include/asm-x86/percpu_32.h

   1 #ifndef __ARCH_I386_PERCPU__
   2 #define __ARCH_I386_PERCPU__
   3
   4 #ifdef __ASSEMBLY__
   5
   6 /*
   7  * PER_CPU finds an address of a per-cpu variable.
   8  *
   9  * Args:
  10  *    var - variable name
  11  *    reg - 32bit register
  12  *
  13  * The resulting address is stored in the "reg" argument.
  14  *
  15  * Example:
  16  *    PER_CPU(cpu_gdt_descr, %ebx)
  17  */
  18 #ifdef CONFIG_SMP
  19 #define PER_CPU(var, reg)                               \
  20         movl %fs:per_cpu__##this_cpu_off, reg;          \
  21         lea per_cpu__##var(reg), reg
  22 #define PER_CPU_VAR(var)        %fs:per_cpu__##var
  23 #else /* ! SMP */
  24 #define PER_CPU(var, reg)                       \
  25         movl $per_cpu__##var, reg
  26 #define PER_CPU_VAR(var)        per_cpu__##var
  27 #endif  /* SMP */
  28
  29 #else /* ...!ASSEMBLY */
  30
  31 /*
  32  * PER_CPU finds an address of a per-cpu variable.
  33  *
  34  * Args:
  35  *    var - variable name
  36  *    cpu - 32bit register containing the current CPU number
  37  *
  38  * The resulting address is stored in the "cpu" argument.
  39  *
  40  * Example:
  41  *    PER_CPU(cpu_gdt_descr, %ebx)
  42  */
  43 #ifdef CONFIG_SMP
  44
  45 #define __my_cpu_offset x86_read_percpu(this_cpu_off)
  46
  47 /* A macro to avoid #include hell... */
  48 #define percpu_modcopy(pcpudst, src, size)                      \
  49 do {                                                            \
  50         unsigned int __i;                                       \
  51         for_each_possible_cpu(__i)                              \
  52                 memcpy((pcpudst)+__per_cpu_offset[__i],         \
  53                        (src), (size));                          \
  54 } while (0)
  55
  56 /* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
  57 #define __percpu_seg "%%fs:"
  58
  59 #else  /* !SMP */
  60
  61 #define __percpu_seg ""
  62
  63 #endif  /* SMP */
  64
  65 #include <asm-generic/percpu.h>
  66
  67 /* We can use this directly for local CPU (faster). */
  68 DECLARE_PER_CPU(unsigned long, this_cpu_off);
  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) { T__ tmp__; tmp__ = (val); }            \
  78                 switch (sizeof(var)) {                          \
  79                 case 1:                                         \
  80                         asm(op "b %1,"__percpu_seg"%0"          \
  81                             : "+m" (var)                        \
  82                             :"ri" ((T__)val));                  \
  83                         break;                                  \
  84                 case 2:                                         \
  85                         asm(op "w %1,"__percpu_seg"%0"          \
  86                             : "+m" (var)                        \
  87                             :"ri" ((T__)val));                  \
  88                         break;                                  \
  89                 case 4:                                         \
  90                         asm(op "l %1,"__percpu_seg"%0"          \
  91                             : "+m" (var)                        \
  92                             :"ri" ((T__)val));                  \
  93                         break;                                  \
  94                 default: __bad_percpu_size();                   \
  95                 }                                               \
  96         } while (0)
  97
  98 #define percpu_from_op(op,var)                                  \
  99         ({                                                      \
 100                 typeof(var) ret__;                              \
 101                 switch (sizeof(var)) {                          \
 102                 case 1:                                         \
 103                         asm(op "b "__percpu_seg"%1,%0"          \
 104                             : "=r" (ret__)                      \
 105                             : "m" (var));                       \
 106                         break;                                  \
 107                 case 2:                                         \
 108                         asm(op "w "__percpu_seg"%1,%0"          \
 109                             : "=r" (ret__)                      \
 110                             : "m" (var));                       \
 111                         break;                                  \
 112                 case 4:                                         \
 113                         asm(op "l "__percpu_seg"%1,%0"          \
 114                             : "=r" (ret__)                      \
 115                             : "m" (var));                       \
 116                         break;                                  \
 117                 default: __bad_percpu_size();                   \
 118                 }                                               \
 119                 ret__; })
 120
 121 #define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
 122 #define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val)
 123 #define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val)
 124 #define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val)
 125 #define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val)
 126 #endif /* !__ASSEMBLY__ */
 127
 128 #endif /* __ARCH_I386_PERCPU__ */