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Commit c9990ab3 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Doug Ledford
Browse files

RDMA/umem: Move all the ODP related stuff out of ucontext and into per_mm 



This is the first step to make ODP use the owning_mm that is now part of
struct ib_umem.

Each ODP umem is linked to a single per_mm structure, which in turn, is
linked to a single mm, via the embedded mmu_notifier. This first patch
introduces the structure and reworks eveything to use it.

This also needs to introduce tgid into the ib_ucontext_per_mm, as
get_user_pages_remote() requires the originating task for statistics
tracking.

Signed-off-by: default avatarJason Gunthorpe <jgg@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: default avatarDoug Ledford <dledford@redhat.com>
parent 597ecc5a

drivers/infiniband/core/umem_odp.c

+68 −59
Original line number Diff line number Diff line
@@ -115,34 +115,35 @@ static void ib_umem_notifier_end_account(struct ib_umem_odp *umem_odp) 
}



/* Account for a new mmu notifier in an ib_ucontext. */

static void ib_ucontext_notifier_start_account(struct ib_ucontext *context)

static void

ib_ucontext_notifier_start_account(struct ib_ucontext_per_mm *per_mm)

{

	atomic_inc(&context->notifier_count);

	atomic_inc(&per_mm->notifier_count);

}



/* Account for a terminating mmu notifier in an ib_ucontext.

 *

 * Must be called with the ib_ucontext->umem_rwsem semaphore unlocked, since

 * the function takes the semaphore itself. */

static void ib_ucontext_notifier_end_account(struct ib_ucontext *context)

static void ib_ucontext_notifier_end_account(struct ib_ucontext_per_mm *per_mm)

{

	int zero_notifiers = atomic_dec_and_test(&context->notifier_count);

	int zero_notifiers = atomic_dec_and_test(&per_mm->notifier_count);



	if (zero_notifiers &&

	    !list_empty(&context->no_private_counters)) {

	    !list_empty(&per_mm->no_private_counters)) {

		/* No currently running mmu notifiers. Now is the chance to

		 * add private accounting to all previously added umems. */

		struct ib_umem_odp *odp_data, *next;



		/* Prevent concurrent mmu notifiers from working on the

		 * no_private_counters list. */

		down_write(&context->umem_rwsem);

		down_write(&per_mm->umem_rwsem);



		/* Read the notifier_count again, with the umem_rwsem

		 * semaphore taken for write. */

		if (!atomic_read(&context->notifier_count)) {

		if (!atomic_read(&per_mm->notifier_count)) {

			list_for_each_entry_safe(odp_data, next,

						 &context->no_private_counters,

						 &per_mm->no_private_counters,

						 no_private_counters) {

				mutex_lock(&odp_data->umem_mutex);

				odp_data->mn_counters_active = true;
@@ -152,7 +153,7 @@ static void ib_ucontext_notifier_end_account(struct ib_ucontext *context) 
			}

		}



		up_write(&context->umem_rwsem);

		up_write(&per_mm->umem_rwsem);

	}

}
@@ -179,19 +180,20 @@ static int ib_umem_notifier_release_trampoline(struct ib_umem_odp *umem_odp, 
static void ib_umem_notifier_release(struct mmu_notifier *mn,

				     struct mm_struct *mm)

{

	struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);

	struct ib_ucontext_per_mm *per_mm =

		container_of(mn, struct ib_ucontext_per_mm, mn);



	if (!context->invalidate_range)

	if (!per_mm->context->invalidate_range)

		return;



	ib_ucontext_notifier_start_account(context);

	down_read(&context->umem_rwsem);

	rbt_ib_umem_for_each_in_range(&context->umem_tree, 0,

	ib_ucontext_notifier_start_account(per_mm);

	down_read(&per_mm->umem_rwsem);

	rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, 0,

				      ULLONG_MAX,

				      ib_umem_notifier_release_trampoline,

				      true,

				      NULL);

	up_read(&context->umem_rwsem);

	up_read(&per_mm->umem_rwsem);

}



static int invalidate_page_trampoline(struct ib_umem_odp *item, u64 start,
@@ -217,23 +219,24 @@ static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn, 
						    unsigned long end,

						    bool blockable)

