Commit 8c18fc63 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'dma-mapping-5.8-6' of git://git.infradead.org/users/hch/dma-mapping into master 

Pull dma-mapping fixes from Christoph Hellwig:
 "Ensure we always have fully addressable memory in the dma coherent
  pool (Nicolas Saenz Julienne)"

* tag 'dma-mapping-5.8-6' of git://git.infradead.org/users/hch/dma-mapping:
  dma-pool: do not allocate pool memory from CMA
  dma-pool: make sure atomic pool suits device
  dma-pool: introduce dma_guess_pool()
  dma-pool: get rid of dma_in_atomic_pool()
  dma-direct: provide function to check physical memory area validity
parents f932d58a d9765e41

include/linux/dma-direct.h

+1 −0
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, 
u64 dma_direct_get_required_mask(struct device *dev);

gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,

				  u64 *phys_mask);

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

void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,

		gfp_t gfp, unsigned long attrs);

void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,

kernel/dma/direct.c

+1 −1
Original line number Diff line number Diff line
@@ -70,7 +70,7 @@ gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask, 
	return 0;

}



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

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

{

	return phys_to_dma_direct(dev, phys) + size - 1 <=

			min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);

kernel/dma/pool.c

+56 −35
Original line number Diff line number Diff line
@@ -6,7 +6,6 @@ 
#include <linux/debugfs.h>

#include <linux/dma-direct.h>

#include <linux/dma-noncoherent.h>

#include <linux/dma-contiguous.h>

#include <linux/init.h>

#include <linux/genalloc.h>

#include <linux/set_memory.h>
@@ -69,11 +68,6 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size, 


	do {

		pool_size = 1 << (PAGE_SHIFT + order);



		if (dev_get_cma_area(NULL))

			page = dma_alloc_from_contiguous(NULL, 1 << order,

							 order, false);

		else

		page = alloc_pages(gfp, order);

	} while (!page && order-- > 0);

	if (!page)
@@ -118,7 +112,6 @@ remove_mapping: 
	dma_common_free_remap(addr, pool_size);

#endif

free_page: __maybe_unused

	if (!dma_release_from_contiguous(NULL, page, 1 << order))

	__free_pages(page, order);

out:

	return ret;
@@ -203,7 +196,7 @@ static int __init dma_atomic_pool_init(void) 
}

postcore_initcall(dma_atomic_pool_init);



static inline struct gen_pool *dev_to_pool(struct device *dev)

static inline struct gen_pool *dma_guess_pool_from_device(struct device *dev)

{

	u64 phys_mask;

	gfp_t gfp;
@@ -217,51 +210,79 @@ static inline struct gen_pool *dev_to_pool(struct device *dev) 
	return atomic_pool_kernel;

}



static bool dma_in_atomic_pool(struct device *dev, void *start, size_t size)

static inline struct gen_pool *dma_get_safer_pool(struct gen_pool *bad_pool)

{

	struct gen_pool *pool = dev_to_pool(dev);

	if (bad_pool == atomic_pool_kernel)

		return atomic_pool_dma32 ? : atomic_pool_dma;



	if (unlikely(!pool))

		return false;

	return gen_pool_has_addr(pool, (unsigned long)start, size);

	if (bad_pool == atomic_pool_dma32)

		return atomic_pool_dma;



	return NULL;

}



static inline struct gen_pool *dma_guess_pool(struct device *dev,

					      struct gen_pool *bad_pool)

{

	if (bad_pool)

		return dma_get_safer_pool(bad_pool);



	return dma_guess_pool_from_device(dev);

}



void *dma_alloc_from_pool(struct device *dev, size_t size,

			  struct page **ret_page, gfp_t flags)

{

	struct gen_pool *pool = dev_to_pool(dev);

	unsigned long val;

	struct gen_pool *pool = NULL;

	unsigned long val = 0;

	void *ptr = NULL;

	phys_addr_t phys;



	while (1) {

		pool = dma_guess_pool(dev, pool);

		if (!pool) {

		WARN(1, "%pGg atomic pool not initialised!\n", &flags);

		return NULL;

			WARN(1, "Failed to get suitable pool for %s\n",

			     dev_name(dev));

			break;

		}



		val = gen_pool_alloc(pool, size);

	if (likely(val)) {

		phys_addr_t phys = gen_pool_virt_to_phys(pool, val);

		if (!val)

			continue;



		phys = gen_pool_virt_to_phys(pool, val);

		if (dma_coherent_ok(dev, phys, size))

			break;



		gen_pool_free(pool, val, size);

		val = 0;

	}





	if (val) {

		*ret_page = pfn_to_page(__phys_to_pfn(phys));

		ptr = (void *)val;

		memset(ptr, 0, size);

	} else {

		WARN_ONCE(1, "DMA coherent pool depleted, increase size "

			     "(recommended min coherent_pool=%zuK)\n",

			  gen_pool_size(pool) >> 9);

	}



		if (gen_pool_avail(pool) < atomic_pool_size)

			schedule_work(&atomic_pool_work);

	}



	return ptr;

}



bool dma_free_from_pool(struct device *dev, void *start, size_t size)

{

	struct gen_pool *pool = dev_to_pool(dev);

	struct gen_pool *pool = NULL;



	if (!dma_in_atomic_pool(dev, start, size))

	while (1) {

		pool = dma_guess_pool(dev, pool);

		if (!pool)

			return false;



		if (gen_pool_has_addr(pool, (unsigned long)start, size)) {

			gen_pool_free(pool, (unsigned long)start, size);

			return true;

		}

	}

}

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