sys/arch/sparc64/include/pcb.h

   1 /*      $NetBSD: pcb.h,v 1.15 2007/03/04 06:00:49 christos Exp $ */
   2
   3 /*
   4  * Copyright (c) 1992, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * This software was developed by the Computer Systems Engineering group
   8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
   9  * contributed to Berkeley.
  10  *
  11  * All advertising materials mentioning features or use of this software
  12  * must display the following acknowledgement:
  13  *      This product includes software developed by the University of
  14  *      California, Lawrence Berkeley Laboratory.
  15  *
  16  * Redistribution and use in source and binary forms, with or without
  17  * modification, are permitted provided that the following conditions
  18  * are met:
  19  * 1. Redistributions of source code must retain the above copyright
  20  *    notice, this list of conditions and the following disclaimer.
  21  * 2. Redistributions in binary form must reproduce the above copyright
  22  *    notice, this list of conditions and the following disclaimer in the
  23  *    documentation and/or other materials provided with the distribution.
  24  * 3. Neither the name of the University nor the names of its contributors
  25  *    may be used to endorse or promote products derived from this software
  26  *    without specific prior written permission.
  27  *
  28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  38  * SUCH DAMAGE.
  39  *
  40  *      @(#)pcb.h       8.1 (Berkeley) 6/11/93
  41  */
  42
  43 /*
  44  * Copyright (c) 1996-2002 Eduardo Horvath.  All rights reserved.
  45  *
  46  * Redistribution and use in source and binary forms, with or without
  47  * modification, are permitted provided that the following conditions
  48  * are met:
  49  * 1. Redistributions of source code must retain the above copyright
  50  *    notice, this list of conditions and the following disclaimer.
  51  * 2. Redistributions in binary form must reproduce the above copyright
  52  *    notice, this list of conditions and the following disclaimer in the
  53  *    documentation and/or other materials provided with the distribution.
  54  * 3. Neither the name of the author nor the names of its contributors
  55  *    may be used to endorse or promote products derived from this software
  56  *    without specific prior written permission.
  57  *
  58  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  68  * SUCH DAMAGE.
  69  *
  70  *      @(#)pcb.h       8.1 (Berkeley) 6/11/93
  71  */
  72
  73 #ifndef _SPARC64_PCB_H_
  74 #define _SPARC64_PCB_H_
  75
  76 #include <machine/reg.h>
  77
  78 #ifdef notyet
  79 #define PCB_MAXWIN      32      /* architectural limit */
  80 #else
  81 #define PCB_MAXWIN      8       /* worried about u area sizes ... */
  82 #endif
  83
  84 /*
  85  * SPARC Process Control Block.
  86  *
  87  * pcb_uw is positive if there are any user windows that are
  88  * are currently in the CPU windows rather than on the user
  89  * stack.  Whenever we are running in the kernel with traps
  90  * enabled, we decrement pcb_uw for each ``push'' of a CPU
  91  * register window into the stack, and we increment it for
  92  * each ``pull'' from the stack into the CPU.  (If traps are
  93  * disabled, or if we are in user mode, pcb_uw is junk.)
  94  *
  95  * To ease computing pcb_uw on traps from user mode, we keep track
  96  * of the log base 2 of the single bit that is set in %wim.
  97  *
  98  * If an overflow occurs while the associated user stack pages
  99  * are invalid (paged out), we have to store the registers
 100  * in a page that is locked in core while the process runs,
 101  * i.e., right here in the pcb.  We also need the stack pointer
 102  * for the last such window (but only the last, as the others
 103  * are in each window) and the count of windows saved.  We
 104  * cheat by having a whole window structure for that one %sp.
 105  * Thus, to save window pcb_rw[i] to memory, we write it at
 106  * pcb_rw[i + 1].rw_in[6].
