#ifndef __ASM_SYSTEM_H #define __ASM_SYSTEM_H #include #include #include #ifdef __KERNEL__ #ifdef CONFIG_SMP #define LOCK_PREFIX "lock ; " #else #define LOCK_PREFIX "" #endif #define __STR(x) #x #define STR(x) __STR(x) #define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t" #define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t" /* frame pointer must be last for get_wchan */ #define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t" #define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\n\t" #define __EXTRA_CLOBBER \ ,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15" #define switch_to(prev,next,last) \ asm volatile(SAVE_CONTEXT \ "movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \ "movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \ "call __switch_to\n\t" \ ".globl thread_return\n" \ "thread_return:\n\t" \ "movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \ "movq %P[thread_info](%%rsi),%%r8\n\t" \ LOCK "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \ "movq %%rax,%%rdi\n\t" \ "jc ret_from_fork\n\t" \ RESTORE_CONTEXT \ : "=a" (last) \ : [next] "S" (next), [prev] "D" (prev), \ [threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \ [ti_flags] "i" (offsetof(struct thread_info, flags)),\ [tif_fork] "i" (TIF_FORK), \ [thread_info] "i" (offsetof(struct task_struct, thread_info)), \ [pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)) \ : "memory", "cc" __EXTRA_CLOBBER) extern void load_gs_index(unsigned); /* * Load a segment. Fall back on loading the zero * segment if something goes wrong.. */ #define loadsegment(seg,value) \ asm volatile("\n" \ "1:\t" \ "movl %k0,%%" #seg "\n" \ "2:\n" \ ".section .fixup,\"ax\"\n" \ "3:\t" \ "movl %1,%%" #seg "\n\t" \ "jmp 2b\n" \ ".previous\n" \ ".section __ex_table,\"a\"\n\t" \ ".align 8\n\t" \ ".quad 1b,3b\n" \ ".previous" \ : :"r" (value), "r" (0)) #ifdef __KERNEL__ struct alt_instr { __u8 *instr; /* original instruction */ __u8 *replacement; __u8 cpuid; /* cpuid bit set for replacement */ __u8 instrlen; /* length of original instruction */ __u8 replacementlen; /* length of new instruction, <= instrlen */ __u8 pad[5]; }; #endif /* * Alternative instructions for different CPU types or capabilities. * * This allows to use optimized instructions even on generic binary * kernels. * * length of oldinstr must be longer or equal the length of newinstr * It can be padded with nops as needed. * * For non barrier like inlines please define new variants * without volatile and memory clobber. */ #define alternative(oldinstr, newinstr, feature) \ asm volatile ("661:\n\t" oldinstr "\n662:\n" \ ".section .altinstructions,\"a\"\n" \ " .align 8\n" \ " .quad 661b\n" /* label */ \ " .quad 663f\n" /* new instruction */ \ " .byte %c0\n" /* feature bit */ \ " .byte 662b-661b\n" /* sourcelen */ \ " .byte 664f-663f\n" /* replacementlen */ \ ".previous\n" \ ".section .altinstr_replacement,\"ax\"\n" \ "663:\n\t" newinstr "\n664:\n" /* replacement */ \ ".previous" :: "i" (feature) : "memory") /* * Alternative inline assembly with input. * * Peculiarities: * No memory clobber here. * Argument numbers start with 1. * Best is to use constraints that are fixed size (like (%1) ... "r") * If you use variable sized constraints like "m" or "g" in the * replacement make sure to pad to the worst case length. */ #define alternative_input(oldinstr, newinstr, feature, input...) \ asm volatile ("661:\n\t" oldinstr "\n662:\n" \ ".section .altinstructions,\"a\"\n" \ " .align 8\n" \ " .quad 661b\n" /* label */ \ " .quad 663f\n" /* new instruction */ \ " .byte %c0\n" /* feature bit */ \ " .byte 662b-661b\n" /* sourcelen */ \ " .byte 664f-663f\n" /* replacementlen */ \ ".previous\n" \ ".section .altinstr_replacement,\"ax\"\n" \ "663:\n\t" newinstr "\n664:\n" /* replacement */ \ ".previous" :: "i" (feature), ##input) /* Like alternative_input, but with a single output argument */ #define alternative_io(oldinstr, newinstr, feature, output, input...) \ asm volatile ("661:\n\t" oldinstr "\n662:\n" \ ".section .altinstructions,\"a\"\n" \ " .align 8\n" \ " .quad 661b\n" /* label */ \ " .quad 663f\n" /* new instruction */ \ " .byte %c[feat]\n" /* feature bit */ \ " .byte 662b-661b\n" /* sourcelen */ \ " .byte 664f-663f\n" /* replacementlen */ \ ".previous\n" \ ".section .altinstr_replacement,\"ax\"\n" \ "663:\n\t" newinstr "\n664:\n" /* replacement */ \ ".previous" : output : [feat] "i" (feature), ##input) /* * Clear and set 'TS' bit respectively */ #define clts() __asm__ __volatile__ ("clts") static inline unsigned long read_cr0(void) { unsigned long cr0; asm volatile("movq %%cr0,%0" : "=r" (cr0)); return cr0; } static inline void write_cr0(unsigned long val) { asm volatile("movq %0,%%cr0" :: "r" (val)); } static inline unsigned long read_cr3(void) { unsigned long cr3; asm("movq %%cr3,%0" : "=r" (cr3)); return cr3; } static inline unsigned long read_cr4(void) { unsigned long cr4; asm("movq %%cr4,%0" : "=r" (cr4)); return