Commit e2a46567 authored by FUJITA Tomonori's avatar FUJITA Tomonori Committed by Tony Luck
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[IA64] fix SBA IOMMU to handle allocation failure properly 



It's possible that SBA IOMMU might fail to find I/O space under heavy
I/Os.  SBA IOMMU panics on allocation failure but it shouldn't; drivers
can handle the failure.  The majority of other IOMMU drivers don't panic
on allocation failure.

This patch fixes SBA IOMMU path to handle allocation failure properly.

Signed-off-by: default avatarFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarTony Luck <tony.luck@intel.com>
parent 9ee27c76

arch/ia64/hp/common/sba_iommu.c

+29 −9
Original line number Diff line number Diff line
@@ -677,12 +677,19 @@ sba_alloc_range(struct ioc *ioc, struct device *dev, size_t size) 
			spin_unlock_irqrestore(&ioc->saved_lock, flags);



			pide = sba_search_bitmap(ioc, dev, pages_needed, 0);

			if (unlikely(pide >= (ioc->res_size << 3)))

				panic(__FILE__ ": I/O MMU @ %p is out of mapping resources\n",

				      ioc->ioc_hpa);

			if (unlikely(pide >= (ioc->res_size << 3))) {

				printk(KERN_WARNING "%s: I/O MMU @ %p is"

				       "out of mapping resources, %u %u %lx\n",

				       __func__, ioc->ioc_hpa, ioc->res_size,

				       pages_needed, dma_get_seg_boundary(dev));

				return -1;

			}

#else

			panic(__FILE__ ": I/O MMU @ %p is out of mapping resources\n",

			      ioc->ioc_hpa);

			printk(KERN_WARNING "%s: I/O MMU @ %p is"

			       "out of mapping resources, %u %u %lx\n",

			       __func__, ioc->ioc_hpa, ioc->res_size,

			       pages_needed, dma_get_seg_boundary(dev));

			return -1;

#endif

		}

	}
@@ -965,6 +972,8 @@ static dma_addr_t sba_map_page(struct device *dev, struct page *page, 
#endif



	pide = sba_alloc_range(ioc, dev, size);

	if (pide < 0)

		return 0;



	iovp = (dma_addr_t) pide << iovp_shift;
@@ -1320,6 +1329,7 @@ sba_coalesce_chunks(struct ioc *ioc, struct device *dev, 
	unsigned long dma_offset, dma_len; /* start/len of DMA stream */

	int n_mappings = 0;

	unsigned int max_seg_size = dma_get_max_seg_size(dev);

	int idx;



	while (nents > 0) {

		unsigned long vaddr = (unsigned long) sba_sg_address(startsg);
@@ -1418,8 +1428,12 @@ sba_coalesce_chunks(struct ioc *ioc, struct device *dev, 
		vcontig_sg->dma_length = vcontig_len;

		dma_len = (dma_len + dma_offset + ~iovp_mask) & iovp_mask;

		ASSERT(dma_len <= DMA_CHUNK_SIZE);

		dma_sg->dma_address = (dma_addr_t) (PIDE_FLAG

			| (sba_alloc_range(ioc, dev, dma_len) << iovp_shift)

		idx = sba_alloc_range(ioc, dev, dma_len);

		if (idx < 0) {

			dma_sg->dma_length = 0;

			return -1;

		}

		dma_sg->dma_address = (dma_addr_t)(PIDE_FLAG | (idx << iovp_shift)

						   | dma_offset);

		n_mappings++;

	}
@@ -1427,7 +1441,9 @@ sba_coalesce_chunks(struct ioc *ioc, struct device *dev, 
	return n_mappings;

}





static void sba_unmap_sg_attrs(struct device *dev, struct scatterlist *sglist,

			       int nents, enum dma_data_direction dir,

			       struct dma_attrs *attrs);

/**

 * sba_map_sg - map Scatter/Gather list

 * @dev: instance of PCI owned by the driver that's asking.
@@ -1493,6 +1509,10 @@ static int sba_map_sg_attrs(struct device *dev, struct scatterlist *sglist, 
	** Access to the virtual address is what forces a two pass algorithm.

	*/

	coalesced = sba_coalesce_chunks(ioc, dev, sglist, nents);

	if (coalesced < 0) {

		sba_unmap_sg_attrs(dev, sglist, nents, dir, attrs);

		return 0;

	}



	/*

	** Program the I/O Pdir