pr.c

  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 <linux/unaligned.h>
  9
 10#include "nvme.h"
 11
 12static 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
 32static 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
 52static 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
 68static 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
 75static int nvme_status_to_pr_err(int status)
 76{
 77	if (nvme_is_path_error(status))
 78		return PR_STS_PATH_FAILED;
 79
 80	switch (status & NVME_SCT_SC_MASK) {
 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_BAD_ATTRIBUTES:
 86	case NVME_SC_INVALID_OPCODE:
 87	case NVME_SC_INVALID_FIELD:
 88	case NVME_SC_INVALID_NS:
 89		return -EINVAL;
 90	default:
 91		return PR_STS_IOERR;
 92	}
 93}
 94
 95static int __nvme_send_pr_command(struct block_device *bdev, u32 cdw10,
 96		u32 cdw11, u8 op, void *data, unsigned int data_len)
 97{
 98	struct nvme_command c = { 0 };
 99
100	c.common.opcode = op;
101	c.common.cdw10 = cpu_to_le32(cdw10);
102	c.common.cdw11 = cpu_to_le32(cdw11);
103
104	if (nvme_disk_is_ns_head(bdev->bd_disk))
105		return nvme_send_ns_head_pr_command(bdev, &c, data, data_len);
106	return nvme_send_ns_pr_command(bdev->bd_disk->private_data, &c,
107				data, data_len);
108}
109
110static int nvme_send_pr_command(struct block_device *bdev, u32 cdw10, u32 cdw11,
111		u8 op, void *data, unsigned int data_len)
112{
113	int ret;
114
115	ret = __nvme_send_pr_command(bdev, cdw10, cdw11, op, data, data_len);
116	return ret < 0 ? ret : nvme_status_to_pr_err(ret);
117}
118
119static int nvme_pr_register(struct block_device *bdev, u64 old_key, u64 new_key,
120		unsigned int flags)
121{
122	struct nvmet_pr_register_data data = { 0 };
123	u32 cdw10;
124
125	if (flags & ~PR_FL_IGNORE_KEY)
126		return -EOPNOTSUPP;
127
128	data.crkey = cpu_to_le64(old_key);
129	data.nrkey = cpu_to_le64(new_key);
130
131	cdw10 = old_key ? NVME_PR_REGISTER_ACT_REPLACE :
132		NVME_PR_REGISTER_ACT_REG;
133	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? NVME_PR_IGNORE_KEY : 0;
134	cdw10 |= NVME_PR_CPTPL_PERSIST;
135
136	return nvme_send_pr_command(bdev, cdw10, 0, nvme_cmd_resv_register,
137			&data, sizeof(data));
138}
139
140static int nvme_pr_reserve(struct block_device *bdev, u64 key,
141		enum pr_type type, unsigned flags)
142{
143	struct nvmet_pr_acquire_data data = { 0 };
144	u32 cdw10;
145
146	if (flags & ~PR_FL_IGNORE_KEY)
147		return -EOPNOTSUPP;
148
149	data.crkey = cpu_to_le64(key);
150
151	cdw10 = NVME_PR_ACQUIRE_ACT_ACQUIRE;
152	cdw10 |= nvme_pr_type_from_blk(type) << 8;
153	cdw10 |= (flags & PR_FL_IGNORE_KEY) ? NVME_PR_IGNORE_KEY : 0;
154
155	return nvme_send_pr_command(bdev, cdw10, 0, nvme_cmd_resv_acquire,
156			&data, sizeof(data));
157}
158
159static int nvme_pr_preempt(struct block_device *bdev, u64 old, u64 new,
160		enum pr_type type, bool abort)
161{
162	struct nvmet_pr_acquire_data data = { 0 };
163	u32 cdw10;
164
165	data.crkey = cpu_to_le64(old);
166	data.prkey = cpu_to_le64(new);
167
168	cdw10 = abort ? NVME_PR_ACQUIRE_ACT_PREEMPT_AND_ABORT :
169			NVME_PR_ACQUIRE_ACT_PREEMPT;
170	cdw10 |= nvme_pr_type_from_blk(type) << 8;
171
172	return nvme_send_pr_command(bdev, cdw10, 0, nvme_cmd_resv_acquire,
173			&data, sizeof(data));
174}
175
176static int nvme_pr_clear(struct block_device *bdev, u64 key)
177{
178	struct nvmet_pr_release_data data = { 0 };
179	u32 cdw10;
180
181	data.crkey = cpu_to_le64(key);
182
183	cdw10 = NVME_PR_RELEASE_ACT_CLEAR;
184	cdw10 |= key ? 0 : NVME_PR_IGNORE_KEY;
185
186	return nvme_send_pr_command(bdev, cdw10, 0, nvme_cmd_resv_release,
187			&data, sizeof(data));
188}
189
190static int nvme_pr_release(struct block_device *bdev, u64 key, enum pr_type type)
191{
192	struct nvmet_pr_release_data data = { 0 };
193	u32 cdw10;
194
195	data.crkey = cpu_to_le64(key);
196
