]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/i386/commpage/commpage.c
xnu-1228.9.59.tar.gz
[apple/xnu.git] / osfmk / i386 / commpage / commpage.c
index 209d6e32bbe8f2338529fef4499d27c37993bc53..b2bd5af50c07347ce031452dd3b3ed610e18096b 100644 (file)
@@ -1,16 +1,19 @@
 /*
- * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003-2007 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
- * 
- * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  * This file contains Original Code and/or Modifications of Original Code
  * as defined in and that are subject to the Apple Public Source License
  * Version 2.0 (the 'License'). You may not use this file except in
- * compliance with the License. Please obtain a copy of the License at
- * http://www.opensource.apple.com/apsl/ and read it before using this
- * file.
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
+ * 
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
  * 
  * The Original Code and all software distributed under the License are
  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * Please see the License for the specific language governing rights and
  * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 
 /*
  *     Here's what to do if you want to add a new routine to the comm page:
  *
- *             1. Add a definition for it's address in osfmk/ppc/cpu_capabilities.h,
+ *             1. Add a definition for it's address in osfmk/i386/cpu_capabilities.h,
  *                being careful to reserve room for future expansion.
  *
  *             2. Write one or more versions of the routine, each with it's own
  *                commpage_descriptor.  The tricky part is getting the "special",
  *                "musthave", and "canthave" fields right, so that exactly one
  *                version of the routine is selected for every machine.
- *                The source files should be in osfmk/ppc/commpage/.
+ *                The source files should be in osfmk/i386/commpage/.
  *
  *             3. Add a ptr to your new commpage_descriptor(s) in the "routines"
- *                array in commpage_populate().  Of course, you'll also have to
- *                declare them "extern" in commpage_populate().
+ *                array in osfmk/i386/commpage/commpage_asm.s.  There are two
+ *                arrays, one for the 32-bit and one for the 64-bit commpage.
  *
  *             4. Write the code in Libc to use the new routine.
  */
 
 #include <mach/mach_types.h>
 #include <mach/machine.h>
+#include <mach/vm_map.h>
 #include <i386/machine_routines.h>
+#include <i386/misc_protos.h>
+#include <i386/tsc.h>
+#include <i386/cpu_data.h>
 #include <machine/cpu_capabilities.h>
 #include <machine/commpage.h>
 #include <machine/pmap.h>
 #include <vm/vm_kern.h>
-#include <mach/vm_map.h>
+#include <vm/vm_map.h>
+#include <ipc/ipc_port.h>
+
+#include <kern/page_decrypt.h>
+
+/* the lists of commpage routines are in commpage_asm.s  */
+extern commpage_descriptor*    commpage_32_routines[];
+extern commpage_descriptor*    commpage_64_routines[];
 
-static  uintptr_t      next = 0;                       // next available byte in comm page
-static  int            cur_routine = 0;        // comm page address of "current" routine
-static  int            matched;                        // true if we've found a match for "current" routine
+/* translated commpage descriptors from commpage_sigs.c  */
+extern commpage_descriptor sigdata_descriptor;
+extern commpage_descriptor *ba_descriptors[];
 
+extern vm_map_t        commpage32_map; // the shared submap, set up in vm init
+extern vm_map_t        commpage64_map; // the shared submap, set up in vm init
+
+char   *commPagePtr32 = NULL;          // virtual addr in kernel map of 32-bit commpage
+char   *commPagePtr64 = NULL;          // ...and of 64-bit commpage
 int     _cpu_capabilities = 0;          // define the capability vector
 
-char    *commPagePtr = NULL;            // virtual address of comm page in kernel map
+int    noVMX = 0;              /* if true, do not set kHasAltivec in ppc _cpu_capabilities */
+
+static uintptr_t next;                 // next available byte in comm page
+static int             cur_routine;            // comm page address of "current" routine
+static int             matched;                // true if we've found a match for "current" routine
+
+static char    *commPagePtr;           // virtual addr in kernel map of commpage we are working on
+static size_t  commPageBaseOffset;     // add to 32-bit runtime address to get offset in commpage
+
+static commpage_time_data      *time_data32 = NULL;
+static commpage_time_data      *time_data64 = NULL;
 
