diff options
| -rw-r--r-- | kern/xcall.c | 27 |
1 files changed, 13 insertions, 14 deletions
diff --git a/kern/xcall.c b/kern/xcall.c index b3b01e2b..364ad0be 100644 --- a/kern/xcall.c +++ b/kern/xcall.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2014 Richard Braun. + * Copyright (c) 2014-2017 Richard Braun. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -18,13 +18,13 @@ #include <stddef.h> #include <kern/assert.h> +#include <kern/atomic.h> #include <kern/macros.h> #include <kern/param.h> #include <kern/percpu.h> #include <kern/spinlock.h> #include <kern/thread.h> #include <kern/xcall.h> -#include <machine/mb.h> #include <machine/cpu.h> struct xcall { @@ -86,15 +86,21 @@ xcall_cpu_data_get_send_call(struct xcall_cpu_data *cpu_data, unsigned int cpu) } static struct xcall * -xcall_cpu_data_get_recv_call(struct xcall_cpu_data *cpu_data) +xcall_cpu_data_get_recv_call(const struct xcall_cpu_data *cpu_data) { - return cpu_data->recv_call; + return atomic_load(&cpu_data->recv_call, ATOMIC_ACQUIRE); +} + +static void +xcall_cpu_data_set_recv_call(struct xcall_cpu_data *cpu_data, struct xcall *call) +{ + atomic_store(&cpu_data->recv_call, call, ATOMIC_RELEASE); } static void xcall_cpu_data_clear_recv_call(struct xcall_cpu_data *cpu_data) { - cpu_data->recv_call = NULL; + xcall_cpu_data_set_recv_call(cpu_data, NULL); } void @@ -134,22 +140,16 @@ xcall_call(xcall_fn_t fn, void *arg, unsigned int cpu) spinlock_lock(&remote_data->lock); - remote_data->recv_call = call; - - /* This barrier pairs with the one implied by the received IPI */ - mb_store(); + xcall_cpu_data_set_recv_call(remote_data, call); cpu_send_xcall(cpu); - while (remote_data->recv_call != NULL) { + while (xcall_cpu_data_get_recv_call(remote_data) != NULL) { cpu_pause(); } spinlock_unlock(&remote_data->lock); - /* This barrier pairs with the one in the interrupt handler */ - mb_load(); - out: thread_preempt_enable(); } @@ -165,6 +165,5 @@ xcall_intr(void) cpu_data = xcall_cpu_data_get(); call = xcall_cpu_data_get_recv_call(cpu_data); call->fn(call->arg); - mb_store(); xcall_cpu_data_clear_recv_call(cpu_data); } |