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11#include "s390-ccw.h"
12#include "virtio.h"
13
14static struct vring block;
15
16static char chsc_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
17
18static long kvm_hypercall(unsigned long nr, unsigned long param1,
19 unsigned long param2)
20{
21 register ulong r_nr asm("1") = nr;
22 register ulong r_param1 asm("2") = param1;
23 register ulong r_param2 asm("3") = param2;
24 register long retval asm("2");
25
26 asm volatile ("diag 2,4,0x500"
27 : "=d" (retval)
28 : "d" (r_nr), "0" (r_param1), "r"(r_param2)
29 : "memory", "cc");
30
31 return retval;
32}
33
34static void virtio_notify(struct subchannel_id schid)
35{
36 kvm_hypercall(KVM_S390_VIRTIO_CCW_NOTIFY, *(u32 *)&schid, 0);
37}
38
39
40
41
42
43static int drain_irqs(struct subchannel_id schid)
44{
45 struct irb irb = {};
46 int r = 0;
47
48 while (1) {
49
50 if (tsch(schid, &irb)) {
51
52 if (irb.scsw.cstat) {
53 r = -EIO;
54 } else if (irb.scsw.dstat != 0xc) {
55 r = -EIO;
56 }
57 return r;
58 }
59 }
60}
61
62static int run_ccw(struct subchannel_id schid, int cmd, void *ptr, int len)
63{
64 struct ccw1 ccw = {};
65 struct cmd_orb orb = {};
66 struct schib schib;
67 int r;
68
69
70 stsch_err(schid, &schib);
71 schib.scsw.ctrl = SCSW_FCTL_START_FUNC;
72 msch(schid, &schib);
73
74
75 orb.fmt = 1;
76 orb.cpa = (u32)(long)&ccw;
77 orb.lpm = 0x80;
78
79 ccw.cmd_code = cmd;
80 ccw.cda = (long)ptr;
81 ccw.count = len;
82
83 r = ssch(schid, &orb);
84
85
86
87
88
89 if (!r) {
90 r = drain_irqs(schid);
91 }
92 return r;
93}
94
95static void virtio_set_status(struct subchannel_id schid,
96 unsigned long dev_addr)
97{
98 unsigned char status = dev_addr;
99 if (run_ccw(schid, CCW_CMD_WRITE_STATUS, &status, sizeof(status))) {
100 virtio_panic("Could not write status to host!\n");
101 }
102}
103
104static void virtio_reset(struct subchannel_id schid)
105{
106 run_ccw(schid, CCW_CMD_VDEV_RESET, NULL, 0);
107}
108
109static void vring_init(struct vring *vr, unsigned int num, void *p,
110 unsigned long align)
111{
112 debug_print_addr("init p", p);
113 vr->num = num;
114 vr->desc = p;
115 vr->avail = p + num*sizeof(struct vring_desc);
116 vr->used = (void *)(((unsigned long)&vr->avail->ring[num] + align-1)
117 & ~(align - 1));
118
119
120 vr->avail->flags = 0;
121 vr->avail->idx = 0;
122
123
124 vr->used->flags = VRING_USED_F_NO_NOTIFY;
125 vr->used->idx = 0;
126 vr->used_idx = 0;
127 vr->next_idx = 0;
128
129 debug_print_addr("init vr", vr);
130}
131
132static void vring_notify(struct subchannel_id schid)
133{
134 virtio_notify(schid);
135}
136
137static void vring_send_buf(struct vring *vr, void *p, int len, int flags)
138{
139
140 if (!(flags & VRING_HIDDEN_IS_CHAIN)) {
141 vr->avail->ring[vr->avail->idx % vr->num] = vr->next_idx;
142 }
143
144 vr->desc[vr->next_idx].addr = (ulong)p;
145 vr->desc[vr->next_idx].len = len;
146 vr->desc[vr->next_idx].flags = flags & ~VRING_HIDDEN_IS_CHAIN;
147 vr->desc[vr->next_idx].next = vr->next_idx;
148 vr->desc[vr->next_idx].next++;
