You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

248 lines
6.7 KiB

/*
* Copyright (C) 2016 Kaspar Schleiser <kaspar@schleiser.de>
* 2013 Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @ingroup native_cpu
* @{
*
* @file
* @brief Native CPU kernel_intern.h and sched.h implementation
*
* in-process preemptive context switching utilizes POSIX ucontexts.
* (ucontext provides for architecture independent stack handling)
*
* @author Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
* @author Kaspar Schleiser <kaspar@schleiser.de>
*/
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#define __USE_GNU
#include <signal.h>
#undef __USE_GNU
#include <ucontext.h>
#include <err.h>
#ifdef HAVE_VALGRIND_H
#include <valgrind.h>
#define VALGRIND_DEBUG DEBUG
#elif defined(HAVE_VALGRIND_VALGRIND_H)
#include <valgrind/valgrind.h>
#define VALGRIND_DEBUG DEBUG
#else
#define VALGRIND_STACK_REGISTER(...)
#define VALGRIND_DEBUG(...)
#endif
#include <stdlib.h>
#include "irq.h"
#include "sched.h"
#include "cpu.h"
#include "cpu_conf.h"
#ifdef MODULE_NETDEV_TAP
#include "netdev_tap.h"
extern netdev_tap_t netdev_tap;
#endif
#include "native_internal.h"
#define ENABLE_DEBUG (0)
#include "debug.h"
ucontext_t end_context;
char __end_stack[SIGSTKSZ];
/**
* make the new context assign `_native_in_isr = 0` before resuming
*/
static void _native_mod_ctx_leave_sigh(ucontext_t *ctx)
{
#ifdef __MACH__
_native_saved_eip = ((ucontext_t *)ctx)->uc_mcontext->__ss.__eip;
((ucontext_t *)ctx)->uc_mcontext->__ss.__eip = (unsigned int)&_native_sig_leave_handler;
#elif defined(__FreeBSD__)
_native_saved_eip = ((struct sigcontext *)ctx)->sc_eip;
((struct sigcontext *)ctx)->sc_eip = (unsigned int)&_native_sig_leave_handler;
#else /* Linux */
#if defined(__arm__)
_native_saved_eip = ((ucontext_t *)ctx)->uc_mcontext.arm_pc;
((ucontext_t *)ctx)->uc_mcontext.arm_pc = (unsigned int)&_native_sig_leave_handler;
#else /* Linux/x86 */
_native_saved_eip = ctx->uc_mcontext.gregs[REG_EIP];
ctx->uc_mcontext.gregs[REG_EIP] = (unsigned int)&_native_sig_leave_handler;
#endif
#endif
}
/**
* TODO: implement
*/
void thread_print_stack(void)
{
DEBUG("thread_print_stack\n");
return;
}
/* This function calculates the ISR_usage */
int thread_arch_isr_stack_usage(void)
{
/* TODO */
return -1;
}
char *thread_stack_init(thread_task_func_t task_func, void *arg, void *stack_start, int stacksize)
{
char *stk;
ucontext_t *p;
VALGRIND_STACK_REGISTER(stack_start, (char *) stack_start + stacksize);
VALGRIND_DEBUG("VALGRIND_STACK_REGISTER(%p, %p)\n",
stack_start, (void*)((int)stack_start + stacksize));
DEBUG("thread_stack_init\n");
stk = stack_start;
p = (ucontext_t *)(stk + (stacksize - sizeof(ucontext_t)));
stacksize -= sizeof(ucontext_t);
if (getcontext(p) == -1) {
err(EXIT_FAILURE, "thread_stack_init: getcontext");
}
p->uc_stack.ss_sp = stk;
p->uc_stack.ss_size = stacksize;
p->uc_stack.ss_flags = 0;
p->uc_link = &end_context;
if (sigemptyset(&(p->uc_sigmask)) == -1) {
err(EXIT_FAILURE, "thread_stack_init: sigemptyset");
