1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /* Copyright (c) 2019 Mellanox Technologies */
3
4 #include <linux/pci.h>
5 #include "mlx5_core.h"
6 #include "pci_vsc.h"
7
8 #define MLX5_EXTRACT_C(source, offset, size) \
9 ((((u32)(source)) >> (offset)) & MLX5_ONES32(size))
10 #define MLX5_EXTRACT(src, start, len) \
11 (((len) == 32) ? (src) : MLX5_EXTRACT_C(src, start, len))
12 #define MLX5_ONES32(size) \
13 ((size) ? (0xffffffff >> (32 - (size))) : 0)
14 #define MLX5_MASK32(offset, size) \
15 (MLX5_ONES32(size) << (offset))
16 #define MLX5_MERGE_C(rsrc1, rsrc2, start, len) \
17 ((((rsrc2) << (start)) & (MLX5_MASK32((start), (len)))) | \
18 ((rsrc1) & (~MLX5_MASK32((start), (len)))))
19 #define MLX5_MERGE(rsrc1, rsrc2, start, len) \
20 (((len) == 32) ? (rsrc2) : MLX5_MERGE_C(rsrc1, rsrc2, start, len))
21 #define vsc_read(dev, offset, val) \
22 pci_read_config_dword((dev)->pdev, (dev)->vsc_addr + (offset), (val))
23 #define vsc_write(dev, offset, val) \
24 pci_write_config_dword((dev)->pdev, (dev)->vsc_addr + (offset), (val))
25 #define VSC_MAX_RETRIES 2048
26
27 enum {
28 VSC_CTRL_OFFSET = 0x4,
29 VSC_COUNTER_OFFSET = 0x8,
30 VSC_SEMAPHORE_OFFSET = 0xc,
31 VSC_ADDR_OFFSET = 0x10,
32 VSC_DATA_OFFSET = 0x14,
33
34 VSC_FLAG_BIT_OFFS = 31,
35 VSC_FLAG_BIT_LEN = 1,
36
37 VSC_SYND_BIT_OFFS = 30,
38 VSC_SYND_BIT_LEN = 1,
39
40 VSC_ADDR_BIT_OFFS = 0,
41 VSC_ADDR_BIT_LEN = 30,
42
43 VSC_SPACE_BIT_OFFS = 0,
44 VSC_SPACE_BIT_LEN = 16,
45
46 VSC_SIZE_VLD_BIT_OFFS = 28,
47 VSC_SIZE_VLD_BIT_LEN = 1,
48
49 VSC_STATUS_BIT_OFFS = 29,
50 VSC_STATUS_BIT_LEN = 3,
51 };
52
mlx5_pci_vsc_init(struct mlx5_core_dev * dev)53 void mlx5_pci_vsc_init(struct mlx5_core_dev *dev)
54 {
55 if (!mlx5_core_is_pf(dev))
56 return;
57
58 dev->vsc_addr = pci_find_capability(dev->pdev,
59 PCI_CAP_ID_VNDR);
60 if (!dev->vsc_addr)
61 mlx5_core_warn(dev, "Failed to get valid vendor specific ID\n");
62 }
63
mlx5_vsc_gw_lock(struct mlx5_core_dev * dev)64 int mlx5_vsc_gw_lock(struct mlx5_core_dev *dev)
65 {
66 u32 counter = 0;
67 int retries = 0;
68 u32 lock_val;
69 int ret;
70
71 pci_cfg_access_lock(dev->pdev);
72 do {
73 if (retries > VSC_MAX_RETRIES) {
74 ret = -EBUSY;
75 goto pci_unlock;
76 }
77
78 /* Check if semaphore is already locked */
79 ret = vsc_read(dev, VSC_SEMAPHORE_OFFSET, &lock_val);
80 if (ret)
81 goto pci_unlock;
82
83 if (lock_val) {
84 retries++;
85 usleep_range(1000, 2000);
86 continue;
87 }
88
89 /* Read and write counter value, if written value is
90 * the same, semaphore was acquired successfully.
