2 * Copyright (C) 2013 ARM Ltd.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
13 * You should have received a copy of the GNU General Public License
14 * along with this program. If not, see <http://www.gnu.org/licenses/>.
16 #ifndef __ASM_PERCPU_H
17 #define __ASM_PERCPU_H
19 #include <linux/preempt.h>
21 #include <asm/alternative.h>
22 #include <asm/cmpxchg.h>
23 #include <asm/stack_pointer.h>
25 static inline void set_my_cpu_offset(unsigned long off)
27 asm volatile(ALTERNATIVE("msr tpidr_el1, %0",
29 ARM64_HAS_VIRT_HOST_EXTN)
30 :: "r" (off) : "memory");
33 static inline unsigned long __my_cpu_offset(void)
38 * We want to allow caching the value, so avoid using volatile and
39 * instead use a fake stack read to hazard against barrier().
41 asm(ALTERNATIVE("mrs %0, tpidr_el1",
43 ARM64_HAS_VIRT_HOST_EXTN)
45 "Q" (*(const unsigned long *)current_stack_pointer));
49 #define __my_cpu_offset __my_cpu_offset()
51 #define PERCPU_OP(op, asm_op) \
52 static inline unsigned long __percpu_##op(void *ptr, \
53 unsigned long val, int size) \
55 unsigned long loop, ret; \
59 asm ("//__per_cpu_" #op "_1\n" \
60 "1: ldxrb %w[ret], %[ptr]\n" \
61 #asm_op " %w[ret], %w[ret], %w[val]\n" \
62 " stxrb %w[loop], %w[ret], %[ptr]\n" \
63 " cbnz %w[loop], 1b" \
64 : [loop] "=&r" (loop), [ret] "=&r" (ret), \
65 [ptr] "+Q"(*(u8 *)ptr) \
66 : [val] "Ir" (val)); \
69 asm ("//__per_cpu_" #op "_2\n" \
70 "1: ldxrh %w[ret], %[ptr]\n" \
71 #asm_op " %w[ret], %w[ret], %w[val]\n" \
72 " stxrh %w[loop], %w[ret], %[ptr]\n" \
73 " cbnz %w[loop], 1b" \
74 : [loop] "=&r" (loop), [ret] "=&r" (ret), \
75 [ptr] "+Q"(*(u16 *)ptr) \
76 : [val] "Ir" (val)); \
79 asm ("//__per_cpu_" #op "_4\n" \
80 "1: ldxr %w[ret], %[ptr]\n" \
81 #asm_op " %w[ret], %w[ret], %w[val]\n" \
82 " stxr %w[loop], %w[ret], %[ptr]\n" \
83 " cbnz %w[loop], 1b" \
84 : [loop] "=&r" (loop), [ret] "=&r" (ret), \
85 [ptr] "+Q"(*(u32 *)ptr) \
86 : [val] "Ir" (val)); \
89 asm ("//__per_cpu_" #op "_8\n" \
90 "1: ldxr %[ret], %[ptr]\n" \
91 #asm_op " %[ret], %[ret], %[val]\n" \
92 " stxr %w[loop], %[ret], %[ptr]\n" \
93 " cbnz %w[loop], 1b" \
94 : [loop] "=&r" (loop), [ret] "=&r" (ret), \
95 [ptr] "+Q"(*(u64 *)ptr) \
96 : [val] "Ir" (val)); \
110 static inline unsigned long __percpu_read(void *ptr, int size)
116 ret = READ_ONCE(*(u8 *)ptr);
119 ret = READ_ONCE(*(u16 *)ptr);
122 ret = READ_ONCE(*(u32 *)ptr);
125 ret = READ_ONCE(*(u64 *)ptr);
134 static inline void __percpu_write(void *ptr, unsigned long val, int size)
138 WRITE_ONCE(*(u8 *)ptr, (u8)val);
141 WRITE_ONCE(*(u16 *)ptr, (u16)val);
144 WRITE_ONCE(*(u32 *)ptr, (u32)val);
147 WRITE_ONCE(*(u64 *)ptr, (u64)val);
154 static inline unsigned long __percpu_xchg(void *ptr, unsigned long val,
157 unsigned long ret, loop;
161 asm ("//__percpu_xchg_1\n"
162 "1: ldxrb %w[ret], %[ptr]\n"
163 " stxrb %w[loop], %w[val], %[ptr]\n"
165 : [loop] "=&r"(loop), [ret] "=&r"(ret),
166 [ptr] "+Q"(*(u8 *)ptr)
170 asm ("//__percpu_xchg_2\n"
171 "1: ldxrh %w[ret], %[ptr]\n"
172 " stxrh %w[loop], %w[val], %[ptr]\n"
174 : [loop] "=&r"(loop), [ret] "=&r"(ret),
175 [ptr] "+Q"(*(u16 *)ptr)
179 asm ("//__percpu_xchg_4\n"
180 "1: ldxr %w[ret], %[ptr]\n"
181 " stxr %w[loop], %w[val], %[ptr]\n"
183 : [loop] "=&r"(loop), [ret] "=&r"(ret),
184 [ptr] "+Q"(*(u32 *)ptr)
188 asm ("//__percpu_xchg_8\n"
189 "1: ldxr %[ret], %[ptr]\n"
190 " stxr %w[loop], %[val], %[ptr]\n"
