From 44335487bab05e06902f9184179857aae764bfe6 Mon Sep 17 00:00:00 2001 From: Chao Gao Date: Fri, 15 Jul 2022 18:45:34 +0800 Subject: 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: Chao Gao Signed-off-by: Christoph Hellwig --- kernel/dma/swiotlb.c | 33 ++++++++++++++++----------------- 1 file changed, 16 insertions(+), 17 deletions(-) (limited to 'kernel/dma') diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index cbffa0b1ace5..604f2469ac0e 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -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)) @@ -96,16 +110,9 @@ 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 @@ -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); } -- cgit v1.2.3