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  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 <asm/asm.h>
 21#include "entry.h"
 22
 23#define DED_WEIGHT 0xffff
 24/*
 25 * CP and IFL as EBCDIC strings, SP/0x40 determines the end of string
 26 * as they are justified with spaces.
 27 */
 28#define CP  0xc3d7404040404040UL
 29#define IFL 0xc9c6d34040404040UL
 30
 31enum hdr_flags {
 32	HDR_NOT_LPAR   = 0x10,
 33	HDR_STACK_INCM = 0x20,
 34	HDR_STSI_UNAV  = 0x40,
 35	HDR_PERF_UNAV  = 0x80,
 36};
 37
 38enum mac_validity {
 39	MAC_NAME_VLD = 0x20,
 40	MAC_ID_VLD   = 0x40,
 41	MAC_CNT_VLD  = 0x80,
 42};
 43
 44enum par_flag {
 45	PAR_MT_EN = 0x80,
 46};
 47
 48enum par_validity {
 49	PAR_GRP_VLD  = 0x08,
 50	PAR_ID_VLD   = 0x10,
 51	PAR_ABS_VLD  = 0x20,
 52	PAR_WGHT_VLD = 0x40,
 53	PAR_PCNT_VLD  = 0x80,
 54};
 55
 56struct hdr_sctn {
 57	u8 infhflg1;
 58	u8 infhflg2; /* reserved */
 59	u8 infhval1; /* reserved */
 60	u8 infhval2; /* reserved */
 61	u8 reserved[3];
 62	u8 infhygct;
 63	u16 infhtotl;
 64	u16 infhdln;
 65	u16 infmoff;
 66	u16 infmlen;
 67	u16 infpoff;
 68	u16 infplen;
 69	u16 infhoff1;
 70	u16 infhlen1;
 71	u16 infgoff1;
 72	u16 infglen1;
 73	u16 infhoff2;
 74	u16 infhlen2;
 75	u16 infgoff2;
 76	u16 infglen2;
 77	u16 infhoff3;
 78	u16 infhlen3;
 79	u16 infgoff3;
 80	u16 infglen3;
 81	u8 reserved2[4];
 82} __packed;
 83
 84struct mac_sctn {
 85	u8 infmflg1; /* reserved */
 86	u8 infmflg2; /* reserved */
 87	u8 infmval1;
 88	u8 infmval2; /* reserved */
 89	u16 infmscps;
 90	u16 infmdcps;
 91	u16 infmsifl;
 92	u16 infmdifl;
 93	char infmname[8];
 94	char infmtype[4];
 95	char infmmanu[16];
 96	char infmseq[16];
 97	char infmpman[4];
 98	u8 reserved[4];
 99} __packed;
100
101struct par_sctn {
102	u8 infpflg1;
103	u8 infpflg2; /* reserved */
104	u8 infpval1;
105	u8 infpval2; /* reserved */
106	u16 infppnum;
107	u16 infpscps;
108	u16 infpdcps;
109	u16 infpsifl;
110	u16 infpdifl;
111	u16 reserved;
112	char infppnam[8];
113	u32 infpwbcp;
114	u32 infpabcp;
115	u32 infpwbif;
116	u32 infpabif;
117	char infplgnm[8];
118	u32 infplgcp;
119	u32 infplgif;
120} __packed;
121
122struct sthyi_sctns {
123	struct hdr_sctn hdr;
124	struct mac_sctn mac;
125	struct par_sctn par;
126} __packed;
127
128struct cpu_inf {
129	u64 lpar_cap;
130	u64 lpar_grp_cap;
131	u64 lpar_weight;
132	u64 all_weight;
133	int cpu_num_ded;
134	int cpu_num_shd;
135};
136
137struct lpar_cpu_inf {
138	struct cpu_inf cp;
139	struct cpu_inf ifl;
140};
141
142/*
143 * STHYI requires extensive locking in the higher hypervisors
144 * and is very computational/memory expensive. Therefore we
145 * cache the retrieved data whose valid period is 1s.
146 */
147#define CACHE_VALID_JIFFIES	HZ
148
149struct sthyi_info {
150	void *info;
151	unsigned long end;
152};
153
154static DEFINE_MUTEX(sthyi_mutex);
155static struct sthyi_info sthyi_cache;
156
157static inline u64 cpu_id(u8 ctidx, void *diag224_buf)
158{
159	return *((u64 *)(diag224_buf + (ctidx + 1) * DIAG204_CPU_NAME_LEN));
160}
161
162/*
163 * Scales the cpu capping from the lpar range to the one expected in
164 * sthyi data.
165 *
166 * diag204 reports a cap in hundredths of processor units.
167 * z/VM's range for one core is 0 - 0x10000.
