xref: /openbmc/linux/arch/s390/kernel/sthyi.c (revision 680ef72a)
1 /*
2  * store hypervisor information instruction emulation functions.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License (version 2 only)
6  * as published by the Free Software Foundation.
7  *
8  * Copyright IBM Corp. 2016
9  * Author(s): Janosch Frank <frankja@linux.vnet.ibm.com>
10  */
11 #include <linux/errno.h>
12 #include <linux/pagemap.h>
13 #include <linux/vmalloc.h>
14 #include <linux/syscalls.h>
15 #include <linux/mutex.h>
16 #include <asm/asm-offsets.h>
17 #include <asm/sclp.h>
18 #include <asm/diag.h>
19 #include <asm/sysinfo.h>
20 #include <asm/ebcdic.h>
21 #include <asm/facility.h>
22 #include <asm/sthyi.h>
23 #include "entry.h"
24 
25 #define DED_WEIGHT 0xffff
26 /*
27  * CP and IFL as EBCDIC strings, SP/0x40 determines the end of string
28  * as they are justified with spaces.
29  */
30 #define CP  0xc3d7404040404040UL
31 #define IFL 0xc9c6d34040404040UL
32 
33 enum hdr_flags {
34 	HDR_NOT_LPAR   = 0x10,
35 	HDR_STACK_INCM = 0x20,
36 	HDR_STSI_UNAV  = 0x40,
37 	HDR_PERF_UNAV  = 0x80,
38 };
39 
40 enum mac_validity {
41 	MAC_NAME_VLD = 0x20,
42 	MAC_ID_VLD   = 0x40,
43 	MAC_CNT_VLD  = 0x80,
44 };
45 
46 enum par_flag {
47 	PAR_MT_EN = 0x80,
48 };
49 
50 enum par_validity {
51 	PAR_GRP_VLD  = 0x08,
52 	PAR_ID_VLD   = 0x10,
53 	PAR_ABS_VLD  = 0x20,
54 	PAR_WGHT_VLD = 0x40,
55 	PAR_PCNT_VLD  = 0x80,
56 };
57 
58 struct hdr_sctn {
59 	u8 infhflg1;
60 	u8 infhflg2; /* reserved */
61 	u8 infhval1; /* reserved */
62 	u8 infhval2; /* reserved */
63 	u8 reserved[3];
64 	u8 infhygct;
65 	u16 infhtotl;
66 	u16 infhdln;
67 	u16 infmoff;
68 	u16 infmlen;
69 	u16 infpoff;
70 	u16 infplen;
71 	u16 infhoff1;
72 	u16 infhlen1;
73 	u16 infgoff1;
74 	u16 infglen1;
75 	u16 infhoff2;
76 	u16 infhlen2;
77 	u16 infgoff2;
78 	u16 infglen2;
79 	u16 infhoff3;
80 	u16 infhlen3;
81 	u16 infgoff3;
82 	u16 infglen3;
83 	u8 reserved2[4];
84 } __packed;
85 
86 struct mac_sctn {
87 	u8 infmflg1; /* reserved */
88 	u8 infmflg2; /* reserved */
89 	u8 infmval1;
90 	u8 infmval2; /* reserved */
91 	u16 infmscps;
92 	u16 infmdcps;
93 	u16 infmsifl;
94 	u16 infmdifl;
95 	char infmname[8];
96 	char infmtype[4];
97 	char infmmanu[16];
98 	char infmseq[16];
99 	char infmpman[4];
100 	u8 reserved[4];
101 } __packed;
102 
103 struct par_sctn {
104 	u8 infpflg1;
105 	u8 infpflg2; /* reserved */
106 	u8 infpval1;
107 	u8 infpval2; /* reserved */
108 	u16 infppnum;
109 	u16 infpscps;
110 	u16 infpdcps;
111 	u16 infpsifl;
112 	u16 infpdifl;
113 	u16 reserved;
114 	char infppnam[8];
115 	u32 infpwbcp;
116 	u32 infpabcp;
117 	u32 infpwbif;
118 	u32 infpabif;
119 	char infplgnm[8];
120 	u32 infplgcp;
121 	u32 infplgif;
122 } __packed;
123 
124 struct sthyi_sctns {
125 	struct hdr_sctn hdr;
126 	struct mac_sctn mac;
127 	struct par_sctn par;
128 } __packed;
129 
130 struct cpu_inf {
131 	u64 lpar_cap;
132 	u64 lpar_grp_cap;
133 	u64 lpar_weight;
134 	u64 all_weight;
135 	int cpu_num_ded;
136 	int cpu_num_shd;
137 };
138 
139 struct lpar_cpu_inf {
140 	struct cpu_inf cp;
141 	struct cpu_inf ifl;
142 };
143 
144 /*
145  * STHYI requires extensive locking in the higher hypervisors
146  * and is very computational/memory expensive. Therefore we
147  * cache the retrieved data whose valid period is 1s.
