1 /* 2 * Copyright (c) 1988 University of Utah. 3 * Copyright (c) 1982, 1986, 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the Systems Programming Group of the University of Utah Computer 8 * Science Department. 9 * 10 * %sccs.include.redist.c% 11 * 12 * from: Utah $Hdr: vm_machdep.c 1.21 91/04/06$ 13 * 14 * @(#)vm_machdep.c 8.1 (Berkeley) 06/10/93 15 */ 16 17 #include <sys/param.h> 18 #include <sys/systm.h> 19 #include <sys/proc.h> 20 #include <sys/malloc.h> 21 #include <sys/buf.h> 22 #include <sys/vnode.h> 23 #include <sys/user.h> 24 25 #include <machine/cpu.h> 26 27 #include <vm/vm.h> 28 #include <vm/vm_kern.h> 29 #include <hp300/hp300/pte.h> 30 31 /* 32 * Finish a fork operation, with process p2 nearly set up. 33 * Copy and update the kernel stack and pcb, making the child 34 * ready to run, and marking it so that it can return differently 35 * than the parent. Returns 1 in the child process, 0 in the parent. 36 * We currently double-map the user area so that the stack is at the same 37 * address in each process; in the future we will probably relocate 38 * the frame pointers on the stack after copying. 39 */ 40 cpu_fork(p1, p2) 41 register struct proc *p1, *p2; 42 { 43 register struct user *up = p2->p_addr; 44 int offset; 45 extern caddr_t getsp(); 46 extern char kstack[]; 47 48 p2->p_md.md_regs = p1->p_md.md_regs; 49 p2->p_md.md_flags = (p1->p_md.md_flags & ~(MDP_AST|MDP_HPUXTRACE)); 50 51 /* 52 * Copy pcb and stack from proc p1 to p2. 53 * We do this as cheaply as possible, copying only the active 54 * part of the stack. The stack and pcb need to agree; 55 * this is tricky, as the final pcb is constructed by savectx, 56 * but its frame isn't yet on the stack when the stack is copied. 57 * swtch compensates for this when the child eventually runs. 58 * This should be done differently, with a single call 59 * that copies and updates the pcb+stack, 60 * replacing the bcopy and savectx. 61 */ 62 p2->p_addr->u_pcb = p1->p_addr->u_pcb; 63 offset = getsp() - kstack; 64 bcopy((caddr_t)kstack + offset, (caddr_t)p2->p_addr + offset, 65 (unsigned) ctob(UPAGES) - offset); 66 67 PMAP_ACTIVATE(&p2->p_vmspace->vm_pmap, &up->u_pcb, 0); 68 69 /* 70 * Arrange for a non-local goto when the new process 71 * is started, to resume here, returning nonzero from setjmp. 72 */ 73 if (savectx(up, 1)) { 74 /* 75 * Return 1 in child. 76 */ 77 return (1); 78 } 79 return (0); 80 } 81 82 /* 83 * cpu_exit is called as the last action during exit. 84 * We release the address space and machine-dependent resources, 85 * including the memory for the user structure and kernel stack. 86 * Once finished, we call swtch_exit, which switches to a temporary 87 * pcb and stack and never returns. We block memory allocation 88 * until swtch_exit has made things safe again. 89 */ 90 cpu_exit(p) 91 struct proc *p; 92 { 93 94 vmspace_free(p->p_vmspace); 95 96 (void) splimp(); 97 kmem_free(kernel_map, (vm_offset_t)p->p_addr, ctob(UPAGES)); 98 swtch_exit(); 99 /* NOTREACHED */ 100 } 101 102 /* 103 * Dump the machine specific header information at the start of a core dump. 104 */ 105 cpu_coredump(p, vp, cred) 106 struct proc *p; 107 struct vnode *vp; 108 struct ucred *cred; 109 { 110 int error; 111 112 #ifdef HPUXCOMPAT 113 /* 114 * If we loaded from an HP-UX format binary file we dump enough 115 * of an HP-UX style user struct so that the HP-UX debuggers can 116 * grok it. 117 */ 118 if (p->p_md.md_flags & MDP_HPUX) 119 return (hpuxdumpu(vp, cred)); 120 #endif 121 return (vn_rdwr(UIO_WRITE, vp, (caddr_t) p->p_addr, ctob(UPAGES), 122 (off_t)0, UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, cred, (int *) NULL, 123 p)); 124 } 125 126 /* 127 * Move pages from one kernel virtual address to another. 128 * Both addresses are assumed to reside in the Sysmap, 129 * and size must be a multiple of CLSIZE. 