osfmk/i386/commpage/commpage.c

   1 /*
   2  * Copyright (c) 2003 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 /*
  27  *      Here's what to do if you want to add a new routine to the comm page:
  28  *
  29  *              1. Add a definition for it's address in osfmk/ppc/cpu_capabilities.h,
  30  *                 being careful to reserve room for future expansion.
  31  *
  32  *              2. Write one or more versions of the routine, each with it's own
  33  *                 commpage_descriptor.  The tricky part is getting the "special",
  34  *                 "musthave", and "canthave" fields right, so that exactly one
  35  *                 version of the routine is selected for every machine.
  36  *                 The source files should be in osfmk/ppc/commpage/.
  37  *
  38  *              3. Add a ptr to your new commpage_descriptor(s) in the "routines"
  39  *                 array in commpage_populate().  Of course, you'll also have to
  40  *                 declare them "extern" in commpage_populate().
  41  *
  42  *              4. Write the code in Libc to use the new routine.
  43  */
  44
  45 #include <mach/mach_types.h>
  46 #include <mach/machine.h>
  47 #include <i386/machine_routines.h>
  48 #include <machine/cpu_capabilities.h>
  49 #include <machine/commpage.h>
  50 #include <machine/pmap.h>
  51 #include <vm/vm_kern.h>
  52 #include <mach/vm_map.h>
  53
  54 static  uintptr_t       next = 0;                       // next available byte in comm page
  55 static  int             cur_routine = 0;        // comm page address of "current" routine
  56 static  int             matched;                        // true if we've found a match for "current" routine
  57
  58 int     _cpu_capabilities = 0;          // define the capability vector
  59
  60 char    *commPagePtr = NULL;            // virtual address of comm page in kernel map
  61
  62 /* Allocate the commpage and add to the shared submap created by vm:
  63  *      1. allocate a page in the kernel map (RW)
  64  *      2. wire it down
  65  *      3. make a memory entry out of it
  66  *      4. map that entry into the shared comm region map (R-only)
  67  */
  68
  69 static  void*
  70 commpage_allocate( void )
  71 {
  72     extern  vm_map_t    com_region_map;             // the shared submap, set up in vm init
  73     vm_offset_t         kernel_addr;                // address of commpage in kernel map
  74     vm_offset_t         zero = 0;
  75     vm_size_t           size = _COMM_PAGE_AREA_LENGTH;
  76     ipc_port_t          handle;
  77
  78     if (com_region_map == NULL)
  79         panic("commpage map is null");
  80
  81     if (vm_allocate(kernel_map,&kernel_addr,_COMM_PAGE_AREA_LENGTH,VM_FLAGS_ANYWHERE))
  82         panic("cannot allocate commpage");
  83
  84     if (vm_map_wire(kernel_map,kernel_addr,kernel_addr+_COMM_PAGE_AREA_LENGTH,VM_PROT_DEFAULT,FALSE))
  85         panic("cannot wire commpage");
  86
  87     if (mach_make_memory_entry( kernel_map,         // target map
  88                                 &size,              // size
  89                                 kernel_addr,        // offset (address in kernel map)
  90                                 VM_PROT_DEFAULT,    // map it RW
  91                                 &handle,            // this is the object handle we get
  92                                 NULL ))             // parent_entry (what is this?)
  93         panic("cannot make entry for commpage");
  94
  95     if (vm_map_64(  com_region_map,                 // target map (shared submap)
  96                     &zero,                          // address (map into 1st page in submap)
  97                     _COMM_PAGE_AREA_LENGTH,         // size
  98                     0,                              // mask
  99                     VM_FLAGS_FIXED,                 // flags (it must be 1st page in submap)
 100                     handle,                         // port is the memory entry we just made
 101                     0,                              // offset (map 1st page in memory entry)
 102                     FALSE,                          // copy
 103                     VM_PROT_READ,                   // cur_protection (R-only in user map)
 104                     VM_PROT_READ,                   // max_protection
 105                     VM_INHERIT_SHARE ))             // inheritance
 106         panic("cannot map commpage");
 107
 108     ipc_port_release(handle);
 109
 110     return (void*) kernel_addr;                     // return address in kernel map
 111 }
 112
 113 /* Get address (in kernel map) of a commpage field. */
 114
 115 static  void*
 116 commpage_addr_of(
 117     int     addr_at_runtime )
 118 {
 119     return  (void*) ((uintptr_t)commPagePtr + addr_at_runtime - _COMM_PAGE_BASE_ADDRESS);
 120 }
 121
 122 /* Determine number of CPUs on this system.  We cannot rely on
 123  * machine_info.max_cpus this early in the boot.
