drivers/s390/char/sclp_early.c

   1 /*
   2  * SCLP early driver
   3  *
   4  * Copyright IBM Corp. 2013
   5  */
   6
   7 #define KMSG_COMPONENT "sclp_early"
   8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
   9
  10 #include <linux/errno.h>
  11 #include <asm/ctl_reg.h>
  12 #include <asm/sclp.h>
  13 #include <asm/ipl.h>
  14 #include "sclp_sdias.h"
  15 #include "sclp.h"
  16
  17 #define SCLP_CMDW_READ_SCP_INFO         0x00020001
  18 #define SCLP_CMDW_READ_SCP_INFO_FORCED  0x00120001
  19
  20 struct read_info_sccb {
  21         struct  sccb_header header;     /* 0-7 */
  22         u16     rnmax;                  /* 8-9 */
  23         u8      rnsize;                 /* 10 */
  24         u8      _pad_11[16 - 11];       /* 11-15 */
  25         u16     ncpurl;                 /* 16-17 */
  26         u16     cpuoff;                 /* 18-19 */
  27         u8      _pad_20[24 - 20];       /* 20-23 */
  28         u8      loadparm[8];            /* 24-31 */
  29         u8      _pad_32[42 - 32];       /* 32-41 */
  30         u8      fac42;                  /* 42 */
  31         u8      fac43;                  /* 43 */
  32         u8      _pad_44[48 - 44];       /* 44-47 */
  33         u64     facilities;             /* 48-55 */
  34         u8      _pad_56[66 - 56];       /* 56-65 */
  35         u8      fac66;                  /* 66 */
  36         u8      _pad_67[76 - 67];       /* 67-83 */
  37         u32     ibc;                    /* 76-79 */
  38         u8      _pad80[84 - 80];        /* 80-83 */
  39         u8      fac84;                  /* 84 */
  40         u8      fac85;                  /* 85 */
  41         u8      _pad_86[91 - 86];       /* 86-90 */
  42         u8      flags;                  /* 91 */
  43         u8      _pad_92[100 - 92];      /* 92-99 */
  44         u32     rnsize2;                /* 100-103 */
  45         u64     rnmax2;                 /* 104-111 */
  46         u8      _pad_112[120 - 112];    /* 112-119 */
  47         u16     hcpua;                  /* 120-121 */
  48         u8      _pad_122[4096 - 122];   /* 122-4095 */
  49 } __packed __aligned(PAGE_SIZE);
  50
  51 static char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE) __initdata;
  52 static struct sclp_ipl_info sclp_ipl_info;
  53
  54 struct sclp_info sclp;
  55 EXPORT_SYMBOL(sclp);
  56
  57 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
  58 {
  59         int rc;
  60
  61         __ctl_set_bit(0, 9);
  62         rc = sclp_service_call(cmd, sccb);
  63         if (rc)
  64                 goto out;
  65         __load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
  66                         PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
  67         local_irq_disable();
  68 out:
  69         /* Contents of the sccb might have changed. */
  70         barrier();
  71         __ctl_clear_bit(0, 9);
  72         return rc;
  73 }
  74
  75 static int __init sclp_read_info_early(struct read_info_sccb *sccb)
  76 {
  77         int rc, i;
  78         sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
  79                                   SCLP_CMDW_READ_SCP_INFO};
  80
  81         for (i = 0; i < ARRAY_SIZE(commands); i++) {
  82                 do {
  83                         memset(sccb, 0, sizeof(*sccb));
  84                         sccb->header.length = sizeof(*sccb);
  85                         sccb->header.function_code = 0x80;
  86                         sccb->header.control_mask[2] = 0x80;
  87                         rc = sclp_cmd_sync_early(commands[i], sccb);
  88                 } while (rc == -EBUSY);
  89
  90                 if (rc)
  91                         break;
  92                 if (sccb->header.response_code == 0x10)
  93                         return 0;
  94                 if (sccb->header.response_code != 0x1f0)
  95                         break;
  96         }
  97         return -EIO;
  98 }
  99
 100 static void __init sclp_facilities_detect(struct read_info_sccb *sccb)
 101 {
 102         struct sclp_core_entry *cpue;
 103         u16 boot_cpu_address, cpu;
 104
 105         if (sclp_read_info_early(sccb))
 106                 return;
 107
 108         sclp.facilities = sccb->facilities;
 109         sclp.has_sprp = !!(sccb->fac84 & 0x02);
 110         sclp.has_core_type = !!(sccb->fac84 & 0x01);
 111         if (sccb->fac85 & 0x02)
 112                 S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
 113         sclp.rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
 114         sclp.rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
 115         sclp.rzm <<= 20;
 116         sclp.ibc = sccb->ibc;
 117
 118         if (!sccb->hcpua) {
 119                 if (MACHINE_IS_VM)
 120                         sclp.max_cores = 64;
 121                 else
 122                         sclp.max_cores = sccb->ncpurl;
 123         } else {
 124                 sclp.max_cores = sccb->hcpua + 1;
 125         }
 126
 127         boot_cpu_address = stap();
 128         cpue = (void *)sccb + sccb->cpuoff;
 129         for (cpu = 0; cpu < sccb->ncpurl; cpue++, cpu++) {
 130                 if (boot_cpu_address != cpue->core_id)
 131                         continue;
 132                 sclp.has_siif = cpue->siif;
 133                 sclp.has_sigpif = cpue->sigpif;
 134                 break;
 135         }
 136
 137         /* Save IPL information */
 138         sclp_ipl_info.is_valid = 1;
 139         if (sccb->flags & 0x2)
 140                 sclp_ipl_info.has_dump = 1;
 141         memcpy(&sclp_ipl_info.loadparm, &sccb->loadparm, LOADPARM_LEN);
 142
 143         sclp.mtid = (sccb->fac42 & 0x80) ? (sccb->fac42 & 31) : 0;
 144         sclp.mtid_cp = (sccb->fac42 & 0x80) ? (sccb->fac43 & 31) : 0;
 145         sclp.mtid_prev = (sccb->fac42 & 0x80) ? (sccb->fac66 & 31) : 0;
 146 }
 147
 148 /*
 149  * This function will be called after sclp_facilities_detect(), which gets
 150  * called from early.c code. The sclp_facilities_detect() function retrieves
 151  * and saves the IPL information.
