From: Bob Pearson <rpearsonhpe@gmail.com>
Date: Thu, 3 Mar 2022 18:08:04 -0600
Subject: RDMA/rxe: Replace red-black trees by xarrays
Patch-mainline: v5.18-rc1
Git-commit: 3225717f6dfa29a6f03629b7a7f8492e1521d06d
References: jsc#PED-1111
Currently the rxe driver uses red-black trees to add indices to the rxe
object pools. Linux xarrays provide a better way to implement the same
functionality for indices. This patch replaces red-black trees by xarrays
for pool objects. Since xarrays already have a spinlock use that in place
of the pool rwlock. Make sure that all changes in the xarray(index) and
kref(ref counnt) occur atomically.
Link: https://lore.kernel.org/r/20220304000808.225811-9-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/infiniband/sw/rxe/rxe.c | 80 +-----------
drivers/infiniband/sw/rxe/rxe_mr.c | 1
drivers/infiniband/sw/rxe/rxe_mw.c | 8 -
drivers/infiniband/sw/rxe/rxe_pool.c | 221 +++++++++-------------------------
drivers/infiniband/sw/rxe/rxe_pool.h | 43 +-----
drivers/infiniband/sw/rxe/rxe_verbs.c | 12 -
6 files changed, 85 insertions(+), 280 deletions(-)
--- a/drivers/infiniband/sw/rxe/rxe.c
+++ b/drivers/infiniband/sw/rxe/rxe.c
@@ -114,75 +114,26 @@ static void rxe_init_ports(struct rxe_de
}
/* init pools of managed objects */
-static int rxe_init_pools(struct rxe_dev *rxe)
+static void rxe_init_pools(struct rxe_dev *rxe)
{
- int err;
-
- err = rxe_pool_init(rxe, &rxe->uc_pool, RXE_TYPE_UC);
- if (err)
- goto err1;
-
- err = rxe_pool_init(rxe, &rxe->pd_pool, RXE_TYPE_PD);
- if (err)
- goto err2;
-
- err = rxe_pool_init(rxe, &rxe->ah_pool, RXE_TYPE_AH);
- if (err)
- goto err3;
-
- err = rxe_pool_init(rxe, &rxe->srq_pool, RXE_TYPE_SRQ);
- if (err)
- goto err4;
-
- err = rxe_pool_init(rxe, &rxe->qp_pool, RXE_TYPE_QP);
- if (err)
- goto err5;
-
- err = rxe_pool_init(rxe, &rxe->cq_pool, RXE_TYPE_CQ);
- if (err)
- goto err6;
-
- err = rxe_pool_init(rxe, &rxe->mr_pool, RXE_TYPE_MR);
- if (err)
- goto err7;
-
- err = rxe_pool_init(rxe, &rxe->mw_pool, RXE_TYPE_MW);
- if (err)
- goto err8;
-
- return 0;
-
-err8:
- rxe_pool_cleanup(&rxe->mr_pool);
-err7:
- rxe_pool_cleanup(&rxe->cq_pool);
-err6:
- rxe_pool_cleanup(&rxe->qp_pool);
-err5:
- rxe_pool_cleanup(&rxe->srq_pool);
-err4:
- rxe_pool_cleanup(&rxe->ah_pool);
-err3:
- rxe_pool_cleanup(&rxe->pd_pool);
-err2:
- rxe_pool_cleanup(&rxe->uc_pool);
-err1:
- return err;
+ rxe_pool_init(rxe, &rxe->uc_pool, RXE_TYPE_UC);
+ rxe_pool_init(rxe, &rxe->pd_pool, RXE_TYPE_PD);
+ rxe_pool_init(rxe, &rxe->ah_pool, RXE_TYPE_AH);
+ rxe_pool_init(rxe, &rxe->srq_pool, RXE_TYPE_SRQ);
+ rxe_pool_init(rxe, &rxe->qp_pool, RXE_TYPE_QP);
+ rxe_pool_init(rxe, &rxe->cq_pool, RXE_TYPE_CQ);
+ rxe_pool_init(rxe, &rxe->mr_pool, RXE_TYPE_MR);
+ rxe_pool_init(rxe, &rxe->mw_pool, RXE_TYPE_MW);
}
/* initialize rxe device state */
-static int rxe_init(struct rxe_dev *rxe)
