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 <asm/ctl_reg.h>
  11 #include <asm/sclp.h>
  12 #include <asm/ipl.h>
  13 #include "sclp_sdias.h"
  14 #include "sclp.h"
  15
  16 #define SCLP_CMDW_READ_SCP_INFO         0x00020001
  17 #define SCLP_CMDW_READ_SCP_INFO_FORCED  0x00120001
  18
  19 struct read_info_sccb {
  20         struct  sccb_header header;     /* 0-7 */
  21         u16     rnmax;                  /* 8-9 */
  22         u8      rnsize;                 /* 10 */
  23         u8      _reserved0[24 - 11];    /* 11-15 */
  24         u8      loadparm[8];            /* 24-31 */
  25         u8      _reserved1[48 - 32];    /* 32-47 */
  26         u64     facilities;             /* 48-55 */
  27         u8      _reserved2[84 - 56];    /* 56-83 */
  28         u8      fac84;                  /* 84 */
  29         u8      fac85;                  /* 85 */
  30         u8      _reserved3[91 - 86];    /* 86-90 */
  31         u8      flags;                  /* 91 */
  32         u8      _reserved4[100 - 92];   /* 92-99 */
  33         u32     rnsize2;                /* 100-103 */
  34         u64     rnmax2;                 /* 104-111 */
  35         u8      _reserved5[4096 - 112]; /* 112-4095 */
  36 } __packed __aligned(PAGE_SIZE);
  37
  38 static __initdata struct init_sccb early_event_mask_sccb __aligned(PAGE_SIZE);
  39 static __initdata struct read_info_sccb early_read_info_sccb;
  40 static __initdata char sccb_early[PAGE_SIZE] __aligned(PAGE_SIZE);
  41 static unsigned long sclp_hsa_size;
  42
  43 __initdata int sclp_early_read_info_sccb_valid;
  44 u64 sclp_facilities;
  45 u8 sclp_fac84;
  46 unsigned long long sclp_rzm;
  47 unsigned long long sclp_rnmax;
  48
  49 static int __init sclp_cmd_sync_early(sclp_cmdw_t cmd, void *sccb)
  50 {
  51         int rc;
  52
  53         __ctl_set_bit(0, 9);
  54         rc = sclp_service_call(cmd, sccb);
  55         if (rc)
  56                 goto out;
  57         __load_psw_mask(PSW_DEFAULT_KEY | PSW_MASK_BASE | PSW_MASK_EA |
  58                         PSW_MASK_BA | PSW_MASK_EXT | PSW_MASK_WAIT);
  59         local_irq_disable();
  60 out:
  61         /* Contents of the sccb might have changed. */
  62         barrier();
  63         __ctl_clear_bit(0, 9);
  64         return rc;
  65 }
  66
  67 static void __init sclp_read_info_early(void)
  68 {
  69         int rc;
  70         int i;
  71         struct read_info_sccb *sccb;
  72         sclp_cmdw_t commands[] = {SCLP_CMDW_READ_SCP_INFO_FORCED,
  73                                   SCLP_CMDW_READ_SCP_INFO};
  74
  75         sccb = &early_read_info_sccb;
  76         for (i = 0; i < ARRAY_SIZE(commands); i++) {
  77                 do {
  78                         memset(sccb, 0, sizeof(*sccb));
  79                         sccb->header.length = sizeof(*sccb);
  80                         sccb->header.function_code = 0x80;
  81                         sccb->header.control_mask[2] = 0x80;
  82                         rc = sclp_cmd_sync_early(commands[i], sccb);
  83                 } while (rc == -EBUSY);
  84
  85                 if (rc)
  86                         break;
  87                 if (sccb->header.response_code == 0x10) {
  88                         sclp_early_read_info_sccb_valid = 1;
  89                         break;
  90                 }
  91                 if (sccb->header.response_code != 0x1f0)
  92                         break;
  93         }
  94 }
  95
  96 static void __init sclp_facilities_detect(void)
  97 {
  98         struct read_info_sccb *sccb;
  99
 100         sclp_read_info_early();
 101         if (!sclp_early_read_info_sccb_valid)
 102                 return;
 103
 104         sccb = &early_read_info_sccb;
 105         sclp_facilities = sccb->facilities;
 106         sclp_fac84 = sccb->fac84;
 107         if (sccb->fac85 & 0x02)
 108                 S390_lowcore.machine_flags |= MACHINE_FLAG_ESOP;
 109         sclp_rnmax = sccb->rnmax ? sccb->rnmax : sccb->rnmax2;
 110         sclp_rzm = sccb->rnsize ? sccb->rnsize : sccb->rnsize2;
 111         sclp_rzm <<= 20;
 112 }
 113
 114 bool __init sclp_has_linemode(void)
 115 {
 116         struct init_sccb *sccb = &early_event_mask_sccb;
 117
 118         if (sccb->header.response_code != 0x20)
 119                 return 0;
 120         if (!(sccb->sclp_send_mask & (EVTYP_OPCMD_MASK | EVTYP_PMSGCMD_MASK)))
 121                 return 0;
 122         if (!(sccb->sclp_receive_mask & (EVTYP_MSG_MASK | EVTYP_PMSGCMD_MASK)))
 123                 return 0;
 124         return 1;
 125 }
 126
 127 bool __init sclp_has_vt220(void)
 128 {
 129         struct init_sccb *sccb = &early_event_mask_sccb;
 130
 131         if (sccb->header.response_code != 0x20)
 132                 return 0;
 133         if (sccb->sclp_send_mask & EVTYP_VT220MSG_MASK)
 134                 return 1;
 135         return 0;
 136 }
 137
 138 unsigned long long sclp_get_rnmax(void)
 139 {
 140         return sclp_rnmax;
 141 }
 142
 143 unsigned long long sclp_get_rzm(void)
 144 {
 145         return sclp_rzm;
 146 }
 147
 148 /*
 149  * This function will be called after sclp_facilities_detect(), which gets
 150  * called from early.c code. Therefore the sccb should have valid contents.
