1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5 #ifndef __ASM_PERCPU_H
6 #define __ASM_PERCPU_H
7
8 #include <asm/cmpxchg.h>
9 #include <asm/loongarch.h>
10
11 /*
12 * The "address" (in fact, offset from $r21) of a per-CPU variable is close to
13 * the loading address of main kernel image, but far from where the modules are
14 * loaded. Tell the compiler this fact when using explicit relocs.
15 */
16 #if defined(MODULE) && defined(CONFIG_AS_HAS_EXPLICIT_RELOCS)
17 #define PER_CPU_ATTRIBUTES __attribute__((model("extreme")))
18 #endif
19
20 /* Use r21 for fast access */
21 register unsigned long __my_cpu_offset __asm__("$r21");
22
set_my_cpu_offset(unsigned long off)23 static inline void set_my_cpu_offset(unsigned long off)
24 {
25 __my_cpu_offset = off;
26 csr_write64(off, PERCPU_BASE_KS);
27 }
28 #define __my_cpu_offset __my_cpu_offset
29
30 #define PERCPU_OP(op, asm_op, c_op) \
31 static inline unsigned long __percpu_##op(void *ptr, \
32 unsigned long val, int size) \
33 { \
34 unsigned long ret; \
35 \
36 switch (size) { \
37 case 4: \
38 __asm__ __volatile__( \
39 "am"#asm_op".w" " %[ret], %[val], %[ptr] \n" \
40 : [ret] "=&r" (ret), [ptr] "+ZB"(*(u32 *)ptr) \
41 : [val] "r" (val)); \
42 break; \
43 case 8: \
44 __asm__ __volatile__( \
45 "am"#asm_op".d" " %[ret], %[val], %[ptr] \n" \
46 : [ret] "=&r" (ret), [ptr] "+ZB"(*(u64 *)ptr) \
47 : [val] "r" (val)); \
48 break; \
49 default: \
50 ret = 0; \
51 BUILD_BUG(); \
52 } \
53 \
54 return ret c_op val; \
55 }
56
57 PERCPU_OP(add, add, +)
58 PERCPU_OP(and, and, &)
59 PERCPU_OP(or, or, |)
60 #undef PERCPU_OP
61
__percpu_read(void * ptr,int size)62 static inline unsigned long __percpu_read(void *ptr, int size)
63 {
64 unsigned long ret;
65
66 switch (size) {
67 case 1:
68 __asm__ __volatile__ ("ldx.b %[ret], $r21, %[ptr] \n"
69 : [ret] "=&r"(ret)
70 : [ptr] "r"(ptr)
71 : "memory");
72 break;
73 case 2:
74 __asm__ __volatile__ ("ldx.h %[ret], $r21, %[ptr] \n"
75 : [ret] "=&r"(ret)
76 : [ptr] "r"(ptr)
77 : "memory");
78 break;
79 case 4:
80 __asm__ __volatile__ ("ldx.w %[ret], $r21, %[ptr] \n"
81 : [ret] "=&r"(ret)
82 : [ptr] "r"(ptr)
83 : "memory");
84 break;
85 case 8:
86 __asm__ __volatile__ ("ldx.d %[ret], $r21, %[ptr] \n"
87 : [ret] "=&r"(ret)
88 : [ptr] "r"(ptr)
89 : "memory");
90 break;
91 default:
92 ret = 0;
93 BUILD_BUG();
94 }
95
96 return ret;
97 }
98
__percpu_write(void * ptr,unsigned long val,int size)99 static inline void __percpu_write(void *ptr, unsigned long val, int size)
100 {
101 switch (size) {
102 case 1:
103 __asm__ __volatile__("stx.b %[val], $r21, %[ptr] \n"
104 :
105 : [val] "r" (val), [ptr] "r" (ptr)
106 : "memory");
107 break;
108 case 2:
109 __asm__ __volatile__("stx.h %[val], $r21, %[ptr] \n"
110 :
111 : [val] "r" (val), [ptr] "r" (ptr)
112 : "memory");
113 break;
114 case 4:
115 __asm__ __volatile__("stx.w %[val], $r21, %[ptr] \n"
116 :
117 : [val] "r" (val), [ptr] "r" (ptr)
118 : "memory");
119 break;
120 case 8:
121 __asm__ __volatile__("stx.d %[val], $r21, %[ptr] \n"
122 :
123 : [val] "r" (val), [ptr] "r" (ptr)
124 : "memory");
125 break;
126 default:
127 BUILD_BUG();
128 }
129 }
130
__percpu_xchg(void * ptr,unsigned long val,int size)131 static inline unsigned long __percpu_xchg(void *ptr, unsigned long val,
132 int size)
