Annotation of sys/arch/i386/i386/vm_machdep.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: vm_machdep.c,v 1.52 2007/05/27 20:59:25 miod Exp $ */
! 2: /* $NetBSD: vm_machdep.c,v 1.61 1996/05/03 19:42:35 christos Exp $ */
! 3:
! 4: /*-
! 5: * Copyright (c) 1995 Charles M. Hannum. All rights reserved.
! 6: * Copyright (c) 1982, 1986 The Regents of the University of California.
! 7: * Copyright (c) 1989, 1990 William Jolitz
! 8: * All rights reserved.
! 9: *
! 10: * This code is derived from software contributed to Berkeley by
! 11: * the Systems Programming Group of the University of Utah Computer
! 12: * Science Department, and William Jolitz.
! 13: *
! 14: * Redistribution and use in source and binary forms, with or without
! 15: * modification, are permitted provided that the following conditions
! 16: * are met:
! 17: * 1. Redistributions of source code must retain the above copyright
! 18: * notice, this list of conditions and the following disclaimer.
! 19: * 2. Redistributions in binary form must reproduce the above copyright
! 20: * notice, this list of conditions and the following disclaimer in the
! 21: * documentation and/or other materials provided with the distribution.
! 22: * 3. Neither the name of the University nor the names of its contributors
! 23: * may be used to endorse or promote products derived from this software
! 24: * without specific prior written permission.
! 25: *
! 26: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
! 27: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
! 28: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
! 29: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
! 30: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
! 31: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
! 32: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 33: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
! 34: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
! 35: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
! 36: * SUCH DAMAGE.
! 37: *
! 38: * @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
! 39: */
! 40:
! 41: /*
! 42: * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
! 43: */
! 44:
! 45: #include <sys/param.h>
! 46: #include <sys/systm.h>
! 47: #include <sys/proc.h>
! 48: #include <sys/signalvar.h>
! 49: #include <sys/malloc.h>
! 50: #include <sys/vnode.h>
! 51: #include <sys/buf.h>
! 52: #include <sys/user.h>
! 53: #include <sys/core.h>
! 54: #include <sys/exec.h>
! 55: #include <sys/ptrace.h>
! 56:
! 57: #include <uvm/uvm_extern.h>
! 58:
! 59: #include <machine/cpu.h>
! 60: #include <machine/gdt.h>
! 61: #include <machine/reg.h>
! 62: #include <machine/specialreg.h>
! 63:
! 64: #include "npx.h"
! 65:
! 66: /*
! 67: * Finish a fork operation, with process p2 nearly set up.
! 68: * Copy and update the kernel stack and pcb, making the child
! 69: * ready to run, and marking it so that it can return differently
! 70: * than the parent. Returns 1 in the child process, 0 in the parent.
! 71: * We currently double-map the user area so that the stack is at the same
! 72: * address in each process; in the future we will probably relocate
! 73: * the frame pointers on the stack after copying.
! 74: */
! 75: void
! 76: cpu_fork(struct proc *p1, struct proc *p2, void *stack, size_t stacksize,
! 77: void (*func)(void *), void *arg)
! 78: {
! 79: struct pcb *pcb = &p2->p_addr->u_pcb;
! 80: struct trapframe *tf;
! 81: struct switchframe *sf;
! 82:
! 83: #if NNPX > 0
! 84: npxsave_proc(p1, 1);
! 85: #endif
! 86:
! 87: p2->p_md.md_flags = p1->p_md.md_flags;
! 88:
! 89: /* Copy pcb from proc p1 to p2. */
! 90: if (p1 == curproc) {
! 91: /* Sync the PCB before we copy it. */
! 92: savectx(curpcb);
! 93: }
! 94: #ifdef DIAGNOSTIC
! 95: else if (p1 != &proc0)
! 96: panic("cpu_fork: curproc");
! 97: #endif
! 98: *pcb = p1->p_addr->u_pcb;
! 99:
! 100: /*
! 101: * Preset these so that gdt_compact() doesn't get confused if called
! 102: * during the allocations below.
! 103: *
! 104: * Note: pcb_ldt_sel is handled in the pmap_activate() call when
! 105: * we run the new process.
! 106: */
! 107: p2->p_md.md_tss_sel = GSEL(GNULL_SEL, SEL_KPL);
! 108:
! 109: /* Fix up the TSS. */
! 110: pcb->pcb_tss.tss_ss0 = GSEL(GDATA_SEL, SEL_KPL);
! 111: pcb->pcb_tss.tss_esp0 = (int)p2->p_addr + USPACE - 16;
! 112:
! 113: p2->p_md.md_tss_sel = tss_alloc(pcb);
! 114:
! 115: /*
! 116: * Copy the trapframe, and arrange for the child to return directly
! 117: * through rei().
! 118: */
! 119: p2->p_md.md_regs = tf = (struct trapframe *)pcb->pcb_tss.tss_esp0 - 1;
! 120: *tf = *p1->p_md.md_regs;
! 121:
! 122: /*
! 123: * If specified, give the child a different stack.
! 124: */
! 125: if (stack != NULL)
! 126: tf->tf_esp = (u_int)stack + stacksize;
! 127:
! 128: sf = (struct switchframe *)tf - 1;
! 129: sf->sf_ppl = 0;
! 130: sf->sf_esi = (int)func;
! 131: sf->sf_ebx = (int)arg;
! 132: sf->sf_eip = (int)proc_trampoline;
! 133: pcb->pcb_esp = (int)sf;
! 134: }
! 135:
! 136: /*
! 137: * cpu_exit is called as the last action during exit.
! 138: *
! 139: * We clean up a little and then call switch_exit() with the old proc as an
! 140: * argument. switch_exit() first switches to proc0's context, then does the
! 141: * vmspace_free() and kmem_free() that we don't do here, and finally jumps
! 142: * into switch() to wait for another process to wake up.
