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/*
* Constant definitions related to
* scheduling policy.
*/
#ifndef _LINUX_LITMUS_H_
#define _LINUX_LITMUS_H_
#include <litmus/debug_trace.h>
#ifdef CONFIG_RELEASE_MASTER
extern atomic_t release_master_cpu;
#endif
/* in_list - is a given list_head queued on some list?
*/
static inline int in_list(struct list_head* list)
{
return !( /* case 1: deleted */
(list->next == LIST_POISON1 &&
list->prev == LIST_POISON2)
||
/* case 2: initialized */
(list->next == list &&
list->prev == list)
);
}
#define NO_CPU 0xffffffff
void litmus_fork(struct task_struct *tsk);
void litmus_exec(void);
/* clean up real-time state of a task */
void exit_litmus(struct task_struct *dead_tsk);
long litmus_admit_task(struct task_struct *tsk);
void litmus_exit_task(struct task_struct *tsk);
#define is_realtime(t) ((t)->policy == SCHED_LITMUS)
#define rt_transition_pending(t) \
((t)->rt_param.transition_pending)
#define tsk_rt(t) (&(t)->rt_param)
/* Realtime utility macros */
#define get_rt_flags(t) (tsk_rt(t)->flags)
#define set_rt_flags(t,f) (tsk_rt(t)->flags=(f))
#define get_exec_cost(t) (tsk_rt(t)->task_params.exec_cost)
#define get_exec_time(t) (tsk_rt(t)->job_params.exec_time)
#define get_rt_period(t) (tsk_rt(t)->task_params.period)
#define get_rt_phase(t) (tsk_rt(t)->task_params.phase)
#define get_partition(t) (tsk_rt(t)->task_params.cpu)
#define get_deadline(t) (tsk_rt(t)->job_params.deadline)
#define get_release(t) (tsk_rt(t)->job_params.release)
#define get_class(t) (tsk_rt(t)->task_params.cls)
#define is_priority_boosted(t) (tsk_rt(t)->priority_boosted)
#define get_boost_start(t) (tsk_rt(t)->boost_start_time)
inline static int budget_exhausted(struct task_struct* t)
{
return get_exec_time(t) >= get_exec_cost(t);
}
inline static lt_t budget_remaining(struct task_struct* t)
{
if (!budget_exhausted(t))
return get_exec_cost(t) - get_exec_time(t);
else
/* avoid overflow */
return 0;
}
#define budget_enforced(t) (tsk_rt(t)->task_params.budget_policy != NO_ENFORCEMENT)
#define budget_precisely_enforced(t) (tsk_rt(t)->task_params.budget_policy \
== PRECISE_ENFORCEMENT)
#define is_hrt(t) \
(tsk_rt(t)->task_params.cls == RT_CLASS_HARD)
#define is_srt(t) \
(tsk_rt(t)->task_params.cls == RT_CLASS_SOFT)
#define is_be(t) \
(tsk_rt(t)->task_params.cls == RT_CLASS_BEST_EFFORT)
/* Our notion of time within LITMUS: kernel monotonic time. */
static inline lt_t litmus_clock(void)
{
return ktime_to_ns(ktime_get());
}
/* A macro to convert from nanoseconds to ktime_t. */
#define ns_to_ktime(t) ktime_add_ns(ktime_set(0, 0), t)
#define get_domain(t) (tsk_rt(t)->domain)
/* Honor the flag in the preempt_count variable that is set
* when scheduling is in progress.
*/
#define is_running(t) \
((t)->state == TASK_RUNNING || \
task_thread_info(t)->preempt_count & PREEMPT_ACTIVE)
#define is_blocked(t) \
(!is_running(t))
#define is_released(t, now) \
(lt_before_eq(get_release(t), now))
#define is_tardy(t, now) \
(lt_before_eq(tsk_rt(t)->job_params.deadline, now))
/* real-time comparison macros */
#define earlier_deadline(a, b) (lt_before(\
(a)->rt_param.job_params.deadline,\
(b)->rt_param.job_params.deadline))
#define earlier_release(a, b) (lt_before(\
(a)->rt_param.job_params.release,\
(b)->rt_param.job_params.release))
void preempt_if_preemptable(struct task_struct* t, int on_cpu);
#ifdef CONFIG_LITMUS_LOCKING
void srp_ceiling_block(void);
#else
#define srp_ceiling_block() /* nothing */
#endif
#define bheap2task(hn) ((struct task_struct*) hn->value)
#ifdef CONFIG_NP_SECTION
static inline int is_kernel_np(struct task_struct *t)
{
return tsk_rt(t)->kernel_np;
}
static inline int is_user_np(struct task_struct *t)
{
return tsk_rt(t)->ctrl_page ? tsk_rt(t)->ctrl_page->np_flag : 0;
}
static inline void request_exit_np(struct task_struct *t)
{
if (is_user_np(t)) {
/* Set the flag that tells user space to call
* into the kernel at the end of a critical section. */
if (likely(tsk_rt(t)->ctrl_page)) {
TRACE_TASK(t, "setting delayed_preemption flag\n");
tsk_rt(t)->ctrl_page->delayed_preemption = 1;
}
}
}
static inline void clear_exit_np(struct task_struct *t)
{
if (likely(tsk_rt(t)->ctrl_page))
tsk_rt(t)->ctrl_page->delayed_preemption = 0;
}
static inline void make_np(struct task_struct *t)
{
tsk_rt(t)->kernel_np++;
}
/* Caller should check if preemption is necessary when
* the function return 0.
*/
static inline int take_np(struct task_struct *t)
{
return --tsk_rt(t)->kernel_np;
}
#else
static inline int is_kernel_np(struct task_struct* t)
{
return 0;
}
static inline int is_user_np(struct task_struct* t)
{
return 0;
}
static inline void request_exit_np(struct task_struct *t)
{
/* request_exit_np() shouldn't be called if !CONFIG_NP_SECTION */
BUG();
}
static inline void clear_exit_np(struct task_struct* t)
{
}
#endif
static inline int is_np(struct task_struct *t)
{
#ifdef CONFIG_SCHED_DEBUG_TRACE
int kernel, user;
kernel = is_kernel_np(t);
user = is_user_np(t);
if (kernel || user)
TRACE_TASK(t, " is non-preemptive: kernel=%d user=%d\n",
kernel, user);
return kernel || user;
#else
return unlikely(is_kernel_np(t) || is_user_np(t));
#endif
}
static inline int is_present(struct task_struct* t)
{
return t && tsk_rt(t)->present;
}
/* make the unit explicit */
typedef unsigned long quanta_t;
enum round {
FLOOR,
CEIL
};
/* Tick period is used to convert ns-specified execution
* costs and periods into tick-based equivalents.
*/
extern ktime_t tick_period;
static inline quanta_t time2quanta(lt_t time, enum round round)
{
s64 quantum_length = ktime_to_ns(tick_period);
if (do_div(time, quantum_length) && round == CEIL)
time++;
return (quanta_t) time;
}
/* By how much is cpu staggered behind CPU 0? */
u64 cpu_stagger_offset(int cpu);
#endif
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