#ifndef KERNEL_X86_64_THREAD_H_
#define KERNEL_X86_64_THREAD_H_

#include <kernel/sched.h>

struct ml_cpu_context;

/* switch from one thread to another. the stack of the `to` thread must have
 * been prepared in one of two ways:
 *  1) a previous call to ml_thread_switch where it was the `from` thread.
 *  2) a call to ml_thread_prepare_kernel_context
 * the switch occurs entirely with kernel mode. a further return from an
 * interrupt context is then used to return to usermode if necessary.
 */
extern void ml_thread_switch(struct thread *from, struct thread *to);

/* perform the initial transition to userspace. the stack must be prepared using
 * ml_thread_prepare_user_context before this function can be used */
extern void ml_thread_switch_user(void);
/* prepare the stack so that ml_thread_switch can jump to the specified IP/SP */
extern void ml_thread_prepare_kernel_context(uintptr_t ip, uintptr_t *sp);
/* prepare the stack so that ml_thread_switch_user can jump to usermode
 * with the specified IP/user SP */
extern kern_status_t ml_thread_prepare_user_context(
	virt_addr_t ip,
	virt_addr_t user_sp,
	virt_addr_t *kernel_sp,
	const uintptr_t *args,
	size_t nr_args);

#endif