133 {
134 switch (size) {
135 case 1:
136 case 2:
137 return __xchg_small((volatile void *)ptr, val, size);
138
139 case 4:
140 return __xchg_asm("amswap.w", (volatile u32 *)ptr, (u32)val);
141
142 case 8:
143 return __xchg_asm("amswap.d", (volatile u64 *)ptr, (u64)val);
144
145 default:
146 BUILD_BUG();
147 }
148
149 return 0;
150 }
151
152 /* this_cpu_cmpxchg */
153 #define _protect_cmpxchg_local(pcp, o, n) \
154 ({ \
155 typeof(*raw_cpu_ptr(&(pcp))) __ret; \
156 preempt_disable_notrace(); \
157 __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \
158 preempt_enable_notrace(); \
159 __ret; \
160 })
161
162 #define _percpu_read(pcp) \
163 ({ \
164 typeof(pcp) __retval; \
165 __retval = (typeof(pcp))__percpu_read(&(pcp), sizeof(pcp)); \
166 __retval; \
167 })
168
169 #define _percpu_write(pcp, val) \
170 do { \
171 __percpu_write(&(pcp), (unsigned long)(val), sizeof(pcp)); \
172 } while (0) \
173
174 #define _pcp_protect(operation, pcp, val) \
175 ({ \
176 typeof(pcp) __retval; \
177 preempt_disable_notrace(); \
178 __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \
179 (val), sizeof(pcp)); \
180 preempt_enable_notrace(); \
181 __retval; \
182 })
183
184 #define _percpu_add(pcp, val) \
185 _pcp_protect(__percpu_add, pcp, val)
186
187 #define _percpu_add_return(pcp, val) _percpu_add(pcp, val)
188
189 #define _percpu_and(pcp, val) \
190 _pcp_protect(__percpu_and, pcp, val)
191
192 #define _percpu_or(pcp, val) \
193 _pcp_protect(__percpu_or, pcp, val)
194
195 #define _percpu_xchg(pcp, val) ((typeof(pcp)) \
196 _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val)))
197
198 #define this_cpu_add_4(pcp, val) _percpu_add(pcp, val)
199 #define this_cpu_add_8(pcp, val) _percpu_add(pcp, val)
200
201 #define this_cpu_add_return_4(pcp, val) _percpu_add_return(pcp, val)
202 #define this_cpu_add_return_8(pcp, val) _percpu_add_return(pcp, val)
203
204 #define this_cpu_and_4(pcp, val) _percpu_and(pcp, val)
205 #define this_cpu_and_8(pcp, val) _percpu_and(pcp, val)
206
207 #define this_cpu_or_4(pcp, val) _percpu_or(pcp, val)
208 #define this_cpu_or_8(pcp, val) _percpu_or(pcp, val)
209
210 #define this_cpu_read_1(pcp) _percpu_read(pcp)
211 #define this_cpu_read_2(pcp) _percpu_read(pcp)
212 #define this_cpu_read_4(pcp) _percpu_read(pcp)
213 #define this_cpu_read_8(pcp) _percpu_read(pcp)
214
215 #define this_cpu_write_1(pcp, val) _percpu_write(pcp, val)
216 #define this_cpu_write_2(pcp, val) _percpu_write(pcp, val)
217 #define this_cpu_write_4(pcp, val) _percpu_write(pcp, val)
218 #define this_cpu_write_8(pcp, val) _percpu_write(pcp, val)
219
220 #define this_cpu_xchg_1(pcp, val) _percpu_xchg(pcp, val)
221 #define this_cpu_xchg_2(pcp, val) _percpu_xchg(pcp, val)
222 #define this_cpu_xchg_4(pcp, val) _percpu_xchg(pcp, val)
223 #define this_cpu_xchg_8(pcp, val) _percpu_xchg(pcp, val)
224
225 #define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
226 #define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
227 #define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
228 #define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
229
230 #include <asm-generic/percpu.h>
231
232 #endif /* __ASM_PERCPU_H */
233