+static void rxe_init(struct rxe_dev *rxe)
{
- int err;
-
/* init default device parameters */
rxe_init_device_param(rxe);
rxe_init_ports(rxe);
-
- err = rxe_init_pools(rxe);
- if (err)
- return err;
+ rxe_init_pools(rxe);
/* init pending mmap list */
spin_lock_init(&rxe->mmap_offset_lock);
@@ -194,8 +145,6 @@ static int rxe_init(struct rxe_dev *rxe)
rxe->mcg_tree = RB_ROOT;
mutex_init(&rxe->usdev_lock);
-
- return 0;
}
void rxe_set_mtu(struct rxe_dev *rxe, unsigned int ndev_mtu)
@@ -217,12 +166,7 @@ void rxe_set_mtu(struct rxe_dev *rxe, un
*/
int rxe_add(struct rxe_dev *rxe, unsigned int mtu, const char *ibdev_name)
{
- int err;
-
- err = rxe_init(rxe);
- if (err)
- return err;
-
+ rxe_init(rxe);
rxe_set_mtu(rxe, mtu);
return rxe_register_device(rxe, ibdev_name);
--- a/drivers/infiniband/sw/rxe/rxe_mr.c
+++ b/drivers/infiniband/sw/rxe/rxe_mr.c
@@ -691,7 +691,6 @@ int rxe_dereg_mr(struct ib_mr *ibmr, str
mr->state = RXE_MR_STATE_INVALID;
rxe_drop_ref(mr_pd(mr));
- rxe_drop_index(mr);
rxe_drop_ref(mr);
return 0;
--- a/drivers/infiniband/sw/rxe/rxe_mw.c
+++ b/drivers/infiniband/sw/rxe/rxe_mw.c
@@ -20,7 +20,6 @@ int rxe_alloc_mw(struct ib_mw *ibmw, str
return ret;
}
- rxe_add_index(mw);
mw->rkey = ibmw->rkey = (mw->elem.index << 8) | rxe_get_next_key(-1);
mw->state = (mw->ibmw.type == IB_MW_TYPE_2) ?
RXE_MW_STATE_FREE : RXE_MW_STATE_VALID;
@@ -329,10 +328,3 @@ struct rxe_mw *rxe_lookup_mw(struct rxe_
return mw;
}
-
-void rxe_mw_cleanup(struct rxe_pool_elem *elem)
-{
- struct rxe_mw *mw = container_of(elem, typeof(*mw), elem);
-
- rxe_drop_index(mw);
-}
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -22,19 +22,22 @@ static const struct rxe_type_info {
.name = "uc",
.size = sizeof(struct rxe_ucontext),
.elem_offset = offsetof(struct rxe_ucontext, elem),
+ .min_index = 1,
+ .max_index = UINT_MAX,
.max_elem = UINT_MAX,
},
[RXE_TYPE_PD] = {
.name = "pd",
.size = sizeof(struct rxe_pd),
.elem_offset = offsetof(struct rxe_pd, elem),
+ .min_index = 1,
+ .max_index = UINT_MAX,
.max_elem = UINT_MAX,
},
[RXE_TYPE_AH] = {
.name = "ah",
.size = sizeof(struct rxe_ah),
.elem_offset = offsetof(struct rxe_ah, elem),
- .flags = RXE_POOL_INDEX,
.min_index = RXE_MIN_AH_INDEX,
.max_index = RXE_MAX_AH_INDEX,
.max_elem = RXE_MAX_AH_INDEX - RXE_MIN_AH_INDEX + 1,
@@ -43,7 +46,6 @@ static const struct rxe_type_info {
.name = "srq",
.size = sizeof(struct rxe_srq),
.elem_offset = offsetof(struct rxe_srq, elem),
- .flags = RXE_POOL_INDEX,
.min_index = RXE_MIN_SRQ_INDEX,
.max_index = RXE_MAX_SRQ_INDEX,
.max_elem = RXE_MAX_SRQ_INDEX - RXE_MIN_SRQ_INDEX + 1,
@@ -53,7 +55,6 @@ static const struct rxe_type_info {
.size = sizeof(struct rxe_qp),
.elem_offset = offsetof(struct rxe_qp, elem),
.cleanup = rxe_qp_cleanup,
- .flags = RXE_POOL_INDEX,
.min_index = RXE_MIN_QP_INDEX,
.max_index = RXE_MAX_QP_INDEX,
