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* Initialise pcb_pmap for new threads.

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* Add support for forking new threads from &thread0 as well as curthread.
This commit is contained in:
Doug Rabson 2002-03-14 19:34:50 +00:00
parent 92e814dcb6
commit 34da0be411
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=92286
1 changed files with 40 additions and 21 deletions
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61
sys/ia64/ia64/vm_machdep.c
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@ -134,6 +134,9 @@ cpu_fork(td1, p2, td2, flags)
struct trapframe *p2tf;
u_int64_t bspstore, *p1bs, *p2bs, rnatloc, rnat;
KASSERT(td1 == curthread || td1 == &thread0,
("cpu_fork: p1 not curproc and not proc0"));
if ((flags & RFPROC) == 0)
return;
@ -174,9 +177,8 @@ cpu_fork(td1, p2, td2, flags)
* is started, to resume here, returning nonzero from setjmp.
*/
#ifdef DIAGNOSTIC
if (td1 != curthread)
panic("cpu_fork: curproc");
ia64_fpstate_check(td1);
if (td1 == curthread)
ia64_fpstate_check(td1);
#endif
/*
@ -184,10 +186,13 @@ cpu_fork(td1, p2, td2, flags)
*
* Pick a stack pointer, leaving room for a trapframe;
* copy trapframe from parent so return to user mode
* will be to right address, with correct registers.
* will be to right address, with correct registers. Clear the
* high-fp enable for the new process so that it is forced to
* load its state from the pcb.
*/
td2->td_frame = (struct trapframe *)td2->td_pcb - 1;
bcopy(td1->td_frame, td2->td_frame, sizeof(struct trapframe));
td2->td_frame->tf_cr_ipsr |= IA64_PSR_DFH;
/*
* Set up return-value registers as fork() libc stub expects.
@ -205,15 +210,21 @@ cpu_fork(td1, p2, td2, flags)
*
* We could cope with td1!=curthread by digging values
* out of its PCB but I don't see the point since
* current usage never allows it.
* current usage only allows &thread0 when creating kernel
* threads and &thread0 doesn't have any dirty regs.
*/
__asm __volatile("mov ar.rsc=0;;");
__asm __volatile("flushrs;;" ::: "memory");
__asm __volatile("mov %0=ar.bspstore" : "=r"(bspstore));
p1bs = (u_int64_t *)td1->td_kstack;
p2bs = (u_int64_t *)td2->td_kstack;
if (td1 == curthread) {
__asm __volatile("mov ar.rsc=0;;");
__asm __volatile("flushrs;;" ::: "memory");
__asm __volatile("mov %0=ar.bspstore" : "=r"(bspstore));
} else {
bspstore = (u_int64_t) p1bs;
}
/*
* Copy enough of td1's backing store to include all
* the user's stacked regs.
@ -225,29 +236,37 @@ cpu_fork(td1, p2, td2, flags)
* where the last ar.rnat which covers the user's
* saved registers would be placed. If so, we read
* that one from memory, otherwise we take td1's
* current ar.rnat.
* current ar.rnat. If we are simply spawning a new kthread
* from &thread0 we don't care about ar.rnat.
*/
rnatloc = (u_int64_t)p1bs + td1->td_frame->tf_ndirty;
rnatloc |= 0x1f8;
if (bspstore > rnatloc)
rnat = *(u_int64_t *) rnatloc;
else
__asm __volatile("mov %0=ar.rnat;;" : "=r"(rnat));
/*
* Switch the RSE back on.
*/
__asm __volatile("mov ar.rsc=3;;");
if (td1 == curthread) {
rnatloc = (u_int64_t)p1bs + td1->td_frame->tf_ndirty;
rnatloc |= 0x1f8;
if (bspstore > rnatloc)
rnat = *(u_int64_t *) rnatloc;
else
__asm __volatile("mov %0=ar.rnat;;" : "=r"(rnat));
/*
* Switch the RSE back on.
*/
__asm __volatile("mov ar.rsc=3;;");
} else {
rnat = 0;
}
/*
* Setup the child's pcb so that its ar.bspstore
* starts just above the region which we copied. This
* should work since the child will normally return
* straight into exception_restore.
* straight into exception_restore. Also initialise its
* pmap to the containing proc's vmspace.
*/
td2->td_pcb->pcb_bspstore = (u_int64_t)p2bs + td1->td_frame->tf_ndirty;
td2->td_pcb->pcb_rnat = rnat;
td2->td_pcb->pcb_pfs = 0;
td2->td_pcb->pcb_pmap = (u_int64_t)
vmspace_pmap(td2->td_proc->p_vmspace);
/*
* Arrange for continuation at fork_return(), which