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#define SDIAS_SLEEP_TICKS 50
25
26static struct debug_info *sdias_dbf;
27
28static struct sclp_register sclp_sdias_register = {
29	.send_mask = EVTYP_SDIAS_MASK,
30};
31
32static struct sdias_sccb sccb __attribute__((aligned(4096)));
33static struct sdias_evbuf sdias_evbuf;
34
35static DECLARE_COMPLETION(evbuf_accepted);
36static DECLARE_COMPLETION(evbuf_done);
37static DEFINE_MUTEX(sdias_mutex);
38
39/*
40 * Called by SCLP base when read event data has been completed (async mode only)
41 */
42static void sclp_sdias_receiver_fn(struct evbuf_header *evbuf)
43{
44	memcpy(&sdias_evbuf, evbuf,
45	       min_t(unsigned long, sizeof(sdias_evbuf), evbuf->length));
46	complete(&evbuf_done);
47	TRACE("sclp_sdias_receiver_fn done\n");
48}
49
50/*
51 * Called by SCLP base when sdias event has been accepted
52 */
53static void sdias_callback(struct sclp_req *request, void *data)
54{
55	complete(&evbuf_accepted);
56	TRACE("callback done\n");
57}
58
59static int sdias_sclp_send(struct sclp_req *req)
60{
61	int retries;
62	int rc;
63
64	for (retries = SDIAS_RETRIES; retries; retries--) {
65		TRACE("add request\n");
66		rc = sclp_add_request(req);
67		if (rc) {
68			/* not initiated, wait some time and retry */
69			set_current_state(TASK_INTERRUPTIBLE);
70			TRACE("add request failed: rc = %i\n",rc);
71			schedule_timeout(SDIAS_SLEEP_TICKS);
72			continue;
73		}
74		/* initiated, wait for completion of service call */
75		wait_for_completion(&evbuf_accepted);
76		if (req->status == SCLP_REQ_FAILED) {
77			TRACE("sclp request failed\n");
78			continue;
79		}
80		/* if not accepted, retry */
81		if (!(sccb.evbuf.hdr.flags & 0x80)) {
82			TRACE("sclp request failed: flags=%x\n",
83			      sccb.evbuf.hdr.flags);
84			continue;
85		}
86		/*
87		 * for the sync interface the response is in the initial sccb
88		 */
89		if (!sclp_sdias_register.receiver_fn) {
90			memcpy(&sdias_evbuf, &sccb.evbuf, sizeof(sdias_evbuf));
91			TRACE("sync request done\n");
92			return 0;
93		}
94		/* otherwise we wait for completion */
95		wait_for_completion(&evbuf_done);
96		TRACE("request done\n");
97		return 0;
98	}
99	return -EIO;
100}
101
102/*
103 * Get number of blocks (4K) available in the HSA
104 */
105int sclp_sdias_blk_count(void)
106{
107	struct sclp_req request;
108	int rc;
109
110	mutex_lock(&sdias_mutex);
111
112	memset(&sccb, 0, sizeof(sccb));
113	memset(&request, 0, sizeof(request));
114
115	sccb.hdr.length = sizeof(sccb);
116	sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
117	sccb.evbuf.hdr.type = EVTYP_SDIAS;
118	sccb.evbuf.event_qual = SDIAS_EQ_SIZE;
119	sccb.evbuf.data_id = SDIAS_DI_FCP_DUMP;
120	sccb.evbuf.event_id = 4712;
121	sccb.evbuf.dbs = 1;
122
123	request.sccb = &sccb;
124	request.command = SCLP_CMDW_WRITE_EVENT_DATA;
125	request.status = SCLP_REQ_FILLED;
126	request.callback = sdias_callback;
127
128	rc = sdias_sclp_send(&request);
129	if (rc) {
130		pr_err("sclp_send failed for get_nr_blocks\n");
131		goto out;
132	}
133	if (sccb.hdr.response_code != 0x0020) {
134		TRACE("send failed: %x\n", sccb.hdr.response_code);
135		rc = -EIO;
136		goto out;
137	}
138
139	switch (sdias_evbuf.event_status) {
140		case 0:
141			rc = sdias_evbuf.blk_cnt;
142			break;
143		default:
144			pr_err("SCLP error: %x\n", sdias_evbuf.event_status);
145			rc = -EIO;
146			goto out;
147	}
148	TRACE("%i blocks\n", rc);
149out:
150	mutex_unlock(&sdias_mutex);
