xref: /openbmc/linux/drivers/scsi/lpfc/lpfc_vmid.c (revision dd5e5554)
1 /*******************************************************************
2  * This file is part of the Emulex Linux Device Driver for         *
3  * Fibre Channel Host Bus Adapters.                                *
4  * Copyright (C) 2017-2022 Broadcom. All Rights Reserved. The term *
5  * “Broadcom” refers to Broadcom Inc. and/or its subsidiaries.     *
6  * Copyright (C) 2004-2016 Emulex.  All rights reserved.           *
7  * EMULEX and SLI are trademarks of Emulex.                        *
8  * www.broadcom.com                                                *
9  * Portions Copyright (C) 2004-2005 Christoph Hellwig              *
10  *                                                                 *
11  * This program is free software; you can redistribute it and/or   *
12  * modify it under the terms of version 2 of the GNU General       *
13  * Public License as published by the Free Software Foundation.    *
14  * This program is distributed in the hope that it will be useful. *
15  * ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND          *
16  * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,  *
17  * FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE      *
18  * DISCLAIMED, EXCEPT TO THE EXTENT THAT SUCH DISCLAIMERS ARE HELD *
19  * TO BE LEGALLY INVALID.  See the GNU General Public License for  *
20  * more details, a copy of which can be found in the file COPYING  *
21  * included with this package.                                     *
22  *******************************************************************/
23 
24 #include <linux/interrupt.h>
25 #include <linux/dma-direction.h>
26 
27 #include <scsi/scsi_transport_fc.h>
28 
29 #include "lpfc_hw4.h"
30 #include "lpfc_hw.h"
31 #include "lpfc_sli.h"
32 #include "lpfc_sli4.h"
33 #include "lpfc_nl.h"
34 #include "lpfc_disc.h"
35 #include "lpfc.h"
36 #include "lpfc_crtn.h"
37 
38 
39 /*
40  * lpfc_get_vmid_from_hashtable - search the UUID in the hash table
41  * @vport: The virtual port for which this call is being executed.
42  * @hash: calculated hash value
43  * @buf: uuid associated with the VE
44  * Return the VMID entry associated with the UUID
45  * Make sure to acquire the appropriate lock before invoking this routine.
46  */
47 struct lpfc_vmid *lpfc_get_vmid_from_hashtable(struct lpfc_vport *vport,
48 					       u32 hash, u8 *buf)
49 {
50 	struct lpfc_vmid *vmp;
51 
52 	hash_for_each_possible(vport->hash_table, vmp, hnode, hash) {
53 		if (memcmp(&vmp->host_vmid[0], buf, 16) == 0)
54 			return vmp;
55 	}
56 	return NULL;
57 }
58 
59 /*
60  * lpfc_put_vmid_in_hashtable - put the VMID in the hash table
61  * @vport: The virtual port for which this call is being executed.
62  * @hash - calculated hash value
63  * @vmp: Pointer to a VMID entry representing a VM sending I/O
64  *
65  * This routine will insert the newly acquired VMID entity in the hash table.
66  * Make sure to acquire the appropriate lock before invoking this routine.
67  */
68 static void
69 lpfc_put_vmid_in_hashtable(struct lpfc_vport *vport, u32 hash,
70 			   struct lpfc_vmid *vmp)
71 {
72 	hash_add(vport->hash_table, &vmp->hnode, hash);
73 }
74 
75 /*
76  * lpfc_vmid_hash_fn - create a hash value of the UUID
77  * @vmid: uuid associated with the VE
78  * @len: length of the VMID string
79  * Returns the calculated hash value
80  */
81 int lpfc_vmid_hash_fn(const char *vmid, int len)
82 {
83 	int c;
84 	int hash = 0;
85 
86 	if (len == 0)
87 		return 0;
88 	while (len--) {
89 		c = *vmid++;
90 		if (c >= 'A' && c <= 'Z')
91 			c += 'a' - 'A';
92 
93 		hash = (hash + (c << LPFC_VMID_HASH_SHIFT) +
94 			(c >> LPFC_VMID_HASH_SHIFT)) * 19;
95 	}
96 
97 	return hash & LPFC_VMID_HASH_MASK;
98 }
99 
100 /*
101  * lpfc_vmid_update_entry - update the vmid entry in the hash table
102  * @vport: The virtual port for which this call is being executed.
