osfmk/i386/mp_desc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * @OSF_COPYRIGHT@
  24  */
  25 /*
  26  * Mach Operating System
  27  * Copyright (c) 1991,1990 Carnegie Mellon University
  28  * All Rights Reserved.
  29  *
  30  * Permission to use, copy, modify and distribute this software and its
  31  * documentation is hereby granted, provided that both the copyright
  32  * notice and this permission notice appear in all copies of the
  33  * software, derivative works or modified versions, and any portions
  34  * thereof, and that both notices appear in supporting documentation.
  35  *
  36  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  37  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  38  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  39  *
  40  * Carnegie Mellon requests users of this software to return to
  41  *
  42  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  43  *  School of Computer Science
  44  *  Carnegie Mellon University
  45  *  Pittsburgh PA 15213-3890
  46  *
  47  * any improvements or extensions that they make and grant Carnegie Mellon
  48  * the rights to redistribute these changes.
  49  */
  50
  51 /*
  52  */
  53
  54
  55 #include <kern/cpu_number.h>
  56 #include <kern/kalloc.h>
  57 #include <kern/cpu_data.h>
  58 #include <mach/machine.h>
  59 #include <vm/vm_kern.h>
  60
  61 #include <i386/mp_desc.h>
  62 #include <i386/lock.h>
  63 #include <i386/misc_protos.h>
  64 #include <i386/mp.h>
  65 #include <i386/pmap.h>
  66
  67 #include <kern/misc_protos.h>
  68
  69 #include <mach_kdb.h>
  70
  71 /*
  72  * The i386 needs an interrupt stack to keep the PCB stack from being
  73  * overrun by interrupts.  All interrupt stacks MUST lie at lower addresses
  74  * than any thread`s kernel stack.
  75  */
  76
  77 /*
  78  * First cpu`s interrupt stack.
  79  */
  80 extern char             intstack[];     /* bottom */
  81 extern char             eintstack[];    /* top */
  82
  83 /*
  84  * Per-cpu data area pointers.
  85  * The master cpu (cpu 0) has its data area statically allocated;
  86  * others are allocated dynamically and this array is updated at runtime.
  87  */
  88 cpu_data_t      cpu_data_master;
  89 cpu_data_t      *cpu_data_ptr[MAX_CPUS] = { [0] &cpu_data_master };
  90
  91 decl_simple_lock_data(,cpu_lock);       /* protects real_ncpus */
  92 unsigned int    real_ncpus = 1;
  93 unsigned int    max_ncpus = MAX_CPUS;
  94
  95 /*
  96  * Multiprocessor i386/i486 systems use a separate copy of the
  97  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
  98  * are separate to avoid lock contention: the i386 uses locked
  99  * memory cycles to access the descriptor tables.  The TSS is
 100  * separate since each processor needs its own kernel stack,
 101  * and since using a TSS marks it busy.
 102  */
 103
 104 /*
 105  * Allocate and initialize the per-processor descriptor tables.
 106  */
 107
 108 struct fake_descriptor ldt_desc_pattern = {
 109         (unsigned int) 0,
 110         LDTSZ * sizeof(struct fake_descriptor) - 1,
 111         0,
 112         ACC_P|ACC_PL_K|ACC_LDT
 113 };
 114 struct fake_descriptor tss_desc_pattern = {
 115         (unsigned int) 0,
 116         sizeof(struct i386_tss),
 117         0,
 118         ACC_P|ACC_PL_K|ACC_TSS
 119 };
 120
 121 struct fake_descriptor cpudata_desc_pattern = {
 122         (unsigned int) 0,
 123         sizeof(cpu_data_t)-1,
 124         SZ_32,
 125         ACC_P|ACC_PL_K|ACC_DATA_W
 126 };
 127
 128 void
 129 mp_desc_init(
 130         cpu_data_t      *cdp,
 131         boolean_t       is_boot_cpu)
 132 {
 133         struct mp_desc_table    *mpt = cdp->cpu_desc_tablep;
 134         cpu_desc_index_t        *cdt = &cdp->cpu_desc_index;
 135
 136         if (is_boot_cpu) {
 137             /*
 138              * Master CPU uses the tables built at boot time.