! 143: */
! 144: void
! 145: cpu_exit(struct proc *p)
! 146: {
! 147: #if NNPX > 0
! 148: /* If we were using the FPU, forget about it. */
! 149: if (p->p_addr->u_pcb.pcb_fpcpu != NULL)
! 150: npxsave_proc(p, 0);
! 151: #endif
! 152:
! 153: pmap_deactivate(p);
! 154: switch_exit(p);
! 155: }
! 156:
! 157: void
! 158: cpu_wait(struct proc *p)
! 159: {
! 160: tss_free(p->p_md.md_tss_sel);
! 161: }
! 162:
! 163: /*
! 164: * Dump the machine specific segment at the start of a core dump.
! 165: */
! 166: struct md_core {
! 167: struct reg intreg;
! 168: struct fpreg freg;
! 169: };
! 170:
! 171: int
! 172: cpu_coredump(struct proc *p, struct vnode *vp, struct ucred *cred,
! 173: struct core *chdr)
! 174: {
! 175: struct md_core md_core;
! 176: struct coreseg cseg;
! 177: int error;
! 178:
! 179: CORE_SETMAGIC(*chdr, COREMAGIC, MID_I386, 0);
! 180: chdr->c_hdrsize = ALIGN(sizeof(*chdr));
! 181: chdr->c_seghdrsize = ALIGN(sizeof(cseg));
! 182: chdr->c_cpusize = sizeof(md_core);
! 183:
! 184: /* Save integer registers. */
! 185: error = process_read_regs(p, &md_core.intreg);
! 186: if (error)
! 187: return error;
! 188:
! 189: /* Save floating point registers. */
! 190: error = process_read_fpregs(p, &md_core.freg);
! 191: if (error)
! 192: return error;
! 193:
! 194: CORE_SETMAGIC(cseg, CORESEGMAGIC, MID_I386, CORE_CPU);
! 195: cseg.c_addr = 0;
! 196: cseg.c_size = chdr->c_cpusize;
! 197:
! 198: error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&cseg, chdr->c_seghdrsize,
! 199: (off_t)chdr->c_hdrsize, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred,
! 200: NULL, p);
! 201: if (error)
! 202: return error;
! 203:
! 204: error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&md_core, sizeof(md_core),
! 205: (off_t)(chdr->c_hdrsize + chdr->c_seghdrsize), UIO_SYSSPACE,
! 206: IO_NODELOCKED|IO_UNIT, cred, NULL, p);
! 207: if (error)
! 208: return error;
! 209:
! 210: chdr->c_nseg++;
! 211: return 0;
! 212: }
! 213:
! 214: /*
! 215: * Convert kernel VA to physical address
! 216: */
! 217: int
! 218: kvtop(caddr_t addr)
! 219: {
! 220: paddr_t pa;
! 221:
! 222: if (pmap_extract(pmap_kernel(), (vaddr_t)addr, &pa) == FALSE)
! 223: panic("kvtop: zero page frame");
! 224: return((int)pa);
! 225: }
! 226:
! 227: /*
! 228: * Map an user IO request into kernel virtual address space.
! 229: */
! 230: void
! 231: vmapbuf(struct buf *bp, vsize_t len)
! 232: {
! 233: vaddr_t faddr, taddr, off;
! 234: paddr_t fpa;
! 235:
! 236: if ((bp->b_flags & B_PHYS) == 0)
! 237: panic("vmapbuf");
! 238: faddr = trunc_page((vaddr_t)(bp->b_saveaddr = bp->b_data));
! 239: off = (vaddr_t)bp->b_data - faddr;
! 240: len = round_page(off + len);
! 241: taddr= uvm_km_valloc_wait(phys_map, len);
! 242: bp->b_data = (caddr_t)(taddr + off);
! 243: /*
! 244: * The region is locked, so we expect that pmap_pte() will return
! 245: * non-NULL.
! 246: * XXX: unwise to expect this in a multithreaded environment.
! 247: * anything can happen to a pmap between the time we lock a
! 248: * region, release the pmap lock, and then relock it for
! 249: * the pmap_extract().
! 250: *
! 251: * no need to flush TLB since we expect nothing to be mapped
! 252: * where we we just allocated (TLB will be flushed when our
! 253: * mapping is removed).
! 254: */
! 255: while (len) {
! 256: pmap_extract(vm_map_pmap(&bp->b_proc->p_vmspace->vm_map),
! 257: faddr, &fpa);
! 258: pmap_kenter_pa(taddr, fpa, VM_PROT_READ|VM_PROT_WRITE);
! 259: faddr += PAGE_SIZE;
! 260: taddr += PAGE_SIZE;
! 261: len -= PAGE_SIZE;
! 262: }
! 263: pmap_update(pmap_kernel());
! 264: }
! 265:
! 266: /*
! 267: * Free the io map PTEs associated with this IO operation.
! 268: * We also invalidate the TLB entries and restore the original b_addr.
! 269: */
! 270: void
! 271: vunmapbuf(struct buf *bp, vsize_t len)
! 272: {
! 273: vaddr_t addr, off;
! 274:
! 275: if ((bp->b_flags & B_PHYS) == 0)
! 276: panic("vunmapbuf");
! 277: addr = trunc_page((vaddr_t)bp->b_data);
! 278: off = (vaddr_t)bp->b_data - addr;
! 279: len = round_page(off + len);
! 280: pmap_kremove(addr, len);
! 281: pmap_update(pmap_kernel());
! 282: uvm_km_free_wakeup(phys_map, addr, len);
! 283: bp->b_data = bp->b_saveaddr;
! 284: bp->b_saveaddr = 0;
! 285: }
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