61c4628b53
Split the FPU save area from the task struct. This allows easy migration of FPU context, and it's generally cleaner. It also allows the following two optimizations: 1) only allocate when the application actually uses FPU, so in the first lazy FPU trap. This could save memory for non-fpu using apps. Next patch does this lazy allocation. 2) allocate the right size for the actual cpu rather than 512 bytes always. Patches enabling xsave/xrstor support (coming shortly) will take advantage of this. Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
196 lines
6.1 KiB
C
196 lines
6.1 KiB
C
/* thread_info.h: i386 low-level thread information
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*
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* Copyright (C) 2002 David Howells (dhowells@redhat.com)
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* - Incorporating suggestions made by Linus Torvalds and Dave Miller
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*/
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#ifndef _ASM_THREAD_INFO_H
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#define _ASM_THREAD_INFO_H
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#ifdef __KERNEL__
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#include <linux/compiler.h>
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#include <asm/page.h>
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#ifndef __ASSEMBLY__
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#include <asm/processor.h>
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#endif
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/*
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* low level task data that entry.S needs immediate access to
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* - this struct should fit entirely inside of one cache line
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* - this struct shares the supervisor stack pages
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* - if the contents of this structure are changed,
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* the assembly constants must also be changed
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*/
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#ifndef __ASSEMBLY__
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struct thread_info {
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struct task_struct *task; /* main task structure */
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struct exec_domain *exec_domain; /* execution domain */
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unsigned long flags; /* low level flags */
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unsigned long status; /* thread-synchronous flags */
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__u32 cpu; /* current CPU */
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int preempt_count; /* 0 => preemptable,
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<0 => BUG */
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mm_segment_t addr_limit; /* thread address space:
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0-0xBFFFFFFF user-thread
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0-0xFFFFFFFF kernel-thread
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*/
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void *sysenter_return;
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struct restart_block restart_block;
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unsigned long previous_esp; /* ESP of the previous stack in
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case of nested (IRQ) stacks
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*/
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__u8 supervisor_stack[0];
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};
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#else /* !__ASSEMBLY__ */
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#include <asm/asm-offsets.h>
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#endif
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#define PREEMPT_ACTIVE 0x10000000
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#ifdef CONFIG_4KSTACKS
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#define THREAD_SIZE (4096)
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#else
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#define THREAD_SIZE (8192)
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#endif
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#define STACK_WARN (THREAD_SIZE/8)
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/*
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* macros/functions for gaining access to the thread information structure
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*
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* preempt_count needs to be 1 initially, until the scheduler is functional.
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*/
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#ifndef __ASSEMBLY__
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#define INIT_THREAD_INFO(tsk) \
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{ \
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.task = &tsk, \
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.exec_domain = &default_exec_domain, \
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.flags = 0, \
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.cpu = 0, \
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.preempt_count = 1, \
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.addr_limit = KERNEL_DS, \
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.restart_block = { \
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.fn = do_no_restart_syscall, \
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}, \
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}
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#define init_thread_info (init_thread_union.thread_info)
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#define init_stack (init_thread_union.stack)
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/* how to get the current stack pointer from C */
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register unsigned long current_stack_pointer asm("esp") __used;
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/* how to get the thread information struct from C */
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static inline struct thread_info *current_thread_info(void)
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{
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return (struct thread_info *)
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(current_stack_pointer & ~(THREAD_SIZE - 1));
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}
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/* thread information allocation */
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#ifdef CONFIG_DEBUG_STACK_USAGE
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#define alloc_thread_info(tsk) ((struct thread_info *) \
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__get_free_pages(GFP_KERNEL | __GFP_ZERO, get_order(THREAD_SIZE)))
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#else
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#define alloc_thread_info(tsk) ((struct thread_info *) \
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__get_free_pages(GFP_KERNEL, get_order(THREAD_SIZE)))
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#endif
