NetBSD/sys/sys/sa.h
cl e7045955c7 kernel part of no-syscall upcall stack return: libpthread registers
an offset between ss_sp and struct sa_stackinfo_t (located in struct
__pthread_st) when calling sa_register.  The kernel increments the
sast_gen counter in struct sastack when an upcall stack is used.
libpthread increments the sasi_stackgen counter in struct
sa_stackinfo_t when an upcall stack is freed.  The kernel compares the
two counters to decide if a stack is free or in use.

- add struct sa_stackinfo_t with sasi_stackgen to count stack use in
  userland
- add sast_gen to struct sastack to count stack use in kernel
- add SA_FLAG_STACKINFO to enable the stackinfo_offset argument in the
  sa_register syscall
- add sa_stackinfo_offset to struct sadata for offset between ss_sp
  and struct sa_stackinfo_t
- add ssize_t stackinfo_offset argument to sa_register, initialize
  struct sadata's sa_stackinfo_offset from it if SA_FLAG_STACKINFO is
  set
- add sa_getstack, sa_getstack0, sa_stackused and sa_setstackfree
  functions to find/use/free upcall stacks and use these where
  appropriate
- don't record stack for upcall in sa_upcall0
- pass sau to sa_switchcall instead of l2 (l2 = curlwp in sa_switchcall)
- add sa_vp_blocker to struct sadata to pass recently blocked lwp to
  sa_switchcall
- delay finding a stack for blocked upcalls to sa_switchcall
- add sa_stacknext to struct sadata pointing to next most likely free
  upcall stack; also g/c sa_stackslist in struct sadata and sast_list
  in struct sastack
- add L_SA_WOKEN flag: LWP is on sa_woken queue
- add L_SA_RECYCLE flag: LWP should be recycled in sa_setwoken
- replace l_upcallstack with L_SA_WOKEN/L_SA_RECYCLE/L_SA_BLOCKING
  flags
- g/c now unused sast_blocker in struct sastack
- make sa_switchcall, sa_upcall0 and sa_upcall_getstate static in
  kern_sa.c
- call sa_upcall_userret only once in userret
- split sa_makeupcalls out of sa_upcall_userret and use to process
  the sa_upcalls queue
- on process exit: mark LWPs sleeping in saunblock interruptible; also
  there are no LWPs sleeping on l->l_upcallstack anymore; also clear
  sa_wokenq_head to prevent unblocked upcalls

additional changes:
- cleanup timerupcall sa_vp == curlwp check
- add check in sa_yield if we didn't block on our way here and we
  wouldn't any longer be the LWP on the VP
- invalidate sa_vp_ofaultaddr after resolving pagefault
2004-01-02 18:52:17 +00:00

71 lines
2.7 KiB
C

/* $NetBSD: sa.h,v 1.4 2004/01/02 18:52:17 cl Exp $ */
/*-
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Nathan J. Williams.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
#ifndef _SYS_SA_H
#define _SYS_SA_H
#include <sys/ucontext.h>
struct sa_t {
ucontext_t *sa_context;
int sa_id;
int sa_cpu;
};
/* kernel known per upcall stack data */
struct sa_stackinfo_t {
__volatile unsigned int sasi_stackgen; /* stack generation counter */
};
typedef void (*sa_upcall_t)(int, struct sa_t *[], int, int, void *);
#define SA_UPCALL_NEWPROC 0
#define SA_UPCALL_PREEMPTED 1
#define SA_UPCALL_BLOCKED 2
#define SA_UPCALL_UNBLOCKED 3
#define SA_UPCALL_SIGNAL 4
#define SA_UPCALL_SIGEV 5
#define SA_UPCALL_USER 6
#define SA_UPCALL_NUPCALLS 7
#define SA_FLAG_PREEMPT 0x0001 /* Generate upcalls on a vanilla preempt() */
#define SA_FLAG_STACKINFO 0x010000 /* Use stackinfo for upcall stack return */
#endif /* !_SYS_SA_H */