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 #include <cpus.h>
  55
  56 #if     NCPUS > 1
  57
  58 #include <kern/cpu_number.h>
  59 #include <kern/cpu_data.h>
  60 #include <mach/machine.h>
  61 #include <vm/vm_kern.h>
  62
  63 #include <i386/mp_desc.h>
  64 #include <i386/lock.h>
  65 #include <i386/misc_protos.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  * Addresses of bottom and top of interrupt stacks.
  79  */
  80 vm_offset_t     interrupt_stack[NCPUS];
  81 vm_offset_t     int_stack_top[NCPUS];
  82
  83 /*
  84  * Barrier address.
  85  */
  86 vm_offset_t     int_stack_high;
  87
  88 /*
  89  * First cpu`s interrupt stack.
  90  */
  91 extern char             intstack[];     /* bottom */
  92 extern char             eintstack[];    /* top */
  93
  94 /*
  95  * We allocate interrupt stacks from physical memory.
  96  */
  97 extern
  98 vm_offset_t     avail_start;
  99
 100 /*
 101  * Multiprocessor i386/i486 systems use a separate copy of the
 102  * GDT, IDT, LDT, and kernel TSS per processor.  The first three
 103  * are separate to avoid lock contention: the i386 uses locked
 104  * memory cycles to access the descriptor tables.  The TSS is
 105  * separate since each processor needs its own kernel stack,
 106  * and since using a TSS marks it busy.
 107  */
 108
 109 /*
 110  * Allocated descriptor tables.
 111  */
 112 struct mp_desc_table    *mp_desc_table[NCPUS] = { 0 };
 113
 114 /*
 115  * Pointer to TSS for access in load_context.
 116  */
 117 struct i386_tss         *mp_ktss[NCPUS] = { 0 };
 118
 119 #if     MACH_KDB
 120 /*
 121  * Pointer to TSS for debugger use.
 122  */
 123 struct i386_tss         *mp_dbtss[NCPUS] = { 0 };
 124 #endif  /* MACH_KDB */
 125
 126 /*
 127  * Pointer to GDT to reset the KTSS busy bit.
 128  */
 129 struct fake_descriptor  *mp_gdt[NCPUS] = { 0 };
 130 struct fake_descriptor  *mp_idt[NCPUS] = { 0 };
 131
 132 /*
 133  * Allocate and initialize the per-processor descriptor tables.
 134  */
 135
 136 struct fake_descriptor ldt_desc_pattern = {
 137         (unsigned int) 0,
 138         LDTSZ * sizeof(struct fake_descriptor) - 1,
 139         0,
 140         ACC_P|ACC_PL_K|ACC_LDT
 141 };
 142 struct fake_descriptor tss_desc_pattern = {
 143         (unsigned int) 0,
 144         sizeof(struct i386_tss),
 145         0,
 146         ACC_P|ACC_PL_K|ACC_TSS
 147 };
 148
 149 struct fake_descriptor cpudata_desc_pattern = {
 150         (unsigned int) 0,
 151         sizeof(cpu_data_t)-1,
 152         SZ_32,
 153         ACC_P|ACC_PL_K|ACC_DATA_W
 154 };
 155
 156 struct mp_desc_table *
 157 mp_desc_init(
 158         int     mycpu)
 159 {
 160         register struct mp_desc_table *mpt;
 161
 162         if (mycpu == master_cpu) {
 163             /*
 164              * Master CPU uses the tables built at boot time.
 165              * Just set the TSS and GDT pointers.
 166              */
 167             mp_ktss[mycpu] = &ktss;
 168 #if     MACH_KDB
 169             mp_dbtss[mycpu] = &dbtss;
 170 #endif  /* MACH_KDB */
 171             mp_gdt[mycpu] = gdt;
 172             mp_idt[mycpu] = idt;
 173             return 0;
 174         }
 175         else {
 176             mpt = mp_desc_table[mycpu];
 177             mp_ktss[mycpu] = &mpt->ktss;
 178             mp_gdt[mycpu] = mpt->gdt;
 179             mp_idt[mycpu] = mpt->idt;
 180
 181             /*
 182              * Copy the tables
 183              */
 184             bcopy((char *)idt,
 185                   (char *)mpt->idt,
 186                   sizeof(idt));
 187             bcopy((char *)gdt,
 188                   (char *)mpt->gdt,
 189                   sizeof(gdt));
 190             bcopy((char *)ldt,
 191                   (char *)mpt->ldt,
 192                   sizeof(ldt));
 193             bzero((char *)&mpt->ktss,
 194                   sizeof(struct i386_tss));
 195             bzero((char *)&cpu_data[mycpu],
 196                   sizeof(cpu_data_t));
 197 #if     MACH_KDB
 198             mp_dbtss[mycpu] = &mpt->dbtss;
 199             bcopy((char *)&dbtss,
 200                   (char *)&mpt->dbtss,
 201                   sizeof(struct i386_tss));
 202 #endif  /* MACH_KDB */
 203
 204             /*
 205              * Fix up the entries in the GDT to point to
 206              * this LDT and this TSS.
