xref: /linux/arch/s390/kernel/sthyi.c (revision 856e7c4b619af622d56b3b454f7bec32a170ac99)
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 
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  */
168 static u32 scale_cap(u32 in)
169 {
170 	return (0x10000 * in) / 100;
171 }
172 
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 
183 static void fill_stsi_mac(struct sthyi_sctns *sctns,
184 			  struct sysinfo_1_1_1 *sysinfo)
185 {
186 	if (stsi(sysinfo, 1, 1, 1))
187 		return;
188 
189 	sclp_ocf_cpc_name_copy(sctns->mac.infmname);
190 
191 	memcpy(sctns->mac.infmtype, sysinfo->type, sizeof(sctns->mac.infmtype));
192 	memcpy(sctns->mac.infmmanu, sysinfo->manufacturer, sizeof(sctns->mac.infmmanu));
193 	memcpy(sctns->mac.infmpman, sysinfo->plant, sizeof(sctns->mac.infmpman));
194 	memcpy(sctns->mac.infmseq, sysinfo->sequence, sizeof(sctns->mac.infmseq));
195 
196 	sctns->mac.infmval1 |= MAC_ID_VLD | MAC_NAME_VLD;
197 }
198 
199 static void fill_stsi_par(struct sthyi_sctns *sctns,
200 			  struct sysinfo_2_2_2 *sysinfo)
201 {
202 	if (stsi(sysinfo, 2, 2, 2))
203 		return;
204 
205 	sctns->par.infppnum = sysinfo->lpar_number;
206 	memcpy(sctns->par.infppnam, sysinfo->name, sizeof(sctns->par.infppnam));
207 
208 	sctns->par.infpval1 |= PAR_ID_VLD;
209 }
210 
211 static void fill_stsi(struct sthyi_sctns *sctns)
212 {
213 	void *sysinfo;
214 
215 	/* Errors are handled through the validity bits in the response. */
216 	sysinfo = (void *)__get_free_page(GFP_KERNEL);
217 	if (!sysinfo)
218 		return;
219 
220 	fill_stsi_mac(sctns, sysinfo);
221 	fill_stsi_par(sctns, sysinfo);
222 
223 	free_pages((unsigned long)sysinfo, 0);
224 }
225 
226 static void fill_diag_mac(struct sthyi_sctns *sctns,
227 			  struct diag204_x_phys_block *block,
228 			  void *diag224_buf)
229 {
230 	int i;
231 
232 	for (i = 0; i < block->hdr.cpus; i++) {
233 		switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
234 		case CP:
235 			if (block->cpus[i].weight == DED_WEIGHT)
236 				sctns->mac.infmdcps++;
237 			else
238 				sctns->mac.infmscps++;
239 			break;
240 		case IFL:
241 			if (block->cpus[i].weight == DED_WEIGHT)
242 				sctns->mac.infmdifl++;
243 			else
244 				sctns->mac.infmsifl++;
245 			break;
246 		}
247 	}
248 	sctns->mac.infmval1 |= MAC_CNT_VLD;
249 }
250 
251 /* Returns a pointer to the the next partition block. */
252 static struct diag204_x_part_block *lpar_cpu_inf(struct lpar_cpu_inf *part_inf,
253 						 bool this_lpar,
254 						 void *diag224_buf,
255 						 struct diag204_x_part_block *block)
256 {
257 	int i, capped = 0, weight_cp = 0, weight_ifl = 0;
258 	struct cpu_inf *cpu_inf;
259 
260 	for (i = 0; i < block->hdr.rcpus; i++) {
261 		if (!(block->cpus[i].cflag & DIAG204_CPU_ONLINE))
262 			continue;
263 
264 		switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
265 		case CP:
266 			cpu_inf = &part_inf->cp;
267 			if (block->cpus[i].cur_weight < DED_WEIGHT)
268 				weight_cp |= block->cpus[i].cur_weight;
269 			break;
270 		case IFL:
271 			cpu_inf = &part_inf->ifl;
272 			if (block->cpus[i].cur_weight < DED_WEIGHT)
273 				weight_ifl |= block->cpus[i].cur_weight;
274 			break;
275 		default:
