/* Copyright 2009 - 2016 Freescale Semiconductor, Inc.
*
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* notice, this list of conditions and the following disclaimer.
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* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Freescale Semiconductor nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* ALTERNATIVELY, this software may be distributed under the terms of the
* GNU General Public License ("GPL") as published by the Free Software
* Foundation, either version 2 of that License or (at your option) any
* later version.
*
* THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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*/
#include "qman_test.h"
#include <linux/dma-mapping.h>
#include <linux/delay.h>
/*
* Algorithm:
*
* Each cpu will have HP_PER_CPU "handlers" set up, each of which incorporates
* an rx/tx pair of FQ objects (both of which are stashed on dequeue). The
* organisation of FQIDs is such that the HP_PER_CPU*NUM_CPUS handlers will
* shuttle a "hot potato" frame around them such that every forwarding action
* moves it from one cpu to another. (The use of more than one handler per cpu
* is to allow enough handlers/FQs to truly test the significance of caching -
* ie. when cache-expiries are occurring.)
*
* The "hot potato" frame content will be HP_NUM_WORDS*4 bytes in size, and the
* first and last words of the frame data will undergo a transformation step on
* each forwarding action. To achieve this, each handler will be assigned a
* 32-bit "mixer", that is produced using a 32-bit LFSR. When a frame is
* received by a handler, the mixer of the expected sender is XOR'd into all
* words of the entire frame, which is then validated against the original
* values. Then, before forwarding, the entire frame is XOR'd with the mixer of
* the current handler. Apart from validating that the frame is taking the
* expected path, this also provides some quasi-realistic overheads to each
* forwarding action - dereferencing *all* the frame data, computation, and
* conditional branching. There is a "special" handler designated to act as the
* instigator of the test by creating an enqueuing the "hot potato" frame, and
* to determine when the test has completed by counting HP_LOOPS iterations.
*
* Init phases:
*
* 1. prepare each cpu's 'hp_cpu' struct using on_each_cpu(,,1) and link them
* into 'hp_cpu_list'. Specifically, set processor_id, allocate HP_PER_CPU
* handlers and link-list them (but do no other handler setup).
*
* 2. scan over 'hp_cpu_list' HP_PER_CPU times, the first time sets each
* hp_cpu's 'iterator' to point to its first handler. With each loop,
* allocate rx/tx FQIDs and mixer values to the hp_cpu's iterator handler
* and advance the iterator for the next loop. This includes a final fixup,
* which connects the last handler to the first (and which is why phase 2
* and 3 are separate).
*
* 3. scan over 'hp_cpu_list' HP_PER_CPU times, the first time sets each
* hp_cpu's 'iterator' to point to its first handler. With each loop,
* initialise FQ objects and advance the iterator for the next loop.
* Moreover, do this initialisation on the cpu it applies to so that Rx FQ
* initialisation targets the correct cpu.
*/
/*
* helper to run something on all cpus (can't use on_each_cpu(), as that invokes
* the fn from irq context, which is too restrictive).
*/
struct bstrap {
int (*fn)(void);
atomic_t started;
};
static int bstrap_fn(void *bs)
{
struct bstrap *bstrap = bs;
int err;
atomic_inc(&bstrap->started);
err = bstrap->fn();
if (err)
return err;
while (!kthread_should_stop())
msleep(20);
return 0;
}
static int on_all_cpus(int (*fn)(void))
{
int cpu;
for_each_cpu(cpu, cpu_online_mask) {
struct bstrap bstrap = {
.fn = fn,
.started = ATOMIC_INIT(0)
};
struct task_struct *k = kthread_create(bstrap_fn, &bstrap,
"hotpotato%d", cpu);
int ret;
if (IS_ERR(k))
return -ENOMEM;
kthread_bind(k, cpu);
wake_up_process(k);
/*
* If we call kthread_stop() before the "wake up" has had an
* effect, then the thread may exit with -EINTR without ever
* running the function. So poll until it's started before
* requesting it to stop.
