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authorChristoph Hellwig <hch@lst.de>2019-06-03 08:43:51 +0200
committerChristoph Hellwig <hch@lst.de>2019-06-03 16:00:08 +0200
commitc30700db9eaabb35e0b123301df35a6846e6b6b4 (patch)
tree96e4e6018c0b6e92289aee5093082c6322ab7abf /kernel/dma
parent67f30ad19c4b329dbe47e1563b2017203bd02e34 (diff)
downloadlinux-c30700db9eaabb35e0b123301df35a6846e6b6b4.tar.bz2
dma-direct: provide generic support for uncached kernel segments
A few architectures support uncached kernel segments. In that case we get an uncached mapping for a given physica address by using an offset in the uncached segement. Implement support for this scheme in the generic dma-direct code instead of duplicating it in arch hooks. Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/direct.c17
1 files changed, 15 insertions, 2 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 0816c1e8b05a..b67f0aa08aa3 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -158,6 +158,13 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size,
*dma_handle = phys_to_dma(dev, page_to_phys(page));
}
memset(ret, 0, size);
+
+ if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
+ !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT)) {
+ arch_dma_prep_coherent(page, size);
+ ret = uncached_kernel_address(ret);
+ }
+
return ret;
}
@@ -173,13 +180,18 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
if (force_dma_unencrypted())
set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
+
+ if (IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
+ !dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_NON_CONSISTENT))
+ cpu_addr = cached_kernel_address(cpu_addr);
__dma_direct_free_pages(dev, size, virt_to_page(cpu_addr));
}
void *dma_direct_alloc(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
- if (!dev_is_dma_coherent(dev))
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
+ !dev_is_dma_coherent(dev))
return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
return dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs);
}
@@ -187,7 +199,8 @@ void *dma_direct_alloc(struct device *dev, size_t size,
void dma_direct_free(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs)
{
- if (!dev_is_dma_coherent(dev))
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_UNCACHED_SEGMENT) &&
+ !dev_is_dma_coherent(dev))
arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
else
dma_direct_free_pages(dev, size, cpu_addr, dma_addr, attrs);