#include <linux/slab.h>
#include <rdma/ib_verbs.h>
+#include "core_priv.h"
+
#include <trace/events/rdma_core.h>
+/* Max size for shared CQ, may require tuning */
+#define IB_MAX_SHARED_CQ_SZ 4096U
/* # of WCs to poll for with a single call to ib_poll_cq */
#define IB_POLL_BATCH 16
cq->cq_context = private;
cq->poll_ctx = poll_ctx;
atomic_set(&cq->usecnt, 0);
+ cq->comp_vector = comp_vector;
cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);
if (!cq->wc)
{
if (WARN_ON_ONCE(atomic_read(&cq->usecnt)))
return;
+ if (WARN_ON_ONCE(cq->cqe_used))
+ return;
switch (cq->poll_ctx) {
case IB_POLL_DIRECT:
kfree(cq);
}
EXPORT_SYMBOL(ib_free_cq_user);
+
+void ib_cq_pool_init(struct ib_device *dev)
+{
+ unsigned int i;
+
+ spin_lock_init(&dev->cq_pools_lock);
+ for (i = 0; i < ARRAY_SIZE(dev->cq_pools); i++)
+ INIT_LIST_HEAD(&dev->cq_pools[i]);
+}
+
+void ib_cq_pool_destroy(struct ib_device *dev)
+{
+ struct ib_cq *cq, *n;
+ unsigned int i;
+
+ for (i = 0; i < ARRAY_SIZE(dev->cq_pools); i++) {
+ list_for_each_entry_safe(cq, n, &dev->cq_pools[i],
+ pool_entry) {
+ WARN_ON(cq->cqe_used);
+ cq->shared = false;
+ ib_free_cq(cq);
+ }
+ }
+}
+
+static int ib_alloc_cqs(struct ib_device *dev, unsigned int nr_cqes,
+ enum ib_poll_context poll_ctx)
+{
+ LIST_HEAD(tmp_list);
+ unsigned int nr_cqs, i;
+ struct ib_cq *cq;
+ int ret;
+
+ if (poll_ctx > IB_POLL_LAST_POOL_TYPE) {
+ WARN_ON_ONCE(poll_ctx > IB_POLL_LAST_POOL_TYPE);
+ return -EINVAL;
+ }
+
+ /*
+ * Allocate at least as many CQEs as requested, and otherwise
+ * a reasonable batch size so that we can share CQs between
+ * multiple users instead of allocating a larger number of CQs.
+ */
+ nr_cqes = min_t(unsigned int, dev->attrs.max_cqe,
+ max(nr_cqes, IB_MAX_SHARED_CQ_SZ));
+ nr_cqs = min_t(unsigned int, dev->num_comp_vectors, num_online_cpus());
+ for (i = 0; i < nr_cqs; i++) {
+ cq = ib_alloc_cq(dev, NULL, nr_cqes, i, poll_ctx);
+ if (IS_ERR(cq)) {
+ ret = PTR_ERR(cq);
+ goto out_free_cqs;
+ }
+ cq->shared = true;
+ list_add_tail(&cq->pool_entry, &tmp_list);
+ }
+
+ spin_lock_irq(&dev->cq_pools_lock);
+ list_splice(&tmp_list, &dev->cq_pools[poll_ctx]);
+ spin_unlock_irq(&dev->cq_pools_lock);
+
+ return 0;
+
+out_free_cqs:
+ list_for_each_entry(cq, &tmp_list, pool_entry) {
+ cq->shared = false;
+ ib_free_cq(cq);
+ }
+ return ret;
+}
+
+/**
+ * ib_cq_pool_get() - Find the least used completion queue that matches
+ * a given cpu hint (or least used for wild card affinity) and fits
+ * nr_cqe.
+ * @dev: rdma device
+ * @nr_cqe: number of needed cqe entries
+ * @comp_vector_hint: completion vector hint (-1) for the driver to assign
+ * a comp vector based on internal counter
+ * @poll_ctx: cq polling context
+ *
+ * Finds a cq that satisfies @comp_vector_hint and @nr_cqe requirements and
+ * claim entries in it for us. In case there is no available cq, allocate
+ * a new cq with the requirements and add it to the device pool.
+ * IB_POLL_DIRECT cannot be used for shared cqs so it is not a valid value
+ * for @poll_ctx.
+ */
+struct ib_cq *ib_cq_pool_get(struct ib_device *dev, unsigned int nr_cqe,
+ int comp_vector_hint,
+ enum ib_poll_context poll_ctx)
+{
+ static unsigned int default_comp_vector;
+ unsigned int vector, num_comp_vectors;
+ struct ib_cq *cq, *found = NULL;
+ int ret;
+
+ if (poll_ctx > IB_POLL_LAST_POOL_TYPE) {
+ WARN_ON_ONCE(poll_ctx > IB_POLL_LAST_POOL_TYPE);
+ return ERR_PTR(-EINVAL);
+ }
+
+ num_comp_vectors =
+ min_t(unsigned int, dev->num_comp_vectors, num_online_cpus());
+ /* Project the affinty to the device completion vector range */
+ if (comp_vector_hint < 0) {
+ comp_vector_hint =
+ (READ_ONCE(default_comp_vector) + 1) % num_comp_vectors;
+ WRITE_ONCE(default_comp_vector, comp_vector_hint);
+ }
+ vector = comp_vector_hint % num_comp_vectors;
+
+ /*
+ * Find the least used CQ with correct affinity and
+ * enough free CQ entries
+ */
+ while (!found) {
+ spin_lock_irq(&dev->cq_pools_lock);
+ list_for_each_entry(cq, &dev->cq_pools[poll_ctx],
+ pool_entry) {
+ /*
+ * Check to see if we have found a CQ with the
+ * correct completion vector
+ */
+ if (vector != cq->comp_vector)
+ continue;
+ if (cq->cqe_used + nr_cqe > cq->cqe)
+ continue;
+ found = cq;
+ break;
+ }
+
+ if (found) {
+ found->cqe_used += nr_cqe;
+ spin_unlock_irq(&dev->cq_pools_lock);
+
+ return found;
+ }
+ spin_unlock_irq(&dev->cq_pools_lock);
+
+ /*
+ * Didn't find a match or ran out of CQs in the device
+ * pool, allocate a new array of CQs.
+ */
+ ret = ib_alloc_cqs(dev, nr_cqe, poll_ctx);
+ if (ret)
+ return ERR_PTR(ret);
+ }
+
+ return found;
+}
+EXPORT_SYMBOL(ib_cq_pool_get);
+
+/**
+ * ib_cq_pool_put - Return a CQ taken from a shared pool.
+ * @cq: The CQ to return.
+ * @nr_cqe: The max number of cqes that the user had requested.
+ */
+void ib_cq_pool_put(struct ib_cq *cq, unsigned int nr_cqe)
+{
+ if (WARN_ON_ONCE(nr_cqe > cq->cqe_used))
+ return;
+
+ spin_lock_irq(&cq->device->cq_pools_lock);
+ cq->cqe_used -= nr_cqe;
+ spin_unlock_irq(&cq->device->cq_pools_lock);
+}
+EXPORT_SYMBOL(ib_cq_pool_put);
projects / linux-2.6-microblaze.git / blobdiff