linux-user/ppc/vdso.S

   1 /*
   2  * PowerPC linux replacement vdso.
   3  *
   4  * Copyright 2023 Linaro, Ltd.
   5  *
   6  * SPDX-License-Identifier: GPL-2.0-or-later
   7  */
   8
   9 #include <asm/unistd.h>
  10 #include <asm/errno.h>
  11
  12 #ifndef _ARCH_PPC64
  13 # define TARGET_ABI32
  14 #endif
  15 #include "vdso-asmoffset.h"
  16
  17
  18         .text
  19
  20 .macro endf name
  21         .globl  \name
  22         .size   \name, .-\name
  23         /* For PPC64, functions have special linkage; we export pointers. */
  24 #ifndef _ARCH_PPC64
  25         .type   \name, @function
  26 #endif
  27 .endm
  28
  29 .macro raw_syscall nr
  30         addi    0, 0, \nr
  31         sc
  32 .endm
  33
  34 .macro vdso_syscall name, nr
  35 \name:
  36         raw_syscall \nr
  37         blr
  38 endf    \name
  39 .endm
  40
  41         .cfi_startproc
  42
  43 vdso_syscall __kernel_gettimeofday, __NR_gettimeofday
  44 vdso_syscall __kernel_clock_gettime, __NR_clock_gettime
  45 vdso_syscall __kernel_clock_getres, __NR_clock_getres
  46 vdso_syscall __kernel_getcpu, __NR_getcpu
  47 vdso_syscall __kernel_time, __NR_time
  48
  49 #ifdef __NR_clock_gettime64
  50 vdso_syscall __kernel_clock_gettime64, __NR_clock_gettime64
  51 #endif
  52
  53 __kernel_sync_dicache:
  54         /* qemu does not need to flush caches */
  55         blr
  56 endf    __kernel_sync_dicache
  57
  58         .cfi_endproc
  59
  60 /*
  61  * TODO: __kernel_get_tbfreq
  62  * This is probably a constant for QEMU.
  63  */
  64
  65 /*
  66  * Start the unwind info at least one instruction before the signal
  67  * trampoline, because the unwinder will assume we are returning
  68  * after a call site.
  69  */
  70
  71         .cfi_startproc simple
  72         .cfi_signal_frame
  73
  74 #ifdef _ARCH_PPC64
  75 # define __kernel_sigtramp_rt  __kernel_sigtramp_rt64
  76 # define sizeof_reg     8
  77 #else
  78 # define __kernel_sigtramp_rt  __kernel_sigtramp_rt32
  79 # define sizeof_reg     4
  80 #endif
  81 #define sizeof_freg     8
  82 #define sizeof_vreg     16
  83
  84         .cfi_def_cfa    1, SIGNAL_FRAMESIZE + offsetof_rt_sigframe_mcontext
  85
  86         /* Return address */
  87         .cfi_return_column 67
  88         .cfi_offset     67, 32 * sizeof_reg             /* nip */
  89
  90         /* Integer registers */
  91         .cfi_offset     0, 0 * sizeof_reg
  92         .cfi_offset     1, 1 * sizeof_reg
  93         .cfi_offset     2, 2 * sizeof_reg
  94         .cfi_offset     3, 3 * sizeof_reg
  95         .cfi_offset     4, 4 * sizeof_reg
  96         .cfi_offset     5, 5 * sizeof_reg
  97         .cfi_offset     6, 6 * sizeof_reg
  98         .cfi_offset     7, 7 * sizeof_reg
  99         .cfi_offset     8, 8 * sizeof_reg
 100         .cfi_offset     9, 9 * sizeof_reg
 101         .cfi_offset     10, 10 * sizeof_reg
 102         .cfi_offset     11, 11 * sizeof_reg
 103         .cfi_offset     12, 12 * sizeof_reg
 104         .cfi_offset     13, 13 * sizeof_reg
 105         .cfi_offset     14, 14 * sizeof_reg
 106         .cfi_offset     15, 15 * sizeof_reg
 107         .cfi_offset     16, 16 * sizeof_reg
 108         .cfi_offset     17, 17 * sizeof_reg
 109         .cfi_offset     18, 18 * sizeof_reg
 110         .cfi_offset     19, 19 * sizeof_reg
 111         .cfi_offset     20, 20 * sizeof_reg
 112         .cfi_offset     21, 21 * sizeof_reg
 113         .cfi_offset     22, 22 * sizeof_reg
 114         .cfi_offset     23, 23 * sizeof_reg
 115         .cfi_offset     24, 24 * sizeof_reg
 116         .cfi_offset     25, 25 * sizeof_reg
 117         .cfi_offset     26, 26 * sizeof_reg
 118         .cfi_offset     27, 27 * sizeof_reg
 119         .cfi_offset     28, 28 * sizeof_reg
 120         .cfi_offset     29, 29 * sizeof_reg
 121         .cfi_offset     30, 30 * sizeof_reg
 122         .cfi_offset     31, 31 * sizeof_reg
 123         .cfi_offset     65, 36 * sizeof_reg             /* lr */
 124         .cfi_offset     70, 38 * sizeof_reg             /* ccr */
 125
 126         /* Floating point registers */
 127         .cfi_offset     32, offsetof_mcontext_fregs
 128         .cfi_offset     33, offsetof_mcontext_fregs + 1 * sizeof_freg
 129         .cfi_offset     34, offsetof_mcontext_fregs + 2 * sizeof_freg
 130         .cfi_offset     35, offsetof_mcontext_fregs + 3 * sizeof_freg
 131         .cfi_offset     36, offsetof_mcontext_fregs + 4 * sizeof_freg
 132         .cfi_offset     37, offsetof_mcontext_fregs + 5 * sizeof_freg
 133         .cfi_offset     38, offsetof_mcontext_fregs + 6 * sizeof_freg
