1 /* 2 * Simple Virtual Timer Test 3 * 4 * Copyright (c) 2020 Linaro Ltd 5 * 6 * SPDX-License-Identifier: GPL-2.0-or-later 7 */ 8 9 #include <stdint.h> 10 #include <minilib.h> 11 12 /* grabbed from Linux */ 13 #define __stringify_1(x...) #x 14 #define __stringify(x...) __stringify_1(x) 15 16 #define read_sysreg(r) ({ \ 17 uint64_t __val; \ 18 asm volatile("mrs %0, " __stringify(r) : "=r" (__val)); \ 19 __val; \ 20 }) 21 22 #define write_sysreg(r, v) do { \ 23 uint64_t __val = (uint64_t)(v); \ 24 asm volatile("msr " __stringify(r) ", %x0" \ 25 : : "rZ" (__val)); \ 26 } while (0) 27 28 int main(void) 29 { 30 int i; 31 32 ml_printf("VTimer Test\n"); 33 34 write_sysreg(cntvoff_el2, 1); 35 write_sysreg(cntv_cval_el0, -1); 36 write_sysreg(cntv_ctl_el0, 1); 37 38 ml_printf("cntvoff_el2=%lx\n", read_sysreg(cntvoff_el2)); 39 ml_printf("cntv_cval_el0=%lx\n", read_sysreg(cntv_cval_el0)); 40 ml_printf("cntv_ctl_el0=%lx\n", read_sysreg(cntv_ctl_el0)); 41 42 /* Now read cval a few times */ 43 for (i = 0; i < 10; i++) { 44 ml_printf("%d: cntv_cval_el0=%lx\n", i, read_sysreg(cntv_cval_el0)); 45 } 46 47 return 0; 48 } 49