 139              * Just set the TSS and GDT pointers.
 140              */
 141             cdt->cdi_ktss = &ktss;
 142 #if     MACH_KDB
 143             cdt->cdi_dbtss = &dbtss;
 144 #endif  /* MACH_KDB */
 145             cdt->cdi_gdt = gdt;
 146             cdt->cdi_idt = idt;
 147             cdt->cdi_ldt = ldt;
 148
 149         } else {
 150
 151             cdt->cdi_ktss = &mpt->ktss;
 152             cdt->cdi_gdt = mpt->gdt;
 153             cdt->cdi_idt = mpt->idt;
 154             cdt->cdi_ldt = mpt->ldt;
 155
 156             /*
 157              * Copy the tables
 158              */
 159             bcopy((char *)idt,
 160                   (char *)mpt->idt,
 161                   sizeof(idt));
 162             bcopy((char *)gdt,
 163                   (char *)mpt->gdt,
 164                   sizeof(gdt));
 165             bcopy((char *)ldt,
 166                   (char *)mpt->ldt,
 167                   sizeof(ldt));
 168             bzero((char *)&mpt->ktss,
 169                   sizeof(struct i386_tss));
 170
 171 #if     MACH_KDB
 172             cdt->cdi_dbtss = &dbtss;
 173             bcopy((char *)&dbtss,
 174                   (char *)&mpt->dbtss,
 175                   sizeof(struct i386_tss));
 176 #endif  /* MACH_KDB */
 177
 178             /*
 179              * Fix up the entries in the GDT to point to
 180              * this LDT and this TSS.
 181              */
 182             mpt->gdt[sel_idx(KERNEL_LDT)] = ldt_desc_pattern;
 183             mpt->gdt[sel_idx(KERNEL_LDT)].offset = (vm_offset_t) mpt->ldt;
 184             fix_desc(&mpt->gdt[sel_idx(KERNEL_LDT)], 1);
 185
 186             mpt->gdt[sel_idx(KERNEL_TSS)] = tss_desc_pattern;
 187             mpt->gdt[sel_idx(KERNEL_TSS)].offset = (vm_offset_t) &mpt->ktss;
 188             fix_desc(&mpt->gdt[sel_idx(KERNEL_TSS)], 1);
 189
 190             mpt->gdt[sel_idx(CPU_DATA_GS)] = cpudata_desc_pattern;
 191             mpt->gdt[sel_idx(CPU_DATA_GS)].offset = (vm_offset_t) cdp;
 192             fix_desc(&mpt->gdt[sel_idx(CPU_DATA_GS)], 1);
 193
 194 #if     MACH_KDB
 195             mpt->gdt[sel_idx(DEBUG_TSS)] = tss_desc_pattern;
 196             mpt->gdt[sel_idx(DEBUG_TSS)].offset = (vm_offset_t) &mpt->dbtss;
 197             fix_desc(&mpt->gdt[sel_idx(DEBUG_TSS)], 1);
 198
 199             mpt->dbtss.esp0 = (int)(db_task_stack_store +
 200                     (INTSTACK_SIZE * (cpu + 1)) - sizeof (natural_t));
 201             mpt->dbtss.esp = mpt->dbtss.esp0;
 202             mpt->dbtss.eip = (int)&db_task_start;
 203 #endif  /* MACH_KDB */
 204
 205             mpt->ktss.ss0 = KERNEL_DS;
 206             mpt->ktss.io_bit_map_offset = 0x0FFF;       /* no IO bitmap */
 207         }
 208 }
 209
 210 cpu_data_t *
 211 cpu_data_alloc(boolean_t is_boot_cpu)
 212 {
 213         int             ret;
 214         cpu_data_t      *cdp;
 215
 216         if (is_boot_cpu) {
 217                 assert(real_ncpus == 1);
 218                 simple_lock_init(&cpu_lock, 0);
 219                 cdp = &cpu_data_master;
 220                 if (cdp->cpu_processor == NULL) {
 221                         cdp->cpu_processor = cpu_processor_alloc(TRUE);
 222                         cdp->cpu_pmap = pmap_cpu_alloc(TRUE);
 223                         cdp->cpu_this = cdp;
 224                         cdp->cpu_int_stack_top = (vm_offset_t) eintstack;
 225                         mp_desc_init(cdp, TRUE);