151	return rc;
152}
153
154/*
155 * Copy from HSA to absolute storage (not reentrant):
156 *
157 * @dest     : Address of buffer where data should be copied
158 * @start_blk: Start Block (beginning with 1)
159 * @nr_blks  : Number of 4K blocks to copy
160 *
161 * Return Value: 0 : Requested 'number' of blocks of data copied
162 *		 <0: ERROR - negative event status
163 */
164int sclp_sdias_copy(void *dest, int start_blk, int nr_blks)
165{
166	struct sclp_req request;
167	int rc;
168
169	mutex_lock(&sdias_mutex);
170
171	memset(&sccb, 0, sizeof(sccb));
172	memset(&request, 0, sizeof(request));
173
174	sccb.hdr.length = sizeof(sccb);
175	sccb.evbuf.hdr.length = sizeof(struct sdias_evbuf);
176	sccb.evbuf.hdr.type = EVTYP_SDIAS;
177	sccb.evbuf.hdr.flags = 0;
178	sccb.evbuf.event_qual = SDIAS_EQ_STORE_DATA;
179	sccb.evbuf.data_id = SDIAS_DI_FCP_DUMP;
180	sccb.evbuf.event_id = 4712;
181	sccb.evbuf.asa_size = SDIAS_ASA_SIZE_64;
182	sccb.evbuf.event_status = 0;
183	sccb.evbuf.blk_cnt = nr_blks;
184	sccb.evbuf.asa = (unsigned long)dest;
185	sccb.evbuf.fbn = start_blk;
186	sccb.evbuf.lbn = 0;
187	sccb.evbuf.dbs = 1;
188
189	request.sccb	 = &sccb;
190	request.command  = SCLP_CMDW_WRITE_EVENT_DATA;
191	request.status	 = SCLP_REQ_FILLED;
192	request.callback = sdias_callback;
193
194	rc = sdias_sclp_send(&request);
195	if (rc) {
196		pr_err("sclp_send failed: %x\n", rc);
197		goto out;
198	}
199	if (sccb.hdr.response_code != 0x0020) {
200		TRACE("copy failed: %x\n", sccb.hdr.response_code);
201		rc = -EIO;
202		goto out;
203	}
204
205	switch (sdias_evbuf.event_status) {
206	case SDIAS_EVSTATE_ALL_STORED:
207		TRACE("all stored\n");
208		break;
209	case SDIAS_EVSTATE_PART_STORED:
210		TRACE("part stored: %i\n", sdias_evbuf.blk_cnt);
211		break;
212	case SDIAS_EVSTATE_NO_DATA:
213		TRACE("no data\n");
214		/* fall through */
215	default:
216		pr_err("Error from SCLP while copying hsa. Event status = %x\n",
217		       sdias_evbuf.event_status);
218		rc = -EIO;
219	}
220out:
221	mutex_unlock(&sdias_mutex);
222	return rc;
223}
224
225static int __init sclp_sdias_register_check(void)
226{
227	int rc;
228
229	rc = sclp_register(&sclp_sdias_register);
230	if (rc)
231		return rc;
232	if (sclp_sdias_blk_count() == 0) {
233		sclp_unregister(&sclp_sdias_register);
234		return -ENODEV;
235	}
236	return 0;
237}
238
239static int __init sclp_sdias_init_sync(void)
240{
241	TRACE("Try synchronous mode\n");
242	sclp_sdias_register.receive_mask = 0;
243	sclp_sdias_register.receiver_fn = NULL;
244	return sclp_sdias_register_check();
245}
246
247static int __init sclp_sdias_init_async(void)
248{
249	TRACE("Try asynchronous mode\n");
250	sclp_sdias_register.receive_mask = EVTYP_SDIAS_MASK;
251	sclp_sdias_register.receiver_fn = sclp_sdias_receiver_fn;
252	return sclp_sdias_register_check();
253}
254
255int __init sclp_sdias_init(void)
256{
257	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
258		return 0;
259	sdias_dbf = debug_register("dump_sdias", 4, 1, 4 * sizeof(long));
260	debug_register_view(sdias_dbf, &debug_sprintf_view);
261	debug_set_level(sdias_dbf, 6);
262	if (sclp_sdias_init_sync() == 0)
263		goto out;
264	if (sclp_sdias_init_async() == 0)
265		goto out;
266	TRACE("init failed\n");
267	return -ENODEV;
268out:
269	TRACE("init done\n");
270	return 0;
271}
272
273void __exit sclp_sdias_exit(void)
274{
275	debug_unregister(sdias_dbf);
276	sclp_unregister(&sclp_sdias_register);
277}
278