]> git.saurik.com Git - apple/xnu.git/blobdiff - osfmk/i386/commpage/commpage.c
xnu-1699.22.73.tar.gz
[apple/xnu.git] / osfmk / i386 / commpage / commpage.c
index 8bf520d633feb06acb652a0490f324131351d308..cc52576c5bf3ebfc0a5452ad05f324065f5802c2 100644 (file)
@@ -1,60 +1,99 @@
 /*
- * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003-2010 Apple Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * 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. 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.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * 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
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * 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 <mach/mach_vm.h>
+#include <mach/machine.h>
+#include <i386/cpuid.h>
+#include <i386/tsc.h>
+#include <i386/rtclock_protos.h>
+#include <i386/cpu_data.h>
 #include <i386/machine_routines.h>
+#include <i386/misc_protos.h>
+#include <i386/cpuid.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>
+#include <kern/processor.h>
+
+/* the lists of commpage routines are in commpage_asm.s  */
+extern commpage_descriptor*    commpage_32_routines[];
+extern commpage_descriptor*    commpage_64_routines[];
+
+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
+uint32_t     _cpu_capabilities = 0;          // define the capability vector
 
-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
+int    noVMX = 0;              /* if true, do not set kHasAltivec in ppc _cpu_capabilities */
 
-int     _cpu_capabilities = 0;          // define the capability vector
+typedef uint32_t commpage_address_t;
 
-char    *commPagePtr = NULL;            // virtual address of comm page in kernel map
+static commpage_address_t      next;                   // next available address in comm page
+static commpage_address_t      cur_routine;            // comm page address of "current" routine
+static boolean_t               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 commpage_address_t      commPageBaseOffset; // subtract from 32-bit runtime address to get offset in virtual commpage in kernel map
+
+static commpage_time_data      *time_data32 = NULL;
+static commpage_time_data      *time_data64 = NULL;
+
+decl_simple_lock_data(static,commpage_active_cpus_lock);
 
 /* Allocate the commpage and add to the shared submap created by vm:
  *     1. allocate a page in the kernel map (RW)
@@ -64,56 +103,77 @@ 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);
+       
+       // Initialize the text section of the commpage with INT3
+       char *commpage_ptr = (char*)(intptr_t)kernel_addr;
+       vm_size_t i;
+       for( i = _COMM_PAGE_TEXT_START - _COMM_PAGE_START_ADDRESS; i < size; i++ )
+               // This is the hex for the X86 opcode INT3
+               commpage_ptr[i] = 0xCC;
+
+       return (void*)(intptr_t)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 )
+    commpage_address_t     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
@@ -139,7 +199,7 @@ commpage_cpus( void )
 static void
 commpage_init_cpu_capabilities( void )
 {
-       int bits;
+       uint32_t bits;
        int cpus;
        ml_cpu_info_t cpu_info;
 
@@ -147,8 +207,20 @@ commpage_init_cpu_capabilities( void )
        ml_cpu_get_info(&cpu_info);
        
        switch (cpu_info.vector_unit) {
+               case 9:
+                       bits |= kHasAVX1_0;
+                       /* fall thru */
+               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;
@@ -181,25 +253,42 @@ 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;
+
+       if (cpuid_features() & CPUID_FEATURE_AES)
+               bits |= kHasAES;
+
        _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,
+    commpage_address_t         address,
+    const void         *source,
     int        length  )
 {    
     void       *dest = commpage_addr_of(address);
     
-    if ((uintptr_t)dest < next)
-        panic("commpage overlap");
+    if (address < next)
+       panic("commpage overlap at address 0x%p, 0x%x < 0x%x", dest, address, next);
     
     bcopy(source,dest,length);
     
-    next = ((uintptr_t)dest + length);
+    next = address + length;
 }
 
 /* Copy a routine into comm page if it matches running machine.
@@ -208,11 +297,11 @@ static void
 commpage_stuff_routine(
     commpage_descriptor        *rd     )
 {
-    int                must,cant;
+    uint32_t           must,cant;
     
     if (rd->commpage_address != cur_routine) {
         if ((cur_routine!=0) && (matched==0))
-            panic("commpage no match");
+            panic("commpage no match for last, next address %08x", rd->commpage_address);
         cur_routine = rd->commpage_address;
         matched = 0;
     }
@@ -222,104 +311,330 @@ commpage_stuff_routine(
     
     if ((must == rd->musthave) && (cant == 0)) {
         if (matched)
-            panic("commpage duplicate matches");
+            panic("commpage multiple matches for address %08x", 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.
  */
 
-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
+       commpage_address_t base_offset, // will become commPageBaseOffset
+       commpage_descriptor** commpage_routines, // list of routine ptrs for this commpage
+       commpage_time_data** time_data, // &time_data32 or &time_data64
+       const char*     signature )     // "commpage 32-bit" or "commpage 64-bit"
 {
+       uint8_t c1;
+       short   c2;
+       int         c4;
+       uint64_t c8;
+       uint32_t        cfamily;
        commpage_descriptor **rd;
        short   version = _COMM_PAGE_THIS_VERSION;
-       void    *sig_addr;
 
-       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();
+       next = 0;
+       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;
 
