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#ifndef _LITMUS_CTRLPAGE_H_
#define _LITMUS_CTRLPAGE_H_
#include <litmus/rt_param.h>
union np_flag {
uint32_t raw;
struct {
/* Is the task currently in a non-preemptive section? */
uint32_t flag:31;
/* Should the task call into the scheduler? */
uint32_t preempt:1;
} np;
};
/* The definition of the data that is shared between the kernel and real-time
* tasks via a shared page (see litmus/ctrldev.c).
*
* WARNING: User space can write to this, so don't trust
* the correctness of the fields!
*
* This servees two purposes: to enable efficient signaling
* of non-preemptive sections (user->kernel) and
* delayed preemptions (kernel->user), and to export
* some real-time relevant statistics such as preemption and
* migration data to user space. We can't use a device to export
* statistics because we want to avoid system call overhead when
* determining preemption/migration overheads).
*/
struct control_page {
/* This flag is used by userspace to communicate non-preempive
* sections. */
volatile __attribute__ ((aligned (8))) union np_flag sched;
/* Incremented by the kernel each time an IRQ is handled. */
volatile __attribute__ ((aligned (8))) uint64_t irq_count;
/* Locking overhead tracing: userspace records here the time stamp
* and IRQ counter prior to starting the system call. */
uint64_t ts_syscall_start; /* Feather-Trace cycles */
uint64_t irq_syscall_start; /* Snapshot of irq_count when the syscall
* started. */
lt_t deadline; /* Deadline for the currently executing job */
lt_t release; /* Release time of current job */
uint64_t job_index; /* Job sequence number of current job */
/* to be extended */
};
/* Expected offsets within the control page. */
#define LITMUS_CP_OFFSET_SCHED 0
#define LITMUS_CP_OFFSET_IRQ_COUNT 8
#define LITMUS_CP_OFFSET_TS_SC_START 16
#define LITMUS_CP_OFFSET_IRQ_SC_START 24
#define LITMUS_CP_OFFSET_DEADLINE 32
#define LITMUS_CP_OFFSET_RELEASE 40
#define LITMUS_CP_OFFSET_JOB_INDEX 48
/* System call emulation via ioctl() */
typedef enum {
LRT_null_call = 2006,
LRT_set_rt_task_param,
LRT_get_rt_task_param,
LRT_reservation_create,
LRT_complete_job,
LRT_od_open,
LRT_od_close,
LRT_litmus_lock,
LRT_litmus_unlock,
LRT_wait_for_job_release,
LRT_wait_for_ts_release,
LRT_release_ts,
LRT_get_current_budget,
} litmus_syscall_id_t;
union litmus_syscall_args {
struct {
pid_t pid;
struct rt_task __user *param;
} get_set_task_param;
struct {
uint32_t type;
void __user *config;
} reservation_create;
struct {
uint32_t fd;
uint32_t obj_type;
uint32_t obj_id;
void __user *config;
} od_open;
struct {
lt_t __user *expended;
lt_t __user *remaining;
} get_current_budget;
};
#endif
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