FreeBSD/Linux Kernel Cross Reference
sys/amd64/include/pcb.h

     /*-
      * Copyright (c) 2003 Peter Wemm.
      * Copyright (c) 1990 The Regents of the University of California.
      * All rights reserved.
      *
      * This code is derived from software contributed to Berkeley by
      * William Jolitz.
      *
      * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     * 4. Neither the name of the University nor the names of its contributors
     *    may be used to endorse or promote products derived from this software
     *    without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     *      from: @(#)pcb.h 5.10 (Berkeley) 5/12/91
     * $FreeBSD: releng/9.0/sys/amd64/include/pcb.h 216673 2010-12-22 19:57:03Z jkim $
     */
    
    #ifndef _AMD64_PCB_H_
    #define _AMD64_PCB_H_
    
    /*
     * AMD64 process control block
     */
    #include <machine/fpu.h>
    #include <machine/segments.h>
    
    struct pcb {
            register_t      pcb_r15;
            register_t      pcb_r14;
            register_t      pcb_r13;
            register_t      pcb_r12;
            register_t      pcb_rbp;
            register_t      pcb_rsp;
            register_t      pcb_rbx;
            register_t      pcb_rip;
            register_t      pcb_fsbase;
            register_t      pcb_gsbase;
            register_t      pcb_kgsbase;
            register_t      pcb_cr0;
            register_t      pcb_cr2;
            register_t      pcb_cr3;
            register_t      pcb_cr4;
            register_t      pcb_dr0;
            register_t      pcb_dr1;
            register_t      pcb_dr2;
            register_t      pcb_dr3;
            register_t      pcb_dr6;
            register_t      pcb_dr7;
    
            struct region_descriptor pcb_gdt;
            struct region_descriptor pcb_idt;
            struct region_descriptor pcb_ldt;
            uint16_t        pcb_tr;
    
            u_int           pcb_flags;
    #define PCB_FULL_IRET   0x01    /* full iret is required */
    #define PCB_DBREGS      0x02    /* process using debug registers */
    #define PCB_KERNFPU     0x04    /* kernel uses fpu */
    #define PCB_FPUINITDONE 0x08    /* fpu state is initialized */
    #define PCB_USERFPUINITDONE 0x10 /* fpu user state is initialized */
    #define PCB_GS32BIT     0x20    /* linux gs switch */
    #define PCB_32BIT       0x40    /* process has 32 bit context (segs etc) */
    
            uint16_t        pcb_initial_fpucw;
    
            /* copyin/out fault recovery */
            caddr_t         pcb_onfault;
    
            /* 32-bit segment descriptor */
            struct user_segment_descriptor pcb_gs32sd;
    
            /* local tss, with i/o bitmap; NULL for common */
            struct amd64tss *pcb_tssp;
    
            struct savefpu  *pcb_save;
            struct savefpu  pcb_user_save;
    };
    
    #ifdef _KERNEL
    struct trapframe;
   
   /*
    * The pcb_flags is only modified by current thread, or by other threads
    * when current thread is stopped.  However, current thread may change it
    * from the interrupt context in cpu_switch(), or in the trap handler.
    * When we read-modify-write pcb_flags from C sources, compiler may generate
    * code that is not atomic regarding the interrupt handler.  If a trap or
    * interrupt happens and any flag is modified from the handler, it can be
    * clobbered with the cached value later.  Therefore, we implement setting
    * and clearing flags with single-instruction functions, which do not race
    * with possible modification of the flags from the trap or interrupt context,
    * because traps and interrupts are executed only on instruction boundary.
    */
   static __inline void
   set_pcb_flags(struct pcb *pcb, const u_int flags)
   {
   
           __asm __volatile("orl %1,%0"
               : "=m" (pcb->pcb_flags) : "ir" (flags), "m" (pcb->pcb_flags)
               : "cc");
   }
   
   static __inline void
   clear_pcb_flags(struct pcb *pcb, const u_int flags)
   {
   
           __asm __volatile("andl %1,%0"
               : "=m" (pcb->pcb_flags) : "ir" (~flags), "m" (pcb->pcb_flags)
               : "cc");
   }
   
   void    makectx(struct trapframe *, struct pcb *);
   int     savectx(struct pcb *);
   #endif
   
   #endif /* _AMD64_PCB_H_ */

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