1 #ifndef X86_64_PDA_H 2 #define X86_64_PDA_H 3 4 #ifndef __ASSEMBLY__ 5 #include <linux/stddef.h> 6 #include <linux/types.h> 7 #include <linux/cache.h> 8 #include <asm/page.h> 9 10 /* Per processor datastructure. %gs points to it while the kernel runs */ 11 struct x8664_pda { 12 struct task_struct *pcurrent; /* 0 Current process */ 13 unsigned long data_offset; /* 8 Per cpu data offset from linker 14 address */ 15 unsigned long kernelstack; /* 16 top of kernel stack for current */ 16 unsigned long oldrsp; /* 24 user rsp for system call */ 17 int irqcount; /* 32 Irq nesting counter. Starts with -1 */ 18 int cpunumber; /* 36 Logical CPU number */ 19 #ifdef CONFIG_CC_STACKPROTECTOR 20 unsigned long stack_canary; /* 40 stack canary value */ 21 /* gcc-ABI: this canary MUST be at 22 offset 40!!! */ 23 #endif 24 char *irqstackptr; 25 int nodenumber; /* number of current node */ 26 unsigned int __softirq_pending; 27 unsigned int __nmi_count; /* number of NMI on this CPUs */ 28 short mmu_state; 29 short isidle; 30 struct mm_struct *active_mm; 31 unsigned apic_timer_irqs; 32 unsigned irq0_irqs; 33 unsigned irq_resched_count; 34 unsigned irq_call_count; 35 unsigned irq_tlb_count; 36 unsigned irq_thermal_count; 37 unsigned irq_threshold_count; 38 unsigned irq_spurious_count; 39 } ____cacheline_aligned_in_smp; 40 41 extern struct x8664_pda *_cpu_pda[]; 42 extern struct x8664_pda boot_cpu_pda[]; 43 44 #define cpu_pda(i) (_cpu_pda[i]) 45 46 /* 47 * There is no fast way to get the base address of the PDA, all the accesses 48 * have to mention %fs/%gs. So it needs to be done this Torvaldian way. 49 */ 50 extern void __bad_pda_field(void) __attribute__((noreturn)); 51 52 /* 53 * proxy_pda doesn't actually exist, but tell gcc it is accessed for 54 * all PDA accesses so it gets read/write dependencies right. 55 */ 56 extern struct x8664_pda _proxy_pda; 57 58 #define pda_offset(field) offsetof(struct x8664_pda, field) 59 60 #define pda_to_op(op,field,val) do { \ 61 typedef typeof(_proxy_pda.field) T__; \ 62 if (0) { T__ tmp__; tmp__ = (val); } /* type checking */ \ 63 switch (sizeof(_proxy_pda.field)) { \ 64 case 2: \ 65 asm(op "w %1,%%gs:%c2" : \ 66 "+m" (_proxy_pda.field) : \ 67 "ri" ((T__)val), \ 68 "i"(pda_offset(field))); \ 69 break; \ 70 case 4: \ 71 asm(op "l %1,%%gs:%c2" : \ 72 "+m" (_proxy_pda.field) : \ 73 "ri" ((T__)val), \ 74 "i" (pda_offset(field))); \ 75 break; \ 76 case 8: \ 77 asm(op "q %1,%%gs:%c2": \ 78 "+m" (_proxy_pda.field) : \ 79 "ri" ((T__)val), \ 80 "i"(pda_offset(field))); \ 81 break; \ 82 default: \ 83 __bad_pda_field(); \ 84 } \ 85 } while (0) 86 87 #define pda_from_op(op,field) ({ \ 88 typeof(_proxy_pda.field) ret__; \ 89 switch (sizeof(_proxy_pda.field)) { \ 90 case 2: \ 91 asm(op "w %%gs:%c1,%0" : \ 92 "=r" (ret__) : \ 93 "i" (pda_offset(field)), \ 94 "m" (_proxy_pda.field)); \ 95 break; \ 96 case 4: \ 97 asm(op "l %%gs:%c1,%0": \ 98 "=r" (ret__): \ 99 "i" (pda_offset(field)), \ 100 "m" (_proxy_pda.field)); \ 101 break; \ 102 case 8: \ 103 asm(op "q %%gs:%c1,%0": \ 104 "=r" (ret__) : \ 105 "i" (pda_offset(field)), \ 106 "m" (_proxy_pda.field)); \ 107 break; \ 108 default: \ 109 __bad_pda_field(); \ 110 } \ 111 ret__; }) 112 113 #define read_pda(field) pda_from_op("mov",field) 114 #define write_pda(field,val) pda_to_op("mov",field,val) 115 #define add_pda(field,val) pda_to_op("add",field,val) 116 #define sub_pda(field,val) pda_to_op("sub",field,val) 117 #define or_pda(field,val) pda_to_op("or",field,val) 118 119 /* This is not atomic against other CPUs -- CPU preemption needs to be off */ 120 #define test_and_clear_bit_pda(bit,field) ({ \ 121 int old__; \ 122 asm volatile("btr %2,%%gs:%c3\n\tsbbl %0,%0" \ 123 : "=r" (old__), "+m" (_proxy_pda.field) \ 124 : "dIr" (bit), "i" (pda_offset(field)) : "memory"); \ 125 old__; \ 126 }) 127 128 #endif 129 130 #define PDA_STACKOFFSET (5*8) 131 132 #endif 133