 152  */
 153 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
 154 {
 155         *info = sclp_ipl_info;
 156 }
 157
 158 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
 159 {
 160         int rc;
 161
 162         do {
 163                 rc = sclp_cmd_sync_early(cmd, sccb);
 164         } while (rc == -EBUSY);
 165
 166         if (rc)
 167                 return -EIO;
 168         if (((struct sccb_header *) sccb)->response_code != 0x0020)
 169                 return -EIO;
 170         return 0;
 171 }
 172
 173 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
 174 {
 175         memset(sccb, 0, sizeof(*sccb));
 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.event_qual = SDIAS_EQ_SIZE;
 181         sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
 182         sccb->evbuf.event_id = 4712;
 183         sccb->evbuf.dbs = 1;
 184 }
 185
 186 static int __init sclp_set_event_mask(struct init_sccb *sccb,
 187                                       unsigned long receive_mask,
 188                                       unsigned long send_mask)
 189 {
 190         memset(sccb, 0, sizeof(*sccb));
 191         sccb->header.length = sizeof(*sccb);
 192         sccb->mask_length = sizeof(sccb_mask_t);
 193         sccb->receive_mask = receive_mask;
 194         sccb->send_mask = send_mask;
 195         return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
 196 }
 197
 198 static long __init sclp_hsa_size_init(struct sdias_sccb *sccb)
 199 {
 200         sccb_init_eq_size(sccb);
 201         if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
 202                 return -EIO;
 203         if (sccb->evbuf.blk_cnt == 0)
 204                 return 0;
 205         return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
 206 }
 207
 208 static long __init sclp_hsa_copy_wait(struct sccb_header *sccb)
 209 {
 210         memset(sccb, 0, PAGE_SIZE);
 211         sccb->length = PAGE_SIZE;
 212         if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
 213                 return -EIO;
 214         if (((struct sdias_sccb *) sccb)->evbuf.blk_cnt == 0)
 215                 return 0;
 216         return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
 217 }
 218
 219 static void __init sclp_hsa_size_detect(void *sccb)
 220 {
 221         long size;
 222
 223         /* First try synchronous interface (LPAR) */
 224         if (sclp_set_event_mask(sccb, 0, 0x40000010))
 225                 return;
 226         size = sclp_hsa_size_init(sccb);
 227         if (size < 0)
 228                 return;
 229         if (size != 0)
 230                 goto out;
 231         /* Then try asynchronous interface (z/VM) */
 232         if (sclp_set_event_mask(sccb, 0x00000010, 0x40000010))
 233                 return;
 234         size = sclp_hsa_size_init(sccb);
 235         if (size < 0)
 236                 return;
 237         size = sclp_hsa_copy_wait(sccb);
 238         if (size < 0)
 239                 return;
 240 out:
 241         sclp.hsa_size = size;
 242 }
 243
 244 static unsigned int __init sclp_con_check_linemode(struct init_sccb *sccb)
 245 {
 246         if (!(sccb->sclp_send_mask & EVTYP_OPCMD_MASK))
 247                 return 0;
 248         if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
 249                 return 0;
 250         return 1;
 251 }
 252
 253 static void __init sclp_console_detect(struct init_sccb *sccb)
 254 {
 255         if (sccb->header.response_code != 0x20)
 256                 return;
 257
 258         if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
 259                 sclp.has_vt220 = 1;
 260
 261         if (sclp_con_check_linemode(sccb))
 262                 sclp.has_linemode = 1;
 263 }
 264
 265 void __init sclp_early_detect(void)
 266 {
 267         void *sccb = &sccb_early;
 268
 269         sclp_facilities_detect(sccb);
 270         sclp_hsa_size_detect(sccb);
 271
 272         /* Turn off SCLP event notifications.  Also save remote masks in the
 273          * sccb.  These are sufficient to detect sclp console capabilities.
 274          */
 275         sclp_set_event_mask(sccb, 0, 0);
 276         sclp_console_detect(sccb);
 277 }