Commit 7daa411b authored by Olof Johansson's avatar Olof Johansson Committed by Paul Mackerras
Browse files

[PATCH] powerpc: IOMMU support for honoring dma_mask 



Some devices don't support full 32-bit DMA address space, which we currently
assume. Add the required mask-passing to the IOMMU allocators.

Signed-off-by: default avatarOlof Johansson <olof@lixom.net>
Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
parent f4ffaa45

arch/powerpc/kernel/iommu.c

+26 −10
Original line number Diff line number Diff line
@@ -61,6 +61,7 @@ __setup("iommu=", setup_iommu); 
static unsigned long iommu_range_alloc(struct iommu_table *tbl,

                                       unsigned long npages,

                                       unsigned long *handle,

                                       unsigned long mask,

                                       unsigned int align_order)

{ 

	unsigned long n, end, i, start;
@@ -100,6 +101,18 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl, 


 again:



	if (limit + tbl->it_offset > mask) {

		limit = mask - tbl->it_offset + 1;

		/* If we're constrained on address range, first try

		 * at the masked hint to avoid O(n) search complexity,

		 * but on second pass, start at 0.

		 */

		if ((start & mask) >= limit || pass > 0)

			start = 0;

		else

			start &= mask;

	}



	n = find_next_zero_bit(tbl->it_map, limit, start);



	/* Align allocation */
@@ -150,14 +163,14 @@ static unsigned long iommu_range_alloc(struct iommu_table *tbl, 


static dma_addr_t iommu_alloc(struct iommu_table *tbl, void *page,

		       unsigned int npages, enum dma_data_direction direction,

		       unsigned int align_order)

		       unsigned long mask, unsigned int align_order)

{

	unsigned long entry, flags;

	dma_addr_t ret = DMA_ERROR_CODE;



	spin_lock_irqsave(&(tbl->it_lock), flags);



	entry = iommu_range_alloc(tbl, npages, NULL, align_order);

	entry = iommu_range_alloc(tbl, npages, NULL, mask, align_order);



	if (unlikely(entry == DMA_ERROR_CODE)) {

		spin_unlock_irqrestore(&(tbl->it_lock), flags);
@@ -236,7 +249,7 @@ static void iommu_free(struct iommu_table *tbl, dma_addr_t dma_addr, 


int iommu_map_sg(struct device *dev, struct iommu_table *tbl,

		struct scatterlist *sglist, int nelems,

		enum dma_data_direction direction)

		unsigned long mask, enum dma_data_direction direction)

{

	dma_addr_t dma_next = 0, dma_addr;

	unsigned long flags;
@@ -274,7 +287,7 @@ int iommu_map_sg(struct device *dev, struct iommu_table *tbl, 
		vaddr = (unsigned long)page_address(s->page) + s->offset;

		npages = PAGE_ALIGN(vaddr + slen) - (vaddr & PAGE_MASK);

		npages >>= PAGE_SHIFT;

		entry = iommu_range_alloc(tbl, npages, &handle, 0);

		entry = iommu_range_alloc(tbl, npages, &handle, mask >> PAGE_SHIFT, 0);



		DBG("  - vaddr: %lx, size: %lx\n", vaddr, slen);
@@ -479,7 +492,8 @@ void iommu_free_table(struct device_node *dn) 
 * byte within the page as vaddr.

 */

dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,

		size_t size, enum dma_data_direction direction)

		size_t size, unsigned long mask,

		enum dma_data_direction direction)

{

	dma_addr_t dma_handle = DMA_ERROR_CODE;

	unsigned long uaddr;
@@ -492,7 +506,8 @@ dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr, 
	npages >>= PAGE_SHIFT;



	if (tbl) {

		dma_handle = iommu_alloc(tbl, vaddr, npages, direction, 0);

		dma_handle = iommu_alloc(tbl, vaddr, npages, direction,

					 mask >> PAGE_SHIFT, 0);

		if (dma_handle == DMA_ERROR_CODE) {

			if (printk_ratelimit())  {

				printk(KERN_INFO "iommu_alloc failed, "
@@ -521,7 +536,7 @@ void iommu_unmap_single(struct iommu_table *tbl, dma_addr_t dma_handle, 
 * to the dma address (mapping) of the first page.

 */

void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size,

		dma_addr_t *dma_handle, gfp_t flag)

		dma_addr_t *dma_handle, unsigned long mask, gfp_t flag)

{

	void *ret = NULL;

	dma_addr_t mapping;
@@ -551,7 +566,8 @@ void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size, 
	memset(ret, 0, size);



	/* Set up tces to cover the allocated range */

	mapping = iommu_alloc(tbl, ret, npages, DMA_BIDIRECTIONAL, order);

	mapping = iommu_alloc(tbl, ret, npages, DMA_BIDIRECTIONAL,

			      mask >> PAGE_SHIFT, order);

	if (mapping == DMA_ERROR_CODE) {

		free_pages((unsigned long)ret, order);

		ret = NULL;

arch/powerpc/kernel/pci_iommu.c

+36 −4
Original line number Diff line number Diff line
@@ -59,6 +59,25 @@ static inline struct iommu_table *devnode_table(struct device *dev) 
}





static inline unsigned long device_to_mask(struct device *hwdev)

{

	struct pci_dev *pdev;



	if (!hwdev) {

		pdev = ppc64_isabridge_dev;

		if (!pdev) /* This is the best guess we can do */

			return 0xfffffffful;

	} else

		pdev = to_pci_dev(hwdev);



	if (pdev->dma_mask)

		return pdev->dma_mask;



	/* Assume devices without mask can take 32 bit addresses */

	return 0xfffffffful;

}





/* Allocates a contiguous real buffer and creates mappings over it.