 207              */
 208             mpt->gdt[sel_idx(KERNEL_LDT)] = ldt_desc_pattern;
 209             mpt->gdt[sel_idx(KERNEL_LDT)].offset =
 210                 LINEAR_KERNEL_ADDRESS + (unsigned int) mpt->ldt;
 211             fix_desc(&mpt->gdt[sel_idx(KERNEL_LDT)], 1);
 212
 213             mpt->gdt[sel_idx(KERNEL_TSS)] = tss_desc_pattern;
 214             mpt->gdt[sel_idx(KERNEL_TSS)].offset =
 215                 LINEAR_KERNEL_ADDRESS + (unsigned int) &mpt->ktss;
 216             fix_desc(&mpt->gdt[sel_idx(KERNEL_TSS)], 1);
 217
 218             mpt->gdt[sel_idx(CPU_DATA)] = cpudata_desc_pattern;
 219             mpt->gdt[sel_idx(CPU_DATA)].offset =
 220                 LINEAR_KERNEL_ADDRESS + (unsigned int) &cpu_data[mycpu];
 221             fix_desc(&mpt->gdt[sel_idx(CPU_DATA)], 1);
 222
 223 #if     MACH_KDB
 224             mpt->gdt[sel_idx(DEBUG_TSS)] = tss_desc_pattern;
 225             mpt->gdt[sel_idx(DEBUG_TSS)].offset =
 226                     LINEAR_KERNEL_ADDRESS + (unsigned int) &mpt->dbtss;
 227             fix_desc(&mpt->gdt[sel_idx(DEBUG_TSS)], 1);
 228
 229             mpt->dbtss.esp0 = (int)(db_task_stack_store +
 230                     (INTSTACK_SIZE * (mycpu + 1)) - sizeof (natural_t));
 231             mpt->dbtss.esp = mpt->dbtss.esp0;
 232             mpt->dbtss.eip = (int)&db_task_start;
 233 #endif  /* MACH_KDB */
 234
 235             mpt->ktss.ss0 = KERNEL_DS;
 236             mpt->ktss.io_bit_map_offset = 0x0FFF;       /* no IO bitmap */
 237
 238             return mpt;
 239         }
 240 }
 241
 242 /*
 243  * Called after all CPUs have been found, but before the VM system
 244  * is running.  The machine array must show which CPUs exist.
 245  */
 246 void
 247 interrupt_stack_alloc(void)
 248 {
 249         register int            i;
 250         int                     cpu_count;
 251         vm_offset_t             stack_start;
 252         struct mp_desc_table    *mpt;
 253
 254         /*
 255          * Count the number of CPUs.
 256          */
 257         cpu_count = 0;
 258         for (i = 0; i < NCPUS; i++)
 259             if (machine_slot[i].is_cpu)
 260                 cpu_count++;
 261
 262         /*
 263          * Allocate an interrupt stack for each CPU except for
 264          * the master CPU (which uses the bootstrap stack)
 265          */
 266         stack_start = phystokv(avail_start);
 267         avail_start = round_page(avail_start + INTSTACK_SIZE*(cpu_count-1));
 268         bzero((char *)stack_start, INTSTACK_SIZE*(cpu_count-1));
 269
 270         /*
 271          * Set up pointers to the top of the interrupt stack.
 272          */
 273         for (i = 0; i < NCPUS; i++) {
 274             if (i == master_cpu) {
 275                 interrupt_stack[i] = (vm_offset_t) intstack;
 276                 int_stack_top[i]   = (vm_offset_t) eintstack;
 277             }
 278             else if (machine_slot[i].is_cpu) {
 279                 interrupt_stack[i] = stack_start;
 280                 int_stack_top[i]   = stack_start + INTSTACK_SIZE;
 281
 282                 stack_start += INTSTACK_SIZE;
 283             }
 284         }
 285
 286         /*
 287          * Allocate descriptor tables for each CPU except for
 288          * the master CPU (which already has them initialized)
 289          */
 290
 291         mpt = (struct mp_desc_table *) phystokv(avail_start);
 292         avail_start = round_page((vm_offset_t)avail_start +
 293                                  sizeof(struct mp_desc_table)*(cpu_count-1));
 294         for (i = 0; i < NCPUS; i++)
 295             if (i != master_cpu)
 296                 mp_desc_table[i] = mpt++;
 297
 298
 299         /*
 300          * Set up the barrier address.  All thread stacks MUST
 301          * be above this address.
 302          */
 303         /*
 304          * intstack is at higher addess than stack_start for AT mps
 305          * so int_stack_high must point at eintstack.
 306          * XXX
 307          * But what happens if a kernel stack gets allocated below
 308          * 1 Meg ? Probably never happens, there is only 640 K available
 309          * There.
 310          */
 311         int_stack_high = (vm_offset_t) eintstack;
 312 }
 313
 314 #endif /* NCPUS > 1 */