osfmk/mach/arm/syscall_sw.h

   1 /*
   2  * Copyright (c) 2007 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  * FILE_ID: syscall_sw.h
  30  */
  31
  32 #ifndef _MACH_ARM_SYSCALL_SW_H_
  33 #define _MACH_ARM_SYSCALL_SW_H_
  34
  35 #if defined(__arm__)
  36
  37 #include <mach/machine/vm_param.h>
  38 #include <architecture/arm/asm_help.h>
  39
  40 /* 0 to 4 args are already loaded in r0-r3 */
  41 #define _kernel_trap_0to4(trap_name, trap_number) \
  42         mov             r12, # ## trap_number                   /* load syscall number */ ; \
  43         swi             #SWI_SYSCALL                                    ; \
  44         bx              lr                                                              /* return */ ;
  45
  46 #define _kernel_trap_5(trap_name, trap_number) \
  47         mov             ip, sp                                                  /* save pointer to args */ ; \
  48         stmfd   sp!, { r4-r5 }                                  /* save r4-r5, keep stack 64-bit aligned */; \
  49         ldr             r4, [ ip ]                                              /* load arg 5 */ ; \
  50         mov             r12, # ## trap_number                   /* load syscall number */ ; \
  51         swi             #SWI_SYSCALL                                    ; \
  52         ldmfd   sp!, { r4-r5 }                                  /* restore r4-r5 */ ;\
  53         bx              lr                                                              /* return */ ;
  54
  55 #define _kernel_trap_6to9(trap_name, trap_number, save_regs, arg_regs) \
  56         mov             ip, sp                                                  /* save pointer to args */ ; \
  57         stmfd   sp!, { save_regs }                              /* callee saved regs */; \
  58         ldmia   ip, { arg_regs }                                /* load arg registers (above r0-r3) */ ;\
  59         mov             r12, # ## trap_number                   /* load syscall number */ ; \
  60         swi             #SWI_SYSCALL                                    ; \
  61         ldmfd   sp!, { save_regs }                              /* restore callee saved regs */ ;\
  62         bx              lr                                                              /* return */ ;
  63
  64 #define COMMA ,
  65
  66 /* For the armv7k ABI, the alignment requirements may add padding. So we
  67  * let the kernel figure it out and push extra on the stack to avoid un-needed
  68  * copy-ins. We are relying on arguments that aren't in registers starting
  69  * 32 bytes from sp.  */
  70 #if __BIGGEST_ALIGNMENT__ > 4
  71
  72 #define _kernel_trap_0(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  73 #define _kernel_trap_1(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  74 #define _kernel_trap_2(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  75 #define _kernel_trap_3(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  76 #define _kernel_trap_4(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r5, r4-r5)
  77 #undef _kernel_trap_5
  78 #define _kernel_trap_5(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r5, r4-r5)
  79 #define _kernel_trap_6(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r6 COMMA r8, r4-r6 COMMA r8)
  80 #define _kernel_trap_7(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r6 COMMA r8, r4-r6 COMMA r8)
  81 #define _kernel_trap_8(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r6 COMMA r8, r4-r6 COMMA r8)
  82 #define _kernel_trap_9(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r6 COMMA r8, r4-r6 COMMA r8)
  83 #else // !(__BIGGEST_ALIGNMENT__ > 4)
  84
  85 #define _kernel_trap_0(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  86 #define _kernel_trap_1(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  87 #define _kernel_trap_2(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  88 #define _kernel_trap_3(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  89 #define _kernel_trap_4(trap_name, trap_number) _kernel_trap_0to4(trap_name, trap_number)
  90 /* _kernel_trap_5 defined above */
  91 #define _kernel_trap_6(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r5, r4-r5)
  92 /* need to save r8 not just for alignment but because mach_msg_trap overwrites the eighth argument */
  93 #define _kernel_trap_7(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r6 COMMA r8, r4-r6)
  94 #define _kernel_trap_8(trap_name, trap_number) _kernel_trap_6to9(trap_name, trap_number, r4-r6 COMMA r8, r4-r6 COMMA r8)
  95 /* there is only one nine-argument trap (mach_msg_overwrite_trap) and it doesn't use the ninth argument */
  96 #define _kernel_trap_9(trap_name, trap_number) _kernel_trap_8(trap_name, trap_number)
  97
  98 #endif // __BIGGEST_ALIGNMENT__ > 4
  99
 100
 101 /* select the appropriate trap macro based off the number of args */
 102 #define kernel_trap(trap_name, trap_number, num_args) \
 103         LEAF(_##trap_name, 0)   \
 104         _kernel_trap_##num_args(trap_name, trap_number)
 105
 106 #elif defined(__arm64__)
 107
 108 #include <mach/machine/vm_param.h>
 109
 110 #define kernel_trap(trap_name, trap_number, num_args) \
 111 .globl _##trap_name                                           %% \
 112 .text                                                         %% \
 113 .align  2                                                     %% \
 114 _##trap_name:                                                 %% \
 115     mov x16, #(trap_number)                                   %% \
 116     svc #SWI_SYSCALL                                          %% \
 117     ret
 118
 119 #else
 120 #error Unsupported architecture
 121 #endif
 122
 123 #endif  /* _MACH_ARM_SYSCALL_SW_H_ */