Commit 4a47cbae authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-direct: improve swiotlb error reporting 



Untangle the way how dma_direct_map_page calls into swiotlb to be able
to properly report errors where the swiotlb DMA address overflows the
mask separately from overflows in the !swiotlb case.  This means that
siotlb_map now has to do a little more work that duplicates
dma_direct_map_page, but doing so greatly simplifies the calling
convention.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>
parent 91ef26f9

include/linux/swiotlb.h

+3 −8
Original line number Diff line number Diff line
@@ -64,6 +64,9 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev, 
				    size_t size, enum dma_data_direction dir,

				    enum dma_sync_target target);



dma_addr_t swiotlb_map(struct device *dev, phys_addr_t phys,

		size_t size, enum dma_data_direction dir, unsigned long attrs);



#ifdef CONFIG_SWIOTLB

extern enum swiotlb_force swiotlb_force;

extern phys_addr_t io_tlb_start, io_tlb_end;
@@ -73,8 +76,6 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr) 
	return paddr >= io_tlb_start && paddr < io_tlb_end;

}



bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,

		size_t size, enum dma_data_direction dir, unsigned long attrs);

void __init swiotlb_exit(void);

unsigned int swiotlb_max_segment(void);

size_t swiotlb_max_mapping_size(struct device *dev);
@@ -85,12 +86,6 @@ static inline bool is_swiotlb_buffer(phys_addr_t paddr) 
{

	return false;

}

static inline bool swiotlb_map(struct device *dev, phys_addr_t *phys,

		dma_addr_t *dma_addr, size_t size, enum dma_data_direction dir,

		unsigned long attrs)

{

	return false;

}

static inline void swiotlb_exit(void)

{

}

kernel/dma/direct.c

+7 −9
Original line number Diff line number Diff line
@@ -357,13 +357,6 @@ void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl, 
EXPORT_SYMBOL(dma_direct_unmap_sg);

#endif



static inline bool dma_direct_possible(struct device *dev, dma_addr_t dma_addr,

		size_t size)

{

	return swiotlb_force != SWIOTLB_FORCE &&

		dma_capable(dev, dma_addr, size, true);

}



dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,

		unsigned long offset, size_t size, enum dma_data_direction dir,

		unsigned long attrs)
@@ -371,8 +364,13 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, 
	phys_addr_t phys = page_to_phys(page) + offset;

	dma_addr_t dma_addr = phys_to_dma(dev, phys);



	if (unlikely(!dma_direct_possible(dev, dma_addr, size)) &&

	    !swiotlb_map(dev, &phys, &dma_addr, size, dir, attrs)) {

	if (unlikely(swiotlb_force == SWIOTLB_FORCE))

		return swiotlb_map(dev, phys, size, dir, attrs);



	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {

		if (swiotlb_force != SWIOTLB_NO_FORCE)

			return swiotlb_map(dev, phys, size, dir, attrs);



		report_addr(dev, dma_addr, size);

		return DMA_MAPPING_ERROR;

	}

kernel/dma/swiotlb.c

+23 −19
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 


#include <linux/cache.h>

#include <linux/dma-direct.h>

#include <linux/dma-noncoherent.h>

#include <linux/mm.h>

#include <linux/export.h>

#include <linux/spinlock.h>
@@ -656,35 +657,38 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, 
}



/*

 * Create a swiotlb mapping for the buffer at @phys, and in case of DMAing

 * Create a swiotlb mapping for the buffer at @paddr, and in case of DMAing

 * to the device copy the data into it as well.

 */

bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr,

		size_t size, enum dma_data_direction dir, unsigned long attrs)

dma_addr_t swiotlb_map(struct device *dev, phys_addr_t paddr, size_t size,

		enum dma_data_direction dir, unsigned long attrs)

{

	trace_swiotlb_bounced(dev, *dma_addr, size, swiotlb_force);

	phys_addr_t swiotlb_addr;

	dma_addr_t dma_addr;



	if (unlikely(swiotlb_force == SWIOTLB_NO_FORCE)) {

		dev_warn_ratelimited(dev,

			"Cannot do DMA to address %pa\n", phys);

		return false;

	}

	trace_swiotlb_bounced(dev, phys_to_dma(dev, paddr), size,

			      swiotlb_force);



	/* Oh well, have to allocate and map a bounce buffer. */

	*phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start),

			*phys, size, size, dir, attrs);

	if (*phys == (phys_addr_t)DMA_MAPPING_ERROR)

		return false;

	swiotlb_addr = swiotlb_tbl_map_single(dev,

			__phys_to_dma(dev, io_tlb_start),

			paddr, size, size, dir, attrs);

	if (swiotlb_addr == (phys_addr_t)DMA_MAPPING_ERROR)

		return DMA_MAPPING_ERROR;



	/* Ensure that the address returned is DMA'ble */

	*dma_addr = __phys_to_dma(dev, *phys);

	if (unlikely(!dma_capable(dev, *dma_addr, size, true))) {

		swiotlb_tbl_unmap_single(dev, *phys, size, size, dir,

	dma_addr = __phys_to_dma(dev, swiotlb_addr);

	if (unlikely(!dma_capable(dev, dma_addr, size, true))) {

		swiotlb_tbl_unmap_single(dev, swiotlb_addr, size, size, dir,

			attrs | DMA_ATTR_SKIP_CPU_SYNC);

		return false;

		dev_WARN_ONCE(dev, 1,

			"swiotlb addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",

			&dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);

		return DMA_MAPPING_ERROR;

	}



	return true;

	if (!dev_is_dma_coherent(dev) && !(attrs & DMA_ATTR_SKIP_CPU_SYNC))

		arch_sync_dma_for_device(swiotlb_addr, size, dir);

	return dma_addr;

}



size_t swiotlb_max_mapping_size(struct device *dev)

CRA Git | Maintained and supported by SUSTech CRA and CCSE