103  * @iodir: io direction
104  * @vmp: Pointer to a VMID entry representing a VM sending I/O
105  * @tag: VMID tag
106  */
107 static void lpfc_vmid_update_entry(struct lpfc_vport *vport,
108 				   enum dma_data_direction iodir,
109 				   struct lpfc_vmid *vmp,
110 				   union lpfc_vmid_io_tag *tag)
111 {
112 	u64 *lta;
113 
114 	if (vport->phba->pport->vmid_flag & LPFC_VMID_TYPE_PRIO)
115 		tag->cs_ctl_vmid = vmp->un.cs_ctl_vmid;
116 	else if (vport->phba->cfg_vmid_app_header)
117 		tag->app_id = vmp->un.app_id;
118 
119 	if (iodir == DMA_TO_DEVICE)
120 		vmp->io_wr_cnt++;
121 	else if (iodir == DMA_FROM_DEVICE)
122 		vmp->io_rd_cnt++;
123 
124 	/* update the last access timestamp in the table */
125 	lta = per_cpu_ptr(vmp->last_io_time, raw_smp_processor_id());
126 	*lta = jiffies;
127 }
128 
129 static void lpfc_vmid_assign_cs_ctl(struct lpfc_vport *vport,
130 				    struct lpfc_vmid *vmid)
131 {
132 	u32 hash;
133 	struct lpfc_vmid *pvmid;
134 
135 	if (vport->port_type == LPFC_PHYSICAL_PORT) {
136 		vmid->un.cs_ctl_vmid = lpfc_vmid_get_cs_ctl(vport);
137 	} else {
138 		hash = lpfc_vmid_hash_fn(vmid->host_vmid, vmid->vmid_len);
139 		pvmid =
140 		    lpfc_get_vmid_from_hashtable(vport->phba->pport, hash,
141 						 vmid->host_vmid);
142 		if (pvmid)
143 			vmid->un.cs_ctl_vmid = pvmid->un.cs_ctl_vmid;
144 		else
145 			vmid->un.cs_ctl_vmid = lpfc_vmid_get_cs_ctl(vport);
146 	}
147 }
148 
149 /*
150  * lpfc_vmid_get_appid - get the VMID associated with the UUID
151  * @vport: The virtual port for which this call is being executed.
152  * @uuid: UUID associated with the VE
153  * @cmd: address of scsi_cmd descriptor
154  * @iodir: io direction
155  * @tag: VMID tag
156  * Returns status of the function
157  */
158 int lpfc_vmid_get_appid(struct lpfc_vport *vport, char *uuid,
159 			enum dma_data_direction iodir,
160 			union lpfc_vmid_io_tag *tag)
161 {
162 	struct lpfc_vmid *vmp = NULL;
163 	int hash, len, rc = -EPERM, i;
164 
165 	/* check if QFPA is complete */
166 	if (lpfc_vmid_is_type_priority_tag(vport) &&
167 	    !(vport->vmid_flag & LPFC_VMID_QFPA_CMPL) &&
168 	    (vport->vmid_flag & LPFC_VMID_ISSUE_QFPA)) {
169 		vport->work_port_events |= WORKER_CHECK_VMID_ISSUE_QFPA;
170 		return -EAGAIN;
171 	}
172 
173 	/* search if the UUID has already been mapped to the VMID */
174 	len = strlen(uuid);
175 	hash = lpfc_vmid_hash_fn(uuid, len);
176 
177 	/* search for the VMID in the table */
178 	read_lock(&vport->vmid_lock);
179 	vmp = lpfc_get_vmid_from_hashtable(vport, hash, uuid);
180 
181 	/* if found, check if its already registered  */
182 	if (vmp  && vmp->flag & LPFC_VMID_REGISTERED) {
183 		read_unlock(&vport->vmid_lock);
184 		lpfc_vmid_update_entry(vport, iodir, vmp, tag);
185 		rc = 0;
186 	} else if (vmp && (vmp->flag & LPFC_VMID_REQ_REGISTER ||
187 			   vmp->flag & LPFC_VMID_DE_REGISTER)) {
188 		/* else if register or dereg request has already been sent */
189 		/* Hence VMID tag will not be added for this I/O */
190 		read_unlock(&vport->vmid_lock);
191 		rc = -EBUSY;
192 	} else {
193 		/* The VMID was not found in the hashtable. At this point, */
194 		/* drop the read lock first before proceeding further */
