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 
fill_diag(struct sthyi_sctns * sctns)303 static void fill_diag(struct sthyi_sctns *sctns)
304 {
305 	int i, r, pages;
306 	bool this_lpar;
307 	void *diag204_buf;
308 	void *diag224_buf = NULL;
309 	struct diag204_x_info_blk_hdr *ti_hdr;
310 	struct diag204_x_part_block *part_block;
311 	struct diag204_x_phys_block *phys_block;
312 	struct lpar_cpu_inf lpar_inf = {};
313 
314 	/* Errors are handled through the validity bits in the response. */
315 	pages = diag204((unsigned long)DIAG204_SUBC_RSI |
316 			(unsigned long)DIAG204_INFO_EXT, 0, NULL);
317 	if (pages <= 0)
318 		return;
319 
320 	diag204_buf = vmalloc(array_size(pages, PAGE_SIZE));
321 	if (!diag204_buf)
322 		return;
323 
324 	r = diag204((unsigned long)DIAG204_SUBC_STIB7 |
325 		    (unsigned long)DIAG204_INFO_EXT, pages, diag204_buf);
326 	if (r < 0)
327 		goto out;
328 
329 	diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
330 	if (!diag224_buf || diag224(diag224_buf))
331 		goto out;
332 
333 	ti_hdr = diag204_buf;
334 	part_block = diag204_buf + sizeof(*ti_hdr);
335 
336 	for (i = 0; i < ti_hdr->npar; i++) {
337 		/*
338 		 * For the calling lpar we also need to get the cpu
339 		 * caps and weights. The time information block header
340 		 * specifies the offset to the partition block of the
341 		 * caller lpar, so we know when we process its data.
342 		 */
343 		this_lpar = (void *)part_block - diag204_buf == ti_hdr->this_part;
344 		part_block = lpar_cpu_inf(&lpar_inf, this_lpar, diag224_buf,
345 					  part_block);
346 	}
347 
348 	phys_block = (struct diag204_x_phys_block *)part_block;
349 	part_block = diag204_buf + ti_hdr->this_part;
350 	if (part_block->hdr.mtid)
351 		sctns->par.infpflg1 = PAR_MT_EN;
352 
353 	sctns->par.infpval1 |= PAR_GRP_VLD;
354 	sctns->par.infplgcp = scale_cap(lpar_inf.cp.lpar_grp_cap);
355 	sctns->par.infplgif = scale_cap(lpar_inf.ifl.lpar_grp_cap);
356 	memcpy(sctns->par.infplgnm, part_block->hdr.hardware_group_name,
357 	       sizeof(sctns->par.infplgnm));
358 
359 	sctns->par.infpscps = lpar_inf.cp.cpu_num_shd;
360 	sctns->par.infpdcps = lpar_inf.cp.cpu_num_ded;
361 	sctns->par.infpsifl = lpar_inf.ifl.cpu_num_shd;
362 	sctns->par.infpdifl = lpar_inf.ifl.cpu_num_ded;
363 	sctns->par.infpval1 |= PAR_PCNT_VLD;
364 
365 	sctns->par.infpabcp = scale_cap(lpar_inf.cp.lpar_cap);
366 	sctns->par.infpabif = scale_cap(lpar_inf.ifl.lpar_cap);
367 	sctns->par.infpval1 |= PAR_ABS_VLD;
368 
369 	/*
370 	 * Everything below needs global performance data to be
371 	 * meaningful.
372 	 */
373 	if (!(ti_hdr->flags & DIAG204_LPAR_PHYS_FLG)) {
374 		sctns->hdr.infhflg1 |= HDR_PERF_UNAV;
375 		goto out;
376 	}
377 
378 	fill_diag_mac(sctns, phys_block, diag224_buf);
379 
380 	if (lpar_inf.cp.lpar_weight) {
381 		sctns->par.infpwbcp = sctns->mac.infmscps * 0x10000 *
382 			lpar_inf.cp.lpar_weight / lpar_inf.cp.all_weight;
383 	}
384 
385 	if (lpar_inf.ifl.lpar_weight) {
386 		sctns->par.infpwbif = sctns->mac.infmsifl * 0x10000 *
387 			lpar_inf.ifl.lpar_weight / lpar_inf.ifl.all_weight;
388 	}
389 	sctns->par.infpval1 |= PAR_WGHT_VLD;
390 
391 out:
392 	free_page((unsigned long)diag224_buf);
393 	vfree(diag204_buf);
394 }
395 
sthyi(u64 vaddr,u64 * rc)396 static int sthyi(u64 vaddr, u64 *rc)
397 {
398 	union register_pair r1 = { .even = 0, }; /* subcode */
399 	union register_pair r2 = { .even = vaddr, };
400 	int cc;
401 
402 	asm volatile(
403 		".insn   rre,0xB2560000,%[r1],%[r2]\n"
404 		"ipm     %[cc]\n"
405 		"srl     %[cc],28\n"
406 		: [cc] "=&d" (cc), [r2] "+&d" (r2.pair)
407 		: [r1] "d" (r1.pair)
408 		: "memory", "cc");
409 	*rc = r2.odd;
410 	return cc;
411 }
412 
fill_dst(void * dst,u64 * rc)413 static int fill_dst(void *dst, u64 *rc)
414 {
415 	struct sthyi_sctns *sctns = (struct sthyi_sctns *)dst;
416 
417 	/*
418 	 * If the facility is on, we don't want to emulate the instruction.
