[PATCH hmm 05/15] RDMA/odp: Use mmu_range_notifier_insert()
Jason Gunthorpe
jgg at ziepe.ca
Tue Oct 15 18:12:32 UTC 2019
From: Jason Gunthorpe <jgg at mellanox.com>
Replace the internal interval tree based mmu notifier with the new common
mmu_range_notifier_insert() API. This removes a lot of code and fixes a
deadlock that can be triggered in ODP:
zap_page_range()
mmu_notifier_invalidate_range_start()
[..]
ib_umem_notifier_invalidate_range_start()
down_read(&per_mm->umem_rwsem)
unmap_single_vma()
[..]
__split_huge_page_pmd()
mmu_notifier_invalidate_range_start()
[..]
ib_umem_notifier_invalidate_range_start()
down_read(&per_mm->umem_rwsem) // DEADLOCK
mmu_notifier_invalidate_range_end()
up_read(&per_mm->umem_rwsem)
mmu_notifier_invalidate_range_end()
up_read(&per_mm->umem_rwsem)
The umem_rwsem is held across the range_start/end as the ODP algorithm for
invalidate_range_end cannot tolerate changes to the interval
tree. However, due to the nested invalidation regions the second
down_read() can deadlock if there are competing writers. The new core code
provides an alternative scheme to solve this problem.
Fixes: ca748c39ea3f ("RDMA/umem: Get rid of per_mm->notifier_count")
Signed-off-by: Jason Gunthorpe <jgg at mellanox.com>
---
drivers/infiniband/core/device.c | 1 -
drivers/infiniband/core/umem_odp.c | 288 +++------------------------
drivers/infiniband/hw/mlx5/mlx5_ib.h | 7 +-
drivers/infiniband/hw/mlx5/mr.c | 3 +-
drivers/infiniband/hw/mlx5/odp.c | 48 ++---
include/rdma/ib_umem_odp.h | 65 ++----
include/rdma/ib_verbs.h | 2 -
7 files changed, 67 insertions(+), 347 deletions(-)
diff --git a/drivers/infiniband/core/device.c b/drivers/infiniband/core/device.c
index 2dd2cfe9b56136..ac7924b3c73abe 100644
--- a/drivers/infiniband/core/device.c
+++ b/drivers/infiniband/core/device.c
@@ -2617,7 +2617,6 @@ void ib_set_device_ops(struct ib_device *dev, const struct ib_device_ops *ops)
SET_DEVICE_OP(dev_ops, get_vf_config);
SET_DEVICE_OP(dev_ops, get_vf_stats);
SET_DEVICE_OP(dev_ops, init_port);
- SET_DEVICE_OP(dev_ops, invalidate_range);
SET_DEVICE_OP(dev_ops, iw_accept);
SET_DEVICE_OP(dev_ops, iw_add_ref);
SET_DEVICE_OP(dev_ops, iw_connect);
diff --git a/drivers/infiniband/core/umem_odp.c b/drivers/infiniband/core/umem_odp.c
index d7d5fadf0899ad..6132b8127e8435 100644
--- a/drivers/infiniband/core/umem_odp.c
+++ b/drivers/infiniband/core/umem_odp.c
@@ -48,197 +48,32 @@
#include "uverbs.h"
-static void ib_umem_notifier_start_account(struct ib_umem_odp *umem_odp)
-{
- mutex_lock(&umem_odp->umem_mutex);
- if (umem_odp->notifiers_count++ == 0)
- /*
- * Initialize the completion object for waiting on
- * notifiers. Since notifier_count is zero, no one should be
- * waiting right now.
- */
- reinit_completion(&umem_odp->notifier_completion);
- mutex_unlock(&umem_odp->umem_mutex);
-}
-
-static void ib_umem_notifier_end_account(struct ib_umem_odp *umem_odp)
-{
- mutex_lock(&umem_odp->umem_mutex);
- /*
- * This sequence increase will notify the QP page fault that the page
- * that is going to be mapped in the spte could have been freed.
