diff options
Diffstat (limited to 'include/asm-i386/percpu.h')
| -rw-r--r-- | include/asm-i386/percpu.h | 132 |
1 files changed, 123 insertions, 9 deletions
diff --git a/include/asm-i386/percpu.h b/include/asm-i386/percpu.h index a10e7c6..c5f12f0 100644 --- a/include/asm-i386/percpu.h +++ b/include/asm-i386/percpu.h @@ -1,9 +1,30 @@ #ifndef __ARCH_I386_PERCPU__ #define __ARCH_I386_PERCPU__ -#ifndef __ASSEMBLY__ -#include <asm-generic/percpu.h> -#else +#ifdef __ASSEMBLY__ + +/* + * PER_CPU finds an address of a per-cpu variable. + * + * Args: + * var - variable name + * reg - 32bit register + * + * The resulting address is stored in the "reg" argument. + * + * Example: + * PER_CPU(cpu_gdt_descr, %ebx) + */ +#ifdef CONFIG_SMP +#define PER_CPU(var, reg) \ + movl %fs:per_cpu__this_cpu_off, reg; \ + addl $per_cpu__##var, reg +#else /* ! SMP */ +#define PER_CPU(var, reg) \ + movl $per_cpu__##var, reg; +#endif /* SMP */ + +#else /* ...!ASSEMBLY */ /* * PER_CPU finds an address of a per-cpu variable. @@ -18,14 +39,107 @@ * PER_CPU(cpu_gdt_descr, %ebx) */ #ifdef CONFIG_SMP -#define PER_CPU(var, cpu) \ - movl __per_cpu_offset(,cpu,4), cpu; \ - addl $per_cpu__##var, cpu; -#else /* ! SMP */ -#define PER_CPU(var, cpu) \ - movl $per_cpu__##var, cpu; +/* Same as generic implementation except for optimized local access. */ +#define __GENERIC_PER_CPU + +/* This is used for other cpus to find our section. */ +extern unsigned long __per_cpu_offset[]; + +/* Separate out the type, so (int[3], foo) works. */ +#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu__##name +#define DEFINE_PER_CPU(type, name) \ + __attribute__((__section__(".data.percpu"))) __typeof__(type) per_cpu__##name + +/* We can use this directly for local CPU (faster). */ +DECLARE_PER_CPU(unsigned long, this_cpu_off); + +/* var is in discarded region: offset to particular copy we want */ +#define per_cpu(var, cpu) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, __per_cpu_offset[cpu]); })) + +#define __raw_get_cpu_var(var) (*({ \ + extern int simple_indentifier_##var(void); \ + RELOC_HIDE(&per_cpu__##var, x86_read_percpu(this_cpu_off)); \ +})) + +#define __get_cpu_var(var) __raw_get_cpu_var(var) + +/* A macro to avoid #include hell... */ +#define percpu_modcopy(pcpudst, src, size) \ +do { \ + unsigned int __i; \ + for_each_possible_cpu(__i) \ + memcpy((pcpudst)+__per_cpu_offset[__i], \ + (src), (size)); \ +} while (0) + +#define EXPORT_PER_CPU_SYMBOL(var) EXPORT_SYMBOL(per_cpu__##var) +#define EXPORT_PER_CPU_SYMBOL_GPL(var) EXPORT_SYMBOL_GPL(per_cpu__##var) + +/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */ +#define __percpu_seg "%%fs:" +#else /* !SMP */ +#include <asm-generic/percpu.h> +#define __percpu_seg "" #endif /* SMP */ +/* For arch-specific code, we can use direct single-insn ops (they + * don't give an lvalue though). */ +extern void __bad_percpu_size(void); + +#define percpu_to_op(op,var,val) \ + do { \ + typedef typeof(var) T__; \ + if (0) { T__ tmp__; tmp__ = (val); } \ + switch (sizeof(var)) { \ + case 1: \ + asm(op "b %1,"__percpu_seg"%0" \ + : "+m" (var) \ + :"ri" ((T__)val)); \ + break; \ + case 2: \ + asm(op "w %1,"__percpu_seg"%0" \ + : "+m" (var) \ + :"ri" ((T__)val)); \ + break; \ + case 4: \ + asm(op "l %1,"__percpu_seg"%0" \ + : "+m" (var) \ + :"ri" ((T__)val)); \ + break; \ + default: __bad_percpu_size(); \ + } \ + } while (0) + +#define percpu_from_op(op,var) \ + ({ \ + typeof(var) ret__; \ + switch (sizeof(var)) { \ + case 1: \ + asm(op "b "__percpu_seg"%1,%0" \ + : "=r" (ret__) \ + : "m" (var)); \ + break; \ + case 2: \ + asm(op "w "__percpu_seg"%1,%0" \ + : "=r" (ret__) \ + : "m" (var)); \ + break; \ + case 4: \ + asm(op "l "__percpu_seg"%1,%0" \ + : "=r" (ret__) \ + : "m" (var)); \ + break; \ + default: __bad_percpu_size(); \ + } \ + ret__; }) + +#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var) +#define x86_write_percpu(var,val) percpu_to_op("mov", per_cpu__##var, val) +#define x86_add_percpu(var,val) percpu_to_op("add", per_cpu__##var, val) +#define x86_sub_percpu(var,val) percpu_to_op("sub", per_cpu__##var, val) +#define x86_or_percpu(var,val) percpu_to_op("or", per_cpu__##var, val) #endif /* !__ASSEMBLY__ */ #endif /* __ARCH_I386_PERCPU__ */ |