52393ccc0a
set_wmb should not be used in the kernel because it just confuses the
code more and has no benefit. Since it is not currently used in the
kernel this patch removes it so that new code does not include it.
All archs define set_wmb(var, value) to do { var = value; wmb(); }
while(0) except ia64 and sparc which use a mb() instead. But this is
still moot since it is not used anyway.
Hasn't been tested on any archs but x86 and x86_64 (and only compiled
tested)
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
254 lines
6.4 KiB
C
254 lines
6.4 KiB
C
#ifndef __ASM_SYSTEM_H
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#define __ASM_SYSTEM_H
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#include <linux/kernel.h>
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#include <asm/segment.h>
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#include <asm/alternative.h>
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#ifdef __KERNEL__
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#define __STR(x) #x
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#define STR(x) __STR(x)
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#define __SAVE(reg,offset) "movq %%" #reg ",(14-" #offset ")*8(%%rsp)\n\t"
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#define __RESTORE(reg,offset) "movq (14-" #offset ")*8(%%rsp),%%" #reg "\n\t"
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/* frame pointer must be last for get_wchan */
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#define SAVE_CONTEXT "pushq %%rbp ; movq %%rsi,%%rbp\n\t"
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#define RESTORE_CONTEXT "movq %%rbp,%%rsi ; popq %%rbp\n\t"
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#define __EXTRA_CLOBBER \
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,"rcx","rbx","rdx","r8","r9","r10","r11","r12","r13","r14","r15"
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#define switch_to(prev,next,last) \
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asm volatile(SAVE_CONTEXT \
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"movq %%rsp,%P[threadrsp](%[prev])\n\t" /* save RSP */ \
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"movq %P[threadrsp](%[next]),%%rsp\n\t" /* restore RSP */ \
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"call __switch_to\n\t" \
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".globl thread_return\n" \
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"thread_return:\n\t" \
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"movq %%gs:%P[pda_pcurrent],%%rsi\n\t" \
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"movq %P[thread_info](%%rsi),%%r8\n\t" \
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LOCK_PREFIX "btr %[tif_fork],%P[ti_flags](%%r8)\n\t" \
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"movq %%rax,%%rdi\n\t" \
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"jc ret_from_fork\n\t" \
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RESTORE_CONTEXT \
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: "=a" (last) \
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: [next] "S" (next), [prev] "D" (prev), \
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[threadrsp] "i" (offsetof(struct task_struct, thread.rsp)), \
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[ti_flags] "i" (offsetof(struct thread_info, flags)),\
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[tif_fork] "i" (TIF_FORK), \
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[thread_info] "i" (offsetof(struct task_struct, thread_info)), \
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[pda_pcurrent] "i" (offsetof(struct x8664_pda, pcurrent)) \
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: "memory", "cc" __EXTRA_CLOBBER)
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extern void load_gs_index(unsigned);
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/*
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* Load a segment. Fall back on loading the zero
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* segment if something goes wrong..
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*/
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#define loadsegment(seg,value) \
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asm volatile("\n" \
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"1:\t" \
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"movl %k0,%%" #seg "\n" \
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"2:\n" \
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".section .fixup,\"ax\"\n" \
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"3:\t" \
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"movl %1,%%" #seg "\n\t" \
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"jmp 2b\n" \
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".previous\n" \
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".section __ex_table,\"a\"\n\t" \
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".align 8\n\t" \
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".quad 1b,3b\n" \
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".previous" \
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: :"r" (value), "r" (0))
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/*
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* Clear and set 'TS' bit respectively
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*/
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#define clts() __asm__ __volatile__ ("clts")
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static inline unsigned long read_cr0(void)
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{
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unsigned long cr0;
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asm volatile("movq %%cr0,%0" : "=r" (cr0));
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return cr0;
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}
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static inline void write_cr0(unsigned long val)
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{
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asm volatile("movq %0,%%cr0" :: "r" (val));
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}
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static inline unsigned long read_cr3(void)
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{
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unsigned long cr3;
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asm("movq %%cr3,%0" : "=r" (cr3));
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return cr3;
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}
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static inline unsigned long read_cr4(void)
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{
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unsigned long cr4;
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asm("movq %%cr4,%0" : "=r" (cr4));
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return cr4;
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}
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static inline void write_cr4(unsigned long val)
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{
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asm volatile("movq %0,%%cr4" :: "r" (val));
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}
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#define stts() write_cr0(8 | read_cr0())
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#define wbinvd() \
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__asm__ __volatile__ ("wbinvd": : :"memory");
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/*
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* On SMP systems, when the scheduler does migration-cost autodetection,
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* it needs a way to flush as much of the CPU's caches as possible.
