osfmk/i386/mp_desc.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /*
  26  * @OSF_COPYRIGHT@
  27  */
  28 /*
  29  * Mach Operating System
  30  * Copyright (c) 1991,1990 Carnegie Mellon University
  31  * All Rights Reserved.
  32  *
  33  * Permission to use, copy, modify and distribute this software and its
  34  * documentation is hereby granted, provided that both the copyright
  35  * notice and this permission notice appear in all copies of the
  36  * software, derivative works or modified versions, and any portions
  37  * thereof, and that both notices appear in supporting documentation.
  38  *
  39  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
  40  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
  41  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
  42  *
  43  * Carnegie Mellon requests users of this software to return to
  44  *
  45  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
  46  *  School of Computer Science
  47  *  Carnegie Mellon University
  48  *  Pittsburgh PA 15213-3890
  49  *
  50  * any improvements or extensions that they make and grant Carnegie Mellon
  51  * the rights to redistribute these changes.
  52  */
  53
  54 /*
  55  */
  56
  57 #include <cpus.h>
  58
  59 #if     NCPUS > 1
  60
  61 #include <kern/cpu_number.h>
  62 #include <kern/cpu_data.h>
  63 #include <mach/machine.h>
  64 #include <vm/vm_kern.h>
  65
  66 #include <i386/mp_desc.h>
  67 #include <i386/lock.h>
  68 #include <i386/misc_protos.h>
  69
  70 #include <kern/misc_protos.h>
  71
  72 #include <mach_kdb.h>
  73
  74 /*
  75  * The i386 needs an interrupt stack to keep the PCB stack from being
  76  * overrun by interrupts.  All interrupt stacks MUST lie at lower addresses
  77  * than any thread`s kernel stack.
  78  */
  79
  80 /*
  81  * Addresses of bottom and top of interrupt stacks.
  82  */
  83 vm_offset_t     interrupt_stack[NCPUS];
  84 vm_offset_t     int_stack_top[NCPUS];
  85
  86 /*
  87  * Barrier address.
  88  */
  89 vm_offset_t     int_stack_high;
  90
  91 /*
  92  * First cpu`s interrupt stack.
  93  */
  94 extern char             intstack[];     /* bottom */
  95 extern char             eintstack[];    /* top */
  96
  97 /*
  98  * We allocate interrupt stacks from physical memory.
  99  */
 100 extern
 101 vm_offset_t     avail_start;
 102
 103 /*
 104  * Multiprocessor i386/i486 systems use a separate copy of the
 105  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
 106  * are separate to avoid lock contention: the i386 uses locked
 107  * memory cycles to access the descriptor tables.  The TSS is
 108  * separate since each processor needs its own kernel stack,
 109  * and since using a TSS marks it busy.
 110  */
 111
 112 /*
 113  * Allocated descriptor tables.
 114  */
 115 struct mp_desc_table    *mp_desc_table[NCPUS] = { 0 };
 116
 117 /*
 118  * Pointer to TSS for access in load_context.
 119  */
 120 struct i386_tss         *mp_ktss[NCPUS] = { 0 };
 121
 122 #if     MACH_KDB
 123 /*
 124  * Pointer to TSS for debugger use.
 125  */
 126 struct i386_tss         *mp_dbtss[NCPUS] = { 0 };
 127 #endif  /* MACH_KDB */
 128
 129 /*
 130  * Pointer to GDT to reset the KTSS busy bit.
 131  */
 132 struct fake_descriptor  *mp_gdt[NCPUS] = { 0 };
 133 struct fake_descriptor  *mp_idt[NCPUS] = { 0 };
 134
 135 /*
 136  * Allocate and initialize the per-processor descriptor tables.
 137  */
 138
 139 struct fake_descriptor ldt_desc_pattern = {
 140         (unsigned int) 0,
 141         LDTSZ * sizeof(struct fake_descriptor) - 1,
 142         0,
 143         ACC_P|ACC_PL_K|ACC_LDT
 144 };
 145 struct fake_descriptor tss_desc_pattern = {
 146         (unsigned int) 0,
 147         sizeof(struct i386_tss),
 148         0,
 149         ACC_P|ACC_PL_K|ACC_TSS
 150 };
 151
 152 struct fake_descriptor cpudata_desc_pattern = {
 153         (unsigned int) 0,
 154         sizeof(cpu_data_t)-1,
 155         SZ_32,
 156         ACC_P|ACC_PL_K|ACC_DATA_W
 157 };
 158
 159 struct mp_desc_table *
 160 mp_desc_init(
 161         int     mycpu)
 162 {
 163         register struct mp_desc_table *mpt;
 164
 165         if (mycpu == master_cpu) {
 166             /*
 167              * Master CPU uses the tables built at boot time.
 168              * Just set the TSS and GDT pointers.
 169              */
 170             mp_ktss[mycpu] = &ktss;
 171 #if     MACH_KDB
 172             mp_dbtss[mycpu] = &dbtss;
 173 #endif  /* MACH_KDB */
 174             mp_gdt[mycpu] = gdt;
 175             mp_idt[mycpu] = idt;
 176             return 0;
 177         }
 178         else {
 179             mpt = mp_desc_table[mycpu];
 180             mp_ktss[mycpu] = &mpt->ktss;
 181             mp_gdt[mycpu] = mpt->gdt;
 182             mp_idt[mycpu] = mpt->idt;
 183
 184             /*
 185              * Copy the tables
 186              */
 187             bcopy((char *)idt,
 188                   (char *)mpt->idt,
 189                   sizeof(idt));
 190             bcopy((char *)gdt,
 191                   (char *)mpt->gdt,
 192                   sizeof(gdt));
 193             bcopy((char *)ldt,
 194                   (char *)mpt->ldt,
 195                   sizeof(ldt));
 196             bzero((char *)&mpt->ktss,
 197                   sizeof(struct i386_tss));
 198             bzero((char *)&cpu_data[mycpu],
 199                   sizeof(cpu_data_t));
 200 #if     MACH_KDB
 201             mp_dbtss[mycpu] = &mpt->dbtss;
 202             bcopy((char *)&dbtss,
 203                   (char *)&mpt->dbtss,
 204                   sizeof(struct i386_tss));
 205 #endif  /* MACH_KDB */
 206
 207             /*
 208              * Fix up the entries in the GDT to point to
 209              * this LDT and this TSS.