 134         .cfi_offset     39, offsetof_mcontext_fregs + 7 * sizeof_freg
 135         .cfi_offset     40, offsetof_mcontext_fregs + 8 * sizeof_freg
 136         .cfi_offset     41, offsetof_mcontext_fregs + 9 * sizeof_freg
 137         .cfi_offset     42, offsetof_mcontext_fregs + 10 * sizeof_freg
 138         .cfi_offset     43, offsetof_mcontext_fregs + 11 * sizeof_freg
 139         .cfi_offset     44, offsetof_mcontext_fregs + 12 * sizeof_freg
 140         .cfi_offset     45, offsetof_mcontext_fregs + 13 * sizeof_freg
 141         .cfi_offset     46, offsetof_mcontext_fregs + 14 * sizeof_freg
 142         .cfi_offset     47, offsetof_mcontext_fregs + 15 * sizeof_freg
 143         .cfi_offset     48, offsetof_mcontext_fregs + 16 * sizeof_freg
 144         .cfi_offset     49, offsetof_mcontext_fregs + 17 * sizeof_freg
 145         .cfi_offset     50, offsetof_mcontext_fregs + 18 * sizeof_freg
 146         .cfi_offset     51, offsetof_mcontext_fregs + 19 * sizeof_freg
 147         .cfi_offset     52, offsetof_mcontext_fregs + 20 * sizeof_freg
 148         .cfi_offset     53, offsetof_mcontext_fregs + 21 * sizeof_freg
 149         .cfi_offset     54, offsetof_mcontext_fregs + 22 * sizeof_freg
 150         .cfi_offset     55, offsetof_mcontext_fregs + 23 * sizeof_freg
 151         .cfi_offset     56, offsetof_mcontext_fregs + 24 * sizeof_freg
 152         .cfi_offset     57, offsetof_mcontext_fregs + 25 * sizeof_freg
 153         .cfi_offset     58, offsetof_mcontext_fregs + 26 * sizeof_freg
 154         .cfi_offset     59, offsetof_mcontext_fregs + 27 * sizeof_freg
 155         .cfi_offset     60, offsetof_mcontext_fregs + 28 * sizeof_freg
 156         .cfi_offset     61, offsetof_mcontext_fregs + 29 * sizeof_freg
 157         .cfi_offset     62, offsetof_mcontext_fregs + 30 * sizeof_freg
 158         .cfi_offset     63, offsetof_mcontext_fregs + 31 * sizeof_freg
 159
 160         /*
 161          * Unlike the kernel, unconditionally represent the Altivec/VSX regs.
 162          * The space within the stack frame is always available, and most of
 163          * our supported processors have them enabled.  The only complication
 164          * for PPC64 is the misalignment, so that we have to use indirection.
 165          */
 166 .macro  save_vreg_ofs reg, ofs
 167 #ifdef _ARCH_PPC64
 168         /*
 169          * vreg = *(cfa + offsetof(v_regs)) + ofs
 170          *
 171          * The CFA is input to the expression on the stack, so:
 172          * DW_CFA_expression reg, length (7),
 173          *   DW_OP_plus_uconst (0x23), vreg_ptr, DW_OP_deref (0x06),
 174          *   DW_OP_plus_uconst (0x23), ofs
 175          */
 176         .cfi_escape 0x10, 77 + \reg, 7, 0x23, (offsetof_mcontext_vregs_ptr & 0x7f) + 0x80, offsetof_mcontext_vregs_ptr >> 7, 0x06, 0x23, (\ofs & 0x7f) | 0x80, \ofs >> 7
 177 #else
 178         .cfi_offset 77 + \reg, offsetof_mcontext_vregs + \ofs
 179 #endif
 180 .endm
 181
 182 .macro  save_vreg reg
 183         save_vreg_ofs \reg, (\reg * sizeof_vreg)
 184 .endm
 185
 186         save_vreg   0
 187         save_vreg   1
 188         save_vreg   2
 189         save_vreg   3
 190         save_vreg   4
 191         save_vreg   5
 192         save_vreg   6
 193         save_vreg   7
 194         save_vreg   8
 195         save_vreg   9
 196         save_vreg  10
 197         save_vreg  11
 198         save_vreg  12
 199         save_vreg  13
 200         save_vreg  14
 201         save_vreg  15
 202         save_vreg  16
 203         save_vreg  17
 204         save_vreg  18
 205         save_vreg  19
 206         save_vreg  20
 207         save_vreg  21
 208         save_vreg  22
 209         save_vreg  23
 210         save_vreg  24
 211         save_vreg  25
 212         save_vreg  26
 213         save_vreg  27
 214         save_vreg  28
 215         save_vreg  29
 216         save_vreg  30
 217         save_vreg  31
 218         save_vreg  32
 219         save_vreg_ofs 33, (32 * sizeof_vreg + 12)
 220
 221         nop
 222
 223 __kernel_sigtramp_rt:
 224         raw_syscall __NR_rt_sigreturn
 225 endf    __kernel_sigtramp_rt
 226
 227 #ifndef _ARCH_PPC64
 228         /*
 229          * The non-rt sigreturn has the same layout at a different offset.
 230          * Move the CFA and leave all othe other descriptions the same.
 231          */
 232         .cfi_def_cfa    1, SIGNAL_FRAMESIZE + offsetof_sigframe_mcontext
 233         nop
 234 __kernel_sigtramp32:
 235         raw_syscall __NR_sigreturn
 236 endf    __kernel_sigtramp32
 237 #endif
 238
 239         .cfi_endproc