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#else /* !__ASSEMBLY__ */
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/* how to get the thread information struct from ASM */
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#define GET_THREAD_INFO(reg) \
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movl $-THREAD_SIZE, reg; \
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andl %esp, reg
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/* use this one if reg already contains %esp */
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#define GET_THREAD_INFO_WITH_ESP(reg) \
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andl $-THREAD_SIZE, reg
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#endif
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/*
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* thread information flags
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* - these are process state flags that various
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* assembly files may need to access
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* - pending work-to-be-done flags are in LSW
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* - other flags in MSW
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*/
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#define TIF_SYSCALL_TRACE 0 /* syscall trace active */
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#define TIF_SIGPENDING 1 /* signal pending */
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#define TIF_NEED_RESCHED 2 /* rescheduling necessary */
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#define TIF_SINGLESTEP 3 /* restore singlestep on return to
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user mode */
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#define TIF_IRET 4 /* return with iret */
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#define TIF_SYSCALL_EMU 5 /* syscall emulation active */
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#define TIF_SYSCALL_AUDIT 6 /* syscall auditing active */
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#define TIF_SECCOMP 7 /* secure computing */
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#define TIF_RESTORE_SIGMASK 8 /* restore signal mask in do_signal() */
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#define TIF_HRTICK_RESCHED 9 /* reprogram hrtick timer */
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#define TIF_MEMDIE 16
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#define TIF_DEBUG 17 /* uses debug registers */
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#define TIF_IO_BITMAP 18 /* uses I/O bitmap */
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#define TIF_FREEZE 19 /* is freezing for suspend */
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#define TIF_NOTSC 20 /* TSC is not accessible in userland */
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#define TIF_FORCED_TF 21 /* true if TF in eflags artificially */
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#define TIF_DEBUGCTLMSR 22 /* uses thread_struct.debugctlmsr */
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#define TIF_DS_AREA_MSR 23 /* uses thread_struct.ds_area_msr */
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#define TIF_BTS_TRACE_TS 24 /* record scheduling event timestamps */
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#define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE)
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#define _TIF_SIGPENDING (1 << TIF_SIGPENDING)
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#define _TIF_NEED_RESCHED (1 << TIF_NEED_RESCHED)
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#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP)
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#define _TIF_IRET (1 << TIF_IRET)
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#define _TIF_SYSCALL_EMU (1 << TIF_SYSCALL_EMU)
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#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
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#define _TIF_SECCOMP (1 << TIF_SECCOMP)
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#define _TIF_RESTORE_SIGMASK (1 << TIF_RESTORE_SIGMASK)
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#define _TIF_HRTICK_RESCHED (1 << TIF_HRTICK_RESCHED)
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#define _TIF_DEBUG (1 << TIF_DEBUG)
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#define _TIF_IO_BITMAP (1 << TIF_IO_BITMAP)
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#define _TIF_FREEZE (1 << TIF_FREEZE)
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#define _TIF_NOTSC (1 << TIF_NOTSC)
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#define _TIF_FORCED_TF (1 << TIF_FORCED_TF)
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#define _TIF_DEBUGCTLMSR (1 << TIF_DEBUGCTLMSR)
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#define _TIF_DS_AREA_MSR (1 << TIF_DS_AREA_MSR)
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#define _TIF_BTS_TRACE_TS (1 << TIF_BTS_TRACE_TS)
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/* work to do on interrupt/exception return */
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#define _TIF_WORK_MASK \
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(0x0000FFFF & ~(_TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT | \
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_TIF_SECCOMP | _TIF_SYSCALL_EMU))
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/* work to do on any return to u-space */
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#define _TIF_ALLWORK_MASK (0x0000FFFF & ~_TIF_SECCOMP)
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/* flags to check in __switch_to() */
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#define _TIF_WORK_CTXSW \
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(_TIF_IO_BITMAP | _TIF_NOTSC | _TIF_DEBUGCTLMSR | \
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_TIF_DS_AREA_MSR | _TIF_BTS_TRACE_TS)
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#define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
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#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW | _TIF_DEBUG)
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/*
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* Thread-synchronous status.
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*
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* This is different from the flags in that nobody else
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* ever touches our thread-synchronous status, so we don't
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* have to worry about atomic accesses.
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*/
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#define TS_USEDFPU 0x0001 /* FPU was used by this task
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this quantum (SMP) */
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#define TS_POLLING 0x0002 /* True if in idle loop
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and not sleeping */
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#define tsk_is_polling(t) (task_thread_info(t)->status & TS_POLLING)
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#endif /* __KERNEL__ */
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#endif /* _ASM_THREAD_INFO_H */
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