tools/testing/selftests/rseq/rseq-ppc.h

   1 /* SPDX-License-Identifier: LGPL-2.1 OR MIT */
   2 /*
   3  * rseq-ppc.h
   4  *
   5  * (C) Copyright 2016-2022 - Mathieu Desnoyers <[email protected]>
   6  * (C) Copyright 2016-2018 - Boqun Feng <[email protected]>
   7  */
   8
   9 /*
  10  * RSEQ_SIG is used with the following trap instruction:
  11  *
  12  * powerpc-be:    0f e5 00 0b           twui   r5,11
  13  * powerpc64-le:  0b 00 e5 0f           twui   r5,11
  14  * powerpc64-be:  0f e5 00 0b           twui   r5,11
  15  */
  16
  17 #define RSEQ_SIG        0x0fe5000b
  18
  19 #define rseq_smp_mb()           __asm__ __volatile__ ("sync"    ::: "memory", "cc")
  20 #define rseq_smp_lwsync()       __asm__ __volatile__ ("lwsync"  ::: "memory", "cc")
  21 #define rseq_smp_rmb()          rseq_smp_lwsync()
  22 #define rseq_smp_wmb()          rseq_smp_lwsync()
  23
  24 #define rseq_smp_load_acquire(p)                                        \
  25 __extension__ ({                                                        \
  26         rseq_unqual_scalar_typeof(*(p)) ____p1 = RSEQ_READ_ONCE(*(p));  \
  27         rseq_smp_lwsync();                                              \
  28         ____p1;                                                         \
  29 })
  30
  31 #define rseq_smp_acquire__after_ctrl_dep()      rseq_smp_lwsync()
  32
  33 #define rseq_smp_store_release(p, v)                                    \
  34 do {                                                                    \
  35         rseq_smp_lwsync();                                              \
  36         RSEQ_WRITE_ONCE(*(p), v);                                       \
  37 } while (0)
  38
  39 /*
  40  * The __rseq_cs_ptr_array and __rseq_cs sections can be used by debuggers to
  41  * better handle single-stepping through the restartable critical sections.
  42  */
  43
  44 #ifdef __PPC64__
  45
  46 #define RSEQ_STORE_LONG(arg)    "std%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "    /* To memory ("m" constraint) */
  47 #define RSEQ_STORE_INT(arg)     "stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "    /* To memory ("m" constraint) */
  48 #define RSEQ_LOAD_LONG(arg)     "ld%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "     /* From memory ("m" constraint) */
  49 #define RSEQ_LOAD_INT(arg)      "lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "    /* From memory ("m" constraint) */
  50 #define RSEQ_LOADX_LONG         "ldx "                                                  /* From base register ("b" constraint) */
  51 #define RSEQ_CMP_LONG           "cmpd "
  52 #define RSEQ_CMP_LONG_INT       "cmpdi "
  53
  54 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,                          \
  55                         start_ip, post_commit_offset, abort_ip)                 \
  56                 ".pushsection __rseq_cs, \"aw\"\n\t"                            \
  57                 ".balign 32\n\t"                                                \
  58                 __rseq_str(label) ":\n\t"                                       \
  59                 ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t"      \
  60                 ".quad " __rseq_str(start_ip) ", " __rseq_str(post_commit_offset) ", " __rseq_str(abort_ip) "\n\t" \
  61                 ".popsection\n\t"                                               \
  62                 ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t"                  \
  63                 ".quad " __rseq_str(label) "b\n\t"                              \
  64                 ".popsection\n\t"
  65
  66 #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs)                        \
  67                 RSEQ_INJECT_ASM(1)                                              \
  68                 "lis %%r17, (" __rseq_str(cs_label) ")@highest\n\t"             \
  69                 "ori %%r17, %%r17, (" __rseq_str(cs_label) ")@higher\n\t"       \
  70                 "rldicr %%r17, %%r17, 32, 31\n\t"                               \
  71                 "oris %%r17, %%r17, (" __rseq_str(cs_label) ")@high\n\t"        \
  72                 "ori %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t"            \
  73                 "std %%r17, %[" __rseq_str(rseq_cs) "]\n\t"                     \
  74                 __rseq_str(label) ":\n\t"
  75
  76 /*
  77  * Exit points of a rseq critical section consist of all instructions outside
  78  * of the critical section where a critical section can either branch to or
  79  * reach through the normal course of its execution. The abort IP and the
  80  * post-commit IP are already part of the __rseq_cs section and should not be
  81  * explicitly defined as additional exit points. Knowing all exit points is
  82  * useful to assist debuggers stepping over the critical section.
