Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7d21ee4c authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-direct: refine dma_direct_alloc zone selection 



We need to take the DMA offset and encryption bit into account when
selecting a zone.  User the opportunity to factor out the zone
selection into a helper for reuse.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
parent a20bb058

kernel/dma/direct.c

+21 −10
Original line number Diff line number Diff line
@@ -69,6 +69,22 @@ u64 dma_direct_get_required_mask(struct device *dev) 
	return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;

}



static gfp_t __dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,

		u64 *phys_mask)

{

	if (force_dma_unencrypted())

		*phys_mask = __dma_to_phys(dev, dma_mask);

	else

		*phys_mask = dma_to_phys(dev, dma_mask);



	/* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */

	if (*phys_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))

		return GFP_DMA;

	if (*phys_mask <= DMA_BIT_MASK(32))

		return GFP_DMA32;

	return 0;

}



static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)

{

	return phys_to_dma_direct(dev, phys) + size - 1 <=
@@ -81,17 +97,13 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, 
	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;

	int page_order = get_order(size);

	struct page *page = NULL;

	u64 phys_mask;

	void *ret;



	/* we always manually zero the memory once we are done: */

	gfp &= ~__GFP_ZERO;



	/* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */

	if (dev->coherent_dma_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))

		gfp |= GFP_DMA;

	if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))

		gfp |= GFP_DMA32;



	gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,

			&phys_mask);

again:

	/* CMA can be used only in the context which permits sleeping */

	if (gfpflags_allow_blocking(gfp)) {
@@ -110,15 +122,14 @@ void *dma_direct_alloc_pages(struct device *dev, size_t size, 
		page = NULL;



		if (IS_ENABLED(CONFIG_ZONE_DMA32) &&

		    dev->coherent_dma_mask < DMA_BIT_MASK(64) &&

		    phys_mask < DMA_BIT_MASK(64) &&

		    !(gfp & (GFP_DMA32 | GFP_DMA))) {

			gfp |= GFP_DMA32;

			goto again;

		}



		if (IS_ENABLED(CONFIG_ZONE_DMA) &&

		    dev->coherent_dma_mask < DMA_BIT_MASK(32) &&

		    !(gfp & GFP_DMA)) {

		    phys_mask < DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) {

			gfp = (gfp & ~GFP_DMA32) | GFP_DMA;

			goto again;

		}