xref: /linux/scripts/atomic/gen-atomic-fallback.sh (revision 6e7fd890f1d6ac83805409e9c346240de2705584) 
1#!/bin/sh
2# SPDX-License-Identifier: GPL-2.0
3
4ATOMICDIR=$(dirname $0)
5
6. ${ATOMICDIR}/atomic-tbl.sh
7
8#gen_template_fallback(template, meta, pfx, name, sfx, order, atomic, int, args...)
9gen_template_fallback()
10{
11	local template="$1"; shift
12	local meta="$1"; shift
13	local pfx="$1"; shift
14	local name="$1"; shift
15	local sfx="$1"; shift
16	local order="$1"; shift
17	local atomic="$1"; shift
18	local int="$1"; shift
19
20	local ret="$(gen_ret_type "${meta}" "${int}")"
21	local retstmt="$(gen_ret_stmt "${meta}")"
22	local params="$(gen_params "${int}" "${atomic}" "$@")"
23	local args="$(gen_args "$@")"
24
25	. ${template}
26}
27
28#gen_order_fallback(meta, pfx, name, sfx, order, atomic, int, args...)
29gen_order_fallback()
30{
31	local meta="$1"; shift
32	local pfx="$1"; shift
33	local name="$1"; shift
34	local sfx="$1"; shift
35	local order="$1"; shift
36
37	local tmpl_order=${order#_}
38	local tmpl="${ATOMICDIR}/fallbacks/${tmpl_order:-fence}"
39	gen_template_fallback "${tmpl}" "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "$@"
40}
41
42#gen_proto_fallback(meta, pfx, name, sfx, order, atomic, int, args...)
43gen_proto_fallback()
44{
45	local meta="$1"; shift
46	local pfx="$1"; shift
47	local name="$1"; shift
48	local sfx="$1"; shift
49	local order="$1"; shift
50
51	local tmpl="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
52	gen_template_fallback "${tmpl}" "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "$@"
53}
54
55#gen_proto_order_variant(meta, pfx, name, sfx, order, atomic, int, args...)
56gen_proto_order_variant()
57{
58	local meta="$1"; shift
59	local pfx="$1"; shift
60	local name="$1"; shift
61	local sfx="$1"; shift
62	local order="$1"; shift
63	local atomic="$1"; shift
64	local int="$1"; shift
65
66	local atomicname="${atomic}_${pfx}${name}${sfx}${order}"
67	local basename="${atomic}_${pfx}${name}${sfx}"
68
69	local template="$(find_fallback_template "${pfx}" "${name}" "${sfx}" "${order}")"
70
71	local ret="$(gen_ret_type "${meta}" "${int}")"
72	local retstmt="$(gen_ret_stmt "${meta}")"
73	local params="$(gen_params "${int}" "${atomic}" "$@")"
74	local args="$(gen_args "$@")"
75
76	gen_kerneldoc "raw_" "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "${atomic}" "${int}" "$@"
77
78	printf "static __always_inline ${ret}\n"
79	printf "raw_${atomicname}(${params})\n"
80	printf "{\n"
81
82	# Where there is no possible fallback, this order variant is mandatory
83	# and must be provided by arch code. Add a comment to the header to
84	# make this obvious.
85	#
86	# Ideally we'd error on a missing definition, but arch code might
87	# define this order variant as a C function without a preprocessor
88	# symbol.
89	if [ -z ${template} ] && [ -z "${order}" ] && ! meta_has_relaxed "${meta}"; then
90		printf "\t${retstmt}arch_${atomicname}(${args});\n"
91		printf "}\n\n"
92		return
93	fi
94
95	printf "#if defined(arch_${atomicname})\n"
96	printf "\t${retstmt}arch_${atomicname}(${args});\n"
97
98	# Allow FULL/ACQUIRE/RELEASE ops to be defined in terms of RELAXED ops
99	if [ "${order}" != "_relaxed" ] && meta_has_relaxed "${meta}"; then
100		printf "#elif defined(arch_${basename}_relaxed)\n"
101		gen_order_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "${atomic}" "${int}" "$@"
102	fi
103
104	# Allow ACQUIRE/RELEASE/RELAXED ops to be defined in terms of FULL ops
105	if [ ! -z "${order}" ] && ! meta_is_implicitly_relaxed "${meta}"; then
106		printf "#elif defined(arch_${basename})\n"
107		printf "\t${retstmt}arch_${basename}(${args});\n"
108	fi
109
110	printf "#else\n"
111	if [ ! -z "${template}" ]; then
112		gen_proto_fallback "${meta}" "${pfx}" "${name}" "${sfx}" "${order}" "${atomic}" "${int}" "$@"
113	else
114		printf "#error \"Unable to define raw_${atomicname}\"\n"
115	fi
116
117	printf "#endif\n"
118	printf "}\n\n"
119}
120
121
122#gen_proto_order_variants(meta, pfx, name, sfx, atomic, int, args...)
