[PATCH 2/2] drm/amdgpu: nuke amdgpu_vm_bo_split_mapping

Luben Tuikov luben.tuikov at amd.com
Wed Oct 14 20:48:57 UTC 2020


On 2020-10-13 13:08, Christian König wrote:
> Merge the functionality mostly into amdgpu_vm_bo_update_mapping.
> 
> This way we can even handle small contiguous system pages without
> to much extra CPU overhead.
> 
> Large contiguous allocations (1GB) still improve from 1.2 to 0.3 seconds.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 231 +++++++++++--------------
>  1 file changed, 103 insertions(+), 128 deletions(-)
> 
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> index 3cd949aad500..48342e54b2cb 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
> @@ -1429,21 +1429,18 @@ static void amdgpu_vm_fragment(struct amdgpu_vm_update_params *params,
>   * 0 for success, -EINVAL for failure.
>   */
>  static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
> +				 struct amdgpu_vm_pt_cursor *cursor,
>  				 uint64_t start, uint64_t end,
>  				 uint64_t dst, uint64_t flags)
>  {
>  	struct amdgpu_device *adev = params->adev;
> -	struct amdgpu_vm_pt_cursor cursor;
>  	uint64_t frag_start = start, frag_end;
>  	unsigned int frag;
>  	int r;
>  
>  	/* figure out the initial fragment */
>  	amdgpu_vm_fragment(params, frag_start, end, flags, &frag, &frag_end);
> -
> -	/* walk over the address space and update the PTs */
> -	amdgpu_vm_pt_start(adev, params->vm, start, &cursor);
> -	while (cursor.pfn < end) {
> +	while (cursor->pfn < end) {
>  		unsigned shift, parent_shift, mask;
>  		uint64_t incr, entry_end, pe_start;
>  		struct amdgpu_bo *pt;
> @@ -1453,22 +1450,22 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  			 * address range are actually allocated
>  			 */
>  			r = amdgpu_vm_alloc_pts(params->adev, params->vm,
> -						&cursor, params->immediate);
> +						cursor, params->immediate);
>  			if (r)
>  				return r;
>  		}
>  
> -		shift = amdgpu_vm_level_shift(adev, cursor.level);
> -		parent_shift = amdgpu_vm_level_shift(adev, cursor.level - 1);
> +		shift = amdgpu_vm_level_shift(adev, cursor->level);
> +		parent_shift = amdgpu_vm_level_shift(adev, cursor->level - 1);
>  		if (params->unlocked) {
>  			/* Unlocked updates are only allowed on the leaves */
> -			if (amdgpu_vm_pt_descendant(adev, &cursor))
> +			if (amdgpu_vm_pt_descendant(adev, cursor))
>  				continue;
>  		} else if (adev->asic_type < CHIP_VEGA10 &&
>  			   (flags & AMDGPU_PTE_VALID)) {
>  			/* No huge page support before GMC v9 */
> -			if (cursor.level != AMDGPU_VM_PTB) {
> -				if (!amdgpu_vm_pt_descendant(adev, &cursor))
> +			if (cursor->level != AMDGPU_VM_PTB) {
> +				if (!amdgpu_vm_pt_descendant(adev, cursor))
>  					return -ENOENT;
>  				continue;
>  			}
> @@ -1477,18 +1474,18 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  			 * smaller than the address shift. Go to the next
>  			 * child entry and try again.
>  			 */
> -			if (amdgpu_vm_pt_descendant(adev, &cursor))
> +			if (amdgpu_vm_pt_descendant(adev, cursor))
>  				continue;
>  		} else if (frag >= parent_shift) {
>  			/* If the fragment size is even larger than the parent
>  			 * shift we should go up one level and check it again.
>  			 */
> -			if (!amdgpu_vm_pt_ancestor(&cursor))
> +			if (!amdgpu_vm_pt_ancestor(cursor))
>  				return -EINVAL;
>  			continue;
>  		}
>  
> -		pt = cursor.entry->base.bo;
> +		pt = cursor->entry->base.bo;
>  		if (!pt) {
>  			/* We need all PDs and PTs for mapping something, */
>  			if (flags & AMDGPU_PTE_VALID)
> @@ -1497,10 +1494,10 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  			/* but unmapping something can happen at a higher
>  			 * level.
>  			 */
> -			if (!amdgpu_vm_pt_ancestor(&cursor))
> +			if (!amdgpu_vm_pt_ancestor(cursor))
>  				return -EINVAL;
>  
> -			pt = cursor.entry->base.bo;
> +			pt = cursor->entry->base.bo;
>  			shift = parent_shift;
>  			frag_end = max(frag_end, ALIGN(frag_start + 1,
>  				   1ULL << shift));