 /* Allocate the commpage and add to the shared submap created by vm:
  *     1. allocate a page in the kernel map (RW)
@@ -67,56 +96,70 @@ char    *commPagePtr = NULL;            // virtual address of comm page in kerne
  */
 
 static  void*
-commpage_allocate( void )
+commpage_allocate( 
+       vm_map_t        submap,                 // commpage32_map or commpage_map64
+       size_t          area_used )             // _COMM_PAGE32_AREA_USED or _COMM_PAGE64_AREA_USED
 {
-    extern  vm_map_t    com_region_map;             // the shared submap, set up in vm init
-    vm_offset_t         kernel_addr;                // address of commpage in kernel map
-    vm_offset_t         zero = 0;
-    vm_size_t           size = _COMM_PAGE_AREA_LENGTH;
-    ipc_port_t          handle;
-
-    if (com_region_map == NULL)
-        panic("commpage map is null");
-
-    if (vm_allocate(kernel_map,&kernel_addr,_COMM_PAGE_AREA_LENGTH,VM_FLAGS_ANYWHERE))
-        panic("cannot allocate commpage");
-
-    if (vm_map_wire(kernel_map,kernel_addr,kernel_addr+_COMM_PAGE_AREA_LENGTH,VM_PROT_DEFAULT,FALSE))
-        panic("cannot wire commpage");
-
-    if (mach_make_memory_entry( kernel_map,         // target map
-                                &size,              // size 
-                                kernel_addr,        // offset (address in kernel map)
-                                VM_PROT_DEFAULT,    // map it RW
-                                &handle,            // this is the object handle we get
-                                NULL ))             // parent_entry (what is this?)
-        panic("cannot make entry for commpage");
-
-    if (vm_map_64(  com_region_map,                 // target map (shared submap)
-                    &zero,                          // address (map into 1st page in submap)
-                    _COMM_PAGE_AREA_LENGTH,         // size
-                    0,                              // mask
-                    VM_FLAGS_FIXED,                 // flags (it must be 1st page in submap)
-                    handle,                         // port is the memory entry we just made
-                    0,                              // offset (map 1st page in memory entry)
-                    FALSE,                          // copy
-                    VM_PROT_READ,                   // cur_protection (R-only in user map)
-                    VM_PROT_READ,                   // max_protection
-                    VM_INHERIT_SHARE ))             // inheritance
-        panic("cannot map commpage");
-
-    ipc_port_release(handle);
-
-    return (void*) kernel_addr;                     // return address in kernel map
+       vm_offset_t     kernel_addr = 0;        // address of commpage in kernel map
+       vm_offset_t     zero = 0;
+       vm_size_t       size = area_used;       // size actually populated
+       vm_map_entry_t  entry;
+       ipc_port_t      handle;
+
+       if (submap == NULL)
+               panic("commpage submap is null");
+
+       if (vm_map(kernel_map,&kernel_addr,area_used,0,VM_FLAGS_ANYWHERE,NULL,0,FALSE,VM_PROT_ALL,VM_PROT_ALL,VM_INHERIT_NONE))
+               panic("cannot allocate commpage");
+
+       if (vm_map_wire(kernel_map,kernel_addr,kernel_addr+area_used,VM_PROT_DEFAULT,FALSE))
+               panic("cannot wire commpage");
+
+       /* 
+        * Now that the object is created and wired into the kernel map, mark it so that no delay
+        * copy-on-write will ever be performed on it as a result of mapping it into user-space.
+        * If such a delayed copy ever occurred, we could remove the kernel's wired mapping - and
+        * that would be a real disaster.
+        *
+        * JMM - What we really need is a way to create it like this in the first place.
+        */
+       if (!vm_map_lookup_entry( kernel_map, vm_map_trunc_page(kernel_addr), &entry) || entry->is_sub_map)
+               panic("cannot find commpage entry");
+       entry->object.vm_object->copy_strategy = MEMORY_OBJECT_COPY_NONE;
+
+       if (mach_make_memory_entry( kernel_map,         // target map
+                                   &size,              // size 
+                                   kernel_addr,        // offset (address in kernel map)
+                                   VM_PROT_ALL,        // map it RWX
+                                   &handle,            // this is the object handle we get
+                                   NULL ))             // parent_entry (what is this?)
+               panic("cannot make entry for commpage");
+
+       if (vm_map_64(  submap,                         // target map (shared submap)
+                       &zero,                          // address (map into 1st page in submap)
+                       area_used,                      // size
+                       0,                              // mask
+                       VM_FLAGS_FIXED,                 // flags (it must be 1st page in submap)
+                       handle,                         // port is the memory entry we just made
+                       0,                              // offset (map 1st page in memory entry)
+                       FALSE,                          // copy
+                       VM_PROT_READ|VM_PROT_EXECUTE,   // cur_protection (R-only in user map)
+                       VM_PROT_READ|VM_PROT_EXECUTE,   // max_protection
+                       VM_INHERIT_SHARE ))             // inheritance
+               panic("cannot map commpage");
+
+       ipc_port_release(handle);
+
+       return (void*) kernel_addr;                     // return address in kernel map
 }
 