192 : [loop] "=&r"(loop), [ret] "=&r"(ret),
193 [ptr] "+Q"(*(u64 *)ptr)
203 /* this_cpu_cmpxchg */
204 #define _protect_cmpxchg_local(pcp, o, n) \
206 typeof(*raw_cpu_ptr(&(pcp))) __ret; \
208 __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \
213 #define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
214 #define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
215 #define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
216 #define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
218 #define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \
222 __ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \
223 raw_cpu_ptr(&(ptr2)), \
229 #define _percpu_read(pcp) \
231 typeof(pcp) __retval; \
232 preempt_disable_notrace(); \
233 __retval = (typeof(pcp))__percpu_read(raw_cpu_ptr(&(pcp)), \
235 preempt_enable_notrace(); \
239 #define _percpu_write(pcp, val) \
241 preempt_disable_notrace(); \
242 __percpu_write(raw_cpu_ptr(&(pcp)), (unsigned long)(val), \
244 preempt_enable_notrace(); \
247 #define _pcp_protect(operation, pcp, val) \
249 typeof(pcp) __retval; \
251 __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \
252 (val), sizeof(pcp)); \
257 #define _percpu_add(pcp, val) \
258 _pcp_protect(__percpu_add, pcp, val)
260 #define _percpu_add_return(pcp, val) _percpu_add(pcp, val)
262 #define _percpu_and(pcp, val) \
263 _pcp_protect(__percpu_and, pcp, val)
265 #define _percpu_or(pcp, val) \
266 _pcp_protect(__percpu_or, pcp, val)
268 #define _percpu_xchg(pcp, val) (typeof(pcp)) \
269 _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val))
271 #define this_cpu_add_1(pcp, val) _percpu_add(pcp, val)
272 #define this_cpu_add_2(pcp, val) _percpu_add(pcp, val)
273 #define this_cpu_add_4(pcp, val) _percpu_add(pcp, val)
274 #define this_cpu_add_8(pcp, val) _percpu_add(pcp, val)
276 #define this_cpu_add_return_1(pcp, val) _percpu_add_return(pcp, val)
277 #define this_cpu_add_return_2(pcp, val) _percpu_add_return(pcp, val)
278 #define this_cpu_add_return_4(pcp, val) _percpu_add_return(pcp, val)
279 #define this_cpu_add_return_8(pcp, val) _percpu_add_return(pcp, val)
281 #define this_cpu_and_1(pcp, val) _percpu_and(pcp, val)
282 #define this_cpu_and_2(pcp, val) _percpu_and(pcp, val)
283 #define this_cpu_and_4(pcp, val) _percpu_and(pcp, val)
284 #define this_cpu_and_8(pcp, val) _percpu_and(pcp, val)
286 #define this_cpu_or_1(pcp, val) _percpu_or(pcp, val)
287 #define this_cpu_or_2(pcp, val) _percpu_or(pcp, val)
288 #define this_cpu_or_4(pcp, val) _percpu_or(pcp, val)
289 #define this_cpu_or_8(pcp, val) _percpu_or(pcp, val)
291 #define this_cpu_read_1(pcp) _percpu_read(pcp)
292 #define this_cpu_read_2(pcp) _percpu_read(pcp)
293 #define this_cpu_read_4(pcp) _percpu_read(pcp)
294 #define this_cpu_read_8(pcp) _percpu_read(pcp)
296 #define this_cpu_write_1(pcp, val) _percpu_write(pcp, val)
297 #define this_cpu_write_2(pcp, val) _percpu_write(pcp, val)
298 #define this_cpu_write_4(pcp, val) _percpu_write(pcp, val)
299 #define this_cpu_write_8(pcp, val) _percpu_write(pcp, val)
301 #define this_cpu_xchg_1(pcp, val) _percpu_xchg(pcp, val)
302 #define this_cpu_xchg_2(pcp, val) _percpu_xchg(pcp, val)
303 #define this_cpu_xchg_4(pcp, val) _percpu_xchg(pcp, val)
304 #define this_cpu_xchg_8(pcp, val) _percpu_xchg(pcp, val)
306 #include <asm-generic/percpu.h>
308 #endif /* __ASM_PERCPU_H */