x15/test/test_pmap_update_mp.c

/*
 * Copyright (c) 2014 Richard Braun.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *
 * The purpose of this test module is to check that the pmap module properly
 * synchronizes page tables across processors. Two threads are created and
 * bound to processors 0 and 1 respectively. The first thread allocates a
 * page and writes it, making sure physical mappings are up-to-date locally.
 * It then transfers the page address to the second thread which validates
 * the content of the page, an operation that can only be done if the page
 * tables of the current processor have been updated.
 */

#include <stddef.h>
#include <stdio.h>
#include <string.h>

#include <kern/condition.h>
#include <kern/cpumap.h>
#include <kern/error.h>
#include <kern/init.h>
#include <kern/mutex.h>
#include <kern/panic.h>
#include <kern/thread.h>
#include <machine/page.h>
#include <test/test.h>
#include <vm/vm_kmem.h>

static struct condition test_condition;
static struct mutex test_lock;
static void *test_va;

static void
test_run1(void *arg)
{
    void *ptr;

    (void)arg;

    printf("allocating page\n");
    ptr = vm_kmem_alloc(PAGE_SIZE);
    printf("writing page\n");
    memset(ptr, 'a', PAGE_SIZE);

    printf("passing page to second thread (%p)\n", ptr);

    mutex_lock(&test_lock);
    test_va = ptr;
    condition_signal(&test_condition);
    mutex_unlock(&test_lock);
}

static void
test_run2(void *arg)
{
    char *ptr;
    unsigned int i;

    (void)arg;

    printf("waiting for page\n");

    mutex_lock(&test_lock);

    while (test_va == NULL) {
        condition_wait(&test_condition, &test_lock);
    }

    ptr = test_va;

    mutex_unlock(&test_lock);

    printf("page received (%p), checking page\n", ptr);

    for (i = 0; i < PAGE_SIZE; i++) {
        if (ptr[i] != 'a') {
            panic("invalid content");
        }
    }

    vm_kmem_free(ptr, PAGE_SIZE);
    printf("done\n");
}

void __init
test_setup(void)
{
    struct thread_attr attr;
    struct thread *thread;
    struct cpumap *cpumap;
    int error;

    condition_init(&test_condition);
    mutex_init(&test_lock);
    test_va = NULL;

    error = cpumap_create(&cpumap);
    error_check(error, "cpumap_create");

    cpumap_zero(cpumap);
    cpumap_set(cpumap, 0);
    thread_attr_init(&attr, THREAD_KERNEL_PREFIX "test_run1");
    thread_attr_set_detached(&attr);
    thread_attr_set_cpumap(&attr, cpumap);
    error = thread_create(&thread, &attr, test_run1, NULL);
    error_check(error, "thread_create");

    cpumap_zero(cpumap);
    cpumap_set(cpumap, 1);
    thread_attr_init(&attr, THREAD_KERNEL_PREFIX "test_run2");
    thread_attr_set_detached(&attr);
    thread_attr_set_cpumap(&attr, cpumap);
    error = thread_create(&thread, &attr, test_run2, NULL);
    error_check(error, "thread_create");

    cpumap_destroy(cpumap);
}