- */
- ++umem_odp->notifiers_seq;
- if (--umem_odp->notifiers_count == 0)
- complete_all(&umem_odp->notifier_completion);
- mutex_unlock(&umem_odp->umem_mutex);
-}
-
-static void ib_umem_notifier_release(struct mmu_notifier *mn,
- struct mm_struct *mm)
-{
- struct ib_ucontext_per_mm *per_mm =
- container_of(mn, struct ib_ucontext_per_mm, mn);
- struct rb_node *node;
-
- down_read(&per_mm->umem_rwsem);
- if (!per_mm->mn.users)
- goto out;
-
- for (node = rb_first_cached(&per_mm->umem_tree); node;
- node = rb_next(node)) {
- struct ib_umem_odp *umem_odp =
- rb_entry(node, struct ib_umem_odp, interval_tree.rb);
-
- /*
- * Increase the number of notifiers running, to prevent any
- * further fault handling on this MR.
- */
- ib_umem_notifier_start_account(umem_odp);
- complete_all(&umem_odp->notifier_completion);
- umem_odp->umem.ibdev->ops.invalidate_range(
- umem_odp, ib_umem_start(umem_odp),
- ib_umem_end(umem_odp));
- }
-
-out:
- up_read(&per_mm->umem_rwsem);
-}
-
-static int invalidate_range_start_trampoline(struct ib_umem_odp *item,
- u64 start, u64 end, void *cookie)
-{
- ib_umem_notifier_start_account(item);
- item->umem.ibdev->ops.invalidate_range(item, start, end);
- return 0;
-}
-
-static int ib_umem_notifier_invalidate_range_start(struct mmu_notifier *mn,
- const struct mmu_notifier_range *range)
-{
- struct ib_ucontext_per_mm *per_mm =
- container_of(mn, struct ib_ucontext_per_mm, mn);
- int rc;
-
- if (mmu_notifier_range_blockable(range))
- down_read(&per_mm->umem_rwsem);
- else if (!down_read_trylock(&per_mm->umem_rwsem))
- return -EAGAIN;
-
- if (!per_mm->mn.users) {
- up_read(&per_mm->umem_rwsem);
- /*
- * At this point users is permanently zero and visible to this
- * CPU without a lock, that fact is relied on to skip the unlock
- * in range_end.
- */
- return 0;
- }
-
- rc = rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start,
- range->end,
- invalidate_range_start_trampoline,
- mmu_notifier_range_blockable(range),
- NULL);
- if (rc)
- up_read(&per_mm->umem_rwsem);
- return rc;
-}
-
-static int invalidate_range_end_trampoline(struct ib_umem_odp *item, u64 start,
- u64 end, void *cookie)
-{
- ib_umem_notifier_end_account(item);
- return 0;
-}
-
-static void ib_umem_notifier_invalidate_range_end(struct mmu_notifier *mn,
- const struct mmu_notifier_range *range)
-{
- struct ib_ucontext_per_mm *per_mm =
- container_of(mn, struct ib_ucontext_per_mm, mn);
-
- if (unlikely(!per_mm->mn.users))
- return;
-
- rbt_ib_umem_for_each_in_range(&per_mm->umem_tree, range->start,
- range->end,
- invalidate_range_end_trampoline, true, NULL);
- up_read(&per_mm->umem_rwsem);
-}
-
-static struct mmu_notifier *ib_umem_alloc_notifier(struct mm_struct *mm)
-{
- struct ib_ucontext_per_mm *per_mm;
-
- per_mm = kzalloc(sizeof(*per_mm), GFP_KERNEL);
- if (!per_mm)
- return ERR_PTR(-ENOMEM);
-
- per_mm->umem_tree = RB_ROOT_CACHED;
- init_rwsem(&per_mm->umem_rwsem);
-
- WARN_ON(mm != current->mm);
- rcu_read_lock();
- per_mm->tgid = get_task_pid(current->group_leader, PIDTYPE_PID);
- rcu_read_unlock();
- return &per_mm->mn;
-}
-
