2 * iommu_fill_pdir - Insert coalesced scatter/gather chunks into the I/O Pdir.
3 * @ioc: The I/O Controller.
4 * @startsg: The scatter/gather list of coalesced chunks.
5 * @nents: The number of entries in the scatter/gather list.
8 * This function inserts the coalesced scatter/gather list chunks into the
9 * I/O Controller's I/O Pdir.
11 static inline unsigned int
12 iommu_fill_pdir(struct ioc *ioc, struct scatterlist *startsg, int nents,
14 void (*iommu_io_pdir_entry)(u64 *, space_t, unsigned long,
17 struct scatterlist *dma_sg = startsg; /* pointer to current DMA */
18 unsigned int n_mappings = 0;
19 unsigned long dma_offset = 0, dma_len = 0;
22 /* Horrible hack. For efficiency's sake, dma_sg starts one
23 * entry below the true start (it is immediately incremented
31 DBG_RUN_SG(" %d : %08lx/%05x %08lx/%05x\n", nents,
32 (unsigned long)sg_dma_address(startsg), cnt,
33 sg_virt_addr(startsg), startsg->length
38 ** Look for the start of a new DMA stream
41 if (sg_dma_address(startsg) & PIDE_FLAG) {
42 u32 pide = sg_dma_address(startsg) & ~PIDE_FLAG;
44 BUG_ON(pdirp && (dma_len != sg_dma_len(dma_sg)));
48 dma_len = sg_dma_len(startsg);
49 sg_dma_len(startsg) = 0;
50 dma_offset = (unsigned long) pide & ~IOVP_MASK;
52 sg_dma_address(dma_sg) = pide;
53 pdirp = &(ioc->pdir_base[pide >> IOVP_SHIFT]);
57 BUG_ON(pdirp == NULL);
59 vaddr = sg_virt_addr(startsg);
60 sg_dma_len(dma_sg) += startsg->length;
61 size = startsg->length + dma_offset;
63 #ifdef IOMMU_MAP_STATS
64 ioc->msg_pages += startsg->length >> IOVP_SHIFT;
67 iommu_io_pdir_entry(pdirp, KERNEL_SPACE,
72 } while(unlikely(size > 0));
80 ** First pass is to walk the SG list and determine where the breaks are
81 ** in the DMA stream. Allocates PDIR entries but does not fill them.
82 ** Returns the number of DMA chunks.
84 ** Doing the fill separate from the coalescing/allocation keeps the
85 ** code simpler. Future enhancement could make one pass through
86 ** the sglist do both.
89 static inline unsigned int
90 iommu_coalesce_chunks(struct ioc *ioc, struct scatterlist *startsg, int nents,
91 int (*iommu_alloc_range)(struct ioc *, size_t))
93 struct scatterlist *contig_sg; /* contig chunk head */
94 unsigned long dma_offset, dma_len; /* start/len of DMA stream */
95 unsigned int n_mappings = 0;
100 ** Prepare for first/next DMA stream
103 dma_len = startsg->length;
104 dma_offset = sg_virt_addr(startsg) & ~IOVP_MASK;
106 /* PARANOID: clear entries */
107 sg_dma_address(startsg) = 0;
108 sg_dma_len(startsg) = 0;
111 ** This loop terminates one iteration "early" since
112 ** it's always looking one "ahead".
115 unsigned long prevstartsg_end, startsg_end;
117 prevstartsg_end = sg_virt_addr(startsg) +
121 startsg_end = sg_virt_addr(startsg) +
124 /* PARANOID: clear entries */
125 sg_dma_address(startsg) = 0;
126 sg_dma_len(startsg) = 0;
129 ** First make sure current dma stream won't
130 ** exceed DMA_CHUNK_SIZE if we coalesce the
133 if(unlikely(ROUNDUP(dma_len + dma_offset + startsg->length,
134 IOVP_SIZE) > DMA_CHUNK_SIZE))
138 ** Next see if we can append the next chunk (i.e.
139 ** it must end on one page and begin on another
141 if (unlikely(((prevstartsg_end | sg_virt_addr(startsg)) & ~PAGE_MASK) != 0))
144 dma_len += startsg->length;
149 ** Terminate last VCONTIG block.
150 ** Allocate space for DMA stream.
152 sg_dma_len(contig_sg) = dma_len;
153 dma_len = ROUNDUP(dma_len + dma_offset, IOVP_SIZE);
154 sg_dma_address(contig_sg) =
156 | (iommu_alloc_range(ioc, dma_len) << IOVP_SHIFT)