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      1 /*	$NetBSD: pcb.h,v 1.16 2009/10/13 22:41:57 pooka 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_ */
    195