-static void ib_umem_free_notifier(struct mmu_notifier *mn)
-{
- struct ib_ucontext_per_mm *per_mm =
- container_of(mn, struct ib_ucontext_per_mm, mn);
-
- WARN_ON(!RB_EMPTY_ROOT(&per_mm->umem_tree.rb_root));
-
- put_pid(per_mm->tgid);
- kfree(per_mm);
-}
-
-static const struct mmu_notifier_ops ib_umem_notifiers = {
- .release = ib_umem_notifier_release,
- .invalidate_range_start = ib_umem_notifier_invalidate_range_start,
- .invalidate_range_end = ib_umem_notifier_invalidate_range_end,
- .alloc_notifier = ib_umem_alloc_notifier,
- .free_notifier = ib_umem_free_notifier,
-};
-
static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp)
{
- struct ib_ucontext_per_mm *per_mm;
- struct mmu_notifier *mn;
int ret;
umem_odp->umem.is_odp = 1;
+ mutex_init(&umem_odp->umem_mutex);
+
if (!umem_odp->is_implicit_odp) {
size_t page_size = 1UL << umem_odp->page_shift;
+ unsigned long start;
+ unsigned long end;
size_t pages;
- umem_odp->interval_tree.start =
- ALIGN_DOWN(umem_odp->umem.address, page_size);
+ start = ALIGN_DOWN(umem_odp->umem.address, page_size);
if (check_add_overflow(umem_odp->umem.address,
(unsigned long)umem_odp->umem.length,
- &umem_odp->interval_tree.last))
+ &end))
return -EOVERFLOW;
- umem_odp->interval_tree.last =
- ALIGN(umem_odp->interval_tree.last, page_size);
- if (unlikely(umem_odp->interval_tree.last < page_size))
+ end = ALIGN(end, page_size);
+ if (unlikely(end < page_size))
return -EOVERFLOW;
- pages = (umem_odp->interval_tree.last -
- umem_odp->interval_tree.start) >>
- umem_odp->page_shift;
+ pages = (end - start) >> umem_odp->page_shift;
if (!pages)
return -EINVAL;
- /*
- * Note that the representation of the intervals in the
- * interval tree considers the ending point as contained in
- * the interval.
- */
- umem_odp->interval_tree.last--;
-
umem_odp->page_list = kvcalloc(
pages, sizeof(*umem_odp->page_list), GFP_KERNEL);
if (!umem_odp->page_list)
@@ -250,26 +85,15 @@ static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp)
ret = -ENOMEM;
goto out_page_list;
}
- }
- mn = mmu_notifier_get(&ib_umem_notifiers, umem_odp->umem.owning_mm);
- if (IS_ERR(mn)) {
- ret = PTR_ERR(mn);
- goto out_dma_list;
- }
- umem_odp->per_mm = per_mm =
- container_of(mn, struct ib_ucontext_per_mm, mn);
-
- mutex_init(&umem_odp->umem_mutex);
- init_completion(&umem_odp->notifier_completion);
+ ret = mmu_range_notifier_insert(&umem_odp->notifier, start,
+ end - start, current->mm);
+ if (ret)
+ goto out_dma_list;
- if (!umem_odp->is_implicit_odp) {
- down_write(&per_mm->umem_rwsem);
- interval_tree_insert(&umem_odp->interval_tree,
- &per_mm->umem_tree);
- up_write(&per_mm->umem_rwsem);
+ umem_odp->tgid =
+ get_task_pid(current->group_leader, PIDTYPE_PID);
}
- mmgrab(umem_odp->umem.owning_mm);
return 0;
@@ -290,8 +114,8 @@ static inline int ib_init_umem_odp(struct ib_umem_odp *umem_odp)
* @udata: udata from the syscall being used to create the umem
* @access: ib_reg_mr access flags
*/
-struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
- int access)
+struct ib_umem_odp *
+ib_umem_odp_alloc_implicit(struct ib_udata *udata, int access)
{
struct ib_ucontext *context =
