4d852ef8c2
Instead of using just one bitmap to keep track of IO virtual addresses (handed out for IOMMU use) introduce an array of bitmaps. This allows us to extend existing mappings when running out of iova space in the initial mapping etc. If there is not enough space in the mapping to service an IO virtual address allocation request, __alloc_iova() tries to extend the mapping -- by allocating another bitmap -- and makes another allocation attempt using the freshly allocated bitmap. This allows arm iommu drivers to start with a decent initial size when an dma_iommu_mapping is created and still to avoid running out of IO virtual addresses for the mapping. Signed-off-by: Andreas Herrmann <andreas.herrmann@calxeda.com> [mszyprow: removed extensions parameter to arm_iommu_create_mapping() function, which will be modified in the next patch anyway, also some debug messages about extending bitmap] Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
41 lines
1006 B
C
41 lines
1006 B
C
#ifndef ASMARM_DMA_IOMMU_H
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#define ASMARM_DMA_IOMMU_H
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#ifdef __KERNEL__
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#include <linux/mm_types.h>
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#include <linux/scatterlist.h>
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#include <linux/dma-debug.h>
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#include <linux/kmemcheck.h>
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#include <linux/kref.h>
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struct dma_iommu_mapping {
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/* iommu specific data */
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struct iommu_domain *domain;
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unsigned long **bitmaps; /* array of bitmaps */
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unsigned int nr_bitmaps; /* nr of elements in array */
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unsigned int extensions;
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size_t bitmap_size; /* size of a single bitmap */
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size_t bits; /* per bitmap */
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unsigned int size; /* per bitmap */
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unsigned int order;
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dma_addr_t base;
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spinlock_t lock;
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struct kref kref;
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};
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struct dma_iommu_mapping *
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arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
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int order);
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void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping);
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int arm_iommu_attach_device(struct device *dev,
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struct dma_iommu_mapping *mapping);
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void arm_iommu_detach_device(struct device *dev);
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#endif /* __KERNEL__ */
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#endif
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