123gen_proto_order_variants()
124{
125	local meta="$1"; shift
126	local pfx="$1"; shift
127	local name="$1"; shift
128	local sfx="$1"; shift
129	local atomic="$1"
130
131	gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "" "$@"
132
133	if meta_has_acquire "${meta}"; then
134		gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_acquire" "$@"
135	fi
136
137	if meta_has_release "${meta}"; then
138		gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_release" "$@"
139	fi
140
141	if meta_has_relaxed "${meta}"; then
142		gen_proto_order_variant "${meta}" "${pfx}" "${name}" "${sfx}" "_relaxed" "$@"
143	fi
144}
145
146#gen_basic_fallbacks(basename)
147gen_basic_fallbacks()
148{
149	local basename="$1"; shift
150cat << EOF
151#define raw_${basename}_acquire arch_${basename}
152#define raw_${basename}_release arch_${basename}
153#define raw_${basename}_relaxed arch_${basename}
154EOF
155}
156
157gen_order_fallbacks()
158{
159	local xchg="$1"; shift
160
161cat <<EOF
162
163#define raw_${xchg}_relaxed arch_${xchg}_relaxed
164
165#ifdef arch_${xchg}_acquire
166#define raw_${xchg}_acquire arch_${xchg}_acquire
167#else
168#define raw_${xchg}_acquire(...) \\
169	__atomic_op_acquire(arch_${xchg}, __VA_ARGS__)
170#endif
171
172#ifdef arch_${xchg}_release
173#define raw_${xchg}_release arch_${xchg}_release
174#else
175#define raw_${xchg}_release(...) \\
176	__atomic_op_release(arch_${xchg}, __VA_ARGS__)
177#endif
178
179#ifdef arch_${xchg}
180#define raw_${xchg} arch_${xchg}
181#else
182#define raw_${xchg}(...) \\
183	__atomic_op_fence(arch_${xchg}, __VA_ARGS__)
184#endif
185
186EOF
187}
188
189gen_xchg_order_fallback()
190{
191	local xchg="$1"; shift
192	local order="$1"; shift
193	local forder="${order:-_fence}"
194
195	printf "#if defined(arch_${xchg}${order})\n"
196	printf "#define raw_${xchg}${order} arch_${xchg}${order}\n"
197
198	if [ "${order}" != "_relaxed" ]; then
199		printf "#elif defined(arch_${xchg}_relaxed)\n"
200		printf "#define raw_${xchg}${order}(...) \\\\\n"
201		printf "	__atomic_op${forder}(arch_${xchg}, __VA_ARGS__)\n"
202	fi
203
204	if [ ! -z "${order}" ]; then
205		printf "#elif defined(arch_${xchg})\n"
206		printf "#define raw_${xchg}${order} arch_${xchg}\n"
207	fi
208
209	printf "#else\n"
210	printf "extern void raw_${xchg}${order}_not_implemented(void);\n"
211	printf "#define raw_${xchg}${order}(...) raw_${xchg}${order}_not_implemented()\n"
212	printf "#endif\n\n"
213}
214
215gen_xchg_fallbacks()
216{
217	local xchg="$1"; shift
218
219	for order in "" "_acquire" "_release" "_relaxed"; do
220		gen_xchg_order_fallback "${xchg}" "${order}"
221	done
222}
223
224gen_try_cmpxchg_fallback()
225{
226	local prefix="$1"; shift
227	local cmpxchg="$1"; shift;
228	local suffix="$1"; shift;
229
230cat <<EOF
231#define raw_${prefix}try_${cmpxchg}${suffix}(_ptr, _oldp, _new) \\
232({ \\
