LCOV - code coverage report
Current view: top level - klever-core-work-dir/b62ffab/linux-drivers-clk2/lkbce/include/linux - prefetch.h (source / functions) Hit Total Coverage
Test: coverage.info Lines: 1 1 100.0 %
Date: 2017-01-25 Functions: 0 0 -

          Line data    Source code
       1             : /*
       2             :  *  Generic cache management functions. Everything is arch-specific,  
       3             :  *  but this header exists to make sure the defines/functions can be
       4             :  *  used in a generic way.
       5             :  *
       6             :  *  2000-11-13  Arjan van de Ven   <arjan@fenrus.demon.nl>
       7             :  *
       8             :  */
       9             : 
      10             : #ifndef _LINUX_PREFETCH_H
      11             : #define _LINUX_PREFETCH_H
      12             : 
      13             : #include <linux/types.h>
      14             : #include <asm/processor.h>
      15             : #include <asm/cache.h>
      16             : 
      17             : /*
      18             :         prefetch(x) attempts to pre-emptively get the memory pointed to
      19             :         by address "x" into the CPU L1 cache. 
      20             :         prefetch(x) should not cause any kind of exception, prefetch(0) is
      21             :         specifically ok.
      22             : 
      23             :         prefetch() should be defined by the architecture, if not, the 
      24             :         #define below provides a no-op define.  
      25             :         
      26             :         There are 3 prefetch() macros:
      27             :         
      28             :         prefetch(x)     - prefetches the cacheline at "x" for read
      29             :         prefetchw(x)    - prefetches the cacheline at "x" for write
      30             :         spin_lock_prefetch(x) - prefetches the spinlock *x for taking
      31             :         
      32             :         there is also PREFETCH_STRIDE which is the architecure-prefered 
      33             :         "lookahead" size for prefetching streamed operations.
      34             :         
      35             : */
      36             : 
      37             : #ifndef ARCH_HAS_PREFETCH
      38             : #define prefetch(x) __builtin_prefetch(x)
      39             : #endif
      40             : 
      41             : #ifndef ARCH_HAS_PREFETCHW
      42             : #define prefetchw(x) __builtin_prefetch(x,1)
      43             : #endif
      44             : 
      45             : #ifndef ARCH_HAS_SPINLOCK_PREFETCH
      46             : #define spin_lock_prefetch(x) prefetchw(x)
      47             : #endif
      48             : 
      49             : #ifndef PREFETCH_STRIDE
      50             : #define PREFETCH_STRIDE (4*L1_CACHE_BYTES)
      51             : #endif
      52             : 
      53             : static inline void prefetch_range(void *addr, size_t len)
      54             : {
      55             : #ifdef ARCH_HAS_PREFETCH
      56           1 :         char *cp;
      57             :         char *end = addr + len;
      58             : 
      59             :         for (cp = addr; cp < end; cp += PREFETCH_STRIDE)
      60             :                 prefetch(cp);
      61             : #endif
      62             : }
      63             : 
      64             : #endif

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