osfmk/i386/commpage/commpage.c

   1 /*
   2  * Copyright (c) 2003 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 /*
  24  *      Here's what to do if you want to add a new routine to the comm page:
  25  *
  26  *              1. Add a definition for it's address in osfmk/ppc/cpu_capabilities.h,
  27  *                 being careful to reserve room for future expansion.
  28  *
  29  *              2. Write one or more versions of the routine, each with it's own
  30  *                 commpage_descriptor.  The tricky part is getting the "special",
  31  *                 "musthave", and "canthave" fields right, so that exactly one
  32  *                 version of the routine is selected for every machine.
  33  *                 The source files should be in osfmk/ppc/commpage/.
  34  *
  35  *              3. Add a ptr to your new commpage_descriptor(s) in the "routines"
  36  *                 array in commpage_populate().  Of course, you'll also have to
  37  *                 declare them "extern" in commpage_populate().
  38  *
  39  *              4. Write the code in Libc to use the new routine.
  40  */
  41
  42 #include <mach/mach_types.h>
  43 #include <mach/machine.h>
  44 #include <i386/machine_routines.h>
  45 #include <machine/cpu_capabilities.h>
  46 #include <machine/commpage.h>
  47 #include <machine/pmap.h>
  48 #include <vm/vm_kern.h>
  49 #include <mach/vm_map.h>
  50
  51 static  uintptr_t       next = 0;                       // next available byte in comm page
  52 static  int             cur_routine = 0;        // comm page address of "current" routine
  53 static  int             matched;                        // true if we've found a match for "current" routine
  54
  55 int     _cpu_capabilities = 0;          // define the capability vector
  56
  57 char    *commPagePtr = NULL;            // virtual address of comm page in kernel map
  58
  59 /* Allocate the commpage and add to the shared submap created by vm:
  60  *      1. allocate a page in the kernel map (RW)
  61  *      2. wire it down
  62  *      3. make a memory entry out of it
  63  *      4. map that entry into the shared comm region map (R-only)
  64  */
  65
  66 static  void*
  67 commpage_allocate( void )
  68 {
  69     extern  vm_map_t    com_region_map;             // the shared submap, set up in vm init
  70     vm_offset_t         kernel_addr;                // address of commpage in kernel map
  71     vm_offset_t         zero = 0;
  72     vm_size_t           size = _COMM_PAGE_AREA_LENGTH;
  73     ipc_port_t          handle;
  74
  75     if (com_region_map == NULL)
  76         panic("commpage map is null");
  77
  78     if (vm_allocate(kernel_map,&kernel_addr,_COMM_PAGE_AREA_LENGTH,VM_FLAGS_ANYWHERE))
  79         panic("cannot allocate commpage");
  80
  81     if (vm_map_wire(kernel_map,kernel_addr,kernel_addr+_COMM_PAGE_AREA_LENGTH,VM_PROT_DEFAULT,FALSE))
  82         panic("cannot wire commpage");
  83
  84     if (mach_make_memory_entry( kernel_map,         // target map
  85                                 &size,              // size
  86                                 kernel_addr,        // offset (address in kernel map)
  87                                 VM_PROT_DEFAULT,    // map it RW
  88                                 &handle,            // this is the object handle we get
  89                                 NULL ))             // parent_entry (what is this?)
  90         panic("cannot make entry for commpage");
  91
  92     if (vm_map_64(  com_region_map,                 // target map (shared submap)
  93                     &zero,                          // address (map into 1st page in submap)
  94                     _COMM_PAGE_AREA_LENGTH,         // size
  95                     0,                              // mask
  96                     VM_FLAGS_FIXED,                 // flags (it must be 1st page in submap)
  97                     handle,                         // port is the memory entry we just made
  98                     0,                              // offset (map 1st page in memory entry)
  99                     FALSE,                          // copy
 100                     VM_PROT_READ,                   // cur_protection (R-only in user map)
 101                     VM_PROT_READ,                   // max_protection
 102                     VM_INHERIT_SHARE ))             // inheritance
 103         panic("cannot map commpage");
 104
 105     ipc_port_release(handle);
 106
 107     return (void*) kernel_addr;                     // return address in kernel map
 108 }
 109
 110 /* Get address (in kernel map) of a commpage field. */
 111
 112 static  void*
 113 commpage_addr_of(
 114     int     addr_at_runtime )
 115 {
 116     return  (void*) ((uintptr_t)commPagePtr + addr_at_runtime - _COMM_PAGE_BASE_ADDRESS);
 117 }
 118
 119 /* Determine number of CPUs on this system.  We cannot rely on
 120  * machine_info.max_cpus this early in the boot.