148  */
149 #define CACHE_VALID_JIFFIES	HZ
150 
151 struct sthyi_info {
152 	void *info;
153 	unsigned long end;
154 };
155 
156 static DEFINE_MUTEX(sthyi_mutex);
157 static struct sthyi_info sthyi_cache;
158 
159 static inline u64 cpu_id(u8 ctidx, void *diag224_buf)
160 {
161 	return *((u64 *)(diag224_buf + (ctidx + 1) * DIAG204_CPU_NAME_LEN));
162 }
163 
164 /*
165  * Scales the cpu capping from the lpar range to the one expected in
166  * sthyi data.
167  *
168  * diag204 reports a cap in hundredths of processor units.
169  * z/VM's range for one core is 0 - 0x10000.
170  */
171 static u32 scale_cap(u32 in)
172 {
173 	return (0x10000 * in) / 100;
174 }
175 
176 static void fill_hdr(struct sthyi_sctns *sctns)
177 {
178 	sctns->hdr.infhdln = sizeof(sctns->hdr);
179 	sctns->hdr.infmoff = sizeof(sctns->hdr);
180 	sctns->hdr.infmlen = sizeof(sctns->mac);
181 	sctns->hdr.infplen = sizeof(sctns->par);
182 	sctns->hdr.infpoff = sctns->hdr.infhdln + sctns->hdr.infmlen;
183 	sctns->hdr.infhtotl = sctns->hdr.infpoff + sctns->hdr.infplen;
184 }
185 
186 static void fill_stsi_mac(struct sthyi_sctns *sctns,
187 			  struct sysinfo_1_1_1 *sysinfo)
188 {
189 	if (stsi(sysinfo, 1, 1, 1))
190 		return;
191 
192 	sclp_ocf_cpc_name_copy(sctns->mac.infmname);
193 
194 	memcpy(sctns->mac.infmtype, sysinfo->type, sizeof(sctns->mac.infmtype));
195 	memcpy(sctns->mac.infmmanu, sysinfo->manufacturer, sizeof(sctns->mac.infmmanu));
196 	memcpy(sctns->mac.infmpman, sysinfo->plant, sizeof(sctns->mac.infmpman));
197 	memcpy(sctns->mac.infmseq, sysinfo->sequence, sizeof(sctns->mac.infmseq));
198 
199 	sctns->mac.infmval1 |= MAC_ID_VLD | MAC_NAME_VLD;
200 }
201 
202 static void fill_stsi_par(struct sthyi_sctns *sctns,
203 			  struct sysinfo_2_2_2 *sysinfo)
204 {
205 	if (stsi(sysinfo, 2, 2, 2))
206 		return;
207 
208 	sctns->par.infppnum = sysinfo->lpar_number;
209 	memcpy(sctns->par.infppnam, sysinfo->name, sizeof(sctns->par.infppnam));
210 
211 	sctns->par.infpval1 |= PAR_ID_VLD;
212 }
213 
214 static void fill_stsi(struct sthyi_sctns *sctns)
215 {
216 	void *sysinfo;
217 
218 	/* Errors are handled through the validity bits in the response. */
219 	sysinfo = (void *)__get_free_page(GFP_KERNEL);
220 	if (!sysinfo)
221 		return;
222 
223 	fill_stsi_mac(sctns, sysinfo);
224 	fill_stsi_par(sctns, sysinfo);
225 
226 	free_pages((unsigned long)sysinfo, 0);
227 }
228 
229 static void fill_diag_mac(struct sthyi_sctns *sctns,
230 			  struct diag204_x_phys_block *block,
231 			  void *diag224_buf)
232 {
233 	int i;
234 
235 	for (i = 0; i < block->hdr.cpus; i++) {
236 		switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
237 		case CP:
238 			if (block->cpus[i].weight == DED_WEIGHT)
239 				sctns->mac.infmdcps++;
240 			else
241 				sctns->mac.infmscps++;
242 			break;
243 		case IFL:
244 			if (block->cpus[i].weight == DED_WEIGHT)
245 				sctns->mac.infmdifl++;
246 			else
247 				sctns->mac.infmsifl++;