{

	struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);

	struct ib_ucontext_per_mm *per_mm =

		container_of(mn, struct ib_ucontext_per_mm, mn);

	int ret;



	if (!context->invalidate_range)

	if (!per_mm->context->invalidate_range)

		return 0;



	if (blockable)

		down_read(&context->umem_rwsem);

	else if (!down_read_trylock(&context->umem_rwsem))

		down_read(&per_mm->umem_rwsem);

	else if (!down_read_trylock(&per_mm->umem_rwsem))

		return -EAGAIN;



	ib_ucontext_notifier_start_account(context);

	ret = rbt_ib_umem_for_each_in_range(&context->umem_tree, start,

	ib_ucontext_notifier_start_account(per_mm);

	ret = rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, start,

				      end,

				      invalidate_range_start_trampoline,

				      blockable, NULL);

	up_read(&context->umem_rwsem);

	up_read(&per_mm->umem_rwsem);



	return ret;

}
@@ -250,9 +253,10 @@ static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, 
						  unsigned long start,

						  unsigned long end)

{

	struct ib_ucontext *context = container_of(mn, struct ib_ucontext, mn);

	struct ib_ucontext_per_mm *per_mm =

		container_of(mn, struct ib_ucontext_per_mm, mn);



	if (!context->invalidate_range)

	if (!per_mm->context->invalidate_range)

		return;



	/*
@@ -260,12 +264,12 @@ static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn, 
	 * in ib_umem_notifier_invalidate_range_start so we shouldn't really block

	 * here. But this is ugly and fragile.

	 */

	down_read(&context->umem_rwsem);

	rbt_ib_umem_for_each_in_range(&context->umem_tree, start,

	down_read(&per_mm->umem_rwsem);

	rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, start,

				      end,

				      invalidate_range_end_trampoline, true, NULL);

	up_read(&context->umem_rwsem);

	ib_ucontext_notifier_end_account(context);

	up_read(&per_mm->umem_rwsem);

	ib_ucontext_notifier_end_account(per_mm);

}



static const struct mmu_notifier_ops ib_umem_notifiers = {
@@ -277,6 +281,7 @@ static const struct mmu_notifier_ops ib_umem_notifiers = { 
struct ib_umem_odp *ib_alloc_odp_umem(struct ib_ucontext *context,

				      unsigned long addr, size_t size)

{

	struct ib_ucontext_per_mm *per_mm;

	struct ib_umem_odp *odp_data;

	struct ib_umem *umem;

	int pages = size >> PAGE_SHIFT;
@@ -292,6 +297,7 @@ struct ib_umem_odp *ib_alloc_odp_umem(struct ib_ucontext *context, 
	umem->page_shift = PAGE_SHIFT;

	umem->writable   = 1;

	umem->is_odp = 1;

	odp_data->per_mm = per_mm = &context->per_mm;



	mutex_init(&odp_data->umem_mutex);

	init_completion(&odp_data->notifier_completion);
@@ -310,15 +316,15 @@ struct ib_umem_odp *ib_alloc_odp_umem(struct ib_ucontext *context, 
		goto out_page_list;

	}



	down_write(&context->umem_rwsem);

	context->odp_mrs_count++;

	rbt_ib_umem_insert(&odp_data->interval_tree, &context->umem_tree);

	if (likely(!atomic_read(&context->notifier_count)))

	down_write(&per_mm->umem_rwsem);

	per_mm->odp_mrs_count++;

	rbt_ib_umem_insert(&odp_data->interval_tree, &per_mm->umem_tree);

	if (likely(!atomic_read(&per_mm->notifier_count)))

		odp_data->mn_counters_active = true;

	else

		list_add(&odp_data->no_private_counters,

			 &context->no_private_counters);

	up_write(&context->umem_rwsem);

			 &per_mm->no_private_counters);

	up_write(&per_mm->umem_rwsem);



	return odp_data;
@@ -334,6 +340,7 @@ int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 
{

	struct ib_ucontext *context = umem_odp->umem.context;

	struct ib_umem *umem = &umem_odp->umem;

	struct ib_ucontext_per_mm *per_mm;

	int ret_val;

	struct pid *our_pid;

	struct mm_struct *mm = get_task_mm(current);
@@ -396,28 +403,30 @@ int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 
	 * notification before the "current" task (and MM) is

	 * destroyed. We use the umem_rwsem semaphore to synchronize.

