xref: /linux/drivers/nvme/host/pr.c (revision db10cb9b) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2015 Intel Corporation
4  *	Keith Busch <kbusch@kernel.org>
5  */
6 #include <linux/blkdev.h>
7 #include <linux/pr.h>
8 #include <asm/unaligned.h>
9 
10 #include "nvme.h"
11 
12 static enum nvme_pr_type nvme_pr_type_from_blk(enum pr_type type)
13 {
14 	switch (type) {
15 	case PR_WRITE_EXCLUSIVE:
16 		return NVME_PR_WRITE_EXCLUSIVE;
17 	case PR_EXCLUSIVE_ACCESS:
18 		return NVME_PR_EXCLUSIVE_ACCESS;
19 	case PR_WRITE_EXCLUSIVE_REG_ONLY:
20 		return NVME_PR_WRITE_EXCLUSIVE_REG_ONLY;
21 	case PR_EXCLUSIVE_ACCESS_REG_ONLY:
22 		return NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY;
23 	case PR_WRITE_EXCLUSIVE_ALL_REGS:
24 		return NVME_PR_WRITE_EXCLUSIVE_ALL_REGS;
25 	case PR_EXCLUSIVE_ACCESS_ALL_REGS:
26 		return NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS;
27 	}
28 
29 	return 0;
30 }
31 
32 static enum pr_type block_pr_type_from_nvme(enum nvme_pr_type type)
33 {
34 	switch (type) {
35 	case NVME_PR_WRITE_EXCLUSIVE:
36 		return PR_WRITE_EXCLUSIVE;
37 	case NVME_PR_EXCLUSIVE_ACCESS:
38 		return PR_EXCLUSIVE_ACCESS;
39 	case NVME_PR_WRITE_EXCLUSIVE_REG_ONLY:
40 		return PR_WRITE_EXCLUSIVE_REG_ONLY;
41 	case NVME_PR_EXCLUSIVE_ACCESS_REG_ONLY:
42 		return PR_EXCLUSIVE_ACCESS_REG_ONLY;
43 	case NVME_PR_WRITE_EXCLUSIVE_ALL_REGS:
44 		return PR_WRITE_EXCLUSIVE_ALL_REGS;
45 	case NVME_PR_EXCLUSIVE_ACCESS_ALL_REGS:
46 		return PR_EXCLUSIVE_ACCESS_ALL_REGS;
47 	}
48 
49 	return 0;
50 }
51 
52 static int nvme_send_ns_head_pr_command(struct block_device *bdev,
53 		struct nvme_command *c, void *data, unsigned int data_len)
54 {
55 	struct nvme_ns_head *head = bdev->bd_disk->private_data;
56 	int srcu_idx = srcu_read_lock(&head->srcu);
57 	struct nvme_ns *ns = nvme_find_path(head);
58 	int ret = -EWOULDBLOCK;
59 
60 	if (ns) {
61 		c->common.nsid = cpu_to_le32(ns->head->ns_id);
62 		ret = nvme_submit_sync_cmd(ns->queue, c, data, data_len);
63 	}
64 	srcu_read_unlock(&head->srcu, srcu_idx);
65 	return ret;
66 }
67 
68 static int nvme_send_ns_pr_command(struct nvme_ns *ns, struct nvme_command *c,
69 		void *data, unsigned int data_len)
70 {
71 	c->common.nsid = cpu_to_le32(ns->head->ns_id);
72 	return nvme_submit_sync_cmd(ns->queue, c, data, data_len);
73 }
74 
75 static int nvme_sc_to_pr_err(int nvme_sc)
76 {
77 	if (nvme_is_path_error(nvme_sc))
78 		return PR_STS_PATH_FAILED;
79 
80 	switch (nvme_sc) {
81 	case NVME_SC_SUCCESS:
82 		return PR_STS_SUCCESS;
83 	case NVME_SC_RESERVATION_CONFLICT:
84 		return PR_STS_RESERVATION_CONFLICT;
85 	case NVME_SC_ONCS_NOT_SUPPORTED:
86 		return -EOPNOTSUPP;
87 	case NVME_SC_BAD_ATTRIBUTES:
88 	case NVME_SC_INVALID_OPCODE:
89 	case NVME_SC_INVALID_FIELD:
90 	case NVME_SC_INVALID_NS:
91 		return -EINVAL;
92 	default:
93 		return PR_STS_IOERR;
94 	}
95 }
96 
97 static int nvme_send_pr_command(struct block_device *bdev,
98 		struct nvme_command *c, void *data, unsigned int data_len)
99 {
100 	if (IS_ENABLED(CONFIG_NVME_MULTIPATH) &&
101 	    bdev->bd_disk->fops == &nvme_ns_head_ops)
102 		return nvme_send_ns_head_pr_command(bdev, c, data, data_len);
103 