 210              */
 211             mpt->gdt[sel_idx(KERNEL_LDT)] = ldt_desc_pattern;
 212             mpt->gdt[sel_idx(KERNEL_LDT)].offset =
 213                 LINEAR_KERNEL_ADDRESS + (unsigned int) mpt->ldt;
 214             fix_desc(&mpt->gdt[sel_idx(KERNEL_LDT)], 1);
 215
 216             mpt->gdt[sel_idx(KERNEL_TSS)] = tss_desc_pattern;
 217             mpt->gdt[sel_idx(KERNEL_TSS)].offset =
 218                 LINEAR_KERNEL_ADDRESS + (unsigned int) &mpt->ktss;
 219             fix_desc(&mpt->gdt[sel_idx(KERNEL_TSS)], 1);
 220
 221             mpt->gdt[sel_idx(CPU_DATA)] = cpudata_desc_pattern;
 222             mpt->gdt[sel_idx(CPU_DATA)].offset =
 223                 LINEAR_KERNEL_ADDRESS + (unsigned int) &cpu_data[mycpu];
 224             fix_desc(&mpt->gdt[sel_idx(CPU_DATA)], 1);
 225
 226 #if     MACH_KDB
 227             mpt->gdt[sel_idx(DEBUG_TSS)] = tss_desc_pattern;
 228             mpt->gdt[sel_idx(DEBUG_TSS)].offset =
 229                     LINEAR_KERNEL_ADDRESS + (unsigned int) &mpt->dbtss;
 230             fix_desc(&mpt->gdt[sel_idx(DEBUG_TSS)], 1);
 231
 232             mpt->dbtss.esp0 = (int)(db_task_stack_store +
 233                     (INTSTACK_SIZE * (mycpu + 1)) - sizeof (natural_t));
 234             mpt->dbtss.esp = mpt->dbtss.esp0;
 235             mpt->dbtss.eip = (int)&db_task_start;
 236 #endif  /* MACH_KDB */
 237
 238             mpt->ktss.ss0 = KERNEL_DS;
 239             mpt->ktss.io_bit_map_offset = 0x0FFF;       /* no IO bitmap */
 240
 241             return mpt;
 242         }
 243 }
 244
 245 /*
 246  * Called after all CPUs have been found, but before the VM system
 247  * is running.  The machine array must show which CPUs exist.
 248  */
 249 void
 250 interrupt_stack_alloc(void)
 251 {
 252         register int            i;
 253         int                     cpu_count;
 254         vm_offset_t             stack_start;
 255         struct mp_desc_table    *mpt;
 256
 257         /*
 258          * Count the number of CPUs.
 259          */
 260         cpu_count = 0;
 261         for (i = 0; i < NCPUS; i++)
 262             if (machine_slot[i].is_cpu)
 263                 cpu_count++;
 264
 265         /*
 266          * Allocate an interrupt stack for each CPU except for
 267          * the master CPU (which uses the bootstrap stack)
 268          */
 269         stack_start = phystokv(avail_start);
 270         avail_start = round_page(avail_start + INTSTACK_SIZE*(cpu_count-1));
 271         bzero((char *)stack_start, INTSTACK_SIZE*(cpu_count-1));
 272
 273         /*
 274          * Set up pointers to the top of the interrupt stack.
 275          */
 276         for (i = 0; i < NCPUS; i++) {
 277             if (i == master_cpu) {
 278                 interrupt_stack[i] = (vm_offset_t) intstack;
 279                 int_stack_top[i]   = (vm_offset_t) eintstack;
 280             }
 281             else if (machine_slot[i].is_cpu) {
 282                 interrupt_stack[i] = stack_start;
 283                 int_stack_top[i]   = stack_start + INTSTACK_SIZE;
 284
 285                 stack_start += INTSTACK_SIZE;
 286             }
 287         }
 288
 289         /*
 290          * Allocate descriptor tables for each CPU except for
 291          * the master CPU (which already has them initialized)
 292          */
 293
 294         mpt = (struct mp_desc_table *) phystokv(avail_start);
 295         avail_start = round_page((vm_offset_t)avail_start +
 296                                  sizeof(struct mp_desc_table)*(cpu_count-1));
 297         for (i = 0; i < NCPUS; i++)
 298             if (i != master_cpu)
 299                 mp_desc_table[i] = mpt++;
 300
 301
 302         /*
 303          * Set up the barrier address.  All thread stacks MUST
 304          * be above this address.
 305          */
 306         /*
 307          * intstack is at higher addess than stack_start for AT mps
 308          * so int_stack_high must point at eintstack.
 309          * XXX
 310          * But what happens if a kernel stack gets allocated below
 311          * 1 Meg ? Probably never happens, there is only 640 K available
 312          * There.
 313          */
 314         int_stack_high = (vm_offset_t) eintstack;
 315 }
 316
 317 #endif /* NCPUS > 1 */