LXR linux/drivers/s390/char/sclp

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * SCLP "store data in absolute storage"
   4 *
   5 * Copyright IBM Corp. 2003, 2013
   6 * Author(s): Michael Holzheu
   7 */
   8
   9#define KMSG_COMPONENT "sclp_sdias"
  10#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
  11
  12#include <linux/completion.h>
  13#include <linux/sched.h>
  14#include <asm/sclp.h>
  15#include <asm/debug.h>
  16#include <asm/ipl.h>
  17
  18#include "sclp_sdias.h"
  19#include "sclp.h"
  20#include "sclp_rw.h"
  21
  22#define TRACE(x...) debug_sprintf_event(sdias_dbf, 1, x)
  23
  24#define SDIAS_RETRIES 300
  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 *sclp_sdias_sccb;
  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        struct sdias_sccb *sccb = sclp_sdias_sccb;
  62        int retries;
  63        int rc;
  64
  65        for (retries = SDIAS_RETRIES; retries; retries--) {
  66                TRACE("add request\n");
  67                rc = sclp_add_request(req);
  68                if (rc) {
  69                        /* not initiated, wait some time and retry */
  70                        set_current_state(TASK_INTERRUPTIBLE);
  71                        TRACE("add request failed: rc = %i\n",rc);
  72                        schedule_timeout(msecs_to_jiffies(500));
  73                        continue;
  74                }
  75                /* initiated, wait for completion of service call */
  76                wait_for_completion(&evbuf_accepted);
  77                if (req->status == SCLP_REQ_FAILED) {
  78                        TRACE("sclp request failed\n");
  79                        continue;
  80                }
  81                /* if not accepted, retry */
  82                if (!(sccb->evbuf.hdr.flags & 0x80)) {
  83                        TRACE("sclp request failed: flags=%x\n",
  84                              sccb->evbuf.hdr.flags);
  85                        continue;
  86                }
  87                /*
  88                 * for the sync interface the response is in the initial sccb
  89                 */
  90                if (!sclp_sdias_register.receiver_fn) {
  91                        memcpy(&sdias_evbuf, &sccb->evbuf, sizeof(sdias_evbuf));
  92                        TRACE("sync request done\n");
  93                        return 0;
  94                }
  95                /* otherwise we wait for completion */
  96                wait_for_completion(&evbuf_done);
  97                TRACE("request done\n");
  98                return 0;
  99        }
 100        return -EIO;
 101}
 102
 103/*
 104 * Get number of blocks (4K) available in the HSA
 105 */
 106int sclp_sdias_blk_count(void)
 107{
 108        struct sdias_sccb *sccb = sclp_sdias_sccb;
 109        struct sclp_req request;
 110        int rc;
 111
 112        mutex_lock(&sdias_mutex);
 113
 114        memset(sccb, 0, sizeof(*sccb));
 115        memset(&request, 0, sizeof(request));
 116
 117        sccb->hdr.length = sizeof(*sccb);
 118        sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
 119        sccb->evbuf.hdr.type = EVTYP_SDIAS;
 120        sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
 121        sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
 122        sccb->evbuf.event_id = 4712;
 123        sccb->evbuf.dbs = 1;
 124
 125        request.sccb = sccb;
 126        request.command = SCLP_CMDW_WRITE_EVENT_DATA;
 127        request.status = SCLP_REQ_FILLED;
 128        request.callback = sdias_callback;
 129
 130        rc = sdias_sclp_send(&request);
 131        if (rc) {
 132                pr_err("sclp_send failed for get_nr_blocks\n");
 133                goto out;
 134        }
 135        if (sccb->hdr.response_code != 0x0020) {
 136                TRACE("send failed: %x\n", sccb->hdr.response_code);
 137                rc = -EIO;
 138                goto out;
 139        }
 140
 141        switch (sdias_evbuf.event_status) {
 142                case 0:
 143                        rc = sdias_evbuf.blk_cnt;
 144                        break;
 145                default:
 146                        pr_err("SCLP error: %x\n", sdias_evbuf.event_status);
 147                        rc = -EIO;
 148                        goto out;
 149        }
 150        TRACE("%i blocks\n", rc);
 151out:
 152        mutex_unlock(&sdias_mutex);
 153        return rc;
 154}
 155
 156/*
