[PATCH 2/2] drm/amdgpu: replace get_user_pages with HMM address mirror helpers v2

Yang, Philip Philip.Yang at amd.com
Thu Dec 6 21:01:56 UTC 2018


On 2018-12-03 8:52 p.m., Kuehling, Felix wrote:
> See comments inline. I didn't review the amdgpu_cs and amdgpu_gem parts
> as I don't know them very well.
>
> On 2018-12-03 3:19 p.m., Yang, Philip wrote:
>> 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.
>>
>> To avoid circular lock dependency, no nested locking between mmap_sem
>> and bo::reserve. The locking order is:
>> bo::reserve -> amdgpu_mn_lock(p->mn)
>>
>> 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().
>>
>> v2:
>> * Remove nested locking between mmap_sem and bo::reserve
>> * Change locking order to bo::reserve -> amdgpu_mn_lock()
>> * Use dynamic allocation to replace VLA in kernel stack
>>
>> Change-Id: Iffd5f855cc9ce402cdfca167f68f83fe39ac56f9
>> Signed-off-by: Philip Yang <Philip.Yang at amd.com>
>> ---
>>   .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c  | 101 ++++++++--
>>   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        | 188 +++++++++---------
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  14 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        |  34 +++-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_mn.h        |   7 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c       | 164 ++++++---------
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h       |   3 +-
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        |   1 -
>>   .../drm/amd/amdkfd/kfd_device_queue_manager.c |  67 ++++---
>>   11 files changed, 312 insertions(+), 272 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> index f3129b912714..5ce6ba24fc72 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
>> @@ -614,8 +614,7 @@ 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);
>> +	amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
>>   free_out:
>>   	kvfree(mem->user_pages);
>>   	mem->user_pages = NULL;
>> @@ -677,7 +676,6 @@ 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.shared = true;
>> -	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]);
>> @@ -741,7 +739,6 @@ 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.shared = true;
>> -	ctx->kfd_bo.user_pages = NULL;
>>   	list_add(&ctx->kfd_bo.tv.head, &ctx->list);
>>   
>>   	i = 0;
>> @@ -1332,9 +1329,6 @@ int amdgpu_amdkfd_gpuvm_free_memory_of_gpu(
>>   	/* 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);
>>   	}
>>   
>> @@ -1761,8 +1755,6 @@ static int update_invalid_user_pages(struct amdkfd_process_info *process_info,
>>   				       __func__);
>>   				return -ENOMEM;
>>   			}
>> -		} else if (mem->user_pages[0]) {
>> -			release_pages(mem->user_pages, bo->tbo.ttm->num_pages);
>>   		}
>>   
>>   		/* Get updated user pages */
>> @@ -1778,12 +1770,6 @@ 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;
>> @@ -1876,14 +1862,10 @@ 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.
>> +		 * our copy of the pointer array.
>>   		 */
>>   		kvfree(mem->user_pages);
>>   		mem->user_pages = NULL;
>> -		list_move_tail(&mem->validate_list.head,
>> -			       &process_info->userptr_valid_list);
>>   
>>   		/* Update mapping. If the BO was not validated
>>   		 * (because we couldn't get user pages), this will
>> @@ -1924,6 +1906,70 @@ static int validate_invalid_user_pages(struct amdkfd_process_info *process_info)
>>   	return ret;
>>   }
>>   
>> +/* user_pages_invalidated - if CPU page table is updated after getting user
>> + * pages
>> + *
>> + * HMM mirror callback lock amn is hold to prevent the concurrent CPU
>> + * page table update while resuming user queues.
>> + *
>> + * Returns: true if CPU page table is updated, false otherwise
>> + */
>> +static int user_pages_invalidated(struct mm_struct *mm,
>> +			struct amdkfd_process_info *process_info,
>> +			struct amdgpu_mn **amn)
>> +{
>> +	struct kgd_mem *mem, *tmp_mem;
>> +	struct amdgpu_bo *bo;
>> +	struct amdgpu_device *adev;
>> +	int invalid, r = 0;
>> +
>> +	list_for_each_entry_safe(mem, tmp_mem,
>> +				 &process_info->userptr_inval_list,
>> +				 validate_list.head) {
>> +
>> +		invalid = atomic_read(&mem->invalid);
>> +		if (!invalid)
>> +			/* BO hasn't been invalidated since the last
>> +			 * revalidation attempt. Keep its BO list.