195 		read_unlock(&vport->vmid_lock);
196 		/* start the process to obtain one as per the */
197 		/* type of the VMID indicated */
198 		write_lock(&vport->vmid_lock);
199 		vmp = lpfc_get_vmid_from_hashtable(vport, hash, uuid);
200 
201 		/* while the read lock was released, in case the entry was */
202 		/* added by other context or is in process of being added */
203 		if (vmp && vmp->flag & LPFC_VMID_REGISTERED) {
204 			lpfc_vmid_update_entry(vport, iodir, vmp, tag);
205 			write_unlock(&vport->vmid_lock);
206 			return 0;
207 		} else if (vmp && vmp->flag & LPFC_VMID_REQ_REGISTER) {
208 			write_unlock(&vport->vmid_lock);
209 			return -EBUSY;
210 		}
211 
212 		/* else search and allocate a free slot in the hash table */
213 		if (vport->cur_vmid_cnt < vport->max_vmid) {
214 			for (i = 0; i < vport->max_vmid; i++) {
215 				vmp = vport->vmid + i;
216 				if (vmp->flag == LPFC_VMID_SLOT_FREE)
217 					break;
218 			}
219 			if (i == vport->max_vmid)
220 				vmp = NULL;
221 		} else {
222 			vmp = NULL;
223 		}
224 
225 		if (!vmp) {
226 			write_unlock(&vport->vmid_lock);
227 			return -ENOMEM;
228 		}
229 
230 		/* Add the vmid and register */
231 		lpfc_put_vmid_in_hashtable(vport, hash, vmp);
232 		vmp->vmid_len = len;
233 		memcpy(vmp->host_vmid, uuid, vmp->vmid_len);
234 		vmp->io_rd_cnt = 0;
235 		vmp->io_wr_cnt = 0;
236 		vmp->flag = LPFC_VMID_SLOT_USED;
237 
238 		vmp->delete_inactive =
239 			vport->vmid_inactivity_timeout ? 1 : 0;
240 
241 		/* if type priority tag, get next available VMID */
242 		if (vport->phba->pport->vmid_flag & LPFC_VMID_TYPE_PRIO)
243 			lpfc_vmid_assign_cs_ctl(vport, vmp);
244 
245 		/* allocate the per cpu variable for holding */
246 		/* the last access time stamp only if VMID is enabled */
247 		if (!vmp->last_io_time)
248 			vmp->last_io_time = __alloc_percpu(sizeof(u64),
249 							   __alignof__(struct
250 							   lpfc_vmid));
251 		if (!vmp->last_io_time) {
252 			hash_del(&vmp->hnode);
253 			vmp->flag = LPFC_VMID_SLOT_FREE;
254 			write_unlock(&vport->vmid_lock);
255 			return -EIO;
256 		}
257 
258 		write_unlock(&vport->vmid_lock);
259 
260 		/* complete transaction with switch */
261 		if (vport->phba->pport->vmid_flag & LPFC_VMID_TYPE_PRIO)
262 			rc = lpfc_vmid_uvem(vport, vmp, true);
263 		else if (vport->phba->cfg_vmid_app_header)
264 			rc = lpfc_vmid_cmd(vport, SLI_CTAS_RAPP_IDENT, vmp);
265 		if (!rc) {
266 			write_lock(&vport->vmid_lock);
267 			vport->cur_vmid_cnt++;
268 			vmp->flag |= LPFC_VMID_REQ_REGISTER;
269 			write_unlock(&vport->vmid_lock);
270 		} else {
271 			write_lock(&vport->vmid_lock);
272 			hash_del(&vmp->hnode);
273 			vmp->flag = LPFC_VMID_SLOT_FREE;
274 			free_percpu(vmp->last_io_time);
275 			write_unlock(&vport->vmid_lock);
276 			return -EIO;
277 		}
278 
279 		/* finally, enable the idle timer once */
280 		if (!(vport->phba->pport->vmid_flag & LPFC_VMID_TIMER_ENBLD)) {
281 			mod_timer(&vport->phba->inactive_vmid_poll,
282 				  jiffies +
283 				  msecs_to_jiffies(1000 * LPFC_VMID_TIMER));
284 			vport->phba->pport->vmid_flag |= LPFC_VMID_TIMER_ENBLD;
285 		}
286 	}
287 	return rc;
288 }
289