diff options
Diffstat (limited to 'net/rds/iw_ring.c')
| -rw-r--r-- | net/rds/iw_ring.c | 169 |
1 files changed, 0 insertions, 169 deletions
diff --git a/net/rds/iw_ring.c b/net/rds/iw_ring.c deleted file mode 100644 index da8e3b63f663..000000000000 --- a/net/rds/iw_ring.c +++ /dev/null @@ -1,169 +0,0 @@ -/* - * Copyright (c) 2006 Oracle. All rights reserved. - * - * This software is available to you under a choice of one of two - * licenses. You may choose to be licensed under the terms of the GNU - * General Public License (GPL) Version 2, available from the file - * COPYING in the main directory of this source tree, or the - * OpenIB.org BSD license below: - * - * Redistribution and use in source and binary forms, with or - * without modification, are permitted provided that the following - * conditions are met: - * - * - Redistributions of source code must retain the above - * copyright notice, this list of conditions and the following - * disclaimer. - * - * - Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following - * disclaimer in the documentation and/or other materials - * provided with the distribution. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, - * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF - * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND - * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS - * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN - * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN - * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE - * SOFTWARE. - * - */ -#include <linux/kernel.h> - -#include "rds.h" -#include "iw.h" - -/* - * Locking for IB rings. - * We assume that allocation is always protected by a mutex - * in the caller (this is a valid assumption for the current - * implementation). - * - * Freeing always happens in an interrupt, and hence only - * races with allocations, but not with other free()s. - * - * The interaction between allocation and freeing is that - * the alloc code has to determine the number of free entries. - * To this end, we maintain two counters; an allocation counter - * and a free counter. Both are allowed to run freely, and wrap - * around. - * The number of used entries is always (alloc_ctr - free_ctr) % NR. - * - * The current implementation makes free_ctr atomic. When the - * caller finds an allocation fails, it should set an "alloc fail" - * bit and retry the allocation. The "alloc fail" bit essentially tells - * the CQ completion handlers to wake it up after freeing some - * more entries. - */ - -/* - * This only happens on shutdown. - */ -DECLARE_WAIT_QUEUE_HEAD(rds_iw_ring_empty_wait); - -void rds_iw_ring_init(struct rds_iw_work_ring *ring, u32 nr) -{ - memset(ring, 0, sizeof(*ring)); - ring->w_nr = nr; - rdsdebug("ring %p nr %u\n", ring, ring->w_nr); -} - -static inline u32 __rds_iw_ring_used(struct rds_iw_work_ring *ring) -{ - u32 diff; - - /* This assumes that atomic_t has at least as many bits as u32 */ - diff = ring->w_alloc_ctr - (u32) atomic_read(&ring->w_free_ctr); - BUG_ON(diff > ring->w_nr); - - return diff; -} - -void rds_iw_ring_resize(struct rds_iw_work_ring *ring, u32 nr) -{ - /* We only ever get called from the connection setup code, - * prior to creating the QP. */ - BUG_ON(__rds_iw_ring_used(ring)); - ring->w_nr = nr; -} - -static int __rds_iw_ring_empty(struct rds_iw_work_ring *ring) -{ - return __rds_iw_ring_used(ring) == 0; -} - -u32 rds_iw_ring_alloc(struct rds_iw_work_ring *ring, u32 val, u32 *pos) -{ - u32 ret = 0, avail; - - avail = ring->w_nr - __rds_iw_ring_used(ring); - - rdsdebug("ring %p val %u next %u free %u\n", ring, val, - ring->w_alloc_ptr, avail); - - if (val && avail) { - ret = min(val, avail); - *pos = ring->w_alloc_ptr; - - ring->w_alloc_ptr = (ring->w_alloc_ptr + ret) % ring->w_nr; - ring->w_alloc_ctr += ret; - } - - return ret; -} - -void rds_iw_ring_free(struct rds_iw_work_ring *ring, u32 val) -{ - ring->w_free_ptr = (ring->w_free_ptr + val) % ring->w_nr; - atomic_add(val, &ring->w_free_ctr); - - if (__rds_iw_ring_empty(ring) && - waitqueue_active(&rds_iw_ring_empty_wait)) - wake_up(&rds_iw_ring_empty_wait); -} - -void rds_iw_ring_unalloc(struct rds_iw_work_ring *ring, u32 val) -{ - ring->w_alloc_ptr = (ring->w_alloc_ptr - val) % ring->w_nr; - ring->w_alloc_ctr -= val; -} - -int rds_iw_ring_empty(struct rds_iw_work_ring *ring) -{ - return __rds_iw_ring_empty(ring); -} - -int rds_iw_ring_low(struct rds_iw_work_ring *ring) -{ - return __rds_iw_ring_used(ring) <= (ring->w_nr >> 1); -} - - -/* - * returns the oldest alloced ring entry. This will be the next one - * freed. This can't be called if there are none allocated. - */ -u32 rds_iw_ring_oldest(struct rds_iw_work_ring *ring) -{ - return ring->w_free_ptr; -} - -/* - * returns the number of completed work requests. - */ - -u32 rds_iw_ring_completed(struct rds_iw_work_ring *ring, u32 wr_id, u32 oldest) -{ - u32 ret; - - if (oldest <= (unsigned long long)wr_id) - ret = (unsigned long long)wr_id - oldest + 1; - else - ret = ring->w_nr - oldest + (unsigned long long)wr_id + 1; - - rdsdebug("ring %p ret %u wr_id %u oldest %u\n", ring, ret, - wr_id, oldest); - return ret; -} |