149 vr->next_idx++;
150
151
152 if (!(flags & VRING_DESC_F_NEXT)) {
153 vr->avail->idx++;
154 }
155}
156
157static u64 get_clock(void)
158{
159 u64 r;
160
161 asm volatile("stck %0" : "=Q" (r) : : "cc");
162 return r;
163}
164
165static ulong get_second(void)
166{
167 return (get_clock() >> 12) / 1000000;
168}
169
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174
175
176
177static int vring_wait_reply(struct vring *vr, int timeout)
178{
179 ulong target_second = get_second() + timeout;
180 struct subchannel_id schid = vr->schid;
181 int r = 0;
182
183
184 while (vr->used->idx == vr->used_idx) {
185 vring_notify(schid);
186 if (timeout && (get_second() >= target_second)) {
187 r = 1;
188 break;
189 }
190 yield();
191 }
192
193 vr->used_idx = vr->used->idx;
194 vr->next_idx = 0;
195 vr->desc[0].len = 0;
196 vr->desc[0].flags = 0;
197
198 return r;
199}
200
201
202
203
204
205int virtio_read_many(ulong sector, void *load_addr, int sec_num)
206{
207 struct virtio_blk_outhdr out_hdr;
208 u8 status;
209 int r;
210
211
212 out_hdr.type = VIRTIO_BLK_T_IN;
213 out_hdr.ioprio = 99;
214 out_hdr.sector = virtio_sector_adjust(sector);
215
216 vring_send_buf(&block, &out_hdr, sizeof(out_hdr), VRING_DESC_F_NEXT);
217
218
219 vring_send_buf(&block, load_addr, virtio_get_block_size() * sec_num,
220 VRING_DESC_F_WRITE | VRING_HIDDEN_IS_CHAIN |
221 VRING_DESC_F_NEXT);
222
223
224 vring_send_buf(&block, &status, sizeof(u8), VRING_DESC_F_WRITE |
225 VRING_HIDDEN_IS_CHAIN);
226
227
228 vring_wait_reply(&block, 0);
229
230 r = drain_irqs(block.schid);
231 if (r) {
232
233 status = 1;
234 }
235 return status;
236}
237
238unsigned long virtio_load_direct(ulong rec_list1, ulong rec_list2,
239 ulong subchan_id, void *load_addr)
240{
241 u8 status;
242 int sec = rec_list1;
243 int sec_num = ((rec_list2 >> 32) & 0xffff) + 1;
244 int sec_len = rec_list2 >> 48;
245 ulong addr = (ulong)load_addr;
246
247 if (sec_len != virtio_get_block_size()) {
248 return -1;
249 }
250
251 sclp_print(".");
252 status = virtio_read_many(sec, (void *)addr, sec_num);
253 if (status) {
254 virtio_panic("I/O Error");
255 }
256 addr += sec_num * virtio_get_block_size();
257
258 return addr;
259}
260
261int virtio_read(ulong sector, void *load_addr)
262{
263 return virtio_read_many(sector, load_addr, 1);
264}
265
266static VirtioBlkConfig blk_cfg = {};
267static bool guessed_disk_nature;
268
269bool virtio_guessed_disk_nature(void)
270{
271 return guessed_disk_nature;
272}
273
274void virtio_assume_scsi(void)
275{
276 guessed_disk_nature = true;
277 blk_cfg.blk_size = 512;
278 blk_cfg.physical_block_exp = 0;
279}
280
281void virtio_assume_eckd(void)
282{
283 guessed_disk_nature = true;
284 blk_cfg.blk_size = 4096;
285 blk_cfg.physical_block_exp = 0;
286
287
288 blk_cfg.geometry.heads = 15;
289 blk_cfg.geometry.sectors = 12;
290}
291
292bool virtio_disk_is_scsi(void)
293{
294 if (guessed_disk_nature) {
295 return (virtio_get_block_size() == 512);
296 }
297 return (blk_cfg.geometry.heads == 255)
298 && (blk_cfg.geometry.sectors == 63)