248 			break;
249 		}
250 	}
251 	sctns->mac.infmval1 |= MAC_CNT_VLD;
252 }
253 
254 /* Returns a pointer to the the next partition block. */
255 static struct diag204_x_part_block *lpar_cpu_inf(struct lpar_cpu_inf *part_inf,
256 						 bool this_lpar,
257 						 void *diag224_buf,
258 						 struct diag204_x_part_block *block)
259 {
260 	int i, capped = 0, weight_cp = 0, weight_ifl = 0;
261 	struct cpu_inf *cpu_inf;
262 
263 	for (i = 0; i < block->hdr.rcpus; i++) {
264 		if (!(block->cpus[i].cflag & DIAG204_CPU_ONLINE))
265 			continue;
266 
267 		switch (cpu_id(block->cpus[i].ctidx, diag224_buf)) {
268 		case CP:
269 			cpu_inf = &part_inf->cp;
270 			if (block->cpus[i].cur_weight < DED_WEIGHT)
271 				weight_cp |= block->cpus[i].cur_weight;
272 			break;
273 		case IFL:
274 			cpu_inf = &part_inf->ifl;
275 			if (block->cpus[i].cur_weight < DED_WEIGHT)
276 				weight_ifl |= block->cpus[i].cur_weight;
277 			break;
278 		default:
279 			continue;
280 		}
281 
282 		if (!this_lpar)
283 			continue;
284 
285 		capped |= block->cpus[i].cflag & DIAG204_CPU_CAPPED;
286 		cpu_inf->lpar_cap |= block->cpus[i].cpu_type_cap;
287 		cpu_inf->lpar_grp_cap |= block->cpus[i].group_cpu_type_cap;
288 
289 		if (block->cpus[i].weight == DED_WEIGHT)
290 			cpu_inf->cpu_num_ded += 1;
291 		else
292 			cpu_inf->cpu_num_shd += 1;
293 	}
294 
295 	if (this_lpar && capped) {
296 		part_inf->cp.lpar_weight = weight_cp;
297 		part_inf->ifl.lpar_weight = weight_ifl;
298 	}
299 	part_inf->cp.all_weight += weight_cp;
300 	part_inf->ifl.all_weight += weight_ifl;
301 	return (struct diag204_x_part_block *)&block->cpus[i];
302 }
303 
304 static void fill_diag(struct sthyi_sctns *sctns)
305 {
306 	int i, r, pages;
307 	bool this_lpar;
308 	void *diag204_buf;
309 	void *diag224_buf = NULL;
310 	struct diag204_x_info_blk_hdr *ti_hdr;
311 	struct diag204_x_part_block *part_block;
312 	struct diag204_x_phys_block *phys_block;
313 	struct lpar_cpu_inf lpar_inf = {};
314 
315 	/* Errors are handled through the validity bits in the response. */
316 	pages = diag204((unsigned long)DIAG204_SUBC_RSI |
317 			(unsigned long)DIAG204_INFO_EXT, 0, NULL);
318 	if (pages <= 0)
319 		return;
320 
321 	diag204_buf = vmalloc(PAGE_SIZE * pages);
322 	if (!diag204_buf)
323 		return;
324 
325 	r = diag204((unsigned long)DIAG204_SUBC_STIB7 |
326 		    (unsigned long)DIAG204_INFO_EXT, pages, diag204_buf);
327 	if (r < 0)
328 		goto out;
329 
330 	diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
331 	if (!diag224_buf || diag224(diag224_buf))
332 		goto out;
333 
334 	ti_hdr = diag204_buf;
335 	part_block = diag204_buf + sizeof(*ti_hdr);
336 
337 	for (i = 0; i < ti_hdr->npar; i++) {
338 		/*
339 		 * For the calling lpar we also need to get the cpu
340 		 * caps and weights. The time information block header
341 		 * specifies the offset to the partition block of the
342 		 * caller lpar, so we know when we process its data.
