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git.proxmox.com Git - mirror_ubuntu-jammy-kernel.git/blob - drivers/parisc/iommu-helpers.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #include <linux/prefetch.h>
5 * iommu_fill_pdir - Insert coalesced scatter/gather chunks into the I/O Pdir.
6 * @ioc: The I/O Controller.
7 * @startsg: The scatter/gather list of coalesced chunks.
8 * @nents: The number of entries in the scatter/gather list.
11 * This function inserts the coalesced scatter/gather list chunks into the
12 * I/O Controller's I/O Pdir.
14 static inline unsigned int
15 iommu_fill_pdir(struct ioc
*ioc
, struct scatterlist
*startsg
, int nents
,
17 void (*iommu_io_pdir_entry
)(u64
*, space_t
, unsigned long,
20 struct scatterlist
*dma_sg
= startsg
; /* pointer to current DMA */
21 unsigned int n_mappings
= 0;
22 unsigned long dma_offset
= 0, dma_len
= 0;
25 /* Horrible hack. For efficiency's sake, dma_sg starts one
26 * entry below the true start (it is immediately incremented
34 DBG_RUN_SG(" %d : %08lx/%05x %p/%05x\n", nents
,
35 (unsigned long)sg_dma_address(startsg
), cnt
,
36 sg_virt(startsg
), startsg
->length
41 ** Look for the start of a new DMA stream
44 if (sg_dma_address(startsg
) & PIDE_FLAG
) {
45 u32 pide
= sg_dma_address(startsg
) & ~PIDE_FLAG
;
47 BUG_ON(pdirp
&& (dma_len
!= sg_dma_len(dma_sg
)));
51 dma_len
= sg_dma_len(startsg
);
52 sg_dma_len(startsg
) = 0;
53 dma_offset
= (unsigned long) pide
& ~IOVP_MASK
;
55 #if defined(ZX1_SUPPORT)
56 /* Pluto IOMMU IO Virt Address is not zero based */
57 sg_dma_address(dma_sg
) = pide
| ioc
->ibase
;
59 /* SBA, ccio, and dino are zero based.
60 * Trying to save a few CPU cycles for most users.
62 sg_dma_address(dma_sg
) = pide
;
64 pdirp
= &(ioc
->pdir_base
[pide
>> IOVP_SHIFT
]);
68 BUG_ON(pdirp
== NULL
);
70 vaddr
= (unsigned long)sg_virt(startsg
);
71 sg_dma_len(dma_sg
) += startsg
->length
;
72 size
= startsg
->length
+ dma_offset
;
74 #ifdef IOMMU_MAP_STATS
75 ioc
->msg_pages
+= startsg
->length
>> IOVP_SHIFT
;
78 iommu_io_pdir_entry(pdirp
, KERNEL_SPACE
,
83 } while(unlikely(size
> 0));
91 ** First pass is to walk the SG list and determine where the breaks are
92 ** in the DMA stream. Allocates PDIR entries but does not fill them.
93 ** Returns the number of DMA chunks.
95 ** Doing the fill separate from the coalescing/allocation keeps the
96 ** code simpler. Future enhancement could make one pass through
97 ** the sglist do both.
100 static inline unsigned int
101 iommu_coalesce_chunks(struct ioc
*ioc
, struct device
*dev
,
102 struct scatterlist
*startsg
, int nents
,
103 int (*iommu_alloc_range
)(struct ioc
*, struct device
*, size_t))
105 struct scatterlist
*contig_sg
; /* contig chunk head */
106 unsigned long dma_offset
, dma_len
; /* start/len of DMA stream */
107 unsigned int n_mappings
= 0;
108 unsigned int max_seg_size
= min(dma_get_max_seg_size(dev
),
109 (unsigned)DMA_CHUNK_SIZE
);
110 unsigned int max_seg_boundary
= dma_get_seg_boundary(dev
) + 1;
111 if (max_seg_boundary
) /* check if the addition above didn't overflow */
112 max_seg_size
= min(max_seg_size
, max_seg_boundary
);
117 ** Prepare for first/next DMA stream
120 dma_len
= startsg
->length
;
121 dma_offset
= startsg
->offset
;
123 /* PARANOID: clear entries */
124 sg_dma_address(startsg
) = 0;
125 sg_dma_len(startsg
) = 0;
128 ** This loop terminates one iteration "early" since
129 ** it's always looking one "ahead".
132 unsigned long prev_end
, sg_start
;
134 prev_end
= (unsigned long)sg_virt(startsg
) +
138 sg_start
= (unsigned long)sg_virt(startsg
);
140 /* PARANOID: clear entries */
141 sg_dma_address(startsg
) = 0;
142 sg_dma_len(startsg
) = 0;
145 ** First make sure current dma stream won't
146 ** exceed max_seg_size if we coalesce the
149 if (unlikely(ALIGN(dma_len
+ dma_offset
+ startsg
->length
, IOVP_SIZE
) >
154 * Next see if we can append the next chunk (i.e.
155 * it must end on one page and begin on another, or
156 * it must start on the same address as the previous
159 if (unlikely((prev_end
!= sg_start
) ||
160 ((prev_end
| sg_start
) & ~PAGE_MASK
)))
163 dma_len
+= startsg
->length
;
168 ** Terminate last VCONTIG block.
169 ** Allocate space for DMA stream.
171 sg_dma_len(contig_sg
) = dma_len
;
172 dma_len
= ALIGN(dma_len
+ dma_offset
, IOVP_SIZE
);
173 sg_dma_address(contig_sg
) =
175 | (iommu_alloc_range(ioc
, dev
, dma_len
) << IOVP_SHIFT
)