// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2021 ARM Limited.
 */

#include <errno.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/auxv.h>
#include <sys/prctl.h>
#include <asm/hwcap.h>
#include <asm/sigcontext.h>
#include <asm/unistd.h>

#include "kselftest.h"

#include "syscall-abi.h"

/*
 * The kernel defines a much larger SVE_VQ_MAX than is expressable in
 * the architecture, this creates a *lot* of overhead filling the
 * buffers (especially ZA) on emulated platforms so use the actual
 * architectural maximum instead.
 */
#define ARCH_SVE_VQ_MAX 16

static int default_sme_vl;

static int sve_vl_count;
static unsigned int sve_vls[ARCH_SVE_VQ_MAX];
static int sme_vl_count;
static unsigned int sme_vls[ARCH_SVE_VQ_MAX];

extern void do_syscall(int sve_vl, int sme_vl);

static void fill_random(void *buf, size_t size)
{
        int i;
        uint32_t *lbuf = buf;

        /* random() returns a 32 bit number regardless of the size of long */
        for (i = 0; i < size / sizeof(uint32_t); i++)
                lbuf[i] = random();
}

/*
 * We also repeat the test for several syscalls to try to expose different
 * behaviour.
 */
static struct syscall_cfg {
        int syscall_nr;
        const char *name;
} syscalls[] = {
        { __NR_getpid,          "getpid()" },
        { __NR_sched_yield,     "sched_yield()" },
};

#define NUM_GPR 31
uint64_t gpr_in[NUM_GPR];
uint64_t gpr_out[NUM_GPR];

static void setup_gpr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                      uint64_t svcr)
{
        fill_random(gpr_in, sizeof(gpr_in));
        gpr_in[8] = cfg->syscall_nr;
        memset(gpr_out, 0, sizeof(gpr_out));
}

static int check_gpr(struct syscall_cfg *cfg, int sve_vl, int sme_vl, uint64_t svcr)
{
        int errors = 0;
        int i;

        /*
         * GPR x0-x7 may be clobbered, and all others should be preserved.
         */
        for (i = 9; i < ARRAY_SIZE(gpr_in); i++) {
                if (gpr_in[i] != gpr_out[i]) {
                        ksft_print_msg("%s SVE VL %d mismatch in GPR %d: %lx != %lx\n",
                                       cfg->name, sve_vl, i,
                                       gpr_in[i], gpr_out[i]);
                        errors++;
                }
        }

        return errors;
}

#define NUM_FPR 32
uint64_t fpr_in[NUM_FPR * 2];
uint64_t fpr_out[NUM_FPR * 2];
uint64_t fpr_zero[NUM_FPR * 2];

static void setup_fpr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                      uint64_t svcr)
{
        fill_random(fpr_in, sizeof(fpr_in));
        memset(fpr_out, 0, sizeof(fpr_out));
}

static int check_fpr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                     uint64_t svcr)
{
        int errors = 0;
        int i;

        if (!sve_vl && !(svcr & SVCR_SM_MASK)) {
                for (i = 0; i < ARRAY_SIZE(fpr_in); i++) {
                        if (fpr_in[i] != fpr_out[i]) {
                                ksft_print_msg("%s Q%d/%d mismatch %lx != %lx\n",
                                               cfg->name,
                                               i / 2, i % 2,
                                               fpr_in[i], fpr_out[i]);
                                errors++;
                        }
                }
        }

        /*
         * In streaming mode the whole register set should be cleared
         * by the transition out of streaming mode.
         */
        if (svcr & SVCR_SM_MASK) {
                if (memcmp(fpr_zero, fpr_out, sizeof(fpr_out)) != 0) {
                        ksft_print_msg("%s FPSIMD registers non-zero exiting SM\n",
                                       cfg->name);
                        errors++;
                }
        }

        return errors;
}

#define SVE_Z_SHARED_BYTES (128 / 8)

static uint8_t z_zero[__SVE_ZREG_SIZE(ARCH_SVE_VQ_MAX)];
uint8_t z_in[SVE_NUM_ZREGS * __SVE_ZREG_SIZE(ARCH_SVE_VQ_MAX)];
uint8_t z_out[SVE_NUM_ZREGS * __SVE_ZREG_SIZE(ARCH_SVE_VQ_MAX)];

static void setup_z(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                    uint64_t svcr)
{
        fill_random(z_in, sizeof(z_in));
        fill_random(z_out, sizeof(z_out));
}

static int check_z(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                   uint64_t svcr)
{
        size_t reg_size = sve_vl;
        int errors = 0;
        int i;

