From 442d366cc1aabc699015a2e10a41bba17fe416ad Mon Sep 17 00:00:00 2001 From: Mostafa Saleh Date: Wed, 3 Jun 2026 11:05:20 +0000 Subject: arm64/mm: Simplify SWIOTLB setup in arch_mm_preinit() At the moment, arch_mm_preinit() checks if the system has limited addressing or is running under CCA to enable SWIOTLB, only after to be forced to true anyway if it was false due to CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC being unconditionally true for arm64. Simplify this logic, by making it clear that SWIOTLB is always used but its size depends on the address layout of the system. Signed-off-by: Mostafa Saleh Reviewed-by: Catalin Marinas Reviewed-by: Aneesh Kumar K.V (Arm) Tested-by: Aneesh Kumar K.V (Arm) Signed-off-by: Will Deacon --- arch/arm64/mm/init.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 97987f850a33..9fb17043dd0d 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -336,25 +336,21 @@ void __init arch_setup_zero_pages(void) void __init arch_mm_preinit(void) { unsigned int flags = SWIOTLB_VERBOSE; - bool swiotlb = max_pfn > PFN_DOWN(arm64_dma_phys_limit); if (is_realm_world()) { - swiotlb = true; flags |= SWIOTLB_FORCE; - } - - if (IS_ENABLED(CONFIG_DMA_BOUNCE_UNALIGNED_KMALLOC) && !swiotlb) { + } else if (max_pfn <= PFN_DOWN(arm64_dma_phys_limit)) { /* * If no bouncing needed for ZONE_DMA, reduce the swiotlb * buffer for kmalloc() bouncing to 1MB per 1GB of RAM. */ unsigned long size = DIV_ROUND_UP(memblock_phys_mem_size(), 1024); + swiotlb_adjust_size(min(swiotlb_size_or_default(), size)); - swiotlb = true; } - swiotlb_init(swiotlb, flags); + swiotlb_init(true, flags); /* * Check boundaries twice: Some fundamental inconsistencies can be -- cgit v1.2.3