osfmk/i386/mp_desc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  * @OSF_COPYRIGHT@
  30  */
  31 /*
  32  * Mach Operating System
  33  * Copyright (c) 1991,1990 Carnegie Mellon University
  34  * All Rights Reserved.
  35  *
  36  * Permission to use, copy, modify and distribute this software and its
  37  * documentation is hereby granted, provided that both the copyright
  38  * notice and this permission notice appear in all copies of the
  39  * software, derivative works or modified versions, and any portions
  40  * thereof, and that both notices appear in supporting documentation.
  41  *
  42  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  43  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  44  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  45  *
  46  * Carnegie Mellon requests users of this software to return to
  47  *
  48  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  49  *  School of Computer Science
  50  *  Carnegie Mellon University
  51  *  Pittsburgh PA 15213-3890
  52  *
  53  * any improvements or extensions that they make and grant Carnegie Mellon
  54  * the rights to redistribute these changes.
  55  */
  56
  57 /*
  58  */
  59
  60
  61 #include <kern/cpu_number.h>
  62 #include <kern/kalloc.h>
  63 #include <kern/cpu_data.h>
  64 #include <mach/machine.h>
  65 #include <vm/vm_kern.h>
  66
  67 #include <i386/mp_desc.h>
  68 #include <i386/lock.h>
  69 #include <i386/misc_protos.h>
  70 #include <i386/mp.h>
  71 #include <i386/pmap.h>
  72
  73 #include <kern/misc_protos.h>
  74
  75 #include <mach_kdb.h>
  76
  77 /*
  78  * The i386 needs an interrupt stack to keep the PCB stack from being
  79  * overrun by interrupts.  All interrupt stacks MUST lie at lower addresses
  80  * than any thread`s kernel stack.
  81  */
  82
  83 /*
  84  * First cpu`s interrupt stack.
  85  */
  86 extern char             intstack[];     /* bottom */
  87 extern char             eintstack[];    /* top */
  88
  89 /*
  90  * Per-cpu data area pointers.
  91  * The master cpu (cpu 0) has its data area statically allocated;
  92  * others are allocated dynamically and this array is updated at runtime.
  93  */
  94 cpu_data_t      cpu_data_master;
  95 cpu_data_t      *cpu_data_ptr[MAX_CPUS] = { [0] &cpu_data_master };
  96
  97 decl_simple_lock_data(,cpu_lock);       /* protects real_ncpus */
  98 unsigned int    real_ncpus = 1;
  99 unsigned int    max_ncpus = MAX_CPUS;
 100
 101 /*
 102  * Multiprocessor i386/i486 systems use a separate copy of the
 103  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
 104  * are separate to avoid lock contention: the i386 uses locked
 105  * memory cycles to access the descriptor tables.  The TSS is
 106  * separate since each processor needs its own kernel stack,
 107  * and since using a TSS marks it busy.
 108  */
 109
 110 /*
 111  * Allocate and initialize the per-processor descriptor tables.
 112  */
 113
 114 struct fake_descriptor ldt_desc_pattern = {
 115         (unsigned int) 0,
 116         LDTSZ * sizeof(struct fake_descriptor) - 1,
 117         0,
 118         ACC_P|ACC_PL_K|ACC_LDT
 119 };
 120 struct fake_descriptor tss_desc_pattern = {
 121         (unsigned int) 0,
 122         sizeof(struct i386_tss),
 123         0,
 124         ACC_P|ACC_PL_K|ACC_TSS
 125 };
 126
 127 struct fake_descriptor cpudata_desc_pattern = {
 128         (unsigned int) 0,
 129         sizeof(cpu_data_t)-1,
 130         SZ_32,
 131         ACC_P|ACC_PL_K|ACC_DATA_W
 132 };
 133
 134 void
 135 mp_desc_init(
 136         cpu_data_t      *cdp,
 137         boolean_t       is_boot_cpu)
 138 {
 139         struct mp_desc_table    *mpt = cdp->cpu_desc_tablep;
 140         cpu_desc_index_t        *cdt = &cdp->cpu_desc_index;
 141
 142         if (is_boot_cpu) {
 143             /*
 144              * Master CPU uses the tables built at boot time.
