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dma-mapping: add a new dma_alloc_pages API

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This API is the equivalent of alloc_pages, except that the returned memory
is guaranteed to be DMA addressable by the passed in device.  The
implementation will also be used to provide a more sensible replacement
for DMA_ATTR_NON_CONSISTENT flag.

Additionally dma_alloc_noncoherent is switched over to use dma_alloc_pages
as its backend.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de> (MIPS part)
This commit is contained in:
Christoph Hellwig
2020-09-01 13:34:33 +02:00
parent 5a84292271
commit efa70f2fdc
23 changed files with 206 additions and 37 deletions
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52
kernel/dma/direct.c
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@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018 Christoph Hellwig.
* Copyright (C) 2018-2020 Christoph Hellwig.
*
* DMA operations that map physical memory directly without using an IOMMU.
*/
@@ -292,6 +292,56 @@ void dma_direct_free(struct device *dev, size_t size,
dma_free_contiguous(dev, dma_direct_to_page(dev, dma_addr), size);
}
struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
{
struct page *page;
void *ret;
if (dma_should_alloc_from_pool(dev, gfp, 0)) {
page = dma_alloc_from_pool(dev, size, &ret, gfp,
dma_coherent_ok);
if (!page)
return NULL;
goto done;
}
page = __dma_direct_alloc_pages(dev, size, gfp);
if (!page)
return NULL;
ret = page_address(page);
if (force_dma_unencrypted(dev)) {
if (set_memory_decrypted((unsigned long)ret,
1 << get_order(size)))
goto out_free_pages;
}
memset(ret, 0, size);
done:
*dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
return page;
out_free_pages:
dma_free_contiguous(dev, page, size);
return NULL;
}
void dma_direct_free_pages(struct device *dev, size_t size,
struct page *page, dma_addr_t dma_addr,
enum dma_data_direction dir)
{
unsigned int page_order = get_order(size);
void *vaddr = page_address(page);
/* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
if (dma_should_free_from_pool(dev, 0) &&
dma_free_from_pool(dev, vaddr, size))
return;
if (force_dma_unencrypted(dev))
set_memory_encrypted((unsigned long)vaddr, 1 << page_order);
dma_free_contiguous(dev, page, size);
}
#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
defined(CONFIG_SWIOTLB)
void dma_direct_sync_sg_for_device(struct device *dev,