xref: /linux/drivers/s390/char/sclp_sdias.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * SCLP "store data in absolute storage"
3  *
4  * Copyright IBM Corp. 2003, 2013
5  * Author(s): Michael Holzheu
6  */
7 
8 #define KMSG_COMPONENT "sclp_sdias"
9 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
10 
11 #include <linux/completion.h>
12 #include <linux/sched.h>
13 #include <asm/sclp.h>
14 #include <asm/debug.h>
15 #include <asm/ipl.h>
16 
17 #include "sclp_sdias.h"
18 #include "sclp.h"
19 #include "sclp_rw.h"
20 
21 #define TRACE(x...) debug_sprintf_event(sdias_dbf, 1, x)
22 
23 #define SDIAS_RETRIES 300
24 
25 static struct debug_info *sdias_dbf;
26 
27 static struct sclp_register sclp_sdias_register = {
28 	.send_mask = EVTYP_SDIAS_MASK,
29 };
30 
31 static struct sdias_sccb sccb __attribute__((aligned(4096)));
32 static struct sdias_evbuf sdias_evbuf;
33 
34 static DECLARE_COMPLETION(evbuf_accepted);
35 static DECLARE_COMPLETION(evbuf_done);
36 static DEFINE_MUTEX(sdias_mutex);
37 
38 /*
39  * Called by SCLP base when read event data has been completed (async mode only)
40  */
41 static void sclp_sdias_receiver_fn(struct evbuf_header *evbuf)
42 {
43 	memcpy(&sdias_evbuf, evbuf,
44 	       min_t(unsigned long, sizeof(sdias_evbuf), evbuf->length));
45 	complete(&evbuf_done);
46 	TRACE("sclp_sdias_receiver_fn done\n");
47 }
48 
49 /*
50  * Called by SCLP base when sdias event has been accepted
51  */
52 static void sdias_callback(struct sclp_req *request, void *data)
53 {
54 	complete(&evbuf_accepted);
55 	TRACE("callback done\n");
56 }
57 
58 static int sdias_sclp_send(struct sclp_req *req)
59 {
60 	int retries;
61 	int rc;
62 
63 	for (retries = SDIAS_RETRIES; retries; retries--) {
64 		TRACE("add request\n");
65 		rc = sclp_add_request(req);
66 		if (rc) {
67 			/* not initiated, wait some time and retry */
68 			set_current_state(TASK_INTERRUPTIBLE);
69 			TRACE("add request failed: rc = %i\n",rc);
70 			schedule_timeout(msecs_to_jiffies(500));
71 			continue;
72 		}
73 		/* initiated, wait for completion of service call */
74 		wait_for_completion(&evbuf_accepted);
75 		if (req->status == SCLP_REQ_FAILED) {
76 			TRACE("sclp request failed\n");
77 			continue;
78 		}
79 		/* if not accepted, retry */
80 		if (!(sccb.evbuf.hdr.flags & 0x80)) {
81 			TRACE("sclp request failed: flags=%x\n",
82 			      sccb.evbuf.hdr.flags);
83 			continue;
84 		}
85 		/*
86 		 * for the sync interface the response is in the initial sccb
87 		 */
88 		if (!sclp_sdias_register.receiver_fn) {
89 			memcpy(&sdias_evbuf, &sccb.evbuf, sizeof(sdias_evbuf));
90 			TRACE("sync request done\n");
91 			return 0;
92 		}
93 		/* otherwise we wait for completion */
94 		wait_for_completion(&evbuf_done);
95 		TRACE("request done\n");
96 		return 0;
97 	}
98 	return -EIO;
99 }
100 
101 /*
102  * Get number of blocks (4K) available in the HSA
103  */
104 int sclp_sdias_blk_count(void)
105 {
106 	struct sclp_req request;
107 	int rc;
108 
109 	mutex_lock(&sdias_mutex);
110 
111 	memset(&sccb, 0, sizeof(sccb));
112 	memset(&request, 0, sizeof(request));
113 
114 	sccb.hdr.length = sizeof(sccb);
115 	sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
116 	sccb.evbuf.hdr.type = EVTYP_SDIAS;
117 	sccb.evbuf.event_qual = SDIAS_EQ_SIZE;
118 	sccb.evbuf.data_id = SDIAS_DI_FCP_DUMP;
119 	sccb.evbuf.event_id = 4712;
120 	sccb.evbuf.dbs = 1;
121 
122 	request.sccb = &sccb;
123 	request.command = SCLP_CMDW_WRITE_EVENT_DATA;
124 	request.status = SCLP_REQ_FILLED;
125 	request.callback = sdias_callback;
126 
127 	rc = sdias_sclp_send(&request);
128 	if (rc) {
129 		pr_err("sclp_send failed for get_nr_blocks\n");
130 		goto out;
131 	}
132 	if (sccb.hdr.response_code != 0x0020) {
133 		TRACE("send failed: %x\n", sccb.hdr.response_code);
134 		rc = -EIO;
135 		goto out;
136 	}
137 
