kernel/drivers/s390/char/sclp_sdias.c

   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
  26 static struct debug_info *sdias_dbf;
  27
  28 static struct sclp_register sclp_sdias_register = {
  29         .send_mask = EVTYP_SDIAS_MASK,
  30 };
  31
  32 static struct sdias_sccb sccb __attribute__((aligned(4096)));
  33 static struct sdias_evbuf sdias_evbuf;
  34
  35 static DECLARE_COMPLETION(evbuf_accepted);
  36 static DECLARE_COMPLETION(evbuf_done);
  37 static DEFINE_MUTEX(sdias_mutex);
  38
  39 /*
  40  * Called by SCLP base when read event data has been completed (async mode only)
  41  */
  42 static 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  */
  53 static void sdias_callback(struct sclp_req *request, void *data)
  54 {
  55         complete(&evbuf_accepted);
  56         TRACE("callback done\n");
  57 }
  58
  59 static 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  */
 105 int 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);
 149 out:
 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  */
 164 int 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         }
 220 out:
 221         mutex_unlock(&sdias_mutex);
 222         return rc;
 223 }
 224
 225 static 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
 239 static 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
 247 static 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
 255 int __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;
 268 out:
 269         TRACE("init done\n");
 270         return 0;
 271 }
 272
 273 void __exit sclp_sdias_exit(void)
 274 {
 275         debug_unregister(sdias_dbf);
 276         sclp_unregister(&sclp_sdias_register);
 277 }