1 #ifndef _ASM_X86_PERCPU_H 2 #define _ASM_X86_PERCPU_H 3 4 #ifdef CONFIG_X86_64 5 #include <linux/compiler.h> 6 7 /* Same as asm-generic/percpu.h, except that we store the per cpu offset 8 in the PDA. Longer term the PDA and every per cpu variable 9 should be just put into a single section and referenced directly 10 from %gs */ 11 12 #ifdef CONFIG_SMP 13 #include <asm/pda.h> 14 15 #define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset) 16 #define __my_cpu_offset read_pda(data_offset) 17 18 #define per_cpu_offset(x) (__per_cpu_offset(x)) 19 20 #endif 21 #include <asm-generic/percpu.h> 22 23 DECLARE_PER_CPU(struct x8664_pda, pda); 24 25 /* 26 * These are supposed to be implemented as a single instruction which 27 * operates on the per-cpu data base segment. x86-64 doesn't have 28 * that yet, so this is a fairly inefficient workaround for the 29 * meantime. The single instruction is atomic with respect to 30 * preemption and interrupts, so we need to explicitly disable 31 * interrupts here to achieve the same effect. However, because it 32 * can be used from within interrupt-disable/enable, we can't actually 33 * disable interrupts; disabling preemption is enough. 34 */ 35 #define x86_read_percpu(var) \ 36 ({ \ 37 typeof(per_cpu_var(var)) __tmp; \ 38 preempt_disable(); \ 39 __tmp = __get_cpu_var(var); \ 40 preempt_enable(); \ 41 __tmp; \ 42 }) 43 44 #define x86_write_percpu(var, val) \ 45 do { \ 46 preempt_disable(); \ 47 __get_cpu_var(var) = (val); \ 48 preempt_enable(); \ 49 } while(0) 50 51 #else /* CONFIG_X86_64 */ 52 53 #ifdef __ASSEMBLY__ 54 55 /* 56 * PER_CPU finds an address of a per-cpu variable. 57 * 58 * Args: 59 * var - variable name 60 * reg - 32bit register 61 * 62 * The resulting address is stored in the "reg" argument. 63 * 64 * Example: 65 * PER_CPU(cpu_gdt_descr, %ebx) 66 */ 67 #ifdef CONFIG_SMP 68 #define PER_CPU(var, reg) \ 69 movl %fs:per_cpu__##this_cpu_off, reg; \ 70 lea per_cpu__##var(reg), reg 71 #define PER_CPU_VAR(var) %fs:per_cpu__##var 72 #else /* ! SMP */ 73 #define PER_CPU(var, reg) \ 74 movl $per_cpu__##var, reg 75 #define PER_CPU_VAR(var) per_cpu__##var 76 #endif /* SMP */ 77 78 #else /* ...!ASSEMBLY */ 79 80 /* 81 * PER_CPU finds an address of a per-cpu variable. 82 * 83 * Args: 84 * var - variable name 85 * cpu - 32bit register containing the current CPU number 86 * 87 * The resulting address is stored in the "cpu" argument. 88 * 89 * Example: 90 * PER_CPU(cpu_gdt_descr, %ebx) 91 */ 92 #ifdef CONFIG_SMP 93 94 #define __my_cpu_offset x86_read_percpu(this_cpu_off) 95 96 /* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */ 97 #define __percpu_seg "%%fs:" 98 99 #else /* !SMP */ 100 101 #define __percpu_seg "" 102 103 #endif /* SMP */ 104 105 #include <asm-generic/percpu.h> 106 107 /* We can use this directly for local CPU (faster). */ 108 DECLARE_PER_CPU(unsigned long, this_cpu_off); 109 110 /* For arch-specific code, we can use direct single-insn ops (they 111 * don't give an lvalue though). */ 112 extern void __bad_percpu_size(void); 113 114 #define percpu_to_op(op, var, val) \ 115 do { \ 116 typedef typeof(var) T__; \ 117 if (0) { \ 118 T__ tmp__; \ 119 tmp__ = (val); \ 120 } \ 121 switch (sizeof(var)) { \ 122 case 1: \ 123 asm(op "b %1,"__percpu_seg"%0" \ 124 : "+m" (var) \ 125 : "ri" ((T__)val)); \ 126 break; \ 127 case 2: \ 128 asm(op "w %1,"__percpu_seg"%0" \ 129 : "+m" (var) \ 130 : "ri" ((T__)val)); \ 131 break; \ 132 case 4: \ 133 asm(op "l %1,"__percpu_seg"%0" \ 134 : "+m" (var) \ 135 : "ri" ((T__)val)); \ 136 break; \ 137 default: __bad_percpu_size(); \ 138 } \ 139 } while (0) 140 141 #define percpu_from_op(op, var) \ 142 ({ \ 143 typeof(var) ret__; \ 144 switch (sizeof(var)) { \ 145 case 1: \ 146 asm(op "b "__percpu_seg"%1,%0" \ 147 : "=r" (ret__) \ 148 : "m" (var)); \ 149 break; \ 150 case 2: \ 151 asm(op "w "__percpu_seg"%1,%0" \ 152 : "=r" (ret__) \ 153 : "m" (var)); \ 154 break; \ 155 case 4: \ 156 asm(op "l "__percpu_seg"%1,%0" \ 157 : "=r" (ret__) \ 158 : "m" (var)); \ 159 break; \ 160 default: __bad_percpu_size(); \ 161 } \ 162 ret__; \ 163 }) 164 165 #define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var) 166 #define x86_write_percpu(var, val) percpu_to_op("mov", per_cpu__##var, val) 167 #define x86_add_percpu(var, val) percpu_to_op("add", per_cpu__##var, val) 168 #define x86_sub_percpu(var, val) percpu_to_op("sub", per_cpu__##var, val) 169 #define x86_or_percpu(var, val) percpu_to_op("or", per_cpu__##var, val) 170 #endif /* !__ASSEMBLY__ */ 171 #endif /* !CONFIG_X86_64 */ 172 173 #ifdef CONFIG_SMP 174 175 /* 176 * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu 177 * variables that are initialized and accessed before there are per_cpu 178 * areas allocated. 179 */ 180 181 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ 182 DEFINE_PER_CPU(_type, _name) = _initvalue; \ 183 __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \ 184 { [0 ... NR_CPUS-1] = _initvalue }; \ 185 __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map 186 187 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ 188 EXPORT_PER_CPU_SYMBOL(_name) 189 190 #define DECLARE_EARLY_PER_CPU(_type, _name) \ 191 DECLARE_PER_CPU(_type, _name); \ 192 extern __typeof__(_type) *_name##_early_ptr; \ 193 extern __typeof__(_type) _name##_early_map[] 194 195 #define early_per_cpu_ptr(_name) (_name##_early_ptr) 196 #define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx]) 197 #define early_per_cpu(_name, _cpu) \ 198 (early_per_cpu_ptr(_name) ? \ 199 early_per_cpu_ptr(_name)[_cpu] : \ 200 per_cpu(_name, _cpu)) 201 202 #else /* !CONFIG_SMP */ 203 #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ 204 DEFINE_PER_CPU(_type, _name) = _initvalue 205 206 #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ 207 EXPORT_PER_CPU_SYMBOL(_name) 208 209 #define DECLARE_EARLY_PER_CPU(_type, _name) \ 210 DECLARE_PER_CPU(_type, _name) 211 212 #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu) 213 #define early_per_cpu_ptr(_name) NULL 214 /* no early_per_cpu_map() */ 215 216 #endif /* !CONFIG_SMP */ 217 218 #endif /* _ASM_X86_PERCPU_H */ 219