        if (!sve_vl)
                return 0;

        for (i = 0; i < SVE_NUM_ZREGS; i++) {
                uint8_t *in = &z_in[reg_size * i];
                uint8_t *out = &z_out[reg_size * i];

                if (svcr & SVCR_SM_MASK) {
                        /*
                         * In streaming mode the whole register should
                         * be cleared by the transition out of
                         * streaming mode.
                         */
                        if (memcmp(z_zero, out, reg_size) != 0) {
                                ksft_print_msg("%s SVE VL %d Z%d non-zero\n",
                                               cfg->name, sve_vl, i);
                                errors++;
                        }
                } else {
                        /*
                         * For standard SVE the low 128 bits should be
                         * preserved and any additional bits cleared.
                         */
                        if (memcmp(in, out, SVE_Z_SHARED_BYTES) != 0) {
                                ksft_print_msg("%s SVE VL %d Z%d low 128 bits changed\n",
                                               cfg->name, sve_vl, i);
                                errors++;
                        }

                        if (reg_size > SVE_Z_SHARED_BYTES &&
                            (memcmp(z_zero, out + SVE_Z_SHARED_BYTES,
                                    reg_size - SVE_Z_SHARED_BYTES) != 0)) {
                                ksft_print_msg("%s SVE VL %d Z%d high bits non-zero\n",
                                               cfg->name, sve_vl, i);
                                errors++;
                        }
                }
        }

        return errors;
}

uint8_t p_in[SVE_NUM_PREGS * __SVE_PREG_SIZE(ARCH_SVE_VQ_MAX)];
uint8_t p_out[SVE_NUM_PREGS * __SVE_PREG_SIZE(ARCH_SVE_VQ_MAX)];

static void setup_p(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                    uint64_t svcr)
{
        fill_random(p_in, sizeof(p_in));
        fill_random(p_out, sizeof(p_out));
}

static int check_p(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                   uint64_t svcr)
{
        size_t reg_size = sve_vq_from_vl(sve_vl) * 2; /* 1 bit per VL byte */

        int errors = 0;
        int i;

        if (!sve_vl)
                return 0;

        /* After a syscall the P registers should be zeroed */
        for (i = 0; i < SVE_NUM_PREGS * reg_size; i++)
                if (p_out[i])
                        errors++;
        if (errors)
                ksft_print_msg("%s SVE VL %d predicate registers non-zero\n",
                               cfg->name, sve_vl);

        return errors;
}

uint8_t ffr_in[__SVE_PREG_SIZE(ARCH_SVE_VQ_MAX)];
uint8_t ffr_out[__SVE_PREG_SIZE(ARCH_SVE_VQ_MAX)];

static void setup_ffr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                      uint64_t svcr)
{
        /*
         * If we are in streaming mode and do not have FA64 then FFR
         * is unavailable.
         */
        if ((svcr & SVCR_SM_MASK) &&
            !(getauxval(AT_HWCAP2) & HWCAP2_SME_FA64)) {
                memset(&ffr_in, 0, sizeof(ffr_in));
                return;
        }

        /*
         * It is only valid to set a contiguous set of bits starting
         * at 0.  For now since we're expecting this to be cleared by
         * a syscall just set all bits.
         */
        memset(ffr_in, 0xff, sizeof(ffr_in));
        fill_random(ffr_out, sizeof(ffr_out));
}

static int check_ffr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                     uint64_t svcr)
{
        size_t reg_size = sve_vq_from_vl(sve_vl) * 2;  /* 1 bit per VL byte */
        int errors = 0;
        int i;

        if (!sve_vl)
                return 0;

        if ((svcr & SVCR_SM_MASK) &&
            !(getauxval(AT_HWCAP2) & HWCAP2_SME_FA64))
                return 0;

        /* After a syscall FFR should be zeroed */
        for (i = 0; i < reg_size; i++)
                if (ffr_out[i])
                        errors++;
        if (errors)
                ksft_print_msg("%s SVE VL %d FFR non-zero\n",
                               cfg->name, sve_vl);

        return errors;
}

uint64_t svcr_in, svcr_out;

static void setup_svcr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                    uint64_t svcr)
{
        svcr_in = svcr;
}

static int check_svcr(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                      uint64_t svcr)
{
        int errors = 0;

        if (svcr_out & SVCR_SM_MASK) {
                ksft_print_msg("%s Still in SM, SVCR %lx\n",
                               cfg->name, svcr_out);
                errors++;
        }