.max_elem = RXE_MAX_QP_INDEX - RXE_MIN_QP_INDEX + 1,
@@ -63,6 +64,8 @@ static const struct rxe_type_info {
.size = sizeof(struct rxe_cq),
.elem_offset = offsetof(struct rxe_cq, elem),
.cleanup = rxe_cq_cleanup,
+ .min_index = 1,
+ .max_index = UINT_MAX,
.max_elem = UINT_MAX,
},
[RXE_TYPE_MR] = {
@@ -70,7 +73,7 @@ static const struct rxe_type_info {
.size = sizeof(struct rxe_mr),
.elem_offset = offsetof(struct rxe_mr, elem),
.cleanup = rxe_mr_cleanup,
- .flags = RXE_POOL_INDEX | RXE_POOL_ALLOC,
+ .flags = RXE_POOL_ALLOC,
.min_index = RXE_MIN_MR_INDEX,
.max_index = RXE_MAX_MR_INDEX,
.max_elem = RXE_MAX_MR_INDEX - RXE_MIN_MR_INDEX + 1,
@@ -79,44 +82,16 @@ static const struct rxe_type_info {
.name = "mw",
.size = sizeof(struct rxe_mw),
.elem_offset = offsetof(struct rxe_mw, elem),
- .cleanup = rxe_mw_cleanup,
- .flags = RXE_POOL_INDEX,
.min_index = RXE_MIN_MW_INDEX,
.max_index = RXE_MAX_MW_INDEX,
.max_elem = RXE_MAX_MW_INDEX - RXE_MIN_MW_INDEX + 1,
},
};
-static int rxe_pool_init_index(struct rxe_pool *pool, u32 max, u32 min)
-{
- int err = 0;
-
- if ((max - min + 1) < pool->max_elem) {
- pr_warn("not enough indices for max_elem\n");
- err = -EINVAL;
- goto out;
- }
-
- pool->index.max_index = max;
- pool->index.min_index = min;
-
- pool->index.table = bitmap_zalloc(max - min + 1, GFP_KERNEL);
- if (!pool->index.table) {
- err = -ENOMEM;
- goto out;
- }
-
-out:
- return err;
-}
-
-int rxe_pool_init(
- struct rxe_dev *rxe,
- struct rxe_pool *pool,
- enum rxe_elem_type type)
+void rxe_pool_init(struct rxe_dev *rxe, struct rxe_pool *pool,
+ enum rxe_elem_type type)
{
const struct rxe_type_info *info = &rxe_type_info[type];
- int err = 0;
memset(pool, 0, sizeof(*pool));
@@ -131,111 +106,31 @@ int rxe_pool_init(
atomic_set(&pool->num_elem, 0);
- rwlock_init(&pool->pool_lock);
-
- if (pool->flags & RXE_POOL_INDEX) {
- pool->index.tree = RB_ROOT;
- err = rxe_pool_init_index(pool, info->max_index,
- info->min_index);
- if (err)
- goto out;
- }
-
-out:
- return err;
+ xa_init_flags(&pool->xa, XA_FLAGS_ALLOC);
+ pool->limit.min = info->min_index;
+ pool->limit.max = info->max_index;
}
void rxe_pool_cleanup(struct rxe_pool *pool)
{
- if (atomic_read(&pool->num_elem) > 0)
- pr_warn("%s pool destroyed with unfree'd elem\n",
- pool->name);
-
- if (pool->flags & RXE_POOL_INDEX)
- bitmap_free(pool->index.table);
-}
-
-static u32 alloc_index(struct rxe_pool *pool)
-{
- u32 index;
- u32 range = pool->index.max_index - pool->index.min_index + 1;
-
- index = find_next_zero_bit(pool->index.table, range, pool->index.last);
- if (index >= range)
- index = find_first_zero_bit(pool->index.table, range);
-
- WARN_ON_ONCE(index >= range);
- set_bit(index, pool->index.table);
- pool->index.last = index;
- return index + pool->index.min_index;
-}
-
-static int rxe_insert_index(struct rxe_pool *pool, struct rxe_pool_elem *new)
