osfmk/ppc/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 <ppc/exception.h>
  48 #include <ppc/machine_routines.h>
  49 #include <machine/cpu_capabilities.h>
  50 #include <machine/commpage.h>
  51 #include <machine/pmap.h>
  52 #include <vm/vm_kern.h>
  53 #include <mach/vm_map.h>
  54
  55 static  char    *next = NULL;                   // next available byte in comm page
  56 static  int             cur_routine = 0;                // comm page address of "current" routine
  57 static  int             matched;                                // true if we've found a match for "current" routine
  58
  59 int             _cpu_capabilities = 0;                  // define the capability vector
  60
  61 char    *commPagePtr = NULL;                    // virtual address of comm page in kernel map
  62
  63
  64 /* Allocate the commpages and add to the shared submap created by vm:
  65  *      1. allocate pages in the kernel map (RW)
  66  *      2. wire them down
  67  *      3. make a memory entry out of them
  68  *      4. map that entry into the shared comm region map (R-only)
  69  */
  70 static  void*
  71 commpage_allocate( void )
  72 {
  73     extern      vm_map_t        com_region_map;                         // the shared submap, set up in vm init
  74     vm_offset_t                 kernel_addr;                            // address of commpage in kernel map
  75     vm_offset_t                 zero = 0;
  76     vm_size_t                   size = _COMM_PAGE_AREA_USED;    // size actually populated
  77     ipc_port_t                  handle;
  78
  79     if (com_region_map == NULL)
  80         panic("commpage map is null");
  81
  82     if (vm_allocate(kernel_map,&kernel_addr,_COMM_PAGE_AREA_USED,VM_FLAGS_ANYWHERE))
  83         panic("cannot allocate commpage");
  84
  85     if (vm_map_wire(kernel_map,kernel_addr,kernel_addr+_COMM_PAGE_AREA_USED,VM_PROT_DEFAULT,FALSE))
  86         panic("cannot wire commpage");
  87
  88     if (mach_make_memory_entry( kernel_map,                     // target map
  89                                 &size,                          // size
  90                                 kernel_addr,            // offset (address in kernel map)
  91                                 VM_PROT_DEFAULT,        // map it RW
  92                                 &handle,                        // this is the object handle we get
  93                                 NULL ))                         // parent_entry
  94         panic("cannot make entry for commpage");
  95
  96     if (vm_map_64(      com_region_map,                                 // target map (shared submap)
  97                     &zero,                                                      // address (map into 1st page in submap)
  98                     _COMM_PAGE_AREA_USED,                       // size
  99                     0,                                                          // mask
 100                     VM_FLAGS_FIXED,                                     // flags (it must be 1st page in submap)
 101                     handle,                                                     // port is the memory entry we just made
 102                     0,                                                          // offset (map 1st page in memory entry)
 103                     FALSE,                                                      // copy
 104                     VM_PROT_READ,                                       // cur_protection (R-only in user map)
 105                     VM_PROT_READ,                                       // max_protection
 106                     VM_INHERIT_SHARE ))                         // inheritance
 107         panic("cannot map commpage");
 108
 109     ipc_port_release(handle);
 110
 111     return (void*) kernel_addr;                                         // return address in kernel map
 112 }
 113
 114
 115 /* Get address (in kernel map) of a commpage field. */
 116
 117 static  void*
 118 commpage_addr_of(
 119     int         addr_at_runtime )
 120 {
 121     return      (void*) (commPagePtr + addr_at_runtime - _COMM_PAGE_BASE_ADDRESS);
 122 }
 123
 124
 125 /* Determine number of CPUs on this system.  We cannot rely on
 126  * machine_info.max_cpus this early in the boot.
 127  */
 128 static int
 129 commpage_cpus( void )
 130 {
 131     int         cpus;
 132
 133     cpus = ml_get_max_cpus();                   // NB: this call can block
 134
 135     if (cpus == 0)
 136         panic("commpage cpus==0");
 137     if (cpus > 0xFF)
 138         cpus = 0xFF;
 139
 140     return      cpus;
 141 }
 142
 143
 144 /* Initialize kernel version of _cpu_capabilities vector (used by KEXTs.) */
 145
 146 static void
 147 commpage_init_cpu_capabilities( void )
 148 {
 149     struct per_proc_info *pp;
 150     procFeatures        *pfp;
 151     int cpus;
 152     int available;
 153
 154     pp = per_proc_info;                                 // use CPU 0's per-proc
 155     pfp = &pp->pf;                                              // point to features in per-proc
 156     available = pfp->Available;
 157
 158     // If AltiVec is disabled make sure it is not reported as available.
