Commit 9a4087fa authored by Brett Creeley's avatar Brett Creeley Committed by Alex Williamson
Browse files

vfio: Commonize combine_ranges for use in other VFIO drivers 



Currently only Mellanox uses the combine_ranges function. The
new pds_vfio driver also needs this function. So, move it to
a common location for other vendor drivers to use.

Also, fix RCT ordering while moving/renaming the function.

Cc: Yishai Hadas <yishaih@nvidia.com>
Signed-off-by: default avatarBrett Creeley <brett.creeley@amd.com>
Signed-off-by: default avatarShannon Nelson <shannon.nelson@amd.com>
Reviewed-by: default avatarSimon Horman <horms@kernel.org>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Link: https://lore.kernel.org/r/20230807205755.29579-2-brett.creeley@amd.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 73e2f19d

drivers/vfio/pci/mlx5/cmd.c

+1 −47
Original line number Diff line number Diff line
@@ -732,52 +732,6 @@ void mlx5fv_cmd_clean_migf_resources(struct mlx5_vf_migration_file *migf) 
	mlx5vf_cmd_dealloc_pd(migf);

}



static void combine_ranges(struct rb_root_cached *root, u32 cur_nodes,

			   u32 req_nodes)

{

	struct interval_tree_node *prev, *curr, *comb_start, *comb_end;

	unsigned long min_gap;

	unsigned long curr_gap;



	/* Special shortcut when a single range is required */

	if (req_nodes == 1) {

		unsigned long last;



		curr = comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);

		while (curr) {

			last = curr->last;

			prev = curr;

			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);

			if (prev != comb_start)

				interval_tree_remove(prev, root);

		}

		comb_start->last = last;

		return;

	}



	/* Combine ranges which have the smallest gap */

	while (cur_nodes > req_nodes) {

		prev = NULL;

		min_gap = ULONG_MAX;

		curr = interval_tree_iter_first(root, 0, ULONG_MAX);

		while (curr) {

			if (prev) {

				curr_gap = curr->start - prev->last;

				if (curr_gap < min_gap) {

					min_gap = curr_gap;

					comb_start = prev;

					comb_end = curr;

				}

			}

			prev = curr;

			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);

		}

		comb_start->last = comb_end->last;

		interval_tree_remove(comb_end, root);

		cur_nodes--;

	}

}



static int mlx5vf_create_tracker(struct mlx5_core_dev *mdev,

				 struct mlx5vf_pci_core_device *mvdev,

				 struct rb_root_cached *ranges, u32 nnodes)
@@ -800,7 +754,7 @@ static int mlx5vf_create_tracker(struct mlx5_core_dev *mdev, 
	int i;



	if (num_ranges > max_num_range) {

		combine_ranges(ranges, nnodes, max_num_range);

		vfio_combine_iova_ranges(ranges, nnodes, max_num_range);

		num_ranges = max_num_range;

	}

drivers/vfio/vfio_main.c

+47 −0
Original line number Diff line number Diff line
@@ -935,6 +935,53 @@ static int vfio_ioctl_device_feature_migration(struct vfio_device *device, 
	return 0;

}



void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,

			      u32 req_nodes)

{

	struct interval_tree_node *prev, *curr, *comb_start, *comb_end;

	unsigned long min_gap, curr_gap;



	/* Special shortcut when a single range is required */

	if (req_nodes == 1) {

		unsigned long last;



		comb_start = interval_tree_iter_first(root, 0, ULONG_MAX);

		curr = comb_start;

		while (curr) {

			last = curr->last;

			prev = curr;

			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);

			if (prev != comb_start)

				interval_tree_remove(prev, root);

		}

		comb_start->last = last;

		return;

	}



	/* Combine ranges which have the smallest gap */

	while (cur_nodes > req_nodes) {

		prev = NULL;

		min_gap = ULONG_MAX;

		curr = interval_tree_iter_first(root, 0, ULONG_MAX);

		while (curr) {

			if (prev) {

				curr_gap = curr->start - prev->last;

				if (curr_gap < min_gap) {

					min_gap = curr_gap;

					comb_start = prev;

					comb_end = curr;

				}

			}

			prev = curr;

			curr = interval_tree_iter_next(curr, 0, ULONG_MAX);

		}

		comb_start->last = comb_end->last;

		interval_tree_remove(comb_end, root);

		cur_nodes--;

	}

}

EXPORT_SYMBOL_GPL(vfio_combine_iova_ranges);



/* Ranges should fit into a single kernel page */

#define LOG_MAX_RANGES \

	(PAGE_SIZE / sizeof(struct vfio_device_feature_dma_logging_range))

include/linux/vfio.h

+3 −0
Original line number Diff line number Diff line
@@ -283,6 +283,9 @@ int vfio_mig_get_next_state(struct vfio_device *device, 
			    enum vfio_device_mig_state new_fsm,

			    enum vfio_device_mig_state *next_fsm);



void vfio_combine_iova_ranges(struct rb_root_cached *root, u32 cur_nodes,

			      u32 req_nodes);



/*

 * External user API

 */