1 /* 2 * This file and its contents are supplied under the terms of the 3 * Common Development and Distribution License ("CDDL"), version 1.0. 4 * You may only use this file in accordance with the terms of version 5 * 1.0 of the CDDL. 6 * 7 * A full copy of the text of the CDDL should have accompanied this 8 * source. A copy of the CDDL is also available via the Internet at 9 * http://www.illumos.org/license/CDDL. 10 */ 11 12 /* 13 * Copyright 2023 Oxide Computer Company 14 */ 15 16 #include "payload_common.h" 17 #include "payload_utils.h" 18 19 #define UINT32_MAX 0xffffffff 20 21 void 22 start(void) 23 { 24 /* read the period */ 25 uint32_t period = inl(IOP_TEST_VALUE); 26 27 /* loop for as long as the host wants */ 28 for (;;) { 29 uint64_t start, end; 30 start = rdtsc(); 31 outl(IOP_TEST_VALUE, UINT32_MAX & start); 32 outl(IOP_TEST_VALUE, UINT32_MAX & (start >> 32)); 33 34 do { 35 end = rdtsc(); 36 /* wait for enough ticks to pass */ 37 } while ((end - start) < period); 38 } 39 } 40