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/*-
* 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 $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
* $Id: vm_machdep.c,v 1.5 1998/12/04 10:52:47 dfr Exp $
*/
/*
* 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/buf.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <machine/clock.h>
#include <machine/cpu.h>
#include <machine/fpu.h>
#include <machine/md_var.h>
#include <machine/prom.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_prot.h>
#include <sys/lock.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
*/
void
vm_fault_quick(v, prot)
caddr_t v;
int prot;
{
if (prot & VM_PROT_WRITE)
subyte(v, fubyte(v));
else
fubyte(v);
}
/*
* 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(p1, p2)
register struct proc *p1, *p2;
{
struct user *up = p2->p_addr;
int i;
p2->p_md.md_tf = p1->p_md.md_tf;
p2->p_md.md_flags = p1->p_md.md_flags & MDP_FPUSED;
/*
* Cache the physical address of the pcb, so we can
* swap to it easily.
*/
p2->p_md.md_pcbpaddr = (void*) vtophys((vm_offset_t) &up->u_pcb);
/*
* Copy floating point state from the FP chip to the PCB
* if this process has state stored there.
*/
if (p1 == fpcurproc) {
alpha_pal_wrfen(1);
savefpstate(&fpcurproc->p_addr->u_pcb.pcb_fp);
alpha_pal_wrfen(0);
}
/*
* Copy pcb and stack from proc p1 to p2.
* We do this as cheaply as possible, copying only the active
* part of the stack. The stack and pcb need to agree;
*/
p2->p_addr->u_pcb = p1->p_addr->u_pcb;
p2->p_addr->u_pcb.pcb_hw.apcb_usp = alpha_pal_rdusp();
/*
* Set the floating point state.
*/
if ((p2->p_addr->u_pcb.pcb_fp_control & IEEE_INHERIT) == 0) {
p2->p_addr->u_pcb.pcb_fp_control = (IEEE_TRAP_ENABLE_INV
| IEEE_TRAP_ENABLE_DZE
| IEEE_TRAP_ENABLE_OVF);
p2->p_addr->u_pcb.pcb_fp.fpr_cr = (FPCR_DYN_NORMAL
| FPCR_INED | FPCR_UNFD);
}
/*
* Arrange for a non-local goto when the new process
* is started, to resume here, returning nonzero from setjmp.
*/
#ifdef DIAGNOSTIC
if (p1 != curproc)
panic("cpu_fork: curproc");
if ((up->u_pcb.pcb_hw.apcb_flags & ALPHA_PCB_FLAGS_FEN) != 0)
printf("DANGER WILL ROBINSON: FEN SET IN cpu_fork!\n");
#endif
/*
* create the child's kernel stack, from scratch.
*/
{
struct trapframe *p2tf;
/*
* 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.
*/
p2tf = p2->p_md.md_tf = (struct trapframe *)
((char *)p2->p_addr + USPACE - sizeof(struct trapframe));
bcopy(p1->p_md.md_tf, p2->p_md.md_tf,
sizeof(struct trapframe));
/*
* Set up return-value registers as fork() libc stub expects.
*/
p2tf->tf_regs[FRAME_V0] = p1->p_pid; /* parent's pid */
p2tf->tf_regs[FRAME_A3] = 0; /* no error */
p2tf->tf_regs[FRAME_A4] = 1; /* is child */
/*
* Arrange for continuation at child_return(), which
* will return to exception_return(). Note that the child
* process doesn't stay in the kernel for long!
*
* This is an inlined version of cpu_set_kpc.
*/
up->u_pcb.pcb_hw.apcb_ksp = (u_int64_t)p2tf;
up->u_pcb.pcb_context[0] =
(u_int64_t)child_return; /* s0: pc */
up->u_pcb.pcb_context[1] =
(u_int64_t)exception_return; /* s1: ra */
up->u_pcb.pcb_context[2] = (u_long) p2; /* s2: a0 */
up->u_pcb.pcb_context[7] =
(u_int64_t)switch_trampoline; /* ra: assembly magic */
}
}
/*
* 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(p, func, arg)
struct proc *p;
void (*func) __P((void *));
void *arg;
{
/*
* Note that the trap frame follows the args, so the function
* is really called like this: func(arg, frame);
*/
p->p_addr->u_pcb.pcb_context[0] = (u_long) func;
p->p_addr->u_pcb.pcb_context[2] = (u_long) 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(p)
register struct proc *p;
{
if (p == fpcurproc)
fpcurproc = NULL;
(void) splhigh();
cnt.v_swtch++;
cpu_switch(p);
panic("cpu_exit");
}
void
cpu_wait(p)
struct proc *p;
{
/* drop per-process resources */
pmap_dispose_proc(p);
/* and clean-out the vmspace */
vmspace_free(p->p_vmspace);
}
/*
* Dump the machine specific header information at the start of a core dump.
