freebsd-nq/sys/powerpc/aim/vm_machdep.c
Peter Grehan f86c114f3d Add the USER_SR segment register to pcb state. Initialize correctly,
and save/restore during a context switch.

The USER_SR could be overwritten when the current thread was switched
out with a faulting copyin/copyout.

Approved by: Benno
2002-10-21 05:27:41 +00:00

376 lines
9.1 KiB
C

/*-
* Copyright (c) 1982, 1986 The Regents of the University of California.
* Copyright (c) 1989, 1990 William Jolitz
* Copyright (c) 1994 John Dyson
* All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department, and William Jolitz.
*
* 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 University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*
* from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
* Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
* $FreeBSD$
*/
/*
* Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Chris G. Demetriou
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/fpu.h>
#include <machine/frame.h>
#include <machine/md_var.h>
#include <dev/ofw/openfirm.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_extern.h>
#include <sys/user.h>
/*
* quick version of vm_fault
*/
int
vm_fault_quick(v, prot)
caddr_t v;
int prot;
{
int r;
if (prot & VM_PROT_WRITE)
r = subyte(v, fubyte(v));
else
r = fubyte(v);
return(r);
}
/*
* Finish a fork operation, with process p2 nearly set up.
* Copy and update the pcb, set up the stack so that the child
* ready to run and return to user mode.
*/
void
cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
{
struct proc *p1;
struct trapframe *tf;
struct callframe *cf;
struct pcb *pcb;
KASSERT(td1 == curthread || td1 == &thread0,
("cpu_fork: p1 not curproc and not proc0"));
CTR3(KTR_PROC, "cpu_fork: called td1=%08x p2=%08x flags=%x", (u_int)td1, (u_int)p2, flags);
if ((flags & RFPROC) == 0)
return;
p1 = td1->td_proc;
pcb = (struct pcb *)((td2->td_kstack + KSTACK_PAGES * PAGE_SIZE -
sizeof(struct pcb)) & ~0x2fU);
td2->td_pcb = pcb;
/* Copy the pcb */
bcopy(td1->td_pcb, pcb, sizeof(struct pcb));
/*
* Create a fresh stack for the new process.
* Copy the trap frame for the return to user mode as if from a
* syscall. This copies most of the user mode register values.
*/
tf = (struct trapframe *)pcb - 1;
bcopy(td1->td_frame, tf, sizeof(*tf));
/* Set up trap frame. */
tf->fixreg[FIRSTARG] = 0;
tf->fixreg[FIRSTARG + 1] = 0;
tf->cr &= ~0x10000000;
td2->td_frame = tf;
cf = (struct callframe *)tf - 1;
cf->cf_func = (register_t)fork_return;
cf->cf_arg0 = (register_t)td2;
cf->cf_arg1 = (register_t)tf;
pcb->pcb_sp = (register_t)cf;
pcb->pcb_lr = (register_t)fork_trampoline;
pcb->pcb_usr = kernel_pmap->pm_sr[USER_SR];
/*
* Now cpu_switch() can schedule the new process.
*/
}
/*
* Intercept the return address from a freshly forked process that has NOT
* been scheduled yet.
*
* This is needed to make kernel threads stay in kernel mode.
*/
void
cpu_set_fork_handler(td, func, arg)
struct thread *td;
void (*func)(void *);
void *arg;
{
struct callframe *cf;
CTR3(KTR_PROC, "cpu_set_fork_handler: called with td=%08x func=%08x arg=%08x",
(u_int)td, (u_int)func, (u_int)arg);
cf = (struct callframe *)td->td_pcb->pcb_sp;
cf->cf_func = (register_t)func;
cf->cf_arg0 = (register_t)arg;
}
/*
* cpu_exit is called as the last action during exit.
* We release the address space of the process, block interrupts,
* and call switch_exit. switch_exit switches to proc0's PCB and stack,
* then jumps into the middle of cpu_switch, as if it were switching
* from proc0.
*/
void
cpu_exit(td)
register struct thread *td;
{
}
void
cpu_sched_exit(td)
register struct thread *td;
{
}
void
cpu_wait(td)
struct proc *td;
{
}
/* Temporary helper */
void
cpu_throw(void)
{
cpu_switch();
panic("cpu_throw() didn't");
}
/*
* Map an IO request into kernel virtual address space.
*
* All requests are (re)mapped into kernel VA space.
* Notice that we use b_bufsize for the size of the buffer
* to be mapped. b_bcount might be modified by the driver.
*/
void
vmapbuf(struct buf *bp)
{
caddr_t addr, kva;
vm_offset_t pa;
int pidx;
struct vm_page *m;
pmap_t pmap;
GIANT_REQUIRED;
if ((bp->b_flags & B_PHYS) == 0)
panic("vmapbuf");
pmap = &curproc->p_vmspace->vm_pmap;
for (addr = (caddr_t)trunc_page(bp->b_data), pidx = 0;
addr < bp->b_data + bp->b_bufsize;
addr += PAGE_SIZE, pidx++) {
/*
* Do the vm_fault if needed; do the copy-on-write thing
* when reading stuff off device into memory.
*/
vm_fault_quick((addr >= bp->b_data) ? addr : bp->b_data,
(bp->b_iocmd == BIO_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ);
pa = trunc_page(pmap_extract(pmap, (vm_offset_t) addr));
if (pa == 0)
panic("vmapbuf: page not present");
m = PHYS_TO_VM_PAGE(pa);
vm_page_hold(m);
bp->b_pages[pidx] = m;
}
if (pidx > btoc(MAXPHYS))
panic("vmapbuf: mapped more than MAXPHYS");
pmap_qenter((vm_offset_t)bp->b_saveaddr, bp->b_pages, pidx);
kva = bp->b_saveaddr;
bp->b_npages = pidx;
bp->b_saveaddr = bp->b_data;
bp->b_data = kva + (((vm_offset_t) bp->b_data) & PAGE_MASK);
}
/*
* Free the io map PTEs associated with this IO operation.
* We also invalidate the TLB entries and restore the original b_addr.
*/
void
vunmapbuf(struct buf *bp)
{
int pidx;
int npages;
GIANT_REQUIRED;
if ((bp->b_flags & B_PHYS) == 0)
panic("vunmapbuf");
npages = bp->b_npages;
pmap_qremove(trunc_page((vm_offset_t)bp->b_data),
npages);
for (pidx = 0; pidx < npages; pidx++)
vm_page_unhold(bp->b_pages[pidx]);
bp->b_data = bp->b_saveaddr;
}
/*
* Reset back to firmware.
*/
void
cpu_reset()
{
OF_exit();
}
/*
* Software interrupt handler for queued VM system processing.
*/
void
swi_vm(void *dummy)
{
#if 0 /* XXX: Don't have busdma stuff yet */
if (busdma_swi_pending != 0)
busdma_swi();
#endif
}
/*
* Tell whether this address is in some physical memory region.
* Currently used by the kernel coredump code in order to avoid
* dumping the ``ISA memory hole'' which could cause indefinite hangs,
* or other unpredictable behaviour.
*/
int
is_physical_memory(addr)
vm_offset_t addr;
{
/*
* stuff other tests for known memory-mapped devices (PCI?)
* here
*/
return 1;
}
/*
* KSE functions
*/
void
cpu_thread_exit(struct thread *td)
{
return;
}
void
cpu_thread_setup(struct thread *td)
{
return;
}
void
cpu_set_upcall(struct thread *td, void *pcb)
{
return;
}
void
cpu_set_upcall_kse(struct thread *td, struct kse *ke)
{
return;
}