> @@ -1508,10 +1505,10 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  
>  		/* Looks good so far, calculate parameters for the update */
>  		incr = (uint64_t)AMDGPU_GPU_PAGE_SIZE << shift;
> -		mask = amdgpu_vm_entries_mask(adev, cursor.level);
> -		pe_start = ((cursor.pfn >> shift) & mask) * 8;
> +		mask = amdgpu_vm_entries_mask(adev, cursor->level);
> +		pe_start = ((cursor->pfn >> shift) & mask) * 8;
>  		entry_end = ((uint64_t)mask + 1) << shift;
> -		entry_end += cursor.pfn & ~(entry_end - 1);
> +		entry_end += cursor->pfn & ~(entry_end - 1);
>  		entry_end = min(entry_end, end);
>  
>  		do {
> @@ -1529,7 +1526,7 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  						    nptes, dst, incr, upd_flags,
>  						    vm->task_info.pid,
>  						    vm->immediate.fence_context);
> -			amdgpu_vm_update_flags(params, pt, cursor.level,
> +			amdgpu_vm_update_flags(params, pt, cursor->level,
>  					       pe_start, dst, nptes, incr,
>  					       upd_flags);
>  
> @@ -1546,21 +1543,21 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  			}
>  		} while (frag_start < entry_end);
>  
> -		if (amdgpu_vm_pt_descendant(adev, &cursor)) {
> +		if (amdgpu_vm_pt_descendant(adev, cursor)) {
>  			/* Free all child entries.
>  			 * Update the tables with the flags and addresses and free up subsequent
>  			 * tables in the case of huge pages or freed up areas.
>  			 * This is the maximum you can free, because all other page tables are not
>  			 * completely covered by the range and so potentially still in use.
>  			 */
> -			while (cursor.pfn < frag_start) {
> -				amdgpu_vm_free_pts(adev, params->vm, &cursor);
> -				amdgpu_vm_pt_next(adev, &cursor);
> +			while (cursor->pfn < frag_start) {
> +				amdgpu_vm_free_pts(adev, params->vm, cursor);
> +				amdgpu_vm_pt_next(adev, cursor);
>  			}
>  
>  		} else if (frag >= shift) {
>  			/* or just move on to the next on the same level. */
> -			amdgpu_vm_pt_next(adev, &cursor);
> +			amdgpu_vm_pt_next(adev, cursor);
>  		}
>  	}
>  
> @@ -1570,7 +1567,8 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>  /**
>   * amdgpu_vm_bo_update_mapping - update a mapping in the vm page table
>   *
> - * @adev: amdgpu_device pointer
> + * @adev: amdgpu_device pointer of the VM
> + * @bo_adev: amdgpu_device pointer of the mapped BO
>   * @vm: requested vm
>   * @immediate: immediate submission in a page fault
>   * @unlocked: unlocked invalidation during MM callback
> @@ -1578,7 +1576,8 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>   * @start: start of mapped range
>   * @last: last mapped entry
>   * @flags: flags for the entries
> - * @addr: addr to set the area to
> + * @offset: offset into nodes and pages_addr
> + * @nodes: array of drm_mm_nodes with the MC addresses
>   * @pages_addr: DMA addresses to use for mapping
>   * @fence: optional resulting fence
>   *
> @@ -1588,15 +1587,19 @@ static int amdgpu_vm_update_ptes(struct amdgpu_vm_update_params *params,
>   * 0 for success, -EINVAL for failure.
>   */
>  static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
> +				       struct amdgpu_device *bo_adev,
>  				       struct amdgpu_vm *vm, bool immediate,
>  				       bool unlocked, struct dma_resv *resv,
>  				       uint64_t start, uint64_t last,
> -				       uint64_t flags, uint64_t addr,
> +				       uint64_t flags, uint64_t offset,
> +				       struct drm_mm_node *nodes,
>  				       dma_addr_t *pages_addr,
>  				       struct dma_fence **fence)
>  {
>  	struct amdgpu_vm_update_params params;
> +	struct amdgpu_vm_pt_cursor cursor;
>  	enum amdgpu_sync_mode sync_mode;
> +	uint64_t pfn;
>  	int r;
>  
>  	memset(&params, 0, sizeof(params));
> @@ -1614,6 +1617,14 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
>  	else
>  		sync_mode = AMDGPU_SYNC_EXPLICIT;
>  
> +	pfn = offset >> PAGE_SHIFT;
> +	if (nodes) {
> +		while (pfn >= nodes->size) {
> +			pfn -= nodes->size;
> +			++nodes;
> +		}
> +	}
> +