container_of(udata, struct uverbs_attr_bundle, driver_udata)
@@ -305,8 +129,6 @@ struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
if (!context)
return ERR_PTR(-EIO);
- if (WARN_ON_ONCE(!context->device->ops.invalidate_range))
- return ERR_PTR(-EINVAL);
umem_odp = kzalloc(sizeof(*umem_odp), GFP_KERNEL);
if (!umem_odp)
@@ -336,8 +158,9 @@ EXPORT_SYMBOL(ib_umem_odp_alloc_implicit);
* @addr: The starting userspace VA
* @size: The length of the userspace VA
*/
-struct ib_umem_odp *ib_umem_odp_alloc_child(struct ib_umem_odp *root,
- unsigned long addr, size_t size)
+struct ib_umem_odp *
+ib_umem_odp_alloc_child(struct ib_umem_odp *root, unsigned long addr,
+ size_t size, const struct mmu_range_notifier_ops *ops)
{
/*
* Caller must ensure that root cannot be freed during the call to
@@ -360,6 +183,7 @@ struct ib_umem_odp *ib_umem_odp_alloc_child(struct ib_umem_odp *root,
umem->writable = root->umem.writable;
umem->owning_mm = root->umem.owning_mm;
odp_data->page_shift = PAGE_SHIFT;
+ odp_data->notifier.ops = ops;
ret = ib_init_umem_odp(odp_data);
if (ret) {
@@ -383,7 +207,8 @@ EXPORT_SYMBOL(ib_umem_odp_alloc_child);
* conjunction with MMU notifiers.
*/
struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
- size_t size, int access)
+ size_t size, int access,
+ const struct mmu_range_notifier_ops *ops)
{
struct ib_umem_odp *umem_odp;
struct ib_ucontext *context;
@@ -398,8 +223,7 @@ struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
if (!context)
return ERR_PTR(-EIO);
- if (WARN_ON_ONCE(!(access & IB_ACCESS_ON_DEMAND)) ||
- WARN_ON_ONCE(!context->device->ops.invalidate_range))
+ if (WARN_ON_ONCE(!(access & IB_ACCESS_ON_DEMAND)))
return ERR_PTR(-EINVAL);
umem_odp = kzalloc(sizeof(struct ib_umem_odp), GFP_KERNEL);
@@ -411,6 +235,7 @@ struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
umem_odp->umem.address = addr;
umem_odp->umem.writable = ib_access_writable(access);
umem_odp->umem.owning_mm = mm = current->mm;
+ umem_odp->notifier.ops = ops;
umem_odp->page_shift = PAGE_SHIFT;
if (access & IB_ACCESS_HUGETLB) {
@@ -442,8 +267,6 @@ EXPORT_SYMBOL(ib_umem_odp_get);
void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
{
- struct ib_ucontext_per_mm *per_mm = umem_odp->per_mm;
-
/*
* Ensure that no more pages are mapped in the umem.
*
@@ -455,28 +278,11 @@ void ib_umem_odp_release(struct ib_umem_odp *umem_odp)
ib_umem_odp_unmap_dma_pages(umem_odp, ib_umem_start(umem_odp),
ib_umem_end(umem_odp));
mutex_unlock(&umem_odp->umem_mutex);
+ mmu_range_notifier_remove(&umem_odp->notifier);
kvfree(umem_odp->dma_list);
kvfree(umem_odp->page_list);
+ put_pid(umem_odp->tgid);
}
-
- down_write(&per_mm->umem_rwsem);
- if (!umem_odp->is_implicit_odp) {
- interval_tree_remove(&umem_odp->interval_tree,
- &per_mm->umem_tree);
- complete_all(&umem_odp->notifier_completion);
- }
- /*
- * NOTE! mmu_notifier_unregister() can happen between a start/end
- * callback, resulting in a missing end, and thus an unbalanced
- * lock. This doesn't really matter to us since we are about to kfree
- * the memory that holds the lock, however LOCKDEP doesn't like this.
