Annotation of sys/arch/alpha/alpha/vm_machdep.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: vm_machdep.c,v 1.33 2007/05/27 20:59:24 miod Exp $ */
! 2: /* $NetBSD: vm_machdep.c,v 1.55 2000/03/29 03:49:48 simonb Exp $ */
! 3:
! 4: /*
! 5: * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University.
! 6: * All rights reserved.
! 7: *
! 8: * Author: Chris G. Demetriou
! 9: *
! 10: * Permission to use, copy, modify and distribute this software and
! 11: * its documentation is hereby granted, provided that both the copyright
! 12: * notice and this permission notice appear in all copies of the
! 13: * software, derivative works or modified versions, and any portions
! 14: * thereof, and that both notices appear in supporting documentation.
! 15: *
! 16: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
! 17: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
! 18: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
! 19: *
! 20: * Carnegie Mellon requests users of this software to return to
! 21: *
! 22: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
! 23: * School of Computer Science
! 24: * Carnegie Mellon University
! 25: * Pittsburgh PA 15213-3890
! 26: *
! 27: * any improvements or extensions that they make and grant Carnegie the
! 28: * rights to redistribute these changes.
! 29: */
! 30:
! 31: #include <sys/param.h>
! 32: #include <sys/systm.h>
! 33: #include <sys/proc.h>
! 34: #include <sys/signalvar.h>
! 35: #include <sys/malloc.h>
! 36: #include <sys/buf.h>
! 37: #include <sys/vnode.h>
! 38: #include <sys/user.h>
! 39: #include <sys/core.h>
! 40: #include <sys/exec.h>
! 41:
! 42: #include <uvm/uvm_extern.h>
! 43:
! 44: #include <machine/cpu.h>
! 45: #include <machine/pmap.h>
! 46: #include <machine/reg.h>
! 47:
! 48:
! 49: /*
! 50: * Dump the machine specific header information at the start of a core dump.
! 51: */
! 52: int
! 53: cpu_coredump(p, vp, cred, chdr)
! 54: struct proc *p;
! 55: struct vnode *vp;
! 56: struct ucred *cred;
! 57: struct core *chdr;
! 58: {
! 59: int error;
! 60: struct md_coredump cpustate;
! 61: struct coreseg cseg;
! 62:
! 63: CORE_SETMAGIC(*chdr, COREMAGIC, MID_ALPHA, 0);
! 64: chdr->c_hdrsize = ALIGN(sizeof(*chdr));
! 65: chdr->c_seghdrsize = ALIGN(sizeof(cseg));
! 66: chdr->c_cpusize = sizeof(cpustate);
! 67:
! 68: cpustate.md_tf = *p->p_md.md_tf;
! 69: cpustate.md_tf.tf_regs[FRAME_SP] = alpha_pal_rdusp(); /* XXX */
! 70: if (p->p_md.md_flags & MDP_FPUSED) {
! 71: if (p->p_addr->u_pcb.pcb_fpcpu != NULL)
! 72: fpusave_proc(p, 1);
! 73: cpustate.md_fpstate = p->p_addr->u_pcb.pcb_fp;
! 74: } else
! 75: bzero(&cpustate.md_fpstate, sizeof(cpustate.md_fpstate));
! 76:
! 77: CORE_SETMAGIC(cseg, CORESEGMAGIC, MID_ALPHA, CORE_CPU);
! 78: cseg.c_addr = 0;
! 79: cseg.c_size = chdr->c_cpusize;
! 80:
! 81: error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&cseg, chdr->c_seghdrsize,
! 82: (off_t)chdr->c_hdrsize, UIO_SYSSPACE,
! 83: IO_NODELOCKED|IO_UNIT, cred, NULL, p);
! 84: if (error)
! 85: return error;
! 86:
! 87: error = vn_rdwr(UIO_WRITE, vp, (caddr_t)&cpustate, sizeof(cpustate),
! 88: (off_t)(chdr->c_hdrsize + chdr->c_seghdrsize), UIO_SYSSPACE,
! 89: IO_NODELOCKED|IO_UNIT, cred, NULL, p);
! 90:
! 91: if (!error)
! 92: chdr->c_nseg++;
! 93:
! 94: return error;
! 95: }
! 96:
! 97: /*
! 98: * cpu_exit is called as the last action during exit.