  83  */
  84 #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip)                   \
  85                 ".pushsection __rseq_exit_point_array, \"aw\"\n\t"      \
  86                 ".quad " __rseq_str(start_ip) ", " __rseq_str(exit_ip) "\n\t" \
  87                 ".popsection\n\t"
  88
  89 #else /* #ifdef __PPC64__ */
  90
  91 #define RSEQ_STORE_LONG(arg)    "stw%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "    /* To memory ("m" constraint) */
  92 #define RSEQ_STORE_INT(arg)     RSEQ_STORE_LONG(arg)                                    /* To memory ("m" constraint) */
  93 #define RSEQ_LOAD_LONG(arg)     "lwz%U[" __rseq_str(arg) "]%X[" __rseq_str(arg) "] "    /* From memory ("m" constraint) */
  94 #define RSEQ_LOAD_INT(arg)      RSEQ_LOAD_LONG(arg)                                     /* From memory ("m" constraint) */
  95 #define RSEQ_LOADX_LONG         "lwzx "                                                 /* From base register ("b" constraint) */
  96 #define RSEQ_CMP_LONG           "cmpw "
  97 #define RSEQ_CMP_LONG_INT       "cmpwi "
  98
  99 #define __RSEQ_ASM_DEFINE_TABLE(label, version, flags,                          \
 100                         start_ip, post_commit_offset, abort_ip)                 \
 101                 ".pushsection __rseq_cs, \"aw\"\n\t"                            \
 102                 ".balign 32\n\t"                                                \
 103                 __rseq_str(label) ":\n\t"                                       \
 104                 ".long " __rseq_str(version) ", " __rseq_str(flags) "\n\t"      \
 105                 /* 32-bit only supported on BE */                               \
 106                 ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(post_commit_offset) ", 0x0, " __rseq_str(abort_ip) "\n\t" \
 107                 ".popsection\n\t"                                       \
 108                 ".pushsection __rseq_cs_ptr_array, \"aw\"\n\t"          \
 109                 ".long 0x0, " __rseq_str(label) "b\n\t"                 \
 110                 ".popsection\n\t"
 111
 112 /*
 113  * Exit points of a rseq critical section consist of all instructions outside
 114  * of the critical section where a critical section can either branch to or
 115  * reach through the normal course of its execution. The abort IP and the
 116  * post-commit IP are already part of the __rseq_cs section and should not be
 117  * explicitly defined as additional exit points. Knowing all exit points is
 118  * useful to assist debuggers stepping over the critical section.
 119  */
 120 #define RSEQ_ASM_DEFINE_EXIT_POINT(start_ip, exit_ip)                           \
 121                 ".pushsection __rseq_exit_point_array, \"aw\"\n\t"              \
 122                 /* 32-bit only supported on BE */                               \
 123                 ".long 0x0, " __rseq_str(start_ip) ", 0x0, " __rseq_str(exit_ip) "\n\t" \
 124                 ".popsection\n\t"
 125
 126 #define RSEQ_ASM_STORE_RSEQ_CS(label, cs_label, rseq_cs)                        \
 127                 RSEQ_INJECT_ASM(1)                                              \
 128                 "lis %%r17, (" __rseq_str(cs_label) ")@ha\n\t"                  \
 129                 "addi %%r17, %%r17, (" __rseq_str(cs_label) ")@l\n\t"           \
 130                 RSEQ_STORE_INT(rseq_cs) "%%r17, %[" __rseq_str(rseq_cs) "]\n\t" \
 131                 __rseq_str(label) ":\n\t"
 132
 133 #endif /* #ifdef __PPC64__ */
 134
 135 #define RSEQ_ASM_DEFINE_TABLE(label, start_ip, post_commit_ip, abort_ip)        \
 136                 __RSEQ_ASM_DEFINE_TABLE(label, 0x0, 0x0, start_ip,              \
 137                                         (post_commit_ip - start_ip), abort_ip)
 138
 139 #define RSEQ_ASM_CMP_CPU_ID(cpu_id, current_cpu_id, label)                      \
 140                 RSEQ_INJECT_ASM(2)                                              \
 141                 RSEQ_LOAD_INT(current_cpu_id) "%%r17, %[" __rseq_str(current_cpu_id) "]\n\t" \
 142                 "cmpw cr7, %[" __rseq_str(cpu_id) "], %%r17\n\t"                \
 143                 "bne- cr7, " __rseq_str(label) "\n\t"
 144
 145 #define RSEQ_ASM_DEFINE_ABORT(label, abort_label)                               \
