Commit 803c874a authored by Chris Metcalf's avatar Chris Metcalf
Browse files

tile: support LSI MEGARAID SAS HBA hybrid dma_ops 



The LSI MEGARAID SAS HBA suffers from the problem where it can do
64-bit DMA to streaming buffers but not to consistent buffers.
In other words, 64-bit DMA is used for disk data transfers and 32-bit
DMA must be used for control message transfers. According to LSI,
the firmware is not fully functional yet. This change implements a
kind of hybrid dma_ops to support this.

Note that on most other platforms, the 64-bit DMA addressing space is the
same as the 32-bit DMA space and they overlap the physical memory space.
No special arrangement is needed to support this kind of mixed DMA
capability.  On TILE-Gx, the 64-bit DMA space is completely separate
from the 32-bit DMA space.  Due to the use of the IOMMU, the 64-bit DMA
space doesn't overlap the physical memory space.  On the other hand,
the 32-bit DMA space overlaps the physical memory space under 4GB.
The separate address spaces make it necessary to have separate dma_ops.

Signed-off-by: default avatarChris Metcalf <cmetcalf@tilera.com>
parent 26cde05a

arch/tile/include/asm/dma-mapping.h

+7 −3
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
extern struct dma_map_ops *tile_dma_map_ops;

extern struct dma_map_ops *gx_pci_dma_map_ops;

extern struct dma_map_ops *gx_legacy_pci_dma_map_ops;

extern struct dma_map_ops *gx_hybrid_pci_dma_map_ops;



static inline struct dma_map_ops *get_dma_ops(struct device *dev)

{
@@ -44,12 +45,12 @@ static inline void set_dma_offset(struct device *dev, dma_addr_t off) 


static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)

{

	return paddr + get_dma_offset(dev);

	return paddr;

}



static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)

{

	return daddr - get_dma_offset(dev);

	return daddr;

}



static inline void dma_mark_clean(void *addr, size_t size) {}
@@ -88,7 +89,10 @@ dma_set_mask(struct device *dev, u64 mask) 
	struct dma_map_ops *dma_ops = get_dma_ops(dev);



	/* Handle legacy PCI devices with limited memory addressability. */

	if ((dma_ops == gx_pci_dma_map_ops) && (mask <= DMA_BIT_MASK(32))) {

	if ((dma_ops == gx_pci_dma_map_ops ||

	     dma_ops == gx_hybrid_pci_dma_map_ops ||

	     dma_ops == gx_legacy_pci_dma_map_ops) &&

	    (mask <= DMA_BIT_MASK(32))) {

		set_dma_ops(dev, gx_legacy_pci_dma_map_ops);

		set_dma_offset(dev, 0);

		if (mask > dev->archdata.max_direct_dma_addr)

arch/tile/kernel/pci-dma.c

+31 −9
Original line number Diff line number Diff line
@@ -357,7 +357,7 @@ static void *tile_pci_dma_alloc_coherent(struct device *dev, size_t size, 


	addr = page_to_phys(pg);



	*dma_handle = phys_to_dma(dev, addr);

	*dma_handle = addr + get_dma_offset(dev);



	return page_address(pg);

}
@@ -387,7 +387,7 @@ static int tile_pci_dma_map_sg(struct device *dev, struct scatterlist *sglist, 
		sg->dma_address = sg_phys(sg);

		__dma_prep_pa_range(sg->dma_address, sg->length, direction);



		sg->dma_address = phys_to_dma(dev, sg->dma_address);

		sg->dma_address = sg->dma_address + get_dma_offset(dev);

#ifdef CONFIG_NEED_SG_DMA_LENGTH

		sg->dma_length = sg->length;

#endif
@@ -422,7 +422,7 @@ static dma_addr_t tile_pci_dma_map_page(struct device *dev, struct page *page, 
	BUG_ON(offset + size > PAGE_SIZE);

