From: Bob Pearson <rpearsonhpe@gmail.com>
Date: Sun, 12 Jun 2022 17:34:35 -0500
Subject: RDMA/rxe: Convert read side locking to rcu
Patch-mainline: v6.0-rc1
Git-commit: b54c2a25ace5aed21c9944b7605b623abd2ca99c
References: jsc#PED-1111
Use rcu_read_lock() for protecting read side operations in rxe_pool.c.
Link: https://lore.kernel.org/r/20220612223434.31462-3-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_pool.c | 24 ++++++++----------------
1 file changed, 8 insertions(+), 16 deletions(-)
--- a/drivers/infiniband/sw/rxe/rxe_pool.c
+++ b/drivers/infiniband/sw/rxe/rxe_pool.c
@@ -197,16 +197,15 @@ void *rxe_pool_get_index(struct rxe_pool
{
struct rxe_pool_elem *elem;
struct xarray *xa = &pool->xa;
- unsigned long flags;
void *obj;
- xa_lock_irqsave(xa, flags);
+ rcu_read_lock();
elem = xa_load(xa, index);
if (elem && kref_get_unless_zero(&elem->ref_cnt))
obj = elem->obj;
else
obj = NULL;
- xa_unlock_irqrestore(xa, flags);
+ rcu_read_unlock();
return obj;
}
@@ -223,7 +222,6 @@ int __rxe_cleanup(struct rxe_pool_elem *
struct rxe_pool *pool = elem->pool;
struct xarray *xa = &pool->xa;
static int timeout = RXE_POOL_TIMEOUT;
- unsigned long flags;
int ret, err = 0;
void *xa_ret;
@@ -233,9 +231,7 @@ int __rxe_cleanup(struct rxe_pool_elem *
/* erase xarray entry to prevent looking up
* the pool elem from its index
*/
- xa_lock_irqsave(xa, flags);
- xa_ret = __xa_erase(xa, elem->index);
- xa_unlock_irqrestore(xa, flags);
+ xa_ret = xa_erase(xa, elem->index);
WARN_ON(xa_err(xa_ret));
/* if this is the last call to rxe_put complete the
@@ -280,7 +276,7 @@ int __rxe_cleanup(struct rxe_pool_elem *
pool->cleanup(elem);
if (pool->type == RXE_TYPE_MR)
- kfree(elem->obj);
+ kfree_rcu(elem->obj);
atomic_dec(&pool->num_elem);
@@ -299,12 +295,8 @@ int __rxe_put(struct rxe_pool_elem *elem
void __rxe_finalize(struct rxe_pool_elem *elem)
{
- struct xarray *xa = &elem->pool->xa;
- unsigned long flags;
- void *ret;
-
- xa_lock_irqsave(xa, flags);
- ret = __xa_store(&elem->pool->xa, elem->index, elem, GFP_KERNEL);
- xa_unlock_irqrestore(xa, flags);
- WARN_ON(xa_err(ret));
+ void *xa_ret;
+
+ xa_ret = xa_store(&elem->pool->xa, elem->index, elem, GFP_KERNEL);
+ WARN_ON(xa_err(xa_ret));
}