343 		 */
344 		this_lpar = (void *)part_block - diag204_buf == ti_hdr->this_part;
345 		part_block = lpar_cpu_inf(&lpar_inf, this_lpar, diag224_buf,
346 					  part_block);
347 	}
348 
349 	phys_block = (struct diag204_x_phys_block *)part_block;
350 	part_block = diag204_buf + ti_hdr->this_part;
351 	if (part_block->hdr.mtid)
352 		sctns->par.infpflg1 = PAR_MT_EN;
353 
354 	sctns->par.infpval1 |= PAR_GRP_VLD;
355 	sctns->par.infplgcp = scale_cap(lpar_inf.cp.lpar_grp_cap);
356 	sctns->par.infplgif = scale_cap(lpar_inf.ifl.lpar_grp_cap);
357 	memcpy(sctns->par.infplgnm, part_block->hdr.hardware_group_name,
358 	       sizeof(sctns->par.infplgnm));
359 
360 	sctns->par.infpscps = lpar_inf.cp.cpu_num_shd;
361 	sctns->par.infpdcps = lpar_inf.cp.cpu_num_ded;
362 	sctns->par.infpsifl = lpar_inf.ifl.cpu_num_shd;
363 	sctns->par.infpdifl = lpar_inf.ifl.cpu_num_ded;
364 	sctns->par.infpval1 |= PAR_PCNT_VLD;
365 
366 	sctns->par.infpabcp = scale_cap(lpar_inf.cp.lpar_cap);
367 	sctns->par.infpabif = scale_cap(lpar_inf.ifl.lpar_cap);
368 	sctns->par.infpval1 |= PAR_ABS_VLD;
369 
370 	/*
371 	 * Everything below needs global performance data to be
372 	 * meaningful.
373 	 */
374 	if (!(ti_hdr->flags & DIAG204_LPAR_PHYS_FLG)) {
375 		sctns->hdr.infhflg1 |= HDR_PERF_UNAV;
376 		goto out;
377 	}
378 
379 	fill_diag_mac(sctns, phys_block, diag224_buf);
380 
381 	if (lpar_inf.cp.lpar_weight) {
382 		sctns->par.infpwbcp = sctns->mac.infmscps * 0x10000 *
383 			lpar_inf.cp.lpar_weight / lpar_inf.cp.all_weight;
384 	}
385 
386 	if (lpar_inf.ifl.lpar_weight) {
387 		sctns->par.infpwbif = sctns->mac.infmsifl * 0x10000 *
388 			lpar_inf.ifl.lpar_weight / lpar_inf.ifl.all_weight;
389 	}
390 	sctns->par.infpval1 |= PAR_WGHT_VLD;
391 
392 out:
393 	free_page((unsigned long)diag224_buf);
394 	vfree(diag204_buf);
395 }
396 
397 static int sthyi(u64 vaddr, u64 *rc)
398 {
399 	register u64 code asm("0") = 0;
400 	register u64 addr asm("2") = vaddr;
401 	register u64 rcode asm("3");
402 	int cc;
403 
404 	asm volatile(
405 		".insn   rre,0xB2560000,%[code],%[addr]\n"
406 		"ipm     %[cc]\n"
407 		"srl     %[cc],28\n"
408 		: [cc] "=d" (cc), "=d" (rcode)
409 		: [code] "d" (code), [addr] "a" (addr)
410 		: "memory", "cc");
411 	*rc = rcode;
412 	return cc;
413 }
414 
415 static int fill_dst(void *dst, u64 *rc)
416 {
417 	struct sthyi_sctns *sctns = (struct sthyi_sctns *)dst;
418 
419 	/*
420 	 * If the facility is on, we don't want to emulate the instruction.