91 */
92 ret = vsc_read(dev, VSC_COUNTER_OFFSET, &counter);
93 if (ret)
94 goto pci_unlock;
95
96 ret = vsc_write(dev, VSC_SEMAPHORE_OFFSET, counter);
97 if (ret)
98 goto pci_unlock;
99
100 ret = vsc_read(dev, VSC_SEMAPHORE_OFFSET, &lock_val);
101 if (ret)
102 goto pci_unlock;
103
104 retries++;
105 } while (counter != lock_val);
106
107 return 0;
108
109 pci_unlock:
110 pci_cfg_access_unlock(dev->pdev);
111 return ret;
112 }
113
mlx5_vsc_gw_unlock(struct mlx5_core_dev * dev)114 int mlx5_vsc_gw_unlock(struct mlx5_core_dev *dev)
115 {
116 int ret;
117
118 ret = vsc_write(dev, VSC_SEMAPHORE_OFFSET, MLX5_VSC_UNLOCK);
119 pci_cfg_access_unlock(dev->pdev);
120 return ret;
121 }
122
mlx5_vsc_gw_set_space(struct mlx5_core_dev * dev,u16 space,u32 * ret_space_size)123 int mlx5_vsc_gw_set_space(struct mlx5_core_dev *dev, u16 space,
124 u32 *ret_space_size)
125 {
126 int ret;
127 u32 val = 0;
128
129 if (!mlx5_vsc_accessible(dev))
130 return -EINVAL;
131
132 if (ret_space_size)
133 *ret_space_size = 0;
134
135 /* Get a unique val */
136 ret = vsc_read(dev, VSC_CTRL_OFFSET, &val);
137 if (ret)
138 goto out;
139
140 /* Try to modify the lock */
141 val = MLX5_MERGE(val, space, VSC_SPACE_BIT_OFFS, VSC_SPACE_BIT_LEN);
142 ret = vsc_write(dev, VSC_CTRL_OFFSET, val);
143 if (ret)
144 goto out;
145
146 /* Verify lock was modified */
147 ret = vsc_read(dev, VSC_CTRL_OFFSET, &val);
148 if (ret)
149 goto out;
150
151 if (MLX5_EXTRACT(val, VSC_STATUS_BIT_OFFS, VSC_STATUS_BIT_LEN) == 0)
152 return -EINVAL;
153
154 /* Get space max address if indicated by size valid bit */
155 if (ret_space_size &&
156 MLX5_EXTRACT(val, VSC_SIZE_VLD_BIT_OFFS, VSC_SIZE_VLD_BIT_LEN)) {
157 ret = vsc_read(dev, VSC_ADDR_OFFSET, &val);
158 if (ret) {
159 mlx5_core_warn(dev, "Failed to get max space size\n");
160 goto out;
161 }
162 *ret_space_size = MLX5_EXTRACT(val, VSC_ADDR_BIT_OFFS,
163 VSC_ADDR_BIT_LEN);
164 }
165 return 0;
166
167 out:
168 return ret;
169 }
170
mlx5_vsc_wait_on_flag(struct mlx5_core_dev * dev,u8 expected_val)171 static int mlx5_vsc_wait_on_flag(struct mlx5_core_dev *dev, u8 expected_val)
172 {
173 int retries = 0;
174 u32 flag;
175 int ret;
176
177 do {
178 if (retries > VSC_MAX_RETRIES)
179 return -EBUSY;
180
181 ret = vsc_read(dev, VSC_ADDR_OFFSET, &flag);
182 if (ret)
183 return ret;
184 flag = MLX5_EXTRACT(flag, VSC_FLAG_BIT_OFFS, VSC_FLAG_BIT_LEN);
185 retries++;
186
187 if ((retries & 0xf) == 0)
188 usleep_range(1000, 2000);
189
190 } while (flag != expected_val);
191
192 return 0;
193 }
194
mlx5_vsc_gw_write(struct mlx5_core_dev * dev,unsigned int address,u32 data)195 static int mlx5_vsc_gw_write(struct mlx5_core_dev *dev, unsigned int address,
196 u32 data)
197 {
198 int ret;
199
200 if (MLX5_EXTRACT(address, VSC_SYND_BIT_OFFS,
201 VSC_FLAG_BIT_LEN + VSC_SYND_BIT_LEN))
202 return -EINVAL;
203
204 /* Set flag to 0x1 */