cr4; } static inline void write_cr4(unsigned long val) { asm volatile("movq %0,%%cr4" :: "r" (val)); } #define stts() write_cr0(8 | read_cr0()) #define wbinvd() \ __asm__ __volatile__ ("wbinvd": : :"memory"); /* * On SMP systems, when the scheduler does migration-cost autodetection, * it needs a way to flush as much of the CPU's caches as possible. */ static inline void sched_cacheflush(void) { wbinvd(); } #endif /* __KERNEL__ */ #define nop() __asm__ __volatile__ ("nop") #define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr)))) #define tas(ptr) (xchg((ptr),1)) #define __xg(x) ((volatile long *)(x)) static inline void set_64bit(volatile unsigned long *ptr, unsigned long val) { *ptr = val; } #define _set_64bit set_64bit /* * Note: no "lock" prefix even on SMP: xchg always implies lock anyway * Note 2: xchg has side effect, so that attribute volatile is necessary, * but generally the primitive is invalid, *ptr is output argument. --ANK */ static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size) { switch (size) { case 1: __asm__ __volatile__("xchgb %b0,%1" :"=q" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; case 2: __asm__ __volatile__("xchgw %w0,%1" :"=r" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; case 4: __asm__ __volatile__("xchgl %k0,%1" :"=r" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; case 8: __asm__ __volatile__("xchgq %0,%1" :"=r" (x) :"m" (*__xg(ptr)), "0" (x) :"memory"); break; } return x; } /* * Atomic compare and exchange. Compare OLD with MEM, if identical, * store NEW in MEM. Return the initial value in MEM. Success is * indicated by comparing RETURN with OLD. */ #define __HAVE_ARCH_CMPXCHG 1 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old, unsigned long new, int size) { unsigned long prev; switch (size) { case 1: __asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2" : "=a"(prev) : "q"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 2: __asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 4: __asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; case 8: __asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2" : "=a"(prev) : "r"(new), "m"(*__xg(ptr)), "0"(old) : "memory"); return prev; } return old; } #define cmpxchg(ptr,o,n)\ ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\ (unsigned long)(n),sizeof(*(ptr)))) #ifdef CONFIG_SMP #define smp_mb() mb() #define smp_rmb() rmb() #define smp_wmb() wmb() #define smp_read_barrier_depends() do {} while(0) #else #define smp_mb() barrier() #define smp_rmb() barrier() #define smp_wmb() barrier() #define smp_read_barrier_depends() do {} while(0) #endif /* * Force strict CPU ordering. * And yes, this is required on UP too when we're talking * to devices. */ #define mb() asm volatile("mfence":::"memory") #define rmb() asm volatile("lfence":::"memory") #ifdef CONFIG_UNORDERED_IO #define wmb() asm volatile("sfence" ::: "memory") #else #define wmb() asm volatile("" ::: "memory") #endif #define read_barrier_depends() do {} while(0) #define set_mb(var, value) do { (void) xchg(&var, value); } while (0) #define set_wmb(var, value) do { var = value; wmb(); } while (0) #define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0) /* interrupt control.. */ #define local_save_flags(x) do { warn_if_not_ulong(x); __asm__ __volatile__("# save_flags \n\t pushfq ; popq %q0":"=g" (x): /* no input */ :"memory"); } while (0) #define local_irq_restore(x) __asm__ __volatile__("# restore_flags \n\t pushq %0 ; popfq": /* no output */ :"g" (x):"memory", "cc") #ifdef CONFIG_X86_VSMP /* Interrupt control for VSMP architecture */ #define local_irq_disable() do { unsigned long flags; local_save_flags(flags); local_irq_restore((flags & ~(1 << 9)) | (1 << 18)); } while (0) #define local_irq_enable() do { unsigned long flags; local_save_flags(flags); local_irq_restore((flags | (1 << 9)) & ~(1 << 18)); } while (0) #define irqs_disabled() \ ({ \ unsigned long flags; \ local_save_flags(flags); \ (flags & (1<<18)) || !(flags & (1<<9)); \ }) /* For spinlocks etc */ #define local_irq_save(x) do { local_save_flags(x); local_irq_restore((x & ~(1 << 9)) | (1 << 18)); } while (0) #else /* CONFIG_X86_VSMP */ #define local_irq_disable() __asm__ __volatile__("cli": : :"memory") #define local_irq_enable() __asm__ __volatile__("sti": : :"memory") #define irqs_disabled() \ ({ \ unsigned long flags; \ local_save_flags(flags); \ !(flags & (1<<9)); \ }) /* For spinlocks etc */ #define local_irq_save(x) do { warn_if_not_ulong(x); __asm__ __volatile__("# local_irq_save \n\t pushfq ; popq %0 ; cli":"=g" (x): /* no input */ :"memory"); } while (0) #endif /* used in the idle loop; sti takes one instruction cycle to complete */ #define safe_halt() __asm__ __volatile__("sti; hlt": : :"memory") /* used when interrupts are already enabled or to shutdown the processor */ #define halt() __asm__ __volatile__("hlt": : :"memory") void cpu_idle_wait(void); extern unsigned long arch_align_stack(unsigned long sp); #endif