421 	 * We ask the hypervisor to provide the data.
422 	 */
423 	if (test_facility(74))
424 		return sthyi((u64)dst, rc);
425 
426 	fill_hdr(sctns);
427 	fill_stsi(sctns);
428 	fill_diag(sctns);
429 	*rc = 0;
430 	return 0;
431 }
432 
433 static int sthyi_init_cache(void)
434 {
435 	if (sthyi_cache.info)
436 		return 0;
437 	sthyi_cache.info = (void *)get_zeroed_page(GFP_KERNEL);
438 	if (!sthyi_cache.info)
439 		return -ENOMEM;
440 	sthyi_cache.end = jiffies - 1; /* expired */
441 	return 0;
442 }
443 
444 static int sthyi_update_cache(u64 *rc)
445 {
446 	int r;
447 
448 	memset(sthyi_cache.info, 0, PAGE_SIZE);
449 	r = fill_dst(sthyi_cache.info, rc);
450 	if (r)
451 		return r;
452 	sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES;
453 	return r;
454 }
455 
456 /*
457  * sthyi_fill - Fill page with data returned by the STHYI instruction
458  *
459  * @dst: Pointer to zeroed page
460  * @rc:  Pointer for storing the return code of the instruction
461  *
462  * Fills the destination with system information returned by the STHYI
463  * instruction. The data is generated by emulation or execution of STHYI,
464  * if available. The return value is the condition code that would be
465  * returned, the rc parameter is the return code which is passed in
466  * register R2 + 1.
467  */
468 int sthyi_fill(void *dst, u64 *rc)
469 {
470 	int r;
471 
472 	mutex_lock(&sthyi_mutex);
473 	r = sthyi_init_cache();
474 	if (r)
475 		goto out;
476 
477 	if (time_is_before_jiffies(sthyi_cache.end)) {
478 		/* cache expired */
479 		r = sthyi_update_cache(rc);
480 		if (r)
481 			goto out;
482 	}
483 	*rc = 0;
484 	memcpy(dst, sthyi_cache.info, PAGE_SIZE);
485 out:
486 	mutex_unlock(&sthyi_mutex);
487 	return r;
488 }
489 EXPORT_SYMBOL_GPL(sthyi_fill);
490 
491 SYSCALL_DEFINE4(s390_sthyi, unsigned long, function_code, void __user *, buffer,
492 		u64 __user *, return_code, unsigned long, flags)
493 {
494 	u64 sthyi_rc;
495 	void *info;
496 	int r;
497 
498 	if (flags)
499 		return -EINVAL;
500 	if (function_code != STHYI_FC_CP_IFL_CAP)
501 		return -EOPNOTSUPP;
502 	info = (void *)get_zeroed_page(GFP_KERNEL);
503 	if (!info)
504 		return -ENOMEM;
505 	r = sthyi_fill(info, &sthyi_rc);
506 	if (r < 0)
507 		goto out;
508 	if (return_code && put_user(sthyi_rc, return_code)) {
509 		r = -EFAULT;
510 		goto out;
511 	}
512 	if (copy_to_user(buffer, info, PAGE_SIZE))
513 		r = -EFAULT;
514 out:
515 	free_page((unsigned long)info);
516 	return r;
517 }
518