 157 * Copy from HSA to absolute storage (not reentrant):
 158 *
 159 * @dest     : Address of buffer where data should be copied
 160 * @start_blk: Start Block (beginning with 1)
 161 * @nr_blks  : Number of 4K blocks to copy
 162 *
 163 * Return Value: 0 : Requested 'number' of blocks of data copied
 164 *               <0: ERROR - negative event status
 165 */
 166int sclp_sdias_copy(void *dest, int start_blk, int nr_blks)
 167{
 168        struct sdias_sccb *sccb = sclp_sdias_sccb;
 169        struct sclp_req request;
 170        int rc;
 171
 172        mutex_lock(&sdias_mutex);
 173
 174        memset(sccb, 0, sizeof(*sccb));
 175        memset(&request, 0, sizeof(request));
 176
 177        sccb->hdr.length = sizeof(*sccb);
 178        sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
 179        sccb->evbuf.hdr.type = EVTYP_SDIAS;
 180        sccb->evbuf.hdr.flags = 0;
 181        sccb->evbuf.event_qual = SDIAS_EQ_STORE_DATA;
 182        sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
 183        sccb->evbuf.event_id = 4712;
 184        sccb->evbuf.asa_size = SDIAS_ASA_SIZE_64;
 185        sccb->evbuf.event_status = 0;
 186        sccb->evbuf.blk_cnt = nr_blks;
 187        sccb->evbuf.asa = (unsigned long)dest;
 188        sccb->evbuf.fbn = start_blk;
 189        sccb->evbuf.lbn = 0;
 190        sccb->evbuf.dbs = 1;
 191
 192        request.sccb     = sccb;
 193        request.command  = SCLP_CMDW_WRITE_EVENT_DATA;
 194        request.status   = SCLP_REQ_FILLED;
 195        request.callback = sdias_callback;
 196
 197        rc = sdias_sclp_send(&request);
 198        if (rc) {
 199                pr_err("sclp_send failed: %x\n", rc);
 200                goto out;
 201        }
 202        if (sccb->hdr.response_code != 0x0020) {
 203                TRACE("copy failed: %x\n", sccb->hdr.response_code);
 204                rc = -EIO;
 205                goto out;
 206        }
 207
 208        switch (sdias_evbuf.event_status) {
 209        case SDIAS_EVSTATE_ALL_STORED:
 210                TRACE("all stored\n");
 211                break;
 212        case SDIAS_EVSTATE_PART_STORED:
 213                TRACE("part stored: %i\n", sdias_evbuf.blk_cnt);
 214                break;
 215        case SDIAS_EVSTATE_NO_DATA:
 216                TRACE("no data\n");
 217                fallthrough;
 218        default:
 219                pr_err("Error from SCLP while copying hsa. Event status = %x\n",
 220                       sdias_evbuf.event_status);
 221                rc = -EIO;
 222        }
 223out:
 224        mutex_unlock(&sdias_mutex);
 225        return rc;
 226}
 227
 228static int __init sclp_sdias_register_check(void)
 229{
 230        int rc;
 231
 232        rc = sclp_register(&sclp_sdias_register);
 233        if (rc)
 234                return rc;
 235        if (sclp_sdias_blk_count() == 0) {
 236                sclp_unregister(&sclp_sdias_register);
 237                return -ENODEV;
 238        }
 239        return 0;
 240}
 241
 242static int __init sclp_sdias_init_sync(void)
 243{
 244        TRACE("Try synchronous mode\n");
 245        sclp_sdias_register.receive_mask = 0;
 246        sclp_sdias_register.receiver_fn = NULL;
 247        return sclp_sdias_register_check();
 248}
 249
 250static int __init sclp_sdias_init_async(void)
 251{
 252        TRACE("Try asynchronous mode\n");
 253        sclp_sdias_register.receive_mask = EVTYP_SDIAS_MASK;
 254        sclp_sdias_register.receiver_fn = sclp_sdias_receiver_fn;
 255        return sclp_sdias_register_check();
 256}
 257
 258int __init sclp_sdias_init(void)
 259{
 260        if (ipl_info.type != IPL_TYPE_FCP_DUMP)
 261                return 0;
 262        sclp_sdias_sccb = (void *) __get_free_page(GFP_KERNEL | GFP_DMA);
 263        BUG_ON(!sclp_sdias_sccb);
 264        sdias_dbf = debug_register("dump_sdias", 4, 1, 4 * sizeof(long));
 265        debug_register_view(sdias_dbf, &debug_sprintf_view);
 266        debug_set_level(sdias_dbf, 6);
 267        if (sclp_sdias_init_sync() == 0)
 268                goto out;
 269        if (sclp_sdias_init_async() == 0)
 270                goto out;
 271        TRACE("init failed\n");
 272        free_page((unsigned long) sclp_sdias_sccb);
 273        return -ENODEV;
 274out:
 275        TRACE("init done\n");
 276        return 0;
 277}
 278
 279void __exit sclp_sdias_exit(void)
 280{
 281        debug_unregister(sdias_dbf);
 282        sclp_unregister(&sclp_sdias_register);
 283}
 284