*/
while (!atomic_read(&bstrap.started))
msleep(20);
ret = kthread_stop(k);
if (ret)
return ret;
}
return 0;
}
struct hp_handler {
/* The following data is stashed when 'rx' is dequeued; */
/* -------------- */
/* The Rx FQ, dequeues of which will stash the entire hp_handler */
struct qman_fq rx;
/* The Tx FQ we should forward to */
struct qman_fq tx;
/* The value we XOR post-dequeue, prior to validating */
u32 rx_mixer;
/* The value we XOR pre-enqueue, after validating */
u32 tx_mixer;
/* what the hotpotato address should be on dequeue */
dma_addr_t addr;
u32 *frame_ptr;
/* The following data isn't (necessarily) stashed on dequeue; */
/* -------------- */
u32 fqid_rx, fqid_tx;
/* list node for linking us into 'hp_cpu' */
struct list_head node;
/* Just to check ... */
unsigned int processor_id;
} ____cacheline_aligned;
struct hp_cpu {
/* identify the cpu we run on; */
unsigned int processor_id;
/* root node for the per-cpu list of handlers */
struct list_head handlers;
/* list node for linking us into 'hp_cpu_list' */
struct list_head node;
/*
* when repeatedly scanning 'hp_list', each time linking the n'th
* handlers together, this is used as per-cpu iterator state
*/
struct hp_handler *iterator;
};
/* Each cpu has one of these */
static DEFINE_PER_CPU(struct hp_cpu, hp_cpus);
/* links together the hp_cpu structs, in first-come first-serve order. */
static LIST_HEAD(hp_cpu_list);
static DEFINE_SPINLOCK(hp_lock);
static unsigned int hp_cpu_list_length;
/* the "special" handler, that starts and terminates the test. */
static struct hp_handler *special_handler;
static int loop_counter;
/* handlers are allocated out of this, so they're properly aligned. */
static struct kmem_cache *hp_handler_slab;
/* this is the frame data */
static void *__frame_ptr;
static u32 *frame_ptr;
static dma_addr_t frame_dma;
/* needed for dma_map*() */
static const struct qm_portal_config *pcfg;
/* the main function waits on this */
static DECLARE_WAIT_QUEUE_HEAD(queue);
#define HP_PER_CPU 2
#define HP_LOOPS 8
/* 80 bytes, like a small ethernet frame, and bleeds into a second cacheline */
#define HP_NUM_WORDS 80
/* First word of the LFSR-based frame data */
#define HP_FIRST_WORD 0xabbaf00d
static inline u32 do_lfsr(u32 prev)
{
return (prev >> 1) ^ (-(prev & 1u) & 0xd0000001u);
}
static int allocate_frame_data(void)
{
u32 lfsr = HP_FIRST_WORD;
int loop;
if (!qman_dma_portal) {
pr_crit("portal not available\n");
return -EIO;
}
pcfg = qman_get_qm_portal_config(qman_dma_portal);
__frame_ptr = kmalloc(4 * HP_NUM_WORDS, GFP_KERNEL);
if (!__frame_ptr)
return -ENOMEM;
frame_ptr = PTR_ALIGN(__frame_ptr, 64);
for (loop = 0; loop < HP_NUM_WORDS; loop++) {
frame_ptr[loop] = lfsr;
lfsr = do_lfsr(lfsr);
}
frame_dma = dma_map_single(pcfg->dev, frame_ptr, 4 * HP_NUM_WORDS,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(pcfg->dev, frame_dma)) {