-{
- struct rb_node **link = &pool->index.tree.rb_node;
- struct rb_node *parent = NULL;
- struct rxe_pool_elem *elem;
-
- while (*link) {
- parent = *link;
- elem = rb_entry(parent, struct rxe_pool_elem, index_node);
-
- if (elem->index == new->index) {
- pr_warn("element already exists!\n");
- return -EINVAL;
- }
-
- if (elem->index > new->index)
- link = &(*link)->rb_left;
- else
- link = &(*link)->rb_right;
- }
-
- rb_link_node(&new->index_node, parent, link);
- rb_insert_color(&new->index_node, &pool->index.tree);
-
- return 0;
-}
-
-int __rxe_add_index(struct rxe_pool_elem *elem)
-{
- struct rxe_pool *pool = elem->pool;
- unsigned long flags;
- int err;
-
- write_lock_irqsave(&pool->pool_lock, flags);
- elem->index = alloc_index(pool);
- err = rxe_insert_index(pool, elem);
- write_unlock_irqrestore(&pool->pool_lock, flags);
-
- return err;
-}
-
-void __rxe_drop_index(struct rxe_pool_elem *elem)
-{
- struct rxe_pool *pool = elem->pool;
- unsigned long flags;
-
- write_lock_irqsave(&pool->pool_lock, flags);
- clear_bit(elem->index - pool->index.min_index, pool->index.table);
- rb_erase(&elem->index_node, &pool->index.tree);
- write_unlock_irqrestore(&pool->pool_lock, flags);
+ WARN_ON(!xa_empty(&pool->xa));
}
void *rxe_alloc(struct rxe_pool *pool)
{
struct rxe_pool_elem *elem;
void *obj;
+ int err;
if (WARN_ON(!(pool->flags & RXE_POOL_ALLOC)))
return NULL;
if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
- goto out_cnt;
+ goto err_cnt;
obj = kzalloc(pool->elem_size, GFP_KERNEL);
if (!obj)
- goto out_cnt;
+ goto err_cnt;
elem = (struct rxe_pool_elem *)((u8 *)obj + pool->elem_offset);
@@ -243,78 +138,86 @@ void *rxe_alloc(struct rxe_pool *pool)
elem->obj = obj;
kref_init(&elem->ref_cnt);
+ err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
+ &pool->next, GFP_KERNEL);
+ if (err)
+ goto err_free;
+
return obj;
-out_cnt:
+err_free:
+ kfree(obj);
+err_cnt:
atomic_dec(&pool->num_elem);
return NULL;
}
int __rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_elem *elem)
{
+ int err;
+
if (WARN_ON(pool->flags & RXE_POOL_ALLOC))
return -EINVAL;
if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
- goto out_cnt;
+ goto err_cnt;
elem->pool = pool;
elem->obj = (u8 *)elem - pool->elem_offset;
kref_init(&elem->ref_cnt);
+ err = xa_alloc_cyclic(&pool->xa, &elem->index, elem, pool->limit,
+ &pool->next, GFP_KERNEL);
+ if (err)
+ goto err_cnt;
+
return 0;
-out_cnt:
+err_cnt:
atomic_dec(&pool->num_elem);
return -EINVAL;
}
-void rxe_elem_release(struct kref *kref)
+void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
{
- struct rxe_pool_elem *elem =
- container_of(kref, struct rxe_pool_elem, ref_cnt);
- struct rxe_pool *pool = elem->pool;
+ struct rxe_pool_elem *elem;
+ struct xarray *xa = &pool->xa;
+ unsigned long flags;
void *obj;
- if (pool->cleanup)
- pool->cleanup(elem);
-
