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Release 4.11 drivers/soc/fsl/qbman/qman_test_stash.c

/* Copyright 2009 - 2016 Freescale Semiconductor, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       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;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#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; }

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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; }

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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); }

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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; }

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static void deallocate_frame_data(void) { dma_unmap_single(pcfg->dev, frame_dma, 4 * HP_NUM_WORDS, DMA_BIDIRECTIONAL); kfree(__frame_ptr); }

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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; }

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static enum qman_cb_dqrr_result normal_dqrr(struct qman_portal *portal, struct qman_fq *fq, const struct qm_dqrr_entry *dqrr) { 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; }

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static enum qman_cb_dqrr_result special_dqrr(struct qman_portal *portal, struct qman_fq *fq, const struct qm_dqrr_entry *dqrr) { 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; }

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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; }

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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; }

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static inline u8 num_cachelines(u32 offset) { u8 res = (offset + (L1_CACHE_BYTES - 1)) / (L1_CACHE_BYTES); if (res > 3) return 3; return res; }

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#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; }

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static void init_handler_cb(void *h) { if (init_handler(h)) WARN_ON(1); }

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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; }

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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; }

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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; }

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static void send_first_frame_cb(void *ignore) { if (send_first_frame(NULL)) WARN_ON(1); }

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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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