From: Chao Gao <chao.gao@intel.com>
Date: Fri, 15 Jul 2022 18:45:34 +0800
Subject: swiotlb: consolidate rounding up default_nslabs
Git-commit: 44335487bab05e06902f9184179857aae764bfe6
Patch-mainline: v6.0-rc1
References: jsc#PED-3259
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 <chao.gao@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Joerg Roedel <jroedel@suse.de>
---
kernel/dma/swiotlb.c | 33 ++++++++++++++++-----------------
1 file changed, 16 insertions(+), 17 deletions(-)
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);
}