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(HAS_APCTL_EL1_USERKEYEN)
  43 #define HAS_PAC_FAST_A_KEY_SWITCHING    1
  44 #define HAS_PAC_SLOW_A_KEY_SWITCHING    0
  45
  46 .macro IF_PAC_FAST_A_KEY_SWITCHING      label, tmp
  47 .error "This macro should never need to be used on this CPU family."
  48 .endmacro
  49
  50 /* We know at compile time that this CPU family definitely doesn't need slow A-key switching */
  51 .macro IF_PAC_SLOW_A_KEY_SWITCHING      label, tmp
  52 .endmacro
  53
  54 #else /* !&& !defined(HAS_APCTL_EL1_USERKEYEN) */
  55 #define HAS_PAC_FAST_A_KEY_SWITCHING    0
  56 #define HAS_PAC_SLOW_A_KEY_SWITCHING    1
  57
  58 /* We know at compile time that this CPU family definitely doesn't support fast A-key switching */
  59 .macro IF_PAC_FAST_A_KEY_SWITCHING      label, tmp
  60 .endmacro
  61
  62 .macro IF_PAC_SLOW_A_KEY_SWITCHING      label, tmp
  63 .error "This macro should never need to be used on this CPU family."
  64 .endmacro
  65
  66 #endif /**/
  67
  68 /* BEGIN IGNORE CODESTYLE */
  69
  70 /**
  71  * REPROGRAM_JOP_KEYS
  72  *
  73  * Reprograms the A-key registers if needed, and updates current_cpu_datap()->jop_key.
  74  *
  75  * On CPUs where fast A-key switching is implemented, this macro reprograms KERNKey_EL1.
  76  * On other CPUs, it reprograms AP{D,I}AKey_EL1.
  77  *
  78  *   skip_label - branch to this label if new_jop_key is already loaded into CPU
  79  *   new_jop_key - new APIAKeyLo value
  80  *   cpudatap - current cpu_data_t *
  81  *   tmp - scratch register
  82  */
  83 .macro REPROGRAM_JOP_KEYS       skip_label, new_jop_key, cpudatap, tmp
  84         ldr             \tmp, [\cpudatap, CPU_JOP_KEY]
  85         cmp             \new_jop_key, \tmp
  86         b.eq    \skip_label
  87         SET_JOP_KEY_REGISTERS   \new_jop_key, \tmp
  88         str             \new_jop_key, [\cpudatap, CPU_JOP_KEY]
  89 .endmacro
  90
  91 /**
  92  * SET_JOP_KEY_REGISTERS
  93  *
  94  * Unconditionally reprograms the A-key registers.  The caller is responsible for
  95  * updating current_cpu_datap()->jop_key as needed.
  96  *
  97  *   new_jop_key - new APIAKeyLo value
  98  *   tmp - scratch register
  99  */
 100 .macro SET_JOP_KEY_REGISTERS    new_jop_key, tmp
 101 #if HAS_PAC_FAST_A_KEY_SWITCHING
 102         IF_PAC_SLOW_A_KEY_SWITCHING     Lslow_reprogram_jop_keys_\@, \tmp
 103         msr             KERNKeyLo_EL1, \new_jop_key
 104         add             \tmp, \new_jop_key, #1
 105         msr             KERNKeyHi_EL1, \tmp
 106 #endif /* HAS_PAC_FAST_A_KEY_SWITCHING */
 107 #if HAS_PAC_FAST_A_KEY_SWITCHING && HAS_PAC_SLOW_A_KEY_SWITCHING
 108         b               Lset_jop_key_registers_done_\@
 109 #endif /* HAS_PAC_FAST_A_KEY_SWITCHING && HAS_PAC_SLOW_A_KEY_SWITCHING */
 110
 111 #if HAS_PAC_SLOW_A_KEY_SWITCHING
 112 Lslow_reprogram_jop_keys_\@:
 113         msr             APIAKeyLo_EL1, \new_jop_key
 114         add             \tmp, \new_jop_key, #1
 115         msr             APIAKeyHi_EL1, \tmp
 116         add             \tmp, \tmp, #1
 117         msr             APDAKeyLo_EL1, \tmp
 118         add             \tmp, \tmp, #1
 119         msr             APDAKeyHi_EL1, \tmp
 120 #endif /* HAS_PAC_SLOW_A_KEY_SWITCHING */
 121
 122 Lset_jop_key_registers_done_\@:
 123 .endmacro
 124
 125 /* END IGNORE CODESTYLE */
 126
 127 #endif /* defined(HAS_APPLE_PAC) */
 128
 129 #endif /* _ARM64_PAC_ASM_H_ */
 130
 131 /* vim: set ts=4 ft=asm: */