// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2020, Oracle and/or its affiliates.
 *    Author: Alan Maguire <alan.maguire@oracle.com>
 */

#include <linux/debugfs.h>
#include <linux/module.h>

#include <kunit/test.h>
#include <kunit/test-bug.h>

#include "string-stream.h"
#include "debugfs.h"

#define KUNIT_DEBUGFS_ROOT             "kunit"
#define KUNIT_DEBUGFS_RESULTS          "results"
#define KUNIT_DEBUGFS_RUN              "run"

/*
 * Create a debugfs representation of test suites:
 *
 * Path                                         Semantics
 * /sys/kernel/debug/kunit/<testsuite>/results  Show results of last run for
 *                                              testsuite
 * /sys/kernel/debug/kunit/<testsuite>/run      Write to this file to trigger
 *                                              testsuite to run
 *
 */

static struct dentry *debugfs_rootdir;

void kunit_debugfs_cleanup(void)
{
        debugfs_remove_recursive(debugfs_rootdir);
}

void kunit_debugfs_init(void)
{
        if (!debugfs_rootdir)
                debugfs_rootdir = debugfs_create_dir(KUNIT_DEBUGFS_ROOT, NULL);
}

static void debugfs_print_result(struct seq_file *seq, struct string_stream *log)
{
        struct string_stream_fragment *frag_container;

        if (!log)
                return;

        /*
         * Walk the fragments so we don't need to allocate a temporary
         * buffer to hold the entire string.
         */
        spin_lock(&log->lock);
        list_for_each_entry(frag_container, &log->fragments, node)
                seq_printf(seq, "%s", frag_container->fragment);
        spin_unlock(&log->lock);
}

/*
 * /sys/kernel/debug/kunit/<testsuite>/results shows all results for testsuite.
 */
static int debugfs_print_results(struct seq_file *seq, void *v)
{
        struct kunit_suite *suite = (struct kunit_suite *)seq->private;
        enum kunit_status success;
        struct kunit_case *test_case;

        if (!suite)
                return 0;

        success = kunit_suite_has_succeeded(suite);

        /* Print KTAP header so the debugfs log can be parsed as valid KTAP. */
        seq_puts(seq, "KTAP version 1\n");
        seq_puts(seq, "1..1\n");

        /* Print suite header because it is not stored in the test logs. */
        seq_puts(seq, KUNIT_SUBTEST_INDENT "KTAP version 1\n");
        seq_printf(seq, KUNIT_SUBTEST_INDENT "# Subtest: %s\n", suite->name);
        seq_printf(seq, KUNIT_SUBTEST_INDENT "1..%zd\n", kunit_suite_num_test_cases(suite));

        kunit_suite_for_each_test_case(suite, test_case)
                debugfs_print_result(seq, test_case->log);

        debugfs_print_result(seq, suite->log);

        seq_printf(seq, "%s %d %s\n",
                   kunit_status_to_ok_not_ok(success), 1, suite->name);
        return 0;
}

static int debugfs_release(struct inode *inode, struct file *file)
{
        return single_release(inode, file);
}

static int debugfs_results_open(struct inode *inode, struct file *file)
{
        struct kunit_suite *suite;

        suite = (struct kunit_suite *)inode->i_private;

        return single_open(file, debugfs_print_results, suite);
}

/*
 * Print a usage message to the debugfs "run" file
 * (/sys/kernel/debug/kunit/<testsuite>/run) if opened.
 */
static int debugfs_print_run(struct seq_file *seq, void *v)
{
        struct kunit_suite *suite = (struct kunit_suite *)seq->private;

        seq_puts(seq, "Write to this file to trigger the test suite to run.\n");
        seq_printf(seq, "usage: echo \"any string\" > /sys/kernel/debugfs/kunit/%s/run\n",
                        suite->name);
        return 0;
}

/*
 * The debugfs "run" file (/sys/kernel/debug/kunit/<testsuite>/run)
 * contains no information. Write to the file to trigger the test suite
 * to run.
 */
static int debugfs_run_open(struct inode *inode, struct file *file)
{
        struct kunit_suite *suite;

        suite = (struct kunit_suite *)inode->i_private;

        return single_open(file, debugfs_print_run, suite);
}

/*
 * Trigger a test suite to run by writing to the suite's "run" debugfs
 * file found at: /sys/kernel/debug/kunit/<testsuite>/run
 *
 * Note: what is written to this file will not be saved.
 */
static ssize_t debugfs_run(struct file *file,
                const char __user *buf, size_t count, loff_t *ppos)
{
        struct inode *f_inode = file->f_inode;
        struct kunit_suite *suite = (struct kunit_suite *) f_inode->i_private;

        __kunit_test_suites_init(&suite, 1, true);

        return count;
}

static const struct file_operations debugfs_results_fops = {
        .open = debugfs_results_open,
        .read = seq_read,
        .llseek = seq_lseek,
        .release = debugfs_release,
};

static const struct file_operations debugfs_run_fops = {
        .open = debugfs_run_open,
        .read = seq_read,
        .write = debugfs_run,
        .llseek = seq_lseek,
        .release = debugfs_release,
};

void kunit_debugfs_create_suite(struct kunit_suite *suite)
{
        struct kunit_case *test_case;
        struct string_stream *stream;

        /* If suite log already allocated, do not create new debugfs files. */
        if (suite->log)
                return;

        /*
         * Allocate logs before creating debugfs representation.
         * The suite->log and test_case->log pointer are expected to be NULL
         * if there isn't a log, so only set it if the log stream was created
         * successfully.
         */
        stream = alloc_string_stream(GFP_KERNEL);
        if (IS_ERR(stream))
                return;

        string_stream_set_append_newlines(stream, true);
        suite->log = stream;

        kunit_suite_for_each_test_case(suite, test_case) {
                stream = alloc_string_stream(GFP_KERNEL);
                if (IS_ERR(stream))
                        goto err;

                string_stream_set_append_newlines(stream, true);
                test_case->log = stream;
        }

        suite->debugfs = debugfs_create_dir(suite->name, debugfs_rootdir);

        debugfs_create_file(KUNIT_DEBUGFS_RESULTS, S_IFREG | 0444,
                            suite->debugfs,
                            suite, &debugfs_results_fops);

        /* Do not create file to re-run test if test runs on init */
        if (!suite->is_init) {
                debugfs_create_file(KUNIT_DEBUGFS_RUN, S_IFREG | 0644,
                                    suite->debugfs,
                                    suite, &debugfs_run_fops);
        }
        return;

err:
        string_stream_destroy(suite->log);
        suite->log = NULL;
        kunit_suite_for_each_test_case(suite, test_case) {
                string_stream_destroy(test_case->log);
                test_case->log = NULL;
        }
}

void kunit_debugfs_destroy_suite(struct kunit_suite *suite)
{
        struct kunit_case *test_case;

        debugfs_remove_recursive(suite->debugfs);
        string_stream_destroy(suite->log);
        kunit_suite_for_each_test_case(suite, test_case)
                string_stream_destroy(test_case->log);
}