From fe7514b149e0a8a6f3031d286e52d40163b0b11a Mon Sep 17 00:00:00 2001 From: Alexander Lobakin Date: Tue, 7 May 2024 13:20:20 +0200 Subject: dma: compile-out DMA sync op calls when not used Some platforms do have DMA, but DMA there is always direct and coherent. Currently, even on such platforms DMA sync operations are compiled and called. Add a new hidden Kconfig symbol, DMA_NEED_SYNC, and set it only when either sync operations are needed or there is DMA ops or swiotlb or DMA debug is enabled. Compile global dma_sync_*() and dma_need_sync() only when it's set, otherwise provide empty inline stubs. The change allows for future optimizations of DMA sync calls depending on runtime conditions. Signed-off-by: Alexander Lobakin Signed-off-by: Christoph Hellwig --- kernel/dma/Kconfig | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel/dma/Kconfig') diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig index d62f5957f36b..c06e56be0ca1 100644 --- a/kernel/dma/Kconfig +++ b/kernel/dma/Kconfig @@ -107,6 +107,11 @@ config DMA_BOUNCE_UNALIGNED_KMALLOC bool depends on SWIOTLB +config DMA_NEED_SYNC + def_bool ARCH_HAS_SYNC_DMA_FOR_DEVICE || ARCH_HAS_SYNC_DMA_FOR_CPU || \ + ARCH_HAS_SYNC_DMA_FOR_CPU_ALL || DMA_API_DEBUG || DMA_OPS || \ + SWIOTLB + config DMA_RESTRICTED_POOL bool "DMA Restricted Pool" depends on OF && OF_RESERVED_MEM && SWIOTLB -- cgit v1.2.3