 226                 }
 227                 return cdp;
 228         }
 229
 230         /* Check count before making allocations */
 231         if (real_ncpus >= max_ncpus)
 232                 return NULL;
 233
 234         /*
 235          * Allocate per-cpu data:
 236          */
 237         ret = kmem_alloc(kernel_map,
 238                          (vm_offset_t *) &cdp, sizeof(cpu_data_t));
 239         if (ret != KERN_SUCCESS) {
 240                 printf("cpu_data_alloc() failed, ret=%d\n", ret);
 241                 goto abort;
 242         }
 243         bzero((void*) cdp, sizeof(cpu_data_t));
 244         cdp->cpu_this = cdp;
 245
 246         /*
 247          * Allocate interrupt stack:
 248          */
 249         ret = kmem_alloc(kernel_map,
 250                          (vm_offset_t *) &cdp->cpu_int_stack_top,
 251                          INTSTACK_SIZE);
 252         if (ret != KERN_SUCCESS) {
 253                 printf("cpu_data_alloc() int stack failed, ret=%d\n", ret);
 254                 goto abort;
 255         }
 256         bzero((void*) cdp->cpu_int_stack_top, INTSTACK_SIZE);
 257         cdp->cpu_int_stack_top += INTSTACK_SIZE;
 258
 259         /*
 260          * Allocate descriptor table:
 261          */
 262         ret = kmem_alloc(kernel_map,
 263                          (vm_offset_t *) &cdp->cpu_desc_tablep,
 264                          sizeof(struct mp_desc_table));
 265         if (ret != KERN_SUCCESS) {
 266                 printf("cpu_data_alloc() desc_table failed, ret=%d\n", ret);
 267                 goto abort;
 268         }
 269
 270         simple_lock(&cpu_lock);
 271         if (real_ncpus >= max_ncpus) {
 272                 simple_unlock(&cpu_lock);
 273                 goto abort;
 274         }
 275         cpu_data_ptr[real_ncpus] = cdp;
 276         cdp->cpu_number = real_ncpus;
 277         real_ncpus++;
 278         simple_unlock(&cpu_lock);
 279
 280         kprintf("cpu_data_alloc(%d) 0x%x desc_table: 0x%x "
 281                 "int_stack: 0x%x-0x%x\n",
 282                 cdp->cpu_number, cdp, cdp->cpu_desc_tablep,
 283                 cdp->cpu_int_stack_top - INTSTACK_SIZE, cdp->cpu_int_stack_top);
 284
 285         return cdp;
 286
 287 abort:
 288         if (cdp) {
 289                 if (cdp->cpu_desc_tablep)
 290                         kfree((void *) cdp->cpu_desc_tablep,
 291                                 sizeof(*cdp->cpu_desc_tablep));
 292                 if (cdp->cpu_int_stack_top)
 293                         kfree((void *) (cdp->cpu_int_stack_top - INTSTACK_SIZE),
 294                                 INTSTACK_SIZE);
 295                 kfree((void *) cdp, sizeof(*cdp));
 296         }
 297         return NULL;
 298 }
 299
 300 boolean_t
 301 valid_user_segment_selectors(uint16_t cs,
 302                              uint16_t ss,
 303                              uint16_t ds,
 304                              uint16_t es,
 305                              uint16_t fs,
 306                              uint16_t gs)
 307 {
 308         return valid_user_code_selector(cs)  &&
 309                valid_user_stack_selector(ss) &&
 310                valid_user_data_selector(ds)  &&
 311                valid_user_data_selector(es)  &&
 312                valid_user_data_selector(fs)  &&
 313                valid_user_data_selector(gs);
 314 }
 315