 145              * Just set the TSS and GDT pointers.
 146              */
 147             cdt->cdi_ktss = &ktss;
 148 #if     MACH_KDB
 149             cdt->cdi_dbtss = &dbtss;
 150 #endif  /* MACH_KDB */
 151             cdt->cdi_gdt = gdt;
 152             cdt->cdi_idt = idt;
 153             cdt->cdi_ldt = ldt;
 154
 155         } else {
 156
 157             cdt->cdi_ktss = &mpt->ktss;
 158             cdt->cdi_gdt = mpt->gdt;
 159             cdt->cdi_idt = mpt->idt;
 160             cdt->cdi_ldt = mpt->ldt;
 161
 162             /*
 163              * Copy the tables
 164              */
 165             bcopy((char *)idt,
 166                   (char *)mpt->idt,
 167                   sizeof(idt));
 168             bcopy((char *)gdt,
 169                   (char *)mpt->gdt,
 170                   sizeof(gdt));
 171             bcopy((char *)ldt,
 172                   (char *)mpt->ldt,
 173                   sizeof(ldt));
 174             bzero((char *)&mpt->ktss,
 175                   sizeof(struct i386_tss));
 176
 177 #if     MACH_KDB
 178             cdt->cdi_dbtss = &dbtss;
 179             bcopy((char *)&dbtss,
 180                   (char *)&mpt->dbtss,
 181                   sizeof(struct i386_tss));
 182 #endif  /* MACH_KDB */
 183
 184             /*
 185              * Fix up the entries in the GDT to point to
 186              * this LDT and this TSS.
 187              */
 188             mpt->gdt[sel_idx(KERNEL_LDT)] = ldt_desc_pattern;
 189             mpt->gdt[sel_idx(KERNEL_LDT)].offset = (vm_offset_t) mpt->ldt;
 190             fix_desc(&mpt->gdt[sel_idx(KERNEL_LDT)], 1);
 191
 192             mpt->gdt[sel_idx(KERNEL_TSS)] = tss_desc_pattern;
 193             mpt->gdt[sel_idx(KERNEL_TSS)].offset = (vm_offset_t) &mpt->ktss;
 194             fix_desc(&mpt->gdt[sel_idx(KERNEL_TSS)], 1);
 195
 196             mpt->gdt[sel_idx(CPU_DATA_GS)] = cpudata_desc_pattern;
 197             mpt->gdt[sel_idx(CPU_DATA_GS)].offset = (vm_offset_t) cdp;
 198             fix_desc(&mpt->gdt[sel_idx(CPU_DATA_GS)], 1);
 199
 200 #if     MACH_KDB
 201             mpt->gdt[sel_idx(DEBUG_TSS)] = tss_desc_pattern;
 202             mpt->gdt[sel_idx(DEBUG_TSS)].offset = (vm_offset_t) &mpt->dbtss;
 203             fix_desc(&mpt->gdt[sel_idx(DEBUG_TSS)], 1);
 204
 205             mpt->dbtss.esp0 = (int)(db_task_stack_store +
 206                     (INTSTACK_SIZE * (cpu + 1)) - sizeof (natural_t));
 207             mpt->dbtss.esp = mpt->dbtss.esp0;
 208             mpt->dbtss.eip = (int)&db_task_start;
 209 #endif  /* MACH_KDB */
 210
 211             mpt->ktss.ss0 = KERNEL_DS;
 212             mpt->ktss.io_bit_map_offset = 0x0FFF;       /* no IO bitmap */
 213         }
 214 }
 215
 216 cpu_data_t *
 217 cpu_data_alloc(boolean_t is_boot_cpu)
 218 {
 219         int             ret;
 220         cpu_data_t      *cdp;
 221
 222         if (is_boot_cpu) {
 223                 assert(real_ncpus == 1);
 224                 simple_lock_init(&cpu_lock, 0);
 225                 cdp = &cpu_data_master;
 226                 if (cdp->cpu_processor == NULL) {
 227                         cdp->cpu_processor = cpu_processor_alloc(TRUE);
 228                         cdp->cpu_pmap = pmap_cpu_alloc(TRUE);
 229                         cdp->cpu_this = cdp;
 230                         cdp->cpu_int_stack_top = (vm_offset_t) eintstack;
 231                         mp_desc_init(cdp, TRUE);