276 			continue;
277 		}
278 
279 		if (!this_lpar)
280 			continue;
281 
282 		capped |= block->cpus[i].cflag & DIAG204_CPU_CAPPED;
283 		cpu_inf->lpar_cap |= block->cpus[i].cpu_type_cap;
284 		cpu_inf->lpar_grp_cap |= block->cpus[i].group_cpu_type_cap;
285 
286 		if (block->cpus[i].weight == DED_WEIGHT)
287 			cpu_inf->cpu_num_ded += 1;
288 		else
289 			cpu_inf->cpu_num_shd += 1;
290 	}
291 
292 	if (this_lpar && capped) {
293 		part_inf->cp.lpar_weight = weight_cp;
294 		part_inf->ifl.lpar_weight = weight_ifl;
295 	}
296 	part_inf->cp.all_weight += weight_cp;
297 	part_inf->ifl.all_weight += weight_ifl;
298 	return (struct diag204_x_part_block *)&block->cpus[i];
299 }
300 
301 static void fill_diag(struct sthyi_sctns *sctns)
302 {
303 	int i, r, pages;
304 	bool this_lpar;
305 	void *diag204_buf;
306 	void *diag224_buf = NULL;
307 	struct diag204_x_info_blk_hdr *ti_hdr;
308 	struct diag204_x_part_block *part_block;
309 	struct diag204_x_phys_block *phys_block;
310 	struct lpar_cpu_inf lpar_inf = {};
311 
312 	/* Errors are handled through the validity bits in the response. */
313 	pages = diag204((unsigned long)DIAG204_SUBC_RSI |
314 			(unsigned long)DIAG204_INFO_EXT, 0, NULL);
315 	if (pages <= 0)
316 		return;
317 
318 	diag204_buf = vmalloc(array_size(pages, PAGE_SIZE));
319 	if (!diag204_buf)
320 		return;
321 
322 	r = diag204((unsigned long)DIAG204_SUBC_STIB7 |
323 		    (unsigned long)DIAG204_INFO_EXT, pages, diag204_buf);
324 	if (r < 0)
325 		goto out;
326 
327 	diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
328 	if (!diag224_buf || diag224(diag224_buf))
329 		goto out;
330 
331 	ti_hdr = diag204_buf;
332 	part_block = diag204_buf + sizeof(*ti_hdr);
333 
334 	for (i = 0; i < ti_hdr->npar; i++) {
335 		/*
336 		 * For the calling lpar we also need to get the cpu
337 		 * caps and weights. The time information block header
338 		 * specifies the offset to the partition block of the
339 		 * caller lpar, so we know when we process its data.
340 		 */
341 		this_lpar = (void *)part_block - diag204_buf == ti_hdr->this_part;
342 		part_block = lpar_cpu_inf(&lpar_inf, this_lpar, diag224_buf,
343 					  part_block);
344 	}
345 
346 	phys_block = (struct diag204_x_phys_block *)part_block;
347 	part_block = diag204_buf + ti_hdr->this_part;
348 	if (part_block->hdr.mtid)
349 		sctns->par.infpflg1 = PAR_MT_EN;
350 
351 	sctns->par.infpval1 |= PAR_GRP_VLD;
352 	sctns->par.infplgcp = scale_cap(lpar_inf.cp.lpar_grp_cap);
353 	sctns->par.infplgif = scale_cap(lpar_inf.ifl.lpar_grp_cap);
354 	memcpy(sctns->par.infplgnm, part_block->hdr.hardware_group_name,
355 	       sizeof(sctns->par.infplgnm));
356 
357 	sctns->par.infpscps = lpar_inf.cp.cpu_num_shd;
358 	sctns->par.infpdcps = lpar_inf.cp.cpu_num_ded;
359 	sctns->par.infpsifl = lpar_inf.ifl.cpu_num_shd;
360 	sctns->par.infpdifl = lpar_inf.ifl.cpu_num_ded;
361 	sctns->par.infpval1 |= PAR_PCNT_VLD;
362 
363 	sctns->par.infpabcp = scale_cap(lpar_inf.cp.lpar_cap);
364 	sctns->par.infpabif = scale_cap(lpar_inf.ifl.lpar_cap);
365 	sctns->par.infpval1 |= PAR_ABS_VLD;
366 
367 	/*
368 	 * Everything below needs global performance data to be
369 	 * meaningful.
