1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * store hypervisor information instruction emulation functions.
4 *
5 * Copyright IBM Corp. 2016
6 * Author(s): Janosch Frank <frankja@linux.vnet.ibm.com>
7 */
8 #include <linux/errno.h>
9 #include <linux/pagemap.h>
10 #include <linux/vmalloc.h>
11 #include <linux/syscalls.h>
12 #include <linux/mutex.h>
13 #include <asm/asm-offsets.h>
14 #include <asm/sclp.h>
15 #include <asm/diag.h>
16 #include <asm/sysinfo.h>
17 #include <asm/ebcdic.h>
18 #include <asm/facility.h>
19 #include <asm/sthyi.h>
20 #include "entry.h"
21
22 #define DED_WEIGHT 0xffff
23 /*
24 * CP and IFL as EBCDIC strings, SP/0x40 determines the end of string
25 * as they are justified with spaces.
26 */
27 #define CP 0xc3d7404040404040UL
28 #define IFL 0xc9c6d34040404040UL
29
30 enum hdr_flags {
31 HDR_NOT_LPAR = 0x10,
32 HDR_STACK_INCM = 0x20,
33 HDR_STSI_UNAV = 0x40,
34 HDR_PERF_UNAV = 0x80,
35 };
36
37 enum mac_validity {
38 MAC_NAME_VLD = 0x20,
39 MAC_ID_VLD = 0x40,
40 MAC_CNT_VLD = 0x80,
41 };
42
43 enum par_flag {
44 PAR_MT_EN = 0x80,
45 };
46
47 enum par_validity {
48 PAR_GRP_VLD = 0x08,
49 PAR_ID_VLD = 0x10,
50 PAR_ABS_VLD = 0x20,
51 PAR_WGHT_VLD = 0x40,
52 PAR_PCNT_VLD = 0x80,
53 };
54
55 struct hdr_sctn {
56 u8 infhflg1;
57 u8 infhflg2; /* reserved */
58 u8 infhval1; /* reserved */
59 u8 infhval2; /* reserved */
60 u8 reserved[3];
61 u8 infhygct;
62 u16 infhtotl;
63 u16 infhdln;
64 u16 infmoff;
65 u16 infmlen;
66 u16 infpoff;
67 u16 infplen;
68 u16 infhoff1;
69 u16 infhlen1;
70 u16 infgoff1;
71 u16 infglen1;
72 u16 infhoff2;
73 u16 infhlen2;
74 u16 infgoff2;
75 u16 infglen2;
76 u16 infhoff3;
77 u16 infhlen3;
78 u16 infgoff3;
79 u16 infglen3;
80 u8 reserved2[4];
81 } __packed;
82
83 struct mac_sctn {
84 u8 infmflg1; /* reserved */
85 u8 infmflg2; /* reserved */
86 u8 infmval1;
87 u8 infmval2; /* reserved */
88 u16 infmscps;
89 u16 infmdcps;
90 u16 infmsifl;
91 u16 infmdifl;
92 char infmname[8];
93 char infmtype[4];
94 char infmmanu[16];
95 char infmseq[16];
96 char infmpman[4];
97 u8 reserved[4];
98 } __packed;
99
100 struct par_sctn {
101 u8 infpflg1;
102 u8 infpflg2; /* reserved */
103 u8 infpval1;
104 u8 infpval2; /* reserved */
105 u16 infppnum;
106 u16 infpscps;
107 u16 infpdcps;
108 u16 infpsifl;
109 u16 infpdifl;
110 u16 reserved;
111 char infppnam[8];
112 u32 infpwbcp;
113 u32 infpabcp;
114 u32 infpwbif;
115 u32 infpabif;
116 char infplgnm[8];
117 u32 infplgcp;
118 u32 infplgif;
119 } __packed;
120
121 struct sthyi_sctns {
122 struct hdr_sctn hdr;
123 struct mac_sctn mac;
124 struct par_sctn par;
125 } __packed;
126
127 struct cpu_inf {
128 u64 lpar_cap;
129 u64 lpar_grp_cap;
130 u64 lpar_weight;
131 u64 all_weight;
132 int cpu_num_ded;
133 int cpu_num_shd;
134 };
135
136 struct lpar_cpu_inf {
137 struct cpu_inf cp;
138 struct cpu_inf ifl;
139 };
140
141 /*
142 * STHYI requires extensive locking in the higher hypervisors
143 * and is very computational/memory expensive. Therefore we
144 * cache the retrieved data whose valid period is 1s.
