1 /* 2 * S390 virtio-ccw loading program 3 * 4 * Copyright (c) 2013 Alexander Graf <agraf@suse.de> 5 * 6 * This work is licensed under the terms of the GNU GPL, version 2 or (at 7 * your option) any later version. See the COPYING file in the top-level 8 * directory. 9 */ 10 11 #include <stdlib.h> 12 #include <string.h> 13 #include <stdio.h> 14 #include "helper.h" 15 #include "s390-arch.h" 16 #include "s390-ccw.h" 17 #include "cio.h" 18 #include "virtio.h" 19 #include "virtio-scsi.h" 20 #include "dasd-ipl.h" 21 22 static SubChannelId blk_schid = { .one = 1 }; 23 static char loadparm_str[LOADPARM_LEN + 1]; 24 QemuIplParameters qipl; 25 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE))); 26 static bool have_iplb; 27 static uint16_t cutype; 28 LowCore *lowcore; /* Yes, this *is* a pointer to address 0 */ 29 30 #define LOADPARM_PROMPT "PROMPT " 31 #define LOADPARM_EMPTY " " 32 #define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL) 33 34 /* 35 * Principles of Operations (SA22-7832-09) chapter 17 requires that 36 * a subsystem-identification is at 184-187 and bytes 188-191 are zero 37 * after list-directed-IPL and ccw-IPL. 38 */ 39 void write_subsystem_identification(void) 40 { 41 if (cutype == CU_TYPE_VIRTIO && virtio_get_device_type() == VIRTIO_ID_NET) { 42 lowcore->subchannel_id = net_schid.sch_id; 43 lowcore->subchannel_nr = net_schid.sch_no; 44 } else { 45 lowcore->subchannel_id = blk_schid.sch_id; 46 lowcore->subchannel_nr = blk_schid.sch_no; 47 } 48 lowcore->io_int_parm = 0; 49 } 50 51 void write_iplb_location(void) 52 { 53 if (cutype == CU_TYPE_VIRTIO && virtio_get_device_type() != VIRTIO_ID_NET) { 54 lowcore->ptr_iplb = ptr2u32(&iplb); 55 } 56 } 57 58 unsigned int get_loadparm_index(void) 59 { 60 return atoi(loadparm_str); 61 } 62 63 static int is_dev_possibly_bootable(int dev_no, int sch_no) 64 { 65 bool is_virtio; 66 Schib schib; 67 int r; 68 69 blk_schid.sch_no = sch_no; 70 r = stsch_err(blk_schid, &schib); 71 if (r == 3 || r == -EIO) { 72 return -ENODEV; 73 } 74 if (!schib.pmcw.dnv) { 75 return false; 76 } 77 78 enable_subchannel(blk_schid); 79 cutype = cu_type(blk_schid); 80 if (cutype == CU_TYPE_UNKNOWN) { 81 return -EIO; 82 } 83 84 /* 85 * Note: we always have to run virtio_is_supported() here to make 86 * sure that the vdev.senseid data gets pre-initialized correctly 87 */ 88 is_virtio = virtio_is_supported(blk_schid); 89 90 /* No specific devno given, just return whether the device is possibly bootable */ 91 if (dev_no < 0) { 92 switch (cutype) { 93 case CU_TYPE_VIRTIO: 94 if (is_virtio) { 95 /* 96 * Skip net devices since no IPLB is created and therefore 97 * no network bootloader has been loaded 98 */ 99 if (virtio_get_device_type() != VIRTIO_ID_NET) { 100 return true; 101 } 102 } 103 return false; 104 case CU_TYPE_DASD_3990: 105 case CU_TYPE_DASD_2107: 106 return true; 107 default: 108 return false; 109 } 110 } 111 112 /* Caller asked for a specific devno */ 113 if (schib.pmcw.dev == dev_no) { 114 return true; 115 } 116 117 return false; 118 } 119 120 /* 121 * Find the subchannel connected to the given device (dev_no) and fill in the 122 * subchannel information block (schib) with the connected subchannel's info. 123 * NOTE: The global variable blk_schid is updated to contain the subchannel 124 * information. 125 * 126 * If the caller gives dev_no=-1 then the user did not specify a boot device. 127 * In this case we'll just use the first potentially bootable device we find. 128 */ 129 static bool find_subch(int dev_no) 130 { 131 int i, r; 132 133 for (i = 0; i < 0x10000; i++) { 134 r = is_dev_possibly_bootable(dev_no, i); 135 if (r < 0) { 136 break; 137 } 138 if (r == true) { 139 return true; 140 } 141 } 142 143 return false; 144 } 145 146 static void menu_setup(void) 147 { 148 if (memcmp(loadparm_str, LOADPARM_PROMPT, LOADPARM_LEN) == 0) { 149 menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0); 150 return; 151 } 152 153 /* If loadparm was set to any other value, then do not enable menu */ 154 if (memcmp(loadparm_str, LOADPARM_EMPTY, LOADPARM_LEN) != 0) { 155 return; 156 } 157 158 switch (iplb.pbt) { 159 case S390_IPL_TYPE_CCW: 160 case S390_IPL_TYPE_QEMU_SCSI: 161 menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK, 162 qipl.boot_menu_timeout); 163 return; 164 } 165 } 166 167 /* 168 * Initialize the channel I/O subsystem so we can talk to our ipl/boot device. 