a2622e5dc2
return path only when neither thread was context switched while executing syscall code nor syscall explicitely modified LDT or MSRs. Save segment registers in trap handlers before interrupts are enabled, to not allow context switches to happen before registers are saved. Use separated byte in pcb for indication of fast/full return, since pcb_flags are not synchronized with context switches. The change puts back syscall microbenchmark numbers that were slowed down after commit of the support for LDT on amd64. Reviewed by: jeff Tested (and tested, and tested ...) by: pho Approved by: re (kensmith)
105 lines
3.2 KiB
C
105 lines
3.2 KiB
C
/*-
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* Copyright (c) 2003 Peter Wemm.
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* Copyright (c) 1990 The Regents of the University of California.
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* All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* William Jolitz.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* from: @(#)pcb.h 5.10 (Berkeley) 5/12/91
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* $FreeBSD$
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*/
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#ifndef _AMD64_PCB_H_
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#define _AMD64_PCB_H_
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/*
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* AMD64 process control block
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*/
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#include <machine/fpu.h>
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#include <machine/segments.h>
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struct pcb {
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register_t pcb_cr3;
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register_t pcb_r15;
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register_t pcb_r14;
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register_t pcb_r13;
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register_t pcb_r12;
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register_t pcb_rbp;
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register_t pcb_rsp;
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register_t pcb_rbx;
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register_t pcb_rip;
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register_t pcb_fsbase;
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register_t pcb_gsbase;
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u_long pcb_flags;
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#define PCB_DBREGS 0x02 /* process using debug registers */
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#define PCB_FPUINITDONE 0x08 /* fpu state is initialized */
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#define PCB_GS32BIT 0x20 /* linux gs switch */
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#define PCB_32BIT 0x40 /* process has 32 bit context (segs etc) */
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#define PCB_FULLCTX 0x80 /* full context restore on sysret */
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u_int64_t pcb_dr0;
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u_int64_t pcb_dr1;
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u_int64_t pcb_dr2;
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u_int64_t pcb_dr3;
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u_int64_t pcb_dr6;
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u_int64_t pcb_dr7;
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struct savefpu pcb_save;
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uint16_t pcb_initial_fpucw;
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caddr_t pcb_onfault; /* copyin/out fault recovery */
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/* 32-bit segment descriptor */
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struct user_segment_descriptor pcb_gs32sd;
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/* local tss, with i/o bitmap; NULL for common */
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struct amd64tss *pcb_tssp;
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char pcb_full_iret;
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};
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struct xpcb {
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struct pcb xpcb_pcb;
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register_t xpcb_cr0;
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register_t xpcb_cr2;
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register_t xpcb_cr4;
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register_t xpcb_kgsbase;
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struct region_descriptor xpcb_gdt;
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struct region_descriptor xpcb_idt;
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struct region_descriptor xpcb_ldt;
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uint16_t xpcb_tr;
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};
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#ifdef _KERNEL
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struct trapframe;
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void makectx(struct trapframe *, struct pcb *);
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void savectx(struct pcb *);
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int savectx2(struct xpcb *);
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#endif
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#endif /* _AMD64_PCB_H_ */
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