! 99: * We block interrupts and call switch_exit. switch_exit switches
! 100: * to proc0's PCB and stack, then jumps into the middle of cpu_switch,
! 101: * as if it were switching from proc0.
! 102: */
! 103: void
! 104: cpu_exit(p)
! 105: struct proc *p;
! 106: {
! 107:
! 108: if (p->p_addr->u_pcb.pcb_fpcpu != NULL)
! 109: fpusave_proc(p, 0);
! 110:
! 111: /*
! 112: * Deactivate the exiting address space before the vmspace
! 113: * is freed. Note that we will continue to run on this
! 114: * vmspace's context until the switch to proc0 in switch_exit().
! 115: */
! 116: pmap_deactivate(p);
! 117:
! 118: (void) splhigh();
! 119: switch_exit(p);
! 120: /* NOTREACHED */
! 121: }
! 122:
! 123: /*
! 124: * Finish a fork operation, with process p2 nearly set up.
! 125: * Copy and update the pcb and trap frame, making the child ready to run.
! 126: *
! 127: * Rig the child's kernel stack so that it will start out in
! 128: * switch_trampoline() and call child_return() with p2 as an
! 129: * argument. This causes the newly-created child process to go
! 130: * directly to user level with an apparent return value of 0 from
! 131: * fork(), while the parent process returns normally.
! 132: *
! 133: * p1 is the process being forked;
! 134: *
! 135: * If an alternate user-level stack is requested (with non-zero values
! 136: * in both the stack and stacksize args), set up the user stack pointer
! 137: * accordingly.
! 138: */
! 139: void
! 140: cpu_fork(p1, p2, stack, stacksize, func, arg)
! 141: struct proc *p1, *p2;
! 142: void *stack;
! 143: size_t stacksize;
! 144: void (*func)(void *);
! 145: void *arg;
! 146: {
! 147: struct user *up = p2->p_addr;
! 148:
! 149: p2->p_md.md_tf = p1->p_md.md_tf;
! 150:
! 151: #ifndef NO_IEEE
! 152: p2->p_md.md_flags = p1->p_md.md_flags & (MDP_FPUSED | MDP_FP_C);
! 153: #else
! 154: p2->p_md.md_flags = p1->p_md.md_flags & MDP_FPUSED;
! 155: #endif
! 156:
! 157: /*
! 158: * Cache the physical address of the pcb, so we can
! 159: * swap to it easily.
! 160: */
! 161: p2->p_md.md_pcbpaddr = (void *)vtophys((vaddr_t)&up->u_pcb);
! 162:
! 163: /*
! 164: * Copy floating point state from the FP chip to the PCB
! 165: * if this process has state stored there.
! 166: */
! 167: if (p1->p_addr->u_pcb.pcb_fpcpu != NULL)
! 168: fpusave_proc(p1, 1);
! 169:
! 170: /*
! 171: * Copy pcb and stack from proc p1 to p2.
! 172: * We do this as cheaply as possible, copying only the active
! 173: * part of the stack. The stack and pcb need to agree;
! 174: */
! 175: p2->p_addr->u_pcb = p1->p_addr->u_pcb;
! 176: p2->p_addr->u_pcb.pcb_hw.apcb_usp = alpha_pal_rdusp();
! 177:
! 178: /*
! 179: * Arrange for a non-local goto when the new process
! 180: * is started, to resume here, returning nonzero from setjmp.
! 181: */
! 182: #ifdef DIAGNOSTIC
! 183: /*
! 184: * If p1 != curproc && p1 == &proc0, we are creating a kernel
! 185: * thread.
! 186: */
! 187: if (p1 != curproc && p1 != &proc0)
! 188: panic("cpu_fork: curproc");
! 189: if ((up->u_pcb.pcb_hw.apcb_flags & ALPHA_PCB_FLAGS_FEN) != 0)
! 190: printf("DANGER WILL ROBINSON: FEN SET IN cpu_fork!\n");
! 191: #endif
! 192:
! 193: /*
! 194: * create the child's kernel stack, from scratch.
! 195: */
! 196: {
! 197: struct trapframe *p2tf;
! 198:
! 199: /*
! 200: * Pick a stack pointer, leaving room for a trapframe;
! 201: * copy trapframe from parent so return to user mode
! 202: * will be to right address, with correct registers.