 107  *
 108  * pcb_nsaved has three `kinds' of values.  If 0, it means no
 109  * registers are in the PCB (though if pcb_uw is positive,
 110  * there may be the next time you look).  If positive, it means
 111  * there are no user registers in the CPU, but there are some
 112  * saved in pcb_rw[].  As a special case, traps that needed
 113  * assistance to pull user registers from the stack also store
 114  * the registers in pcb_rw[], and set pcb_nsaved to -1.  This
 115  * special state is normally short-term: it can only last until the
 116  * trap returns, and it can never persist across entry to user code.
 117  */
 118 /*
 119  * v9 addendum:
 120  *
 121  * Window handling between v8 and v9 has changed somewhat.  There
 122  * is no %wim.  Instead, we have a %cwp, %cansave, %canrestore,
 123  * %cleanwin, and %otherwin.  By definition:
 124  *
 125  *       %cansave + %canrestore + %otherwin = NWINDOWS - 2
 126  *
 127  * In addition, %cleanwin >= %canrestore since restorable windows
 128  * are considered clean.  This means that by storing %canrestore
 129  * and %otherwin, we should be able to compute the values of all
 130  * the other registers.
 131  *
 132  * The only other register we need to save is %cwp because it cannot
 133  * be trivially computed from the other registers.  The %cwp is
 134  * stored in the %tstate register, but if the machine was in a register
 135  * window spill/fill handler, the value of that %cwp may be off by
 136  * as much as 2 register windows.  We will also store %cwp.  [We will
 137  * try to steal pcb_uw or pcb_nsaved for this purpose eventually.]
 138  *
 139  * To calculate what registers are in the pcb, start with pcb_cwp
 140  * and proceed to (pcb_cwp - pcb_canrestore) % NWINDOWS.  These should
 141  * be saved to their appropriate register windows.  The client routine
 142  * (trap handler) is responsible for saving pcb_cwp + 1 [%o1-%o7] in
 143  * the trap frame or on the stack.
 144  *
 145  *
 146  * Even more addendum:
 147  *
 148  * With the new system for keeping track of register windows we don't
 149  * care about anything other than pcb_uw which keeps track of how many
 150  * full windows we have.  As soon as a flush traps, we dump all user
 151  * windows to the pcb, handle the fault, then restore all user windows.
 152  *
 153  * XXX we are using pcb_nsaved as the counter.  pcb_uw is still a mask.
 154  * change this as soon as the new scheme is debugged.
 155  */
 156 struct pcb {
 157         uint64_t        pcb_sp;         /* sp (%o6) when switch() was called */
 158         uint64_t        pcb_pc;         /* pc (%o7) when switch() was called */
 159         void *  pcb_onfault;    /* for copyin/out */
 160         short   pcb_pstate;     /* %pstate when switch() was called -- may be useful if we support multiple memory models */
 161         char    pcb_nsaved;     /* number of windows saved in pcb */
 162
 163         /* The rest is probably not needed except for pcb_rw */
 164         char    pcb_cwp;        /* %cwp when switch() was called */
 165         char    pcb_pil;        /* %pil when switch() was called -- prolly not needed */
 166
 167         const char *lastcall;   /* DEBUG -- name of last system call */
 168         /* the following MUST be aligned on a 64-bit boundary */
 169         struct  rwindow64 pcb_rw[PCB_MAXWIN];   /* saved windows */
 170 };
 171
 172 /*
 173  * The pcb is augmented with machine-dependent additional data for
 174  * core dumps.  Note that the trapframe here is a copy of the one
 175  * from the top of the kernel stack (included here so that the kernel
 176  * stack itself need not be dumped).
 177  */
 178 struct md_coredump32 {
 179         struct  trapframe32 md_tf;
 180         struct  fpstate32 md_fpstate;
 181 };
 182
 183 struct md_coredump {
 184         struct  trapframe64 md_tf;
 185         struct  fpstate64 md_fpstate;
 186 };
 187
 188 #ifndef _KERNEL
 189 /* Let gdb compile.  We need fancier macros to make these make sense. */
 190 #define pcb_psr pcb_pstate
 191 #define pcb_wim pcb_cwp
 192 #endif /* _KERNEL */
 193
 194 #endif /* _SPARC64_PCB_H_ */