Commit 44335487 authored by Chao Gao's avatar Chao Gao Committed by Christoph Hellwig
Browse files

swiotlb: consolidate rounding up default_nslabs 



default_nslabs are rounded up in two cases with exactly same comments.
Add a simple wrapper to reduce duplicate code/comments. It is preparatory
to adding more logics into the round-up.

No functional change intended.

Signed-off-by: default avatarChao Gao <chao.gao@intel.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 91561d4e

kernel/dma/swiotlb.c

+16 −17
Original line number Diff line number Diff line
@@ -88,6 +88,20 @@ struct io_tlb_area { 
	spinlock_t lock;

};



/*

 * Round up number of slabs to the next power of 2. The last area is going

 * be smaller than the rest if default_nslabs is not power of two.

 *

 * Return true if default_nslabs is rounded up.

 */

static bool round_up_default_nslabs(void)

{

	if (!default_nareas || is_power_of_2(default_nslabs))

		return false;

	default_nslabs = roundup_pow_of_two(default_nslabs);

	return true;

}



static void swiotlb_adjust_nareas(unsigned int nareas)

{

	if (!is_power_of_2(nareas))
@@ -96,17 +110,10 @@ static void swiotlb_adjust_nareas(unsigned int nareas) 
	default_nareas = nareas;



	pr_info("area num %d.\n", nareas);

	/*

	 * Round up number of slabs to the next power of 2.

	 * The last area is going be smaller than the rest if

	 * default_nslabs is not power of two.

	 */

	if (nareas && !is_power_of_2(default_nslabs)) {

		default_nslabs = roundup_pow_of_two(default_nslabs);

	if (round_up_default_nslabs())

		pr_info("SWIOTLB bounce buffer size roundup to %luMB",

			(default_nslabs << IO_TLB_SHIFT) >> 20);

}

}



static int __init

setup_io_tlb_npages(char *str)
@@ -154,18 +161,10 @@ void __init swiotlb_adjust_size(unsigned long size) 
	if (default_nslabs != IO_TLB_DEFAULT_SIZE >> IO_TLB_SHIFT)

		return;



	/*

	 * Round up number of slabs to the next power of 2.

	 * The last area is going be smaller than the rest if

	 * default_nslabs is not power of two.

	 */

	size = ALIGN(size, IO_TLB_SIZE);

	default_nslabs = ALIGN(size >> IO_TLB_SHIFT, IO_TLB_SEGSIZE);

	if (default_nareas) {

		default_nslabs = roundup_pow_of_two(default_nslabs);

	if (round_up_default_nslabs())

		size = default_nslabs << IO_TLB_SHIFT;

	}



	pr_info("SWIOTLB bounce buffer size adjusted to %luMB", size >> 20);

}