// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2022 ARM Limited
 *
 * Verify that the TPIDR2 register context in signal frames is set up as
 * expected.
 */

#include <signal.h>
#include <ucontext.h>
#include <sys/auxv.h>
#include <sys/prctl.h>
#include <unistd.h>
#include <asm/sigcontext.h>

#include "test_signals_utils.h"
#include "testcases.h"

static union {
        ucontext_t uc;
        char buf[1024 * 128];
} context;

#define SYS_TPIDR2 "S3_3_C13_C0_5"

static uint64_t get_tpidr2(void)
{
        uint64_t val;

        asm volatile (
                "mrs    %0, " SYS_TPIDR2 "\n"
                : "=r"(val)
                :
                : "cc");

        return val;
}

int tpidr2_present(struct tdescr *td, siginfo_t *si, ucontext_t *uc)
{
        struct _aarch64_ctx *head = GET_BUF_RESV_HEAD(context);
        struct tpidr2_context *tpidr2_ctx;
        size_t offset;
        bool in_sigframe;
        bool have_sme;
        __u64 orig_tpidr2;

        have_sme = getauxval(AT_HWCAP2) & HWCAP2_SME;
        if (have_sme)
                orig_tpidr2 = get_tpidr2();

        if (!get_current_context(td, &context.uc, sizeof(context)))
                return 1;

        tpidr2_ctx = (struct tpidr2_context *)
                get_header(head, TPIDR2_MAGIC, td->live_sz, &offset);

        in_sigframe = tpidr2_ctx != NULL;

        fprintf(stderr, "TPIDR2 sigframe %s on system %s SME\n",
                in_sigframe ? "present" : "absent",
                have_sme ? "with" : "without");

        td->pass = (in_sigframe == have_sme);

        /*
         * Check that the value we read back was the one present at
         * the time that the signal was triggered.  TPIDR2 is owned by
         * libc so we can't safely choose the value and it is possible
         * that we may need to revisit this in future if something
         * starts deciding to set a new TPIDR2 between us reading and
         * the signal.
         */
        if (have_sme && tpidr2_ctx) {
                if (tpidr2_ctx->tpidr2 != orig_tpidr2) {
                        fprintf(stderr, "TPIDR2 in frame is %llx, was %llx\n",
                                tpidr2_ctx->tpidr2, orig_tpidr2);
                        td->pass = false;
                }
        }

        return 0;
}

struct tdescr tde = {
        .name = "TPIDR2",
        .descr = "Validate that TPIDR2 is present as expected",
        .timeout = 3,
        .run = tpidr2_present,
};