1 #ifndef _ASM_X86_PERCPU_H 2 #define _ASM_X86_PERCPU_H 3 4 #ifdef CONFIG_X86_64 5 #define __percpu_seg gs 6 #define __percpu_mov_op movq 7 #else 8 #define __percpu_seg fs 9 #define __percpu_mov_op movl 10 #endif 11 12 #ifdef __ASSEMBLY__ 13 14 /* 15 * PER_CPU finds an address of a per-cpu variable. 16 * 17 * Args: 18 * var - variable name 19 * reg - 32bit register 20 * 21 * The resulting address is stored in the "reg" argument. 22 * 23 * Example: 24 * PER_CPU(cpu_gdt_descr, %ebx) 25 */ 26 #ifdef CONFIG_SMP 27 #define PER_CPU(var, reg) \ 28 __percpu_mov_op %__percpu_seg:per_cpu__this_cpu_off, reg; \ 29 lea per_cpu__##var(reg), reg 30 #define PER_CPU_VAR(var) %__percpu_seg:per_cpu__##var 31 #else /* ! SMP */ 32 #define PER_CPU(var, reg) \ 33 __percpu_mov_op $per_cpu__##var, reg 34 #define PER_CPU_VAR(var) per_cpu__##var 35 #endif /* SMP */ 36 37 #ifdef CONFIG_X86_64_SMP 38 #define INIT_PER_CPU_VAR(var) init_per_cpu__##var 39 #else 40 #define INIT_PER_CPU_VAR(var) per_cpu__##var 41 #endif 42 43 #else /* ...!ASSEMBLY */ 44 45 #include <linux/stringify.h> 46 47 #ifdef CONFIG_SMP 48 #define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x 49 #define __my_cpu_offset percpu_read(this_cpu_off) 50 #else 51 #define __percpu_arg(x) "%" #x 52 #endif 53 54 /* 55 * Initialized pointers to per-cpu variables needed for the boot 56 * processor need to use these macros to get the proper address 57 * offset from __per_cpu_load on SMP. 58 * 59 * There also must be an entry in vmlinux_64.lds.S 60 */ 61 #define DECLARE_INIT_PER_CPU(var) \ 62 extern typeof(per_cpu_var(var)) init_per_cpu_var(var) 63 64 #ifdef CONFIG_X86_64_SMP 65 #define init_per_cpu_var(var) init_per_cpu__##var 66 #else 67 #define init_per_cpu_var(var) per_cpu_var(var) 68 #endif 69 70 /* For arch-specific code, we can use direct single-insn ops (they 71 * don't give an lvalue though). */ 72 extern void __bad_percpu_size(void); 73 74 #define percpu_to_op(op, var, val) \ 75 do { \ 76 typedef typeof(var) T__; \ 77 if (0) { \ 78 T__ tmp__; \ 79 tmp__ = (val); \ 80 } \ 81 switch (sizeof(var)) { \ 82 case 1: \ 83 asm(op "b %1,"__percpu_arg(0) \ 84 : "+m" (var) \ 85 : "qi" ((T__)(val))); \ 86 break; \ 87 case 2: \ 88 asm(op "w %1,"__percpu_arg(0) \ 89 : "+m" (var) \ 90 : "ri" ((T__)(val))); \ 91 break; \ 92 case 4: \ 93 asm(op "l %1,"__percpu_arg(0) \ 94 : "+m" (var) \ 95 : "ri" ((T__)(val))); \ 96 break; \ 97 case 8: \ 98 asm(op "q %1,"__percpu_arg(0) \ 99 : "+m" (var) \ 100 : "re" ((T__)(val))); \ 101 break; \ 102 default: __bad_percpu_size(); \ 103 } \ 104 } while (0) 105 106 #define percpu_from_op(op, var) \ 107 ({ \ 108 typeof(var) ret__; \ 109 switch (sizeof(var)) { \ 110 case 1: \ 111 asm(op "b "__percpu_arg(1)",%0" \ 112 : "=q" (ret__) \ 113 : "m" (var)); \ 114 break; \ 115 case 2: \ 116 asm(op "w "__percpu_arg(1)",%0" \ 117 : "=r" (ret__) \ 118 : "m" (var)); \ 119 break; \ 120 case 4: \ 121 asm(op "l "__percpu_arg(1)",%0" \ 122 : "=r" (ret__) \ 123 : "m" (var)); \ 124 break; \ 125 case 8: \ 126 asm(op "q "__percpu_arg(1)",%0" \ 127 : "=r" (ret__) \ 128 : "m" (var)); \ 129 break; \ 130 default: __bad_percpu_size(); \ 131 } \ 132 ret__; \ 133 }) 134 135 #define percpu_read(var) percpu_from_op("mov", per_cpu__##var) 136 #define percpu_write(var, val) percpu_to_op("mov", per_cpu__##var, val) 137 #define percpu_add(var, val) percpu_to_op("add", per_cpu__##var, val) 138 #define percpu_sub(var, val) percpu_to_op("sub", per_cpu__##var, val) 139 #define percpu_and(var, val) percpu_to_op("and", per_cpu__##var, val) 140 #define percpu_or(var, val) percpu_to_op("or", per_cpu__##var, val) 141 #define percpu_xor(var, val) percpu_to_op("xor", per_cpu__##var, val) 142 143 /* This is not atomic against other CPUs -- CPU preemption needs to be off */ 144 #define x86_test_and_clear_bit_percpu(bit, var) \ 145 ({ \ 146 int old__; \ 147 asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \ 148 : "=r" (old__), "+m" (per_cpu__##var) \ 149 : "dIr" (bit)); \ 150 old__; \ 151 }) 152 153 #include <asm-generic/percpu.h> 154 155 /* We can use this directly for local CPU (faster). */ 156 DECLARE_PER_CPU(unsigned long, this_cpu_off); 157 158 #endif /* !__ASSEMBLY__ */ 159 160 #ifdef CONFIG_SMP 161 162 /* 163 * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu 164 * variables that are initialized and accessed before there are per_cpu 165 * areas allocated. 166 */ 167 168 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ 169 DEFINE_PER_CPU(_type, _name) = _initvalue; \ 170 __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \ 171 { [0 ... NR_CPUS-1] = _initvalue }; \ 172 __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map 173 174 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ 175 EXPORT_PER_CPU_SYMBOL(_name) 176 177 #define DECLARE_EARLY_PER_CPU(_type, _name) \ 178 DECLARE_PER_CPU(_type, _name); \ 179 extern __typeof__(_type) *_name##_early_ptr; \ 180 extern __typeof__(_type) _name##_early_map[] 181 182 #define early_per_cpu_ptr(_name) (_name##_early_ptr) 183 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx]) 184 #define early_per_cpu(_name, _cpu) \ 185 *(early_per_cpu_ptr(_name) ? \ 186 &early_per_cpu_ptr(_name)[_cpu] : \ 187 &per_cpu(_name, _cpu)) 188 189 #else /* !CONFIG_SMP */ 190 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ 191 DEFINE_PER_CPU(_type, _name) = _initvalue 192 193 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ 194 EXPORT_PER_CPU_SYMBOL(_name) 195 196 #define DECLARE_EARLY_PER_CPU(_type, _name) \ 197 DECLARE_PER_CPU(_type, _name) 198 199 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu) 200 #define early_per_cpu_ptr(_name) NULL 201 /* no early_per_cpu_map() */ 202 203 #endif /* !CONFIG_SMP */ 204 205 #endif /* _ASM_X86_PERCPU_H */ 206