/*
 * Test the powerpc alignment handler on POWER8/POWER9
 *
 * Copyright (C) 2017 IBM Corporation (Michael Neuling, Andrew Donnellan)
 *
 * 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
 * 2 of the License, or (at your option) any later version.
 */

/*
 * This selftest exercises the powerpc alignment fault handler.
 *
 * We create two sets of source and destination buffers, one in regular memory,
 * the other cache-inhibited (we use /dev/fb0 for this).
 *
 * We initialise the source buffers, then use whichever set of load/store
 * instructions is under test to copy bytes from the source buffers to the
 * destination buffers. For the regular buffers, these instructions will
 * execute normally. For the cache-inhibited buffers, these instructions
 * will trap and cause an alignment fault, and the alignment fault handler
 * will emulate the particular instruction under test. We then compare the
 * destination buffers to ensure that the native and emulated cases give the
 * same result.
 *
 * TODO:
 *   - Any FIXMEs below
 *   - Test VSX regs < 32 and > 32
 *   - Test all loads and stores
 *   - Check update forms do update register
 *   - Test alignment faults over page boundary
 *
 * Some old binutils may not support all the instructions.
 */


#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <getopt.h>
#include <setjmp.h>
#include <signal.h>

#include <asm/cputable.h>

#include "utils.h"

int bufsize;
int debug;
int testing;
volatile int gotsig;

void sighandler(int sig, siginfo_t *info, void *ctx)
{
        ucontext_t *ucp = ctx;

        if (!testing) {
                signal(sig, SIG_DFL);
                kill(0, sig);
        }
        gotsig = sig;
#ifdef __powerpc64__
        ucp->uc_mcontext.gp_regs[PT_NIP] += 4;
#else
        ucp->uc_mcontext.uc_regs->gregs[PT_NIP] += 4;
#endif
}

#define XFORM(reg, n)  " " #reg " ,%"#n",%2 ;"
#define DFORM(reg, n)  " " #reg " ,0(%"#n") ;"

#define TEST(name, ld_op, st_op, form, ld_reg, st_reg)          \
        void test_##name(char *s, char *d)                      \
        {                                                       \
                asm volatile(                                   \
                        #ld_op form(ld_reg, 0)                  \
                        #st_op form(st_reg, 1)                  \
                        :: "r"(s), "r"(d), "r"(0)               \
                        : "memory", "vs0", "vs32", "r31");      \
        }                                                       \
        rc |= do_test(#name, test_##name)

#define LOAD_VSX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 32, 32)
#define STORE_VSX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 32)
#define LOAD_VSX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 32, 32)
#define STORE_VSX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 32)
#define LOAD_VMX_XFORM_TEST(op) TEST(op, op, stxvd2x, XFORM, 0, 32)
#define STORE_VMX_XFORM_TEST(op) TEST(op, lxvd2x, op, XFORM, 32, 0)
#define LOAD_VMX_DFORM_TEST(op) TEST(op, op, stxv, DFORM, 0, 32)
#define STORE_VMX_DFORM_TEST(op) TEST(op, lxv, op, DFORM, 32, 0)

#define LOAD_XFORM_TEST(op) TEST(op, op, stdx, XFORM, 31, 31)
#define STORE_XFORM_TEST(op) TEST(op, ldx, op, XFORM, 31, 31)
#define LOAD_DFORM_TEST(op) TEST(op, op, std, DFORM, 31, 31)
#define STORE_DFORM_TEST(op) TEST(op, ld, op, DFORM, 31, 31)

#define LOAD_FLOAT_DFORM_TEST(op)  TEST(op, op, stfd, DFORM, 0, 0)
#define STORE_FLOAT_DFORM_TEST(op) TEST(op, lfd, op, DFORM, 0, 0)
#define LOAD_FLOAT_XFORM_TEST(op)  TEST(op, op, stfdx, XFORM, 0, 0)
#define STORE_FLOAT_XFORM_TEST(op) TEST(op, lfdx, op, XFORM, 0, 0)


/* FIXME: Unimplemented tests: */
// STORE_DFORM_TEST(stq)   /* FIXME: need two registers for quad */
// STORE_DFORM_TEST(stswi) /* FIXME: string instruction */

// STORE_XFORM_TEST(stwat) /* AMO can't emulate or run on CI */
// STORE_XFORM_TEST(stdat) /* ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ */


/* preload byte by byte */
void preload_data(void *dst, int offset, int width)
{
        char *c = dst;
        int i;

        c += offset;

        for (i = 0 ; i < width ; i++)
                c[i] = i;
}

int test_memcpy(void *dst, void *src, int size, int offset,
                void (*test_func)(char *, char *))
{
        char *s, *d;

        s = src;
        s += offset;
        d = dst;
        d += offset;

        assert(size == 16);
        gotsig = 0;
        testing = 1;

        test_func(s, d); /* run the actual test */

        testing = 0;
        if (gotsig) {
                if (debug)
                        printf("  Got signal %i\n", gotsig);
                return 1;
        }
        return 0;
}

void dumpdata(char *s1, char *s2, int n, char *test_name)
{
        int i;

        printf("  %s: unexpected result:\n", test_name);
        printf("    mem:");
        for (i = 0; i < n; i++)
                printf(" %02x", s1[i]);
        printf("\n");
        printf("    ci: ");
        for (i = 0; i < n; i++)
                printf(" %02x", s2[i]);
        printf("\n");
}

int test_memcmp(void *s1, void *s2, int n, int offset, char *test_name)
{
        char *s1c, *s2c;

        s1c = s1;
        s1c += offset;
        s2c = s2;
        s2c += offset;

        if (memcmp(s1c, s2c, n)) {
                if (debug) {
                        printf("\n  Compare failed. Offset:%i length:%i\n",
                               offset, n);
                        dumpdata(s1c, s2c, n, test_name);
                }
                return 1;
        }
        return 0;
}

/*
 * Do two memcpy tests using the same instructions. One cachable
 * memory and the other doesn't.
 */
int do_test(char *test_name, void (*test_func)(char *, char *))
{
        int offset, width, fd, rc, r;
        void *mem0, *mem1, *ci0, *ci1;

        printf("\tDoing %s:\t", test_name);

        fd = open("/dev/fb0", O_RDWR);
        if (fd < 0) {
                printf("\n");
                perror("Can't open /dev/fb0 now?");
                return 1;
        }

        ci0 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
                   fd, 0x0);
        ci1 = mmap(NULL, bufsize, PROT_WRITE, MAP_SHARED,
                   fd, bufsize);
        if ((ci0 == MAP_FAILED) || (ci1 == MAP_FAILED)) {
                printf("\n");
                perror("mmap failed");
                SKIP_IF(1);
        }

        rc = posix_memalign(&mem0, bufsize, bufsize);
        if (rc) {
                printf("\n");
                return rc;
        }

        rc = posix_memalign(&mem1, bufsize, bufsize);
        if (rc) {
                printf("\n");
                free(mem0);
                return rc;
        }

        rc = 0;
        /*
         * offset = 0 is aligned but tests the workaround for the P9N
         * DD2.1 vector CI load issue (see 5080332c2c89 "powerpc/64s:
         * Add workaround for P9 vector CI load issue")
         */
        for (offset = 0; offset < 16; offset++) {
                width = 16; /* vsx == 16 bytes */
                r = 0;

                /* load pattern into memory byte by byte */
                preload_data(ci0, offset, width);
                preload_data(mem0, offset, width); // FIXME: remove??
                memcpy(ci0, mem0, bufsize);
                memcpy(ci1, mem1, bufsize); /* initialise output to the same */

                /* sanity check */
                test_memcmp(mem0, ci0, width, offset, test_name);

                r |= test_memcpy(ci1,  ci0,  width, offset, test_func);
                r |= test_memcpy(mem1, mem0, width, offset, test_func);
                if (r && !debug) {
                        printf("FAILED: Got signal");
                        rc = 1;
                        break;
                }

                r |= test_memcmp(mem1, ci1, width, offset, test_name);
                if (r && !debug) {
                        printf("FAILED: Wrong Data");
                        rc = 1;
                        break;
                }
        }

        if (rc == 0)
                printf("PASSED");

        printf("\n");

        munmap(ci0, bufsize);
        munmap(ci1, bufsize);
        free(mem0);
        free(mem1);
        close(fd);

        return rc;
}

static bool can_open_fb0(void)
{
        int fd;

        fd = open("/dev/fb0", O_RDWR);
        if (fd < 0)
                return false;

        close(fd);
        return true;
}

int test_alignment_handler_vsx_206(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());
        SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));

        printf("VSX: 2.06B\n");
        LOAD_VSX_XFORM_TEST(lxvd2x);
        LOAD_VSX_XFORM_TEST(lxvw4x);
        LOAD_VSX_XFORM_TEST(lxsdx);
        LOAD_VSX_XFORM_TEST(lxvdsx);
        STORE_VSX_XFORM_TEST(stxvd2x);
        STORE_VSX_XFORM_TEST(stxvw4x);
        STORE_VSX_XFORM_TEST(stxsdx);
        return rc;
}

int test_alignment_handler_vsx_207(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());
        SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));

        printf("VSX: 2.07B\n");
        LOAD_VSX_XFORM_TEST(lxsspx);
        LOAD_VSX_XFORM_TEST(lxsiwax);
        LOAD_VSX_XFORM_TEST(lxsiwzx);
        STORE_VSX_XFORM_TEST(stxsspx);
        STORE_VSX_XFORM_TEST(stxsiwx);
        return rc;
}

int test_alignment_handler_vsx_300(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());

        SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_3_00));
        printf("VSX: 3.00B\n");
        LOAD_VMX_DFORM_TEST(lxsd);
        LOAD_VSX_XFORM_TEST(lxsibzx);
        LOAD_VSX_XFORM_TEST(lxsihzx);
        LOAD_VMX_DFORM_TEST(lxssp);
        LOAD_VSX_DFORM_TEST(lxv);
        LOAD_VSX_XFORM_TEST(lxvb16x);
        LOAD_VSX_XFORM_TEST(lxvh8x);
        LOAD_VSX_XFORM_TEST(lxvx);
        LOAD_VSX_XFORM_TEST(lxvwsx);
        LOAD_VSX_XFORM_TEST(lxvl);
        LOAD_VSX_XFORM_TEST(lxvll);
        STORE_VMX_DFORM_TEST(stxsd);
        STORE_VSX_XFORM_TEST(stxsibx);
        STORE_VSX_XFORM_TEST(stxsihx);
        STORE_VMX_DFORM_TEST(stxssp);
        STORE_VSX_DFORM_TEST(stxv);
        STORE_VSX_XFORM_TEST(stxvb16x);
        STORE_VSX_XFORM_TEST(stxvh8x);
        STORE_VSX_XFORM_TEST(stxvx);
        STORE_VSX_XFORM_TEST(stxvl);
        STORE_VSX_XFORM_TEST(stxvll);
        return rc;
}

int test_alignment_handler_integer(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());

        printf("Integer\n");
        LOAD_DFORM_TEST(lbz);
        LOAD_DFORM_TEST(lbzu);
        LOAD_XFORM_TEST(lbzx);
        LOAD_XFORM_TEST(lbzux);
        LOAD_DFORM_TEST(lhz);
        LOAD_DFORM_TEST(lhzu);
        LOAD_XFORM_TEST(lhzx);
        LOAD_XFORM_TEST(lhzux);
        LOAD_DFORM_TEST(lha);
        LOAD_DFORM_TEST(lhau);
        LOAD_XFORM_TEST(lhax);
        LOAD_XFORM_TEST(lhaux);
        LOAD_XFORM_TEST(lhbrx);
        LOAD_DFORM_TEST(lwz);
        LOAD_DFORM_TEST(lwzu);
        LOAD_XFORM_TEST(lwzx);
        LOAD_XFORM_TEST(lwzux);
        LOAD_DFORM_TEST(lwa);
        LOAD_XFORM_TEST(lwax);
        LOAD_XFORM_TEST(lwaux);
        LOAD_XFORM_TEST(lwbrx);
        LOAD_DFORM_TEST(ld);
        LOAD_DFORM_TEST(ldu);
        LOAD_XFORM_TEST(ldx);
        LOAD_XFORM_TEST(ldux);
        LOAD_DFORM_TEST(lmw);
        STORE_DFORM_TEST(stb);
        STORE_XFORM_TEST(stbx);
        STORE_DFORM_TEST(stbu);
        STORE_XFORM_TEST(stbux);
        STORE_DFORM_TEST(sth);
        STORE_XFORM_TEST(sthx);
        STORE_DFORM_TEST(sthu);
        STORE_XFORM_TEST(sthux);
        STORE_XFORM_TEST(sthbrx);
        STORE_DFORM_TEST(stw);
        STORE_XFORM_TEST(stwx);
        STORE_DFORM_TEST(stwu);
        STORE_XFORM_TEST(stwux);
        STORE_XFORM_TEST(stwbrx);
        STORE_DFORM_TEST(std);
        STORE_XFORM_TEST(stdx);
        STORE_DFORM_TEST(stdu);
        STORE_XFORM_TEST(stdux);
        STORE_DFORM_TEST(stmw);

        return rc;
}

int test_alignment_handler_integer_206(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());
        SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));

        printf("Integer: 2.06\n");

        LOAD_XFORM_TEST(ldbrx);
        STORE_XFORM_TEST(stdbrx);

        return rc;
}

int test_alignment_handler_vmx(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());
        SKIP_IF(!have_hwcap(PPC_FEATURE_HAS_ALTIVEC));

        printf("VMX\n");
        LOAD_VMX_XFORM_TEST(lvx);

