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authorChristoph Hellwig <hch@lst.de>2018-11-04 17:27:56 +0100
committerChristoph Hellwig <hch@lst.de>2018-12-01 17:55:02 +0100
commitb18814e767a445534ab9ccba02e82a31208f85d6 (patch)
tree7311d387b5e13abe09b3c9247d007c4efffc881e /kernel/dma
parentc9d76d0655c06b8c1f944e46c4fd9e9cf4b331c0 (diff)
downloadlinux-b18814e767a445534ab9ccba02e82a31208f85d6.tar.bz2
dma-direct: provide page based alloc/free helpers
Some architectures support remapping highmem into DMA coherent allocations. To use the common code for them we need variants of dma_direct_{alloc,free}_pages that do not use kernel virtual addresses. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Diffstat (limited to 'kernel/dma')
-rw-r--r--kernel/dma/direct.c32
1 files changed, 22 insertions, 10 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 22a12ab5a5e9..680287779b0a 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -103,14 +103,13 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
min_not_zero(dev->coherent_dma_mask, dev->bus_dma_mask);
}
-void *dma_direct_alloc_pages(struct device *dev, size_t size,
+struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
int page_order = get_order(size);
struct page *page = NULL;
u64 phys_mask;
- void *ret;
if (attrs & DMA_ATTR_NO_WARN)
gfp |= __GFP_NOWARN;
@@ -150,11 +149,22 @@ again:
}
}
+ return page;
+}
+
+void *dma_direct_alloc_pages(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+{
+ struct page *page;
+ void *ret;
+
+ page = __dma_direct_alloc_pages(dev, size, dma_handle, gfp, attrs);
if (!page)
return NULL;
+
ret = page_address(page);
if (force_dma_unencrypted()) {
- set_memory_decrypted((unsigned long)ret, 1 << page_order);
+ set_memory_decrypted((unsigned long)ret, 1 << get_order(size));
*dma_handle = __phys_to_dma(dev, page_to_phys(page));
} else {
*dma_handle = phys_to_dma(dev, page_to_phys(page));
@@ -163,20 +173,22 @@ again:
return ret;
}
-/*
- * NOTE: this function must never look at the dma_addr argument, because we want
- * to be able to use it as a helper for iommu implementations as well.
- */
+void __dma_direct_free_pages(struct device *dev, size_t size, struct page *page)
+{
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+ if (!dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, get_order(size));
+}
+
void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t dma_addr, unsigned long attrs)
{
- unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned int page_order = get_order(size);
if (force_dma_unencrypted())
set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
- if (!dma_release_from_contiguous(dev, virt_to_page(cpu_addr), count))
- free_pages((unsigned long)cpu_addr, page_order);
+ __dma_direct_free_pages(dev, size, virt_to_page(cpu_addr));
}
void *dma_direct_alloc(struct device *dev, size_t size,