299 && (virtio_get_block_size() == 512);
300}
301
302
303
304
305
306static inline u8 virtio_eckd_sectors_for_block_size(int size)
307{
308 switch (size) {
309 case 512:
310 return 49;
311 case 1024:
312 return 33;
313 case 2048:
314 return 21;
315 case 4096:
316 return 12;
317 }
318 return 0;
319}
320
321bool virtio_disk_is_eckd(void)
322{
323 const int block_size = virtio_get_block_size();
324
325 if (guessed_disk_nature) {
326 return (block_size == 4096);
327 }
328 return (blk_cfg.geometry.heads == 15)
329 && (blk_cfg.geometry.sectors ==
330 virtio_eckd_sectors_for_block_size(block_size));
331}
332
333bool virtio_ipl_disk_is_valid(void)
334{
335 return virtio_disk_is_scsi() || virtio_disk_is_eckd();
336}
337
338int virtio_get_block_size(void)
339{
340 return blk_cfg.blk_size << blk_cfg.physical_block_exp;
341}
342
343uint8_t virtio_get_heads(void)
344{
345 return blk_cfg.geometry.heads;
346}
347
348uint8_t virtio_get_sectors(void)
349{
350 return blk_cfg.geometry.sectors;
351}
352
353uint64_t virtio_get_blocks(void)
354{
355 return blk_cfg.capacity /
356 (virtio_get_block_size() / VIRTIO_SECTOR_SIZE);
357}
358
359void virtio_setup_block(struct subchannel_id schid)
360{
361 struct vq_info_block info;
362 struct vq_config_block config = {};
363
364 blk_cfg.blk_size = 0;
365 guessed_disk_nature = false;
366
367 virtio_reset(schid);
368
369
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371
372
373
374
375 config.index = 0;
376 if (run_ccw(schid, CCW_CMD_READ_VQ_CONF, &config, sizeof(config))) {
377 virtio_panic("Could not get block device VQ configuration\n");
378 }
379 if (run_ccw(schid, CCW_CMD_READ_CONF, &blk_cfg, sizeof(blk_cfg))) {
380 virtio_panic("Could not get block device configuration\n");
381 }
382 vring_init(&block, config.num, ring_area,
383 KVM_S390_VIRTIO_RING_ALIGN);
384
385 info.queue = (unsigned long long) ring_area;
386 info.align = KVM_S390_VIRTIO_RING_ALIGN;
387 info.index = 0;
388 info.num = config.num;
389 block.schid = schid;
390
391 if (!run_ccw(schid, CCW_CMD_SET_VQ, &info, sizeof(info))) {
392 virtio_set_status(schid, VIRTIO_CONFIG_S_DRIVER_OK);
393 }
394
395 if (!virtio_ipl_disk_is_valid()) {
396
397 memset(&blk_cfg, 0, sizeof(blk_cfg));
398 virtio_assume_scsi();
399 }
400}
401
402bool virtio_is_blk(struct subchannel_id schid)
403{
404 int r;
405 struct senseid senseid = {};
406
407
408 r = run_ccw(schid, CCW_CMD_SENSE_ID, &senseid, sizeof(senseid));
409 if (r) {
410 return false;
411 }
412 if ((senseid.cu_type != 0x3832) || (senseid.cu_model != VIRTIO_ID_BLOCK)) {
413 return false;
414 }
415
416 return true;
417}
418
419int enable_mss_facility(void)
420{
421 int ret;
422 struct chsc_area_sda *sda_area = (struct chsc_area_sda *) chsc_page;
423
424 memset(sda_area, 0, PAGE_SIZE);
425 sda_area->request.length = 0x0400;
426 sda_area->request.code = 0x0031;
427 sda_area->operation_code = 0x2;
428
429 ret = chsc(sda_area);
430 if ((ret == 0) && (sda_area->response.code == 0x0001)) {
431 return 0;
432 }
433 return -EIO;
434}
435