linux/arch/alpha/include/asm/thread_info.h
Peter Zijlstra 2a705ad65c sched/idle, alpha: Switch from TS_POLLING to TIF_POLLING_NRFLAG
Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that
both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word.
This will allow us, using fetch_or(), to both set NEED_RESCHED and
check for POLLING_NRFLAG in a single operation and avoid pointless
wakeups.

Changing from the non-atomic thread_info::status flags to the atomic
thread_info::flags shouldn't be a big issue since most polling state
changes were followed/preceded by a full memory barrier anyway.

Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Richard Henderson <rth@twiddle.net>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: 蔡正龙 <zhenglong.cai@cs2c.com.cn>
Cc: linux-alpha@vger.kernel.org
Link: http://lkml.kernel.org/n/tip-9tfzr196gs0n2afxv0ga8pc3@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-08 09:16:53 +02:00

149 lines
4.5 KiB
C

#ifndef _ALPHA_THREAD_INFO_H
#define _ALPHA_THREAD_INFO_H
#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <asm/processor.h>
#include <asm/types.h>
#include <asm/hwrpb.h>
#include <asm/sysinfo.h>
#endif
#ifndef __ASSEMBLY__
struct thread_info {
struct pcb_struct pcb; /* palcode state */
struct task_struct *task; /* main task structure */
unsigned int flags; /* low level flags */
unsigned int ieee_state; /* see fpu.h */
struct exec_domain *exec_domain; /* execution domain */
mm_segment_t addr_limit; /* thread address space */
unsigned cpu; /* current CPU */
int preempt_count; /* 0 => preemptable, <0 => BUG */
unsigned int status; /* thread-synchronous flags */
int bpt_nsaved;
unsigned long bpt_addr[2]; /* breakpoint handling */
unsigned int bpt_insn[2];
struct restart_block restart_block;
};
/*
* Macros/functions for gaining access to the thread information structure.
*/
#define INIT_THREAD_INFO(tsk) \
{ \
.task = &tsk, \
.exec_domain = &default_exec_domain, \
.addr_limit = KERNEL_DS, \
.preempt_count = INIT_PREEMPT_COUNT, \
.restart_block = { \
.fn = do_no_restart_syscall, \
}, \
}
#define init_thread_info (init_thread_union.thread_info)
#define init_stack (init_thread_union.stack)
/* How to get the thread information struct from C. */
register struct thread_info *__current_thread_info __asm__("$8");
#define current_thread_info() __current_thread_info
#endif /* __ASSEMBLY__ */
/* Thread information allocation. */
#define THREAD_SIZE_ORDER 1
#define THREAD_SIZE (2*PAGE_SIZE)
/*
* Thread information flags:
* - these are process state flags and used from assembly
* - pending work-to-be-done flags come first and must be assigned to be
* within bits 0 to 7 to fit in and immediate operand.
*
* TIF_SYSCALL_TRACE is known to be 0 via blbs.
*/
#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
#define TIF_NOTIFY_RESUME 1 /* callback before returning to user */
#define TIF_SIGPENDING 2 /* signal pending */
#define TIF_NEED_RESCHED 3 /* rescheduling necessary */
#define TIF_SYSCALL_AUDIT 4 /* syscall audit active */
#define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */
#define TIF_MEMDIE 13 /* is terminating due to OOM killer */
#define TIF_POLLING_NRFLAG 14 /* idle is polling for TIF_NEED_RESCHED */
#define _TIF_SYSCALL_TRACE (1<<TIF_SYSCALL_TRACE)
#define _TIF_SIGPENDING (1<<TIF_SIGPENDING)
#define _TIF_NEED_RESCHED (1<<TIF_NEED_RESCHED)
#define _TIF_NOTIFY_RESUME (1<<TIF_NOTIFY_RESUME)
#define _TIF_SYSCALL_AUDIT (1<<TIF_SYSCALL_AUDIT)
#define _TIF_POLLING_NRFLAG (1<<TIF_POLLING_NRFLAG)
/* Work to do on interrupt/exception return. */
#define _TIF_WORK_MASK (_TIF_SIGPENDING | _TIF_NEED_RESCHED | \
_TIF_NOTIFY_RESUME)
/* Work to do on any return to userspace. */
#define _TIF_ALLWORK_MASK (_TIF_WORK_MASK \
| _TIF_SYSCALL_TRACE)
#define TS_UAC_NOPRINT 0x0001 /* ! Preserve the following three */
#define TS_UAC_NOFIX 0x0002 /* ! flags as they match */
#define TS_UAC_SIGBUS 0x0004 /* ! userspace part of 'osf_sysinfo' */
#define TS_RESTORE_SIGMASK 0x0008 /* restore signal mask in do_signal() */
#ifndef __ASSEMBLY__
#define HAVE_SET_RESTORE_SIGMASK 1
static inline void set_restore_sigmask(void)
{
struct thread_info *ti = current_thread_info();
ti->status |= TS_RESTORE_SIGMASK;
WARN_ON(!test_bit(TIF_SIGPENDING, (unsigned long *)&ti->flags));
}
static inline void clear_restore_sigmask(void)
{
current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
}
static inline bool test_restore_sigmask(void)
{
return current_thread_info()->status & TS_RESTORE_SIGMASK;
}
static inline bool test_and_clear_restore_sigmask(void)
{
struct thread_info *ti = current_thread_info();
if (!(ti->status & TS_RESTORE_SIGMASK))
return false;
ti->status &= ~TS_RESTORE_SIGMASK;
return true;
}
#endif
#define SET_UNALIGN_CTL(task,value) ({ \
__u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \
if (value & PR_UNALIGN_NOPRINT) \
status |= TS_UAC_NOPRINT; \
if (value & PR_UNALIGN_SIGBUS) \
status |= TS_UAC_SIGBUS; \
if (value & 4) /* alpha-specific */ \
status |= TS_UAC_NOFIX; \
task_thread_info(task)->status = status; \
0; })
#define GET_UNALIGN_CTL(task,value) ({ \
__u32 status = task_thread_info(task)->status & ~UAC_BITMASK; \
__u32 res = 0; \
if (status & TS_UAC_NOPRINT) \
res |= PR_UNALIGN_NOPRINT; \
if (status & TS_UAC_SIGBUS) \
res |= PR_UNALIGN_SIGBUS; \
if (status & TS_UAC_NOFIX) \
res |= 4; \
put_user(res, (int __user *)(value)); \
})
#endif /* __KERNEL__ */
#endif /* _ALPHA_THREAD_INFO_H */