arch/loongarch/include/asm/percpu.h

   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
  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
  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
  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
 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 */