Annotation of sys/arch/sparc64/include/pcb.h, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: pcb.h,v 1.7 2007/05/26 00:36:03 krw Exp $ */
! 2: /* $NetBSD: pcb.h,v 1.7 2000/12/29 17:12:05 eeh Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1992, 1993
! 6: * The Regents of the University of California. All rights reserved.
! 7: *
! 8: * This software was developed by the Computer Systems Engineering group
! 9: * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
! 10: * contributed to Berkeley.
! 11: *
! 12: * All advertising materials mentioning features or use of this software
! 13: * must display the following acknowledgement:
! 14: * This product includes software developed by the University of
! 15: * California, Lawrence Berkeley Laboratory.
! 16: *
! 17: * Redistribution and use in source and binary forms, with or without
! 18: * modification, are permitted provided that the following conditions
! 19: * are met:
! 20: * 1. Redistributions of source code must retain the above copyright
! 21: * notice, this list of conditions and the following disclaimer.
! 22: * 2. Redistributions in binary form must reproduce the above copyright
! 23: * notice, this list of conditions and the following disclaimer in the
! 24: * documentation and/or other materials provided with the distribution.
! 25: * 3. Neither the name of the University nor the names of its contributors
! 26: * may be used to endorse or promote products derived from this software
! 27: * without specific prior written permission.
! 28: *
! 29: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 30: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 31: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 32: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 33: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 34: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 35: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 36: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 37: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 38: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 39: * SUCH DAMAGE.
! 40: *
! 41: * @(#)pcb.h 8.1 (Berkeley) 6/11/93
! 42: */
! 43:
! 44: #ifndef _SPARC64_PCB_H_
! 45: #define _SPARC64_PCB_H_
! 46:
! 47: #include <machine/reg.h>
! 48:
! 49: #ifdef notyet
! 50: #define PCB_MAXWIN 32 /* architectural limit */
! 51: #else
! 52: #define PCB_MAXWIN 8 /* worried about u area sizes ... */
! 53: #endif
! 54:
! 55: /*
! 56: * SPARC Process Control Block.
! 57: *
! 58: * pcb_uw is positive if there are any user windows that are
! 59: * are currently in the CPU windows rather than on the user
! 60: * stack. Whenever we are running in the kernel with traps
! 61: * enabled, we decrement pcb_uw for each ``push'' of a CPU
! 62: * register window into the stack, and we increment it for
! 63: * each ``pull'' from the stack into the CPU. (If traps are
! 64: * disabled, or if we are in user mode, pcb_uw is junk.)
! 65: *
! 66: * To ease computing pcb_uw on traps from user mode, we keep track
! 67: * of the log base 2 of the single bit that is set in %wim.
! 68: *
! 69: * If an overflow occurs while the associated user stack pages
! 70: * are invalid (paged out), we have to store the registers
! 71: * in a page that is locked in core while the process runs,
! 72: * i.e., right here in the pcb. We also need the stack pointer
! 73: * for the last such window (but only the last, as the others
! 74: * are in each window) and the count of windows saved. We
! 75: * cheat by having a whole window structure for that one %sp.
! 76: * Thus, to save window pcb_rw[i] to memory, we write it at
! 77: * pcb_rw[i + 1].rw_in[6].
! 78: *
! 79: * pcb_nsaved has three `kinds' of values. If 0, it means no
! 80: * registers are in the PCB (though if pcb_uw is positive,
! 81: * there may be the next time you look). If positive, it means
! 82: * there are no user registers in the CPU, but there are some
! 83: * saved in pcb_rw[]. As a special case, traps that needed
! 84: * assistance to pull user registers from the stack also store
! 85: * the registers in pcb_rw[], and set pcb_nsaved to -1. This
! 86: * special state is normally short-term: it can only last until the
! 87: * trap returns, and it can never persist across entry to user code.
! 88: */
! 89: /*
! 90: * v9 addendum:
! 91: *
! 92: * Window handling between v8 and v9 has changed somewhat. There
! 93: * is no %wim. Instead, we have a %cwp, %cansave, %canrestore,
! 94: * %cleanwin, and %otherwin. By definition:
! 95: *
! 96: * %cansave + %canrestore + %otherwin = NWINDOWS - 2
! 97: *
! 98: * In addition, %cleanwin >= %canrestore since restorable windows
! 99: * are considered clean. This means that by storing %canrestore
! 100: * and %otherwin, we should be able to compute the values of all
! 101: * the other registers.
! 102: *
! 103: * The only other register we need to save is %cwp because it cannot
! 104: * be trivially computed from the other registers. The %cwp is
! 105: * stored in the %tstate register, but if the machine was in a register
! 106: * window spill/fill handler, the value of that %cwp may be off by
! 107: * as much as 2 register windows. We will also store %cwp. [We will
! 108: * try to steal pcb_uw or pcb_nsaved for this purpose eventually.]
! 109: *
! 110: * To calculate what registers are in the pcb, start with pcb_cwp
! 111: * and proceed to (pcb_cwp - pcb_canrestore) % NWINDOWS. These should
! 112: * be saved to their appropriate register windows. The client routine
! 113: * (trap handler) is responsible for saving pcb_cwp + 1 [%o1-%o7] in
! 114: * the trap frame or on the stack.
! 115: *
! 116: *
! 117: * Even more addendum:
! 118: *
! 119: * With the new system for keeping track of register windows we don't
! 120: * care about anything other than pcb_uw which keeps track of how many
! 121: * full windows we have. As soon as a flush traps, we dump all user
! 122: * windows to the pcb, handle the fault, then restore all user windows.
! 123: *
! 124: * XXX we are using pcb_nsaved as the counter. pcb_uw is still a mask.
! 125: * change this as soon as the new scheme is debugged.
! 126: */
! 127: struct pcb {
! 128: u_int64_t pcb_sp; /* sp (%o6) when switch() was called */
! 129: u_int64_t pcb_pc; /* pc (%o7) when switch() was called */
! 130: caddr_t pcb_onfault; /* for copyin/out */
! 131: short pcb_pstate; /* %pstate when switch() was called -- may be useful if we support multiple memory models */
! 132: char pcb_nsaved; /* number of windows saved in pcb */
! 133:
! 134: /* The rest is probably not needed except for pcb_rw */
! 135: char pcb_cwp; /* %cwp when switch() was called */
! 136: char pcb_pil; /* %pil when switch() was called -- probably not needed */
! 137:
! 138: const char *lastcall; /* DEBUG -- name of last system call */
! 139: u_int64_t pcb_wcookie;
! 140:
! 141: /* the following MUST be aligned on a 64-bit boundary */
! 142: struct rwindow64 pcb_rw[PCB_MAXWIN]; /* saved windows */
! 143: };
! 144:
! 145: /*
! 146: * The pcb is augmented with machine-dependent additional data for
! 147: * core dumps. Note that the trapframe here is a copy of the one
! 148: * from the top of the kernel stack (included here so that the kernel
! 149: * stack itself need not be dumped).
! 150: */
! 151: struct md_coredump {
! 152: struct trapframe64 md_tf;
! 153: struct fpstate64 md_fpstate;
! 154: u_int64_t md_wcookie;
! 155: };
! 156:
! 157: #ifndef _KERNEL
! 158: /* Let gdb compile. We need fancier macros to make these make sense. */
! 159: #define pcb_psr pcb_pstate
! 160: #define pcb_wim pcb_cwp
! 161: #endif /* _KERNEL */
! 162:
! 163: #endif /* _SPARC64_PCB_H_ */
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