summary refs log tree commit diff
path: root/arch
diff options
context:
space:
mode:
authorFlorian Fainelli <f.fainelli@gmail.com>2021-03-18 21:03:33 -0700
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2021-03-19 05:00:18 +0000
commitfcf044891c84e38fc90eb736b818781bccf94e38 (patch)
tree4f6af8d4dab1566a3e9b3a64d563e2aad61ef836 /arch
parent2cbc2776efe4faed0e17c48ae076aa03a0fcc61f (diff)
downloadlinux-fcf044891c84e38fc90eb736b818781bccf94e38.tar.gz
ARM: Qualify enabling of swiotlb_init()
We do not need a SWIOTLB unless we have DRAM that is addressable beyond
the arm_dma_limit. Compare max_pfn with arm_dma_pfn_limit to determine
whether we do need a SWIOTLB to be initialized.

Fixes: ad3c7b18c5b3 ("arm: use swiotlb for bounce buffering on LPAE configs")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mm/init.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 828a2561b229..8356bf1daa28 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -301,7 +301,11 @@ static void __init free_highpages(void)
 void __init mem_init(void)
 {
 #ifdef CONFIG_ARM_LPAE
-	swiotlb_init(1);
+	if (swiotlb_force == SWIOTLB_FORCE ||
+	    max_pfn > arm_dma_pfn_limit)
+		swiotlb_init(1);
+	else
+		swiotlb_force = SWIOTLB_NO_FORCE;
 #endif
 
 	set_max_mapnr(pfn_to_page(max_pfn) - mem_map);