pr_crit("dma mapping failure\n");
kfree(__frame_ptr);
return -EIO;
}
return 0;
}
static void deallocate_frame_data(void)
{
dma_unmap_single(pcfg->dev, frame_dma, 4 * HP_NUM_WORDS,
DMA_BIDIRECTIONAL);
kfree(__frame_ptr);
}
static inline int process_frame_data(struct hp_handler *handler,
const struct qm_fd *fd)
{
u32 *p = handler->frame_ptr;
u32 lfsr = HP_FIRST_WORD;
int loop;
if (qm_fd_addr_get64(fd) != handler->addr) {
pr_crit("bad frame address, [%llX != %llX]\n",
qm_fd_addr_get64(fd), handler->addr);
return -EIO;
}
for (loop = 0; loop < HP_NUM_WORDS; loop++, p++) {
*p ^= handler->rx_mixer;
if (*p != lfsr) {
pr_crit("corrupt frame data");
return -EIO;
}
*p ^= handler->tx_mixer;
lfsr = do_lfsr(lfsr);
}
return 0;
}
static enum qman_cb_dqrr_result normal_dqrr(struct qman_portal *portal,
struct qman_fq *fq,
const struct qm_dqrr_entry *dqrr,
bool sched_napi)
{
struct hp_handler *handler = (struct hp_handler *)fq;
if (process_frame_data(handler, &dqrr->fd)) {
WARN_ON(1);
goto skip;
}
if (qman_enqueue(&handler->tx, &dqrr->fd)) {
pr_crit("qman_enqueue() failed");
WARN_ON(1);
}
skip:
return qman_cb_dqrr_consume;
}
static enum qman_cb_dqrr_result special_dqrr(struct qman_portal *portal,
struct qman_fq *fq,
const struct qm_dqrr_entry *dqrr,
bool sched_napi)
{
struct hp_handler *handler = (struct hp_handler *)fq;
process_frame_data(handler, &dqrr->fd);
if (++loop_counter < HP_LOOPS) {
if (qman_enqueue(&handler->tx, &dqrr->fd)) {
pr_crit("qman_enqueue() failed");
WARN_ON(1);
goto skip;
}
} else {
pr_info("Received final (%dth) frame\n", loop_counter);
wake_up(&queue);
}
skip:
return qman_cb_dqrr_consume;
}
static int create_per_cpu_handlers(void)
{
struct hp_handler *handler;
int loop;
struct hp_cpu *hp_cpu = this_cpu_ptr(&hp_cpus);
hp_cpu->processor_id = smp_processor_id();
spin_lock(&hp_lock);
list_add_tail(&hp_cpu->node, &hp_cpu_list);
hp_cpu_list_length++;
spin_unlock(&hp_lock);
INIT_LIST_HEAD(&hp_cpu->handlers);
for (loop = 0; loop < HP_PER_CPU; loop++) {
handler = kmem_cache_alloc(hp_handler_slab, GFP_KERNEL);
if (!handler) {
pr_crit("kmem_cache_alloc() failed");
WARN_ON(1);
return -EIO;
}
handler->processor_id = hp_cpu->processor_id;
handler->addr = frame_dma;
handler->frame_ptr = frame_ptr;
list_add_tail(&handler->node, &hp_cpu->handlers);
}
return 0;
}
static int destroy_per_cpu_handlers(void)
{
struct list_head *loop, *tmp;
struct hp_cpu *hp_cpu = this_cpu_ptr(&hp_cpus);
spin_lock(&hp_lock);
list_del(&hp_cpu->node);
spin_unlock(&hp_lock);
list_for_each_safe(loop, tmp, &hp_cpu->handlers) {
u32 flags = 0;
struct hp_handler *handler = list_entry(loop, struct hp_handler,
node);
if (qman_retire_fq(&handler->rx, &flags) ||
(flags & QMAN_FQ_STATE_BLOCKOOS)) {
pr_crit("qman_retire_fq(rx) failed, flags: %x", flags);
WARN_ON(1);
return -EIO;
}
if (qman_oos_fq(&handler->rx)) {
pr_crit("qman_oos_fq(rx) failed");
WARN_ON(1);
