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 "s390-ccw.h" 12 #include "virtio.h" 13 14 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE))); 15 static SubChannelId blk_schid = { .one = 1 }; 16 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE))); 17 18 /* 19 * Priniciples of Operations (SA22-7832-09) chapter 17 requires that 20 * a subsystem-identification is at 184-187 and bytes 188-191 are zero 21 * after list-directed-IPL and ccw-IPL. 22 */ 23 void write_subsystem_identification(void) 24 { 25 SubChannelId *schid = (SubChannelId *) 184; 26 uint32_t *zeroes = (uint32_t *) 188; 27 28 *schid = blk_schid; 29 *zeroes = 0; 30 } 31 32 33 void panic(const char *string) 34 { 35 sclp_print(string); 36 disabled_wait(); 37 while (1) { } 38 } 39 40 static bool find_dev(Schib *schib, int dev_no) 41 { 42 int i, r; 43 44 for (i = 0; i < 0x10000; i++) { 45 blk_schid.sch_no = i; 46 r = stsch_err(blk_schid, schib); 47 if ((r == 3) || (r == -EIO)) { 48 break; 49 } 50 if (!schib->pmcw.dnv) { 51 continue; 52 } 53 if (!virtio_is_supported(blk_schid)) { 54 continue; 55 } 56 if ((dev_no < 0) || (schib->pmcw.dev == dev_no)) { 57 return true; 58 } 59 } 60 61 return false; 62 } 63 64 static void virtio_setup(void) 65 { 66 Schib schib; 67 int ssid; 68 bool found = false; 69 uint16_t dev_no; 70 71 /* 72 * We unconditionally enable mss support. In every sane configuration, 73 * this will succeed; and even if it doesn't, stsch_err() can deal 74 * with the consequences. 75 */ 76 enable_mss_facility(); 77 78 if (store_iplb(&iplb)) { 79 switch (iplb.pbt) { 80 case S390_IPL_TYPE_CCW: 81 dev_no = iplb.ccw.devno; 82 debug_print_int("device no. ", dev_no); 83 blk_schid.ssid = iplb.ccw.ssid & 0x3; 84 debug_print_int("ssid ", blk_schid.ssid); 85 found = find_dev(&schib, dev_no); 86 break; 87 case S390_IPL_TYPE_QEMU_SCSI: 88 { 89 VDev *vdev = virtio_get_device(); 90 91 vdev->scsi_device_selected = true; 92 vdev->selected_scsi_device.channel = iplb.scsi.channel; 93 vdev->selected_scsi_device.target = iplb.scsi.target; 94 vdev->selected_scsi_device.lun = iplb.scsi.lun; 95 blk_schid.ssid = iplb.scsi.ssid & 0x3; 96 found = find_dev(&schib, iplb.scsi.devno); 97 break; 98 } 99 default: 100 panic("List-directed IPL not supported yet!\n"); 101 } 102 } else { 103 for (ssid = 0; ssid < 0x3; ssid++) { 104 blk_schid.ssid = ssid; 105 found = find_dev(&schib, -1); 106 if (found) { 107 break; 108 } 109 } 110 } 111 112 IPL_assert(found, "No virtio device found"); 113 114 virtio_setup_device(blk_schid); 115 116 IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected"); 117 } 118 119 int main(void) 120 { 121 sclp_setup(); 122 virtio_setup(); 123 124 zipl_load(); /* no return */ 125 126 panic("Failed to load OS from hard disk\n"); 127 return 0; /* make compiler happy */ 128 } 129