        /*
         * FIXME: These loads only load part of the register, so our
         * testing method doesn't work. Also they don't take alignment
         * faults, so it's kinda pointless anyway
         *
         LOAD_VMX_XFORM_TEST(lvebx)
         LOAD_VMX_XFORM_TEST(lvehx)
         LOAD_VMX_XFORM_TEST(lvewx)
         LOAD_VMX_XFORM_TEST(lvxl)
        */
        STORE_VMX_XFORM_TEST(stvx);
        STORE_VMX_XFORM_TEST(stvebx);
        STORE_VMX_XFORM_TEST(stvehx);
        STORE_VMX_XFORM_TEST(stvewx);
        STORE_VMX_XFORM_TEST(stvxl);
        return rc;
}

int test_alignment_handler_fp(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());

        printf("Floating point\n");
        LOAD_FLOAT_DFORM_TEST(lfd);
        LOAD_FLOAT_XFORM_TEST(lfdx);
        LOAD_FLOAT_DFORM_TEST(lfdu);
        LOAD_FLOAT_XFORM_TEST(lfdux);
        LOAD_FLOAT_DFORM_TEST(lfs);
        LOAD_FLOAT_XFORM_TEST(lfsx);
        LOAD_FLOAT_DFORM_TEST(lfsu);
        LOAD_FLOAT_XFORM_TEST(lfsux);
        STORE_FLOAT_DFORM_TEST(stfd);
        STORE_FLOAT_XFORM_TEST(stfdx);
        STORE_FLOAT_DFORM_TEST(stfdu);
        STORE_FLOAT_XFORM_TEST(stfdux);
        STORE_FLOAT_DFORM_TEST(stfs);
        STORE_FLOAT_XFORM_TEST(stfsx);
        STORE_FLOAT_DFORM_TEST(stfsu);
        STORE_FLOAT_XFORM_TEST(stfsux);
        STORE_FLOAT_XFORM_TEST(stfiwx);

        return rc;
}

int test_alignment_handler_fp_205(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());
        SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_05));

        printf("Floating point: 2.05\n");

        LOAD_FLOAT_DFORM_TEST(lfdp);
        LOAD_FLOAT_XFORM_TEST(lfdpx);
        LOAD_FLOAT_XFORM_TEST(lfiwax);
        STORE_FLOAT_DFORM_TEST(stfdp);
        STORE_FLOAT_XFORM_TEST(stfdpx);

        return rc;
}

int test_alignment_handler_fp_206(void)
{
        int rc = 0;

        SKIP_IF(!can_open_fb0());
        SKIP_IF(!have_hwcap(PPC_FEATURE_ARCH_2_06));

        printf("Floating point: 2.06\n");

        LOAD_FLOAT_XFORM_TEST(lfiwzx);

        return rc;
}

void usage(char *prog)
{
        printf("Usage: %s [options]\n", prog);
        printf("  -d    Enable debug error output\n");
        printf("\n");
        printf("This test requires a POWER8 or POWER9 CPU and a usable ");
        printf("framebuffer at /dev/fb0.\n");
}

int main(int argc, char *argv[])
{

        struct sigaction sa;
        int rc = 0;
        int option = 0;

        while ((option = getopt(argc, argv, "d")) != -1) {
                switch (option) {
                case 'd':
                        debug++;
                        break;
                default:
                        usage(argv[0]);
                        exit(1);
                }
        }

        bufsize = getpagesize();

        sa.sa_sigaction = sighandler;
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_SIGINFO;
        if (sigaction(SIGSEGV, &sa, NULL) == -1
            || sigaction(SIGBUS, &sa, NULL) == -1
            || sigaction(SIGILL, &sa, NULL) == -1) {
                perror("sigaction");
                exit(1);
        }

        rc |= test_harness(test_alignment_handler_vsx_206,
                           "test_alignment_handler_vsx_206");
        rc |= test_harness(test_alignment_handler_vsx_207,
                           "test_alignment_handler_vsx_207");
        rc |= test_harness(test_alignment_handler_vsx_300,
                           "test_alignment_handler_vsx_300");
        rc |= test_harness(test_alignment_handler_integer,
                           "test_alignment_handler_integer");
        rc |= test_harness(test_alignment_handler_integer_206,
                           "test_alignment_handler_integer_206");
        rc |= test_harness(test_alignment_handler_vmx,
                           "test_alignment_handler_vmx");
        rc |= test_harness(test_alignment_handler_fp,
                           "test_alignment_handler_fp");
        rc |= test_harness(test_alignment_handler_fp_205,
                           "test_alignment_handler_fp_205");
        rc |= test_harness(test_alignment_handler_fp_206,
                           "test_alignment_handler_fp_206");
        return rc;
}