- * Thus we call the mmu_notifier_put under the rwsem and test the
- * internal users count to reliably see if we are past this point.
- */
- mmu_notifier_put(&per_mm->mn);
- up_write(&per_mm->umem_rwsem);
-
- mmdrop(umem_odp->umem.owning_mm);
kfree(umem_odp);
}
EXPORT_SYMBOL(ib_umem_odp_release);
@@ -501,7 +307,7 @@ EXPORT_SYMBOL(ib_umem_odp_release);
*/
static int ib_umem_odp_map_dma_single_page(
struct ib_umem_odp *umem_odp,
- int page_index,
+ unsigned int page_index,
struct page *page,
u64 access_mask,
unsigned long current_seq)
@@ -510,12 +316,7 @@ static int ib_umem_odp_map_dma_single_page(
dma_addr_t dma_addr;
int ret = 0;
- /*
- * Note: we avoid writing if seq is different from the initial seq, to
- * handle case of a racing notifier. This check also allows us to bail
- * early if we have a notifier running in parallel with us.
- */
- if (ib_umem_mmu_notifier_retry(umem_odp, current_seq)) {
+ if (mmu_range_check_retry(&umem_odp->notifier, current_seq)) {
ret = -EAGAIN;
goto out;
}
@@ -618,7 +419,7 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 user_virt,
* existing beyond the lifetime of the originating process.. Presumably
* mmget_not_zero will fail in this case.
*/
- owning_process = get_pid_task(umem_odp->per_mm->tgid, PIDTYPE_PID);
+ owning_process = get_pid_task(umem_odp->tgid, PIDTYPE_PID);
if (!owning_process || !mmget_not_zero(owning_mm)) {
ret = -EINVAL;
goto out_put_task;
@@ -762,32 +563,3 @@ void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 virt,
}
}
EXPORT_SYMBOL(ib_umem_odp_unmap_dma_pages);
-
-/* @last is not a part of the interval. See comment for function
- * node_last.
- */
-int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
- u64 start, u64 last,
- umem_call_back cb,
- bool blockable,
- void *cookie)
-{
- int ret_val = 0;
- struct interval_tree_node *node, *next;
- struct ib_umem_odp *umem;
-
- if (unlikely(start == last))
- return ret_val;
-
- for (node = interval_tree_iter_first(root, start, last - 1);
- node; node = next) {
- /* TODO move the blockable decision up to the callback */
- if (!blockable)
- return -EAGAIN;
- next = interval_tree_iter_next(node, start, last - 1);
- umem = container_of(node, struct ib_umem_odp, interval_tree);
- ret_val = cb(umem, start, last, cookie) || ret_val;
- }
-
- return ret_val;
-}
diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h
index f61d4005c6c379..c719f08b351670 100644
--- a/drivers/infiniband/hw/mlx5/mlx5_ib.h
+++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h
@@ -1263,8 +1263,6 @@ int mlx5_ib_odp_init_one(struct mlx5_ib_dev *ibdev);
void mlx5_ib_odp_cleanup_one(struct mlx5_ib_dev *ibdev);
int __init mlx5_ib_odp_init(void);
void mlx5_ib_odp_cleanup(void);
-void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
- unsigned long end);
void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent);
void mlx5_odp_populate_klm(struct mlx5_klm *pklm, size_t offset,
size_t nentries, struct mlx5_ib_mr *mr, int flags);
@@ -1294,11 +1292,10 @@ mlx5_ib_advise_mr_prefetch(struct ib_pd *pd,
{
return -EOPNOTSUPP;
}
-static inline void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp,
- unsigned long start,
- unsigned long end){};
#endif /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
+extern const struct mmu_range_notifier_ops mlx5_mn_ops;
+
/* Needed for rep profile */
