// 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);
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