1 files changed, 507 insertions, 0 deletions

diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
new file mode 100644
index 000000000..a70876a0a
--- /dev/null
+++ b/drivers/infiniband/core/cq.c
@@ -0,0 +1,507 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015 HGST, a Western Digital Company.
+ */
+#include <linux/err.h>
+#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
+#define IB_POLL_BATCH_DIRECT		8
+
+/* # of WCs to iterate over before yielding */
+#define IB_POLL_BUDGET_IRQ		256
+#define IB_POLL_BUDGET_WORKQUEUE	65536
+
+#define IB_POLL_FLAGS \
+	(IB_CQ_NEXT_COMP | IB_CQ_REPORT_MISSED_EVENTS)
+
+static const struct dim_cq_moder
+rdma_dim_prof[RDMA_DIM_PARAMS_NUM_PROFILES] = {
+	{1,   0, 1,  0},
+	{1,   0, 4,  0},
+	{2,   0, 4,  0},
+	{2,   0, 8,  0},
+	{4,   0, 8,  0},
+	{16,  0, 8,  0},
+	{16,  0, 16, 0},
+	{32,  0, 16, 0},
+	{32,  0, 32, 0},
+};
+
+static void ib_cq_rdma_dim_work(struct work_struct *w)
+{
+	struct dim *dim = container_of(w, struct dim, work);
+	struct ib_cq *cq = dim->priv;
+
+	u16 usec = rdma_dim_prof[dim->profile_ix].usec;
+	u16 comps = rdma_dim_prof[dim->profile_ix].comps;
+
+	dim->state = DIM_START_MEASURE;
+
+	trace_cq_modify(cq, comps, usec);
+	cq->device->ops.modify_cq(cq, comps, usec);
+}
+
+static void rdma_dim_init(struct ib_cq *cq)
+{
+	struct dim *dim;
+
+	if (!cq->device->ops.modify_cq || !cq->device->use_cq_dim ||
+	    cq->poll_ctx == IB_POLL_DIRECT)
+		return;
+
+	dim = kzalloc(sizeof(struct dim), GFP_KERNEL);
+	if (!dim)
+		return;
+
+	dim->state = DIM_START_MEASURE;
+	dim->tune_state = DIM_GOING_RIGHT;
+	dim->profile_ix = RDMA_DIM_START_PROFILE;
+	dim->priv = cq;
+	cq->dim = dim;
+
+	INIT_WORK(&dim->work, ib_cq_rdma_dim_work);
+}
+
+static void rdma_dim_destroy(struct ib_cq *cq)
+{
+	if (!cq->dim)
+		return;
+
+	cancel_work_sync(&cq->dim->work);
+	kfree(cq->dim);
+}
+
+static int __poll_cq(struct ib_cq *cq, int num_entries, struct ib_wc *wc)
+{
+	int rc;
+
+	rc = ib_poll_cq(cq, num_entries, wc);
+	trace_cq_poll(cq, num_entries, rc);
+	return rc;
+}
+
+static int __ib_process_cq(struct ib_cq *cq, int budget, struct ib_wc *wcs,
+			   int batch)
+{
+	int i, n, completed = 0;
+
+	trace_cq_process(cq);
+
+	/*
+	 * budget might be (-1) if the caller does not
+	 * want to bound this call, thus we need unsigned
+	 * minimum here.
+	 */
+	while ((n = __poll_cq(cq, min_t(u32, batch,
+					budget - completed), wcs)) > 0) {
+		for (i = 0; i < n; i++) {
+			struct ib_wc *wc = &wcs[i];
+
+			if (wc->wr_cqe)
+				wc->wr_cqe->done(cq, wc);
+			else
+				WARN_ON_ONCE(wc->status == IB_WC_SUCCESS);
+		}
+
+		completed += n;
+
+		if (n != batch || (budget != -1 && completed >= budget))
+			break;
+	}
+
+	return completed;
+}
+
+/**
+ * ib_process_cq_direct - process a CQ in caller context
+ * @cq:		CQ to process
+ * @budget:	number of CQEs to poll for
+ *
+ * This function is used to process all outstanding CQ entries.