145 */
146 #define CACHE_VALID_JIFFIES HZ
147
148 struct sthyi_info {
149 void *info;
150 unsigned long end;
151 };
152
153 static DEFINE_MUTEX(sthyi_mutex);
154 static struct sthyi_info sthyi_cache;
155
cpu_id(u8 ctidx,void * diag224_buf)156 static inline u64 cpu_id(u8 ctidx, void *diag224_buf)
157 {
158 return *((u64 *)(diag224_buf + (ctidx + 1) * DIAG204_CPU_NAME_LEN));
159 }
160
161 /*
162 * Scales the cpu capping from the lpar range to the one expected in
163 * sthyi data.
164 *
165 * diag204 reports a cap in hundredths of processor units.
166 * z/VM's range for one core is 0 - 0x10000.
167 */
scale_cap(u32 in)168 static u32 scale_cap(u32 in)
169 {
170 return (0x10000 * in) / 100;
171 }
172
fill_hdr(struct sthyi_sctns * sctns)173 static void fill_hdr(struct sthyi_sctns *sctns)
174 {
175 sctns->hdr.infhdln = sizeof(sctns->hdr);
176 sctns->hdr.infmoff = sizeof(sctns->hdr);
177 sctns->hdr.infmlen = sizeof(sctns->mac);
178 sctns->hdr.infplen = sizeof(sctns->par);
179 sctns->hdr.infpoff = sctns->hdr.infhdln + sctns->hdr.infmlen;
180 sctns->hdr.infhtotl = sctns->hdr.infpoff + sctns->hdr.infplen;
181 }
182
fill_stsi_mac(struct sthyi_sctns * sctns,struct sysinfo_1_1_1 * sysinfo)183 static void fill_stsi_mac(struct sthyi_sctns *sctns,
184 struct sysinfo_1_1_1 *sysinfo)
185 {
186 sclp_ocf_cpc_name_copy(sctns->mac.infmname);
187 if (*(u64 *)sctns->mac.infmname != 0)
188 sctns->mac.infmval1 |= MAC_NAME_VLD;
189
190 if (stsi(sysinfo, 1, 1, 1))
191 return;
192
193 memcpy(sctns->mac.infmtype, sysinfo->type, sizeof(sctns->mac.infmtype));
194 memcpy(sctns->mac.infmmanu, sysinfo->manufacturer, sizeof(sctns->mac.infmmanu));
195 memcpy(sctns->mac.infmpman, sysinfo->plant, sizeof(sctns->mac.infmpman));
196 memcpy(sctns->mac.infmseq, sysinfo->sequence, sizeof(sctns->mac.infmseq));
197
198 sctns->mac.infmval1 |= MAC_ID_VLD;
199 }
200
fill_stsi_par(struct sthyi_sctns * sctns,struct sysinfo_2_2_2 * sysinfo)201 static void fill_stsi_par(struct sthyi_sctns *sctns,
202 struct sysinfo_2_2_2 *sysinfo)
203 {
204 if (stsi(sysinfo, 2, 2, 2))
205 return;
206
207 sctns->par.infppnum = sysinfo->lpar_number;
208 memcpy(sctns->par.infppnam, sysinfo->name, sizeof(sctns->par.infppnam));
209
210 sctns->par.infpval1 |= PAR_ID_VLD;
211 }
212
fill_stsi(struct sthyi_sctns * sctns)213 static void fill_stsi(struct sthyi_sctns *sctns)
214 {
215 void *sysinfo;
216
217 /* Errors are handled through the validity bits in the response. */
218 sysinfo = (void *)__get_free_page(GFP_KERNEL);
219 if (!sysinfo)
220 return;
221
222 fill_stsi_mac(sctns, sysinfo);
223 fill_stsi_par(sctns, sysinfo);
224
225 free_pages((unsigned long)sysinfo, 0);
226 }
227
fill_diag_mac(struct sthyi_sctns * sctns,struct diag204_x_phys_block * block,void * diag224_buf)228 static void fill_diag_mac(struct sthyi_sctns *sctns,
229 struct diag204_x_phys_block *block,
230 void *diag224_buf)
231 {
232 int i;
233
234 for (i = 0; i < block->hdr.cpus; i++) {
235 switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