	 */

	down_write(&context->umem_rwsem);

	context->odp_mrs_count++;

	umem_odp->per_mm = per_mm = &context->per_mm;



	down_write(&per_mm->umem_rwsem);

	per_mm->odp_mrs_count++;

	if (likely(ib_umem_start(umem) != ib_umem_end(umem)))

		rbt_ib_umem_insert(&umem_odp->interval_tree,

				   &context->umem_tree);

	if (likely(!atomic_read(&context->notifier_count)) ||

	    context->odp_mrs_count == 1)

				   &per_mm->umem_tree);

	if (likely(!atomic_read(&per_mm->notifier_count)) ||

	    per_mm->odp_mrs_count == 1)

		umem_odp->mn_counters_active = true;

	else

		list_add(&umem_odp->no_private_counters,

			 &context->no_private_counters);

	downgrade_write(&context->umem_rwsem);

			 &per_mm->no_private_counters);

	downgrade_write(&per_mm->umem_rwsem);



	if (context->odp_mrs_count == 1) {

	if (per_mm->odp_mrs_count == 1) {

		/*

		 * Note that at this point, no MMU notifier is running

		 * for this context!

		 * for this per_mm!

		 */

		atomic_set(&context->notifier_count, 0);

		INIT_HLIST_NODE(&context->mn.hlist);

		context->mn.ops = &ib_umem_notifiers;

		ret_val = mmu_notifier_register(&context->mn, mm);

		atomic_set(&per_mm->notifier_count, 0);

		INIT_HLIST_NODE(&per_mm->mn.hlist);

		per_mm->mn.ops = &ib_umem_notifiers;

		ret_val = mmu_notifier_register(&per_mm->mn, mm);

		if (ret_val) {

			pr_err("Failed to register mmu_notifier %d\n", ret_val);

			ret_val = -EBUSY;
@@ -425,7 +434,7 @@ int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 
		}

	}



	up_read(&context->umem_rwsem);

	up_read(&per_mm->umem_rwsem);



	/*

	 * Note that doing an mmput can cause a notifier for the relevant mm.
@@ -437,7 +446,7 @@ int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 
	return 0;



out_mutex:

	up_read(&context->umem_rwsem);

	up_read(&per_mm->umem_rwsem);

	vfree(umem_odp->dma_list);

out_page_list:

	vfree(umem_odp->page_list);
@@ -449,7 +458,7 @@ int ib_umem_odp_get(struct ib_umem_odp *umem_odp, int access) 
void ib_umem_odp_release(struct ib_umem_odp *umem_odp)

{

	struct ib_umem *umem = &umem_odp->umem;

	struct ib_ucontext *context = umem->context;

	struct ib_ucontext_per_mm *per_mm = umem_odp->per_mm;



	/*

	 * Ensure that no more pages are mapped in the umem.
@@ -460,11 +469,11 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp) 
	ib_umem_odp_unmap_dma_pages(umem_odp, ib_umem_start(umem),

				    ib_umem_end(umem));



	down_write(&context->umem_rwsem);

	down_write(&per_mm->umem_rwsem);

	if (likely(ib_umem_start(umem) != ib_umem_end(umem)))

		rbt_ib_umem_remove(&umem_odp->interval_tree,

				   &context->umem_tree);

	context->odp_mrs_count--;

				   &per_mm->umem_tree);

	per_mm->odp_mrs_count--;

	if (!umem_odp->mn_counters_active) {

		list_del(&umem_odp->no_private_counters);

		complete_all(&umem_odp->notifier_completion);
@@ -477,13 +486,13 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp) 
	 * that since we are doing it atomically, no other user could register

	 * and unregister while we do the check.

	 */

	downgrade_write(&context->umem_rwsem);

	if (!context->odp_mrs_count) {

	downgrade_write(&per_mm->umem_rwsem);

	if (!per_mm->odp_mrs_count) {

		struct task_struct *owning_process = NULL;

		struct mm_struct *owning_mm        = NULL;



		owning_process = get_pid_task(context->tgid,

					      PIDTYPE_PID);

		owning_process =

			get_pid_task(umem_odp->umem.context->tgid, PIDTYPE_PID);

		if (owning_process == NULL)

			/*

			 * The process is already dead, notifier were removed
@@ -498,7 +507,7 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp) 
			 * removed already.