return -EIO;
}
qman_destroy_fq(&handler->rx);
qman_destroy_fq(&handler->tx);
qman_release_fqid(handler->fqid_rx);
list_del(&handler->node);
kmem_cache_free(hp_handler_slab, handler);
}
return 0;
}
static inline u8 num_cachelines(u32 offset)
{
u8 res = (offset + (L1_CACHE_BYTES - 1))
/ (L1_CACHE_BYTES);
if (res > 3)
return 3;
return res;
}
#define STASH_DATA_CL \
num_cachelines(HP_NUM_WORDS * 4)
#define STASH_CTX_CL \
num_cachelines(offsetof(struct hp_handler, fqid_rx))
static int init_handler(void *h)
{
struct qm_mcc_initfq opts;
struct hp_handler *handler = h;
int err;
if (handler->processor_id != smp_processor_id()) {
err = -EIO;
goto failed;
}
/* Set up rx */
memset(&handler->rx, 0, sizeof(handler->rx));
if (handler == special_handler)
handler->rx.cb.dqrr = special_dqrr;
else
handler->rx.cb.dqrr = normal_dqrr;
err = qman_create_fq(handler->fqid_rx, 0, &handler->rx);
if (err) {
pr_crit("qman_create_fq(rx) failed");
goto failed;
}
memset(&opts, 0, sizeof(opts));
opts.we_mask = cpu_to_be16(QM_INITFQ_WE_FQCTRL |
QM_INITFQ_WE_CONTEXTA);
opts.fqd.fq_ctrl = cpu_to_be16(QM_FQCTRL_CTXASTASHING);
qm_fqd_set_stashing(&opts.fqd, 0, STASH_DATA_CL, STASH_CTX_CL);
err = qman_init_fq(&handler->rx, QMAN_INITFQ_FLAG_SCHED |
QMAN_INITFQ_FLAG_LOCAL, &opts);
if (err) {
pr_crit("qman_init_fq(rx) failed");
goto failed;
}
/* Set up tx */
memset(&handler->tx, 0, sizeof(handler->tx));
err = qman_create_fq(handler->fqid_tx, QMAN_FQ_FLAG_NO_MODIFY,
&handler->tx);
if (err) {
pr_crit("qman_create_fq(tx) failed");
goto failed;
}
return 0;
failed:
return err;
}
static void init_handler_cb(void *h)
{
if (init_handler(h))
WARN_ON(1);
}
static int init_phase2(void)
{
int loop;
u32 fqid = 0;
u32 lfsr = 0xdeadbeef;
struct hp_cpu *hp_cpu;
struct hp_handler *handler;
for (loop = 0; loop < HP_PER_CPU; loop++) {
list_for_each_entry(hp_cpu, &hp_cpu_list, node) {
int err;
if (!loop)
hp_cpu->iterator = list_first_entry(
&hp_cpu->handlers,
struct hp_handler, node);
else
hp_cpu->iterator = list_entry(
hp_cpu->iterator->node.next,
struct hp_handler, node);
/* Rx FQID is the previous handler's Tx FQID */
hp_cpu->iterator->fqid_rx = fqid;
/* Allocate new FQID for Tx */
err = qman_alloc_fqid(&fqid);
if (err) {
pr_crit("qman_alloc_fqid() failed");
return err;
}
hp_cpu->iterator->fqid_tx = fqid;
/* Rx mixer is the previous handler's Tx mixer */
hp_cpu->iterator->rx_mixer = lfsr;
/* Get new mixer for Tx */
lfsr = do_lfsr(lfsr);
hp_cpu->iterator->tx_mixer = lfsr;
}
}
/* Fix up the first handler (fqid_rx==0, rx_mixer=0xdeadbeef) */
hp_cpu = list_first_entry(&hp_cpu_list, struct hp_cpu, node);
handler = list_first_entry(&hp_cpu->handlers, struct hp_handler, node);
if (handler->fqid_rx != 0 || handler->rx_mixer != 0xdeadbeef)
return 1;
handler->fqid_rx = fqid;
handler->rx_mixer = lfsr;
/* and tag it as our "special" handler */
special_handler = handler;
