#include <linux/err.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/kthread.h>
#include "qib_verbs.h"
#include "qib.h"
/**
* qib_cq_enter - add a new entry to the completion queue
* @cq: completion queue
* @entry: work completion entry to add
* @sig: true if @entry is a solicitated entry
*
* This may be called with qp->s_lock held.
*/
void qib_cq_enter(struct qib_cq *cq, struct ib_wc *entry, int solicited)
{
struct qib_cq_wc *wc;
unsigned long flags;
u32 head;
u32 next;
spin_lock_irqsave(&cq->lock, flags);
/*
* Note that the head pointer might be writable by user processes.
* Take care to verify it is a sane value.
*/
wc = cq->queue;
head = wc->head;
if (head >= (unsigned) cq->ibcq.cqe) {
head = cq->ibcq.cqe;
next = 0;
} else
next = head + 1;
if (unlikely(next == wc->tail)) {
spin_unlock_irqrestore(&cq->lock, flags);
if (cq->ibcq.event_handler) {
struct ib_event ev;
ev.device = cq->ibcq.device;
ev.element.cq = &cq->ibcq;
ev.event = IB_EVENT_CQ_ERR;
cq->ibcq.event_handler(&ev, cq->ibcq.cq_context);
}
return;
}
if (cq->ip) {
wc->uqueue[head].wr_id = entry->wr_id;
wc->uqueue[head].status = entry->status;
wc->uqueue[head].opcode = entry->opcode;
wc->uqueue[head].vendor_err = entry->vendor_err;
wc->uqueue[head].byte_len = entry->byte_len;
wc->uqueue[head].ex.imm_data =
(__u32 __force)entry->ex.imm_data;
wc->uqueue[head].qp_num = entry->qp->qp_num;
wc->uqueue[head].src_qp = entry->src_qp;
wc->uqueue[head].wc_flags = entry->wc_flags;
wc->uqueue[head].pkey_index = entry->pkey_index;
wc->uqueue[head].slid = entry->slid;
wc->uqueue[head].sl = entry->sl;
wc->uqueue[head].dlid_path_bits = entry->dlid_path_bits;
wc->uqueue[head].port_num = entry->port_num;
/* Make sure entry is written before the head index. */
smp_wmb();
} else
wc->kqueue[head] = *entry;
wc->head = next;
if (cq->notify == IB_CQ_NEXT_COMP ||
(cq->notify == IB_CQ_SOLICITED &&
(solicited || entry->status != IB_WC_SUCCESS))) {
struct kthread_worker *worker;
/*
* This will cause send_complete() to be called in
* another thread.
*/
smp_rmb();
worker = cq->dd->worker;
if (likely(worker)) {
cq->notify = IB_CQ_NONE;
cq->triggered++;
queue_kthread_work(worker, &cq->comptask);
}
}
spin_unlock_irqrestore(&cq->lock, flags);
}
/**
* qib_poll_cq - poll for work completion entries
* @ibcq: the completion queue to poll
* @num_entries: the maximum number of entries to return
* @entry: pointer to array where work completions are placed
*
* Returns the number of completion entries polled.
*
* This may be called from interrupt context. Also called by ib_poll_cq()
* in the generic verbs code.
*/
int qib_poll_cq(struct ib_cq *ibcq, int num_entries, struct ib_wc *entry)
{
struct qib_cq *cq = to_icq(ibcq);
struct qib_cq_wc *wc;
unsigned long flags;
int npolled;
u32 tail;
/* The kernel can only poll a kernel completion queue */
if (cq->ip) {
npolled = -EINVAL;
goto bail;
}
spin_lock_irqsave(&cq->lock, flags);
wc = cq->queue;
tail = wc->tail;
if (tail > (u32) cq->ibcq.cqe)
tail = (u32) cq->ibcq.cqe;
for (npolled = 0; npolled < num_entries; ++npolled, ++entry) {
if (tail == wc->head)
break;
/* The kernel doesn't need a RMB since it has the lock. */
*entry = wc->kqueue[tail];
if (tail >= cq->ibcq.cqe)
tail = 0;
else
tail++;
}
wc->tail = tail;
spin_unlock_irqrestore(&cq->lock, flags);
bail:
return npolled;
}
static void send_complete(struct kthread_work *work)
{
struct qib_cq *cq = container_of(work, struct qib_cq, comptask);
/*
* The completion handler will most likely rearm the notification
* and poll for all pending entries. If a new completion entry
* is added while we are in this routine, queue_work()
* won't call us again until we return so we check triggered to
* see if we need to call the handler again.
*/
for (;;) {
u8 triggered = cq->triggered;
/*
* IPoIB connected mode assumes the callback is from a
* soft IRQ. We simulate this by blocking "bottom halves".