236 case CP:
237 if (block->cpus[i].weight == DED_WEIGHT)
238 sctns->mac.infmdcps++;
239 else
240 sctns->mac.infmscps++;
241 break;
242 case IFL:
243 if (block->cpus[i].weight == DED_WEIGHT)
244 sctns->mac.infmdifl++;
245 else
246 sctns->mac.infmsifl++;
247 break;
248 }
249 }
250 sctns->mac.infmval1 |= MAC_CNT_VLD;
251 }
252
253 /* Returns a pointer to the the next partition block. */
lpar_cpu_inf(struct lpar_cpu_inf * part_inf,bool this_lpar,void * diag224_buf,struct diag204_x_part_block * block)254 static struct diag204_x_part_block *lpar_cpu_inf(struct lpar_cpu_inf *part_inf,
255 bool this_lpar,
256 void *diag224_buf,
257 struct diag204_x_part_block *block)
258 {
259 int i, capped = 0, weight_cp = 0, weight_ifl = 0;
260 struct cpu_inf *cpu_inf;
261
262 for (i = 0; i < block->hdr.rcpus; i++) {
263 if (!(block->cpus[i].cflag & DIAG204_CPU_ONLINE))
264 continue;
265
266 switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
267 case CP:
268 cpu_inf = &part_inf->cp;
269 if (block->cpus[i].cur_weight < DED_WEIGHT)
270 weight_cp |= block->cpus[i].cur_weight;
271 break;
272 case IFL:
273 cpu_inf = &part_inf->ifl;
274 if (block->cpus[i].cur_weight < DED_WEIGHT)
275 weight_ifl |= block->cpus[i].cur_weight;
276 break;
277 default:
278 continue;
279 }
280
281 if (!this_lpar)
282 continue;
283
284 capped |= block->cpus[i].cflag & DIAG204_CPU_CAPPED;
285 cpu_inf->lpar_cap |= block->cpus[i].cpu_type_cap;
286 cpu_inf->lpar_grp_cap |= block->cpus[i].group_cpu_type_cap;
287
288 if (block->cpus[i].weight == DED_WEIGHT)
289 cpu_inf->cpu_num_ded += 1;
290 else
291 cpu_inf->cpu_num_shd += 1;
292 }
293
294 if (this_lpar && capped) {
295 part_inf->cp.lpar_weight = weight_cp;
296 part_inf->ifl.lpar_weight = weight_ifl;
297 }
298 part_inf->cp.all_weight += weight_cp;
299 part_inf->ifl.all_weight += weight_ifl;
300 return (struct diag204_x_part_block *)&block->cpus[i];
301 }
302
diag204_get_data(bool diag204_allow_busy)303 static void *diag204_get_data(bool diag204_allow_busy)
304 {
305 unsigned long subcode;
306 void *diag204_buf;
307 int pages, rc;
308
309 subcode = DIAG204_SUBC_RSI;
310 subcode |= DIAG204_INFO_EXT;
311 pages = diag204(subcode, 0, NULL);
312 if (pages < 0)
313 return ERR_PTR(pages);
314 if (pages == 0)
315 return ERR_PTR(-ENODATA);
316 diag204_buf = __vmalloc_node(array_size(pages, PAGE_SIZE),
317 PAGE_SIZE, GFP_KERNEL, NUMA_NO_NODE,
318 __builtin_return_address(0));
319 if (!diag204_buf)
320 return ERR_PTR(-ENOMEM);
321 subcode = DIAG204_SUBC_STIB7;
322 subcode |= DIAG204_INFO_EXT;
323 if (diag204_has_bif() && diag204_allow_busy)
324 subcode |= DIAG204_BIF_BIT;
325 rc = diag204(subcode, pages, diag204_buf);
326 if (rc < 0) {
327 vfree(diag204_buf);
328 return ERR_PTR(rc);
329 }
330 return diag204_buf;
331 }
332
is_diag204_cached(struct sthyi_sctns * sctns)333 static bool is_diag204_cached(struct sthyi_sctns *sctns)
334 {
335 /*
336 * Check if validity bits are set when diag204 data
337 * is gathered.