I believe here you can just do:

	if (nodes)
		nodes += pfn / nodes->size;

So long as pfn and nodes->size are non-negative
integers and nodes->size is non-zero, which
conditions appear to be satisfied.

Regards,
Luben


>  	amdgpu_vm_eviction_lock(vm);
>  	if (vm->evicting) {
>  		r = -EBUSY;
> @@ -1632,105 +1643,47 @@ static int amdgpu_vm_bo_update_mapping(struct amdgpu_device *adev,
>  	if (r)
>  		goto error_unlock;
>  
> -	r = amdgpu_vm_update_ptes(&params, start, last + 1, addr, flags);
> -	if (r)
> -		goto error_unlock;
> -
> -	r = vm->update_funcs->commit(&params, fence);
> -
> -error_unlock:
> -	amdgpu_vm_eviction_unlock(vm);
> -	return r;
> -}
> -
> -/**
> - * amdgpu_vm_bo_split_mapping - split a mapping into smaller chunks
> - *
> - * @adev: amdgpu_device pointer
> - * @resv: fences we need to sync to
> - * @pages_addr: DMA addresses to use for mapping
> - * @vm: requested vm
> - * @mapping: mapped range and flags to use for the update
> - * @flags: HW flags for the mapping
> - * @bo_adev: amdgpu_device pointer that bo actually been allocated
> - * @nodes: array of drm_mm_nodes with the MC addresses
> - * @fence: optional resulting fence
> - *
> - * Split the mapping into smaller chunks so that each update fits
> - * into a SDMA IB.
> - *
> - * Returns:
> - * 0 for success, -EINVAL for failure.
> - */
> -static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
> -				      struct dma_resv *resv,
> -				      dma_addr_t *pages_addr,
> -				      struct amdgpu_vm *vm,
> -				      struct amdgpu_bo_va_mapping *mapping,
> -				      uint64_t flags,
> -				      struct amdgpu_device *bo_adev,
> -				      struct drm_mm_node *nodes,
> -				      struct dma_fence **fence)
> -{
> -	unsigned min_linear_pages = 1 << adev->vm_manager.fragment_size;
> -	uint64_t pfn, start = mapping->start;
> -	int r;
> -
> -	/* normally,bo_va->flags only contians READABLE and WIRTEABLE bit go here
> -	 * but in case of something, we filter the flags in first place
> -	 */
> -	if (!(mapping->flags & AMDGPU_PTE_READABLE))
> -		flags &= ~AMDGPU_PTE_READABLE;
> -	if (!(mapping->flags & AMDGPU_PTE_WRITEABLE))
> -		flags &= ~AMDGPU_PTE_WRITEABLE;
> -
> -	/* Apply ASIC specific mapping flags */
> -	amdgpu_gmc_get_vm_pte(adev, mapping, &flags);
> -
> -	trace_amdgpu_vm_bo_update(mapping);
> -
> -	pfn = mapping->offset >> PAGE_SHIFT;
> -	if (nodes) {
> -		while (pfn >= nodes->size) {
> -			pfn -= nodes->size;
> -			++nodes;
> -		}
> -	}
> -
> +	amdgpu_vm_pt_start(adev, vm, start, &cursor);
>  	do {
> -		dma_addr_t *dma_addr = NULL;
> -		uint64_t max_entries;
> -		uint64_t addr, last;
> +		uint64_t tmp, num_entries, addr;
>  
> -		max_entries = mapping->last - start + 1;
> +		num_entries = last - start + 1;
>  		if (nodes) {
>  			addr = nodes->start << PAGE_SHIFT;
> -			max_entries = min((nodes->size - pfn) *
> -				AMDGPU_GPU_PAGES_IN_CPU_PAGE, max_entries);
> +			num_entries = min((nodes->size - pfn) *
> +				AMDGPU_GPU_PAGES_IN_CPU_PAGE, num_entries);
>  		} else {
>  			addr = 0;
>  		}
>  
>  		if (pages_addr) {
> -			uint64_t count;
> +			bool contiguous = true;
>  
> -			for (count = 1;
> -			     count < max_entries / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
> -			     ++count) {
> -				uint64_t idx = pfn + count;
> +			if (num_entries < AMDGPU_GPU_PAGES_IN_CPU_PAGE) {
> +				uint64_t count;
>  
> -				if (pages_addr[idx] !=
> -				    (pages_addr[idx - 1] + PAGE_SIZE))
> -					break;
> +				contiguous = pages_addr[pfn + 1] ==
> +					pages_addr[pfn] + PAGE_SIZE;
> +
> +				tmp = num_entries /
> +					AMDGPU_GPU_PAGES_IN_CPU_PAGE;
> +				for (count = 2; count < tmp; ++count) {
> +					uint64_t idx = pfn + count;
> +
