Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) 2018-2025, Advanced Micro Devices, Inc. */
3
4#include <linux/mman.h>
5#include <linux/dma-mapping.h>
6
7#include "ionic_fw.h"
8#include "ionic_ibdev.h"
9
10__le64 ionic_pgtbl_dma(struct ionic_tbl_buf *buf, u64 va)
11{
12 u64 pg_mask = BIT_ULL(buf->page_size_log2) - 1;
13 u64 dma;
14
15 if (!buf->tbl_pages)
16 return cpu_to_le64(0);
17
18 if (buf->tbl_pages > 1)
19 return cpu_to_le64(buf->tbl_dma);
20
21 if (buf->tbl_buf)
22 dma = le64_to_cpu(buf->tbl_buf[0]);
23 else
24 dma = buf->tbl_dma;
25
26 return cpu_to_le64(dma + (va & pg_mask));
27}
28
29__be64 ionic_pgtbl_off(struct ionic_tbl_buf *buf, u64 va)
30{
31 if (buf->tbl_pages > 1) {
32 u64 pg_mask = BIT_ULL(buf->page_size_log2) - 1;
33
34 return cpu_to_be64(va & pg_mask);
35 }
36
37 return 0;
38}
39
40int ionic_pgtbl_page(struct ionic_tbl_buf *buf, u64 dma)
41{
42 if (unlikely(buf->tbl_pages == buf->tbl_limit))
43 return -ENOMEM;
44
45 if (buf->tbl_buf)
46 buf->tbl_buf[buf->tbl_pages] = cpu_to_le64(dma);
47 else
48 buf->tbl_dma = dma;
49
50 ++buf->tbl_pages;
51
52 return 0;
53}
54
55static int ionic_tbl_buf_alloc(struct ionic_ibdev *dev,
56 struct ionic_tbl_buf *buf)
57{
58 int rc;
59
60 buf->tbl_size = buf->tbl_limit * sizeof(*buf->tbl_buf);
61 buf->tbl_buf = kmalloc(buf->tbl_size, GFP_KERNEL);
62 if (!buf->tbl_buf)
63 return -ENOMEM;
64
65 buf->tbl_dma = dma_map_single(dev->lif_cfg.hwdev, buf->tbl_buf,
66 buf->tbl_size, DMA_TO_DEVICE);
67 rc = dma_mapping_error(dev->lif_cfg.hwdev, buf->tbl_dma);
68 if (rc) {
69 kfree(buf->tbl_buf);
70 return rc;
71 }
72
73 return 0;
74}
75
76static int ionic_pgtbl_umem(struct ionic_tbl_buf *buf, struct ib_umem *umem)
77{
78 struct ib_block_iter biter;
79 u64 page_dma;
80 int rc;
81
82 rdma_umem_for_each_dma_block(umem, &biter, BIT_ULL(buf->page_size_log2)) {
83 page_dma = rdma_block_iter_dma_address(&biter);
84 rc = ionic_pgtbl_page(buf, page_dma);
85 if (rc)
86 return rc;
87 }
88
89 return 0;
90}
91
92void ionic_pgtbl_unbuf(struct ionic_ibdev *dev, struct ionic_tbl_buf *buf)
93{
94 if (buf->tbl_buf)
95 dma_unmap_single(dev->lif_cfg.hwdev, buf->tbl_dma,
96 buf->tbl_size, DMA_TO_DEVICE);
97
98 kfree(buf->tbl_buf);
99 memset(buf, 0, sizeof(*buf));
100}
101
102int ionic_pgtbl_init(struct ionic_ibdev *dev,
103 struct ionic_tbl_buf *buf,
104 struct ib_umem *umem,
105 dma_addr_t dma,
106 int limit,
107 u64 page_size)
108{
109 int rc;
110
111 memset(buf, 0, sizeof(*buf));
112
113 if (umem) {
114 limit = ib_umem_num_dma_blocks(umem, page_size);
115 buf->page_size_log2 = order_base_2(page_size);
116 }
117
118 if (limit < 1)
119 return -EINVAL;
120
121 buf->tbl_limit = limit;
122
123 /* skip pgtbl if contiguous / direct translation */
124 if (limit > 1) {
125 rc = ionic_tbl_buf_alloc(dev, buf);
126 if (rc)
127 return rc;
128 }
129
130 if (umem)
131 rc = ionic_pgtbl_umem(buf, umem);
132 else
133 rc = ionic_pgtbl_page(buf, dma);
134
135 if (rc)
136 goto err_unbuf;
137
138 return 0;
139
140err_unbuf:
141 ionic_pgtbl_unbuf(dev, buf);
142 return rc;
143}