	__dma_prep_page(page, offset, size, direction);



	return phys_to_dma(dev, page_to_pa(page) + offset);

	return page_to_pa(page) + offset + get_dma_offset(dev);

}



static void tile_pci_dma_unmap_page(struct device *dev, dma_addr_t dma_address,
@@ -432,7 +432,7 @@ static void tile_pci_dma_unmap_page(struct device *dev, dma_addr_t dma_address, 
{

	BUG_ON(!valid_dma_direction(direction));



	dma_address = dma_to_phys(dev, dma_address);

	dma_address -= get_dma_offset(dev);



	__dma_complete_page(pfn_to_page(PFN_DOWN(dma_address)),

			    dma_address & PAGE_OFFSET, size, direction);
@@ -445,7 +445,7 @@ static void tile_pci_dma_sync_single_for_cpu(struct device *dev, 
{

	BUG_ON(!valid_dma_direction(direction));



	dma_handle = dma_to_phys(dev, dma_handle);

	dma_handle -= get_dma_offset(dev);



	__dma_complete_pa_range(dma_handle, size, direction);

}
@@ -456,7 +456,7 @@ static void tile_pci_dma_sync_single_for_device(struct device *dev, 
						enum dma_data_direction

						direction)

{

	dma_handle = dma_to_phys(dev, dma_handle);

	dma_handle -= get_dma_offset(dev);



	__dma_prep_pa_range(dma_handle, size, direction);

}
@@ -558,21 +558,43 @@ static struct dma_map_ops pci_swiotlb_dma_ops = { 
	.mapping_error = swiotlb_dma_mapping_error,

};



static struct dma_map_ops pci_hybrid_dma_ops = {

	.alloc = tile_swiotlb_alloc_coherent,

	.free = tile_swiotlb_free_coherent,

	.map_page = tile_pci_dma_map_page,

	.unmap_page = tile_pci_dma_unmap_page,

	.map_sg = tile_pci_dma_map_sg,

	.unmap_sg = tile_pci_dma_unmap_sg,

	.sync_single_for_cpu = tile_pci_dma_sync_single_for_cpu,

	.sync_single_for_device = tile_pci_dma_sync_single_for_device,

	.sync_sg_for_cpu = tile_pci_dma_sync_sg_for_cpu,

	.sync_sg_for_device = tile_pci_dma_sync_sg_for_device,

	.mapping_error = tile_pci_dma_mapping_error,

	.dma_supported = tile_pci_dma_supported

};



struct dma_map_ops *gx_legacy_pci_dma_map_ops = &pci_swiotlb_dma_ops;

struct dma_map_ops *gx_hybrid_pci_dma_map_ops = &pci_hybrid_dma_ops;

#else

struct dma_map_ops *gx_legacy_pci_dma_map_ops;

struct dma_map_ops *gx_hybrid_pci_dma_map_ops;

#endif

EXPORT_SYMBOL(gx_legacy_pci_dma_map_ops);

EXPORT_SYMBOL(gx_hybrid_pci_dma_map_ops);



#ifdef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK

int dma_set_coherent_mask(struct device *dev, u64 mask)

{

	struct dma_map_ops *dma_ops = get_dma_ops(dev);



	/* Handle legacy PCI devices with limited memory addressability. */

	if (((dma_ops == gx_pci_dma_map_ops) ||

	    (dma_ops == gx_legacy_pci_dma_map_ops)) &&

	/* Handle hybrid PCI devices with limited memory addressability. */

	if ((dma_ops == gx_pci_dma_map_ops ||

	     dma_ops == gx_hybrid_pci_dma_map_ops ||

	     dma_ops == gx_legacy_pci_dma_map_ops) &&

	    (mask <= DMA_BIT_MASK(32))) {

		if (dma_ops == gx_pci_dma_map_ops)

			set_dma_ops(dev, gx_hybrid_pci_dma_map_ops);



		if (mask > dev->archdata.max_direct_dma_addr)

			mask = dev->archdata.max_direct_dma_addr;

	}

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