diff options
Diffstat (limited to 'drivers/infiniband/hw/amso1100/c2_vq.c')
| -rw-r--r-- | drivers/infiniband/hw/amso1100/c2_vq.c | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/amso1100/c2_vq.c b/drivers/infiniband/hw/amso1100/c2_vq.c new file mode 100644 index 000000000000..40caeb5f41b4 --- /dev/null +++ b/drivers/infiniband/hw/amso1100/c2_vq.c @@ -0,0 +1,260 @@ +/* + * Copyright (c) 2005 Ammasso, Inc. All rights reserved. + * Copyright (c) 2005 Open Grid Computing, Inc. 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/slab.h> +#include <linux/spinlock.h> + +#include "c2_vq.h" +#include "c2_provider.h" + +/* + * Verbs Request Objects: + * + * VQ Request Objects are allocated by the kernel verbs handlers. + * They contain a wait object, a refcnt, an atomic bool indicating that the + * adapter has replied, and a copy of the verb reply work request. + * A pointer to the VQ Request Object is passed down in the context + * field of the work request message, and reflected back by the adapter + * in the verbs reply message. The function handle_vq() in the interrupt + * path will use this pointer to: + * 1) append a copy of the verbs reply message + * 2) mark that the reply is ready + * 3) wake up the kernel verbs handler blocked awaiting the reply. + * + * + * The kernel verbs handlers do a "get" to put a 2nd reference on the + * VQ Request object. If the kernel verbs handler exits before the adapter + * can respond, this extra reference will keep the VQ Request object around + * until the adapter's reply can be processed. The reason we need this is + * because a pointer to this object is stuffed into the context field of + * the verbs work request message, and reflected back in the reply message. + * It is used in the interrupt handler (handle_vq()) to wake up the appropriate + * kernel verb handler that is blocked awaiting the verb reply. + * So handle_vq() will do a "put" on the object when it's done accessing it. + * NOTE: If we guarantee that the kernel verb handler will never bail before + * getting the reply, then we don't need these refcnts. + * + * + * VQ Request objects are freed by the kernel verbs handlers only + * after the verb has been processed, or when the adapter fails and + * does not reply. + * + * + * Verbs Reply Buffers: + * + * VQ Reply bufs are local host memory copies of a + * outstanding Verb Request reply + * message. The are always allocated by the kernel verbs handlers, and _may_ be + * freed by either the kernel verbs handler -or- the interrupt handler. The + * kernel verbs handler _must_ free the repbuf, then free the vq request object + * in that order. + */ + +int vq_init(struct c2_dev *c2dev) +{ + sprintf(c2dev->vq_cache_name, "c2-vq:dev%c", + (char) ('0' + c2dev->devnum)); + c2dev->host_msg_cache = + kmem_cache_create(c2dev->vq_cache_name, c2dev->rep_vq.msg_size, 0, + SLAB_HWCACHE_ALIGN, NULL, NULL); + if (c2dev->host_msg_cache == NULL) { + return -ENOMEM; + } + return 0; +} + +void vq_term(struct c2_dev *c2dev) +{ + kmem_cache_destroy(c2dev->host_msg_cache); +} + +/* vq_req_alloc - allocate a VQ Request Object and initialize it. + * The refcnt is set to 1. + */ +struct c2_vq_req *vq_req_alloc(struct c2_dev *c2dev) +{ + struct c2_vq_req *r; + + r = kmalloc(sizeof(struct c2_vq_req), GFP_KERNEL); + if (r) { + init_waitqueue_head(&r->wait_object); + r->reply_msg = (u64) NULL; + r->event = 0; + r->cm_id = NULL; + r->qp = NULL; + atomic_set(&r->refcnt, 