 232                 }
 233                 return cdp;
 234         }
 235
 236         /* Check count before making allocations */
 237         if (real_ncpus >= max_ncpus)
 238                 return NULL;
 239
 240         /*
 241          * Allocate per-cpu data:
 242          */
 243         ret = kmem_alloc(kernel_map,
 244                          (vm_offset_t *) &cdp, sizeof(cpu_data_t));
 245         if (ret != KERN_SUCCESS) {
 246                 printf("cpu_data_alloc() failed, ret=%d\n", ret);
 247                 goto abort;
 248         }
 249         bzero((void*) cdp, sizeof(cpu_data_t));
 250         cdp->cpu_this = cdp;
 251
 252         /*
 253          * Allocate interrupt stack:
 254          */
 255         ret = kmem_alloc(kernel_map,
 256                          (vm_offset_t *) &cdp->cpu_int_stack_top,
 257                          INTSTACK_SIZE);
 258         if (ret != KERN_SUCCESS) {
 259                 printf("cpu_data_alloc() int stack failed, ret=%d\n", ret);
 260                 goto abort;
 261         }
 262         bzero((void*) cdp->cpu_int_stack_top, INTSTACK_SIZE);
 263         cdp->cpu_int_stack_top += INTSTACK_SIZE;
 264
 265         /*
 266          * Allocate descriptor table:
 267          */
 268         ret = kmem_alloc(kernel_map,
 269                          (vm_offset_t *) &cdp->cpu_desc_tablep,
 270                          sizeof(struct mp_desc_table));
 271         if (ret != KERN_SUCCESS) {
 272                 printf("cpu_data_alloc() desc_table failed, ret=%d\n", ret);
 273                 goto abort;
 274         }
 275
 276         simple_lock(&cpu_lock);
 277         if (real_ncpus >= max_ncpus) {
 278                 simple_unlock(&cpu_lock);
 279                 goto abort;
 280         }
 281         cpu_data_ptr[real_ncpus] = cdp;
 282         cdp->cpu_number = real_ncpus;
 283         real_ncpus++;
 284         simple_unlock(&cpu_lock);
 285
 286         kprintf("cpu_data_alloc(%d) 0x%x desc_table: 0x%x "
 287                 "int_stack: 0x%x-0x%x\n",
 288                 cdp->cpu_number, cdp, cdp->cpu_desc_tablep,
 289                 cdp->cpu_int_stack_top - INTSTACK_SIZE, cdp->cpu_int_stack_top);
 290
 291         return cdp;
 292
 293 abort:
 294         if (cdp) {
 295                 if (cdp->cpu_desc_tablep)
 296                         kfree((void *) cdp->cpu_desc_tablep,
 297                                 sizeof(*cdp->cpu_desc_tablep));
 298                 if (cdp->cpu_int_stack_top)
 299                         kfree((void *) (cdp->cpu_int_stack_top - INTSTACK_SIZE),
 300                                 INTSTACK_SIZE);
 301                 kfree((void *) cdp, sizeof(*cdp));
 302         }
 303         return NULL;
 304 }
 305
 306 boolean_t
 307 valid_user_segment_selectors(uint16_t cs,
 308                              uint16_t ss,
 309                              uint16_t ds,
 310                              uint16_t es,
 311                              uint16_t fs,
 312                              uint16_t gs)
 313 {
 314         return valid_user_code_selector(cs)  &&
 315                valid_user_stack_selector(ss) &&
 316                valid_user_data_selector(ds)  &&
 317                valid_user_data_selector(es)  &&
 318                valid_user_data_selector(fs)  &&
 319                valid_user_data_selector(gs);
 320 }
 321