 * Returns the virtual address of the buffer and sets dma_handle

 * to the dma address (mapping) of the first page.
@@ -67,7 +86,7 @@ static void *pci_iommu_alloc_coherent(struct device *hwdev, size_t size, 
			   dma_addr_t *dma_handle, gfp_t flag)

{

	return iommu_alloc_coherent(devnode_table(hwdev), size, dma_handle,

			flag);

			device_to_mask(hwdev), flag);

}



static void pci_iommu_free_coherent(struct device *hwdev, size_t size,
@@ -85,7 +104,8 @@ static void pci_iommu_free_coherent(struct device *hwdev, size_t size, 
static dma_addr_t pci_iommu_map_single(struct device *hwdev, void *vaddr,

		size_t size, enum dma_data_direction direction)

{

	return iommu_map_single(devnode_table(hwdev), vaddr, size, direction);

	return iommu_map_single(devnode_table(hwdev), vaddr, size,

			        device_to_mask(hwdev), direction);

}
@@ -100,7 +120,7 @@ static int pci_iommu_map_sg(struct device *pdev, struct scatterlist *sglist, 
		int nelems, enum dma_data_direction direction)

{

	return iommu_map_sg(pdev, devnode_table(pdev), sglist,

			nelems, direction);

			nelems, device_to_mask(pdev), direction);

}



static void pci_iommu_unmap_sg(struct device *pdev, struct scatterlist *sglist,
@@ -112,6 +132,18 @@ static void pci_iommu_unmap_sg(struct device *pdev, struct scatterlist *sglist, 
/* We support DMA to/from any memory page via the iommu */

static int pci_iommu_dma_supported(struct device *dev, u64 mask)

{

	struct iommu_table *tbl = devnode_table(dev);



	if (!tbl || tbl->it_offset > mask) {

		printk(KERN_INFO "Warning: IOMMU table offset too big for device mask\n");

		if (tbl)

			printk(KERN_INFO "mask: 0x%08lx, table offset: 0x%08lx\n",

				mask, tbl->it_offset);

		else

			printk(KERN_INFO "mask: 0x%08lx, table unavailable\n",

				mask);

		return 0;

	} else

		return 1;

}

arch/powerpc/kernel/vio.c

+3 −3
Original line number Diff line number Diff line
@@ -202,7 +202,7 @@ static dma_addr_t vio_map_single(struct device *dev, void *vaddr, 
			  size_t size, enum dma_data_direction direction)

{

	return iommu_map_single(to_vio_dev(dev)->iommu_table, vaddr, size,

			direction);

			~0ul, direction);

}



static void vio_unmap_single(struct device *dev, dma_addr_t dma_handle,
@@ -216,7 +216,7 @@ static int vio_map_sg(struct device *dev, struct scatterlist *sglist, 
		int nelems, enum dma_data_direction direction)

{

	return iommu_map_sg(dev, to_vio_dev(dev)->iommu_table, sglist,

			nelems, direction);

			nelems, ~0ul, direction);

}



static void vio_unmap_sg(struct device *dev, struct scatterlist *sglist,
@@ -229,7 +229,7 @@ static void *vio_alloc_coherent(struct device *dev, size_t size, 
			   dma_addr_t *dma_handle, gfp_t flag)

{

	return iommu_alloc_coherent(to_vio_dev(dev)->iommu_table, size,

			dma_handle, flag);

			dma_handle, ~0ul, flag);

}



static void vio_free_coherent(struct device *dev, size_t size,

include/asm-powerpc/iommu.h

+4 −3
Original line number Diff line number Diff line
@@ -70,17 +70,18 @@ extern void iommu_free_table(struct device_node *dn); 
extern struct iommu_table *iommu_init_table(struct iommu_table * tbl);



extern int iommu_map_sg(struct device *dev, struct iommu_table *tbl,

		struct scatterlist *sglist, int nelems,

		struct scatterlist *sglist, int nelems, unsigned long mask,

		enum dma_data_direction direction);

extern void iommu_unmap_sg(struct iommu_table *tbl, struct scatterlist *sglist,

		int nelems, enum dma_data_direction direction);



extern void *iommu_alloc_coherent(struct iommu_table *tbl, size_t size,

		dma_addr_t *dma_handle, gfp_t flag);

		dma_addr_t *dma_handle, unsigned long mask, gfp_t flag);

extern void iommu_free_coherent(struct iommu_table *tbl, size_t size,

		void *vaddr, dma_addr_t dma_handle);

extern dma_addr_t iommu_map_single(struct iommu_table *tbl, void *vaddr,

		size_t size, enum dma_data_direction direction);

		size_t size, unsigned long mask,

		enum dma_data_direction direction);

extern void iommu_unmap_single(struct iommu_table *tbl, dma_addr_t dma_handle,

		size_t size, enum dma_data_direction direction);