NetBSD/sys/arch/atari/atari/vm_machdep.c

/*	$NetBSD: vm_machdep.c,v 1.31 2000/01/20 22:18:55 sommerfeld Exp $	*/

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1982, 1986, 1990 The Regents of the University of California.
 * 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.
 *
 * 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: Utah $Hdr: vm_machdep.c 1.21 91/04/06$
 *
 *	@(#)vm_machdep.c	7.10 (Berkeley) 5/7/91
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/malloc.h>
#include <sys/vnode.h>
#include <sys/buf.h>
#include <sys/core.h>
#include <sys/exec_aout.h>
#include <m68k/reg.h>
#include <m68k/cpu.h>
#include <m68k/cacheops.h>

#include <vm/vm.h>
#include <sys/user.h>
#include <vm/vm_kern.h>

#include <uvm/uvm_extern.h>

#include <machine/pte.h>
#include <machine/cpu.h>

/*
 * Finish a fork operation, with process p2 nearly set up.
 * Copy and update the pcb and trap frame, making the child ready to run.
 * 
 * Rig the child's kernel stack so that it will start out in
 * proc_trampoline() and call child_return() with p2 as an
 * argument. This causes the newly-created child process to go
 * directly to user level with an apparent return value of 0 from
 * fork(), while the parent process returns normally.
 *
 * p1 is the process being forked; if p1 == &proc0, we are creating
 * a kernel thread, and the return path will later be changed in cpu_set_kpc.
 *
 * If an alternate user-level stack is requested (with non-zero values
 * in both the stack and stacksize args), set up the user stack pointer
 * accordingly.
 */
void
cpu_fork(p1, p2, stack, stacksize)
	register struct proc *p1, *p2;
	void *stack;
	size_t stacksize;
{
	register struct pcb *pcb = &p2->p_addr->u_pcb;
	register struct trapframe *tf;
	register struct switchframe *sf;
	extern struct pcb *curpcb;

	p2->p_md.md_flags = p1->p_md.md_flags;

	/* Copy pcb from proc p1 to p2. */
	if (p1 == curproc) {
		/* Sync the PCB before we copy it. */
		savectx(curpcb);
	}
#ifdef DIAGNOSTIC
	else if (p1 != &proc0)
		panic("cpu_fork: curproc");
#endif
	*pcb = p1->p_addr->u_pcb;

	/*
	 * Copy the trap frame, and arrange for the child to return directly
	 * through child_return().  Note the in-line cpu_set_kpc().
	 */
	tf = (struct trapframe *)((u_int)p2->p_addr + USPACE) - 1;
	p2->p_md.md_regs = (int *)tf;
	*tf = *(struct trapframe *)p1->p_md.md_regs;

	/*
	 * If specified, give the child a different stack.
	 */
	if (stack != NULL)
		tf->tf_regs[15] = (u_int)stack + stacksize;

	sf = (struct switchframe *)tf - 1;
	sf->sf_pc = (u_int)proc_trampoline;
	pcb->pcb_regs[6] = (int)child_return;	/* A2 */
	pcb->pcb_regs[7] = (int)p2;		/* A3 */
	pcb->pcb_regs[11] = (int)sf;		/* SSP */
}

/*
 * cpu_set_kpc:
 *
 * Arrange for in-kernel execution of a process to continue at the
 * named pc, as if the code at that address were called as a function
 * with the supplied argument.
 *
 * Note that it's assumed that when the named process returns, rei()
 * should be invoked, to return to user mode.
 */
void
cpu_set_kpc(p, pc, arg)
	struct proc	*p;
	void		(*pc) __P((void *));
	void		*arg;
{
	struct pcb *pcbp;
	struct switchframe *sf;

	pcbp = &p->p_addr->u_pcb;
	sf = (struct switchframe *)pcbp->pcb_regs[11];
	sf->sf_pc = (u_int)proc_trampoline;
	pcbp->pcb_regs[6] = (int)pc;		/* A2 */
	pcbp->pcb_regs[7] = (int)arg;		/* A3 */
}