			 */

			goto out_put_task;

		mmu_notifier_unregister(&context->mn, owning_mm);

		mmu_notifier_unregister(&per_mm->mn, owning_mm);



		mmput(owning_mm);
@@ -506,7 +515,7 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp) 
		put_task_struct(owning_process);

	}

out:

	up_read(&context->umem_rwsem);

	up_read(&per_mm->umem_rwsem);



	vfree(umem_odp->dma_list);

	vfree(umem_odp->page_list);

drivers/infiniband/core/uverbs_cmd.c

+5 −4
Original line number Diff line number Diff line
@@ -124,10 +124,11 @@ ssize_t ib_uverbs_get_context(struct ib_uverbs_file *file, 
	ucontext->cleanup_retryable = false;



#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING

	ucontext->umem_tree = RB_ROOT_CACHED;

	init_rwsem(&ucontext->umem_rwsem);

	ucontext->odp_mrs_count = 0;

	INIT_LIST_HEAD(&ucontext->no_private_counters);

	ucontext->per_mm.umem_tree = RB_ROOT_CACHED;

	init_rwsem(&ucontext->per_mm.umem_rwsem);

	ucontext->per_mm.odp_mrs_count = 0;

	INIT_LIST_HEAD(&ucontext->per_mm.no_private_counters);

	ucontext->per_mm.context = ucontext;



	if (!(ib_dev->attrs.device_cap_flags & IB_DEVICE_ON_DEMAND_PAGING))

		ucontext->invalidate_range = NULL;

drivers/infiniband/hw/mlx5/odp.c

+25 −18
Original line number Diff line number Diff line
@@ -61,13 +61,21 @@ static int check_parent(struct ib_umem_odp *odp, 
	return mr && mr->parent == parent && !odp->dying;

}



struct ib_ucontext_per_mm *mr_to_per_mm(struct mlx5_ib_mr *mr)

{

	if (WARN_ON(!mr || !mr->umem || !mr->umem->is_odp))

		return NULL;



	return to_ib_umem_odp(mr->umem)->per_mm;

}



static struct ib_umem_odp *odp_next(struct ib_umem_odp *odp)

{

	struct mlx5_ib_mr *mr = odp->private, *parent = mr->parent;

	struct ib_ucontext *ctx = odp->umem.context;

	struct ib_ucontext_per_mm *per_mm = odp->per_mm;

	struct rb_node *rb;



	down_read(&ctx->umem_rwsem);

	down_read(&per_mm->umem_rwsem);

	while (1) {

		rb = rb_next(&odp->interval_tree.rb);

		if (!rb)
@@ -79,19 +87,19 @@ static struct ib_umem_odp *odp_next(struct ib_umem_odp *odp) 
not_found:

	odp = NULL;

end:

	up_read(&ctx->umem_rwsem);

	up_read(&per_mm->umem_rwsem);

	return odp;

}



static struct ib_umem_odp *odp_lookup(struct ib_ucontext *ctx,

				      u64 start, u64 length,

static struct ib_umem_odp *odp_lookup(u64 start, u64 length,

				      struct mlx5_ib_mr *parent)

{

	struct ib_ucontext_per_mm *per_mm = mr_to_per_mm(parent);

	struct ib_umem_odp *odp;

	struct rb_node *rb;



	down_read(&ctx->umem_rwsem);

	odp = rbt_ib_umem_lookup(&ctx->umem_tree, start, length);

	down_read(&per_mm->umem_rwsem);

	odp = rbt_ib_umem_lookup(&per_mm->umem_tree, start, length);

	if (!odp)

		goto end;
@@ -108,7 +116,7 @@ static struct ib_umem_odp *odp_lookup(struct ib_ucontext *ctx, 
not_found:

	odp = NULL;

end:

	up_read(&ctx->umem_rwsem);

	up_read(&per_mm->umem_rwsem);

	return odp;

}
@@ -116,7 +124,6 @@ void mlx5_odp_populate_klm(struct mlx5_klm *pklm, size_t offset, 
			   size_t nentries, struct mlx5_ib_mr *mr, int flags)

{

	struct ib_pd *pd = mr->ibmr.pd;

	struct ib_ucontext *ctx = pd->uobject->context;

	struct mlx5_ib_dev *dev = to_mdev(pd->device);

	struct ib_umem_odp *odp;

	unsigned long va;
@@ -131,7 +138,7 @@ void mlx5_odp_populate_klm(struct mlx5_klm *pklm, size_t offset, 
		return;

	}



	odp = odp_lookup(ctx, offset * MLX5_IMR_MTT_SIZE,

	odp = odp_lookup(offset * MLX5_IMR_MTT_SIZE,

			 nentries * MLX5_IMR_MTT_SIZE, mr);



	for (i = 0; i < nentries; i++, pklm++) {
@@ -368,7 +375,6 @@ static struct mlx5_ib_mr *implicit_mr_alloc(struct ib_pd *pd, 
static struct ib_umem_odp *implicit_mr_get_data(struct mlx5_ib_mr *mr,

						u64 io_virt, size_t bcnt)