-       commpage_init_cpu_capabilities();
+       *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,(int)strlen(signature));
        commpage_stuff(_COMM_PAGE_VERSION,&version,sizeof(short));
-       commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,
-               sizeof(int));
+       commpage_stuff(_COMM_PAGE_CPU_CAPABILITIES,&_cpu_capabilities,sizeof(int));
+
+       c2 = 32;  // default
+       if (_cpu_capabilities & kCache64)
+               c2 = 64;
+       else if (_cpu_capabilities & kCache128)
+               c2 = 128;
+       commpage_stuff(_COMM_PAGE_CACHE_LINESIZE,&c2,2);
+       
+       c4 = MP_SPIN_TRIES;
+       commpage_stuff(_COMM_PAGE_SPIN_COUNT,&c4,4);
+
+       /* machine_info valid after ml_get_max_cpus() */
+       c1 = machine_info.physical_cpu_max;
+       commpage_stuff(_COMM_PAGE_PHYSICAL_CPUS,&c1,1);
+       c1 = machine_info.logical_cpu_max;
+       commpage_stuff(_COMM_PAGE_LOGICAL_CPUS,&c1,1);
+
+       c8 = ml_cpu_cache_size(0);
+       commpage_stuff(_COMM_PAGE_MEMORY_SIZE, &c8, 8);
+
+       cfamily = cpuid_info()->cpuid_cpufamily;
+       commpage_stuff(_COMM_PAGE_CPUFAMILY, &cfamily, 4);
 
-       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 > _COMM_PAGE_END)
+               panic("commpage overflow: next = 0x%08x, commPagePtr = 0x%p", next, commPagePtr);
+
 }
+
+
+/* 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, 
+                               &time_data32,
+                               "commpage 32-bit");
+#ifndef __LP64__
+       pmap_commpage32_init((vm_offset_t) commPagePtr32, _COMM_PAGE32_BASE_ADDRESS, 
+                          _COMM_PAGE32_AREA_USED/INTEL_PGBYTES);
+#endif                    
+       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, /* commpage address are relative to 32-bit commpage placement */
+                                       commpage_64_routines, 
+                                       &time_data64,
+                                       "commpage 64-bit");
+#ifndef __LP64__
+               pmap_commpage64_init((vm_offset_t) commPagePtr64, _COMM_PAGE64_BASE_ADDRESS, 
+                                  _COMM_PAGE64_AREA_USED/INTEL_PGBYTES);
+#endif
+       }
+
+       simple_lock_init(&commpage_active_cpus_lock, 0);
+
+       commpage_update_active_cpus();
+       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;
+}
+
+
+/* Update _COMM_PAGE_MEMORY_PRESSURE.  Called periodically from vm's compute_memory_pressure()  */
+
+void
+commpage_set_memory_pressure(
+       unsigned int    pressure )
+{
+       char        *cp;
+       uint32_t    *ip;
+       
+       cp = commPagePtr32;
+       if ( cp ) {
+               cp += (_COMM_PAGE_MEMORY_PRESSURE - _COMM_PAGE32_BASE_ADDRESS);
+               ip = (uint32_t*) cp;
+               *ip = (uint32_t) pressure;
+       }
+       
+       cp = commPagePtr64;
+       if ( cp ) {
+               cp += (_COMM_PAGE_MEMORY_PRESSURE - _COMM_PAGE32_START_ADDRESS);
+               ip = (uint32_t*) cp;
+               *ip = (uint32_t) pressure;
+       }
+
+}
+
+
+/* Update _COMM_PAGE_SPIN_COUNT.  We might want to reduce when running on a battery, etc. */
+
+void
+commpage_set_spin_count(
+       unsigned int    count )
+{
+       char        *cp;
+       uint32_t    *ip;
+       
+       if (count == 0)     /* we test for 0 after decrement, not before */
+           count = 1;
+           
+       cp = commPagePtr32;
+       if ( cp ) {
+               cp += (_COMM_PAGE_SPIN_COUNT - _COMM_PAGE32_BASE_ADDRESS);
+               ip = (uint32_t*) cp;
+               *ip = (uint32_t) count;
+       }
+       
+       cp = commPagePtr64;
+       if ( cp ) {
+               cp += (_COMM_PAGE_SPIN_COUNT - _COMM_PAGE32_START_ADDRESS);
+               ip = (uint32_t*) cp;
+               *ip = (uint32_t) count;
+       }
+
+}
+
+/* Updated every time a logical CPU goes offline/online */
+void
+commpage_update_active_cpus(void)
+{
+       char        *cp;
+       volatile uint8_t    *ip;
+       
+       /* At least 32-bit commpage must be initialized */
+       if (!commPagePtr32)
+               return;
+
+       simple_lock(&commpage_active_cpus_lock);
+
+       cp = commPagePtr32;
+       cp += (_COMM_PAGE_ACTIVE_CPUS - _COMM_PAGE32_BASE_ADDRESS);
+       ip = (volatile uint8_t*) cp;
+       *ip = (uint8_t) processor_avail_count;
+       
+       cp = commPagePtr64;
+       if ( cp ) {
+               cp += (_COMM_PAGE_ACTIVE_CPUS - _COMM_PAGE32_START_ADDRESS);
+               ip = (volatile uint8_t*) cp;
+               *ip = (uint8_t) processor_avail_count;
+       }
+
+       simple_unlock(&commpage_active_cpus_lock);
+}
+
+
+/* Check to see if a given address is in the Preemption Free Zone (PFZ) */
+
+uint32_t
+commpage_is_in_pfz32(uint32_t addr32)
+{
+       if ( (addr32 >= _COMM_PAGE_PFZ_START) && (addr32 < _COMM_PAGE_PFZ_END)) {
+               return 1;
+       }
+       else
+               return 0;
+}
+
+uint32_t
+commpage_is_in_pfz64(addr64_t addr64)
+{
+       if ( (addr64 >= _COMM_PAGE_32_TO_64(_COMM_PAGE_PFZ_START))
+            && (addr64 <  _COMM_PAGE_32_TO_64(_COMM_PAGE_PFZ_END))) {
+               return 1;
+       }
+       else
+               return 0;
+}
+