}
makecontext(p, (void (*)(void)) task_func, 1, arg);
return (char *) p;
}
void isr_cpu_switch_context_exit(void)
{
ucontext_t *ctx;
DEBUG("isr_cpu_switch_context_exit\n");
if ((sched_context_switch_request == 1) || (sched_active_thread == NULL)) {
sched_run();
}
DEBUG("isr_cpu_switch_context_exit: calling setcontext(%" PRIkernel_pid ")\n\n", sched_active_pid);
ctx = (ucontext_t *)(sched_active_thread->sp);
native_interrupts_enabled = 1;
_native_mod_ctx_leave_sigh(ctx);
if (setcontext(ctx) == -1) {
err(EXIT_FAILURE, "isr_cpu_switch_context_exit: setcontext");
}
errx(EXIT_FAILURE, "2 this should have never been reached!!");
}
void cpu_switch_context_exit(void)
{
#ifdef NATIVE_AUTO_EXIT
if (sched_num_threads <= 1) {
DEBUG("cpu_switch_context_exit: last task has ended. exiting.\n");
real_exit(EXIT_SUCCESS);
}
#endif
if (_native_in_isr == 0) {
irq_disable();
_native_in_isr = 1;
native_isr_context.uc_stack.ss_sp = __isr_stack;
native_isr_context.uc_stack.ss_size = sizeof(__isr_stack);
native_isr_context.uc_stack.ss_flags = 0;
makecontext(&native_isr_context, isr_cpu_switch_context_exit, 0);
if (setcontext(&native_isr_context) == -1) {
err(EXIT_FAILURE, "cpu_switch_context_exit: setcontext");
}
errx(EXIT_FAILURE, "1 this should have never been reached!!");
}
else {
isr_cpu_switch_context_exit();
}
errx(EXIT_FAILURE, "3 this should have never been reached!!");
}
void isr_thread_yield(void)
{
DEBUG("isr_thread_yield\n");
if (_native_sigpend > 0) {
DEBUG("isr_thread_yield(): handling signals\n\n");
native_irq_handler();
}
sched_run();
ucontext_t *ctx = (ucontext_t *)(sched_active_thread->sp);
DEBUG("isr_thread_yield: switching to(%" PRIkernel_pid ")\n\n", sched_active_pid);
native_interrupts_enabled = 1;
_native_mod_ctx_leave_sigh(ctx);
if (setcontext(ctx) == -1) {
err(EXIT_FAILURE, "isr_thread_yield: setcontext");
}
}
void thread_yield_higher(void)
{
if (_native_in_isr == 0) {
ucontext_t *ctx = (ucontext_t *)(sched_active_thread->sp);
_native_in_isr = 1;
if (!native_interrupts_enabled) {
warnx("thread_yield_higher: interrupts are disabled - this should not be");
}
irq_disable();
native_isr_context.uc_stack.ss_sp = __isr_stack;
native_isr_context.uc_stack.ss_size = SIGSTKSZ;
native_isr_context.uc_stack.ss_flags = 0;
makecontext(&native_isr_context, isr_thread_yield, 0);
if (swapcontext(ctx, &native_isr_context) == -1) {
err(EXIT_FAILURE, "thread_yield_higher: swapcontext");
}
irq_enable();
}
else {
sched_context_switch_request = 1;
}
}
void native_cpu_init(void)
{
if (getcontext(&end_context) == -1) {
err(EXIT_FAILURE, "native_cpu_init: getcontext");
}
end_context.uc_stack.ss_sp = __end_stack;
end_context.uc_stack.ss_size = SIGSTKSZ;
end_context.uc_stack.ss_flags = 0;
makecontext(&end_context, sched_task_exit, 0);
VALGRIND_STACK_REGISTER(__end_stack, __end_stack + sizeof(__end_stack));
VALGRIND_DEBUG("VALGRIND_STACK_REGISTER(%p, %p)\n",
(void*)__end_stack, (void*)((int)__end_stack + sizeof(__end_stack)));
DEBUG("RIOT native cpu initialized.\n");
}
/** @} */