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authorChristoph Hellwig2021-06-23 14:21:16 +0200
committerChristoph Hellwig2021-08-18 16:24:09 +0200
commitfaf4ef823ac5f3b6a34a73b76c52895dee3dce55 (patch)
tree81396c9f70e4d8b35b9be650a427c86ff1dc3433
parent2a047e0662aee1bd773e0415accd785ad26a9398 (diff)
dma-direct: add support for dma_coherent_default_memory
Add an option to allocate uncached memory for dma_alloc_coherent from the global dma_coherent_default_memory. This will allow to move arm-nommu (and eventually other platforms) to use generic code for allocating uncached memory from a pre-populated pool. Note that this is a different pool from the one that platforms that can remap at runtime use for GFP_ATOMIC allocations for now, although there might be opportunities to eventually end up with a common codebase for the two use cases. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Dillon Min <dillon.minfei@gmail.com>
-rw-r--r--kernel/dma/Kconfig4
-rw-r--r--kernel/dma/direct.c15
2 files changed, 19 insertions, 0 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 77b405508743..725cfd51762b 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -93,6 +93,10 @@ config DMA_COHERENT_POOL
select GENERIC_ALLOCATOR
bool
+config DMA_GLOBAL_POOL
+ select DMA_DECLARE_COHERENT
+ bool
+
config DMA_REMAP
bool
depends on MMU
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index f33ceb68aef2..8dca4f97d12d 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -156,9 +156,14 @@ void *dma_direct_alloc(struct device *dev, size_t size,
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
!IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
+ !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&
!dev_is_dma_coherent(dev))
return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
+ if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&
+ !dev_is_dma_coherent(dev))
+ return dma_alloc_from_global_coherent(dev, size, dma_handle);
+
/*
* Remapping or decrypting memory may block. If either is required and
* we can't block, allocate the memory from the atomic pools.
@@ -255,11 +260,19 @@ void dma_direct_free(struct device *dev, size_t size,
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
!IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
+ !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&
!dev_is_dma_coherent(dev)) {
arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
return;
}
+ if (IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&
+ !dev_is_dma_coherent(dev)) {
+ if (!dma_release_from_global_coherent(page_order, cpu_addr))
+ WARN_ON_ONCE(1);
+ return;
+ }
+
/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size)))
@@ -462,6 +475,8 @@ int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
+ if (dma_mmap_from_global_coherent(vma, cpu_addr, size, &ret))
+ return ret;
if (vma->vm_pgoff >= count || user_count > count - vma->vm_pgoff)
return -ENXIO;