pe_event_sample.c

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/*
 * Copyright (c) 2023 NVIDIA CORPORATION AND AFFILIATES.  All rights reserved.
 *
 * 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 the NVIDIA CORPORATION nor the names of its contributors may be used
 *       to endorse or promote products derived from this software without specific prior written
 *       permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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 */
 
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/epoll.h>
#include <sys/eventfd.h>
#include <unistd.h>
 
#include <doca_mmap.h>
#include <doca_buf.h>
#include <doca_buf_inventory.h>
#include <doca_ctx.h>
#include <doca_dma.h>
#include <doca_types.h>
#include <doca_log.h>
#include <doca_pe.h>
 
#include <samples/common.h>
#include "pe_common.h"
 
DOCA_LOG_REGISTER(PE_EVENT::SAMPLE);
 
#define EXIT_ON_FAILURE(_expression_) \
    { \
        doca_error_t _status_ = _expression_; \
\
        if (_status_ != DOCA_SUCCESS) { \
            DOCA_LOG_ERR("%s failed with status %s", __func__, doca_error_get_descr(_status_)); \
            return _status_; \
        } \
    }
 
#define NUM_TASKS (16)
#define DMA_BUFFER_SIZE (1024)
#define BUFFER_SIZE (DMA_BUFFER_SIZE * 2 * NUM_TASKS)
#define BUF_INVENTORY_SIZE (NUM_TASKS * 2)
 
struct pe_event_sample_state {
    struct pe_sample_state_base base;
 
    struct doca_dma *dma;
    struct doca_ctx *dma_ctx;
    struct doca_dma_task_memcpy *tasks[NUM_TASKS];
    int epoll_fd;
};
 
/*
 * DMA Memcpy task completed callback
 *
 * @dma_task [in]: Completed task
 * @task_user_data [in]: doca_data from the task
 * @ctx_user_data [in]: doca_data from the context
 */
static void dma_memcpy_completed_callback(struct doca_dma_task_memcpy *dma_task,
                      union doca_data task_user_data,
                      union doca_data ctx_user_data)
{
    uint8_t expected_value = (uint8_t)task_user_data.u64;
    struct pe_event_sample_state *state = (struct pe_event_sample_state *)ctx_user_data.ptr;
 
    state->base.num_completed_tasks++;
 
    (void)process_completed_dma_memcpy_task(dma_task, expected_value);
 
    /* The task is no longer required, therefore it can be freed */
    (void)dma_task_free(dma_task);
}
 
/*
 * Memcpy task error callback
 *
 * @dma_task [in]: failed task
 * @task_user_data [in]: doca_data from the task
 * @ctx_user_data [in]: doca_data from the context
 */
static void dma_memcpy_error_callback(struct doca_dma_task_memcpy *dma_task,
                      union doca_data task_user_data,
                      union doca_data ctx_user_data)
{
    struct pe_event_sample_state *state = (struct pe_event_sample_state *)ctx_user_data.ptr;
    struct doca_task *task = doca_dma_task_memcpy_as_task(dma_task);
 
    (void)task_user_data;
 
    /* This sample defines that a task is completed even if it is completed with error */
    state->base.num_completed_tasks++;
 
    DOCA_LOG_ERR("Task failed with status %s", doca_error_get_descr(doca_task_get_status(task)));
 
    /* The task is no longer required, therefore it can be freed */
    (void)dma_task_free(dma_task);
}
 
doca_error_t register_pe_event(struct pe_event_sample_state *state)
{
    doca_event_handle_t event_handle = doca_event_invalid_handle;
    struct epoll_event events_in = {.events = EPOLLIN, .data.fd = 0};
 
    DOCA_LOG_INFO("Registering PE event");
 
    /* This section prepares an epoll that the sample can wait on to be notified that a task is completed */
    state->epoll_fd = epoll_create1(0);
    if (state->epoll_fd == -1) {
        DOCA_LOG_ERR("Failed to create epoll_fd, error=%d", errno);
        return DOCA_ERROR_OPERATING_SYSTEM;
    }
 
