coreboot-kgpe-d16/src/include/thread.h

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/* SPDX-License-Identifier: GPL-2.0-only */
#ifndef THREAD_H_
#define THREAD_H_
#include <arch/cpu.h>
#include <bootstate.h>
#include <types.h>
struct thread_mutex {
bool locked;
};
enum thread_state {
THREAD_UNINITIALIZED,
THREAD_STARTED,
THREAD_DONE,
};
struct thread_handle {
enum thread_state state;
/* Only valid when state == THREAD_DONE */
enum cb_err error;
};
/* Run func(arg) on a new thread. Return 0 on successful start of thread, < 0
* when thread could not be started. The thread handle if populated, will
* reflect the state and return code of the thread.
*/
int thread_run(struct thread_handle *handle, enum cb_err (*func)(void *), void *arg);
/* thread_run_until is the same as thread_run() except that it blocks state
* transitions from occurring in the (state, seq) pair of the boot state
* machine. */
int thread_run_until(struct thread_handle *handle, enum cb_err (*func)(void *), void *arg,
boot_state_t state, boot_state_sequence_t seq);
/* Waits until the thread has terminated and returns the error code */
enum cb_err thread_join(struct thread_handle *handle);
#if ENV_STAGE_SUPPORTS_COOP
struct thread {
int id;
uintptr_t stack_current;
uintptr_t stack_orig;
struct thread *next;
enum cb_err (*entry)(void *);
void *entry_arg;
int can_yield;
struct thread_handle *handle;
};
/* Return 0 on successful yield, < 0 when thread did not yield. */
int thread_yield(void);
/* Return 0 on successful yield for the given amount of time, < 0 when thread
* did not yield. */
int thread_yield_microseconds(unsigned int microsecs);
/* Allow and prevent thread cooperation on current running thread. By default
* all threads are marked to be cooperative. That means a thread can yield
* to another thread at a pre-determined switch point. i.e., udelay,
* thread_yield, or thread_yield_microseconds.
*
* These methods should be used to guard critical sections so a dead lock does
* not occur. The critical sections can be nested. Just make sure the methods
* are used in pairs.
*/
void thread_coop_enable(void);
void thread_coop_disable(void);
void thread_mutex_lock(struct thread_mutex *mutex);
void thread_mutex_unlock(struct thread_mutex *mutex);
/* Architecture specific thread functions. */
asmlinkage void switch_to_thread(uintptr_t new_stack, uintptr_t *saved_stack);
/* Set up the stack frame for a new thread so that a switch_to_thread() call
* will enter the thread_entry() function with arg as a parameter. The
* saved_stack field in the struct thread needs to be updated accordingly. */
void arch_prepare_thread(struct thread *t,
asmlinkage void (*thread_entry)(void *), void *arg);
#else
static inline int thread_yield(void)
{
return -1;
}
static inline int thread_yield_microseconds(unsigned int microsecs)
{
return -1;
}
static inline void thread_coop_enable(void) {}
static inline void thread_coop_disable(void) {}
static inline void thread_mutex_lock(struct thread_mutex *mutex) {}
static inline void thread_mutex_unlock(struct thread_mutex *mutex) {}
#endif
#endif /* THREAD_H_ */