From: Florian Fainelli <f.fainelli@gmail.com>
To: linux-arm-kernel@lists.infradead.org
Cc: Florian Fainelli <f.fainelli@gmail.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Ard Biesheuvel <ardb@kernel.org>,
Catalin Marinas <catalin.marinas@arm.com>,
open list <linux-kernel@vger.kernel.org>,
Russell King <linux@armlinux.org.uk>,
Max Filippov <jcmvbkbc@gmail.com>,
"open list:SWIOTLB SUBSYSTEM" <iommu@lists.linux-foundation.org>,
opendmb@gmail.com, Andrew Morton <akpm@linux-foundation.org>,
Robin Murphy <robin.murphy@arm.com>,
Christoph Hellwig <hch@lst.de>, Mike Rapoport <rppt@kernel.org>
Subject: [PATCH] ARM: Qualify enabling of swiotlb_init()
Date: Thu, 18 Mar 2021 21:03:33 -0700 [thread overview]
Message-ID: <20210319040333.183827-1-f.fainelli@gmail.com> (raw)
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>
---
arch/arm/mm/init.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
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);
--
2.25.1
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next reply other threads:[~2021-03-19 4:03 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-19 4:03 Florian Fainelli [this message]
2021-03-19 13:07 ` [PATCH] ARM: Qualify enabling of swiotlb_init() Christoph Hellwig
2021-03-19 17:43 ` Florian Fainelli
2021-03-19 19:59 ` Konrad Rzeszutek Wilk
2021-03-20 0:22 ` Stefano Stabellini
2021-03-29 19:30 ` Florian Fainelli
2021-03-30 5:36 ` Christoph Hellwig
2021-04-01 17:33 ` Konrad Rzeszutek Wilk
2021-04-01 19:11 ` Florian Fainelli
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