        if ((svcr_in & SVCR_ZA_MASK) != (svcr_out & SVCR_ZA_MASK)) {
                ksft_print_msg("%s PSTATE.ZA changed, SVCR %lx != %lx\n",
                               cfg->name, svcr_in, svcr_out);
                errors++;
        }

        return errors;
}

uint8_t za_in[ZA_SIG_REGS_SIZE(ARCH_SVE_VQ_MAX)];
uint8_t za_out[ZA_SIG_REGS_SIZE(ARCH_SVE_VQ_MAX)];

static void setup_za(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                     uint64_t svcr)
{
        fill_random(za_in, sizeof(za_in));
        memset(za_out, 0, sizeof(za_out));
}

static int check_za(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                    uint64_t svcr)
{
        size_t reg_size = sme_vl * sme_vl;
        int errors = 0;

        if (!(svcr & SVCR_ZA_MASK))
                return 0;

        if (memcmp(za_in, za_out, reg_size) != 0) {
                ksft_print_msg("SME VL %d ZA does not match\n", sme_vl);
                errors++;
        }

        return errors;
}

uint8_t zt_in[ZT_SIG_REG_BYTES] __attribute__((aligned(16)));
uint8_t zt_out[ZT_SIG_REG_BYTES] __attribute__((aligned(16)));

static void setup_zt(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                     uint64_t svcr)
{
        fill_random(zt_in, sizeof(zt_in));
        memset(zt_out, 0, sizeof(zt_out));
}

static int check_zt(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                    uint64_t svcr)
{
        int errors = 0;

        if (!(getauxval(AT_HWCAP2) & HWCAP2_SME2))
                return 0;

        if (!(svcr & SVCR_ZA_MASK))
                return 0;

        if (memcmp(zt_in, zt_out, sizeof(zt_in)) != 0) {
                ksft_print_msg("SME VL %d ZT does not match\n", sme_vl);
                errors++;
        }

        return errors;
}

typedef void (*setup_fn)(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                         uint64_t svcr);
typedef int (*check_fn)(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                        uint64_t svcr);

/*
 * Each set of registers has a setup function which is called before
 * the syscall to fill values in a global variable for loading by the
 * test code and a check function which validates that the results are
 * as expected.  Vector lengths are passed everywhere, a vector length
 * of 0 should be treated as do not test.
 */
static struct {
        setup_fn setup;
        check_fn check;
} regset[] = {
        { setup_gpr, check_gpr },
        { setup_fpr, check_fpr },
        { setup_z, check_z },
        { setup_p, check_p },
        { setup_ffr, check_ffr },
        { setup_svcr, check_svcr },
        { setup_za, check_za },
        { setup_zt, check_zt },
};

static bool do_test(struct syscall_cfg *cfg, int sve_vl, int sme_vl,
                    uint64_t svcr)
{
        int errors = 0;
        int i;

        for (i = 0; i < ARRAY_SIZE(regset); i++)
                regset[i].setup(cfg, sve_vl, sme_vl, svcr);

        do_syscall(sve_vl, sme_vl);

        for (i = 0; i < ARRAY_SIZE(regset); i++)
                errors += regset[i].check(cfg, sve_vl, sme_vl, svcr);

        return errors == 0;
}

static void test_one_syscall(struct syscall_cfg *cfg)
{
        int sve, sme;
        int ret;

        /* FPSIMD only case */
        ksft_test_result(do_test(cfg, 0, default_sme_vl, 0),
                         "%s FPSIMD\n", cfg->name);

        for (sve = 0; sve < sve_vl_count; sve++) {
                ret = prctl(PR_SVE_SET_VL, sve_vls[sve]);
                if (ret == -1)
                        ksft_exit_fail_msg("PR_SVE_SET_VL failed: %s (%d)\n",
                                           strerror(errno), errno);

                ksft_test_result(do_test(cfg, sve_vls[sve], default_sme_vl, 0),
                                 "%s SVE VL %d\n", cfg->name, sve_vls[sve]);

                for (sme = 0; sme < sme_vl_count; sme++) {
                        ret = prctl(PR_SME_SET_VL, sme_vls[sme]);
                        if (ret == -1)
                                ksft_exit_fail_msg("PR_SME_SET_VL failed: %s (%d)\n",
                                                   strerror(errno), errno);