 121  */
 122 static int
 123 commpage_cpus( void )
 124 {
 125         int cpus;
 126
 127         cpus = ml_get_max_cpus();                   // NB: this call can block
 128
 129         if (cpus == 0)
 130                 panic("commpage cpus==0");
 131         if (cpus > 0xFF)
 132                 cpus = 0xFF;
 133
 134         return cpus;
 135 }
 136
 137 /* Initialize kernel version of _cpu_capabilities vector (used by KEXTs.) */
 138
 139 static void
 140 commpage_init_cpu_capabilities( void )
 141 {
 142         int bits;
 143         int cpus;
 144         ml_cpu_info_t cpu_info;
 145
 146         bits = 0;
 147         ml_cpu_get_info(&cpu_info);
 148
 149         switch (cpu_info.vector_unit) {
 150                 case 5:
 151                         bits |= kHasPNI;
 152                         /* fall thru */
 153                 case 4:
 154                         bits |= kHasSSE2;
 155                         /* fall thru */
 156                 case 3:
 157                         bits |= kHasSSE;
 158                         /* fall thru */
 159                 case 2:
 160                         bits |= kHasMMX;
 161                 default:
 162                         break;
 163         }
 164         switch (cpu_info.cache_line_size) {
 165                 case 128:
 166                         bits |= kCache128;
 167                         break;
 168                 case 64:
 169                         bits |= kCache64;
 170                         break;
 171                 case 32:
 172                         bits |= kCache32;
 173                         break;
 174                 default:
 175                         break;
 176         }
 177         cpus = commpage_cpus();                 // how many CPUs do we have
 178
 179         if (cpus == 1)
 180                 bits |= kUP;
 181
 182         bits |= (cpus << kNumCPUsShift);
 183
 184         _cpu_capabilities = bits;               // set kernel version for use by drivers etc
 185 }
 186
 187 /* Copy data into commpage. */
 188
 189 static void
 190 commpage_stuff(
 191     int         address,
 192     void        *source,
 193     int         length  )
 194 {
 195     void        *dest = commpage_addr_of(address);
 196
 197     if ((uintptr_t)dest < next)
 198         panic("commpage overlap");
 199
 200     bcopy(source,dest,length);
 201
 202     next = ((uintptr_t)dest + length);
 203 }
 204
 205 /* Copy a routine into comm page if it matches running machine.
 206  */
 207 static void
 208 commpage_stuff_routine(
 209     commpage_descriptor *rd     )
 210 {
 211     int         must,cant;
 212
 213     if (rd->commpage_address != cur_routine) {
 214         if ((cur_routine!=0) && (matched==0))
 215             panic("commpage no match");
 216         cur_routine = rd->commpage_address;
 217         matched = 0;
 218     }
 219
 220     must = _cpu_capabilities & rd->musthave;
 221     cant = _cpu_capabilities & rd->canthave;
 222
 223     if ((must == rd->musthave) && (cant == 0)) {
 224         if (matched)
 225             panic("commpage duplicate matches");
 226         matched = 1;
 227
 228         commpage_stuff(rd->commpage_address,rd->code_address,rd->code_length);
 229         }
 230 }
 231
 232 /* Fill in commpage: called once, during kernel initialization, from the
 233  * startup thread before user-mode code is running.
 234  * See the top of this file for a list of what you have to do to add
 235  * a new routine to the commpage.
