osfmk/i386/commpage/commpage.h

   1 /*
   2  * Copyright (c) 2003-2009 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28
  29 #ifndef _I386_COMMPAGE_H
  30 #define _I386_COMMPAGE_H
  31
  32 #ifndef __ASSEMBLER__
  33 #include <stdint.h>
  34 #include <mach/boolean.h>
  35 #include <mach/vm_types.h>
  36 #include <machine/cpu_capabilities.h>
  37 #endif /* __ASSEMBLER__ */
  38
  39 /* When trying to acquire a spinlock or mutex, we will spin in
  40  * user mode for awhile, before entering the kernel to relinquish.
  41  * MP_SPIN_TRIES is the initial value of _COMM_PAGE_SPIN_COUNT.
  42  * The idea is that _COMM_PAGE_SPIN_COUNT will be adjusted up or
  43  * down as the machine is plugged in/out, etc.
  44  * At present spinlocks do not use _COMM_PAGE_SPIN_COUNT.
  45  * They use MP_SPIN_TRIES directly.
  46  */
  47 #define MP_SPIN_TRIES   1000
  48
  49
  50 /* The following macro is used to generate the 64-bit commpage address for a given
  51  * routine, based on its 32-bit address.  This is used in the kernel to compile
  52  * the 64-bit commpage.  Since the kernel can be a 32-bit object, cpu_capabilities.h
  53  * only defines the 32-bit address.
  54  */
  55 #define _COMM_PAGE_32_TO_64( ADDRESS )  ( ADDRESS + _COMM_PAGE64_START_ADDRESS - _COMM_PAGE32_START_ADDRESS )
  56
  57
  58 #ifdef  __ASSEMBLER__
  59
  60 #define COMMPAGE_DESCRIPTOR_NAME(label)  _commpage_ ## label
  61
  62 #if defined (__i386__)
  63
  64 #define COMMPAGE_DESCRIPTOR_FIELD_POINTER .long
  65 #define COMMPAGE_DESCRIPTOR_REFERENCE(label) \
  66         .long COMMPAGE_DESCRIPTOR_NAME(label)
  67
  68 #elif defined (__x86_64__)
  69
  70 #define COMMPAGE_DESCRIPTOR_FIELD_POINTER .quad
  71 #define COMMPAGE_DESCRIPTOR_REFERENCE(label) \
  72         .quad COMMPAGE_DESCRIPTOR_NAME(label)
  73
  74 #else
  75 #error unsupported architecture
  76 #endif
  77
  78 #define COMMPAGE_FUNCTION_START(label,codetype,alignment) \
  79 .text                                                           ;\
  80 .code ## codetype                                               ;\
  81 .align alignment, 0x90                                          ;\
  82 L ## label ## :
  83
  84 #define COMMPAGE_DESCRIPTOR(label,address,must,cant)    \
  85 L ## label ## _end:                                             ;\
  86 .set L ## label ## _size, L ## label ## _end - L ## label       ;\
  87 .const_data                                                     ;\
  88 .private_extern COMMPAGE_DESCRIPTOR_NAME(label)                 ;\
  89 COMMPAGE_DESCRIPTOR_NAME(label) ## :                            ;\
  90     COMMPAGE_DESCRIPTOR_FIELD_POINTER   L ## label              ;\
  91     .long                               L ## label ## _size     ;\
  92     .long                               address                 ;\
  93     .long                               must                    ;\
  94     .long                               cant                    ;\
  95 .text
  96
  97
  98 /* COMMPAGE_CALL(target,from,start)
  99  *
 100  * This macro compiles a relative near call to one
 101  * commpage routine from another.
 102  * The assembler cannot handle this directly because the code
 103  * is not being assembled at the address at which it will execute.
 104  * The alternative to this macro would be to use an
 105  * indirect call, which is slower because the target of an
 106  * indirect branch is poorly predicted.
 107  * The macro arguments are:
 108  *      target = the commpage routine we are calling
 109  *      from   = the commpage routine we are in now
 110  *      start  = the label at the start of the code for this func
 111  * This is admitedly ugly and fragile.  Is there a better way?
 112  */
 113 #define COMMPAGE_CALL(target,from,start)                        \
 114         COMMPAGE_CALL_INTERNAL(target,from,start,__LINE__)
 115
 116 #define COMMPAGE_CALL_INTERNAL(target,from,start,unique)        \
 117         .byte 0xe8                                              ;\
 118 .set UNIQUEID(unique), L ## start - . + target - from - 4       ;\
 119         .long   UNIQUEID(unique)
 120
 121 #define UNIQUEID(name)  L ## name
 122
 123 #else /* __ASSEMBLER__ */
 124
 125 /* Each potential commpage routine is described by one of these.
 126  * Note that the COMMPAGE_DESCRIPTOR macro (above), used in
 127  * assembly language, must agree with this.
 128  */
 129
 130 typedef struct  commpage_descriptor     {
 131     void                *code_address;                          // address of code
 132     uint32_t            code_length;                            // length in bytes
 133     uint32_t            commpage_address;                       // put at this address (_COMM_PAGE_BCOPY etc)
 134     uint32_t            musthave;                               // _cpu_capability bits we must have
 135     uint32_t            canthave;                               // _cpu_capability bits we can't have
 136 } commpage_descriptor;
 137
 138
 139 /* Warning: following structure must match the layout of the commpage.  */
 140 /* This is the data starting at _COMM_PAGE_TIME_DATA_START, ie for nanotime() and gettimeofday() */
 141
 142 typedef volatile struct commpage_time_data      {
 143         uint64_t        nt_tsc_base;                            // _COMM_PAGE_NT_TSC_BASE
 144         uint32_t        nt_scale;                               // _COMM_PAGE_NT_SCALE
 145         uint32_t        nt_shift;                               // _COMM_PAGE_NT_SHIFT
 146         uint64_t        nt_ns_base;                             // _COMM_PAGE_NT_NS_BASE
 147         uint32_t        nt_generation;                          // _COMM_PAGE_NT_GENERATION
 148         uint32_t        gtod_generation;                        // _COMM_PAGE_GTOD_GENERATION
 149         uint64_t        gtod_ns_base;                           // _COMM_PAGE_GTOD_NS_BASE
 150         uint64_t        gtod_sec_base;                          // _COMM_PAGE_GTOD_SEC_BASE
 151 } commpage_time_data;
 152
 153
 154 extern  char    *commPagePtr32;                         // virt address of 32-bit commpage in kernel map
 155 extern  char    *commPagePtr64;                         // ...and of 64-bit commpage
 156
 157 extern  void    commpage_set_timestamp(uint64_t abstime, uint64_t secs);
 158 extern  void    commpage_disable_timestamp( void );
 159 extern  void    commpage_set_nanotime(uint64_t tsc_base, uint64_t ns_base, uint32_t scale, uint32_t shift);
 160 extern  void    commpage_set_memory_pressure(unsigned int  pressure);
 161 extern  void    commpage_set_spin_count(unsigned int  count);
 162 extern  void    commpage_sched_gen_inc(void);
 163
 164 extern  uint32_t        commpage_is_in_pfz32(uint32_t);
 165 extern  uint32_t        commpage_is_in_pfz64(addr64_t);
 166
 167 #endif  /* __ASSEMBLER__ */
 168
 169 #endif /* _I386_COMMPAGE_H */