diff options
| author | Alexander Lobakin <aleksander.lobakin@intel.com> | 2024-05-07 13:20:20 +0200 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2024-05-07 13:29:53 +0200 |
| commit | fe7514b149e0a8a6f3031d286e52d40163b0b11a (patch) | |
| tree | 6e9bab82f3717433f89e243770d4ad9e559b32a3 /kernel/dma | |
| parent | 2650073f1b5858008c32712f3d9e1e808ce7e967 (diff) | |
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 <aleksander.lobakin@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/Kconfig | 5 | ||||
| -rw-r--r-- | kernel/dma/mapping.c | 22 |
2 files changed, 17 insertions, 10 deletions
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 diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 58db8fd70471..c78b78e95a26 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -329,6 +329,7 @@ void dma_unmap_resource(struct device *dev, dma_addr_t addr, size_t size, } EXPORT_SYMBOL(dma_unmap_resource); +#ifdef CONFIG_DMA_NEED_SYNC void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr, size_t size, enum dma_data_direction dir) { @@ -385,6 +386,17 @@ void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL(dma_sync_sg_for_device); +bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + + if (dma_map_direct(dev, ops)) + return dma_direct_need_sync(dev, dma_addr); + return ops->sync_single_for_cpu || ops->sync_single_for_device; +} +EXPORT_SYMBOL_GPL(dma_need_sync); +#endif /* CONFIG_DMA_NEED_SYNC */ + /* * The whole dma_get_sgtable() idea is fundamentally unsafe - it seems * that the intention is to allow exporting memory allocated via the @@ -841,16 +853,6 @@ size_t dma_opt_mapping_size(struct device *dev) } EXPORT_SYMBOL_GPL(dma_opt_mapping_size); -bool dma_need_sync(struct device *dev, dma_addr_t dma_addr) -{ - const struct dma_map_ops *ops = get_dma_ops(dev); - - if (dma_map_direct(dev, ops)) - return dma_direct_need_sync(dev, dma_addr); - return ops->sync_single_for_cpu || ops->sync_single_for_device; -} -EXPORT_SYMBOL_GPL(dma_need_sync); - unsigned long dma_get_merge_boundary(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); |