* See the implementation for ipoib_cm_handle_tx_wc(),
* netif_tx_lock_bh() and netif_tx_lock().
*/
local_bh_disable();
cq->ibcq.comp_handler(&cq->ibcq, cq->ibcq.cq_context);
local_bh_enable();
if (cq->triggered == triggered)
return;
}
}
/**
* qib_create_cq - create a completion queue
* @ibdev: the device this completion queue is attached to
* @entries: the minimum size of the completion queue
* @context: unused by the QLogic_IB driver
* @udata: user data for libibverbs.so
*
* Returns a pointer to the completion queue or negative errno values
* for failure.
*
* Called by ib_create_cq() in the generic verbs code.
*/
struct ib_cq *qib_create_cq(struct ib_device *ibdev, int entries,
int comp_vector, struct ib_ucontext *context,
struct ib_udata *udata)
{
struct qib_ibdev *dev = to_idev(ibdev);
struct qib_cq *cq;
struct qib_cq_wc *wc;
struct ib_cq *ret;
u32 sz;
if (entries < 1 || entries > ib_qib_max_cqes) {
ret = ERR_PTR(-EINVAL);
goto done;
}
/* Allocate the completion queue structure. */
cq = kmalloc(sizeof(*cq), GFP_KERNEL);
if (!cq) {
ret = ERR_PTR(-ENOMEM);
goto done;
}
/*
* Allocate the completion queue entries and head/tail pointers.
* This is allocated separately so that it can be resized and
* also mapped into user space.
* We need to use vmalloc() in order to support mmap and large
* numbers of entries.
*/
sz = sizeof(*wc);
if (udata && udata->outlen >= sizeof(__u64))
sz += sizeof(struct ib_uverbs_wc) * (entries + 1);
else
sz += sizeof(struct ib_wc) * (entries + 1);
wc = vmalloc_user(sz);
if (!wc) {
ret = ERR_PTR(-ENOMEM);
goto bail_cq;
}
/*
* Return the address of the WC as the offset to mmap.
* See qib_mmap() for details.
*/
if (udata && udata->outlen >= sizeof(__u64)) {
int err;
cq->ip = qib_create_mmap_info(dev, sz, context, wc);
if (!cq->ip) {
ret = ERR_PTR(-ENOMEM);
goto bail_wc;
}
err = ib_copy_to_udata(udata, &cq->ip->offset,
sizeof(cq->ip->offset));
if (err) {
ret = ERR_PTR(err);
goto bail_ip;
}
} else
cq->ip = NULL;
spin_lock(&dev->n_cqs_lock);
if (dev->n_cqs_allocated == ib_qib_max_cqs) {
spin_unlock(&dev->n_cqs_lock);
ret = ERR_PTR(-ENOMEM);
goto bail_ip;
}
dev->n_cqs_allocated++;
spin_unlock(&dev->n_cqs_lock);
if (cq->ip) {
spin_lock_irq(&dev->pending_lock);
list_add(&cq->ip->pending_mmaps, &dev->pending_mmaps);
spin_unlock_irq(&dev->pending_lock);
}
/*
* ib_create_cq() will initialize cq->ibcq except for cq->ibcq.cqe.
* The number of entries should be >= the number requested or return
* an error.
*/
cq->dd = dd_from_dev(dev);
cq->ibcq.cqe = entries;
cq->notify = IB_CQ_NONE;
cq->triggered = 0;
spin_lock_init(&cq->lock);
init_kthread_work(&cq->comptask, send_complete);
wc->head = 0;
wc->tail = 0;
cq->queue = wc;
ret = &cq->ibcq;
goto done;
bail_ip:
kfree(cq->ip);
bail_wc:
vfree(wc);
bail_cq:
kfree(cq);
done:
return ret;
}
/**
* qib_destroy_cq - destroy a completion queue
* @ibcq: the completion queue to destroy.
*
* Returns 0 for success.
*
* Called by ib_destroy_cq() in the generic verbs code.
*/
int qib_destroy_cq(struct ib_cq *ibcq)
{
struct qib_ibdev *dev = to_idev(ibcq->device);
struct qib_cq *cq = to_icq(ibcq);
flush_kthread_work(&cq->comptask);
spin_lock(&dev->n_cqs_lock);
dev->n_cqs_allocated--;
spin_unlock(&dev->n_cqs_lock);
if (cq->ip)
kref_put(&cq->ip->ref, qib_release_mmap_info);
else
vfree(cq->queue);
kfree(cq);
return 0;
}
/**
* qib_req_notify_cq - change the notification type for a completion queue
* @ibcq: the completion queue
* @notify_flags: the type of notification to request
*
* Returns 0 for success.
*
* This may be called from interrupt context. Also called by
* ib_req_notify_cq() in the generic verbs code.
*/
int qib_req_notify_cq(struct ib_