 159     if ((available & pfAltivec) == 0) {
 160         _cpu_capabilities &= ~kHasAltivec;
 161     }
 162
 163     if (_cpu_capabilities & kDcbaAvailable) {           // if this processor has DCBA, time it...
 164         _cpu_capabilities |= commpage_time_dcba();      // ...and set kDcbaRecomended if it helps.
 165     }
 166
 167     cpus = commpage_cpus();                             // how many CPUs do we have
 168     if (cpus == 1) _cpu_capabilities |= kUP;
 169     _cpu_capabilities |= (cpus << kNumCPUsShift);
 170 }
 171
 172
 173 /* Copy data into commpage. */
 174
 175  void
 176 commpage_stuff(
 177     int         address,
 178     void        *source,
 179     int         length  )
 180 {
 181     char        *dest = commpage_addr_of(address);
 182
 183     if (dest < next)
 184         panic("commpage overlap: %08 - %08X", dest, next);
 185
 186     bcopy((char*)source,dest,length);
 187
 188     next = (dest + length);
 189 }
 190
 191
 192 /* Modify commpage code in-place for this specific platform. */
 193
 194 static void
 195 commpage_change(
 196     uint32_t    *ptr,
 197     int                 bytes,
 198     uint32_t    search_mask,
 199     uint32_t    search_pattern,
 200     uint32_t    new_mask,
 201     uint32_t    new_pattern,
 202     int                 (*check)(uint32_t instruction)  )
 203 {
 204     int                 words = bytes >> 2;
 205     uint32_t    word;
 206     int                 found_one = 0;
 207
 208     while( (--words) >= 0 ) {
 209         word = *ptr;
 210         if ((word & search_mask)==search_pattern) {
 211             if ((check==NULL) || (check(word))) {       // check instruction if necessary
 212                 found_one = 1;
 213                 word &= ~new_mask;
 214                 word |= new_pattern;
 215                 *ptr = word;
 216             }
 217         }
 218         ptr++;
 219     }
 220
 221     if (!found_one)
 222         panic("commpage opcode not found");
 223 }
 224
 225
 226 /* Check to see if exactly one bit is set in a MTCRF instruction's FXM field.
 227  */
 228 static int
 229 commpage_onebit(
 230     uint32_t    mtcrf )
 231 {
 232     int x = (mtcrf >> 12) & 0xFF;               // isolate the FXM field of the MTCRF
 233
 234     if (x==0)
 235         panic("commpage bad mtcrf");
 236
 237     return      (x & (x-1))==0 ? 1 : 0;         // return 1 iff exactly 1 bit set in FXM field
 238 }
 239
 240
 241 /* Handle kCommPageDCBA bit: this routine uses DCBA.  If the machine we're
 242  * running on doesn't benefit from use of that instruction, map them to NOPs
 243  * in the commpage.
 244  */
 245 static void
 246 commpage_handle_dcbas(
 247     int         address,
 248     int         length  )
 249 {
 250     uint32_t    *ptr, search_mask, search, replace_mask, replace;
 251
 252     if ((_cpu_capabilities & kDcbaAvailable) == 0) {
 253         ptr = commpage_addr_of(address);
 254
 255         search_mask =   0xFC0007FE;             // search x-form opcode bits
 256         search =                0x7C0005EC;             // for a DCBA
 257         replace_mask =  0xFFFFFFFF;             // replace all bits...
 258         replace =               0x60000000;             // ...with a NOP
 259
 260         commpage_change(ptr,length,search_mask,search,replace_mask,replace,NULL);
 261     }
 262 }
 263
 264
 265 /* Handle kCommPageSYNC bit: this routine uses SYNC or LWSYNC.  If we're
 266  * running on a UP machine, map them to NOPs.
 267  */
 268 static void
 269 commpage_handle_syncs(
 270     int         address,
 271     int         length  )
 272 {
 273     uint32_t    *ptr, search_mask, search, replace_mask, replace;
 274
 275     if (_NumCPUs() == 1) {
 276         ptr = commpage_addr_of(address);
 277
 278         search_mask =   0xFC0007FE;             // search x-form opcode bits
 279         search =                0x7C0004AC;             // for a SYNC or LWSYNC
 280         replace_mask =  0xFFFFFFFF;             // replace all bits...