 124  */
 125 static int
 126 commpage_cpus( void )
 127 {
 128         int cpus;
 129
 130         cpus = ml_get_max_cpus();                   // NB: this call can block
 131
 132         if (cpus == 0)
 133                 panic("commpage cpus==0");
 134         if (cpus > 0xFF)
 135                 cpus = 0xFF;
 136
 137         return cpus;
 138 }
 139
 140 /* Initialize kernel version of _cpu_capabilities vector (used by KEXTs.) */
 141
 142 static void
 143 commpage_init_cpu_capabilities( void )
 144 {
 145         int bits;
 146         int cpus;
 147         ml_cpu_info_t cpu_info;
 148
 149         bits = 0;
 150         ml_cpu_get_info(&cpu_info);
 151
 152         switch (cpu_info.vector_unit) {
 153                 case 5:
 154                         bits |= kHasPNI;
 155                         /* fall thru */
 156                 case 4:
 157                         bits |= kHasSSE2;
 158                         /* fall thru */
 159                 case 3:
 160                         bits |= kHasSSE;
 161                         /* fall thru */
 162                 case 2:
 163                         bits |= kHasMMX;
 164                 default:
 165                         break;
 166         }
 167         switch (cpu_info.cache_line_size) {
 168                 case 128:
 169                         bits |= kCache128;
 170                         break;
 171                 case 64:
 172                         bits |= kCache64;
 173                         break;
 174                 case 32:
 175                         bits |= kCache32;
 176                         break;
 177                 default:
 178                         break;
 179         }
 180         cpus = commpage_cpus();                 // how many CPUs do we have
 181
 182         if (cpus == 1)
 183                 bits |= kUP;
 184
 185         bits |= (cpus << kNumCPUsShift);
 186
 187         _cpu_capabilities = bits;               // set kernel version for use by drivers etc
 188 }
 189
 190 /* Copy data into commpage. */
 191
 192 static void
 193 commpage_stuff(
 194     int         address,
 195     void        *source,
 196     int         length  )
 197 {
 198     void        *dest = commpage_addr_of(address);
 199
 200     if ((uintptr_t)dest < next)
 201         panic("commpage overlap");
 202
 203     bcopy(source,dest,length);
 204
 205     next = ((uintptr_t)dest + length);
 206 }
 207
 208 /* Copy a routine into comm page if it matches running machine.
 209  */
 210 static void
 211 commpage_stuff_routine(
 212     commpage_descriptor *rd     )
 213 {
 214     int         must,cant;
 215
 216     if (rd->commpage_address != cur_routine) {
 217         if ((cur_routine!=0) && (matched==0))
 218             panic("commpage no match");
 219         cur_routine = rd->commpage_address;
 220         matched = 0;
 221     }
 222
 223     must = _cpu_capabilities & rd->musthave;
 224     cant = _cpu_capabilities & rd->canthave;
 225
 226     if ((must == rd->musthave) && (cant == 0)) {
 227         if (matched)
 228             panic("commpage duplicate matches");
 229         matched = 1;
 230
 231         commpage_stuff(rd->commpage_address,rd->code_address,rd->code_length);
 232         }
 233 }
 234
 235 /* Fill in commpage: called once, during kernel initialization, from the
 236  * startup thread before user-mode code is running.
 237  * See the top of this file for a list of what you have to do to add
 238  * a new routine to the commpage.