> +					if (contiguous != (pages_addr[idx] ==
> +					    pages_addr[idx - 1] + PAGE_SIZE))
> +						break;
> +				}
> +				num_entries = count *
> +					AMDGPU_GPU_PAGES_IN_CPU_PAGE;
>  			}
>  
> -			if (count < min_linear_pages) {
> +			if (!contiguous) {
>  				addr = pfn << PAGE_SHIFT;
> -				dma_addr = pages_addr;
> +				params.pages_addr = pages_addr;
>  			} else {
>  				addr = pages_addr[pfn];
> -				max_entries = count *
> -					AMDGPU_GPU_PAGES_IN_CPU_PAGE;
> +				params.pages_addr = NULL;
>  			}
>  
>  		} else if (flags & (AMDGPU_PTE_VALID | AMDGPU_PTE_PRT)) {
> @@ -1738,23 +1691,26 @@ static int amdgpu_vm_bo_split_mapping(struct amdgpu_device *adev,
>  			addr += pfn << PAGE_SHIFT;
>  		}
>  
> -		last = start + max_entries - 1;
> -		r = amdgpu_vm_bo_update_mapping(adev, vm, false, false, resv,
> -						start, last, flags, addr,
> -						dma_addr, fence);
> +		tmp = start + num_entries;
> +		r = amdgpu_vm_update_ptes(&params, &cursor, start, tmp, addr,
> +					  flags);
>  		if (r)
> -			return r;
> +			goto error_unlock;
>  
> -		pfn += (last - start + 1) / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
> +		pfn += num_entries / AMDGPU_GPU_PAGES_IN_CPU_PAGE;
>  		if (nodes && nodes->size == pfn) {
>  			pfn = 0;
>  			++nodes;
>  		}
> -		start = last + 1;
> +		start = tmp;
>  
> -	} while (unlikely(start != mapping->last + 1));
> +	} while (unlikely(start != last + 1));
>  
> -	return 0;
> +	r = vm->update_funcs->commit(&params, fence);
> +
> +error_unlock:
> +	amdgpu_vm_eviction_unlock(vm);
> +	return r;
>  }
>  
>  /**
> @@ -1835,9 +1791,26 @@ int amdgpu_vm_bo_update(struct amdgpu_device *adev, struct amdgpu_bo_va *bo_va,
>  	}
>  
>  	list_for_each_entry(mapping, &bo_va->invalids, list) {
> -		r = amdgpu_vm_bo_split_mapping(adev, resv, pages_addr, vm,
> -					       mapping, flags, bo_adev, nodes,
> -					       last_update);
> +		uint64_t update_flags = flags;
> +
> +		/* normally,bo_va->flags only contians READABLE and WIRTEABLE bit go here
> +		 * but in case of something, we filter the flags in first place
> +		 */
> +		if (!(mapping->flags & AMDGPU_PTE_READABLE))
> +			update_flags &= ~AMDGPU_PTE_READABLE;
> +		if (!(mapping->flags & AMDGPU_PTE_WRITEABLE))
> +			update_flags &= ~AMDGPU_PTE_WRITEABLE;
> +
> +		/* Apply ASIC specific mapping flags */
> +		amdgpu_gmc_get_vm_pte(adev, mapping, &update_flags);
> +
> +		trace_amdgpu_vm_bo_update(mapping);
> +
> +		r = amdgpu_vm_bo_update_mapping(adev, bo_adev, vm, false, false,
> +						resv, mapping->start,
> +						mapping->last, update_flags,
> +						mapping->offset, nodes,
> +						pages_addr, last_update);
>  		if (r)
>  			return r;
>  	}
> @@ -2045,9 +2018,10 @@ int amdgpu_vm_clear_freed(struct amdgpu_device *adev,
>  		    mapping->start < AMDGPU_GMC_HOLE_START)
>  			init_pte_value = AMDGPU_PTE_DEFAULT_ATC;
>  
> -		r = amdgpu_vm_bo_update_mapping(adev, vm, false, false, resv,
> -						mapping->start, mapping->last,
> -						init_pte_value, 0, NULL, &f);
> +		r = amdgpu_vm_bo_update_mapping(adev, adev, vm, false, false,
> +						resv, mapping->start,
> +						mapping->last, init_pte_value,
> +						0, NULL, NULL, &f);
>  		amdgpu_vm_free_mapping(adev, vm, mapping, f);
>  		if (r) {
>  			dma_fence_put(f);
> @@ -3375,8 +3349,9 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, unsigned int pasid,
>  		value = 0;
>  	}
>  
> -	r = amdgpu_vm_bo_update_mapping(adev, vm, true, false, NULL, addr,
> -					addr + 1, flags, value, NULL, NULL);
> +	r = amdgpu_vm_bo_update_mapping(adev, adev, vm, true, false, NULL, addr,
> +					addr + 1, flags, value, NULL, NULL,
> +					NULL);
>  	if (r)
>  		goto error_unlock;
>  
> 



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