 281         replace =               0x60000000;             // ...with a NOP
 282
 283         commpage_change(ptr,length,search_mask,search,replace_mask,replace,NULL);
 284     }
 285 }
 286
 287
 288 /* Handle kCommPageMTCRF bit.  When this was written (3/03), the assembler did not
 289  * recognize the special form of MTCRF instructions, in which exactly one bit is set
 290  * in the 8-bit mask field.  Bit 11 of the instruction should be set in this case,
 291  * since the 970 and probably other 64-bit processors optimize it.  Once the assembler
 292  * has been updated this code can be removed, though it need not be.
 293  */
 294 static void
 295 commpage_handle_mtcrfs(
 296     int         address,
 297     int         length  )
 298 {
 299     uint32_t    *ptr, search_mask, search, replace_mask, replace;
 300
 301     if (_cpu_capabilities & k64Bit) {
 302         ptr = commpage_addr_of(address);
 303
 304         search_mask =   0xFC0007FE;             // search x-form opcode bits
 305         search =                0x7C000120;             // for a MTCRF
 306         replace_mask =  0x00100000;             // replace bit 11...
 307         replace =               0x00100000;             // ...with a 1-bit
 308
 309         commpage_change(ptr,length,search_mask,search,replace_mask,replace,commpage_onebit);
 310     }
 311 }
 312
 313
 314 /* Copy a routine into comm page if it matches running machine.
 315  */
 316 static void
 317 commpage_stuff_routine(
 318     commpage_descriptor *rd     )
 319 {
 320     char        *routine_code;
 321     int         must,cant;
 322
 323     if (rd->commpage_address != cur_routine) {
 324         if ((cur_routine!=0) && (matched==0))
 325             panic("commpage no match");
 326         cur_routine = rd->commpage_address;
 327         matched = 0;
 328     }
 329
 330     must = _cpu_capabilities & rd->musthave;
 331     cant = _cpu_capabilities & rd->canthave;
 332
 333     if ((must == rd->musthave) && (cant == 0)) {
 334         if (matched)
 335             panic("commpage duplicate matches");
 336         matched = 1;
 337         routine_code = ((char*)rd) + rd->code_offset;
 338
 339         commpage_stuff(rd->commpage_address,routine_code,rd->code_length);
 340
 341         if (rd->special & kCommPageDCBA)
 342             commpage_handle_dcbas(rd->commpage_address,rd->code_length);
 343
 344         if (rd->special & kCommPageSYNC)
 345             commpage_handle_syncs(rd->commpage_address,rd->code_length);
 346
 347         if (rd->special & kCommPageMTCRF)
 348             commpage_handle_mtcrfs(rd->commpage_address,rd->code_length);
 349     }
 350 }
 351
 352
 353 /* Fill in commpage: called once, during kernel initialization, from the
 354  * startup thread before user-mode code is running.
 355  * See the top of this file for a list of what you have to do to add
 356  * a new routine to the commpage.
 357  */
 358 void
 359 commpage_populate( void )
 360 {
 361     char        c1;
 362     short       c2;
 363     addr64_t c8;
 364     static double       two52 = 1048576.0 * 1048576.0 * 4096.0; // 2**52
 365     static double       ten6 = 1000000.0;                                               // 10**6
 366     commpage_descriptor **rd;
 367     short       version = _COMM_PAGE_THIS_VERSION;
 368
 369
 370     commPagePtr = (char*) commpage_allocate();
 371
 372     commpage_init_cpu_capabilities();
 373
 374
 375     /* Stuff in the constants.  We move things into the comm page in strictly
 376      * ascending order, so we can check for overlap and panic if so.
 377      */
 378
 379     commpage_stuff(_COMM_PAGE_VERSION,&version,2);
 380
 381     commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,sizeof(int));
 382
 383     c1 = (_cpu_capabilities & kHasAltivec) ? -1 : 0;
 384     commpage_stuff(_COMM_PAGE_ALTIVEC,&c1,1);
 385
 386     c1 = (_cpu_capabilities & k64Bit) ? -1 : 0;
 387     commpage_stuff(_COMM_PAGE_64_BIT,&c1,1);
 388
 389     if (_cpu_capabilities & kCache32)
 390         c2 = 32;
 391     else if (_cpu_capabilities & kCache64)
 392         c2 = 64;
 393     else if (_cpu_capabilities & kCache128)
 394         c2 = 128;
 395     commpage_stuff(_COMM_PAGE_CACHE_LINESIZE,&c2,2);
 396
 397     commpage_stuff(_COMM_PAGE_2_TO_52,&two52,8);
 398
 399     commpage_stuff(_COMM_PAGE_10_TO_6,&ten6,8);
 400
 401     c8 = 0;                                                                                                     // 0 timestamp means "disabled"
 402     commpage_stuff(_COMM_PAGE_TIMEBASE,&c8,8);
 403     commpage_stuff(_COMM_PAGE_TIMESTAMP,&c8,8);
 404     commpage_stuff(_COMM_PAGE_SEC_PER_TICK,&c8,8);
 405
 406
 407     /* Now the routines.  We try each potential routine in turn,
 408      * and copy in any that "match" the platform we are running on.
