src/include/thread.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2 #ifndef THREAD_H_
   3 #define THREAD_H_
   4
   5 #include <stdint.h>
   6 #include <bootstate.h>
   7 #include <arch/cpu.h>
   8
   9 #if ENV_RAMSTAGE && CONFIG(COOP_MULTITASKING)
  10
  11 struct thread {
  12         int id;
  13         uintptr_t stack_current;
  14         uintptr_t stack_orig;
  15         struct thread *next;
  16         void (*entry)(void *);
  17         void *entry_arg;
  18         int can_yield;
  19 };
  20
  21 void threads_initialize(void);
  22 /* Get the base of the thread stacks.
  23  * Returns pointer to CONFIG_NUM_THREADS*CONFIG_STACK_SIZE contiguous bytes
  24  * aligned to CONFIG_STACK_SIZE, or NULL.
  25  */
  26 void *arch_get_thread_stackbase(void);
  27 /* Run func(arrg) on a new thread. Return 0 on successful start of thread, < 0
  28  * when thread could not be started. Note that the thread will block the
  29  * current state in the boot state machine until it is complete. */
  30 int thread_run(void (*func)(void *), void *arg);
  31 /* thread_run_until is the same as thread_run() except that it blocks state
  32  * transitions from occurring in the (state, seq) pair of the boot state
  33  * machine. */
  34 int thread_run_until(void (*func)(void *), void *arg,
  35                      boot_state_t state, boot_state_sequence_t seq);
  36 /* Return 0 on successful yield for the given amount of time, < 0 when thread
  37  * did not yield. */
  38 int thread_yield_microseconds(unsigned int microsecs);
  39
  40 /* Allow and prevent thread cooperation on current running thread. By default
  41  * all threads are marked to be cooperative. That means a thread can yield
  42  * to another thread at a pre-determined switch point. Current there is
  43  * only a single place where switching may occur: a call to udelay(). */
  44 void thread_cooperate(void);
  45 void thread_prevent_coop(void);
  46
  47 static inline void thread_init_cpu_info_non_bsp(struct cpu_info *ci)
  48 {
  49         ci->thread = NULL;
  50 }
  51
  52 /* Architecture specific thread functions. */
  53 asmlinkage void switch_to_thread(uintptr_t new_stack, uintptr_t *saved_stack);
  54 /* Set up the stack frame for a new thread so that a switch_to_thread() call
  55  * will enter the thread_entry() function with arg as a parameter. The
  56  * saved_stack field in the struct thread needs to be updated accordingly. */
  57 void arch_prepare_thread(struct thread *t,
  58                          asmlinkage void (*thread_entry)(void *), void *arg);
  59 #else
  60 static inline void threads_initialize(void) {}
  61 static inline int thread_run(void (*func)(void *), void *arg) { return -1; }
  62 static inline int thread_yield_microseconds(unsigned int microsecs)
  63 {
  64         return -1;
  65 }
  66 static inline void thread_cooperate(void) {}
  67 static inline void thread_prevent_coop(void) {}
  68 struct cpu_info;
  69 static inline void thread_init_cpu_info_non_bsp(struct cpu_info *ci) { }
  70 #endif
  71
  72 #endif /* THREAD_H_ */