+/*
+ * Copyright (c) 1992 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * This software was developed by the Computer Systems Engineering group
+ * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
+ * contributed to Berkeley.
+ *
+ * %sccs.include.redist.c%
+ *
+ * @(#)vm_machdep.c 7.1 (Berkeley) %G%
+ *
+ * from: $Header: vm_machdep.c,v 1.9 92/06/17 05:22:25 torek Exp $ (LBL)
+ */
+
+#include "sys/param.h"
+#include "sys/systm.h"
+#include "sys/proc.h"
+#include "sys/user.h"
+#include "sys/malloc.h"
+#include "sys/buf.h"
+#include "sys/exec.h"
+#include "sys/vnode.h"
+
+#include "vm/vm.h"
+#include "vm/vm_kern.h"
+
+#include "machine/cpu.h"
+#include "machine/frame.h"
+
+/*
+ * Move pages from one kernel virtual address to another.
+ */
+pagemove(from, to, size)
+ register caddr_t from, to;
+ int size;
+{
+ register vm_offset_t pa;
+
+ if (size & CLOFSET || (int)from & CLOFSET || (int)to & CLOFSET)
+ panic("pagemove 1");
+ while (size > 0) {
+ pa = pmap_extract(kernel_pmap, (vm_offset_t)from);
+ if (pa == 0)
+ panic("pagemove 2");
+ pmap_remove(kernel_pmap,
+ (vm_offset_t)from, (vm_offset_t)from + PAGE_SIZE);
+ pmap_enter(kernel_pmap,
+ (vm_offset_t)to, pa, VM_PROT_READ|VM_PROT_WRITE, 1);
+ from += PAGE_SIZE;
+ to += PAGE_SIZE;
+ size -= PAGE_SIZE;
+ }
+}
+
+/*
+ * Map an IO request into kernel virtual address space.
+ *
+ * ### pmap_enter distributes this mapping to all contexts ... maybe
+ * we should avoid this extra work
+ *
+ * THIS IS NOT IDEAL -- WE NEED ONLY VIRTUAL SPACE BUT kmem_alloc_wait
+ * DOES WORK DESIGNED TO SUPPLY PHYSICAL SPACE ON DEMAND LATER
+ */
+vmapbuf(bp)
+ register struct buf *bp;
+{
+ register int npf;
+ register caddr_t addr;
+ struct proc *p;
+ int off;
+ vm_offset_t kva;
+ register vm_offset_t pa;
+
+ if ((bp->b_flags & B_PHYS) == 0)
+ panic("vmapbuf");
+ addr = bp->b_saveaddr = bp->b_un.b_addr;
+ off = (int)addr & PGOFSET;
+ p = bp->b_proc;
+ npf = btoc(round_page(bp->b_bcount + off));
+ kva = kmem_alloc_wait(phys_map, ctob(npf));
+ bp->b_un.b_addr = (caddr_t) (kva + off);
+ while (npf--) {
+ pa = pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map),
+ (vm_offset_t)addr);
+ if (pa == 0)
+ panic("vmapbuf: null page frame");
+ pmap_enter(vm_map_pmap(phys_map), kva,
+ trunc_page(pa) | PMAP_NC,
+ VM_PROT_READ|VM_PROT_WRITE, 1);
+ addr += PAGE_SIZE;
+ kva += PAGE_SIZE;
+ }
+}
+
+/*
+ * Free the io map addresses associated with this IO operation.
+ */
+vunmapbuf(bp)
+ register struct buf *bp;
+{
+ register vm_offset_t kva = (vm_offset_t)bp->b_un.b_addr;
+ register int off, npf;
+
+ if ((bp->b_flags & B_PHYS) == 0)
+ panic("vunmapbuf");
+ off = (int)kva & PGOFSET;
+ kva -= off;
+ npf = btoc(round_page(bp->b_bcount + off));
+ kmem_free_wakeup(phys_map, kva, ctob(npf));
+ bp->b_un.b_addr = bp->b_saveaddr;
+ bp->b_saveaddr = NULL;
+ cache_flush(bp->b_un.b_addr, bp->b_bcount - bp->b_resid);
+}
+
+/*
+ * Allocate physical memory space in the dvma virtual address range.
+ */
+caddr_t
+dvma_malloc(size)
+ size_t size;
+{
+ vm_size_t vsize;
+ caddr_t va;
+
+ vsize = round_page(size);
+ va = (caddr_t)kmem_alloc(phys_map, vsize);
+ if (va == NULL)
+ panic("dvma_malloc");
+ kvm_uncache(va, vsize >> PGSHIFT);
+ return (va);
+}
+
+/*
+ * The offset of the topmost frame in the kernel stack.
+ */
+#define TOPFRAMEOFF (UPAGES*NBPG-sizeof(struct trapframe)-sizeof(struct frame))
+
+/*
+ * Finish a fork operation, with process p2 nearly set up.