 409      * We require that exactly one routine match for each slot in the
 410      * comm page, and panic if not.
 411      *
 412      * The check for overlap assumes that these routines are
 413      * in strictly ascending order, sorted by address in the
 414      * comm page.
 415      */
 416
 417     extern      commpage_descriptor     mach_absolute_time_32;
 418     extern      commpage_descriptor     mach_absolute_time_64;
 419     extern      commpage_descriptor     spinlock_32_try_mp;
 420     extern      commpage_descriptor     spinlock_32_try_up;
 421     extern      commpage_descriptor     spinlock_64_try_mp;
 422     extern      commpage_descriptor     spinlock_64_try_up;
 423     extern      commpage_descriptor     spinlock_32_lock_mp;
 424     extern      commpage_descriptor     spinlock_32_lock_up;
 425     extern      commpage_descriptor     spinlock_64_lock_mp;
 426     extern      commpage_descriptor     spinlock_64_lock_up;
 427     extern      commpage_descriptor     spinlock_32_unlock_mp;
 428     extern      commpage_descriptor     spinlock_32_unlock_up;
 429     extern      commpage_descriptor     spinlock_64_unlock_mp;
 430     extern      commpage_descriptor     spinlock_64_unlock_up;
 431     extern      commpage_descriptor     pthread_getspecific_sprg3;
 432     extern      commpage_descriptor     pthread_getspecific_uftrap;
 433     extern      commpage_descriptor     gettimeofday_32;
 434     extern      commpage_descriptor     gettimeofday_64;
 435     extern      commpage_descriptor     commpage_flush_dcache;
 436     extern      commpage_descriptor     commpage_flush_icache;
 437     extern      commpage_descriptor     pthread_self_sprg3;
 438     extern      commpage_descriptor     pthread_self_uftrap;
 439     extern      commpage_descriptor     spinlock_relinquish;
 440     extern      commpage_descriptor     bzero_32;
 441     extern      commpage_descriptor     bzero_128;
 442     extern      commpage_descriptor     bcopy_g3;
 443     extern      commpage_descriptor     bcopy_g4;
 444     extern      commpage_descriptor     bcopy_970;
 445     extern      commpage_descriptor     bcopy_64;
 446     extern      commpage_descriptor     bigcopy_970;
 447
 448     static      commpage_descriptor     *routines[] = {
 449         &mach_absolute_time_32,
 450         &mach_absolute_time_64,
 451         &spinlock_32_try_mp,
 452         &spinlock_32_try_up,
 453         &spinlock_64_try_mp,
 454         &spinlock_64_try_up,
 455         &spinlock_32_lock_mp,
 456         &spinlock_32_lock_up,
 457         &spinlock_64_lock_mp,
 458         &spinlock_64_lock_up,
 459         &spinlock_32_unlock_mp,
 460         &spinlock_32_unlock_up,
 461         &spinlock_64_unlock_mp,
 462         &spinlock_64_unlock_up,
 463         &pthread_getspecific_sprg3,
 464         &pthread_getspecific_uftrap,
 465         &gettimeofday_32,
 466         &gettimeofday_64,
 467         &commpage_flush_dcache,
 468         &commpage_flush_icache,
 469         &pthread_self_sprg3,
 470         &pthread_self_uftrap,
 471         &spinlock_relinquish,
 472         &bzero_32,
 473         &bzero_128,
 474         &bcopy_g3,
 475         &bcopy_g4,
 476         &bcopy_970,
 477         &bcopy_64,
 478         &bigcopy_970,
 479         NULL };
 480
 481     for( rd = routines; *rd != NULL ; rd++ )
 482         commpage_stuff_routine(*rd);
 483
 484     if (!matched)
 485         panic("commpage no match on last routine");
 486
 487     if (next > (commPagePtr + _COMM_PAGE_AREA_USED))
 488         panic("commpage overflow");
 489
 490     sync_cache_virtual((vm_offset_t) commPagePtr,_COMM_PAGE_AREA_USED); // make all that new code executable
 491
 492 }
 493