- if (pool->flags & RXE_POOL_ALLOC) {
+ xa_lock_irqsave(xa, flags);
+ elem = xa_load(xa, index);
+ if (elem && kref_get_unless_zero(&elem->ref_cnt))
obj = elem->obj;
- kfree(obj);
- }
+ else
+ obj = NULL;
+ xa_unlock_irqrestore(xa, flags);
- atomic_dec(&pool->num_elem);
+ return obj;
}
-void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
+static void rxe_elem_release(struct kref *kref)
{
- struct rxe_pool_elem *elem;
- struct rb_node *node;
- unsigned long flags;
- void *obj;
+ struct rxe_pool_elem *elem = container_of(kref, typeof(*elem), ref_cnt);
+ struct rxe_pool *pool = elem->pool;
- read_lock_irqsave(&pool->pool_lock, flags);
- node = pool->index.tree.rb_node;
+ xa_erase(&pool->xa, elem->index);
- while (node) {
- elem = rb_entry(node, struct rxe_pool_elem, index_node);
+ if (pool->cleanup)
+ pool->cleanup(elem);
- if (elem->index > index)
- node = node->rb_left;
- else if (elem->index < index)
- node = node->rb_right;
- else
- break;
- }
+ if (pool->flags & RXE_POOL_ALLOC)
+ kfree(elem->obj);
- if (node) {
- kref_get(&elem->ref_cnt);
- obj = elem->obj;
- } else {
- obj = NULL;
- }
- read_unlock_irqrestore(&pool->pool_lock, flags);
+ atomic_dec(&pool->num_elem);
+}
- return obj;
+int __rxe_get(struct rxe_pool_elem *elem)
+{
+ return kref_get_unless_zero(&elem->ref_cnt);
+}
+
+int __rxe_put(struct rxe_pool_elem *elem)
+{
+ return kref_put(&elem->ref_cnt, rxe_elem_release);
}
--- a/drivers/infiniband/sw/rxe/rxe_pool.h
+++ b/drivers/infiniband/sw/rxe/rxe_pool.h
@@ -8,8 +8,7 @@
#define RXE_POOL_H
enum rxe_pool_flags {
- RXE_POOL_INDEX = BIT(1),
- RXE_POOL_ALLOC = BIT(2),
+ RXE_POOL_ALLOC = BIT(1),
};
enum rxe_elem_type {
@@ -29,16 +28,12 @@ struct rxe_pool_elem {
void *obj;
struct kref ref_cnt;
struct list_head list;
-
- /* only used if indexed */
- struct rb_node index_node;
u32 index;
};
struct rxe_pool {
struct rxe_dev *rxe;
const char *name;
- rwlock_t pool_lock; /* protects pool add/del/search */
void (*cleanup)(struct rxe_pool_elem *elem);
enum rxe_pool_flags flags;
enum rxe_elem_type type;
@@ -48,21 +43,16 @@ struct rxe_pool {
size_t elem_size;
size_t elem_offset;
- /* only used if indexed */
- struct {
- struct rb_root tree;
- unsigned long *table;
- u32 last;
- u32 max_index;
- u32 min_index;
- } index;
+ struct xarray xa;
+ struct xa_limit limit;
+ u32 next;
};
/* initialize a pool of objects with given limit on
* number of elements. gets parameters from rxe_type_info
* pool elements will be allocated out of a slab cache
*/
-int rxe_pool_init(struct rxe_dev *rxe, struct rxe_pool *pool,
+void rxe_pool_init(struct rxe_dev *rxe, struct rxe_pool *pool,
enum rxe_elem_type type);
/* free resources from object pool */
@@ -76,29 +66,18 @@ int __rxe_add_to_pool(struct rxe_pool *p
#define rxe_add_to_pool(pool, obj) __rxe_add_to_pool(pool, &(obj)->elem)
