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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) \
34do { \
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