Linux kernel 笔记 （16）——clflush_cache_range函数

/**
 * clflush_cache_range - flush a cache range with clflush
 * @vaddr:  virtual start address
 * @size:   number of bytes to flush
 *
 * clflushopt is an unordered instruction which needs fencing with mfence or
 * sfence to avoid ordering issues.
 */
void clflush_cache_range(void *vaddr, unsigned int size)
{
    void *vend = vaddr + size - 1;

    mb();

    for (; vaddr < vend; vaddr += boot_cpu_data.x86_clflush_size)
        clflushopt(vaddr);
    /*
     * Flush any possible final partial cacheline:
     */
    clflushopt(vend);

    mb();
}

clflush_cache_range()函数用来把从虚拟地址vaddr起始的，长度为size的的cache line置为无效，各级包含这个cache line的cache系统都会失效。