1); + atomic_set(&r->reply_ready, 0); + } + return r; +} + + +/* vq_req_free - free the VQ Request Object. It is assumed the verbs handler + * has already free the VQ Reply Buffer if it existed. + */ +void vq_req_free(struct c2_dev *c2dev, struct c2_vq_req *r) +{ + r->reply_msg = (u64) NULL; + if (atomic_dec_and_test(&r->refcnt)) { + kfree(r); + } +} + +/* vq_req_get - reference a VQ Request Object. Done + * only in the kernel verbs handlers. + */ +void vq_req_get(struct c2_dev *c2dev, struct c2_vq_req *r) +{ + atomic_inc(&r->refcnt); +} + + +/* vq_req_put - dereference and potentially free a VQ Request Object. + * + * This is only called by handle_vq() on the + * interrupt when it is done processing + * a verb reply message. If the associated + * kernel verbs handler has already bailed, + * then this put will actually free the VQ + * Request object _and_ the VQ Reply Buffer + * if it exists. + */ +void vq_req_put(struct c2_dev *c2dev, struct c2_vq_req *r) +{ + if (atomic_dec_and_test(&r->refcnt)) { + if (r->reply_msg != (u64) NULL) + vq_repbuf_free(c2dev, + (void *) (unsigned long) r->reply_msg); + kfree(r); + } +} + + +/* + * vq_repbuf_alloc - allocate a VQ Reply Buffer. + */ +void *vq_repbuf_alloc(struct c2_dev *c2dev) +{ + return kmem_cache_alloc(c2dev->host_msg_cache, SLAB_ATOMIC); +} + +/* + * vq_send_wr - post a verbs request message to the Verbs Request Queue. + * If a message is not available in the MQ, then block until one is available. + * NOTE: handle_mq() on the interrupt context will wake up threads blocked here. + * When the adapter drains the Verbs Request Queue, + * it inserts MQ index 0 in to the + * adapter->host activity fifo and interrupts the host. + */ +int vq_send_wr(struct c2_dev *c2dev, union c2wr *wr) +{ + void *msg; + wait_queue_t __wait; + + /* + * grab adapter vq lock + */ + spin_lock(&c2dev->vqlock); + + /* + * allocate msg + */ + msg = c2_mq_alloc(&c2dev->req_vq); + + /* + * If we cannot get a msg, then we'll wait + * When a messages are available, the int handler will wake_up() + * any waiters. + */ + while (msg == NULL) { + pr_debug("%s:%d no available msg in VQ, waiting...\n", + __FUNCTION__, __LINE__); + init_waitqueue_entry(&__wait, current); + add_wait_queue(&c2dev->req_vq_wo, &__wait); + spin_unlock(&c2dev->vqlock); + for (;;) { + set_current_state(TASK_INTERRUPTIBLE); + if (!c2_mq_full(&c2dev->req_vq)) { + break; + } + if (!signal_pending(current)) { + schedule_timeout(1 * HZ); /* 1 second... */ + continue; + } + set_current_state(TASK_RUNNING); + remove_wait_queue(&c2dev->req_vq_wo, &__wait); + return -EINTR; + } + set_current_state(TASK_RUNNING); + remove_wait_queue(&c2dev->req_vq_wo, &__wait); + spin_lock(&c2dev->vqlock); + msg = c2_mq_alloc(&c2dev->req_vq); + } + + /* + * copy wr into adapter msg + */ + memcpy(msg, wr, c2dev->req_vq.msg_size); + + /* + * post msg + */ + c2_mq_produce(&c2dev->req_vq); + + /* + * release adapter vq lock + */ + spin_unlock(&c2dev->vqlock); + return 0; +} + + +/* + * vq_wait_for_reply - block until the adapter posts a Verb Reply Message. + */ +int vq_wait_for_reply(struct c2_dev *c2dev, struct c2_vq_req *req) +{ + if (!wait_event_timeout(req->wait_object, + atomic_read(&req->reply_ready), + 60*HZ)) + return -ETIMEDOUT; + + return 0; +} + +/* + * vq_repbuf_free - Free a Verbs Reply Buffer. + */ +void vq_repbuf_free(struct c2_dev *c2dev, void *reply) +{ + kmem_cache_free(c2dev->host_msg_cache, reply); +} |