xref: /openbmc/linux/drivers/crypto/hisilicon/sgl.c (revision ecd25094)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2019 HiSilicon Limited. */
3 #include <linux/dma-mapping.h>
4 #include <linux/module.h>
5 #include "./sgl.h"
6 
7 #define HISI_ACC_SGL_SGE_NR_MIN		1
8 #define HISI_ACC_SGL_SGE_NR_MAX		255
9 #define HISI_ACC_SGL_SGE_NR_DEF		10
10 #define HISI_ACC_SGL_NR_MAX		256
11 #define HISI_ACC_SGL_ALIGN_SIZE		64
12 
13 static int acc_sgl_sge_set(const char *val, const struct kernel_param *kp)
14 {
15 	int ret;
16 	u32 n;
17 
18 	if (!val)
19 		return -EINVAL;
20 
21 	ret = kstrtou32(val, 10, &n);
22 	if (ret != 0 || n > HISI_ACC_SGL_SGE_NR_MAX || n == 0)
23 		return -EINVAL;
24 
25 	return param_set_int(val, kp);
26 }
27 
28 static const struct kernel_param_ops acc_sgl_sge_ops = {
29 	.set = acc_sgl_sge_set,
30 	.get = param_get_int,
31 };
32 
33 static u32 acc_sgl_sge_nr = HISI_ACC_SGL_SGE_NR_DEF;
34 module_param_cb(acc_sgl_sge_nr, &acc_sgl_sge_ops, &acc_sgl_sge_nr, 0444);
35 MODULE_PARM_DESC(acc_sgl_sge_nr, "Number of sge in sgl(1-255)");
36 
37 struct acc_hw_sge {
38 	dma_addr_t buf;
39 	void *page_ctrl;
40 	__le32 len;
41 	__le32 pad;
42 	__le32 pad0;
43 	__le32 pad1;
44 };
45 
46 /* use default sgl head size 64B */
47 struct hisi_acc_hw_sgl {
48 	dma_addr_t next_dma;
49 	__le16 entry_sum_in_chain;
50 	__le16 entry_sum_in_sgl;
51 	__le16 entry_length_in_sgl;
52 	__le16 pad0;
53 	__le64 pad1[5];
54 	struct hisi_acc_hw_sgl *next;
55 	struct acc_hw_sge sge_entries[];
56 } __aligned(1);
57 
58 /**
59  * hisi_acc_create_sgl_pool() - Create a hw sgl pool.
60  * @dev: The device which hw sgl pool belongs to.
61  * @pool: Pointer of pool.
62  * @count: Count of hisi_acc_hw_sgl in pool.
63  *
64  * This function creates a hw sgl pool, after this user can get hw sgl memory
65  * from it.
66  */
67 int hisi_acc_create_sgl_pool(struct device *dev,
68 			     struct hisi_acc_sgl_pool *pool, u32 count)
69 {
70 	u32 sgl_size;
71 	u32 size;
72 
73 	if (!dev || !pool || !count)
74 		return -EINVAL;
75 
76 	sgl_size = sizeof(struct acc_hw_sge) * acc_sgl_sge_nr +
77 		   sizeof(struct hisi_acc_hw_sgl);
78 	size = sgl_size * count;
79 
80 	pool->sgl = dma_alloc_coherent(dev, size, &pool->sgl_dma, GFP_KERNEL);
81 	if (!pool->sgl)
82 		return -ENOMEM;
83 
84 	pool->size = size;
85 	pool->count = count;
86 	pool->sgl_size = sgl_size;
87 
88 	return 0;
89 }
90 EXPORT_SYMBOL_GPL(hisi_acc_create_sgl_pool);
91 
92 /**
93  * hisi_acc_free_sgl_pool() - Free a hw sgl pool.
94  * @dev: The device which hw sgl pool belongs to.
95  * @pool: Pointer of pool.
96  *
97  * This function frees memory of a hw sgl pool.
98  */
99 void hisi_acc_free_sgl_pool(struct device *dev, struct hisi_acc_sgl_pool *pool)
100 {
101 	dma_free_coherent(dev, pool->size, pool->sgl, pool->sgl_dma);
102 	memset(pool, 0, sizeof(struct hisi_acc_sgl_pool));
103 }
104 EXPORT_SYMBOL_GPL(hisi_acc_free_sgl_pool);
105 
106 struct hisi_acc_hw_sgl *acc_get_sgl(struct hisi_acc_sgl_pool *pool, u32 index,
107 				    dma_addr_t *hw_sgl_dma)
108 {
109 	if (!pool || !hw_sgl_dma || index >= pool->count || !pool->sgl)
110 		return ERR_PTR(-EINVAL);
111 
112 	*hw_sgl_dma = pool->sgl_dma + pool->sgl_size * index;
113 	return (void *)pool->sgl + pool->sgl_size * index;
114 }
115 
116 void acc_put_sgl(struct hisi_acc_sgl_pool *pool, u32 index) {}
117 
118 static void sg_map_to_hw_sg(struct scatterlist *sgl,
119 			    struct acc_hw_sge *hw_sge)
120 {
121 	hw_sge->buf = sgl->dma_address;
122 	hw_sge->len = sgl->dma_length;
123 }
124 
125 static void inc_hw_sgl_sge(struct hisi_acc_hw_sgl *hw_sgl)
126 {
127 	hw_sgl->entry_sum_in_sgl++;
128 }
129 
130 static void update_hw_sgl_sum_sge(struct hisi_acc_hw_sgl *hw_sgl, u16 sum)
131 {
132 	hw_sgl->entry_sum_in_chain = sum;
133 }
134 
135 /**
136  * hisi_acc_sg_buf_map_to_hw_sgl - Map a scatterlist to a hw sgl.
