From: Florian Fainelli <f.fainelli@gmail.com> mainline inclusion from mainline-v5.13-rc1 commit fcf044891c84e38fc90eb736b818781bccf94e38 category: bugfix bugzilla: 106749 https://gitee.com/openeuler/kernel/issues/I4DDEL Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... ----------------------------------------------- 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: Peng Liu <liupeng256@huawei.com> Reviewed-by: tong tiangen <tongtiangen@huawei.com> Signed-off-by: Chen Jun <chenjun102@huawei.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 d54d69cf1732..75f3ab531bdf 100644 --- 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); -- 2.20.1