void __mlx5_ib_remove(struct mlx5_ib_dev *dev,
const struct mlx5_ib_profile *profile,
diff --git a/drivers/infiniband/hw/mlx5/mr.c b/drivers/infiniband/hw/mlx5/mr.c
index 199f7959aaa510..fbe31830b22807 100644
--- a/drivers/infiniband/hw/mlx5/mr.c
+++ b/drivers/infiniband/hw/mlx5/mr.c
@@ -743,7 +743,8 @@ static int mr_umem_get(struct mlx5_ib_dev *dev, struct ib_udata *udata,
if (access_flags & IB_ACCESS_ON_DEMAND) {
struct ib_umem_odp *odp;
- odp = ib_umem_odp_get(udata, start, length, access_flags);
+ odp = ib_umem_odp_get(udata, start, length, access_flags,
+ &mlx5_mn_ops);
if (IS_ERR(odp)) {
mlx5_ib_dbg(dev, "umem get failed (%ld)\n",
PTR_ERR(odp));
diff --git a/drivers/infiniband/hw/mlx5/odp.c b/drivers/infiniband/hw/mlx5/odp.c
index fd2306aff78ad7..98b1009c5c0e00 100644
--- a/drivers/infiniband/hw/mlx5/odp.c
+++ b/drivers/infiniband/hw/mlx5/odp.c
@@ -246,16 +246,23 @@ static void destroy_unused_implicit_child_mr(struct mlx5_ib_mr *mr)
xa_unlock(&imr->implicit_children);
}
-void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
- unsigned long end)
+static bool mlx5_ib_invalidate_range(struct mmu_range_notifier *mrn,
+ const struct mmu_notifier_range *range)
{
+ struct ib_umem_odp *umem_odp =
+ container_of(mrn, struct ib_umem_odp, notifier);
struct mlx5_ib_mr *mr;
const u64 umr_block_mask = (MLX5_UMR_MTT_ALIGNMENT /
sizeof(struct mlx5_mtt)) - 1;
u64 idx = 0, blk_start_idx = 0;
+ unsigned long start;
+ unsigned long end;
int in_block = 0;
u64 addr;
+ if (!mmu_notifier_range_blockable(range))
+ return false;
+
mutex_lock(&umem_odp->umem_mutex);
/*
* If npages is zero then umem_odp->private may not be setup yet. This
@@ -265,8 +272,8 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
goto out;
mr = umem_odp->private;
- start = max_t(u64, ib_umem_start(umem_odp), start);
- end = min_t(u64, ib_umem_end(umem_odp), end);
+ start = max_t(u64, ib_umem_start(umem_odp), range->start);
+ end = min_t(u64, ib_umem_end(umem_odp), range->end);
/*
* Iteration one - zap the HW's MTTs. The notifiers_count ensures that
@@ -317,8 +324,13 @@ void mlx5_ib_invalidate_range(struct ib_umem_odp *umem_odp, unsigned long start,
destroy_unused_implicit_child_mr(mr);
out:
mutex_unlock(&umem_odp->umem_mutex);
+ return true;
}
+const struct mmu_range_notifier_ops mlx5_mn_ops = {
+ .invalidate = mlx5_ib_invalidate_range,
+};
+
void mlx5_ib_internal_fill_odp_caps(struct mlx5_ib_dev *dev)
{
struct ib_odp_caps *caps = &dev->odp_caps;
@@ -419,7 +431,7 @@ static struct mlx5_ib_mr *implicit_get_child_mr(struct mlx5_ib_mr *imr,
odp = ib_umem_odp_alloc_child(to_ib_umem_odp(imr->umem),
idx * MLX5_IMR_MTT_SIZE,
- MLX5_IMR_MTT_SIZE);
+ MLX5_IMR_MTT_SIZE, &mlx5_mn_ops);
if (IS_ERR(odp))
return ERR_CAST(odp);
@@ -605,8 +617,9 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
u64 user_va, size_t bcnt, u32 *bytes_mapped,
u32 flags)
{
- int current_seq, page_shift, ret, np;
+ int page_shift, ret, np;
bool downgrade = flags & MLX5_PF_FLAGS_DOWNGRADE;
+ unsigned long current_seq;
u64 access_mask;
u64 start_idx, page_mask;
@@ -618,12 +631,7 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
if (odp->umem.writable && !downgrade)
access_mask |= ODP_WRITE_ALLOWED_BIT;
- current_seq = READ_ONCE(odp->notifiers_seq);
- /*
- * Ensure the sequence number is valid for some time before we call
- * gup.