 151  */
 152 void __init sclp_get_ipl_info(struct sclp_ipl_info *info)
 153 {
 154         struct read_info_sccb *sccb;
 155
 156         if (!sclp_early_read_info_sccb_valid)
 157                 return;
 158         sccb = &early_read_info_sccb;
 159         info->is_valid = 1;
 160         if (sccb->flags & 0x2)
 161                 info->has_dump = 1;
 162         memcpy(&info->loadparm, &sccb->loadparm, LOADPARM_LEN);
 163 }
 164
 165 static int __init sclp_cmd_early(sclp_cmdw_t cmd, void *sccb)
 166 {
 167         int rc;
 168
 169         do {
 170                 rc = sclp_cmd_sync_early(cmd, sccb);
 171         } while (rc == -EBUSY);
 172
 173         if (rc)
 174                 return -EIO;
 175         if (((struct sccb_header *) sccb)->response_code != 0x0020)
 176                 return -EIO;
 177         return 0;
 178 }
 179
 180 static void __init sccb_init_eq_size(struct sdias_sccb *sccb)
 181 {
 182         memset(sccb, 0, sizeof(*sccb));
 183
 184         sccb->hdr.length = sizeof(*sccb);
 185         sccb->evbuf.hdr.length = sizeof(struct sdias_evbuf);
 186         sccb->evbuf.hdr.type = EVTYP_SDIAS;
 187         sccb->evbuf.event_qual = SDIAS_EQ_SIZE;
 188         sccb->evbuf.data_id = SDIAS_DI_FCP_DUMP;
 189         sccb->evbuf.event_id = 4712;
 190         sccb->evbuf.dbs = 1;
 191 }
 192
 193 static int __init sclp_set_event_mask(unsigned long receive_mask,
 194                                       unsigned long send_mask)
 195 {
 196         struct init_sccb *sccb = (void *) &sccb_early;
 197
 198         memset(sccb, 0, sizeof(*sccb));
 199         sccb->header.length = sizeof(*sccb);
 200         sccb->mask_length = sizeof(sccb_mask_t);
 201         sccb->receive_mask = receive_mask;
 202         sccb->send_mask = send_mask;
 203         return sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_MASK, sccb);
 204 }
 205
 206 static long __init sclp_hsa_size_init(void)
 207 {
 208         struct sdias_sccb *sccb = (void *) &sccb_early;
 209
 210         sccb_init_eq_size(sccb);
 211         if (sclp_cmd_early(SCLP_CMDW_WRITE_EVENT_DATA, sccb))
 212                 return -EIO;
 213         if (sccb->evbuf.blk_cnt != 0)
 214                 return (sccb->evbuf.blk_cnt - 1) * PAGE_SIZE;
 215         return 0;
 216 }
 217
 218 static long __init sclp_hsa_copy_wait(void)
 219 {
 220         struct sccb_header *sccb = (void *) &sccb_early;
 221
 222         memset(sccb, 0, PAGE_SIZE);
 223         sccb->length = PAGE_SIZE;
 224         if (sclp_cmd_early(SCLP_CMDW_READ_EVENT_DATA, sccb))
 225                 return -EIO;
 226         return (((struct sdias_sccb *) sccb)->evbuf.blk_cnt - 1) * PAGE_SIZE;
 227 }
 228
 229 unsigned long sclp_get_hsa_size(void)
 230 {
 231         return sclp_hsa_size;
 232 }
 233
 234 static void __init sclp_hsa_size_detect(void)
 235 {
 236         long size;
 237
 238         /* First try synchronous interface (LPAR) */
 239         if (sclp_set_event_mask(0, 0x40000010))
 240                 return;
 241         size = sclp_hsa_size_init();
 242         if (size < 0)
 243                 return;
 244         if (size != 0)
 245                 goto out;
 246         /* Then try asynchronous interface (z/VM) */
 247         if (sclp_set_event_mask(0x00000010, 0x40000010))
 248                 return;
 249         size = sclp_hsa_size_init();
 250         if (size < 0)
 251                 return;
 252         size = sclp_hsa_copy_wait();
 253         if (size < 0)
 254                 return;
 255 out:
 256         sclp_hsa_size = size;
 257 }
 258
 259 void __init sclp_early_detect(void)
 260 {
 261         sclp_facilities_detect();
 262         sclp_hsa_size_detect();
 263         sclp_set_event_mask(0, 0);
 264 }