-/* assign an index to an indexed object and insert object into
- * pool's rb tree
- */
-int __rxe_add_index(struct rxe_pool_elem *elem);
-
-#define rxe_add_index(obj) __rxe_add_index(&(obj)->elem)
-
-/* drop an index and remove object from rb tree */
-void __rxe_drop_index(struct rxe_pool_elem *elem);
-
-#define rxe_drop_index(obj) __rxe_drop_index(&(obj)->elem)
-
/* lookup an indexed object from index. takes a reference on object */
void *rxe_pool_get_index(struct rxe_pool *pool, u32 index);
-/* cleanup an object when all references are dropped */
-void rxe_elem_release(struct kref *kref);
-
/* take a reference on an object */
-#define rxe_add_ref(obj) kref_get(&(obj)->elem.ref_cnt)
+int __rxe_get(struct rxe_pool_elem *elem);
+
+#define rxe_add_ref(obj) __rxe_get(&(obj)->elem)
/* drop a reference on an object */
-#define rxe_drop_ref(obj) kref_put(&(obj)->elem.ref_cnt, rxe_elem_release)
+int __rxe_put(struct rxe_pool_elem *elem);
+
+#define rxe_drop_ref(obj) __rxe_put(&(obj)->elem)
#define rxe_read_ref(obj) kref_read(&(obj)->elem.ref_cnt)
--- a/drivers/infiniband/sw/rxe/rxe_verbs.c
+++ b/drivers/infiniband/sw/rxe/rxe_verbs.c
@@ -181,7 +181,6 @@ static int rxe_create_ah(struct ib_ah *i
return err;
/* create index > 0 */
- rxe_add_index(ah);
ah->ah_num = ah->elem.index;
if (uresp) {
@@ -189,7 +188,6 @@ static int rxe_create_ah(struct ib_ah *i
err = copy_to_user(&uresp->ah_num, &ah->ah_num,
sizeof(uresp->ah_num));
if (err) {
- rxe_drop_index(ah);
rxe_drop_ref(ah);
return -EFAULT;
}
@@ -230,7 +228,6 @@ static int rxe_destroy_ah(struct ib_ah *
{
struct rxe_ah *ah = to_rah(ibah);
- rxe_drop_index(ah);
rxe_drop_ref(ah);
return 0;
}
@@ -438,7 +435,6 @@ static int rxe_create_qp(struct ib_qp *i
if (err)
return err;
- rxe_add_index(qp);
err = rxe_qp_from_init(rxe, qp, pd, init, uresp, ibqp->pd, udata);
if (err)
goto qp_init;
@@ -446,7 +442,6 @@ static int rxe_create_qp(struct ib_qp *i
return 0;
qp_init:
- rxe_drop_index(qp);
rxe_drop_ref(qp);
return err;
}
@@ -501,7 +496,6 @@ static int rxe_destroy_qp(struct ib_qp *
return ret;
rxe_qp_destroy(qp);
- rxe_drop_index(qp);
rxe_drop_ref(qp);
return 0;
}
@@ -908,7 +902,6 @@ static struct ib_mr *rxe_get_dma_mr(stru
if (!mr)
return ERR_PTR(-ENOMEM);
- rxe_add_index(mr);
rxe_add_ref(pd);
rxe_mr_init_dma(pd, access, mr);
@@ -932,7 +925,6 @@ static struct ib_mr *rxe_reg_user_mr(str
goto err2;
}
- rxe_add_index(mr);
rxe_add_ref(pd);
@@ -944,7 +936,6 @@ static struct ib_mr *rxe_reg_user_mr(str
err3:
rxe_drop_ref(pd);
- rxe_drop_index(mr);
rxe_drop_ref(mr);
err2:
return ERR_PTR(err);
@@ -967,8 +958,6 @@ static struct ib_mr *rxe_alloc_mr(struct
goto err1;
}
- rxe_add_index(mr);
-
rxe_add_ref(pd);
err = rxe_mr_init_fast(pd, max_num_sg, mr);
@@ -979,7 +968,6 @@ static struct ib_mr *rxe_alloc_mr(struct
err2:
rxe_drop_ref(pd);
- rxe_drop_index(mr);
rxe_drop_ref(mr);
err1:
return ERR_PTR(err);