130 */ 131 pagemove(from, to, size) 132 register caddr_t from, to; 133 int size; 134 { 135 register struct pte *fpte, *tpte; 136 137 if (size % CLBYTES) 138 panic("pagemove"); 139 fpte = kvtopte(from); 140 tpte = kvtopte(to); 141 while (size > 0) { 142 *tpte++ = *fpte; 143 *(int *)fpte++ = PG_NV; 144 TBIS(from); 145 TBIS(to); 146 from += NBPG; 147 to += NBPG; 148 size -= NBPG; 149 } 150 DCIS(); 151 } 152 153 /* 154 * Map `size' bytes of physical memory starting at `paddr' into 155 * kernel VA space at `vaddr'. Read/write and cache-inhibit status 156 * are specified by `prot'. 157 */ 158 physaccess(vaddr, paddr, size, prot) 159 caddr_t vaddr, paddr; 160 register int size, prot; 161 { 162 register struct pte *pte; 163 register u_int page; 164 165 pte = kvtopte(vaddr); 166 page = (u_int)paddr & PG_FRAME; 167 for (size = btoc(size); size; size--) { 168 *(int *)pte++ = PG_V | prot | page; 169 page += NBPG; 170 } 171 TBIAS(); 172 } 173 174 physunaccess(vaddr, size) 175 caddr_t vaddr; 176 register int size; 177 { 178 register struct pte *pte; 179 180 pte = kvtopte(vaddr); 181 for (size = btoc(size); size; size--) 182 *(int *)pte++ = PG_NV; 183 TBIAS(); 184 } 185 186 /* 187 * Set a red zone in the kernel stack after the u. area. 188 * We don't support a redzone right now. It really isn't clear 189 * that it is a good idea since, if the kernel stack were to roll 190 * into a write protected page, the processor would lock up (since 191 * it cannot create an exception frame) and we would get no useful 192 * post-mortem info. Currently, under the DEBUG option, we just 193 * check at every clock interrupt to see if the current k-stack has 194 * gone too far (i.e. into the "redzone" page) and if so, panic. 195 * Look at _lev6intr in locore.s for more details. 196 */ 197 /*ARGSUSED*/ 198 setredzone(pte, vaddr) 199 struct pte *pte; 200 caddr_t vaddr; 201 { 202 } 203 204 /* 205 * Convert kernel VA to physical address 206 */ 207 kvtop(addr) 208 register caddr_t addr; 209 { 210 vm_offset_t va; 211 212 va = pmap_extract(kernel_pmap, (vm_offset_t)addr); 213 if (va == 0) 214 panic("kvtop: zero page frame"); 215 return((int)va); 216 } 217 218 extern vm_map_t phys_map; 219 220 /* 221 * Map an IO request into kernel virtual address space. 222 * 223 * XXX we allocate KVA space by using kmem_alloc_wait which we know 224 * allocates space without backing physical memory. This implementation 225 * is a total crock, the multiple mappings of these physical pages should 226 * be reflected in the higher-level VM structures to avoid problems. 227 */ 228 vmapbuf(bp) 229 register struct buf *bp; 230 { 231 register int npf; 232 register caddr_t addr; 233 register long flags = bp->b_flags; 234 struct proc *p; 235 int off; 236 vm_offset_t kva; 237 register vm_offset_t pa; 238 239 if ((flags & B_PHYS) == 0) 240 panic("vmapbuf"); 241 addr = bp->b_saveaddr = bp->b_un.b_addr; 242 off = (int)addr & PGOFSET; 243 p = bp->b_proc; 244 npf = btoc(round_page(bp->b_bcount + off)); 245 kva = kmem_alloc_wait(phys_map, ctob(npf)); 246 bp->b_un.b_addr = (caddr_t) (kva + off); 247 while (npf--) { 248 pa = pmap_extract(vm_map_pmap(&p->p_vmspace->vm_map), 249 (vm_offset_t)addr); 250 if (pa == 0) 251 panic("vmapbuf: null page frame"); 252 pmap_enter(vm_map_pmap(phys_map), kva, trunc_page(pa), 253 VM_PROT_READ|VM_PROT_WRITE, TRUE); 254 addr += PAGE_SIZE; 255 kva += PAGE_SIZE; 256 } 257 } 258 259 /* 260 * Free the io map PTEs associated with this IO operation. 261 */ 262 vunmapbuf(bp) 263 register struct buf *bp; 264 { 265 register int npf; 266 register caddr_t addr = bp->b_un.b_addr; 267 vm_offset_t kva; 268 269 if ((bp->b_flags & B_PHYS) == 0) 270 panic("vunmapbuf"); 271 npf = btoc(round_page(bp->b_bcount + ((int)addr & PGOFSET))); 272 kva = (vm_offset_t)((int)addr & ~PGOFSET); 273 kmem_free_wakeup(phys_map, kva, ctob(npf)); 274 bp->b_un.b_addr = bp->b_saveaddr; 275 bp->b_saveaddr = NULL; 276 } 277