197	cdw10 = NVME_PR_RELEASE_ACT_RELEASE;
198	cdw10 |= nvme_pr_type_from_blk(type) << 8;
199	cdw10 |= key ? 0 : NVME_PR_IGNORE_KEY;
200
201	return nvme_send_pr_command(bdev, cdw10, 0, nvme_cmd_resv_release,
202			&data, sizeof(data));
203}
204
205static int nvme_pr_resv_report(struct block_device *bdev, void *data,
206		u32 data_len, bool *eds)
207{
208	u32 cdw10, cdw11;
209	int ret;
210
211	cdw10 = nvme_bytes_to_numd(data_len);
212	cdw11 = NVME_EXTENDED_DATA_STRUCT;
213	*eds = true;
214
215retry:
216	ret = __nvme_send_pr_command(bdev, cdw10, cdw11, nvme_cmd_resv_report,
217			data, data_len);
218	if (ret == NVME_SC_HOST_ID_INCONSIST &&
219	    cdw11 == NVME_EXTENDED_DATA_STRUCT) {
220		cdw11 = 0;
221		*eds = false;
222		goto retry;
223	}
224
225	return ret < 0 ? ret : nvme_status_to_pr_err(ret);
226}
227
228static int nvme_pr_read_keys(struct block_device *bdev,
229		struct pr_keys *keys_info)
230{
231	size_t rse_len;
232	u32 num_keys = keys_info->num_keys;
233	struct nvme_reservation_status_ext *rse;
234	int ret, i;
235	bool eds;
236
237	/*
238	 * Assume we are using 128-bit host IDs and allocate a buffer large
239	 * enough to get enough keys to fill the return keys buffer.
240	 */
241	rse_len = struct_size(rse, regctl_eds, num_keys);
242	if (rse_len > U32_MAX)
243		return -EINVAL;
244
245	rse = kvzalloc(rse_len, GFP_KERNEL);
246	if (!rse)
247		return -ENOMEM;
248
249	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
250	if (ret)
251		goto free_rse;
252
253	keys_info->generation = le32_to_cpu(rse->gen);
254	keys_info->num_keys = get_unaligned_le16(&rse->regctl);
255
256	num_keys = min(num_keys, keys_info->num_keys);
257	for (i = 0; i < num_keys; i++) {
258		if (eds) {
259			keys_info->keys[i] =
260					le64_to_cpu(rse->regctl_eds[i].rkey);
261		} else {
262			struct nvme_reservation_status *rs;
263
264			rs = (struct nvme_reservation_status *)rse;
265			keys_info->keys[i] = le64_to_cpu(rs->regctl_ds[i].rkey);
266		}
267	}
268
269free_rse:
270	kvfree(rse);
271	return ret;
272}
273
274static int nvme_pr_read_reservation(struct block_device *bdev,
275		struct pr_held_reservation *resv)
276{
277	struct nvme_reservation_status_ext tmp_rse, *rse;
278	int ret, i, num_regs;
279	u32 rse_len;
280	bool eds;
281
282get_num_regs:
283	/*
284	 * Get the number of registrations so we know how big to allocate
285	 * the response buffer.
286	 */
287	ret = nvme_pr_resv_report(bdev, &tmp_rse, sizeof(tmp_rse), &eds);
288	if (ret)
289		return ret;
290
291	num_regs = get_unaligned_le16(&tmp_rse.regctl);
292	if (!num_regs) {
293		resv->generation = le32_to_cpu(tmp_rse.gen);
294		return 0;
295	}
296
297	rse_len = struct_size(rse, regctl_eds, num_regs);
298	rse = kzalloc(rse_len, GFP_KERNEL);
299	if (!rse)
300		return -ENOMEM;
301
302	ret = nvme_pr_resv_report(bdev, rse, rse_len, &eds);
303	if (ret)
304		goto free_rse;
305
306	if (num_regs != get_unaligned_le16(&rse->regctl)) {
307		kfree(rse);
308		goto get_num_regs;
309	}
310
311	resv->generation = le32_to_cpu(rse->gen);
312	resv->type = block_pr_type_from_nvme(rse->rtype);
313
314	for (i = 0; i < num_regs; i++) {
315		if (eds) {
316			if (rse->regctl_eds[i].rcsts) {
317				resv->key = le64_to_cpu(rse->regctl_eds[i].rkey);
318				break;
319			}
320		} else {
321			struct nvme_reservation_status *rs;
322
323			rs = (struct nvme_reservation_status *)rse;
324			if (rs->regctl_ds[i].rcsts) {
325				resv->key = le64_to_cpu(rs->regctl_ds[i].rkey);
326				break;
327			}
328		}
329	}
330
331free_rse:
332	kfree(rse);
333	return ret;
334}
335
336const struct pr_ops nvme_pr_ops = {
337	.pr_register	= nvme_pr_register,
338	.pr_reserve	= nvme_pr_reserve,
339	.pr_release	= nvme_pr_release,
340	.pr_preempt	= nvme_pr_preempt,
341	.pr_clear	= nvme_pr_clear,
342	.pr_read_keys	= nvme_pr_read_keys,
343	.pr_read_reservation = nvme_pr_read_reservation,
344};