- */
- smp_rmb();
+ current_seq = mmu_range_read_begin(&odp->notifier);
np = ib_umem_odp_map_dma_pages(odp, user_va, bcnt, access_mask,
current_seq);
@@ -631,7 +639,7 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
return np;
mutex_lock(&odp->umem_mutex);
- if (!ib_umem_mmu_notifier_retry(odp, current_seq)) {
+ if (!mmu_range_read_retry(&odp->notifier, current_seq)) {
/*
* No need to check whether the MTTs really belong to
* this MR, since ib_umem_odp_map_dma_pages already
@@ -661,19 +669,6 @@ static int pagefault_real_mr(struct mlx5_ib_mr *mr, struct ib_umem_odp *odp,
return np << (page_shift - PAGE_SHIFT);
out:
- if (ret == -EAGAIN) {
- unsigned long timeout = msecs_to_jiffies(MMU_NOTIFIER_TIMEOUT);
-
- if (!wait_for_completion_timeout(&odp->notifier_completion,
- timeout)) {
- mlx5_ib_warn(
- mr->dev,
- "timeout waiting for mmu notifier. seq %d against %d. notifiers_count=%d\n",
- current_seq, odp->notifiers_seq,
- odp->notifiers_count);
- }
- }
-
return ret;
}
@@ -1614,7 +1609,6 @@ void mlx5_odp_init_mr_cache_entry(struct mlx5_cache_ent *ent)
static const struct ib_device_ops mlx5_ib_dev_odp_ops = {
.advise_mr = mlx5_ib_advise_mr,
- .invalidate_range = mlx5_ib_invalidate_range,
};
int mlx5_ib_odp_init_one(struct mlx5_ib_dev *dev)
diff --git a/include/rdma/ib_umem_odp.h b/include/rdma/ib_umem_odp.h
index 09b0e4494986a9..98ed5435afccd9 100644
--- a/include/rdma/ib_umem_odp.h
+++ b/include/rdma/ib_umem_odp.h
@@ -35,11 +35,11 @@
#include <rdma/ib_umem.h>
#include <rdma/ib_verbs.h>
-#include <linux/interval_tree.h>
struct ib_umem_odp {
struct ib_umem umem;
- struct ib_ucontext_per_mm *per_mm;
+ struct mmu_range_notifier notifier;
+ struct pid *tgid;
/*
* An array of the pages included in the on-demand paging umem.
