xref: /openbmc/linux/drivers/scsi/cxlflash/lunmgt.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  * CXL Flash Device Driver
3  *
4  * Written by: Manoj N. Kumar <manoj@linux.vnet.ibm.com>, IBM Corporation
5  *             Matthew R. Ochs <mrochs@linux.vnet.ibm.com>, IBM Corporation
6  *
7  * Copyright (C) 2015 IBM Corporation
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License
11  * as published by the Free Software Foundation; either version
12  * 2 of the License, or (at your option) any later version.
13  */
14 
15 #include <misc/cxl.h>
16 #include <asm/unaligned.h>
17 
18 #include <scsi/scsi_host.h>
19 #include <uapi/scsi/cxlflash_ioctl.h>
20 
21 #include "sislite.h"
22 #include "common.h"
23 #include "vlun.h"
24 #include "superpipe.h"
25 
26 /**
27  * create_local() - allocate and initialize a local LUN information structure
28  * @sdev:	SCSI device associated with LUN.
29  * @wwid:	World Wide Node Name for LUN.
30  *
31  * Return: Allocated local llun_info structure on success, NULL on failure
32  */
33 static struct llun_info *create_local(struct scsi_device *sdev, u8 *wwid)
34 {
35 	struct llun_info *lli = NULL;
36 
37 	lli = kzalloc(sizeof(*lli), GFP_KERNEL);
38 	if (unlikely(!lli)) {
39 		pr_err("%s: could not allocate lli\n", __func__);
40 		goto out;
41 	}
42 
43 	lli->sdev = sdev;
44 	lli->newly_created = true;
45 	lli->host_no = sdev->host->host_no;
46 	lli->in_table = false;
47 
48 	memcpy(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
49 out:
50 	return lli;
51 }
52 
53 /**
54  * create_global() - allocate and initialize a global LUN information structure
55  * @sdev:	SCSI device associated with LUN.
56  * @wwid:	World Wide Node Name for LUN.
57  *
58  * Return: Allocated global glun_info structure on success, NULL on failure
59  */
60 static struct glun_info *create_global(struct scsi_device *sdev, u8 *wwid)
61 {
62 	struct glun_info *gli = NULL;
63 
64 	gli = kzalloc(sizeof(*gli), GFP_KERNEL);
65 	if (unlikely(!gli)) {
66 		pr_err("%s: could not allocate gli\n", __func__);
67 		goto out;
68 	}
69 
70 	mutex_init(&gli->mutex);
71 	memcpy(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN);
72 out:
73 	return gli;
74 }
75 
76 /**
77  * refresh_local() - find and update local LUN information structure by WWID
78  * @cfg:	Internal structure associated with the host.
79  * @wwid:	WWID associated with LUN.
80  *
81  * When the LUN is found, mark it by updating it's newly_created field.
82  *
83  * Return: Found local lun_info structure on success, NULL on failure
84  * If a LUN with the WWID is found in the list, refresh it's state.
85  */
86 static struct llun_info *refresh_local(struct cxlflash_cfg *cfg, u8 *wwid)
87 {
88 	struct llun_info *lli, *temp;
89 
90 	list_for_each_entry_safe(lli, temp, &cfg->lluns, list)
91 		if (!memcmp(lli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN)) {
92 			lli->newly_created = false;
93 			return lli;
94 		}
95 
96 	return NULL;
97 }
98 
99 /**
100  * lookup_global() - find a global LUN information structure by WWID
101  * @wwid:	WWID associated with LUN.
102  *
103  * Return: Found global lun_info structure on success, NULL on failure
104  */
105 static struct glun_info *lookup_global(u8 *wwid)
106 {
107 	struct glun_info *gli, *temp;
108 
109 	list_for_each_entry_safe(gli, temp, &global.gluns, list)
110 		if (!memcmp(gli->wwid, wwid, DK_CXLFLASH_MANAGE_LUN_WWID_LEN))
111 			return gli;
112 
113 	return NULL;
114 }
115 
116 /**
117  * find_and_create_lun() - find or create a local LUN information structure
118  * @sdev:	SCSI device associated with LUN.
119  * @wwid:	WWID associated with LUN.
120  *
121  * The LUN is kept both in a local list (per adapter) and in a global list
122  * (across all adapters). Certain attributes of the LUN are local to the
123  * adapter (such as index, port selection mask etc.).
124  * The block allocation map is shared across all adapters (i.e. associated
125  * wih the global list). Since different attributes are associated with
126  * the per adapter and global entries, allocate two separate structures for each
127  * LUN (one local, one global).
128  *
129  * Keep a pointer back from the local to the global entry.