>> +			 */
>> +			continue;
>> +
>> +		bo = mem->bo;
>> +
>> +		/* Get HMM mirror callback lock */
>> +		if (!*amn) {
>> +			adev = amdgpu_ttm_adev(bo->tbo.bdev);
>> +			*amn = amdgpu_mn_get(mm, adev, AMDGPU_MN_TYPE_HSA);
>> +			if (IS_ERR(*amn)) {
>> +				r = true;
>> +				*amn = NULL;
>> +				goto out;
>> +			}
>> +
>> +			amdgpu_mn_lock(*amn);
> There can be multiple GPUs involved here. So you'd need more than one
> amn lock. I think you're trying to use the amn lock to serialize page
> table updates. But that's probably not the right lock. What we should be
> using for this is the page directory reservation locks. We're already
> taking them for all affected GPUs in validate_invalid_user_pages. And
> that's where you should also be calling amdgpu_ttm_tt_get_user_pages_done.
>
Yes, this is incorrect for mGPU. Remove this function completely and add
calling amdgpu_tmm_tt_get_user_pages_done inside validate_invalid_user_pages
while holding the reservation locks.
>> +		}
>> +
>> +		r |= amdgpu_ttm_tt_get_user_pages_done(bo->tbo.ttm);
> This needs to be called while holding the "driver lock that serializes
> device page table updates". I think in our case that's the page
> directory reservation. You're not holding that here.
>
>
>> +
>> +		/* Put this BO back on the userptr_valid_list. If we need to
>> +		 * revalidate it, we need to start from scratch.
>> +		 */
>> +		list_move_tail(&mem->validate_list.head,
>> +			       &process_info->userptr_valid_list);
> Doing this unconditionally here looks wrong. Also, this was already done
> in validate_invalid_user_pages. So I'm wondering what's the point of
> this function. In most cases the process_info->userptr_inval_list will
> be empty here to begin with.
>
> I think you should probably call amdgpu_ttm_tt_get_user_pages_done in
> validate_invalid_user_pages while holding the PD reservation lock and
> where you call amdgpu_ttm_tt_set_user_pages.
>
>
>> +
>> +		/* Mark the BO as valid unless it was invalidated
>> +		 * again concurrently
>> +		 */
>> +		if (atomic_cmpxchg(&mem->invalid, invalid, 0) != invalid) {
>> +			r = true;
>> +			goto out;
>> +		}
>> +	}
>> +
>> +out:
>> +	return r;
>> +}
>> +
>>   /* Worker callback to restore evicted userptr BOs
>>    *
>>    * Tries to update and validate all userptr BOs. If successful and no
>> @@ -1939,6 +1985,7 @@ static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
>>   	struct task_struct *usertask;
>>   	struct mm_struct *mm;
>>   	int evicted_bos;
>> +	struct amdgpu_mn *amn = NULL;
>>   
>>   	evicted_bos = atomic_read(&process_info->evicted_bos);
>>   	if (!evicted_bos)
>> @@ -1977,13 +2024,27 @@ static void amdgpu_amdkfd_restore_userptr_worker(struct work_struct *work)
>>   	if (atomic_cmpxchg(&process_info->evicted_bos, evicted_bos, 0) !=
>>   	    evicted_bos)
>>   		goto unlock_out;
>> +
>> +	/* If CPU page table is updated again after getting user pages,
>> +	 * schedule to restart the restore process again.
>> +	 *
>> +	 * amn is also locked to prevent CPU page table update while resuming
>> +	 * user queues. amn is unlocked after user queues are resumed.
>> +	 */
>> +	if (user_pages_invalidated(mm, process_info, &amn))
>> +		goto unlock_mn_out;
>> +
>>   	evicted_bos = 0;
>> +
>>   	if (kgd2kfd->resume_mm(mm)) {
>>   		pr_err("%s: Failed to resume KFD\n", __func__);
>>   		/* No recovery from this failure. Probably the CP is
>>   		 * hanging. No point trying again.
>>   		 */
>>   	}
>> +
>> +unlock_mn_out:
>> +	amdgpu_mn_unlock(amn);
>>   unlock_out:
>>   	mutex_unlock(&process_info->lock);
>>   	mmput(mm);
> [snip]
>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
> b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
>> index 56595b3d90d2..6b6becdb725b 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);
>>   	}
>>   }
>>   
>> @@ -355,15 +353,16 @@ static struct hmm_mirror_ops amdgpu_hmm_mirror_ops[] = {
>>   /**
>>    * amdgpu_mn_get - create HMM mirror context
>>    *
>> + * @mm: the mm struct
>>    * @adev: amdgpu device pointer
>>    * @type: type of MMU notifier context
>>    *
>> - * Creates a HMM mirror context for current->mm.