return 0;
}
static int init_phase3(void)
{
int loop, err;
struct hp_cpu *hp_cpu;
for (loop = 0; loop < HP_PER_CPU; loop++) {
list_for_each_entry(hp_cpu, &hp_cpu_list, node) {
if (!loop)
hp_cpu->iterator = list_first_entry(
&hp_cpu->handlers,
struct hp_handler, node);
else
hp_cpu->iterator = list_entry(
hp_cpu->iterator->node.next,
struct hp_handler, node);
preempt_disable();
if (hp_cpu->processor_id == smp_processor_id()) {
err = init_handler(hp_cpu->iterator);
if (err)
return err;
} else {
smp_call_function_single(hp_cpu->processor_id,
init_handler_cb, hp_cpu->iterator, 1);
}
preempt_enable();
}
}
return 0;
}
static int send_first_frame(void *ignore)
{
u32 *p = special_handler->frame_ptr;
u32 lfsr = HP_FIRST_WORD;
int loop, err;
struct qm_fd fd;
if (special_handler->processor_id != smp_processor_id()) {
err = -EIO;
goto failed;
}
memset(&fd, 0, sizeof(fd));
qm_fd_addr_set64(&fd, special_handler->addr);
qm_fd_set_contig_big(&fd, HP_NUM_WORDS * 4);
for (loop = 0; loop < HP_NUM_WORDS; loop++, p++) {
if (*p != lfsr) {
err = -EIO;
pr_crit("corrupt frame data");
goto failed;
}
*p ^= special_handler->tx_mixer;
lfsr = do_lfsr(lfsr);
}
pr_info("Sending first frame\n");
err = qman_enqueue(&special_handler->tx, &fd);
if (err) {
pr_crit("qman_enqueue() failed");
goto failed;
}
return 0;
failed:
return err;
}
static void send_first_frame_cb(void *ignore)
{
if (send_first_frame(NULL))
WARN_ON(1);
}
int qman_test_stash(void)
{
int err;
if (cpumask_weight(cpu_online_mask) < 2) {
pr_info("%s(): skip - only 1 CPU\n", __func__);
return 0;
}
pr_info("%s(): Starting\n", __func__);
hp_cpu_list_length = 0;
loop_counter = 0;
hp_handler_slab = kmem_cache_create("hp_handler_slab",
sizeof(struct hp_handler), L1_CACHE_BYTES,
SLAB_HWCACHE_ALIGN, NULL);
if (!hp_handler_slab) {
err = -EIO;
pr_crit("kmem_cache_create() failed");
goto failed;
}
err = allocate_frame_data();
if (err)
goto failed;
/* Init phase 1 */
pr_info("Creating %d handlers per cpu...\n", HP_PER_CPU);
if (on_all_cpus(create_per_cpu_handlers)) {
err = -EIO;
pr_crit("on_each_cpu() failed");
goto failed;
}
pr_info("Number of cpus: %d, total of %d handlers\n",
hp_cpu_list_length, hp_cpu_list_length * HP_PER_CPU);
err = init_phase2();
if (err)
goto failed;
err = init_phase3();
if (err)
goto failed;
preempt_disable();
if (special_handler->processor_id == smp_processor_id()) {
err = send_first_frame(NULL);
if (err)
goto failed;
} else {
smp_call_function_single(special_handler->processor_id,
send_first_frame_cb, NULL, 1);
}
preempt_enable();
wait_event(queue, loop_counter == HP_LOOPS);
deallocate_frame_data();
if (on_all_cpus(destroy_per_cpu_handlers)) {
err = -EIO;
pr_crit("on_each_cpu() failed");
goto failed;
}
kmem_cache_destroy(hp_handler_slab);
pr_info("%s(): Finished\n", __func__);
return 0;
failed:
WARN_ON(1);
return err;
}
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