! 203: */
! 204: p2tf = p2->p_md.md_tf = (struct trapframe *)
! 205: ((char *)p2->p_addr + USPACE - sizeof(struct trapframe));
! 206: bcopy(p1->p_md.md_tf, p2->p_md.md_tf,
! 207: sizeof(struct trapframe));
! 208:
! 209: /*
! 210: * Set up return-value registers as fork() libc stub expects.
! 211: */
! 212: p2tf->tf_regs[FRAME_V0] = p1->p_pid; /* parent's pid */
! 213: p2tf->tf_regs[FRAME_A3] = 0; /* no error */
! 214: p2tf->tf_regs[FRAME_A4] = 1; /* is child */
! 215:
! 216: /*
! 217: * If specificed, give the child a different stack.
! 218: */
! 219: if (stack != NULL)
! 220: p2tf->tf_regs[FRAME_SP] = (u_long)stack + stacksize;
! 221:
! 222: /*
! 223: * Arrange for continuation at child_return(), which
! 224: * will return to exception_return(). Note that the child
! 225: * process doesn't stay in the kernel for long!
! 226: */
! 227: up->u_pcb.pcb_hw.apcb_ksp = (u_int64_t)p2tf;
! 228: up->u_pcb.pcb_context[0] = (u_int64_t)func;
! 229: up->u_pcb.pcb_context[1] =
! 230: (u_int64_t)exception_return; /* s1: ra */
! 231: up->u_pcb.pcb_context[2] = (u_int64_t)arg;
! 232: up->u_pcb.pcb_context[7] =
! 233: (u_int64_t)switch_trampoline; /* ra: assembly magic */
! 234: up->u_pcb.pcb_context[8] = ALPHA_PSL_IPL_0; /* ps: IPL */
! 235: }
! 236: }
! 237:
! 238: /*
! 239: * Map a user I/O request into kernel virtual address space.
! 240: * Note: the pages are already locked by uvm_vslock(), so we
! 241: * do not need to pass an access_type to pmap_enter().
! 242: */
! 243: void
! 244: vmapbuf(bp, len)
! 245: struct buf *bp;
! 246: vsize_t len;
! 247: {
! 248: vaddr_t faddr, taddr, off;
! 249: paddr_t pa;
! 250: struct proc *p;
! 251:
! 252: if ((bp->b_flags & B_PHYS) == 0)
! 253: panic("vmapbuf");
! 254: p = bp->b_proc;
! 255: faddr = trunc_page((vaddr_t)bp->b_saveaddr = bp->b_data);
! 256: off = (vaddr_t)bp->b_data - faddr;
! 257: len = round_page(off + len);
! 258: taddr = uvm_km_valloc_wait(phys_map, len);
! 259: bp->b_data = (caddr_t)(taddr + off);
! 260: len = atop(len);
! 261: while (len--) {
! 262: if (pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map),
! 263: faddr, &pa) == FALSE)
! 264: panic("vmapbuf: null page frame");
! 265: pmap_enter(vm_map_pmap(phys_map), taddr, trunc_page(pa),
! 266: VM_PROT_READ|VM_PROT_WRITE, PMAP_WIRED);
! 267: faddr += PAGE_SIZE;
! 268: taddr += PAGE_SIZE;
! 269: }
! 270: pmap_update(vm_map_pmap(phys_map));
! 271: }
! 272:
! 273: /*
! 274: * Unmap a previously-mapped user I/O request.
! 275: */
! 276: void
! 277: vunmapbuf(bp, len)
! 278: struct buf *bp;
! 279: vsize_t len;
! 280: {
! 281: vaddr_t addr, off;
! 282:
! 283: if ((bp->b_flags & B_PHYS) == 0)
! 284: panic("vunmapbuf");
! 285: addr = trunc_page((vaddr_t)bp->b_data);
! 286: off = (vaddr_t)bp->b_data - addr;
! 287: len = round_page(off + len);
! 288: pmap_remove(vm_map_pmap(phys_map), addr, addr + len);
! 289: pmap_update(vm_map_pmap(phys_map));
! 290: uvm_km_free_wakeup(phys_map, addr, len);
! 291: bp->b_data = bp->b_saveaddr;
! 292: bp->b_saveaddr = NULL;
! 293: }
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