xref: /openbmc/qemu/pc-bios/s390-ccw/main.c (revision 56c4bfb3)
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 
13 struct subchannel_id blk_schid;
14 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
15 uint64_t boot_value;
16 
17 void virtio_panic(const char *string)
18 {
19     sclp_print(string);
20     disabled_wait();
21     while (1) { }
22 }
23 
24 static void virtio_setup(uint64_t dev_info)
25 {
26     struct schib schib;
27     int i;
28     int r;
29     bool found = false;
30     bool check_devno = false;
31     uint16_t dev_no = -1;
32     blk_schid.one = 1;
33 
34     if (dev_info != -1) {
35         check_devno = true;
36         dev_no = dev_info & 0xffff;
37         debug_print_int("device no. ", dev_no);
38         blk_schid.ssid = (dev_info >> 16) & 0x3;
39         if (blk_schid.ssid != 0) {
40             debug_print_int("ssid ", blk_schid.ssid);
41             if (enable_mss_facility() != 0) {
42                 virtio_panic("Failed to enable mss facility\n");
43             }
44         }
45     }
46 
47     for (i = 0; i < 0x10000; i++) {
48         blk_schid.sch_no = i;
49         r = stsch_err(blk_schid, &schib);
50         if (r == 3) {
51             break;
52         }
53         if (schib.pmcw.dnv) {
54             if (!check_devno || (schib.pmcw.dev == dev_no)) {
55                 if (virtio_is_blk(blk_schid)) {
56                     found = true;
57                     break;
58                 }
59             }
60         }
61     }
62 
63     if (!found) {
64         virtio_panic("No virtio-blk device found!\n");
65     }
66 
67     virtio_setup_block(blk_schid);
68 }
69 
70 int main(void)
71 {
72     sclp_setup();
73     debug_print_int("boot reg[7] ", boot_value);
74     virtio_setup(boot_value);
75 
76     if (zipl_load() < 0)
77         sclp_print("Failed to load OS from hard disk\n");
78     disabled_wait();
79     while (1) { }
80 }
81