tests/tcg/aarch64: add DC CVA[D]P tests

Test execution of DC CVAP and DC CVADP instructions under user mode
emulation.

Signed-off-by: Zhuojia Shen <chaosdefinition@hotmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

tests/tcg/aarch64/dcpop.c

@@ -0,0 +1,63 @@
+/*
+ * Test execution of DC CVAP instruction.
+ *
+ * Copyright (c) 2023 Zhuojia Shen <chaosdefinition@hotmail.com>
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include <asm/hwcap.h>
+#include <sys/auxv.h>
+
+#include <signal.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef HWCAP_DCPOP
+#define HWCAP_DCPOP (1 << 16)
+#endif
+
+bool should_fail = false;
+
+static void signal_handler(int sig, siginfo_t *si, void *data)
+{
+    ucontext_t *uc = (ucontext_t *)data;
+
+    if (should_fail) {
+        uc->uc_mcontext.pc += 4;
+    } else {
+        exit(EXIT_FAILURE);
+    }
+}
+
+static int do_dc_cvap(void)
+{
+    struct sigaction sa = {
+        .sa_flags = SA_SIGINFO,
+        .sa_sigaction = signal_handler,
+    };
+
+    sigemptyset(&sa.sa_mask);
+    if (sigaction(SIGSEGV, &sa, NULL) < 0) {
+        perror("sigaction");
+        return EXIT_FAILURE;
+    }
+
+    asm volatile("dc cvap, %0\n\t" :: "r"(&sa));
+
+    should_fail = true;
+    asm volatile("dc cvap, %0\n\t" :: "r"(NULL));
+    should_fail = false;
+
+    return EXIT_SUCCESS;
+}
+
+int main(void)
+{
+    if (getauxval(AT_HWCAP) & HWCAP_DCPOP) {
+        return do_dc_cvap();
+    } else {
+        printf("SKIP: no HWCAP_DCPOP on this system\n");
+        return EXIT_SUCCESS;
+    }
+}