                        ksft_test_result(do_test(cfg, sve_vls[sve],
                                                 sme_vls[sme],
                                                 SVCR_ZA_MASK | SVCR_SM_MASK),
                                         "%s SVE VL %d/SME VL %d SM+ZA\n",
                                         cfg->name, sve_vls[sve],
                                         sme_vls[sme]);
                        ksft_test_result(do_test(cfg, sve_vls[sve],
                                                 sme_vls[sme], SVCR_SM_MASK),
                                         "%s SVE VL %d/SME VL %d SM\n",
                                         cfg->name, sve_vls[sve],
                                         sme_vls[sme]);
                        ksft_test_result(do_test(cfg, sve_vls[sve],
                                                 sme_vls[sme], SVCR_ZA_MASK),
                                         "%s SVE VL %d/SME VL %d ZA\n",
                                         cfg->name, sve_vls[sve],
                                         sme_vls[sme]);
                }
        }

        for (sme = 0; sme < sme_vl_count; sme++) {
                ret = prctl(PR_SME_SET_VL, sme_vls[sme]);
                if (ret == -1)
                        ksft_exit_fail_msg("PR_SME_SET_VL failed: %s (%d)\n",
                                                   strerror(errno), errno);

                ksft_test_result(do_test(cfg, 0, sme_vls[sme],
                                         SVCR_ZA_MASK | SVCR_SM_MASK),
                                 "%s SME VL %d SM+ZA\n",
                                 cfg->name, sme_vls[sme]);
                ksft_test_result(do_test(cfg, 0, sme_vls[sme], SVCR_SM_MASK),
                                 "%s SME VL %d SM\n",
                                 cfg->name, sme_vls[sme]);
                ksft_test_result(do_test(cfg, 0, sme_vls[sme], SVCR_ZA_MASK),
                                 "%s SME VL %d ZA\n",
                                 cfg->name, sme_vls[sme]);
        }
}

void sve_count_vls(void)
{
        unsigned int vq;
        int vl;

        if (!(getauxval(AT_HWCAP) & HWCAP_SVE))
                return;

        /*
         * Enumerate up to ARCH_SVE_VQ_MAX vector lengths
         */
        for (vq = ARCH_SVE_VQ_MAX; vq > 0; vq /= 2) {
                vl = prctl(PR_SVE_SET_VL, vq * 16);
                if (vl == -1)
                        ksft_exit_fail_msg("PR_SVE_SET_VL failed: %s (%d)\n",
                                           strerror(errno), errno);

                vl &= PR_SVE_VL_LEN_MASK;

                if (vq != sve_vq_from_vl(vl))
                        vq = sve_vq_from_vl(vl);

                sve_vls[sve_vl_count++] = vl;
        }
}

void sme_count_vls(void)
{
        unsigned int vq;
        int vl;

        if (!(getauxval(AT_HWCAP2) & HWCAP2_SME))
                return;

        /*
         * Enumerate up to ARCH_SVE_VQ_MAX vector lengths
         */
        for (vq = ARCH_SVE_VQ_MAX; vq > 0; vq /= 2) {
                vl = prctl(PR_SME_SET_VL, vq * 16);
                if (vl == -1)
                        ksft_exit_fail_msg("PR_SME_SET_VL failed: %s (%d)\n",
                                           strerror(errno), errno);

                vl &= PR_SME_VL_LEN_MASK;

                /* Found lowest VL */
                if (sve_vq_from_vl(vl) > vq)
                        break;

                if (vq != sve_vq_from_vl(vl))
                        vq = sve_vq_from_vl(vl);

                sme_vls[sme_vl_count++] = vl;
        }

        /* Ensure we configure a SME VL, used to flag if SVCR is set */
        default_sme_vl = sme_vls[0];
}

int main(void)
{
        int i;
        int tests = 1;  /* FPSIMD */
        int sme_ver;

        srandom(getpid());

        ksft_print_header();

        sve_count_vls();
        sme_count_vls();

        tests += sve_vl_count;
        tests += sme_vl_count * 3;
        tests += (sve_vl_count * sme_vl_count) * 3;
        ksft_set_plan(ARRAY_SIZE(syscalls) * tests);

        if (getauxval(AT_HWCAP2) & HWCAP2_SME2)
                sme_ver = 2;
        else
                sme_ver = 1;

        if (getauxval(AT_HWCAP2) & HWCAP2_SME_FA64)
                ksft_print_msg("SME%d with FA64\n", sme_ver);
        else if (getauxval(AT_HWCAP2) & HWCAP2_SME)
                ksft_print_msg("SME%d without FA64\n", sme_ver);

        for (i = 0; i < ARRAY_SIZE(syscalls); i++)
                test_one_syscall(&syscalls[i]);

        ksft_print_cnts();

        return 0;
}