 /* Get address (in kernel map) of a commpage field. */
 
-static  void*
+static void*
 commpage_addr_of(
     int     addr_at_runtime )
 {
-    return  (void*) ((uintptr_t)commPagePtr + addr_at_runtime - _COMM_PAGE_BASE_ADDRESS);
+    return  (void*) ((uintptr_t)commPagePtr + addr_at_runtime - commPageBaseOffset);
 }
 
 /* Determine number of CPUs on this system.  We cannot rely on
@@ -150,8 +193,17 @@ commpage_init_cpu_capabilities( void )
        ml_cpu_get_info(&cpu_info);
        
        switch (cpu_info.vector_unit) {
+               case 8:
+                       bits |= kHasSSE4_2;
+                       /* fall thru */
+               case 7:
+                       bits |= kHasSSE4_1;
+                       /* fall thru */
+               case 6:
+                       bits |= kHasSupplementalSSE3;
+                       /* fall thru */
                case 5:
-                       bits |= kHasPNI;
+                       bits |= kHasSSE3;
                        /* fall thru */
                case 4:
                        bits |= kHasSSE2;
@@ -184,27 +236,76 @@ commpage_init_cpu_capabilities( void )
 
        bits |= (cpus << kNumCPUsShift);
 
+       bits |= kFastThreadLocalStorage;        // we use %gs for TLS
+
+       if (cpu_mode_is64bit())                 // k64Bit means processor is 64-bit capable
+               bits |= k64Bit;
+
+       if (tscFreq <= SLOW_TSC_THRESHOLD)      /* is TSC too slow for _commpage_nanotime?  */
+               bits |= kSlow;
+
        _cpu_capabilities = bits;               // set kernel version for use by drivers etc
 }
 
+int
+_get_cpu_capabilities(void)
+{
+       return _cpu_capabilities;
+}
+
 /* Copy data into commpage. */
 
 static void
 commpage_stuff(
     int        address,
-    void       *source,
+    const void         *source,
     int        length  )
 {    
     void       *dest = commpage_addr_of(address);
     
     if ((uintptr_t)dest < next)
-        panic("commpage overlap");
+        panic("commpage overlap at address 0x%x, %p < 0x%lx", address, dest, next);
     
     bcopy(source,dest,length);
     
     next = ((uintptr_t)dest + length);
 }
 
+static void
+commpage_stuff_swap(
+       int     address,
+       void    *source,
+       int     length,
+       int     legacy )
+{
+       if ( legacy ) {
+               void *dest = commpage_addr_of(address);
+               dest = (void *)((uintptr_t) dest + _COMM_PAGE_SIGS_OFFSET);
+               switch (length) {
+                       case 2:
+                               OSWriteSwapInt16(dest, 0, *(uint16_t *)source);
+                               break;
+                       case 4:
+                               OSWriteSwapInt32(dest, 0, *(uint32_t *)source);
+                               break;
+                       case 8:
+                               OSWriteSwapInt64(dest, 0, *(uint64_t *)source);
+                               break;
+               }
+       }
+}
+
+static void
+commpage_stuff2(
+       int     address,
+       void    *source,
+       int     length,
+       int     legacy )
+{
+       commpage_stuff_swap(address, source, length, legacy);
+       commpage_stuff(address, source, length);
+}
+
 /* Copy a routine into comm page if it matches running machine.
  */
 static void
@@ -215,7 +316,7 @@ commpage_stuff_routine(
     
     if (rd->commpage_address != cur_routine) {
         if ((cur_routine!=0) && (matched==0))
-            panic("commpage no match");
+            panic("commpage no match for last, next address %08lx", rd->commpage_address);
         cur_routine = rd->commpage_address;
         matched = 0;
     }
@@ -225,104 +326,232 @@ commpage_stuff_routine(
     
     if ((must == rd->musthave) && (cant == 0)) {
         if (matched)
-            panic("commpage duplicate matches");
+            panic("commpage multiple matches for address %08lx", rd->commpage_address);
         matched = 1;
         
         commpage_stuff(rd->commpage_address,rd->code_address,rd->code_length);
        }
 }
 