/*
 * cpu_exit is called as the last action during exit.
 *
 * Block context switches and then call switch_exit() which will
 * switch to another process thus we never return.
 */
void
cpu_exit(p)
	struct proc *p;
{

	(void)splhigh();
	uvmexp.swtch++;
	switch_exit(p);
	/* NOTREACHED */
}

/*
 * Move pages from one kernel virtual address to another.
 * Both addresses are assumed to reside in the Sysmap,
 * and size must be a multiple of CLSIZE.
 */
void
pagemove(from, to, size)
	register caddr_t	from, to;
		 size_t		size;
{
	paddr_t pa;
	boolean_t rv;

#ifdef DEBUG
	if (size & PGOFSET)
		panic("pagemove");
#endif
	while (size > 0) {
		rv = pmap_extract(pmap_kernel(), (vaddr_t)from, &pa);
#ifdef DEBUG
		if (rv == FALSE)
			panic("pagemove 2");
		if (pmap_extract(pmap_kernel(), (vaddr_t)to, NULL) == TRUE)
			panic("pagemove 3");
#endif
		pmap_remove(pmap_kernel(),
			    (vaddr_t)from, (vaddr_t)from + PAGE_SIZE);
		pmap_enter(pmap_kernel(),
			   (vaddr_t)to, pa, VM_PROT_READ|VM_PROT_WRITE,
			   VM_PROT_READ|VM_PROT_WRITE|PMAP_WIRED);
		from += PAGE_SIZE;
		to += PAGE_SIZE;
		size -= PAGE_SIZE;
	}
}

/*
 * Map `size' bytes of physical memory starting at `paddr' into
 * kernel VA space at `vaddr'.  Read/write and cache-inhibit status
 * are specified by `prot'.
 */ 
void
physaccess(vaddr, paddr, size, prot)
	caddr_t vaddr, paddr;
	register int size, prot;
{
	u_int *pte;
	register u_int page;

	if (mmutype == MMU_68040 && (prot & PG_CI) == 0)
		prot |= PG_CCB;		/*   set cacheable, copyback */
	pte = kvtopte(vaddr);
	page = (u_int)paddr & PG_FRAME;
	for (size = btoc(size); size; size--) {
		*pte++ = PG_V | prot | page;
		page += NBPG;
	}
	TBIAS();
}

void
physunaccess(vaddr, size)
	caddr_t vaddr;
	register int size;
{
	u_int *pte;

	pte = kvtopte(vaddr);
	for (size = btoc(size); size; size--)
		*pte++ = PG_NV;
	TBIAS();
}

/*
 * Dump the machine specific segment at the start of a core dump.
 * This means the CPU and FPU registers.  The format used here is
 * the same one ptrace uses, so gdb can be machine independent.
 *
 * XXX - Generate Sun format core dumps for Sun executables?
 */
struct md_core {
	struct reg intreg;
	struct fpreg freg;
};
int
cpu_coredump(p, vp, cred, chdr)
	struct proc *p;
	struct vnode *vp;
	struct ucred *cred;
	struct core *chdr;
{
	int error;
	struct md_core md_core;
	struct coreseg cseg;
	register struct user *up = p->p_addr;
	register int i;

	CORE_SETMAGIC(*chdr, COREMAGIC, MID_MACHINE, 0);
	chdr->c_hdrsize = ALIGN(sizeof(*chdr));
	chdr->c_seghdrsize = ALIGN(sizeof(cseg));
	chdr->c_cpusize = sizeof(md_core);

	/* Save integer registers. */
	{
		register struct frame *f;

		f = (struct frame*) p->p_md.md_regs;
		for (i = 0; i < 16; i++) {
			md_core.intreg.r_regs[i] = f->f_regs[i];
		}
		md_core.intreg.r_sr = f->f_sr;
		md_core.intreg.r_pc = f->f_pc;
	}
	if (fputype) {
		register struct fpframe *f;

		f = &up->u_pcb.pcb_fpregs;
		m68881_save(f);
		for (i = 0; i < (8*3); i++) {
			md_core.freg.r_regs[i] = f->fpf_regs[i];
		}
		md_core.freg.r_fpcr  = f->fpf_fpcr;
		md_core.freg.r_fpsr  = f->fpf_fpsr;
		md_core.freg.r_fpiar = f->fpf_fpiar;
	} else {
		bzero((caddr_t)&md_core.freg, sizeof(md_core.freg));
	}