 146                 ".pushsection __rseq_failure, \"ax\"\n\t"                       \
 147                 ".long " __rseq_str(RSEQ_SIG) "\n\t"                            \
 148                 __rseq_str(label) ":\n\t"                                       \
 149                 "b %l[" __rseq_str(abort_label) "]\n\t"                         \
 150                 ".popsection\n\t"
 151
 152 /*
 153  * RSEQ_ASM_OPs: asm operations for rseq
 154  *      RSEQ_ASM_OP_R_*: has hard-code registers in it
 155  *      RSEQ_ASM_OP_* (else): doesn't have hard-code registers(unless cr7)
 156  */
 157 #define RSEQ_ASM_OP_CMPEQ(var, expect, label)                                   \
 158                 RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"         \
 159                 RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expect) "]\n\t"               \
 160                 "bne- cr7, " __rseq_str(label) "\n\t"
 161
 162 #define RSEQ_ASM_OP_CMPNE(var, expectnot, label)                                \
 163                 RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"         \
 164                 RSEQ_CMP_LONG "cr7, %%r17, %[" __rseq_str(expectnot) "]\n\t"            \
 165                 "beq- cr7, " __rseq_str(label) "\n\t"
 166
 167 #define RSEQ_ASM_OP_STORE(value, var)                                           \
 168                 RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t"
 169
 170 /* Load @var to r17 */
 171 #define RSEQ_ASM_OP_R_LOAD(var)                                                 \
 172                 RSEQ_LOAD_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 173
 174 /* Store r17 to @var */
 175 #define RSEQ_ASM_OP_R_STORE(var)                                                \
 176                 RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"
 177
 178 /* Add @count to r17 */
 179 #define RSEQ_ASM_OP_R_ADD(count)                                                \
 180                 "add %%r17, %[" __rseq_str(count) "], %%r17\n\t"
 181
 182 /* Load (r17 + voffp) to r17 */
 183 #define RSEQ_ASM_OP_R_LOADX(voffp)                                              \
 184                 RSEQ_LOADX_LONG "%%r17, %[" __rseq_str(voffp) "], %%r17\n\t"
 185
 186 /* TODO: implement a faster memcpy. */
 187 #define RSEQ_ASM_OP_R_MEMCPY() \
 188                 RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 189                 "beq 333f\n\t" \
 190                 "addi %%r20, %%r20, -1\n\t" \
 191                 "addi %%r21, %%r21, -1\n\t" \
 192                 "222:\n\t" \
 193                 "lbzu %%r18, 1(%%r20)\n\t" \
 194                 "stbu %%r18, 1(%%r21)\n\t" \
 195                 "addi %%r19, %%r19, -1\n\t" \
 196                 RSEQ_CMP_LONG_INT "%%r19, 0\n\t" \
 197                 "bne 222b\n\t" \
 198                 "333:\n\t" \
 199
 200 #define RSEQ_ASM_OP_R_FINAL_STORE(var, post_commit_label)                       \
 201                 RSEQ_STORE_LONG(var) "%%r17, %[" __rseq_str(var) "]\n\t"                        \
 202                 __rseq_str(post_commit_label) ":\n\t"
 203
 204 #define RSEQ_ASM_OP_FINAL_STORE(value, var, post_commit_label)                  \
 205                 RSEQ_STORE_LONG(var) "%[" __rseq_str(value) "], %[" __rseq_str(var) "]\n\t" \
 206                 __rseq_str(post_commit_label) ":\n\t"
 207
 208 /* Per-cpu-id indexing. */
 209
 210 #define RSEQ_TEMPLATE_CPU_ID
 211 #define RSEQ_TEMPLATE_MO_RELAXED
 212 #include "rseq-ppc-bits.h"
 213 #undef RSEQ_TEMPLATE_MO_RELAXED
 214
 215 #define RSEQ_TEMPLATE_MO_RELEASE
 216 #include "rseq-ppc-bits.h"
 217 #undef RSEQ_TEMPLATE_MO_RELEASE
 218 #undef RSEQ_TEMPLATE_CPU_ID
 219
 220 /* Per-mm-cid indexing. */
 221
 222 #define RSEQ_TEMPLATE_MM_CID
 223 #define RSEQ_TEMPLATE_MO_RELAXED
 224 #include "rseq-ppc-bits.h"
 225 #undef RSEQ_TEMPLATE_MO_RELAXED
 226
 227 #define RSEQ_TEMPLATE_MO_RELEASE
 228 #include "rseq-ppc-bits.h"
 229 #undef RSEQ_TEMPLATE_MO_RELEASE
 230 #undef RSEQ_TEMPLATE_MM_CID
 231
 232 /* APIs which are not based on cpu ids. */
 233
 234 #define RSEQ_TEMPLATE_CPU_ID_NONE
 235 #define RSEQ_TEMPLATE_MO_RELAXED
 236 #include "rseq-ppc-bits.h"
 237 #undef RSEQ_TEMPLATE_MO_RELAXED
 238 #undef RSEQ_TEMPLATE_CPU_ID_NONE