From 024b246ed24492d6c2ee14c34d742b137fce1b94 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Fri, 15 Aug 2008 09:19:40 -0700 Subject: alpha: move include/asm-alpha to arch/alpha/include/asm Sam Ravnborg did the build-test that the direct header file move works, I'm just committing it. This is a pure move: mkdir arch/alpha/include git mv include/asm-alpha arch/alpha/include/asm with no other changes. Requested-and-tested-by: Sam Ravnborg Cc: Richard Henderson Cc: Ivan Kokshaysky Signed-off-by: Linus Torvalds --- arch/alpha/include/asm/percpu.h | 78 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 78 insertions(+) create mode 100644 arch/alpha/include/asm/percpu.h (limited to 'arch/alpha/include/asm/percpu.h') diff --git a/arch/alpha/include/asm/percpu.h b/arch/alpha/include/asm/percpu.h new file mode 100644 index 00000000000..3495e8e00d7 --- /dev/null +++ b/arch/alpha/include/asm/percpu.h @@ -0,0 +1,78 @@ +#ifndef __ALPHA_PERCPU_H +#define __ALPHA_PERCPU_H +#include +#include + +/* + * Determine the real variable name from the name visible in the + * kernel sources. + */ +#define per_cpu_var(var) per_cpu__##var + +#ifdef CONFIG_SMP + +/* + * per_cpu_offset() is the offset that has to be added to a + * percpu variable to get to the instance for a certain processor. + */ +extern unsigned long __per_cpu_offset[NR_CPUS]; + +#define per_cpu_offset(x) (__per_cpu_offset[x]) + +#define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) +#ifdef CONFIG_DEBUG_PREEMPT +#define my_cpu_offset per_cpu_offset(smp_processor_id()) +#else +#define my_cpu_offset __my_cpu_offset +#endif + +#ifndef MODULE +#define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset)) +#define PER_CPU_ATTRIBUTES +#else +/* + * To calculate addresses of locally defined variables, GCC uses 32-bit + * displacement from the GP. Which doesn't work for per cpu variables in + * modules, as an offset to the kernel per cpu area is way above 4G. + * + * This forces allocation of a GOT entry for per cpu variable using + * ldq instruction with a 'literal' relocation. + */ +#define SHIFT_PERCPU_PTR(var, offset) ({ \ + extern int simple_identifier_##var(void); \ + unsigned long __ptr, tmp_gp; \ + asm ( "br %1, 1f \n\ + 1: ldgp %1, 0(%1) \n\ + ldq %0, per_cpu__" #var"(%1)\t!literal" \ + : "=&r"(__ptr), "=&r"(tmp_gp)); \ + (typeof(&per_cpu_var(var)))(__ptr + (offset)); }) + +#define PER_CPU_ATTRIBUTES __used + +#endif /* MODULE */ + +/* + * A percpu variable may point to a discarded regions. The following are + * established ways to produce a usable pointer from the percpu variable + * offset. + */ +#define per_cpu(var, cpu) \ + (*SHIFT_PERCPU_PTR(var, per_cpu_offset(cpu))) +#define __get_cpu_var(var) \ + (*SHIFT_PERCPU_PTR(var, my_cpu_offset)) +#define __raw_get_cpu_var(var) \ + (*SHIFT_PERCPU_PTR(var, __my_cpu_offset)) + +#else /* ! SMP */ + +#define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var))) +#define __get_cpu_var(var) per_cpu_var(var) +#define __raw_get_cpu_var(var) per_cpu_var(var) + +#define PER_CPU_ATTRIBUTES + +#endif /* SMP */ + +#define DECLARE_PER_CPU(type, name) extern __typeof__(type) per_cpu_var(name) + +#endif /* __ALPHA_PERCPU_H */ -- cgit v1.2.3-70-g09d2