From ad96ce3252dbab773cb343220662df3d84dd8e80 Mon Sep 17 00:00:00 2001 From: Petr Tesarik Date: Tue, 1 Aug 2023 08:24:02 +0200 Subject: [PATCH] swiotlb: determine potential physical address limit The value returned by default_swiotlb_limit() should be constant, because it is used to decide whether DMA can be used. To allow allocating memory pools on the fly, use the maximum possible physical address rather than the highest address used by the default pool. For swiotlb_init_remap(), this is either an arch-specific limit used by memblock_alloc_low(), or the highest directly mapped physical address if the initialization flags include SWIOTLB_ANY. For swiotlb_init_late(), the highest address is determined by the GFP flags. Signed-off-by: Petr Tesarik Signed-off-by: Christoph Hellwig --- include/linux/swiotlb.h | 2 ++ kernel/dma/swiotlb.c | 14 ++++++++++++++ 2 files changed, 16 insertions(+) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 66867d2..9825fa1 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -109,6 +109,7 @@ struct io_tlb_pool { * @force_bounce: %true if swiotlb bouncing is forced * @for_alloc: %true if the pool is used for memory allocation * @can_grow: %true if more pools can be allocated dynamically. + * @phys_limit: Maximum allowed physical address. * @total_used: The total number of slots in the pool that are currently used * across all areas. Used only for calculating used_hiwater in * debugfs. @@ -123,6 +124,7 @@ struct io_tlb_mem { bool for_alloc; #ifdef CONFIG_SWIOTLB_DYNAMIC bool can_grow; + u64 phys_limit; #endif #ifdef CONFIG_DEBUG_FS atomic_long_t total_used; diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 30d0fcc..0fa081d 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -334,6 +334,10 @@ void __init swiotlb_init_remap(bool addressing_limit, unsigned int flags, #ifdef CONFIG_SWIOTLB_DYNAMIC if (!remap) io_tlb_default_mem.can_grow = true; + if (flags & SWIOTLB_ANY) + io_tlb_default_mem.phys_limit = virt_to_phys(high_memory - 1); + else + io_tlb_default_mem.phys_limit = ARCH_LOW_ADDRESS_LIMIT; #endif if (!default_nareas) @@ -409,6 +413,12 @@ int swiotlb_init_late(size_t size, gfp_t gfp_mask, #ifdef CONFIG_SWIOTLB_DYNAMIC if (!remap) io_tlb_default_mem.can_grow = true; + if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp_mask & __GFP_DMA)) + io_tlb_default_mem.phys_limit = DMA_BIT_MASK(zone_dma_bits); + else if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp_mask & __GFP_DMA32)) + io_tlb_default_mem.phys_limit = DMA_BIT_MASK(32); + else + io_tlb_default_mem.phys_limit = virt_to_phys(high_memory - 1); #endif if (!default_nareas) @@ -1397,7 +1407,11 @@ phys_addr_t default_swiotlb_base(void) */ phys_addr_t default_swiotlb_limit(void) { +#ifdef CONFIG_SWIOTLB_DYNAMIC + return io_tlb_default_mem.phys_limit; +#else return io_tlb_default_mem.defpool.end - 1; +#endif } #ifdef CONFIG_DEBUG_FS -- 2.7.4