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*/
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static inline void sched_cacheflush(void)
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{
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wbinvd();
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}
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#endif /* __KERNEL__ */
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#define nop() __asm__ __volatile__ ("nop")
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#define xchg(ptr,v) ((__typeof__(*(ptr)))__xchg((unsigned long)(v),(ptr),sizeof(*(ptr))))
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#define tas(ptr) (xchg((ptr),1))
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#define __xg(x) ((volatile long *)(x))
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static inline void set_64bit(volatile unsigned long *ptr, unsigned long val)
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{
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*ptr = val;
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}
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#define _set_64bit set_64bit
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/*
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* Note: no "lock" prefix even on SMP: xchg always implies lock anyway
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* Note 2: xchg has side effect, so that attribute volatile is necessary,
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* but generally the primitive is invalid, *ptr is output argument. --ANK
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*/
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static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
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{
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switch (size) {
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case 1:
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__asm__ __volatile__("xchgb %b0,%1"
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:"=q" (x)
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:"m" (*__xg(ptr)), "0" (x)
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:"memory");
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break;
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case 2:
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__asm__ __volatile__("xchgw %w0,%1"
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:"=r" (x)
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:"m" (*__xg(ptr)), "0" (x)
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:"memory");
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break;
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case 4:
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__asm__ __volatile__("xchgl %k0,%1"
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:"=r" (x)
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:"m" (*__xg(ptr)), "0" (x)
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:"memory");
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break;
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case 8:
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__asm__ __volatile__("xchgq %0,%1"
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:"=r" (x)
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:"m" (*__xg(ptr)), "0" (x)
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:"memory");
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break;
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}
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return x;
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}
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/*
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* Atomic compare and exchange. Compare OLD with MEM, if identical,
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* store NEW in MEM. Return the initial value in MEM. Success is
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* indicated by comparing RETURN with OLD.
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*/
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#define __HAVE_ARCH_CMPXCHG 1
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static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
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unsigned long new, int size)
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{
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unsigned long prev;
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switch (size) {
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case 1:
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__asm__ __volatile__(LOCK_PREFIX "cmpxchgb %b1,%2"
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: "=a"(prev)
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: "q"(new), "m"(*__xg(ptr)), "0"(old)
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: "memory");
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return prev;
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case 2:
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__asm__ __volatile__(LOCK_PREFIX "cmpxchgw %w1,%2"
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: "=a"(prev)
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: "r"(new), "m"(*__xg(ptr)), "0"(old)
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: "memory");
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return prev;
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case 4:
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__asm__ __volatile__(LOCK_PREFIX "cmpxchgl %k1,%2"
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: "=a"(prev)
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: "r"(new), "m"(*__xg(ptr)), "0"(old)
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: "memory");
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return prev;
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case 8:
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__asm__ __volatile__(LOCK_PREFIX "cmpxchgq %1,%2"
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: "=a"(prev)
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: "r"(new), "m"(*__xg(ptr)), "0"(old)
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: "memory");
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return prev;
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}
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return old;
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}
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#define cmpxchg(ptr,o,n)\
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((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
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(unsigned long)(n),sizeof(*(ptr))))
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#ifdef CONFIG_SMP
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#define smp_mb() mb()
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#define smp_rmb() rmb()
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#define smp_wmb() wmb()
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#define smp_read_barrier_depends() do {} while(0)
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#else
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#define smp_mb() barrier()
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#define smp_rmb() barrier()
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#define smp_wmb() barrier()
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#define smp_read_barrier_depends() do {} while(0)
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#endif
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/*
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* Force strict CPU ordering.
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* And yes, this is required on UP too when we're talking
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* to devices.
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*/
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#define mb() asm volatile("mfence":::"memory")
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#define rmb() asm volatile("lfence":::"memory")
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#ifdef CONFIG_UNORDERED_IO
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#define wmb() asm volatile("sfence" ::: "memory")
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#else
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#define wmb() asm volatile("" ::: "memory")
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#endif
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#define read_barrier_depends() do {} while(0)
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#define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
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#define warn_if_not_ulong(x) do { unsigned long foo; (void) (&(x) == &foo); } while (0)
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#include <linux/irqflags.h>
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void cpu_idle_wait(void);
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extern unsigned long arch_align_stack(unsigned long sp);
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extern void free_init_pages(char *what, unsigned long begin, unsigned long end);
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#endif
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