130  *
131  * Return: Found/Allocated local lun_info structure on success, NULL on failure
132  */
133 static struct llun_info *find_and_create_lun(struct scsi_device *sdev, u8 *wwid)
134 {
135 	struct llun_info *lli = NULL;
136 	struct glun_info *gli = NULL;
137 	struct Scsi_Host *shost = sdev->host;
138 	struct cxlflash_cfg *cfg = shost_priv(shost);
139 
140 	mutex_lock(&global.mutex);
141 	if (unlikely(!wwid))
142 		goto out;
143 
144 	lli = refresh_local(cfg, wwid);
145 	if (lli)
146 		goto out;
147 
148 	lli = create_local(sdev, wwid);
149 	if (unlikely(!lli))
150 		goto out;
151 
152 	gli = lookup_global(wwid);
153 	if (gli) {
154 		lli->parent = gli;
155 		list_add(&lli->list, &cfg->lluns);
156 		goto out;
157 	}
158 
159 	gli = create_global(sdev, wwid);
160 	if (unlikely(!gli)) {
161 		kfree(lli);
162 		lli = NULL;
163 		goto out;
164 	}
165 
166 	lli->parent = gli;
167 	list_add(&lli->list, &cfg->lluns);
168 
169 	list_add(&gli->list, &global.gluns);
170 
171 out:
172 	mutex_unlock(&global.mutex);
173 	pr_debug("%s: returning %p\n", __func__, lli);
174 	return lli;
175 }
176 
177 /**
178  * cxlflash_term_local_luns() - Delete all entries from local LUN list, free.
179  * @cfg:	Internal structure associated with the host.
180  */
181 void cxlflash_term_local_luns(struct cxlflash_cfg *cfg)
182 {
183 	struct llun_info *lli, *temp;
184 
185 	mutex_lock(&global.mutex);
186 	list_for_each_entry_safe(lli, temp, &cfg->lluns, list) {
187 		list_del(&lli->list);
188 		kfree(lli);
189 	}
190 	mutex_unlock(&global.mutex);
191 }
192 
193 /**
194  * cxlflash_list_init() - initializes the global LUN list
195  */
196 void cxlflash_list_init(void)
197 {
198 	INIT_LIST_HEAD(&global.gluns);
199 	mutex_init(&global.mutex);
200 	global.err_page = NULL;
201 }
202 
203 /**
204  * cxlflash_term_global_luns() - frees resources associated with global LUN list
205  */
206 void cxlflash_term_global_luns(void)
207 {
208 	struct glun_info *gli, *temp;
209 
210 	mutex_lock(&global.mutex);
211 	list_for_each_entry_safe(gli, temp, &global.gluns, list) {
212 		list_del(&gli->list);
213 		cxlflash_ba_terminate(&gli->blka.ba_lun);
214 		kfree(gli);
215 	}
216 	mutex_unlock(&global.mutex);
217 }
218 
219 /**
220  * cxlflash_manage_lun() - handles LUN management activities
221  * @sdev:	SCSI device associated with LUN.
222  * @manage:	Manage ioctl data structure.
223  *
224  * This routine is used to notify the driver about a LUN's WWID and associate
225  * SCSI devices (sdev) with a global LUN instance. Additionally it serves to
226  * change a LUN's operating mode: legacy or superpipe.
227  *
228  * Return: 0 on success, -errno on failure
229  */
230 int cxlflash_manage_lun(struct scsi_device *sdev,
231 			struct dk_cxlflash_manage_lun *manage)
232 {
233 	int rc = 0;
234 	struct llun_info *lli = NULL;
235 	u64 flags = manage->hdr.flags;
236 	u32 chan = sdev->channel;
237 
238 	lli = find_and_create_lun(sdev, manage->wwid);
239 	pr_debug("%s: ENTER: WWID = %016llX%016llX, flags = %016llX li = %p\n",
240 		 __func__, get_unaligned_le64(&manage->wwid[0]),
241 		 get_unaligned_le64(&manage->wwid[8]),
242 		 manage->hdr.flags, lli);
243 	if (unlikely(!lli)) {
244 		rc = -ENOMEM;
245 		goto out;
246 	}
247 
248 	if (flags & DK_CXLFLASH_MANAGE_LUN_ENABLE_SUPERPIPE) {
249 		if (lli->newly_created)
250 			lli->port_sel = CHAN2PORT(chan);
251 		else
252 			lli->port_sel = BOTH_PORTS;
253 		/* Store off lun in unpacked, AFU-friendly format */
254 		lli->lun_id[chan] = lun_to_lunid(sdev->lun);
255 		sdev->hostdata = lli;
256 	} else if (flags & DK_CXLFLASH_MANAGE_LUN_DISABLE_SUPERPIPE) {
257 		if (lli->parent->mode != MODE_NONE)
258 			rc = -EBUSY;
259 		else
260 			sdev->hostdata = NULL;
261 	}
262 
263 out:
264 	pr_debug("%s: returning rc=%d\n", __func__, rc);
265 	return rc;
266 }
267