205 address = MLX5_MERGE(address, 1, VSC_FLAG_BIT_OFFS, 1);
206 ret = vsc_write(dev, VSC_DATA_OFFSET, data);
207 if (ret)
208 goto out;
209
210 ret = vsc_write(dev, VSC_ADDR_OFFSET, address);
211 if (ret)
212 goto out;
213
214 /* Wait for the flag to be cleared */
215 ret = mlx5_vsc_wait_on_flag(dev, 0);
216
217 out:
218 return ret;
219 }
220
mlx5_vsc_gw_read(struct mlx5_core_dev * dev,unsigned int address,u32 * data)221 static int mlx5_vsc_gw_read(struct mlx5_core_dev *dev, unsigned int address,
222 u32 *data)
223 {
224 int ret;
225
226 if (MLX5_EXTRACT(address, VSC_SYND_BIT_OFFS,
227 VSC_FLAG_BIT_LEN + VSC_SYND_BIT_LEN))
228 return -EINVAL;
229
230 ret = vsc_write(dev, VSC_ADDR_OFFSET, address);
231 if (ret)
232 goto out;
233
234 ret = mlx5_vsc_wait_on_flag(dev, 1);
235 if (ret)
236 goto out;
237
238 ret = vsc_read(dev, VSC_DATA_OFFSET, data);
239 out:
240 return ret;
241 }
242
mlx5_vsc_gw_read_fast(struct mlx5_core_dev * dev,unsigned int read_addr,unsigned int * next_read_addr,u32 * data)243 static int mlx5_vsc_gw_read_fast(struct mlx5_core_dev *dev,
244 unsigned int read_addr,
245 unsigned int *next_read_addr,
246 u32 *data)
247 {
248 int ret;
249
250 ret = mlx5_vsc_gw_read(dev, read_addr, data);
251 if (ret)
252 goto out;
253
254 ret = vsc_read(dev, VSC_ADDR_OFFSET, next_read_addr);
255 if (ret)
256 goto out;
257
258 *next_read_addr = MLX5_EXTRACT(*next_read_addr, VSC_ADDR_BIT_OFFS,
259 VSC_ADDR_BIT_LEN);
260
261 if (*next_read_addr <= read_addr)
262 ret = -EINVAL;
263 out:
264 return ret;
265 }
266
mlx5_vsc_gw_read_block_fast(struct mlx5_core_dev * dev,u32 * data,int length)267 int mlx5_vsc_gw_read_block_fast(struct mlx5_core_dev *dev, u32 *data,
268 int length)
269 {
270 unsigned int next_read_addr = 0;
271 unsigned int read_addr = 0;
272
273 while (read_addr < length) {
274 if (mlx5_vsc_gw_read_fast(dev, read_addr, &next_read_addr,
275 &data[(read_addr >> 2)]))
276 return read_addr;
277
278 read_addr = next_read_addr;
279 }
280 return length;
281 }
282
mlx5_vsc_sem_set_space(struct mlx5_core_dev * dev,u16 space,enum mlx5_vsc_state state)283 int mlx5_vsc_sem_set_space(struct mlx5_core_dev *dev, u16 space,
284 enum mlx5_vsc_state state)
285 {
286 u32 data, id = 0;
287 int ret;
288
289 ret = mlx5_vsc_gw_set_space(dev, MLX5_SEMAPHORE_SPACE_DOMAIN, NULL);
290 if (ret) {
291 mlx5_core_warn(dev, "Failed to set gw space %d\n", ret);
292 return ret;
293 }
294
295 if (state == MLX5_VSC_LOCK) {
296 /* Get a unique ID based on the counter */
297 ret = vsc_read(dev, VSC_COUNTER_OFFSET, &id);
298 if (ret)
299 return ret;
300 }
301
302 /* Try to modify lock */
303 ret = mlx5_vsc_gw_write(dev, space, id);
304 if (ret)
305 return ret;
306
307 /* Verify lock was modified */
308 ret = mlx5_vsc_gw_read(dev, space, &data);
309 if (ret)
310 return -EINVAL;
311
312 if (data != id)
313 return -EBUSY;
314
315 return 0;
316 }
317