percpu: fix too lazy vunmap cache flushing

 * @chunk: chunk of interest

 * @page_start: page index of the first page to unmap

 * @page_end: page index of the last page to unmap + 1

 * @flush: whether to flush cache and tlb or not

 * @flush_tlb: whether to flush tlb or not

 *

 * For each cpu, unmap pages [@page_start,@page_end) out of @chunk.

 * If @flush is true, vcache is flushed before unmapping and tlb

 * after.

 */

static void pcpu_unmap(struct pcpu_chunk *chunk, int page_start, int page_end,

		       bool flush)

		       bool flush_tlb)

{

	unsigned int last = num_possible_cpus() - 1;

	unsigned int cpu;

	 * the whole region at once rather than doing it for each cpu.

	 * This could be an overkill but is more scalable.

	 */

	if (flush)

	flush_cache_vunmap(pcpu_chunk_addr(chunk, 0, page_start),

			   pcpu_chunk_addr(chunk, last, page_end));

				(page_end - page_start) << PAGE_SHIFT);

	/* ditto as flush_cache_vunmap() */

	if (flush)

	if (flush_tlb)

		flush_tlb_kernel_range(pcpu_chunk_addr(chunk, 0, page_start),

				       pcpu_chunk_addr(chunk, last, page_end));

}