*/
int
cpu_coredump(p, vp, cred)
struct proc *p;
struct vnode *vp;
struct ucred *cred;
{
return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES),
(off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *)NULL,
p));
}
#ifdef notyet
static void
setredzone(pte, vaddr)
u_short *pte;
caddr_t vaddr;
{
/* eventually do this by setting up an expand-down stack segment
for ss0: selector, allowing stack access down to top of u.
this means though that protection violations need to be handled
thru a double fault exception that must do an integral task
switch to a known good context, within which a dump can be
taken. a sensible scheme might be to save the initial context
used by sched (that has physical memory mapped 1:1 at bottom)
and take the dump while still in mapped mode */
}
#endif
/*
* 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(bp)
register struct buf *bp;
{
register caddr_t addr, v, kva;
vm_offset_t pa;
if ((bp->b_flags & B_PHYS) == 0)
panic("vmapbuf");
for (v = bp->b_saveaddr, addr = (caddr_t)trunc_page(bp->b_data);
addr < bp->b_data + bp->b_bufsize;
addr += PAGE_SIZE, v += PAGE_SIZE) {
/*
* 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_flags&B_READ)?(VM_PROT_READ|VM_PROT_WRITE):VM_PROT_READ);
pa = trunc_page(pmap_kextract((vm_offset_t) addr));
if (pa == 0)
panic("vmapbuf: page not present");
vm_page_hold(PHYS_TO_VM_PAGE(pa));
pmap_kenter((vm_offset_t) v, pa);
}
kva = bp->b_saveaddr;
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(bp)
register struct buf *bp;
{
register caddr_t addr;
vm_offset_t pa;
if ((bp->b_flags & B_PHYS) == 0)
panic("vunmapbuf");
for (addr = (caddr_t)trunc_page(bp->b_data);
addr < bp->b_data + bp->b_bufsize;
addr += PAGE_SIZE) {
pa = trunc_page(pmap_kextract((vm_offset_t) addr));
pmap_kremove((vm_offset_t) addr);
vm_page_unhold(PHYS_TO_VM_PAGE(pa));
}
bp->b_data = bp->b_saveaddr;
}
/*
* Force reset the processor by invalidating the entire address space!
*/
void
cpu_reset()
{
prom_halt(0);
}
/*
* Grow the user stack to allow for 'sp'. This version grows the stack in
* chunks of SGROWSIZ.
*/
int
grow(p, sp)
struct proc *p;
size_t sp;
{
unsigned int nss;
caddr_t v;
struct vmspace *vm = p->p_vmspace;
if ((caddr_t)sp <= vm->vm_maxsaddr || sp >= USRSTACK)
return (1);
nss = roundup(USRSTACK - sp, PAGE_SIZE);
if (nss > p->p_rlimit[RLIMIT_STACK].rlim_cur)
return (0);
if (vm->vm_ssize && roundup(vm->vm_ssize << PAGE_SHIFT,
SGROWSIZ) < nss) {
int grow_amount;
/*
* If necessary, grow the VM that the stack occupies
* to allow for the rlimit. This allows us to not have
* to allocate all of the VM up-front in execve (which
* is expensive).
* Grow the VM by the amount requested rounded up to
* the nearest SGROWSIZ to provide for some hysteresis.
*/
grow_amount = roundup((nss - (vm->vm_ssize << PAGE_SHIFT)), SGROWSIZ);
v = (char *)USRSTACK - roundup(vm->vm_ssize << PAGE_SHIFT,
SGROWSIZ) - grow_amount;
/*
* If there isn't enough room to extend by SGROWSIZ, then
* just extend to the maximum size
*/
if (v < vm->vm_maxsaddr) {
v = vm->vm_maxsaddr;
grow_amount = MAXSSIZ - (vm->vm_ssize << PAGE_SHIFT);
}
if ((grow_amount == 0) || (vm_map_find(&vm->vm_map, NULL, 0, (vm_offset_t *)&v,
grow_amount, FALSE, VM_PROT_ALL, VM_PROT_ALL, 0) != KERN_SUCCESS)) {
return (0);
}
vm->vm_ssize += grow_amount >> PAGE_SHIFT;
}
return (1);
}
static int cnt_prezero;
SYSCTL_INT(_machdep, OID_AUTO, cnt_prezero, CTLFLAG_RD, &cnt_prezero, 0, "");
/*
* Implement the pre-zeroed page mechanism.
* This routine is called from the idle loop.
*/
int
vm_page_zero_idle()
{
static int free_rover;
vm_page_t m;
int s;
/*
* XXX
* We stop zeroing pages when there are sufficent prezeroed pages.
* This threshold isn't really needed, except we want to
* bypass unneeded calls to vm_page_list_find, and the
* associated cache flush and latency. The pre-zero will
* still be called when there are significantly more
* non-prezeroed pages than zeroed pages. The threshold
* of half the number of reserved pages is arbitrary, but
* approximately the right amount. Eventually, we should
* perhaps interrupt the zero operation when a process
* is found to be ready to run.
*/
if (cnt.v_free_count - vm_page_zero_count <= cnt.v_free_reserved / 2)
return (0);
#ifdef SMP
if (try_mplock()) {
#endif
s = splvm();
m = vm_page_list_find(PQ_FREE, free_rover);
if (m != NULL) {
--(*vm_page_queues[m->queue].lcnt);
TAILQ_REMOVE(vm_page_queues[m->queue].pl, m, pageq);
m->queue = PQ_NONE;
splx(s);
#if 0
rel_mplock();
#endif
pmap_zero_page(VM_PAGE_TO_PHYS(m));
#if 0
get_mplock();
#endif
(void)splvm();
m->queue = PQ_ZERO + m->pc;
++(*vm_page_queues[m->queue].lcnt);
TAILQ_INSERT_HEAD(vm_page_queues[m->queue].pl, m,
pageq);
free_rover = (free_rover + PQ_PRIME3) & PQ_L2_MASK;
++vm_page_zero_count;
++cnt_prezero;
}
splx(s);
#ifdef SMP
rel_mplock();
#endif
return (1);
#ifdef SMP
}
#endif
return (0);
}
/*
* Software interrupt handler for queued VM system processing.
*/
void
swi_vm()
{
#if 0
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;
}
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