233	typeof(*(_ptr)) *___op = (_oldp), ___o = *___op, ___r; \\
234	___r = raw_${prefix}${cmpxchg}${suffix}((_ptr), ___o, (_new)); \\
235	if (unlikely(___r != ___o)) \\
236		*___op = ___r; \\
237	likely(___r == ___o); \\
238})
239EOF
240}
241
242gen_try_cmpxchg_order_fallback()
243{
244	local cmpxchg="$1"; shift
245	local order="$1"; shift
246	local forder="${order:-_fence}"
247
248	printf "#if defined(arch_try_${cmpxchg}${order})\n"
249	printf "#define raw_try_${cmpxchg}${order} arch_try_${cmpxchg}${order}\n"
250
251	if [ "${order}" != "_relaxed" ]; then
252		printf "#elif defined(arch_try_${cmpxchg}_relaxed)\n"
253		printf "#define raw_try_${cmpxchg}${order}(...) \\\\\n"
254		printf "	__atomic_op${forder}(arch_try_${cmpxchg}, __VA_ARGS__)\n"
255	fi
256
257	if [ ! -z "${order}" ]; then
258		printf "#elif defined(arch_try_${cmpxchg})\n"
259		printf "#define raw_try_${cmpxchg}${order} arch_try_${cmpxchg}\n"
260	fi
261
262	printf "#else\n"
263	gen_try_cmpxchg_fallback "" "${cmpxchg}" "${order}"
264	printf "#endif\n\n"
265}
266
267gen_try_cmpxchg_order_fallbacks()
268{
269	local cmpxchg="$1"; shift;
270
271	for order in "" "_acquire" "_release" "_relaxed"; do
272		gen_try_cmpxchg_order_fallback "${cmpxchg}" "${order}"
273	done
274}
275
276gen_def_and_try_cmpxchg_fallback()
277{
278	local prefix="$1"; shift
279	local cmpxchg="$1"; shift
280	local suffix="$1"; shift
281
282	printf "#define raw_${prefix}${cmpxchg}${suffix} arch_${prefix}${cmpxchg}${suffix}\n\n"
283	printf "#ifdef arch_${prefix}try_${cmpxchg}${suffix}\n"
284	printf "#define raw_${prefix}try_${cmpxchg}${suffix} arch_${prefix}try_${cmpxchg}${suffix}\n"
285	printf "#else\n"
286	gen_try_cmpxchg_fallback "${prefix}" "${cmpxchg}" "${suffix}"
287	printf "#endif\n\n"
288}
289
290cat << EOF
291// SPDX-License-Identifier: GPL-2.0
292
293// Generated by $0
294// DO NOT MODIFY THIS FILE DIRECTLY
295
296#ifndef _LINUX_ATOMIC_FALLBACK_H
297#define _LINUX_ATOMIC_FALLBACK_H
298
299#include <linux/compiler.h>
300
301EOF
302
303for xchg in "xchg" "cmpxchg" "cmpxchg64" "cmpxchg128"; do
304	gen_xchg_fallbacks "${xchg}"
305done
306
307for cmpxchg in "cmpxchg" "cmpxchg64" "cmpxchg128"; do
308	gen_try_cmpxchg_order_fallbacks "${cmpxchg}"
309done
310
311for cmpxchg in "cmpxchg" "cmpxchg64" "cmpxchg128"; do
312	gen_def_and_try_cmpxchg_fallback "" "${cmpxchg}" "_local"
313done
314
315for cmpxchg in "cmpxchg"; do
316	gen_def_and_try_cmpxchg_fallback "sync_" "${cmpxchg}" ""
317done
318
319grep '^[a-z]' "$1" | while read name meta args; do
320	gen_proto "${meta}" "${name}" "atomic" "int" ${args}
321done
322
323cat <<EOF
324#ifdef CONFIG_GENERIC_ATOMIC64
325#include <asm-generic/atomic64.h>
326#endif
327
328EOF
329
330grep '^[a-z]' "$1" | while read name meta args; do
331	gen_proto "${meta}" "${name}" "atomic64" "s64" ${args}
332done
333
334cat <<EOF
335#endif /* _LINUX_ATOMIC_FALLBACK_H */
336EOF
337