/*
* Copyright (c) 2001-2004 Jakub Jermar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - 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.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
/** @addtogroup kernel_generic
* @{
*/
/** @file
*/
#ifndef KERN_CONTEXT_H_
#define KERN_CONTEXT_H_
#include <panic.h>
#include <trace.h>
#include <arch/context.h>
#include <arch/faddr.h>
#define context_set_generic(ctx, _pc, stack, size) \
do { \
(ctx)->pc = (uintptr_t) (_pc); \
(ctx)->sp = ((uintptr_t) (stack)) + (size) - SP_DELTA; \
} while (0)
extern int context_save_arch(context_t *ctx) __attribute__((returns_twice));
extern void context_restore_arch(context_t *ctx) __attribute__((noreturn));
/** Restore register context.
*
* Restore a previously saved register context (including stack pointer) from
* a context structure.
*
* Note that this function does not normally return. Instead, it returns to the
* same address as the corresponding call to context_save(), the only difference
* being return value.
*
* @param ctx Context structure.
*
*/
_NO_TRACE __attribute__((noreturn))
static inline void context_restore(context_t *ctx)
{
context_restore_arch(ctx);
}
/**
* Saves current context to the variable pointed to by `self`,
* and restores the context denoted by `other`.
*
* When the `self` context is later restored by another call to
* `context_swap()`, the control flow behaves as if the earlier call to
* `context_swap()` just returned.
*/
_NO_TRACE static inline void context_swap(context_t *self, context_t *other)
{
if (context_save_arch(self))
context_restore_arch(other);
}
_NO_TRACE static inline void context_create(context_t *context,
void (*fn)(void), void *stack_base, size_t stack_size)
{
*context = (context_t) { 0 };
context_set(context, FADDR(fn), stack_base, stack_size);
}
__attribute__((noreturn)) static inline void context_replace(void (*fn)(void),
void *stack_base, size_t stack_size)
{
context_t ctx;
context_create(&ctx, fn, stack_base, stack_size);
context_restore(&ctx);
}
#endif
/** @}
*/