src/bsp/lk/arch/x86-64/thread.c

/*
 * Copyright (c) 2009 Corey Tabaka
 * Copyright (c) 2014 Intel Corporation
 * Copyright (c) 2014 Travis Geiselbrecht
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */
#include <sys/types.h>
#include <string.h>
#include <stdlib.h>
#include <debug.h>
#include <kernel/thread.h>
#include <kernel/spinlock.h>
#include <arch/x86.h>
#include <arch/x86/descriptor.h>
#include <arch/fpu.h>

/* we're uniprocessor at this point for x86-64, so store a global pointer to the current thread */
struct thread *_current_thread;

static void initial_thread_func(void) __NO_RETURN;
static void initial_thread_func(void)
{
    int ret;

    /* release the thread lock that was implicitly held across the reschedule */
    spin_unlock(&thread_lock);
    arch_enable_ints();

    ret = _current_thread->entry(_current_thread->arg);

    thread_exit(ret);
}

void arch_thread_initialize(thread_t *t)
{
    /* create a default stack frame on the stack */
    vaddr_t stack_top = (vaddr_t)t->stack + t->stack_size;

    /* make sure the top of the stack is 8 byte aligned
              for EABI compliance */

    stack_top = ROUNDDOWN(stack_top, 8);

    struct x86_context_switch_frame *frame =
        (struct x86_context_switch_frame *)(stack_top);
    frame--;

    /* fill it in */
    memset(frame, 0, sizeof(*frame));

    frame->rip = (vaddr_t) &initial_thread_func;
    frame->rflags = 0x3002; /* IF = 0, NT = 0, IOPL = 3 */

    /* set the stack pointer */
    t->arch.rsp = (vaddr_t)frame;
#if X86_WITH_FPU
    fpu_init_thread_states(t);
#endif
}

void arch_dump_thread(thread_t *t)
{
    if (t->state != THREAD_RUNNING) {
        dprintf(INFO, "\tarch: ");
        dprintf(INFO, "sp 0x%lx\n", t->arch.rsp);
    }
}

void arch_context_switch(thread_t *oldthread, thread_t *newthread)
{
#if X86_WITH_FPU
    fpu_context_switch(oldthread, newthread);
#endif

    x86_64_context_switch(&oldthread->arch.rsp, newthread->arch.rsp);
}