 236  */
 237
 238 void
 239 commpage_populate( void )
 240 {
 241         commpage_descriptor **rd;
 242         short   version = _COMM_PAGE_THIS_VERSION;
 243         void    *sig_addr;
 244
 245         extern char commpage_sigs_begin[];
 246         extern char commpage_sigs_end[];
 247
 248         extern commpage_descriptor commpage_mach_absolute_time;
 249         extern commpage_descriptor commpage_spin_lock_try_mp;
 250         extern commpage_descriptor commpage_spin_lock_try_up;
 251         extern commpage_descriptor commpage_spin_lock_mp;
 252         extern commpage_descriptor commpage_spin_lock_up;
 253         extern commpage_descriptor commpage_spin_unlock;
 254         extern commpage_descriptor commpage_pthread_getspecific;
 255         extern commpage_descriptor commpage_gettimeofday;
 256         extern commpage_descriptor commpage_sys_flush_dcache;
 257         extern commpage_descriptor commpage_sys_icache_invalidate;
 258         extern commpage_descriptor commpage_pthread_self;
 259         extern commpage_descriptor commpage_relinquish;
 260         extern commpage_descriptor commpage_bzero_scalar;
 261         extern commpage_descriptor commpage_bcopy_scalar;
 262
 263         static  commpage_descriptor *routines[] = {
 264                 &commpage_mach_absolute_time,
 265                 &commpage_spin_lock_try_mp,
 266                 &commpage_spin_lock_try_up,
 267                 &commpage_spin_lock_mp,
 268                 &commpage_spin_lock_up,
 269                 &commpage_spin_unlock,
 270                 &commpage_pthread_getspecific,
 271                 &commpage_gettimeofday,
 272                 &commpage_sys_flush_dcache,
 273                 &commpage_sys_icache_invalidate,
 274                 &commpage_pthread_self,
 275                 &commpage_relinquish,
 276                 &commpage_bzero_scalar,
 277                 &commpage_bcopy_scalar,
 278                 NULL
 279         };
 280
 281         commPagePtr = (char *)commpage_allocate();
 282
 283         commpage_init_cpu_capabilities();
 284
 285         /* Stuff in the constants.  We move things into the comm page in strictly
 286         * ascending order, so we can check for overlap and panic if so.
 287         */
 288
 289         commpage_stuff(_COMM_PAGE_VERSION,&version,sizeof(short));
 290         commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,
 291                 sizeof(int));
 292
 293         for( rd = routines; *rd != NULL ; rd++ )
 294                 commpage_stuff_routine(*rd);
 295
 296         if (!matched)
 297                 panic("commpage no match on last routine");
 298
 299         if (next > ((uintptr_t)commPagePtr + PAGE_SIZE))
 300                 panic("commpage overflow");
 301
 302 #define STUFF_SIG(addr, func) \
 303         extern char commpage_sig_ ## func [];                                   \
 304         sig_addr = (void *)(    (uintptr_t)_COMM_PAGE_BASE_ADDRESS +            \
 305                                 (uintptr_t)_COMM_PAGE_SIGS_OFFSET + 0x1000 +    \
 306                                 (uintptr_t)&commpage_sig_ ## func -             \
 307                                 (uintptr_t)&commpage_sigs_begin );              \
 308         commpage_stuff(addr + _COMM_PAGE_SIGS_OFFSET, &sig_addr, sizeof(void *));
 309
 310         STUFF_SIG(_COMM_PAGE_ABSOLUTE_TIME, mach_absolute_time);
 311         STUFF_SIG(_COMM_PAGE_SPINLOCK_TRY, spin_lock_try);
 312         STUFF_SIG(_COMM_PAGE_SPINLOCK_LOCK, spin_lock);
 313         STUFF_SIG(_COMM_PAGE_SPINLOCK_UNLOCK, spin_unlock);
 314         STUFF_SIG(_COMM_PAGE_PTHREAD_GETSPECIFIC, pthread_getspecific);
 315         STUFF_SIG(_COMM_PAGE_GETTIMEOFDAY, gettimeofday);
 316         STUFF_SIG(_COMM_PAGE_FLUSH_DCACHE, sys_dcache_flush);
 317         STUFF_SIG(_COMM_PAGE_FLUSH_ICACHE, sys_icache_invalidate);
 318         STUFF_SIG(_COMM_PAGE_PTHREAD_SELF, pthread_self);
 319         STUFF_SIG(_COMM_PAGE_BZERO, bzero);
 320         STUFF_SIG(_COMM_PAGE_BCOPY, bcopy);
 321         STUFF_SIG(_COMM_PAGE_MEMCPY, memmove);
 322
 323         commpage_stuff(_COMM_PAGE_BASE_ADDRESS + _COMM_PAGE_SIGS_OFFSET + 0x1000, &commpage_sigs_begin,
 324                         (uintptr_t)&commpage_sigs_end - (uintptr_t)&commpage_sigs_begin);
 325 }