+ * It does not offload CQ processing to a different context and does
+ * not ask for completion interrupts from the HCA.
+ * Using direct processing on CQ with non IB_POLL_DIRECT type may trigger
+ * concurrent processing.
+ *
+ * Note: do not pass -1 as %budget unless it is guaranteed that the number
+ * of completions that will be processed is small.
+ */
+int ib_process_cq_direct(struct ib_cq *cq, int budget)
+{
+	struct ib_wc wcs[IB_POLL_BATCH_DIRECT];
+
+	return __ib_process_cq(cq, budget, wcs, IB_POLL_BATCH_DIRECT);
+}
+EXPORT_SYMBOL(ib_process_cq_direct);
+
+static void ib_cq_completion_direct(struct ib_cq *cq, void *private)
+{
+	WARN_ONCE(1, "got unsolicited completion for CQ 0x%p\n", cq);
+}
+
+static int ib_poll_handler(struct irq_poll *iop, int budget)
+{
+	struct ib_cq *cq = container_of(iop, struct ib_cq, iop);
+	struct dim *dim = cq->dim;
+	int completed;
+
+	completed = __ib_process_cq(cq, budget, cq->wc, IB_POLL_BATCH);
+	if (completed < budget) {
+		irq_poll_complete(&cq->iop);
+		if (ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0) {
+			trace_cq_reschedule(cq);
+			irq_poll_sched(&cq->iop);
+		}
+	}
+
+	if (dim)
+		rdma_dim(dim, completed);
+
+	return completed;
+}
+
+static void ib_cq_completion_softirq(struct ib_cq *cq, void *private)
+{
+	trace_cq_schedule(cq);
+	irq_poll_sched(&cq->iop);
+}
+
+static void ib_cq_poll_work(struct work_struct *work)
+{
+	struct ib_cq *cq = container_of(work, struct ib_cq, work);
+	int completed;
+
+	completed = __ib_process_cq(cq, IB_POLL_BUDGET_WORKQUEUE, cq->wc,
+				    IB_POLL_BATCH);
+	if (completed >= IB_POLL_BUDGET_WORKQUEUE ||
+	    ib_req_notify_cq(cq, IB_POLL_FLAGS) > 0)
+		queue_work(cq->comp_wq, &cq->work);
+	else if (cq->dim)
+		rdma_dim(cq->dim, completed);
+}
+
+static void ib_cq_completion_workqueue(struct ib_cq *cq, void *private)
+{
+	trace_cq_schedule(cq);
+	queue_work(cq->comp_wq, &cq->work);
+}
+
+/**
+ * __ib_alloc_cq - allocate a completion queue
+ * @dev:		device to allocate the CQ for
+ * @private:		driver private data, accessible from cq->cq_context
+ * @nr_cqe:		number of CQEs to allocate
+ * @comp_vector:	HCA completion vectors for this CQ
+ * @poll_ctx:		context to poll the CQ from.
+ * @caller:		module owner name.
+ *
+ * This is the proper interface to allocate a CQ for in-kernel users. A
+ * CQ allocated with this interface will automatically be polled from the
+ * specified context. The ULP must use wr->wr_cqe instead of wr->wr_id
+ * to use this CQ abstraction.
