Merge remote-tracking branch 'remotes/dagrh/tags/pull-virtiofs-20211026' into staging
[qemu.git] / pc-bios / s390-ccw / main.c
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 "libc.h"
12 #include "helper.h"
13 #include "s390-arch.h"
14 #include "s390-ccw.h"
15 #include "cio.h"
16 #include "virtio.h"
17 #include "dasd-ipl.h"
18
19 char stack[PAGE_SIZE * 8] __attribute__((__aligned__(PAGE_SIZE)));
20 static SubChannelId blk_schid = { .one = 1 };
21 static char loadparm_str[LOADPARM_LEN + 1];
22 QemuIplParameters qipl;
23 IplParameterBlock iplb __attribute__((__aligned__(PAGE_SIZE)));
24 static bool have_iplb;
25 static uint16_t cutype;
26 LowCore *lowcore; /* Yes, this *is* a pointer to address 0 */
27
28 #define LOADPARM_PROMPT "PROMPT "
29 #define LOADPARM_EMPTY " "
30 #define BOOT_MENU_FLAG_MASK (QIPL_FLAG_BM_OPTS_CMD | QIPL_FLAG_BM_OPTS_ZIPL)
31
32 /*
33 * Principles of Operations (SA22-7832-09) chapter 17 requires that
34 * a subsystem-identification is at 184-187 and bytes 188-191 are zero
35 * after list-directed-IPL and ccw-IPL.
36 */
37 void write_subsystem_identification(void)
38 {
39 lowcore->subchannel_id = blk_schid.sch_id;
40 lowcore->subchannel_nr = blk_schid.sch_no;
41 lowcore->io_int_parm = 0;
42 }
43
44 void write_iplb_location(void)
45 {
46 if (cutype == CU_TYPE_VIRTIO && virtio_get_device_type() != VIRTIO_ID_NET) {
47 lowcore->ptr_iplb = ptr2u32(&iplb);
48 }
49 }
50
51 unsigned int get_loadparm_index(void)
52 {
53 return atoui(loadparm_str);
54 }
55
56 static int is_dev_possibly_bootable(int dev_no, int sch_no)
57 {
58 bool is_virtio;
59 Schib schib;
60 int r;
61
62 blk_schid.sch_no = sch_no;
63 r = stsch_err(blk_schid, &schib);
64 if (r == 3 || r == -EIO) {
65 return -ENODEV;
66 }
67 if (!schib.pmcw.dnv) {
68 return false;
69 }
70
71 enable_subchannel(blk_schid);
72 cutype = cu_type(blk_schid);
73
74 /*
75 * Note: we always have to run virtio_is_supported() here to make
76 * sure that the vdev.senseid data gets pre-initialized correctly
77 */
78 is_virtio = virtio_is_supported(blk_schid);
79
80 /* No specific devno given, just return whether the device is possibly bootable */
81 if (dev_no < 0) {
82 switch (cutype) {
83 case CU_TYPE_VIRTIO:
84 if (is_virtio) {
85 /*
86 * Skip net devices since no IPLB is created and therefore
87 * no network bootloader has been loaded
88 */
89 if (virtio_get_device_type() != VIRTIO_ID_NET) {
90 return true;
91 }
92 }
93 return false;
94 case CU_TYPE_DASD_3990:
95 case CU_TYPE_DASD_2107:
96 return true;
97 default:
98 return false;
99 }
100 }
101
102 /* Caller asked for a specific devno */
103 if (schib.pmcw.dev == dev_no) {
104 return true;
105 }
106
107 return false;
108 }
109
110 /*
111 * Find the subchannel connected to the given device (dev_no) and fill in the
112 * subchannel information block (schib) with the connected subchannel's info.
113 * NOTE: The global variable blk_schid is updated to contain the subchannel
114 * information.
115 *
116 * If the caller gives dev_no=-1 then the user did not specify a boot device.
117 * In this case we'll just use the first potentially bootable device we find.
118 */
119 static bool find_subch(int dev_no)
120 {
121 int i, r;
122
123 for (i = 0; i < 0x10000; i++) {
124 r = is_dev_possibly_bootable(dev_no, i);
125 if (r < 0) {
126 break;
127 }
128 if (r == true) {
129 return true;
130 }
131 }
132
133 return false;
134 }
135
136 static void menu_setup(void)
137 {
138 if (memcmp(loadparm_str, LOADPARM_PROMPT, LOADPARM_LEN) == 0) {
139 menu_set_parms(QIPL_FLAG_BM_OPTS_CMD, 0);
140 return;
141 }
142
143 /* If loadparm was set to any other value, then do not enable menu */
144 if (memcmp(loadparm_str, LOADPARM_EMPTY, LOADPARM_LEN) != 0) {
145 return;
146 }
147
148 switch (iplb.pbt) {
149 case S390_IPL_TYPE_CCW:
150 case S390_IPL_TYPE_QEMU_SCSI:
151 menu_set_parms(qipl.qipl_flags & BOOT_MENU_FLAG_MASK,
152 qipl.boot_menu_timeout);
153 return;
154 }
155 }
156
157 /*
158 * Initialize the channel I/O subsystem so we can talk to our ipl/boot device.