>> + * Creates a HMM mirror context for mm.
>>    */
>> -struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>> +struct amdgpu_mn *amdgpu_mn_get(struct mm_struct *mm,
>> +				struct amdgpu_device *adev,
>>   				enum amdgpu_mn_type type)
>>   {
>> -	struct mm_struct *mm = current->mm;
>>   	struct amdgpu_mn *amn;
>>   	unsigned long key = AMDGPU_MN_KEY(mm, type);
>>   	int r;
>> @@ -433,7 +432,7 @@ int amdgpu_mn_register(struct amdgpu_bo *bo, unsigned long addr)
>>   	struct list_head bos;
>>   	struct interval_tree_node *it;
>>   
>> -	amn = amdgpu_mn_get(adev, type);
>> +	amn = amdgpu_mn_get(current->mm, adev, type);
>>   	if (IS_ERR(amn))
>>   		return PTR_ERR(amn);
>>   
>> @@ -515,3 +514,26 @@ 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 0e2752646e6f..59ea30e149bd 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,
>> @@ -37,10 +38,12 @@ enum amdgpu_mn_type {
>>   #if defined(CONFIG_HMM)
>>   void amdgpu_mn_lock(struct amdgpu_mn *mn);
>>   void amdgpu_mn_unlock(struct amdgpu_mn *mn);
>> -struct amdgpu_mn *amdgpu_mn_get(struct amdgpu_device *adev,
>> +struct amdgpu_mn *amdgpu_mn_get(struct mm_struct *mm,
>> +				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..4a1cb4d15dfb 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;
>> @@ -718,85 +714,91 @@ 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, 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->vma || range->vma->vm_file || range->vma->vm_end < end) {
> I think this breaks file-backed mappings and also adds a new limitation
> that the address range has to be a single VMA. This was previously only
> required it gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY.
Previously this vma is for sanity check only because get_user_pages do 
not need pass in vma.
now get_vma_fault expect a valid vma in range struct, change to keep 
previous check. Thanks.
>> +		r = -EPERM;
>> +		goto out;
>> +	}
>> +	range->pfns = kvmalloc_array(ttm->num_pages, sizeof(uint64_t),
>> +				GFP_KERNEL | __GFP_ZERO);
> Is GFP_ZERO really needed here? The loop below initializes all pfns
> explicitly.
GFP_ZERO is not needed.
>
>> +	if (range->pfns == NULL) {
>> +		r = -ENOMEM;
>> +		goto out;
>> +	}
>> +	range->start = gtt->userptr;
>> +	range->end = end;
>>   
>> -		vma = find_vma(mm, gtt->userptr);
>> -		if (!vma || vma->vm_file || vma->vm_end < end) {
>> -			up_read(&mm->mmap_sem);
>> -			return -EPERM;
>> -		}
>> +	for (i = 0; i < ttm->num_pages; i++) {
>> +		range->pfns[i] = range->flags[HMM_PFN_VALID];
>> +		range->pfns[i] |= amdgpu_ttm_tt_is_readonly(ttm) ?
>> +					0 : range->flags[HMM_PFN_WRITE];
>>   	}
>>   
>> -	/* 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;
>> +	/* This may triggles page table update */
> Do you mean "trigger"?
>
>
>> +	r = hmm_vma_fault(range, true);
>> +	if (r)
>> +		goto out_free_pfns;
>>   
>> -		guptask.task = current;
>> -		spin_lock(&gtt->guptasklock);
>> -		list_add(&guptask.list, &gtt->guptasks);
>> -		spin_unlock(&gtt->guptasklock);
>> +	for (i = 0; i < ttm->num_pages; i++)
>> +		pages[i] = hmm_pfn_to_page(range, range->pfns[i]);
>>   
>> -		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);
>> +	up_read(&mm->mmap_sem);
> You can probably up_read before the loop.
>
> Also, why do you defer freeing of range->pfns to
> amdgpu_ttm_tt_get_user_pages_done? The array isn't used for anything
> else later, so you could free it here.