138 	switch (sdias_evbuf.event_status) {
139 		case 0:
140 			rc = sdias_evbuf.blk_cnt;
141 			break;
142 		default:
143 			pr_err("SCLP error: %x\n", sdias_evbuf.event_status);
144 			rc = -EIO;
145 			goto out;
146 	}
147 	TRACE("%i blocks\n", rc);
148 out:
149 	mutex_unlock(&sdias_mutex);
150 	return rc;
151 }
152 
153 /*
154  * Copy from HSA to absolute storage (not reentrant):
155  *
156  * @dest     : Address of buffer where data should be copied
157  * @start_blk: Start Block (beginning with 1)
158  * @nr_blks  : Number of 4K blocks to copy
159  *
160  * Return Value: 0 : Requested 'number' of blocks of data copied
161  *		 <0: ERROR - negative event status
162  */
163 int sclp_sdias_copy(void *dest, int start_blk, int nr_blks)
164 {
165 	struct sclp_req request;
166 	int rc;
167 
168 	mutex_lock(&sdias_mutex);
169 
170 	memset(&sccb, 0, sizeof(sccb));
171 	memset(&request, 0, sizeof(request));
172 
173 	sccb.hdr.length = sizeof(sccb);
174 	sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
175 	sccb.evbuf.hdr.type = EVTYP_SDIAS;
176 	sccb.evbuf.hdr.flags = 0;
177 	sccb.evbuf.event_qual = SDIAS_EQ_STORE_DATA;
178 	sccb.evbuf.data_id = SDIAS_DI_FCP_DUMP;
179 	sccb.evbuf.event_id = 4712;
180 	sccb.evbuf.asa_size = SDIAS_ASA_SIZE_64;
181 	sccb.evbuf.event_status = 0;
182 	sccb.evbuf.blk_cnt = nr_blks;
183 	sccb.evbuf.asa = (unsigned long)dest;
184 	sccb.evbuf.fbn = start_blk;
185 	sccb.evbuf.lbn = 0;
186 	sccb.evbuf.dbs = 1;
187 
188 	request.sccb	 = &sccb;
189 	request.command  = SCLP_CMDW_WRITE_EVENT_DATA;
190 	request.status	 = SCLP_REQ_FILLED;
191 	request.callback = sdias_callback;
192 
193 	rc = sdias_sclp_send(&request);
194 	if (rc) {
195 		pr_err("sclp_send failed: %x\n", rc);
196 		goto out;
197 	}
198 	if (sccb.hdr.response_code != 0x0020) {
199 		TRACE("copy failed: %x\n", sccb.hdr.response_code);
200 		rc = -EIO;
201 		goto out;
202 	}
203 
204 	switch (sdias_evbuf.event_status) {
205 	case SDIAS_EVSTATE_ALL_STORED:
206 		TRACE("all stored\n");
207 		break;
208 	case SDIAS_EVSTATE_PART_STORED:
209 		TRACE("part stored: %i\n", sdias_evbuf.blk_cnt);
210 		break;
211 	case SDIAS_EVSTATE_NO_DATA:
212 		TRACE("no data\n");
213 		/* fall through */
214 	default:
215 		pr_err("Error from SCLP while copying hsa. Event status = %x\n",
216 		       sdias_evbuf.event_status);
217 		rc = -EIO;
218 	}
219 out:
220 	mutex_unlock(&sdias_mutex);
221 	return rc;
222 }
223 
224 static int __init sclp_sdias_register_check(void)
225 {
226 	int rc;
227 
228 	rc = sclp_register(&sclp_sdias_register);
229 	if (rc)
230 		return rc;
231 	if (sclp_sdias_blk_count() == 0) {
232 		sclp_unregister(&sclp_sdias_register);
233 		return -ENODEV;
234 	}
235 	return 0;
236 }
237 
238 static int __init sclp_sdias_init_sync(void)
239 {
240 	TRACE("Try synchronous mode\n");
241 	sclp_sdias_register.receive_mask = 0;
242 	sclp_sdias_register.receiver_fn = NULL;
243 	return sclp_sdias_register_check();
244 }
245 
246 static int __init sclp_sdias_init_async(void)
247 {
248 	TRACE("Try asynchronous mode\n");
249 	sclp_sdias_register.receive_mask = EVTYP_SDIAS_MASK;
250 	sclp_sdias_register.receiver_fn = sclp_sdias_receiver_fn;
251 	return sclp_sdias_register_check();
252 }
253 
254 int __init sclp_sdias_init(void)
255 {
256 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
257 		return 0;
258 	sdias_dbf = debug_register("dump_sdias", 4, 1, 4 * sizeof(long));
259 	debug_register_view(sdias_dbf, &debug_sprintf_view);
260 	debug_set_level(sdias_dbf, 6);
261 	if (sclp_sdias_init_sync() == 0)
262 		goto out;
263 	if (sclp_sdias_init_async() == 0)
264 		goto out;
265 	TRACE("init failed\n");
266 	return -ENODEV;
267 out:
268 	TRACE("init done\n");
269 	return 0;
270 }
271 
272 void __exit sclp_sdias_exit(void)
273 {
274 	debug_unregister(sdias_dbf);
275 	sclp_unregister(&sclp_sdias_register);
276 }
277