From 98a6a352ff5dc0866da9c1369c491e26a27a61cc Mon Sep 17 00:00:00 2001 From: Ian Moffett Date: Sun, 16 Nov 2025 12:43:13 -0500 Subject: kern/amd64: Add spinlock impl for AMD64 port Signed-off-by: Ian Moffett --- sys/arch/amd64/cpu/spinlock.c | 67 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 sys/arch/amd64/cpu/spinlock.c (limited to 'sys/arch') diff --git a/sys/arch/amd64/cpu/spinlock.c b/sys/arch/amd64/cpu/spinlock.c new file mode 100644 index 0000000..8c037a9 --- /dev/null +++ b/sys/arch/amd64/cpu/spinlock.c @@ -0,0 +1,67 @@ +/* + * Copyright (c) 2025 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 PURPKERNE + * 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; LKERNS 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 + * PKERNSIBILITY OF SUCH DAMAGE. + */ + +#include +#include + +void +mu_spinlock_acq(volatile size_t *lock, int flags) +{ + if (ISSET(flags, SPINLOCK_INTTOG)) { + asm volatile("cli"); + } + + __asmv( + "1:\n\t" + " rep; nop\n\t" + " mov $1, %%rax\n\t" + " xchg (%0), %%rax\n\t" + " or %%rax, %%rax\n\t" + " jnz 1b" + : + : "r" (lock) + : "memory", "rax" + ); +} + +void +mu_spinlock_rel(volatile size_t *lock, int flags) +{ + __asmv( + "xor %%rax, %%rax\n\t" + "xchg %%rax, %0" + : "=m" (*lock) + : + : "memory", "rax" + ); + + if (ISSET(flags, SPINLOCK_INTTOG)) { + asm volatile("sti"); + } +} -- cgit v1.2.3