{

	struct ib_ucontext *ctx = mr->ibmr.pd->uobject->context;

	struct mlx5_ib_dev *dev = to_mdev(mr->ibmr.pd->device);

	struct ib_umem_odp *odp, *result = NULL;

	struct ib_umem_odp *odp_mr = to_ib_umem_odp(mr->umem);
@@ -377,7 +383,7 @@ static struct ib_umem_odp *implicit_mr_get_data(struct mlx5_ib_mr *mr, 
	struct mlx5_ib_mr *mtt;



	mutex_lock(&odp_mr->umem_mutex);

	odp = odp_lookup(ctx, addr, 1, mr);

	odp = odp_lookup(addr, 1, mr);



	mlx5_ib_dbg(dev, "io_virt:%llx bcnt:%zx addr:%llx odp:%p\n",

		    io_virt, bcnt, addr, odp);
@@ -387,7 +393,8 @@ static struct ib_umem_odp *implicit_mr_get_data(struct mlx5_ib_mr *mr, 
		if (nentries)

			nentries++;

	} else {

		odp = ib_alloc_odp_umem(ctx, addr, MLX5_IMR_MTT_SIZE);

		odp = ib_alloc_odp_umem(odp_mr->umem.context, addr,

					MLX5_IMR_MTT_SIZE);

		if (IS_ERR(odp)) {

			mutex_unlock(&odp_mr->umem_mutex);

			return ERR_CAST(odp);
@@ -486,12 +493,12 @@ static int mr_leaf_free(struct ib_umem_odp *umem_odp, u64 start, u64 end, 


void mlx5_ib_free_implicit_mr(struct mlx5_ib_mr *imr)

{

	struct ib_ucontext *ctx = imr->ibmr.pd->uobject->context;

	struct ib_ucontext_per_mm *per_mm = mr_to_per_mm(imr);



	down_read(&ctx->umem_rwsem);

	rbt_ib_umem_for_each_in_range(&ctx->umem_tree, 0, ULLONG_MAX,

	down_read(&per_mm->umem_rwsem);

	rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, 0, ULLONG_MAX,

				      mr_leaf_free, true, imr);

	up_read(&ctx->umem_rwsem);

	up_read(&per_mm->umem_rwsem);



	wait_event(imr->q_leaf_free, !atomic_read(&imr->num_leaf_free));

}

include/rdma/ib_umem_odp.h

+2 −0
Original line number Diff line number Diff line
@@ -44,6 +44,8 @@ struct umem_odp_node { 


struct ib_umem_odp {

	struct ib_umem umem;

	struct ib_ucontext_per_mm *per_mm;



	/*

	 * An array of the pages included in the on-demand paging umem.

	 * Indices of pages that are currently not mapped into the device will

include/rdma/ib_verbs.h

+20 −12
Original line number Diff line number Diff line
@@ -1488,6 +1488,25 @@ struct ib_rdmacg_object { 
#endif

};



#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING

struct ib_ucontext_per_mm {

	struct ib_ucontext *context;



	struct rb_root_cached umem_tree;

	/*

	 * Protects .umem_rbroot and tree, as well as odp_mrs_count and

	 * mmu notifiers registration.

	 */

	struct rw_semaphore umem_rwsem;



	struct mmu_notifier mn;

	atomic_t notifier_count;

	/* A list of umems that don't have private mmu notifier counters yet. */

	struct list_head no_private_counters;

	unsigned int odp_mrs_count;

};

#endif



struct ib_ucontext {

	struct ib_device       *device;

	struct ib_uverbs_file  *ufile;
@@ -1502,20 +1521,9 @@ struct ib_ucontext { 


	struct pid             *tgid;

#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING

	struct rb_root_cached   umem_tree;

	/*

	 * Protects .umem_rbroot and tree, as well as odp_mrs_count and

	 * mmu notifiers registration.

	 */

	struct rw_semaphore	umem_rwsem;

	void (*invalidate_range)(struct ib_umem_odp *umem_odp,

				 unsigned long start, unsigned long end);



	struct mmu_notifier	mn;

	atomic_t		notifier_count;

	/* A list of umems that don't have private mmu notifier counters yet. */

	struct list_head	no_private_counters;

	int                     odp_mrs_count;

	struct ib_ucontext_per_mm per_mm;

#endif



	struct ib_rdmacg_object	cg_obj;