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/*
* Copyright (c) 1996, 1998, 1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit is distributed in the hope that it will be useful, but WITHOUT ANY
* WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Machine dependent thread initialization.
*/
#include <threads/pthread_internal.h>
#include <oskit/c/sys/mman.h>
#include <oskit/machine/trap.h>
#include <oskit/machine/base_trap.h>
#include <oskit/machine/proc_reg.h>
/*
* Pointer to fpustate for the thread that last used the FP unit. This
* points into a PCB structure, and starts out pointing at the main
* thread. At each context switch the TS flag is set. An attempt to
* use the FPU will cause an NM exception. The current state of the
* FPU will be saved into *cur_fpustate, cur_fpustate reset to point
* at the current thread PCB, and an FP reload done. The TS flag is
* cleared so that the FP operation can continue.
*/
pthread_thread_t *owner_fpu;
extern pthread_thread_t threads_mainthread;
extern int pthread_fpu_trap_handler(struct trap_state *ts);
extern int oskit_usermode_simulation;
extern void thread_switch_usermode(), thread_switch_realmode();
void (*thread_switch)(pthread_thread_t *pnext,
pthread_lock_t *l, pthread_thread_t *cur) = 0;
/*
* Machine dependent pthread system initialization.
*/
void
thread_machdep_init()
{
if (! oskit_usermode_simulation) {
#ifndef SMP
/*
* Override NM trap handler.
*/
base_trap_handlers[T_NO_FPU] = pthread_fpu_trap_handler;
owner_fpu = &threads_mainthread;
#endif
thread_switch = thread_switch_realmode;
}
else {
thread_switch = thread_switch_usermode;
}
}
/*
* Set up an initial stack that looks like:
*
* ------------
* | Pthread |
* ------------
* | Panic RA |
* ------------
* | Starter |
* ------------ <--- SP
*
* The starter routine takes the new pthread as its argument. It does
* some intitialization stuff, and then applies the user specified start
* function(argument). Set up a panic just in case something goes wrong
* and the threads unwinds too far.
*/
extern void pthread_start_thread(void);
extern void thread_fpuinit(oskit_u32_t *, oskit_u32_t *);
void
thread_setup(pthread_thread_t *pthread)
{
pcb_t *ppcb = pthread->ppcb;
oskit_u32_t *pframe;
void thread_bottom_exit();
oskit_u32_t fstate[32];
#ifdef STACKGUARD
if (pthread->guardsize)
pthread_mprotect((oskit_addr_t) pthread->pstk,
pthread->guardsize, PROT_READ);
#endif
/*
* The initial frame starts at the other end of the stack
* memory.
*/
pframe = (oskit_u32_t *) (((oskit_u32_t) pthread->pstk) +
pthread->ssize);
pframe -= 3;
pframe[0] = (oskit_u32_t) pthread_start_thread;
pframe[1] = (oskit_u32_t) thread_bottom_exit;
pframe[2] = (oskit_u32_t) pthread;
/*
* Setting the EIP would seem redundant, but the context switch
* code is going to use it instead of the location on the stack.
*/
ppcb->esp = (oskit_u32_t) pframe;
ppcb->eip = (oskit_u32_t) pthread_start_thread;
/*
* Set up the current floating point state. Done in asm code.
*/
thread_fpuinit(fstate, pthread->pcb.fstate);
}
/*
* Machine dependent thread destroy.
*/
void
thread_destroy(pthread_thread_t *pthread)
{
#ifdef STACKGUARD
if (pthread->guardsize)
pthread_mprotect((oskit_addr_t) pthread->pstk,
pthread->guardsize, PROT_READ|PROT_WRITE);
#endif
if (owner_fpu == pthread)
owner_fpu = &threads_mainthread;
}
void
thread_bottom_exit()
{
panic("thread_bottom_exit:");
}
/*
* Dump a stack backtrace for a switched out thread.
*/
int
threads_stack_back_trace(int tid, int max_st_levels)
{
unsigned int *fp, i;
pthread_thread_t *pthread;
if ((pthread = tidtothread((pthread_t) tid)) == NULL_THREADPTR)
return EINVAL;
if (pthread == CURPTHREAD())
return EINVAL;
fp = (unsigned int *) pthread->pcb.ebp;
printf("Backtrace tid:%d P:%08x: eip:0x%08x fp:0x%08x\n\t", tid,
(int) pthread, (int) pthread->pcb.eip, (int) fp);
for (i = 0; i < max_st_levels && fp != NULL; i++) {
if (!(*(fp + 1) && *fp))
break;
printf(" %08x", *(fp + 1));
fp = (int *)(*fp);
}
printf("\n");
return 0;
}
/*
* Get machine-specific thread state and stash into the given pointer.
* This is used by pthread_getstate.
*/
void
thread_getstate(pthread_thread_t *pthread, pthread_state_t *pstate)
{
pstate->stacksize = pthread->ssize - pthread->guardsize;
pstate->stackbase = (ssize_t)pthread->pstk + pthread->guardsize;
if (pthread == CURPTHREAD()) {
pstate->stackptr = (oskit_u32_t) get_esp();
pstate->frameptr = (oskit_u32_t) get_ebp();
}
else {
pstate->stackptr = (oskit_u32_t) pthread->pcb.esp;
pstate->frameptr = (oskit_u32_t) pthread->pcb.ebp;
}
}
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