From: Florian Fainelli f.fainelli@gmail.com
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@gmail.com Signed-off-by: Konrad Rzeszutek Wilk konrad.wilk@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -469,7 +469,11 @@ 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);