This is a note to let you know that I've just added the patch titled
ARM: Qualify enabling of swiotlb_init()
to the 5.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm-qualify-enabling-of-swiotlb_init.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From fcf044891c84e38fc90eb736b818781bccf94e38 Mon Sep 17 00:00:00 2001
From: Florian Fainelli <f.fainelli@xxxxxxxxx>
Date: Thu, 18 Mar 2021 21:03:33 -0700
Subject: ARM: Qualify enabling of swiotlb_init()
From: Florian Fainelli <f.fainelli@xxxxxxxxx>
commit fcf044891c84e38fc90eb736b818781bccf94e38 upstream.
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@xxxxxxxxx>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm/mm/init.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -378,7 +378,11 @@ 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);
Patches currently in stable-queue which might be from f.fainelli@xxxxxxxxx are
queue-5.10/arm-qualify-enabling-of-swiotlb_init.patch