159 */
160 static void css_setup(void)
161 {
162 /*
163 * Unconditionally enable mss support. In every sane configuration this
164 * will succeed; and even if it doesn't, stsch_err() can handle it.
165 */
166 enable_mss_facility();
167 }
168
169 /*
170 * Collect various pieces of information from the hypervisor/hardware that
171 * we'll use to determine exactly how we'll boot.
172 */
173 static void boot_setup(void)
174 {
175 char lpmsg[] = "LOADPARM=[________]\n";
176
177 sclp_get_loadparm_ascii(loadparm_str);
178 memcpy(lpmsg + 10, loadparm_str, 8);
179 sclp_print(lpmsg);
180
181 /*
182 * Clear out any potential S390EP magic (see jump_to_low_kernel()),
183 * so we don't taint our decision-making process during a reboot.
184 */
185 memset((char *)S390EP, 0, 6);
186
187 have_iplb = store_iplb(&iplb);
188 }
189
190 static void find_boot_device(void)
191 {
192 VDev *vdev = virtio_get_device();
193 bool found;
194
195 switch (iplb.pbt) {
196 case S390_IPL_TYPE_CCW:
197 debug_print_int("device no. ", iplb.ccw.devno);
198 blk_schid.ssid = iplb.ccw.ssid & 0x3;
199 debug_print_int("ssid ", blk_schid.ssid);
200 found = find_subch(iplb.ccw.devno);
201 break;
202 case S390_IPL_TYPE_QEMU_SCSI:
203 vdev->scsi_device_selected = true;
204 vdev->selected_scsi_device.channel = iplb.scsi.channel;
205 vdev->selected_scsi_device.target = iplb.scsi.target;
206 vdev->selected_scsi_device.lun = iplb.scsi.lun;
207 blk_schid.ssid = iplb.scsi.ssid & 0x3;
208 found = find_subch(iplb.scsi.devno);
209 break;
210 default:
211 panic("List-directed IPL not supported yet!\n");
212 }
213
214 IPL_assert(found, "Boot device not found\n");
215 }
216
217 static int virtio_setup(void)
218 {
219 VDev *vdev = virtio_get_device();
220 QemuIplParameters *early_qipl = (QemuIplParameters *)QIPL_ADDRESS;
221
222 memcpy(&qipl, early_qipl, sizeof(QemuIplParameters));
223
224 if (have_iplb) {
225 menu_setup();
226 }
227
228 if (virtio_get_device_type() == VIRTIO_ID_NET) {
229 sclp_print("Network boot device detected\n");
230 vdev->netboot_start_addr = qipl.netboot_start_addr;
231 } else {
232 int ret = virtio_blk_setup_device(blk_schid);
233 if (ret) {
234 return ret;
235 }
236 IPL_assert(virtio_ipl_disk_is_valid(), "No valid IPL device detected");
237 }
238
239 return 0;
240 }
241
242 static void ipl_boot_device(void)
243 {
244 switch (cutype) {
245 case CU_TYPE_DASD_3990:
246 case CU_TYPE_DASD_2107:
247 dasd_ipl(blk_schid, cutype); /* no return */
248 break;
249 case CU_TYPE_VIRTIO:
250 if (virtio_setup() == 0) {
251 zipl_load(); /* Only returns in case of errors */
252 }
253 break;
254 default:
255 print_int("Attempting to boot from unexpected device type", cutype);
256 panic("\nBoot failed.\n");
257 }
258 }
259
260 /*
261 * No boot device has been specified, so we have to scan through the
262 * channels to find one.
263 */
264 static void probe_boot_device(void)
265 {
266 int ssid, sch_no, ret;
267
268 for (ssid = 0; ssid < 0x3; ssid++) {
269 blk_schid.ssid = ssid;
270 for (sch_no = 0; sch_no < 0x10000; sch_no++) {
271 ret = is_dev_possibly_bootable(-1, sch_no);
272 if (ret < 0) {
273 break;
274 }
275 if (ret == true) {
276 ipl_boot_device(); /* Only returns if unsuccessful */
277 }
278 }
279 }
280
281 sclp_print("Could not find a suitable boot device (none specified)\n");
282 }
283
284 int main(void)
285 {
286 sclp_setup();
287 css_setup();
288 boot_setup();
289 if (have_iplb) {
290 find_boot_device();
291 ipl_boot_device();
292 } else {
293 probe_boot_device();
294 }
295
296 panic("Failed to load OS from hard disk\n");
297 return 0; /* make compiler happy */
298 }