    /* doca_event_handle_t is a file descriptor that can be added to an epoll */
    EXIT_ON_FAILURE(doca_pe_get_notification_handle(state->base.pe, &event_handle));
 
    if (epoll_ctl(state->epoll_fd, EPOLL_CTL_ADD, event_handle, &events_in) != 0) {
        DOCA_LOG_ERR("Failed to register epoll, error=%d", errno);
        return DOCA_ERROR_OPERATING_SYSTEM;
    }
 
    return DOCA_SUCCESS;
}
 
doca_error_t create_dma(struct pe_event_sample_state *state)
{
    union doca_data ctx_user_data = {0};
 
    DOCA_LOG_INFO("Creating DMA");
 
    EXIT_ON_FAILURE(doca_dma_create(state->base.device, &state->dma));
    state->dma_ctx = doca_dma_as_ctx(state->dma);
 
    /* A context can only be connected to one PE (PE can run multiple contexts) */
    EXIT_ON_FAILURE(doca_pe_connect_ctx(state->base.pe, state->dma_ctx));
 
    ctx_user_data.ptr = state;
    EXIT_ON_FAILURE(doca_ctx_set_user_data(state->dma_ctx, ctx_user_data));
 
    EXIT_ON_FAILURE(doca_dma_task_memcpy_set_conf(state->dma,
                              dma_memcpy_completed_callback,
                              dma_memcpy_error_callback,
                              NUM_TASKS));
 
    return DOCA_SUCCESS;
}
 
doca_error_t run_for_completion(struct pe_event_sample_state *state)
{
    static const int no_timeout = -1;
    struct epoll_event ep_event = {0};
    int epoll_status = 0;
 
    DOCA_LOG_INFO("Running until all tasks are complete");
 
    do {
        while (doca_pe_progress(state->base.pe) != 0) {
            if (state->base.num_completed_tasks == NUM_TASKS) {
                DOCA_LOG_INFO("All tasks completed");
                return DOCA_SUCCESS;
            }
        }
 
        EXIT_ON_FAILURE(doca_pe_request_notification(state->base.pe));
 
        epoll_status = epoll_wait(state->epoll_fd, &ep_event, 1, no_timeout);
        if (epoll_status == -1) {
            DOCA_LOG_ERR("Failed waiting for event, error=%d", errno);
            return DOCA_ERROR_OPERATING_SYSTEM;
        }
 
        /* handle parameter is not used in Linux */
        EXIT_ON_FAILURE(doca_pe_clear_notification(state->base.pe, 0));
    } while (1);
}
 
void cleanup(struct pe_event_sample_state *state)
{
    /* A context must be stopped before it is destroyed */
    if (state->dma_ctx != NULL)
        (void)doca_ctx_stop(state->dma_ctx);
 
    /* All contexts must be destroyed before PE is destroyed. Context destroy disconnects it from the PE */
    if (state->dma != NULL)
        (void)doca_dma_destroy(state->dma);
 
    pe_sample_base_cleanup(&state->base);
}
 
doca_error_t run(struct pe_event_sample_state *state)
{
    memset(state, 0, sizeof(*state));
 
    state->base.buffer_size = BUFFER_SIZE;
    state->base.buf_inventory_size = BUF_INVENTORY_SIZE;
 
    EXIT_ON_FAILURE(allocate_buffer(&state->base));
    EXIT_ON_FAILURE(open_device(&state->base));
    EXIT_ON_FAILURE(create_mmap(&state->base));
    EXIT_ON_FAILURE(create_buf_inventory(&state->base));
    EXIT_ON_FAILURE(create_pe(&state->base));
    EXIT_ON_FAILURE(register_pe_event(state));
    EXIT_ON_FAILURE(create_dma(state));
    EXIT_ON_FAILURE(doca_ctx_start(state->dma_ctx));
    EXIT_ON_FAILURE(allocate_dma_tasks(&state->base, state->dma, NUM_TASKS, DMA_BUFFER_SIZE, state->tasks));
    EXIT_ON_FAILURE(submit_dma_tasks(NUM_TASKS, state->tasks));
    EXIT_ON_FAILURE(run_for_completion(state));
 
    return DOCA_SUCCESS;
}
 
doca_error_t run_pe_event_sample(void)
{
    struct pe_event_sample_state state;
    doca_error_t status = run(&state);
 
    cleanup(&state);
 
    return status;
}