338 */
339 if (sctns->par.infpval1)
340 return true;
341 return false;
342 }
343
fill_diag(struct sthyi_sctns * sctns,void * diag204_buf)344 static void fill_diag(struct sthyi_sctns *sctns, void *diag204_buf)
345 {
346 int i;
347 bool this_lpar;
348 void *diag224_buf = NULL;
349 struct diag204_x_info_blk_hdr *ti_hdr;
350 struct diag204_x_part_block *part_block;
351 struct diag204_x_phys_block *phys_block;
352 struct lpar_cpu_inf lpar_inf = {};
353
354 diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
355 if (!diag224_buf || diag224(diag224_buf))
356 goto out;
357
358 ti_hdr = diag204_buf;
359 part_block = diag204_buf + sizeof(*ti_hdr);
360
361 for (i = 0; i < ti_hdr->npar; i++) {
362 /*
363 * For the calling lpar we also need to get the cpu
364 * caps and weights. The time information block header
365 * specifies the offset to the partition block of the
366 * caller lpar, so we know when we process its data.
367 */
368 this_lpar = (void *)part_block - diag204_buf == ti_hdr->this_part;
369 part_block = lpar_cpu_inf(&lpar_inf, this_lpar, diag224_buf,
370 part_block);
371 }
372
373 phys_block = (struct diag204_x_phys_block *)part_block;
374 part_block = diag204_buf + ti_hdr->this_part;
375 if (part_block->hdr.mtid)
376 sctns->par.infpflg1 = PAR_MT_EN;
377
378 sctns->par.infpval1 |= PAR_GRP_VLD;
379 sctns->par.infplgcp = scale_cap(lpar_inf.cp.lpar_grp_cap);
380 sctns->par.infplgif = scale_cap(lpar_inf.ifl.lpar_grp_cap);
381 memcpy(sctns->par.infplgnm, part_block->hdr.hardware_group_name,
382 sizeof(sctns->par.infplgnm));
383
384 sctns->par.infpscps = lpar_inf.cp.cpu_num_shd;
385 sctns->par.infpdcps = lpar_inf.cp.cpu_num_ded;
386 sctns->par.infpsifl = lpar_inf.ifl.cpu_num_shd;
387 sctns->par.infpdifl = lpar_inf.ifl.cpu_num_ded;
388 sctns->par.infpval1 |= PAR_PCNT_VLD;
389
390 sctns->par.infpabcp = scale_cap(lpar_inf.cp.lpar_cap);
391 sctns->par.infpabif = scale_cap(lpar_inf.ifl.lpar_cap);
392 sctns->par.infpval1 |= PAR_ABS_VLD;
393
394 /*
395 * Everything below needs global performance data to be
396 * meaningful.
397 */
398 if (!(ti_hdr->flags & DIAG204_LPAR_PHYS_FLG)) {
399 sctns->hdr.infhflg1 |= HDR_PERF_UNAV;
400 goto out;
401 }
402
403 fill_diag_mac(sctns, phys_block, diag224_buf);
404
405 if (lpar_inf.cp.lpar_weight) {
406 sctns->par.infpwbcp = sctns->mac.infmscps * 0x10000 *
407 lpar_inf.cp.lpar_weight / lpar_inf.cp.all_weight;
408 }
409
410 if (lpar_inf.ifl.lpar_weight) {
411 sctns->par.infpwbif = sctns->mac.infmsifl * 0x10000 *
412 lpar_inf.ifl.lpar_weight / lpar_inf.ifl.all_weight;
413 }
414 sctns->par.infpval1 |= PAR_WGHT_VLD;
415
416 out:
417 free_page((unsigned long)diag224_buf);
418 }
419
sthyi(u64 vaddr,u64 * rc)420 static int sthyi(u64 vaddr, u64 *rc)
421 {
422 union register_pair r1 = { .even = 0, }; /* subcode */
423 union register_pair r2 = { .even = vaddr, };
424 int cc;
425
426 asm volatile(
427 ".insn rre,0xB2560000,%[r1],%[r2]\n"
428 "ipm %[cc]\n"
429 "srl %[cc],28\n"
430 : [cc] "=&d" (cc), [r2] "+&d" (r2.pair)
431 : [r1] "d" (r1.pair)
432 : "memory", "cc");
433 *rc = r2.odd;
434 return cc;
435 }
436
fill_dst(void * dst,u64 * rc)437 static int fill_dst(void *dst, u64 *rc)
438 {
439 void *diag204_buf;
440
441 struct sthyi_sctns *sctns = (struct sthyi_sctns *)dst;
442
443 /*
444 * If the facility is on, we don't want to emulate the instruction.