 239  */
 240
 241 void
 242 commpage_populate( void )
 243 {
 244         commpage_descriptor **rd;
 245         short   version = _COMM_PAGE_THIS_VERSION;
 246         void    *sig_addr;
 247
 248         extern char commpage_sigs_begin[];
 249         extern char commpage_sigs_end[];
 250
 251         extern commpage_descriptor commpage_mach_absolute_time;
 252         extern commpage_descriptor commpage_spin_lock_try_mp;
 253         extern commpage_descriptor commpage_spin_lock_try_up;
 254         extern commpage_descriptor commpage_spin_lock_mp;
 255         extern commpage_descriptor commpage_spin_lock_up;
 256         extern commpage_descriptor commpage_spin_unlock;
 257         extern commpage_descriptor commpage_pthread_getspecific;
 258         extern commpage_descriptor commpage_gettimeofday;
 259         extern commpage_descriptor commpage_sys_flush_dcache;
 260         extern commpage_descriptor commpage_sys_icache_invalidate;
 261         extern commpage_descriptor commpage_pthread_self;
 262         extern commpage_descriptor commpage_relinquish;
 263         extern commpage_descriptor commpage_bzero_scalar;
 264         extern commpage_descriptor commpage_bcopy_scalar;
 265
 266         static  commpage_descriptor *routines[] = {
 267                 &commpage_mach_absolute_time,
 268                 &commpage_spin_lock_try_mp,
 269                 &commpage_spin_lock_try_up,
 270                 &commpage_spin_lock_mp,
 271                 &commpage_spin_lock_up,
 272                 &commpage_spin_unlock,
 273                 &commpage_pthread_getspecific,
 274                 &commpage_gettimeofday,
 275                 &commpage_sys_flush_dcache,
 276                 &commpage_sys_icache_invalidate,
 277                 &commpage_pthread_self,
 278                 &commpage_relinquish,
 279                 &commpage_bzero_scalar,
 280                 &commpage_bcopy_scalar,
 281                 NULL
 282         };
 283
 284         commPagePtr = (char *)commpage_allocate();
 285
 286         commpage_init_cpu_capabilities();
 287
 288         /* Stuff in the constants.  We move things into the comm page in strictly
 289         * ascending order, so we can check for overlap and panic if so.
 290         */
 291
 292         commpage_stuff(_COMM_PAGE_VERSION,&version,sizeof(short));
 293         commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,
 294                 sizeof(int));
 295
 296         for( rd = routines; *rd != NULL ; rd++ )
 297                 commpage_stuff_routine(*rd);
 298
 299         if (!matched)
 300                 panic("commpage no match on last routine");
 301
 302         if (next > ((uintptr_t)commPagePtr + PAGE_SIZE))
 303                 panic("commpage overflow");
 304
 305 #define STUFF_SIG(addr, func) \
 306         extern char commpage_sig_ ## func [];                                   \
 307         sig_addr = (void *)(    (uintptr_t)_COMM_PAGE_BASE_ADDRESS +            \
 308                                 (uintptr_t)_COMM_PAGE_SIGS_OFFSET + 0x1000 +    \
 309                                 (uintptr_t)&commpage_sig_ ## func -             \
 310                                 (uintptr_t)&commpage_sigs_begin );              \
 311         commpage_stuff(addr + _COMM_PAGE_SIGS_OFFSET, &sig_addr, sizeof(void *));
 312
 313         STUFF_SIG(_COMM_PAGE_ABSOLUTE_TIME, mach_absolute_time);
 314         STUFF_SIG(_COMM_PAGE_SPINLOCK_TRY, spin_lock_try);
 315         STUFF_SIG(_COMM_PAGE_SPINLOCK_LOCK, spin_lock);
 316         STUFF_SIG(_COMM_PAGE_SPINLOCK_UNLOCK, spin_unlock);
 317         STUFF_SIG(_COMM_PAGE_PTHREAD_GETSPECIFIC, pthread_getspecific);
 318         STUFF_SIG(_COMM_PAGE_GETTIMEOFDAY, gettimeofday);
 319         STUFF_SIG(_COMM_PAGE_FLUSH_DCACHE, sys_dcache_flush);
 320         STUFF_SIG(_COMM_PAGE_FLUSH_ICACHE, sys_icache_invalidate);
 321         STUFF_SIG(_COMM_PAGE_PTHREAD_SELF, pthread_self);
 322         STUFF_SIG(_COMM_PAGE_BZERO, bzero);
 323         STUFF_SIG(_COMM_PAGE_BCOPY, bcopy);
 324         STUFF_SIG(_COMM_PAGE_MEMCPY, memmove);
 325
 326         commpage_stuff(_COMM_PAGE_BASE_ADDRESS + _COMM_PAGE_SIGS_OFFSET + 0x1000, &commpage_sigs_begin,
 327                         (uintptr_t)&commpage_sigs_end - (uintptr_t)&commpage_sigs_begin);
 328 }