137  * @dev: The device which hw sgl belongs to.
138  * @sgl: Scatterlist which will be mapped to hw sgl.
139  * @pool: Pool which hw sgl memory will be allocated in.
140  * @index: Index of hisi_acc_hw_sgl in pool.
141  * @hw_sgl_dma: The dma address of allocated hw sgl.
142  *
143  * This function builds hw sgl according input sgl, user can use hw_sgl_dma
144  * as src/dst in its BD. Only support single hw sgl currently.
145  */
146 struct hisi_acc_hw_sgl *
147 hisi_acc_sg_buf_map_to_hw_sgl(struct device *dev,
148 			      struct scatterlist *sgl,
149 			      struct hisi_acc_sgl_pool *pool,
150 			      u32 index, dma_addr_t *hw_sgl_dma)
151 {
152 	struct hisi_acc_hw_sgl *curr_hw_sgl;
153 	dma_addr_t curr_sgl_dma = 0;
154 	struct acc_hw_sge *curr_hw_sge;
155 	struct scatterlist *sg;
156 	int sg_n = sg_nents(sgl);
157 	int i, ret;
158 
159 	if (!dev || !sgl || !pool || !hw_sgl_dma || sg_n > acc_sgl_sge_nr)
160 		return ERR_PTR(-EINVAL);
161 
162 	ret = dma_map_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
163 	if (!ret)
164 		return ERR_PTR(-EINVAL);
165 
166 	curr_hw_sgl = acc_get_sgl(pool, index, &curr_sgl_dma);
167 	if (!curr_hw_sgl) {
168 		ret = -ENOMEM;
169 		goto err_unmap_sg;
170 	}
171 	curr_hw_sgl->entry_length_in_sgl = acc_sgl_sge_nr;
172 	curr_hw_sge = curr_hw_sgl->sge_entries;
173 
174 	for_each_sg(sgl, sg, sg_n, i) {
175 		sg_map_to_hw_sg(sg, curr_hw_sge);
176 		inc_hw_sgl_sge(curr_hw_sgl);
177 		curr_hw_sge++;
178 	}
179 
180 	update_hw_sgl_sum_sge(curr_hw_sgl, acc_sgl_sge_nr);
181 	*hw_sgl_dma = curr_sgl_dma;
182 
183 	return curr_hw_sgl;
184 
185 err_unmap_sg:
186 	dma_unmap_sg(dev, sgl, sg_n, DMA_BIDIRECTIONAL);
187 	return ERR_PTR(ret);
188 }
189 EXPORT_SYMBOL_GPL(hisi_acc_sg_buf_map_to_hw_sgl);
190 
191 /**
192  * hisi_acc_sg_buf_unmap() - Unmap allocated hw sgl.
193  * @dev: The device which hw sgl belongs to.
194  * @sgl: Related scatterlist.
195  * @hw_sgl: Virtual address of hw sgl.
196  * @hw_sgl_dma: DMA address of hw sgl.
197  * @pool: Pool which hw sgl is allocated in.
198  *
199  * This function unmaps allocated hw sgl.
200  */
201 void hisi_acc_sg_buf_unmap(struct device *dev, struct scatterlist *sgl,
202 			   struct hisi_acc_hw_sgl *hw_sgl)
203 {
204 	dma_unmap_sg(dev, sgl, sg_nents(sgl), DMA_BIDIRECTIONAL);
205 
206 	hw_sgl->entry_sum_in_chain = 0;
207 	hw_sgl->entry_sum_in_sgl = 0;
208 	hw_sgl->entry_length_in_sgl = 0;
209 }
210 EXPORT_SYMBOL_GPL(hisi_acc_sg_buf_unmap);
211 
212 MODULE_LICENSE("GPL v2");
213 MODULE_AUTHOR("Zhou Wang <wangzhou1@hisilicon.com>");
214 MODULE_DESCRIPTION("HiSilicon Accelerator SGL support");
215