>
> Or instead, don't free it and use it to replace the pages array. It
> seems wasteful to maintain two pages arrays and constantly allocate and
> deallocate one of them.
range->pfns will be used later by hmm_vma_range_done() in 
amdgpu_ttm_tt_get_user_pages_done
>
>> +	return 0;
>>   
>> -		spin_lock(&gtt->guptasklock);
>> -		list_del(&guptask.list);
>> -		spin_unlock(&gtt->guptasklock);
>> +out_free_pfns:
>> +	kvfree(range->pfns);
>> +	range->pfns = NULL;
> Setting range->pfns = NULL is not needed. This is a local variable
> that's about to go out of scope anyway.
range is a local pointer to gtt->range which will be freed in

amdgpu_ttm_tt_get_user_pages_done, assign to NULL to avoid double free.

>
>> +out:
>> +	up_read(&mm->mmap_sem);
>> +	return r;
>> +}
>>   
>> -		if (r < 0)
>> -			goto release_pages;
>> +/**
>> + * 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
>> + *
>> + * Returns: true if pages are invalidated since the last time they've been set
>> + */
>> +bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm)
>> +{
>> +	struct amdgpu_ttm_tt *gtt = (void *)ttm;
>> +	int r;
>>   
>> -		pinned += r;
>> +	if (gtt == NULL || !gtt->userptr)
>> +		return false;
>>   
>> -	} while (pinned < ttm->num_pages);
>> +	r = !hmm_vma_range_done(&gtt->range);
>>   
>> -	up_read(&mm->mmap_sem);
>> -	return 0;
>> +	if (gtt->range.pfns) {
>> +		kvfree(gtt->range.pfns);
>> +		gtt->range.pfns = NULL;
>> +	}
>>   
>> -release_pages:
>> -	release_pages(pages, pinned);
>> -	up_read(&mm->mmap_sem);
>>   	return r;
>>   }
>>   
>> @@ -809,16 +811,10 @@ 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)
> Does this function still make sense? It just copies a pages array. Could
> it instead use gtt->range->pfns directly? And why does this still have
> to be separate from amdgpu_ttm_tt_get_user_pages? I think originally it
> was separate because we needed to keep track of the original pages for
> unpinning them. But we're no longer pinning and unpinning pages.
>
Yes, remove mem->user_pages completely, use bo->tbo.ttm->pages instead.
>>   {
>> -	struct amdgpu_ttm_tt *gtt = (void *)ttm;
>>   	unsigned i;
>>   
>> -	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]);
>> -
>> +	for (i = 0; i < ttm->num_pages; ++i)
>>   		ttm->pages[i] = pages ? pages[i] : NULL;
> If this is still needed, it could just be a memcpy now.
>
>> -	}
>>   }
>>   
>>   /**
>> @@ -903,9 +899,6 @@ 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);
>>   }
>>   
>> @@ -1258,8 +1251,6 @@ 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 +1280,6 @@ 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 +1292,20 @@ 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..8988c87fff9d 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
>> @@ -102,6 +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);
>> +bool amdgpu_ttm_tt_get_user_pages_done(struct ttm_tt *ttm);
>>   void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct page **pages);
>>   void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm);
>>   int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
>> @@ -112,7 +113,7 @@ 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 2acb9838913e..4a67a88acea1 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
>> @@ -618,7 +618,6 @@ void amdgpu_vm_get_pd_bo(struct amdgpu_vm *vm,
>>   	entry->priority = 0;
>>   	entry->tv.bo = &vm->root.base.bo->tbo;
>>   	entry->tv.shared = true;
>> -	entry->user_pages = NULL;
>>   	list_add(&entry->tv.head, validated);
>>   }
>>   
>> diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> index 8372556b52eb..fe120cc0930c 100644
>> --- a/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
>> +++ b/drivers/gpu/drm/amd/amdkfd/kfd_device_queue_manager.c
> Please make everything below a separate commit.
Ok, submit separate patch for the changes below.
