0);
-       gtt->last_set_pages = 0;
 
        return 0;
 }
@@ -1289,7 +1272,6 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, 
unsigned long start,
                                  unsigned long end)
 {
        struct amdgpu_ttm_tt *gtt = (void *)ttm;
-       struct amdgpu_ttm_gup_task_list *entry;
        unsigned long size;
 
        if (gtt == NULL || !gtt->userptr)
@@ -1302,48 +1284,20 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, 
unsigned long start,
        if (gtt->userptr > end || gtt->userptr + size <= start)
                return false;
 
-       /* Search the lists of tasks that hold this mapping and see
-        * if current is one of them.  If it is return false.
-        */
-       spin_lock(&gtt->guptasklock);
-       list_for_each_entry(entry, &gtt->guptasks, list) {
-               if (entry->task == current) {
-                       spin_unlock(&gtt->guptasklock);
-                       return false;
-               }
-       }
-       spin_unlock(&gtt->guptasklock);
-
-       atomic_inc(&gtt->mmu_invalidations);
-
        return true;
 }
 
 /**
- * amdgpu_ttm_tt_userptr_invalidated - Has the ttm_tt object been invalidated?
+ * amdgpu_ttm_tt_is_userptr - Have the pages backing by userptr?
  */
-bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
-                                      int *last_invalidated)
-{
-       struct amdgpu_ttm_tt *gtt = (void *)ttm;
-       int prev_invalidated = *last_invalidated;
-
-       *last_invalidated = atomic_read(&gtt->mmu_invalidations);
-       return prev_invalidated != *last_invalidated;
-}
-
-/**
- * amdgpu_ttm_tt_userptr_needs_pages - Have the pages backing this ttm_tt 
object
- * been invalidated since the last time they've been set?
- */
-bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm)
+bool amdgpu_ttm_tt_is_userptr(struct ttm_tt *ttm)
 {
        struct amdgpu_ttm_tt *gtt = (void *)ttm;
 
        if (gtt == NULL || !gtt->userptr)
                return false;
 
-       return atomic_read(&gtt->mmu_invalidations) != gtt->last_set_pages;
+       return true;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index b5b2d101f7db..c5a1e78a09b1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -102,7 +102,7 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo);
 int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo);
 
 int amdgpu_ttm_tt_get_user_pages(struct ttm_tt *ttm, struct page **pages);
-void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages);
+bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm);
 void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm);
 int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
                                     uint32_t flags);
@@ -112,7 +112,7 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, 
unsigned long start,
                                  unsigned long end);
 bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
                                       int *last_invalidated);
-bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm);
+bool amdgpu_ttm_tt_is_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_mem_reg *mem);
 uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt 
*ttm,
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index e73d152659a2..1f8ab1a4fabc 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -619,7 +619,6 @@ void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
        entry->tv.bo = &vm->root.base.bo->tbo;
        /* One for the VM updates, one for TTM and one for the CS job */
        entry->tv.num_shared = 3;
-       entry->user_pages = NULL;
        list_add(&entry->tv.head, validated);
 }
 
-- 
2.17.1

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