169 */ 170 static void css_setup(void) 171 { 172 /* 173 * Unconditionally enable mss support. In every sane configuration this 174 * will succeed; and even if it doesn't, stsch_err() can handle it. 175 */ 176 enable_mss_facility(); 177 } 178 179 /* 180 * Collect various pieces of information from the hypervisor/hardware that 181 * we'll use to determine exactly how we'll boot. 182 */ 183 static void boot_setup(void) 184 { 185 char lpmsg[] = "LOADPARM=[________]\n"; 186 have_iplb = store_iplb(&iplb); 187 188 if (memcmp(iplb.loadparm, NO_LOADPARM, LOADPARM_LEN) != 0) { 189 ebcdic_to_ascii((char *) iplb.loadparm, loadparm_str, LOADPARM_LEN); 190 } else { 191 sclp_get_loadparm_ascii(loadparm_str); 192 } 193 194 memcpy(lpmsg + 10, loadparm_str, 8); 195 puts(lpmsg); 196 197 /* 198 * Clear out any potential S390EP magic (see jump_to_low_kernel()), 199 * so we don't taint our decision-making process during a reboot. 200 */ 201 memset((char *)S390EP, 0, 6); 202 } 203 204 static bool find_boot_device(void) 205 { 206 VDev *vdev = virtio_get_device(); 207 bool found = false; 208 209 switch (iplb.pbt) { 210 case S390_IPL_TYPE_CCW: 211 debug_print_int("device no. ", iplb.ccw.devno); 212 blk_schid.ssid = iplb.ccw.ssid & 0x3; 213 debug_print_int("ssid ", blk_schid.ssid); 214 found = find_subch(iplb.ccw.devno); 215 break; 216 case S390_IPL_TYPE_QEMU_SCSI: 217 vdev->scsi_device_selected = true; 218 vdev->selected_scsi_device.channel = iplb.scsi.channel; 219 vdev->selected_scsi_device.target = iplb.scsi.target; 220 vdev->selected_scsi_device.lun = iplb.scsi.lun; 221 blk_schid.ssid = iplb.scsi.ssid & 0x3; 222 found = find_subch(iplb.scsi.devno); 223 break; 224 default: 225 puts("Unsupported IPLB"); 226 } 227 228 return found; 229 } 230 231 static int virtio_setup(void) 232 { 233 VDev *vdev = virtio_get_device(); 234 QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS; 235 int ret; 236 237 memcpy(&qipl, early_qipl, sizeof(QemuIplParameters)); 238 239 if (have_iplb) { 240 menu_setup(); 241 } 242 243 switch (vdev->senseid.cu_model) { 244 case VIRTIO_ID_NET: 245 puts("Network boot device detected"); 246 return 0; 247 case VIRTIO_ID_BLOCK: 248 ret = virtio_blk_setup_device(blk_schid); 249 break; 250 case VIRTIO_ID_SCSI: 251 ret = virtio_scsi_setup_device(blk_schid); 252 break; 253 default: 254 puts("\n! No IPL device available !\n"); 255 return -1; 256 } 257 258 if (!ret && !virtio_ipl_disk_is_valid()) { 259 puts("No valid IPL device detected"); 260 return -ENODEV; 261 } 262 263 return ret; 264 } 265 266 static void ipl_boot_device(void) 267 { 268 switch (cutype) { 269 case CU_TYPE_DASD_3990: 270 case CU_TYPE_DASD_2107: 271 dasd_ipl(blk_schid, cutype); 272 break; 273 case CU_TYPE_VIRTIO: 274 if (virtio_setup()) { 275 return; /* Only returns in case of errors */ 276 } 277 zipl_load(); 278 break; 279 default: 280 printf("Attempting to boot from unexpected device type 0x%X\n", cutype); 281 } 282 } 283 284 /* 285 * No boot device has been specified, so we have to scan through the 286 * channels to find one. 287 */ 288 static void probe_boot_device(void) 289 { 290 int ssid, sch_no, ret; 291 292 for (ssid = 0; ssid < 0x3; ssid++) { 293 blk_schid.ssid = ssid; 294 for (sch_no = 0; sch_no < 0x10000; sch_no++) { 295 ret = is_dev_possibly_bootable(-1, sch_no); 296 if (ret < 0) { 297 break; 298 } 299 if (ret == true) { 300 ipl_boot_device(); /* Only returns if unsuccessful */ 301 } 302 } 303 } 304 305 puts("Could not find a suitable boot device (none specified)"); 306 } 307 308 void main(void) 309 { 310 sclp_setup(); 311 css_setup(); 312 boot_setup(); 313 if (have_iplb && find_boot_device()) { 314 ipl_boot_device(); 315 } else { 316 probe_boot_device(); 317 } 318 319 panic("Failed to IPL. Halting..."); 320 } 321