419 	 * We ask the hypervisor to provide the data.
420 	 */
421 	if (test_facility(74))
422 		return sthyi((u64)dst, rc);
423 
424 	fill_hdr(sctns);
425 	fill_stsi(sctns);
426 	fill_diag(sctns);
427 	*rc = 0;
428 	return 0;
429 }
430 
sthyi_init_cache(void)431 static int sthyi_init_cache(void)
432 {
433 	if (sthyi_cache.info)
434 		return 0;
435 	sthyi_cache.info = (void *)get_zeroed_page(GFP_KERNEL);
436 	if (!sthyi_cache.info)
437 		return -ENOMEM;
438 	sthyi_cache.end = jiffies - 1; /* expired */
439 	return 0;
440 }
441 
sthyi_update_cache(u64 * rc)442 static int sthyi_update_cache(u64 *rc)
443 {
444 	int r;
445 
446 	memset(sthyi_cache.info, 0, PAGE_SIZE);
447 	r = fill_dst(sthyi_cache.info, rc);
448 	if (r)
449 		return r;
450 	sthyi_cache.end = jiffies + CACHE_VALID_JIFFIES;
451 	return r;
452 }
453 
454 /*
455  * sthyi_fill - Fill page with data returned by the STHYI instruction
456  *
457  * @dst: Pointer to zeroed page
458  * @rc:  Pointer for storing the return code of the instruction
459  *
460  * Fills the destination with system information returned by the STHYI
461  * instruction. The data is generated by emulation or execution of STHYI,
462  * if available. The return value is the condition code that would be
463  * returned, the rc parameter is the return code which is passed in
464  * register R2 + 1.
465  */
sthyi_fill(void * dst,u64 * rc)466 int sthyi_fill(void *dst, u64 *rc)
467 {
468 	int r;
469 
470 	mutex_lock(&sthyi_mutex);
471 	r = sthyi_init_cache();
472 	if (r)
473 		goto out;
474 
475 	if (time_is_before_jiffies(sthyi_cache.end)) {
476 		/* cache expired */
477 		r = sthyi_update_cache(rc);
478 		if (r)
479 			goto out;
480 	}
481 	*rc = 0;
482 	memcpy(dst, sthyi_cache.info, PAGE_SIZE);
483 out:
484 	mutex_unlock(&sthyi_mutex);
485 	return r;
486 }
487 EXPORT_SYMBOL_GPL(sthyi_fill);
488 
SYSCALL_DEFINE4(s390_sthyi,unsigned long,function_code,void __user *,buffer,u64 __user *,return_code,unsigned long,flags)489 SYSCALL_DEFINE4(s390_sthyi, unsigned long, function_code, void __user *, buffer,
490 		u64 __user *, return_code, unsigned long, flags)
491 {
492 	u64 sthyi_rc;
493 	void *info;
494 	int r;
495 
496 	if (flags)
497 		return -EINVAL;
498 	if (function_code != STHYI_FC_CP_IFL_CAP)
499 		return -EOPNOTSUPP;
500 	info = (void *)get_zeroed_page(GFP_KERNEL);
501 	if (!info)
502 		return -ENOMEM;
503 	r = sthyi_fill(info, &sthyi_rc);
504 	if (r < 0)
505 		goto out;
506 	if (return_code && put_user(sthyi_rc, return_code)) {
507 		r = -EFAULT;
508 		goto out;
509 	}
510 	if (copy_to_user(buffer, info, PAGE_SIZE))
511 		r = -EFAULT;
512 out:
513 	free_page((unsigned long)info);
514 	return r;
515 }
516