+ * Copy and update the kernel stack and pcb, making the child
+ * ready to run, and marking it so that it can return differently
+ * than the parent. Returns 1 in the child process, 0 in the parent.
+ *
+ * This function relies on the fact that the pcb is
+ * the first element in struct user.
+ */
+cpu_fork(p1, p2)
+ register struct proc *p1, *p2;
+{
+ register struct pcb *opcb = &p1->p_addr->u_pcb;
+ register struct pcb *npcb = &p2->p_addr->u_pcb;
+ register u_int sp, topframe, off, ssize;
+
+ /*
+ * Save all the registers to p1's stack or, in the case of
+ * user registers and invalid stack pointers, to opcb.
+ * snapshot() also sets the given pcb's pcb_sp and pcb_psr
+ * to the current %sp and %psr, and sets pcb_pc to a stub
+ * which returns 1. We then copy the whole pcb to p2;
+ * when swtch() selects p2 to run, it will run at the stub,
+ * rather than at the copying code below, and cpu_fork
+ * will return 1.
+ *
+ * Note that the order `*npcb = *opcb, snapshot(npcb)' is wrong,
+ * as user registers might then wind up only in opcb.
+ * We could call save_user_windows first,
+ * but that would only save 3 stores anyway.
+ *
+ * If process p1 has an FPU state, we must copy it. If it is
+ * the FPU user, we must save the FPU state first.
+ */
+ snapshot(opcb);
+ bcopy((caddr_t)opcb, (caddr_t)npcb, sizeof(struct pcb));
+ if (p1->p_md.md_fpstate) {
+ if (p1 == fpproc)
+ savefpstate(p1->p_md.md_fpstate);
+ p2->p_md.md_fpstate = malloc(sizeof(struct fpstate),
+ M_SUBPROC, M_WAITOK);
+ bcopy(p1->p_md.md_fpstate, p2->p_md.md_fpstate,
+ sizeof(struct fpstate));
+ } else
+ p2->p_md.md_fpstate = NULL;
+
+ /*
+ * Copy the active part of the kernel stack,
+ * then adjust each kernel sp -- the frame pointer
+ * in the top frame is a user sp -- in the child's copy,
+ * including the initial one in the child's pcb.
+ */
+ sp = npcb->pcb_sp; /* points to old kernel stack */
+ ssize = (u_int)opcb + UPAGES * NBPG - sp;
+ if (ssize >= UPAGES * NBPG - sizeof(struct pcb))
+ panic("cpu_fork 1");
+ off = (u_int)npcb - (u_int)opcb;
+ qcopy((caddr_t)sp, (caddr_t)sp + off, ssize);
+ sp += off;
+ npcb->pcb_sp = sp;
+ topframe = (u_int)npcb + TOPFRAMEOFF;
+ while (sp < topframe)
+ sp = ((struct rwindow *)sp)->rw_in[6] += off;
+ if (sp != topframe)
+ panic("cpu_fork 2");
+ /*
+ * This might be unnecessary, but it may be possible for the child
+ * to run in ptrace or sendsig before it returns from fork.
+ */
+ p2->p_md.md_tf = (struct trapframe *)((int)p1->p_md.md_tf + off);
+ return (0);
+}
+
+/*
+ * cpu_exit is called as the last action during exit.
+ * We release the address space and machine-dependent resources,
+ * including the memory for the user structure and kernel stack.
+ * Since the latter is also the interrupt stack, we release it
+ * from assembly code after switching to a temporary pcb+stack.
+ */
+cpu_exit(p)
+ struct proc *p;
+{
+ register struct fpstate *fs;
+
+ if ((fs = p->p_md.md_fpstate) != NULL) {
+ if (p == fpproc) {
+ savefpstate(fs);
+ fpproc = NULL;
+ }
+ free((void *)fs, M_SUBPROC);
+ }
+ vmspace_free(p->p_vmspace);
+ swtchexit(kernel_map, p->p_addr, round_page(ctob(UPAGES)));
+ /* NOTREACHED */
+}
+
+/*
+ * cpu_coredump is called to write a core dump header.
+ * (should this be defined elsewhere? machdep.c?)
+ */
+int
+cpu_coredump(p, vp, cred)
+ struct proc *p;
+ struct vnode *vp;
+ struct ucred *cred;
+{
+ register struct user *up = p->p_addr;
+
+ up->u_md.md_tf = *p->p_md.md_tf;
+ if (p->p_md.md_fpstate)
+ up->u_md.md_fpstate = *p->p_md.md_fpstate;
+ else
+ bzero((caddr_t)&up->u_md.md_fpstate, sizeof(struct fpstate));
+ return (vn_rdwr(UIO_WRITE, vp, (caddr_t)up, ctob(UPAGES), (off_t)0,
+ UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *)NULL, p));
+}
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