1 #ifndef __ALPHA_PERCPU_H 2 #define __ALPHA_PERCPU_H 3 4 #include <linux/compiler.h> 5 #include <linux/threads.h> 6 #include <linux/percpu-defs.h> 7 8 /* 9 * Determine the real variable name from the name visible in the 10 * kernel sources. 11 */ 12 #define per_cpu_var(var) per_cpu__##var 13 14 #ifdef CONFIG_SMP 15 16 /* 17 * per_cpu_offset() is the offset that has to be added to a 18 * percpu variable to get to the instance for a certain processor. 19 */ 20 extern unsigned long __per_cpu_offset[NR_CPUS]; 21 22 #define per_cpu_offset(x) (__per_cpu_offset[x]) 23 24 #define __my_cpu_offset per_cpu_offset(raw_smp_processor_id()) 25 #ifdef CONFIG_DEBUG_PREEMPT 26 #define my_cpu_offset per_cpu_offset(smp_processor_id()) 27 #else 28 #define my_cpu_offset __my_cpu_offset 29 #endif 30 31 #ifndef MODULE 32 #define SHIFT_PERCPU_PTR(var, offset) RELOC_HIDE(&per_cpu_var(var), (offset)) 33 #define PER_CPU_ATTRIBUTES 34 #else 35 /* 36 * To calculate addresses of locally defined variables, GCC uses 32-bit 37 * displacement from the GP. Which doesn't work for per cpu variables in 38 * modules, as an offset to the kernel per cpu area is way above 4G. 39 * 40 * This forces allocation of a GOT entry for per cpu variable using 41 * ldq instruction with a 'literal' relocation. 42 */ 43 #define SHIFT_PERCPU_PTR(var, offset) ({ \ 44 extern int simple_identifier_##var(void); \ 45 unsigned long __ptr, tmp_gp; \ 46 asm ( "br %1, 1f \n\ 47 1: ldgp %1, 0(%1) \n\ 48 ldq %0, per_cpu__" #var"(%1)\t!literal" \ 49 : "=&r"(__ptr), "=&r"(tmp_gp)); \ 50 (typeof(&per_cpu_var(var)))(__ptr + (offset)); }) 51 52 #define PER_CPU_ATTRIBUTES __used 53 54 #endif /* MODULE */ 55 56 /* 57 * A percpu variable may point to a discarded regions. The following are 58 * established ways to produce a usable pointer from the percpu variable 59 * offset. 60 */ 61 #define per_cpu(var, cpu) \ 62 (*SHIFT_PERCPU_PTR(var, per_cpu_offset(cpu))) 63 #define __get_cpu_var(var) \ 64 (*SHIFT_PERCPU_PTR(var, my_cpu_offset)) 65 #define __raw_get_cpu_var(var) \ 66 (*SHIFT_PERCPU_PTR(var, __my_cpu_offset)) 67 68 #else /* ! SMP */ 69 70 #define per_cpu(var, cpu) (*((void)(cpu), &per_cpu_var(var))) 71 #define __get_cpu_var(var) per_cpu_var(var) 72 #define __raw_get_cpu_var(var) per_cpu_var(var) 73 74 #define PER_CPU_ATTRIBUTES 75 76 #endif /* SMP */ 77 78 #ifdef CONFIG_SMP 79 #define PER_CPU_BASE_SECTION ".data.percpu" 80 #else 81 #define PER_CPU_BASE_SECTION ".data" 82 #endif 83 84 #ifdef CONFIG_SMP 85 86 #ifdef MODULE 87 #define PER_CPU_SHARED_ALIGNED_SECTION "" 88 #else 89 #define PER_CPU_SHARED_ALIGNED_SECTION ".shared_aligned" 90 #endif 91 #define PER_CPU_FIRST_SECTION ".first" 92 93 #else 94 95 #define PER_CPU_SHARED_ALIGNED_SECTION "" 96 #define PER_CPU_FIRST_SECTION "" 97 98 #endif 99 100 #define PER_CPU_ATTRIBUTES 101 102 #endif /* __ALPHA_PERCPU_H */ 103