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
  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 }