osfmk/arm64/pac_asm.h

   1 /*
   2  * Copyright (c) 2019 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 _ARM64_PAC_ASM_H_
  30 #define _ARM64_PAC_ASM_H_
  31
  32 #ifndef __ASSEMBLER__
  33 #error "This header should only be used in .s files"
  34 #endif
  35
  36 #include <pexpert/arm64/board_config.h>
  37 #include <arm64/proc_reg.h>
  38 #include "assym.s"
  39
  40 #if defined(HAS_APPLE_PAC)
  41
  42 #if defined(APPLEFIRESTORM)
  43 /* H13 may use either fast or slow A-key switching, depending on CPU model and revision */
  44 #define HAS_PAC_FAST_A_KEY_SWITCHING    1
  45 #define HAS_PAC_SLOW_A_KEY_SWITCHING    1
  46
  47 /* BEGIN IGNORE CODESTYLE */
  48
  49 /**
  50  * IF_PAC_FAST_A_KEY_SWITCHING
  51  *
  52  * Branch to a specified label if this H13 model + revision supports fast A-key switching.
  53  *
  54  *   label - label to branch to
  55  *   tmp - scratch register
  56  */
  57 .macro IF_PAC_FAST_A_KEY_SWITCHING      label, tmp
  58         /**
  59          * start.s attempts to set APCTL_EL1.UserKeyEn.  If this H13 CPU doesn't
  60          * actually support this bit, it will be RaZ.
  61          */
  62         mrs             \tmp, APCTL_EL1
  63         tbnz    \tmp, #APCTL_EL1_UserKeyEn_OFFSET, \label
  64 .endmacro
  65
  66 /**
  67  * IF_PAC_SLOW_A_KEY_SWITCHING
  68  *
  69  * Branch to a specified label if this H13 model + revision doesn't support fast A-key switching.
  70  *
  71  *   label - label to branch to
  72  *   tmp - scratch register
  73  */
  74 .macro IF_PAC_SLOW_A_KEY_SWITCHING      label, tmp
  75         mrs             \tmp, APCTL_EL1
  76         tbz             \tmp, #APCTL_EL1_UserKeyEn_OFFSET, \label
  77 .endmacro
  78
  79 /* END IGNORE CODESTYLE */
  80
  81 #elif defined(HAS_APCTL_EL1_USERKEYEN)
  82 #define HAS_PAC_FAST_A_KEY_SWITCHING    1
  83 #define HAS_PAC_SLOW_A_KEY_SWITCHING    0
  84
  85 .macro IF_PAC_FAST_A_KEY_SWITCHING      label, tmp
  86 .error "This macro should never need to be used on this CPU family."
  87 .endmacro
  88
  89 /* We know at compile time that this CPU family definitely doesn't need slow A-key switching */
  90 .macro IF_PAC_SLOW_A_KEY_SWITCHING      label, tmp
  91 .endmacro
  92
  93 #else /* !defined(APPLEFIRESTORM) && !defined(HAS_APCTL_EL1_USERKEYEN) */
  94 #define HAS_PAC_FAST_A_KEY_SWITCHING    0
  95 #define HAS_PAC_SLOW_A_KEY_SWITCHING    1
  96
  97 /* We know at compile time that this CPU family definitely doesn't support fast A-key switching */
  98 .macro IF_PAC_FAST_A_KEY_SWITCHING      label, tmp
  99 .endmacro
 100
 101 .macro IF_PAC_SLOW_A_KEY_SWITCHING      label, tmp
 102 .error "This macro should never need to be used on this CPU family."
 103 .endmacro
 104
 105 #endif /* defined(APPLEFIRESTORM) */
 106
 107 /* BEGIN IGNORE CODESTYLE */
 108
 109 /**
 110  * REPROGRAM_JOP_KEYS
 111  *
 112  * Reprograms the A-key registers if needed, and updates current_cpu_datap()->jop_key.
 113  *
 114  * On CPUs where fast A-key switching is implemented, this macro reprograms KERNKey_EL1.
 115  * On other CPUs, it reprograms AP{D,I}AKey_EL1.
 116  *
 117  *   skip_label - branch to this label if new_jop_key is already loaded into CPU
 118  *   new_jop_key - new APIAKeyLo value
 119  *   cpudatap - current cpu_data_t *
 120  *   tmp - scratch register
 121  */
 122 .macro REPROGRAM_JOP_KEYS       skip_label, new_jop_key, cpudatap, tmp
 123         ldr             \tmp, [\cpudatap, CPU_JOP_KEY]
 124         cmp             \new_jop_key, \tmp
 125         b.eq    \skip_label
 126         SET_JOP_KEY_REGISTERS   \new_jop_key, \tmp
 127         str             \new_jop_key, [\cpudatap, CPU_JOP_KEY]
 128 .endmacro
 129
 130 /**
 131  * SET_JOP_KEY_REGISTERS
 132  *
 133  * Unconditionally reprograms the A-key registers.  The caller is responsible for
 134  * updating current_cpu_datap()->jop_key as needed.
 135  *
 136  *   new_jop_key - new APIAKeyLo value
 137  *   tmp - scratch register
 138  */
 139 .macro SET_JOP_KEY_REGISTERS    new_jop_key, tmp
 140 #if HAS_PAC_FAST_A_KEY_SWITCHING
 141         IF_PAC_SLOW_A_KEY_SWITCHING     Lslow_reprogram_jop_keys_\@, \tmp
 142         msr             KERNKeyLo_EL1, \new_jop_key
 143         add             \tmp, \new_jop_key, #1
 144         msr             KERNKeyHi_EL1, \tmp
 145 #endif /* HAS_PAC_FAST_A_KEY_SWITCHING */
 146 #if HAS_PAC_FAST_A_KEY_SWITCHING && HAS_PAC_SLOW_A_KEY_SWITCHING
 147         b               Lset_jop_key_registers_done_\@
 148 #endif /* HAS_PAC_FAST_A_KEY_SWITCHING && HAS_PAC_SLOW_A_KEY_SWITCHING */
 149
 150 #if HAS_PAC_SLOW_A_KEY_SWITCHING
 151 Lslow_reprogram_jop_keys_\@:
 152         msr             APIAKeyLo_EL1, \new_jop_key
 153         add             \tmp, \new_jop_key, #1
 154         msr             APIAKeyHi_EL1, \tmp
 155         add             \tmp, \tmp, #1
 156         msr             APDAKeyLo_EL1, \tmp
 157         add             \tmp, \tmp, #1
 158         msr             APDAKeyHi_EL1, \tmp
 159 #endif /* HAS_PAC_SLOW_A_KEY_SWITCHING */
 160
 161 Lset_jop_key_registers_done_\@:
 162 .endmacro
 163
 164 /* END IGNORE CODESTYLE */
 165
 166 #endif /* defined(HAS_APPLE_PAC) */
 167
 168 #endif /* _ARM64_PAC_ASM_H_ */
 169
 170 /* vim: set ts=4 ft=asm: */