-/* Fill in commpage: called once, during kernel initialization, from the
- * startup thread before user-mode code is running.
- * See the top of this file for a list of what you have to do to add
- * a new routine to the commpage.
+/* Fill in the 32- or 64-bit commpage.  Called once for each.
+ * The 32-bit ("legacy") commpage has a bunch of stuff added to it
+ * for translated processes, some of which is byte-swapped.
  */
 
-void
-commpage_populate( void )
+static void
+commpage_populate_one( 
+       vm_map_t        submap,         // commpage32_map or compage64_map
+       char **         kernAddressPtr, // &commPagePtr32 or &commPagePtr64
+       size_t          area_used,      // _COMM_PAGE32_AREA_USED or _COMM_PAGE64_AREA_USED
+       size_t          base_offset,    // will become commPageBaseOffset
+       commpage_descriptor** commpage_routines, // list of routine ptrs for this commpage
+       boolean_t       legacy,         // true if 32-bit commpage
+       commpage_time_data** time_data, // &time_data32 or &time_data64
+       const char*     signature )     // "commpage 32-bit" or "commpage 64-bit"
 {
+       short   c2;
+       static double   two52 = 1048576.0 * 1048576.0 * 4096.0; // 2**52
+       static double   ten6 = 1000000.0;                       // 10**6
        commpage_descriptor **rd;
        short   version = _COMM_PAGE_THIS_VERSION;
-       void    *sig_addr;
+       int             swapcaps;
 
-       extern char commpage_sigs_begin[];
-       extern char commpage_sigs_end[];
-       extern commpage_descriptor commpage_mach_absolute_time;
-       extern commpage_descriptor commpage_spin_lock_try_mp;
-       extern commpage_descriptor commpage_spin_lock_try_up;
-       extern commpage_descriptor commpage_spin_lock_mp;
-       extern commpage_descriptor commpage_spin_lock_up;
-       extern commpage_descriptor commpage_spin_unlock;
-       extern commpage_descriptor commpage_pthread_getspecific;
-       extern commpage_descriptor commpage_gettimeofday;
-       extern commpage_descriptor commpage_sys_flush_dcache;
-       extern commpage_descriptor commpage_sys_icache_invalidate;
-       extern commpage_descriptor commpage_pthread_self;
-       extern commpage_descriptor commpage_relinquish;
-       extern commpage_descriptor commpage_bzero_scalar;
-       extern commpage_descriptor commpage_bcopy_scalar;
-
-       static  commpage_descriptor *routines[] = {
-               &commpage_mach_absolute_time,
-               &commpage_spin_lock_try_mp,
-               &commpage_spin_lock_try_up,
-               &commpage_spin_lock_mp,
-               &commpage_spin_lock_up,
-               &commpage_spin_unlock,
-               &commpage_pthread_getspecific,
-               &commpage_gettimeofday,
-               &commpage_sys_flush_dcache,
-               &commpage_sys_icache_invalidate,
-               &commpage_pthread_self,
-               &commpage_relinquish,
-               &commpage_bzero_scalar,
-               &commpage_bcopy_scalar,
-               NULL
-       };
-
-       commPagePtr = (char *)commpage_allocate();
-
-       commpage_init_cpu_capabilities();
+       next = (uintptr_t) NULL;
+       cur_routine = 0;
+       commPagePtr = (char *)commpage_allocate( submap, (vm_size_t) area_used );
+       *kernAddressPtr = commPagePtr;                          // save address either in commPagePtr32 or 64
+       commPageBaseOffset = base_offset;
+       
+       *time_data = commpage_addr_of( _COMM_PAGE_TIME_DATA_START );
 
        /* Stuff in the constants.  We move things into the comm page in strictly
        * ascending order, so we can check for overlap and panic if so.
        */
+       commpage_stuff(_COMM_PAGE_SIGNATURE,signature,strlen(signature));
+       commpage_stuff2(_COMM_PAGE_VERSION,&version,sizeof(short),legacy);
+       commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,sizeof(int));
+
+       /* excuse our magic constants, we cannot include ppc/cpu_capabilities.h */
+       /* always set kCache32 and kDcbaAvailable */
+       swapcaps =  0x44;
+       if ( _cpu_capabilities & kUP )
+               swapcaps |= (kUP + (1 << kNumCPUsShift));
+       else
+               swapcaps |= 2 << kNumCPUsShift; /* limit #cpus to 2 */
+       if ( ! noVMX )          /* if rosetta will be emulating altivec... */
+               swapcaps |= 0x101;      /* ...then set kHasAltivec and kDataStreamsAvailable too */
+       commpage_stuff_swap(_COMM_PAGE_CPU_CAPABILITIES, &swapcaps, sizeof(int), legacy);
+       c2 = 32;
+       commpage_stuff_swap(_COMM_PAGE_CACHE_LINESIZE,&c2,2,legacy);
+
+       if (_cpu_capabilities & kCache32)
+               c2 = 32;
+       else if (_cpu_capabilities & kCache64)
+               c2 = 64;
+       else if (_cpu_capabilities & kCache128)
+               c2 = 128;
+       commpage_stuff(_COMM_PAGE_CACHE_LINESIZE,&c2,2);
+
+       if ( legacy ) {
+               commpage_stuff2(_COMM_PAGE_2_TO_52,&two52,8,legacy);
+               commpage_stuff2(_COMM_PAGE_10_TO_6,&ten6,8,legacy);
+       }
 
