xref: /openbmc/linux/drivers/s390/char/sclp_sdias.c (revision fd589a8f)
1 /*
2  * Sclp "store data in absolut storage"
3  *
4  * Copyright IBM Corp. 2003,2007
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/sched.h>
12 #include <asm/sclp.h>
13 #include <asm/debug.h>
14 #include <asm/ipl.h>
15 
16 #include "sclp.h"
17 #include "sclp_rw.h"
18 
19 #define TRACE(x...) debug_sprintf_event(sdias_dbf, 1, x)
20 
21 #define SDIAS_RETRIES 300
22 #define SDIAS_SLEEP_TICKS 50
23 
24 #define EQ_STORE_DATA	0x0
25 #define EQ_SIZE		0x1
26 #define DI_FCP_DUMP	0x0
27 #define ASA_SIZE_32	0x0
28 #define ASA_SIZE_64	0x1
29 #define EVSTATE_ALL_STORED	0x0
30 #define EVSTATE_NO_DATA		0x3
31 #define EVSTATE_PART_STORED	0x10
32 
33 static struct debug_info *sdias_dbf;
34 
35 static struct sclp_register sclp_sdias_register = {
36 	.send_mask = EVTYP_SDIAS_MASK,
37 };
38 
39 struct sdias_evbuf {
40 	struct	evbuf_header hdr;
41 	u8	event_qual;
42 	u8	data_id;
43 	u64	reserved2;
44 	u32	event_id;
45 	u16	reserved3;
46 	u8	asa_size;
47 	u8	event_status;
48 	u32	reserved4;
49 	u32	blk_cnt;
50 	u64	asa;
51 	u32	reserved5;
52 	u32	fbn;
53 	u32	reserved6;
54 	u32	lbn;
55 	u16	reserved7;
56 	u16	dbs;
57 } __attribute__((packed));
58 
59 struct sdias_sccb {
60 	struct sccb_header  hdr;
61 	struct sdias_evbuf  evbuf;
62 } __attribute__((packed));
63 
64 static struct sdias_sccb sccb __attribute__((aligned(4096)));
65 
66 static int sclp_req_done;
67 static wait_queue_head_t sdias_wq;
68 static DEFINE_MUTEX(sdias_mutex);
69 
70 static void sdias_callback(struct sclp_req *request, void *data)
71 {
72 	struct sdias_sccb *cbsccb;
73 
74 	cbsccb = (struct sdias_sccb *) request->sccb;
75 	sclp_req_done = 1;
76 	wake_up(&sdias_wq); /* Inform caller, that request is complete */
77 	TRACE("callback done\n");
78 }
79 
80 static int sdias_sclp_send(struct sclp_req *req)
81 {
82 	int retries;
83 	int rc;
84 
85 	for (retries = SDIAS_RETRIES; retries; retries--) {
86 		sclp_req_done = 0;
87 		TRACE("add request\n");
88 		rc = sclp_add_request(req);
89 		if (rc) {
90 			/* not initiated, wait some time and retry */
91 			set_current_state(TASK_INTERRUPTIBLE);
92 			TRACE("add request failed: rc = %i\n",rc);
93 			schedule_timeout(SDIAS_SLEEP_TICKS);
94 			continue;
95 		}
96 		/* initiated, wait for completion of service call */
97 		wait_event(sdias_wq, (sclp_req_done == 1));
98 		if (req->status == SCLP_REQ_FAILED) {
99 			TRACE("sclp request failed\n");
100 			rc = -EIO;
101 			continue;
102 		}
103 		TRACE("request done\n");
104 		break;
105 	}
106 	return rc;
107 }
108 
109 /*
110  * Get number of blocks (4K) available in the HSA
111  */
112 int sclp_sdias_blk_count(void)
113 {
114 	struct sclp_req request;
115 	int rc;
116 
117 	mutex_lock(&sdias_mutex);
118 
119 	memset(&sccb, 0, sizeof(sccb));
120 	memset(&request, 0, sizeof(request));
121 
122 	sccb.hdr.length = sizeof(sccb);
123 	sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
124 	sccb.evbuf.hdr.type = EVTYP_SDIAS;
125 	sccb.evbuf.event_qual = EQ_SIZE;
126 	sccb.evbuf.data_id = DI_FCP_DUMP;
127 	sccb.evbuf.event_id = 4712;
128 	sccb.evbuf.dbs = 1;
129 
130 	request.sccb = &sccb;
131 	request.command = SCLP_CMDW_WRITE_EVENT_DATA;
132 	request.status = SCLP_REQ_FILLED;
133 	request.callback = sdias_callback;
134 
135 	rc = sdias_sclp_send(&request);