+ */
+struct ib_cq *__ib_alloc_cq(struct ib_device *dev, void *private, int nr_cqe,
+			    int comp_vector, enum ib_poll_context poll_ctx,
+			    const char *caller)
+{
+	struct ib_cq_init_attr cq_attr = {
+		.cqe		= nr_cqe,
+		.comp_vector	= comp_vector,
+	};
+	struct ib_cq *cq;
+	int ret = -ENOMEM;
+
+	cq = rdma_zalloc_drv_obj(dev, ib_cq);
+	if (!cq)
+		return ERR_PTR(ret);
+
+	cq->device = dev;
+	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)
+		goto out_free_cq;
+
+	rdma_restrack_new(&cq->res, RDMA_RESTRACK_CQ);
+	rdma_restrack_set_name(&cq->res, caller);
+
+	ret = dev->ops.create_cq(cq, &cq_attr, NULL);
+	if (ret)
+		goto out_free_wc;
+
+	rdma_dim_init(cq);
+
+	switch (cq->poll_ctx) {
+	case IB_POLL_DIRECT:
+		cq->comp_handler = ib_cq_completion_direct;
+		break;
+	case IB_POLL_SOFTIRQ:
+		cq->comp_handler = ib_cq_completion_softirq;
+
+		irq_poll_init(&cq->iop, IB_POLL_BUDGET_IRQ, ib_poll_handler);
+		ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
+		break;
+	case IB_POLL_WORKQUEUE:
+	case IB_POLL_UNBOUND_WORKQUEUE:
+		cq->comp_handler = ib_cq_completion_workqueue;
+		INIT_WORK(&cq->work, ib_cq_poll_work);
+		ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
+		cq->comp_wq = (cq->poll_ctx == IB_POLL_WORKQUEUE) ?
+				ib_comp_wq : ib_comp_unbound_wq;
+		break;
+	default:
+		ret = -EINVAL;
+		goto out_destroy_cq;
+	}
+
+	rdma_restrack_add(&cq->res);
+	trace_cq_alloc(cq, nr_cqe, comp_vector, poll_ctx);
+	return cq;
+
+out_destroy_cq:
+	rdma_dim_destroy(cq);
+	cq->device->ops.destroy_cq(cq, NULL);
+out_free_wc:
+	rdma_restrack_put(&cq->res);
+	kfree(cq->wc);
+out_free_cq:
+	kfree(cq);
+	trace_cq_alloc_error(nr_cqe, comp_vector, poll_ctx, ret);
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL(__ib_alloc_cq);
+
+/**
+ * __ib_alloc_cq_any - allocate a completion queue
+ * @dev:		device to allocate the CQ for
+ * @private:		driver private data, accessible from cq->cq_context
+ * @nr_cqe:		number of CQEs to allocate
+ * @poll_ctx:		context to poll the CQ from
+ * @caller:		module owner name
+ *
+ * Attempt to spread ULP Completion Queues over each device's interrupt
+ * vectors. A simple best-effort mechanism is used.
+ */
+struct ib_cq *__ib_alloc_cq_any(struct ib_device *dev, void *private,
+				int nr_cqe, enum ib_poll_context poll_ctx,
+				const char *caller)
+{
+	static atomic_t counter;
+	int comp_vector = 0;
+
+	if (dev->num_comp_vectors > 1)
+		comp_vector =
+			atomic_inc_return(&counter) %
+			min_t(int, dev->num_comp_vectors, num_online_cpus());
+
+	return __ib_alloc_cq(dev, private, nr_cqe, comp_vector, poll_ctx,
+			     caller);
+}
+EXPORT_SYMBOL(__ib_alloc_cq_any);
+
+/**
+ * ib_free_cq - free a completion queue
+ * @cq:		completion queue to free.
+ */
+void ib_free_cq(struct ib_cq *cq)
+{
+	int ret;
+
+	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:
+		break;
+	case IB_POLL_SOFTIRQ:
+		irq_poll_disable(&cq->iop);
+		break;
+	case IB_POLL_WORKQUEUE:
+	case IB_POLL_UNBOUND_WORKQUEUE:
+		cancel_work_sync(&cq->work);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+	}
+
+	rdma_dim_destroy(cq);
+	trace_cq_free(cq);
+	ret = cq->device->ops.destroy_cq(cq, NULL);
+	WARN_ONCE(ret, "Destroy of kernel CQ shouldn't fail");
+	rdma_restrack_del(&cq->res);
+	kfree(cq->wc);
+	kfree(cq);
+}
+EXPORT_SYMBOL(ib_free_cq);
+
+void ib_cq_pool_cleanup(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);
+			list_del(&cq->pool_entry);
+			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, *n;
+	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_safe(cq, n, &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);