445 * We ask the hypervisor to provide the data.
446 */
447 if (test_facility(74)) {
448 memset(dst, 0, PAGE_SIZE);
449 return sthyi((u64)dst, rc);
450 }
451 /*
452 * When emulating, if diag204 returns BUSY don't reset dst buffer
453 * and use cached data.
454 */
455 *rc = 0;
456 diag204_buf = diag204_get_data(is_diag204_cached(sctns));
457 if (IS_ERR(diag204_buf))
458 return PTR_ERR(diag204_buf);
459 memset(dst, 0, PAGE_SIZE);
460 fill_hdr(sctns);
461 fill_stsi(sctns);
462 fill_diag(sctns, diag204_buf);
463 vfree(diag204_buf);
464 return 0;
465 }
466
sthyi_init_cache(void)467 static int sthyi_init_cache(void)
468 {
469 if (sthyi_cache.info)
470 return 0;
471 sthyi_cache.info = (void *)get_zeroed_page(GFP_KERNEL);
472 if (!sthyi_cache.info)
473 return -ENOMEM;
474 sthyi_cache.end = jiffies - 1; /* expired */
475 return 0;
476 }
477
sthyi_update_cache(u64 * rc)478 static int sthyi_update_cache(u64 *rc)
479 {
480 int r;
481
482 r = fill_dst(sthyi_cache.info, rc);
483 if (r == 0) {
484 sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES;
485 } else if (r == -EBUSY) {
486 /* mark as expired and return 0 to keep using cached data */
487 sthyi_cache.end = jiffies - 1;
488 r = 0;
489 }
490 return r;
491 }
492
493 /*
494 * sthyi_fill - Fill page with data returned by the STHYI instruction
495 *
496 * @dst: Pointer to zeroed page
497 * @rc: Pointer for storing the return code of the instruction
498 *
499 * Fills the destination with system information returned by the STHYI
500 * instruction. The data is generated by emulation or execution of STHYI,
501 * if available. The return value is either a negative error value or
502 * the condition code that would be returned, the rc parameter is the
503 * return code which is passed in register R2 + 1.
504 */
sthyi_fill(void * dst,u64 * rc)505 int sthyi_fill(void *dst, u64 *rc)
506 {
507 int r;
508
509 mutex_lock(&sthyi_mutex);
510 r = sthyi_init_cache();
511 if (r)
512 goto out;
513
514 if (time_is_before_jiffies(sthyi_cache.end)) {
515 /* cache expired */
516 r = sthyi_update_cache(rc);
517 if (r)
518 goto out;
519 }
520 *rc = 0;
521 memcpy(dst, sthyi_cache.info, PAGE_SIZE);
522 out:
523 mutex_unlock(&sthyi_mutex);
524 return r;
525 }
526 EXPORT_SYMBOL_GPL(sthyi_fill);
527
SYSCALL_DEFINE4(s390_sthyi,unsigned long,function_code,void __user *,buffer,u64 __user *,return_code,unsigned long,flags)528 SYSCALL_DEFINE4(s390_sthyi, unsigned long, function_code, void __user *, buffer,
529 u64 __user *, return_code, unsigned long, flags)
530 {
531 u64 sthyi_rc;
532 void *info;
533 int r;
534
535 if (flags)
536 return -EINVAL;
537 if (function_code != STHYI_FC_CP_IFL_CAP)
538 return -EOPNOTSUPP;
539 info = (void *)get_zeroed_page(GFP_KERNEL);
540 if (!info)
541 return -ENOMEM;
542 r = sthyi_fill(info, &sthyi_rc);
543 if (r < 0)
544 goto out;
545 if (return_code && put_user(sthyi_rc, return_code)) {
546 r = -EFAULT;
547 goto out;
548 }
549 if (copy_to_user(buffer, info, PAGE_SIZE))
550 r = -EFAULT;
551 out:
552 free_page((unsigned long)info);
553 return r;
554 }
555