	CORE_SETMAGIC(cseg, CORESEGMAGIC, MID_MACHINE, CORE_CPU);
	cseg.c_addr = 0;
	cseg.c_size = chdr->c_cpusize;

	error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&cseg, chdr->c_seghdrsize,
	    (off_t)chdr->c_hdrsize, UIO_SYSSPACE,
	    IO_NODELOCKED|IO_UNIT, cred, NULL, p);
	if (error)
		return error;

	error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&md_core, sizeof(md_core),
	    (off_t)(chdr->c_hdrsize + chdr->c_seghdrsize), UIO_SYSSPACE,
	    IO_NODELOCKED|IO_UNIT, cred, NULL, p);

	if (!error)
		chdr->c_nseg++;

	return error;
}

/*
 * Set a red zone in the kernel stack after the u. area.
 * We don't support a redzone right now.  It really isn't clear
 * that it is a good idea since, if the kernel stack were to roll
 * into a write protected page, the processor would lock up (since
 * it cannot create an exception frame) and we would get no useful
 * post-mortem info.  Currently, under the DEBUG option, we just
 * check at every clock interrupt to see if the current k-stack has
 * gone too far (i.e. into the "redzone" page) and if so, panic.
 * Look at _lev6intr in locore.s for more details.
 */
/*ARGSUSED*/
void
setredzone(pte, vaddr)
	u_int *pte;
	caddr_t vaddr;
{
}

/*
 * Convert kernel VA to physical address
 */
paddr_t
kvtop(addr)
	register caddr_t addr;
{
	paddr_t pa;

	if (pmap_extract(pmap_kernel(), (vaddr_t)addr, &pa) == FALSE)
		panic("kvtop: zero page frame");
	return(pa);
}

extern vm_map_t phys_map;

/*
 * Map a user I/O request into kernel virtual address space.
 * Note: the pages are already locked by uvm_vslock(), so we
 * do not need to pass an access_type to pmap_enter().
 */
void
vmapbuf(bp, len)
	struct buf *bp;
	vsize_t len;
{
	struct pmap *upmap, *kpmap;
	vm_offset_t uva;	/* User VA (map from) */
	vm_offset_t kva;	/* Kernel VA (new to) */
	vm_offset_t pa; 	/* physical address */
	vsize_t off;

	if ((bp->b_flags & B_PHYS) == 0)
		panic("vmapbuf");

	uva = m68k_trunc_page(bp->b_saveaddr = bp->b_data);
	off = (vm_offset_t)bp->b_data - uva;
	len = m68k_round_page(off + len);
	kva = uvm_km_valloc_wait(phys_map, len);
	bp->b_data = (caddr_t)(kva + off);

	upmap = vm_map_pmap(&bp->b_proc->p_vmspace->vm_map);
	kpmap = vm_map_pmap(phys_map);
	do {
		if (pmap_extract(upmap, uva, &pa) == FALSE)
			panic("vmapbuf: null page frame");
		pmap_enter(kpmap, kva, pa, VM_PROT_READ|VM_PROT_WRITE,
		    PMAP_WIRED);
		uva += PAGE_SIZE;
		kva += PAGE_SIZE;
		len -= PAGE_SIZE;
	} while (len);
}

/*
 * Unmap a previously-mapped user I/O request.
 */
void
vunmapbuf(bp, len)
	struct buf *bp;
	vsize_t len;
{
	vm_offset_t kva;
	vsize_t off;

	if ((bp->b_flags & B_PHYS) == 0)
		panic("vunmapbuf");

	kva = m68k_trunc_page(bp->b_data);
	off = (vm_offset_t)bp->b_data - kva;
	len = m68k_round_page(off + len);

	/*
	 * pmap_remove() is unnecessary here, as kmem_free_wakeup()
	 * will do it for us.
	 */
	uvm_km_free_wakeup(phys_map, kva, len);
	bp->b_data = bp->b_saveaddr;
	bp->b_saveaddr = 0;
}