// SPDX-License-Identifier: GPL-2.0-or-later
/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright 2002-2007 H. Peter Anvin - All Rights Reserved
 *
 * ----------------------------------------------------------------------- */

/*
 * raid6test.c
 *
 * Test RAID-6 recovery with various algorithms
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <linux/raid/pq.h>

#define NDISKS          16      /* Including P and Q */

const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));

char *dataptrs[NDISKS];
char data[NDISKS][PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
char recovi[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));
char recovj[PAGE_SIZE] __attribute__((aligned(PAGE_SIZE)));

static void makedata(int start, int stop)
{
        int i, j;

        for (i = start; i <= stop; i++) {
                for (j = 0; j < PAGE_SIZE; j++)
                        data[i][j] = rand();

                dataptrs[i] = data[i];
        }
}

static char disk_type(int d)
{
        switch (d) {
        case NDISKS-2:
                return 'P';
        case NDISKS-1:
                return 'Q';
        default:
                return 'D';
        }
}

static int test_disks(int i, int j)
{
        int erra, errb;

        memset(recovi, 0xf0, PAGE_SIZE);
        memset(recovj, 0xba, PAGE_SIZE);

        dataptrs[i] = recovi;
        dataptrs[j] = recovj;

        raid6_dual_recov(NDISKS, PAGE_SIZE, i, j, (void **)&dataptrs);

        erra = memcmp(data[i], recovi, PAGE_SIZE);
        errb = memcmp(data[j], recovj, PAGE_SIZE);

        if (i < NDISKS-2 && j == NDISKS-1) {
                /* We don't implement the DQ failure scenario, since it's
                   equivalent to a RAID-5 failure (XOR, then recompute Q) */
                erra = errb = 0;
        } else {
                printf("algo=%-8s  faila=%3d(%c)  failb=%3d(%c)  %s\n",
                       raid6_call.name,
                       i, disk_type(i),
                       j, disk_type(j),
                       (!erra && !errb) ? "OK" :
                       !erra ? "ERRB" :
                       !errb ? "ERRA" : "ERRAB");
        }

        dataptrs[i] = data[i];
        dataptrs[j] = data[j];

        return erra || errb;
}

int main(int argc, char *argv[])
{
        const struct raid6_calls *const *algo;
        const struct raid6_recov_calls *const *ra;
        int i, j, p1, p2;
        int err = 0;

        makedata(0, NDISKS-1);

        for (ra = raid6_recov_algos; *ra; ra++) {
                if ((*ra)->valid  && !(*ra)->valid())
                        continue;

                raid6_2data_recov = (*ra)->data2;
                raid6_datap_recov = (*ra)->datap;

                printf("using recovery %s\n", (*ra)->name);

                for (algo = raid6_algos; *algo; algo++) {
                        if ((*algo)->valid && !(*algo)->valid())
                                continue;

                        raid6_call = **algo;

                        /* Nuke syndromes */
                        memset(data[NDISKS-2], 0xee, 2*PAGE_SIZE);

                        /* Generate assumed good syndrome */
                        raid6_call.gen_syndrome(NDISKS, PAGE_SIZE,
                                                (void **)&dataptrs);

                        for (i = 0; i < NDISKS-1; i++)
                                for (j = i+1; j < NDISKS; j++)
                                        err += test_disks(i, j);

                        if (!raid6_call.xor_syndrome)
                                continue;

                        for (p1 = 0; p1 < NDISKS-2; p1++)
                                for (p2 = p1; p2 < NDISKS-2; p2++) {

                                        /* Simulate rmw run */
                                        raid6_call.xor_syndrome(NDISKS, p1, p2, PAGE_SIZE,
                                                                (void **)&dataptrs);
                                        makedata(p1, p2);
                                        raid6_call.xor_syndrome(NDISKS, p1, p2, PAGE_SIZE,
                                                                (void **)&dataptrs);

                                        for (i = 0; i < NDISKS-1; i++)
                                                for (j = i+1; j < NDISKS; j++)
                                                        err += test_disks(i, j);
                                }

                }
                printf("\n");
        }

        printf("\n");
        /* Pick the best algorithm test */
        raid6_select_algo();

        if (err)
                printf("\n*** ERRORS FOUND ***\n");

        return err;
}