-       commpage_stuff(_COMM_PAGE_VERSION,&version,sizeof(short));
-       commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,
-               sizeof(int));
-
-       for( rd = routines; *rd != NULL ; rd++ )
+       for( rd = commpage_routines; *rd != NULL ; rd++ )
                commpage_stuff_routine(*rd);
 
        if (!matched)
                panic("commpage no match on last routine");
 
-       if (next > ((uintptr_t)commPagePtr + PAGE_SIZE))
-               panic("commpage overflow");
-
-#define STUFF_SIG(addr, func) \
-       extern char commpage_sig_ ## func [];                                   \
-       sig_addr = (void *)(    (uintptr_t)_COMM_PAGE_BASE_ADDRESS +            \
-                               (uintptr_t)_COMM_PAGE_SIGS_OFFSET + 0x1000 +    \
-                               (uintptr_t)&commpage_sig_ ## func -             \
-                               (uintptr_t)&commpage_sigs_begin );              \
-       commpage_stuff(addr + _COMM_PAGE_SIGS_OFFSET, &sig_addr, sizeof(void *));
-
-       STUFF_SIG(_COMM_PAGE_ABSOLUTE_TIME, mach_absolute_time);
-       STUFF_SIG(_COMM_PAGE_SPINLOCK_TRY, spin_lock_try);
-       STUFF_SIG(_COMM_PAGE_SPINLOCK_LOCK, spin_lock);
-       STUFF_SIG(_COMM_PAGE_SPINLOCK_UNLOCK, spin_unlock);
-       STUFF_SIG(_COMM_PAGE_PTHREAD_GETSPECIFIC, pthread_getspecific);
-       STUFF_SIG(_COMM_PAGE_GETTIMEOFDAY, gettimeofday);
-       STUFF_SIG(_COMM_PAGE_FLUSH_DCACHE, sys_dcache_flush);
-       STUFF_SIG(_COMM_PAGE_FLUSH_ICACHE, sys_icache_invalidate); 
-       STUFF_SIG(_COMM_PAGE_PTHREAD_SELF, pthread_self);
-       STUFF_SIG(_COMM_PAGE_BZERO, bzero);
-       STUFF_SIG(_COMM_PAGE_BCOPY, bcopy);
-       STUFF_SIG(_COMM_PAGE_MEMCPY, memmove);
-
-       commpage_stuff(_COMM_PAGE_BASE_ADDRESS + _COMM_PAGE_SIGS_OFFSET + 0x1000, &commpage_sigs_begin,
-                       (uintptr_t)&commpage_sigs_end - (uintptr_t)&commpage_sigs_begin);       
+       if (next > (uintptr_t)_COMM_PAGE_END)
+               panic("commpage overflow: next = 0x%08lx, commPagePtr = 0x%08lx", next, (uintptr_t)commPagePtr);
+
+       if ( legacy ) {
+               next = (uintptr_t) NULL;
+               for( rd = ba_descriptors; *rd != NULL ; rd++ )
+                       commpage_stuff_routine(*rd);
+
+               next = (uintptr_t) NULL;
+               commpage_stuff_routine(&sigdata_descriptor);
+       }       
+}
+
+
+/* Fill in commpages: called once, during kernel initialization, from the
+ * startup thread before user-mode code is running.
+ *
+ * See the top of this file for a list of what you have to do to add
+ * a new routine to the commpage.
+ */  
+
+void
+commpage_populate( void )
+{
+       commpage_init_cpu_capabilities();
+       
+       commpage_populate_one(  commpage32_map, 
+                               &commPagePtr32,
+                               _COMM_PAGE32_AREA_USED,
+                               _COMM_PAGE32_BASE_ADDRESS,
+                               commpage_32_routines, 
+                               TRUE,                   /* legacy (32-bit) commpage */
+                               &time_data32,
+                               "commpage 32-bit");
+       pmap_commpage32_init((vm_offset_t) commPagePtr32, _COMM_PAGE32_BASE_ADDRESS, 
+                          _COMM_PAGE32_AREA_USED/INTEL_PGBYTES);
+                          
+       time_data64 = time_data32;                      /* if no 64-bit commpage, point to 32-bit */
+
+       if (_cpu_capabilities & k64Bit) {
+               commpage_populate_one(  commpage64_map, 
+                                       &commPagePtr64,
+                                       _COMM_PAGE64_AREA_USED,