104 	return nvme_send_ns_pr_command(bdev->bd_disk->private_data, c, data,
105 				       data_len);
106 }
107 
108 static int nvme_pr_command(struct block_device *bdev, u32 cdw10,
109 				u64 key, u64 sa_key, u8 op)
110 {
111 	struct nvme_command c = { };
112 	u8 data[16] = { 0, };
113 	int ret;
114 
115 	put_unaligned_le64(key, &data[0]);
116 	put_unaligned_le64(sa_key, &data[8]);
117 
118 	c.common.opcode = op;
119 	c.common.cdw10 = cpu_to_le32(cdw10);
120 
121 	ret = nvme_send_pr_command(bdev, &c, data, sizeof(data));
122 	if (ret < 0)
123 		return ret;
124 
125 	return nvme_sc_to_pr_err(ret);
126 }
127 
128 static int nvme_pr_register(struct block_device *bdev, u64 old,
129 		u64 new, unsigned flags)
130 {
131 	u32 cdw10;
132 
133 	if (flags & ~PR_FL_IGNORE_KEY)
134 		return -EOPNOTSUPP;
135 
136 	cdw10 = old ? 2 : 0;
137 	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0;
138 	cdw10 |= (1 << 30) | (1 << 31); /* PTPL=1 */
139 	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_register);
140 }
141 
142 static int nvme_pr_reserve(struct block_device *bdev, u64 key,
143 		enum pr_type type, unsigned flags)
144 {
145 	u32 cdw10;
146 
147 	if (flags & ~PR_FL_IGNORE_KEY)
148 		return -EOPNOTSUPP;
149 
150 	cdw10 = nvme_pr_type_from_blk(type) << 8;
151 	cdw10 |= ((flags & PR_FL_IGNORE_KEY) ? 1 << 3 : 0);
152 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_acquire);
153 }
154 
155 static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
156 		enum pr_type type, bool abort)
157 {
158 	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (abort ? 2 : 1);
159 
160 	return nvme_pr_command(bdev, cdw10, old, new, nvme_cmd_resv_acquire);
161 }
162 
163 static int nvme_pr_clear(struct block_device *bdev, u64 key)
164 {
165 	u32 cdw10 = 1 | (key ? 0 : 1 << 3);
166 
167 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
168 }
169 
170 static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
171 {
172 	u32 cdw10 = nvme_pr_type_from_blk(type) << 8 | (key ? 0 : 1 << 3);
173 
174 	return nvme_pr_command(bdev, cdw10, key, 0, nvme_cmd_resv_release);
175 }
176 
177 static int nvme_pr_resv_report(struct block_device *bdev, void *data,
178 		u32 data_len, bool *eds)
179 {
180 	struct nvme_command c = { };
181 	int ret;
182 
183 	c.common.opcode = nvme_cmd_resv_report;
184 	c.common.cdw10 = cpu_to_le32(nvme_bytes_to_numd(data_len));
185 	c.common.cdw11 = cpu_to_le32(NVME_EXTENDED_DATA_STRUCT);
186 	*eds = true;
187 
188 retry:
189 	ret = nvme_send_pr_command(bdev, &c, data, data_len);
190 	if (ret == NVME_SC_HOST_ID_INCONSIST &&
191 	    c.common.cdw11 == cpu_to_le32(NVME_EXTENDED_DATA_STRUCT)) {
192 		c.common.cdw11 = 0;
193 		*eds = false;
194 		goto retry;
195 	}
196 
197 	if (ret < 0)
198 		return ret;
199 
200 	return nvme_sc_to_pr_err(ret);
201 }
202 
203 static int nvme_pr_read_keys(struct block_device *bdev,
204 		struct pr_keys *keys_info)
205 {
206 	u32 rse_len, num_keys = keys_info->num_keys;
207 	struct nvme_reservation_status_ext *rse;
208 	int ret, i;
209 	bool eds;
210 
211 	/*
212 	 * Assume we are using 128-bit host IDs and allocate a buffer large
213 	 * enough to get enough keys to fill the return keys buffer.
