From e0928e6ddf94c25f026d02643ddd0a2016ddd17b Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sun, 15 Dec 2024 22:49:50 -0500 Subject: kernel: synch: Add spinlock with timeout Signed-off-by: Ian Moffett --- sys/kern/kern_synch.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 73 insertions(+) create mode 100644 sys/kern/kern_synch.c (limited to 'sys/kern') diff --git a/sys/kern/kern_synch.c b/sys/kern/kern_synch.c new file mode 100644 index 0000000..1b78642 --- /dev/null +++ b/sys/kern/kern_synch.c @@ -0,0 +1,73 @@ +/* + * Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * + * 1. Redistributions of source code must retain the above copyright notice, + * this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of Hyra nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" + * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE + * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR + * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF + * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS + * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN + * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + */ + +#include +#include +#include +#include +#include + +#define pr_trace(fmt, ...) kprintf("synch: " fmt, ##__VA_ARGS__) +#define pr_error(...) pr_trace(__VA_ARGS__) + +/* + * Returns 0 on success, returns non-zero value + * on timeout/failure. + */ +int +spinlock_usleep(struct spinlock *lock, size_t usec_max) +{ + struct timer tmr; + size_t usec_start, usec_cur; + size_t usec_elap; + int err; + + if ((err = req_timer(TIMER_GP, &tmr)) != 0) { + pr_error("spinlock_usleep: req_timer() returned %d\n", err); + pr_error("spinlock_usleep: Failed to request timer...\n"); + return err; + } + + if (tmr.get_time_usec == NULL) { + pr_error("spinlock_usleep: Timer does not have get_time_usec()\n"); + return -ENOTSUP; + } + + usec_start = tmr.get_time_usec(); + while (__atomic_test_and_set(&lock->lock, __ATOMIC_ACQUIRE)) { + usec_cur = tmr.get_time_usec(); + usec_elap = (usec_cur - usec_start); + + if (usec_elap > usec_max) { + return -1; + } + } + + return 0; +} -- cgit v1.2.3