@@ -62,13 +62,8 @@ struct ib_umem_odp {
struct mutex umem_mutex;
void *private; /* for the HW driver to use. */
- int notifiers_seq;
- int notifiers_count;
int npages;
- /* Tree tracking */
- struct interval_tree_node interval_tree;
-
/*
* An implicit odp umem cannot be DMA mapped, has 0 length, and serves
* only as an anchor for the driver to hold onto the per_mm. FIXME:
@@ -77,7 +72,6 @@ struct ib_umem_odp {
*/
bool is_implicit_odp;
- struct completion notifier_completion;
unsigned int page_shift;
};
@@ -89,13 +83,13 @@ static inline struct ib_umem_odp *to_ib_umem_odp(struct ib_umem *umem)
/* Returns the first page of an ODP umem. */
static inline unsigned long ib_umem_start(struct ib_umem_odp *umem_odp)
{
- return umem_odp->interval_tree.start;
+ return umem_odp->notifier.interval_tree.start;
}
/* Returns the address of the page after the last one of an ODP umem. */
static inline unsigned long ib_umem_end(struct ib_umem_odp *umem_odp)
{
- return umem_odp->interval_tree.last + 1;
+ return umem_odp->notifier.interval_tree.last + 1;
}
static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
@@ -119,21 +113,14 @@ static inline size_t ib_umem_odp_num_pages(struct ib_umem_odp *umem_odp)
#ifdef CONFIG_INFINIBAND_ON_DEMAND_PAGING
-struct ib_ucontext_per_mm {
- struct mmu_notifier mn;
- struct pid *tgid;
-
- struct rb_root_cached umem_tree;
- /* Protects umem_tree */
- struct rw_semaphore umem_rwsem;
-};
-
struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata, unsigned long addr,
- size_t size, int access);
+ size_t size, int access,
+ const struct mmu_range_notifier_ops *ops);
struct ib_umem_odp *ib_umem_odp_alloc_implicit(struct ib_udata *udata,
int access);
-struct ib_umem_odp *ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem,
- unsigned long addr, size_t size);
+struct ib_umem_odp *
+ib_umem_odp_alloc_child(struct ib_umem_odp *root_umem, unsigned long addr,
+ size_t size, const struct mmu_range_notifier_ops *ops);
void ib_umem_odp_release(struct ib_umem_odp *umem_odp);
int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
@@ -143,39 +130,11 @@ int ib_umem_odp_map_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
void ib_umem_odp_unmap_dma_pages(struct ib_umem_odp *umem_odp, u64 start_offset,
u64 bound);
-typedef int (*umem_call_back)(struct ib_umem_odp *item, u64 start, u64 end,
- void *cookie);
-/*
- * Call the callback on each ib_umem in the range. Returns the logical or of
- * the return values of the functions called.
- */
-int rbt_ib_umem_for_each_in_range(struct rb_root_cached *root,
- u64 start, u64 end,
- umem_call_back cb,
- bool blockable, void *cookie);
-
-static inline int ib_umem_mmu_notifier_retry(struct ib_umem_odp *umem_odp,
- unsigned long mmu_seq)
-{
- /*
- * This code is strongly based on the KVM code from
- * mmu_notifier_retry. Should be called with
- * the relevant locks taken (umem_odp->umem_mutex
- * and the ucontext umem_mutex semaphore locked for read).
- */
-
- if (unlikely(umem_odp->notifiers_count))
- return 1;
- if (umem_odp->notifiers_seq != mmu_seq)
- return 1;
- return 0;
-}
-
#else /* CONFIG_INFINIBAND_ON_DEMAND_PAGING */
-static inline struct ib_umem_odp *ib_umem_odp_get(struct ib_udata *udata,
- unsigned long addr,
- size_t size, int access)
+static inline struct ib_umem_odp *
+ib_umem_odp_get(struct ib_udata *udata, unsigned long addr, size_t size,
+ int access, const struct mmu_range_notifier_ops *ops)
{
return ERR_PTR(-EINVAL);
}
diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 6a47ba85c54c11..2c30c859ae0d13 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h
@@ -2422,8 +2422,6 @@ struct ib_device_ops {
u64 iova);
int (*unmap_fmr)(struct list_head *fmr_list);
int (*dealloc_fmr)(struct ib_fmr *fmr);
- void (*invalidate_range)(struct ib_umem_odp *umem_odp,
- unsigned long start, unsigned long end);
int (*attach_mcast)(struct ib_qp *qp, union ib_gid *gid, u16 lid);
int (*detach_mcast)(struct ib_qp *qp, union ib_gid *gid, u16 lid);
struct ib_xrcd *(*alloc_xrcd)(struct ib_device *device,
--
2.23.0
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