214 	 */
215 	rse_len = struct_size(rse, regctl_eds, num_keys);
216 	rse = kzalloc(rse_len, GFP_KERNEL);
217 	if (!rse)
218 		return -ENOMEM;
219 
220 	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
221 	if (ret)
222 		goto free_rse;
223 
224 	keys_info->generation = le32_to_cpu(rse->gen);
225 	keys_info->num_keys = get_unaligned_le16(&rse->regctl);
226 
227 	num_keys = min(num_keys, keys_info->num_keys);
228 	for (i = 0; i < num_keys; i++) {
229 		if (eds) {
230 			keys_info->keys[i] =
231 					le64_to_cpu(rse->regctl_eds[i].rkey);
232 		} else {
233 			struct nvme_reservation_status *rs;
234 
235 			rs = (struct nvme_reservation_status *)rse;
236 			keys_info->keys[i] = le64_to_cpu(rs->regctl_ds[i].rkey);
237 		}
238 	}
239 
240 free_rse:
241 	kfree(rse);
242 	return ret;
243 }
244 
245 static int nvme_pr_read_reservation(struct block_device *bdev,
246 		struct pr_held_reservation *resv)
247 {
248 	struct nvme_reservation_status_ext tmp_rse, *rse;
249 	int ret, i, num_regs;
250 	u32 rse_len;
251 	bool eds;
252 
253 get_num_regs:
254 	/*
255 	 * Get the number of registrations so we know how big to allocate
256 	 * the response buffer.
257 	 */
258 	ret = nvme_pr_resv_report(bdev, &tmp_rse, sizeof(tmp_rse), &eds);
259 	if (ret)
260 		return ret;
261 
262 	num_regs = get_unaligned_le16(&tmp_rse.regctl);
263 	if (!num_regs) {
264 		resv->generation = le32_to_cpu(tmp_rse.gen);
265 		return 0;
266 	}
267 
268 	rse_len = struct_size(rse, regctl_eds, num_regs);
269 	rse = kzalloc(rse_len, GFP_KERNEL);
270 	if (!rse)
271 		return -ENOMEM;
272 
273 	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
274 	if (ret)
275 		goto free_rse;
276 
277 	if (num_regs != get_unaligned_le16(&rse->regctl)) {
278 		kfree(rse);
279 		goto get_num_regs;
280 	}
281 
282 	resv->generation = le32_to_cpu(rse->gen);
283 	resv->type = block_pr_type_from_nvme(rse->rtype);
284 
285 	for (i = 0; i < num_regs; i++) {
286 		if (eds) {
287 			if (rse->regctl_eds[i].rcsts) {
288 				resv->key = le64_to_cpu(rse->regctl_eds[i].rkey);
289 				break;
290 			}
291 		} else {
292 			struct nvme_reservation_status *rs;
293 
294 			rs = (struct nvme_reservation_status *)rse;
295 			if (rs->regctl_ds[i].rcsts) {
296 				resv->key = le64_to_cpu(rs->regctl_ds[i].rkey);
297 				break;
298 			}
299 		}
300 	}
301 
302 free_rse:
303 	kfree(rse);
304 	return ret;
305 }
306 
307 const struct pr_ops nvme_pr_ops = {
308 	.pr_register	= nvme_pr_register,
309 	.pr_reserve	= nvme_pr_reserve,
310 	.pr_release	= nvme_pr_release,
311 	.pr_preempt	= nvme_pr_preempt,
312 	.pr_clear	= nvme_pr_clear,
313 	.pr_read_keys	= nvme_pr_read_keys,
314 	.pr_read_reservation = nvme_pr_read_reservation,
315 };
316