136 	if (rc) {
137 		pr_err("sclp_send failed for get_nr_blocks\n");
138 		goto out;
139 	}
140 	if (sccb.hdr.response_code != 0x0020) {
141 		TRACE("send failed: %x\n", sccb.hdr.response_code);
142 		rc = -EIO;
143 		goto out;
144 	}
145 
146 	switch (sccb.evbuf.event_status) {
147 		case 0:
148 			rc = sccb.evbuf.blk_cnt;
149 			break;
150 		default:
151 			pr_err("SCLP error: %x\n",
152 			       sccb.evbuf.event_status);
153 			rc = -EIO;
154 			goto out;
155 	}
156 	TRACE("%i blocks\n", rc);
157 out:
158 	mutex_unlock(&sdias_mutex);
159 	return rc;
160 }
161 
162 /*
163  * Copy from HSA to absolute storage (not reentrant):
164  *
165  * @dest     : Address of buffer where data should be copied
166  * @start_blk: Start Block (beginning with 1)
167  * @nr_blks  : Number of 4K blocks to copy
168  *
169  * Return Value: 0 : Requested 'number' of blocks of data copied
170  *		 <0: ERROR - negative event status
171  */
172 int sclp_sdias_copy(void *dest, int start_blk, int nr_blks)
173 {
174 	struct sclp_req request;
175 	int rc;
176 
177 	mutex_lock(&sdias_mutex);
178 
179 	memset(&sccb, 0, sizeof(sccb));
180 	memset(&request, 0, sizeof(request));
181 
182 	sccb.hdr.length = sizeof(sccb);
183 	sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
184 	sccb.evbuf.hdr.type = EVTYP_SDIAS;
185 	sccb.evbuf.hdr.flags = 0;
186 	sccb.evbuf.event_qual = EQ_STORE_DATA;
187 	sccb.evbuf.data_id = DI_FCP_DUMP;
188 	sccb.evbuf.event_id = 4712;
189 #ifdef __s390x__
190 	sccb.evbuf.asa_size = ASA_SIZE_64;
191 #else
192 	sccb.evbuf.asa_size = ASA_SIZE_32;
193 #endif
194 	sccb.evbuf.event_status = 0;
195 	sccb.evbuf.blk_cnt = nr_blks;
196 	sccb.evbuf.asa = (unsigned long)dest;
197 	sccb.evbuf.fbn = start_blk;
198 	sccb.evbuf.lbn = 0;
199 	sccb.evbuf.dbs = 1;
200 
201 	request.sccb	 = &sccb;
202 	request.command  = SCLP_CMDW_WRITE_EVENT_DATA;
203 	request.status	 = SCLP_REQ_FILLED;
204 	request.callback = sdias_callback;
205 
206 	rc = sdias_sclp_send(&request);
207 	if (rc) {
208 		pr_err("sclp_send failed: %x\n", rc);
209 		goto out;
210 	}
211 	if (sccb.hdr.response_code != 0x0020) {
212 		TRACE("copy failed: %x\n", sccb.hdr.response_code);
213 		rc = -EIO;
214 		goto out;
215 	}
216 
217 	switch (sccb.evbuf.event_status) {
218 		case EVSTATE_ALL_STORED:
219 			TRACE("all stored\n");
220 		case EVSTATE_PART_STORED:
221 			TRACE("part stored: %i\n", sccb.evbuf.blk_cnt);
222 			break;
223 		case EVSTATE_NO_DATA:
224 			TRACE("no data\n");
225 		default:
226 			pr_err("Error from SCLP while copying hsa. "
227 			       "Event status = %x\n",
228 			       sccb.evbuf.event_status);
229 			rc = -EIO;
230 	}
231 out:
232 	mutex_unlock(&sdias_mutex);
233 	return rc;
234 }
235 
236 int __init sclp_sdias_init(void)
237 {
238 	int rc;
239 
240 	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
241 		return 0;
242 	sdias_dbf = debug_register("dump_sdias", 4, 1, 4 * sizeof(long));
243 	debug_register_view(sdias_dbf, &debug_sprintf_view);
244 	debug_set_level(sdias_dbf, 6);
245 	rc = sclp_register(&sclp_sdias_register);
246 	if (rc)
247 		return rc;
248 	init_waitqueue_head(&sdias_wq);
249 	TRACE("init done\n");
250 	return 0;
251 }
252 
253 void __exit sclp_sdias_exit(void)
254 {
255 	debug_unregister(sdias_dbf);
256 	sclp_unregister(&sclp_sdias_register);
257 }
258