> Regards,
>    Felix
>
>
>> @@ -1158,6 +1158,33 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>>   
>>   	retval = 0;
>>   
>> +	/* Do init_mqd before dqm_lock(dqm) to avoid circular locking order:
>> +	 * lock(dqm) -> bo::reserve
>> +	 */
>> +	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
>> +			get_mqd_type_from_queue_type(q->properties.type));
>> +
>> +	if (!mqd_mgr) {
>> +		retval = -ENOMEM;
>> +		goto out;
>> +	}
>> +
>> +	/*
>> +	 * Eviction state logic: we only mark active queues as evicted
>> +	 * to avoid the overhead of restoring inactive queues later
>> +	 */
>> +	if (qpd->evicted)
>> +		q->properties.is_evicted = (q->properties.queue_size > 0 &&
>> +					    q->properties.queue_percent > 0 &&
>> +					    q->properties.queue_address != 0);
>> +	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
>> +	q->properties.tba_addr = qpd->tba_addr;
>> +	q->properties.tma_addr = qpd->tma_addr;
>> +	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
>> +				&q->gart_mqd_addr, &q->properties);
>> +	if (retval)
>> +		goto out;
>> +
>>   	dqm_lock(dqm);
>>   
>>   	if (dqm->total_queue_count >= max_num_of_queues_per_device) {
>> @@ -1181,30 +1208,6 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>>   	if (retval)
>>   		goto out_deallocate_sdma_queue;
>>   
>> -	mqd_mgr = dqm->ops.get_mqd_manager(dqm,
>> -			get_mqd_type_from_queue_type(q->properties.type));
>> -
>> -	if (!mqd_mgr) {
>> -		retval = -ENOMEM;
>> -		goto out_deallocate_doorbell;
>> -	}
>> -	/*
>> -	 * Eviction state logic: we only mark active queues as evicted
>> -	 * to avoid the overhead of restoring inactive queues later
>> -	 */
>> -	if (qpd->evicted)
>> -		q->properties.is_evicted = (q->properties.queue_size > 0 &&
>> -					    q->properties.queue_percent > 0 &&
>> -					    q->properties.queue_address != 0);
>> -
>> -	dqm->asic_ops.init_sdma_vm(dqm, q, qpd);
>> -
>> -	q->properties.tba_addr = qpd->tba_addr;
>> -	q->properties.tma_addr = qpd->tma_addr;
>> -	retval = mqd_mgr->init_mqd(mqd_mgr, &q->mqd, &q->mqd_mem_obj,
>> -				&q->gart_mqd_addr, &q->properties);
>> -	if (retval)
>> -		goto out_deallocate_doorbell;
>>   
>>   	list_add(&q->list, &qpd->queues_list);
>>   	qpd->queue_count++;
>> @@ -1228,14 +1231,12 @@ static int create_queue_cpsch(struct device_queue_manager *dqm, struct queue *q,
>>   	dqm_unlock(dqm);
>>   	return retval;
>>   
>> -out_deallocate_doorbell:
>> -	deallocate_doorbell(qpd, q);
>>   out_deallocate_sdma_queue:
>>   	if (q->properties.type == KFD_QUEUE_TYPE_SDMA)
>>   		deallocate_sdma_queue(dqm, q->sdma_id);
>>   out_unlock:
>>   	dqm_unlock(dqm);
>> -
>> +out:
>>   	return retval;
>>   }
>>   
>> @@ -1398,8 +1399,6 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
>>   			qpd->reset_wavefronts = true;
>>   	}
>>   
>> -	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
>> -
>>   	/*
>>   	 * Unconditionally decrement this counter, regardless of the queue's
>>   	 * type
>> @@ -1410,6 +1409,9 @@ static int destroy_queue_cpsch(struct device_queue_manager *dqm,
>>   
>>   	dqm_unlock(dqm);
>>   
>> +	/* Do uninit_mqd after dqm_unlock(dqm) to avoid circular locking */
>> +	mqd_mgr->uninit_mqd(mqd_mgr, q->mqd, q->mqd_mem_obj);
>> +
>>   	return retval;
>>   
>>   failed:
>> @@ -1631,7 +1633,11 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
>>   		qpd->reset_wavefronts = false;
>>   	}
>>   
>> -	/* lastly, free mqd resources */
>> +	dqm_unlock(dqm);
>> +
>> +	/* Lastly, free mqd resources.
>> +	 * Do uninit_mqd() after dqm_unlock to avoid circular locking.
>> +	 */
>>   	list_for_each_entry_safe(q, next, &qpd->queues_list, list) {
>>   		mqd_mgr = dqm->ops.get_mqd_manager(dqm,
>>   			get_mqd_type_from_queue_type(q->properties.type));
>> @@ -1645,7 +1651,6 @@ static int process_termination_cpsch(struct device_queue_manager *dqm,
>>   	}
>>   
>>   out:
>> -	dqm_unlock(dqm);
>>   	return retval;
>>   }
>>   



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