370 	 */
371 	if (!(ti_hdr->flags & DIAG204_LPAR_PHYS_FLG)) {
372 		sctns->hdr.infhflg1 |= HDR_PERF_UNAV;
373 		goto out;
374 	}
375 
376 	fill_diag_mac(sctns, phys_block, diag224_buf);
377 
378 	if (lpar_inf.cp.lpar_weight) {
379 		sctns->par.infpwbcp = sctns->mac.infmscps * 0x10000 *
380 			lpar_inf.cp.lpar_weight / lpar_inf.cp.all_weight;
381 	}
382 
383 	if (lpar_inf.ifl.lpar_weight) {
384 		sctns->par.infpwbif = sctns->mac.infmsifl * 0x10000 *
385 			lpar_inf.ifl.lpar_weight / lpar_inf.ifl.all_weight;
386 	}
387 	sctns->par.infpval1 |= PAR_WGHT_VLD;
388 
389 out:
390 	free_page((unsigned long)diag224_buf);
391 	vfree(diag204_buf);
392 }
393 
394 static int sthyi(u64 vaddr, u64 *rc)
395 {
396 	register u64 code asm("0") = 0;
397 	register u64 addr asm("2") = vaddr;
398 	register u64 rcode asm("3");
399 	int cc;
400 
401 	asm volatile(
402 		".insn   rre,0xB2560000,%[code],%[addr]\n"
403 		"ipm     %[cc]\n"
404 		"srl     %[cc],28\n"
405 		: [cc] "=d" (cc), "=d" (rcode)
406 		: [code] "d" (code), [addr] "a" (addr)
407 		: "memory", "cc");
408 	*rc = rcode;
409 	return cc;
410 }
411 
412 static int fill_dst(void *dst, u64 *rc)
413 {
414 	struct sthyi_sctns *sctns = (struct sthyi_sctns *)dst;
415 
416 	/*
417 	 * If the facility is on, we don't want to emulate the instruction.
418 	 * We ask the hypervisor to provide the data.
419 	 */
420 	if (test_facility(74))
421 		return sthyi((u64)dst, rc);
422 
423 	fill_hdr(sctns);
424 	fill_stsi(sctns);
425 	fill_diag(sctns);
426 	*rc = 0;
427 	return 0;
428 }
429 
430 static int sthyi_init_cache(void)
431 {
432 	if (sthyi_cache.info)
433 		return 0;
434 	sthyi_cache.info = (void *)get_zeroed_page(GFP_KERNEL);
435 	if (!sthyi_cache.info)
436 		return -ENOMEM;
437 	sthyi_cache.end = jiffies - 1; /* expired */
438 	return 0;
439 }
440 
441 static int sthyi_update_cache(u64 *rc)
442 {
443 	int r;
444 
445 	memset(sthyi_cache.info, 0, PAGE_SIZE);
446 	r = fill_dst(sthyi_cache.info, rc);
447 	if (r)
448 		return r;
449 	sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES;
450 	return r;
451 }
452 
453 /*
454  * sthyi_fill - Fill page with data returned by the STHYI instruction
455  *
456  * @dst: Pointer to zeroed page
457  * @rc:  Pointer for storing the return code of the instruction
458  *
459  * Fills the destination with system information returned by the STHYI
460  * instruction. The data is generated by emulation or execution of STHYI,
461  * if available. The return value is the condition code that would be
462  * returned, the rc parameter is the return code which is passed in
463  * register R2 + 1.
464  */
465 int sthyi_fill(void *dst, u64 *rc)
466 {
467 	int r;
468 
469 	mutex_lock(&sthyi_mutex);
470 	r = sthyi_init_cache();
471 	if (r)
472 		goto out;
473 
474 	if (time_is_before_jiffies(sthyi_cache.end)) {
475 		/* cache expired */
476 		r = sthyi_update_cache(rc);
477 		if (r)
478 			goto out;
479 	}
480 	*rc = 0;
481 	memcpy(dst, sthyi_cache.info, PAGE_SIZE);
482 out:
483 	mutex_unlock(&sthyi_mutex);
484 	return r;
485 }
486 EXPORT_SYMBOL_GPL(sthyi_fill);
487 
488 SYSCALL_DEFINE4(s390_sthyi, unsigned long, function_code, void __user *, buffer,
489 		u64 __user *, return_code, unsigned long, flags)
490 {
491 	u64 sthyi_rc;
492 	void *info;
493 	int r;
494 
495 	if (flags)
496 		return -EINVAL;
497 	if (function_code != STHYI_FC_CP_IFL_CAP)
498 		return -EOPNOTSUPP;
499 	info = (void *)get_zeroed_page(GFP_KERNEL);
500 	if (!info)
501 		return -ENOMEM;
502 	r = sthyi_fill(info, &sthyi_rc);
503 	if (r < 0)
504 		goto out;
505 	if (return_code && put_user(sthyi_rc, return_code)) {
506 		r = -EFAULT;
507 		goto out;
508 	}
509 	if (copy_to_user(buffer, info, PAGE_SIZE))
510 		r = -EFAULT;
511 out:
512 	free_page((unsigned long)info);
513 	return r;
514 }
515