+                                       _COMM_PAGE32_START_ADDRESS, /* because kernel is built 32-bit */
+                                       commpage_64_routines, 
+                                       FALSE,          /* not a legacy commpage */
+                                       &time_data64,
+                                       "commpage 64-bit");
+               pmap_commpage64_init((vm_offset_t) commPagePtr64, _COMM_PAGE64_BASE_ADDRESS, 
+                                  _COMM_PAGE64_AREA_USED/INTEL_PGBYTES);
+       }
+
+       rtc_nanotime_init_commpage();
+}
+
+
+/* Update commpage nanotime information.  Note that we interleave
+ * setting the 32- and 64-bit commpages, in order to keep nanotime more
+ * nearly in sync between the two environments.
+ *
+ * This routine must be serialized by some external means, ie a lock.
+ */
+
+void
+commpage_set_nanotime(
+       uint64_t        tsc_base,
+       uint64_t        ns_base,
+       uint32_t        scale,
+       uint32_t        shift )
+{
+       commpage_time_data      *p32 = time_data32;
+       commpage_time_data      *p64 = time_data64;
+       static uint32_t generation = 0;
+       uint32_t        next_gen;
+       
+       if (p32 == NULL)                /* have commpages been allocated yet? */
+               return;
+               
+       if ( generation != p32->nt_generation )
+               panic("nanotime trouble 1");    /* possibly not serialized */
+       if ( ns_base < p32->nt_ns_base )
+               panic("nanotime trouble 2");
+       if ((shift != 32) && ((_cpu_capabilities & kSlow)==0) )
+               panic("nanotime trouble 3");
+               
+       next_gen = ++generation;
+       if (next_gen == 0)
+               next_gen = ++generation;
+       
+       p32->nt_generation = 0;         /* mark invalid, so commpage won't try to use it */
+       p64->nt_generation = 0;
+       
+       p32->nt_tsc_base = tsc_base;
+       p64->nt_tsc_base = tsc_base;
+       
+       p32->nt_ns_base = ns_base;
+       p64->nt_ns_base = ns_base;
+       
+       p32->nt_scale = scale;
+       p64->nt_scale = scale;
+       
+       p32->nt_shift = shift;
+       p64->nt_shift = shift;
+       
+       p32->nt_generation = next_gen;  /* mark data as valid */
+       p64->nt_generation = next_gen;
+}
+
+
+/* Disable commpage gettimeofday(), forcing commpage to call through to the kernel.  */
+
+void
+commpage_disable_timestamp( void )
+{
+       time_data32->gtod_generation = 0;
+       time_data64->gtod_generation = 0;
+}
+
+
+/* Update commpage gettimeofday() information.  As with nanotime(), we interleave
+ * updates to the 32- and 64-bit commpage, in order to keep time more nearly in sync 
+ * between the two environments.
+ *
+ * This routine must be serializeed by some external means, ie a lock.
+ */
+ void
+ commpage_set_timestamp(
+       uint64_t        abstime,
+       uint64_t        secs )
+{
+       commpage_time_data      *p32 = time_data32;
+       commpage_time_data      *p64 = time_data64;
+       static uint32_t generation = 0;
+       uint32_t        next_gen;
+       
+       next_gen = ++generation;
+       if (next_gen == 0)
+               next_gen = ++generation;
+       
+       p32->gtod_generation = 0;               /* mark invalid, so commpage won't try to use it */
+       p64->gtod_generation = 0;
+       
+       p32->gtod_ns_base = abstime;
+       p64->gtod_ns_base = abstime;
+       
+       p32->gtod_sec_base = secs;
+       p64->gtod_sec_base = secs;
+       
+       p32->gtod_generation = next_gen;        /* mark data as valid */
+       p64->gtod_generation = next_gen;
 }