168 */
169static u32 scale_cap(u32 in)
170{
171	return (0x10000 * in) / 100;
172}
173
174static void fill_hdr(struct sthyi_sctns *sctns)
175{
176	sctns->hdr.infhdln = sizeof(sctns->hdr);
177	sctns->hdr.infmoff = sizeof(sctns->hdr);
178	sctns->hdr.infmlen = sizeof(sctns->mac);
179	sctns->hdr.infplen = sizeof(sctns->par);
180	sctns->hdr.infpoff = sctns->hdr.infhdln + sctns->hdr.infmlen;
181	sctns->hdr.infhtotl = sctns->hdr.infpoff + sctns->hdr.infplen;
182}
183
184static void fill_stsi_mac(struct sthyi_sctns *sctns,
185			  struct sysinfo_1_1_1 *sysinfo)
186{
187	sclp_ocf_cpc_name_copy(sctns->mac.infmname);
188	if (*(u64 *)sctns->mac.infmname != 0)
189		sctns->mac.infmval1 |= MAC_NAME_VLD;
190
191	if (stsi(sysinfo, 1, 1, 1))
192		return;
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;
200}
201
202static 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
214static 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
229static 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. */
255static 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
304static void *diag204_get_data(bool diag204_allow_busy)
305{
306	unsigned long subcode;
307	void *diag204_buf;
308	int pages, rc;
309
310	subcode = DIAG204_SUBC_RSI;
311	subcode |= DIAG204_INFO_EXT;
312	pages = diag204(subcode, 0, NULL);
313	if (pages < 0)
314		return ERR_PTR(pages);
315	if (pages == 0)
316		return ERR_PTR(-ENODATA);
317	diag204_buf = __vmalloc_node(array_size(pages, PAGE_SIZE),
318				     PAGE_SIZE, GFP_KERNEL, NUMA_NO_NODE,
319				     __builtin_return_address(0));
320	if (!diag204_buf)
321		return ERR_PTR(-ENOMEM);
322	subcode = DIAG204_SUBC_STIB7;
323	subcode |= DIAG204_INFO_EXT;
324	if (diag204_has_bif() && diag204_allow_busy)
325		subcode |= DIAG204_BIF_BIT;
326	rc = diag204(subcode, pages, diag204_buf);
327	if (rc < 0) {
328		vfree(diag204_buf);
329		return ERR_PTR(rc);
330	}
331	return diag204_buf;
332}
333
334static bool is_diag204_cached(struct sthyi_sctns *sctns)
335{
336	/*
337	 * Check if validity bits are set when diag204 data
338	 * is gathered.
339	 */
340	if (sctns->par.infpval1)
341		return true;
342	return false;
343}
344
345static void fill_diag(struct sthyi_sctns *sctns, void *diag204_buf)
346{
347	int i;
348	bool this_lpar;
349	void *diag224_buf = NULL;
350	struct diag204_x_info_blk_hdr *ti_hdr;
351	struct diag204_x_part_block *part_block;
352	struct diag204_x_phys_block *phys_block;
353	struct lpar_cpu_inf lpar_inf = {};
354
355	diag224_buf = (void *)__get_free_page(GFP_KERNEL | GFP_DMA);
356	if (!diag224_buf || diag224(diag224_buf))
357		goto out;
358
359	ti_hdr = diag204_buf;
360	part_block = diag204_buf + sizeof(*ti_hdr);
361
362	for (i = 0; i < ti_hdr->npar; i++) {
363		/*
364		 * For the calling lpar we also need to get the cpu
365		 * caps and weights. The time information block header
366		 * specifies the offset to the partition block of the
367		 * caller lpar, so we know when we process its data.
368		 */
369		this_lpar = (void *)part_block - diag204_buf == ti_hdr->this_part;
370		part_block = lpar_cpu_inf(&lpar_inf, this_lpar, diag224_buf,
371					  part_block);
372	}
373
374	phys_block = (struct diag204_x_phys_block *)part_block;
375	part_block = diag204_buf + ti_hdr->this_part;
376	if (part_block->hdr.mtid)
377		sctns->par.infpflg1 = PAR_MT_EN;
378
379	sctns->par.infpval1 |= PAR_GRP_VLD;
380	sctns->par.infplgcp = scale_cap(lpar_inf.cp.lpar_grp_cap);
381	sctns->par.infplgif = scale_cap(lpar_inf.ifl.lpar_grp_cap);
382	memcpy(sctns->par.infplgnm, part_block->hdr.hardware_group_name,
383	       sizeof(sctns->par.infplgnm));
384
385	sctns->par.infpscps = lpar_inf.cp.cpu_num_shd;
386	sctns->par.infpdcps = lpar_inf.cp.cpu_num_ded;
387	sctns->par.infpsifl = lpar_inf.ifl.cpu_num_shd;
388	sctns->par.infpdifl = lpar_inf.ifl.cpu_num_ded;
389	sctns->par.infpval1 |= PAR_PCNT_VLD;
390
391	sctns->par.infpabcp = scale_cap(lpar_inf.cp.lpar_cap);
392	sctns->par.infpabif = scale_cap(lpar_inf.ifl.lpar_cap);
393	sctns->par.infpval1 |= PAR_ABS_VLD;
394
395	/*
396	 * Everything below needs global performance data to be
397	 * meaningful.
398	 */
399	if (!(ti_hdr->flags & DIAG204_LPAR_PHYS_FLG)) {
400		sctns->hdr.infhflg1 |= HDR_PERF_UNAV;
401		goto out;
402	}
403
404	fill_diag_mac(sctns, phys_block, diag224_buf);
405
406	if (lpar_inf.cp.lpar_weight) {
407		sctns->par.infpwbcp = sctns->mac.infmscps * 0x10000 *
408			lpar_inf.cp.lpar_weight / lpar_inf.cp.all_weight;
409	}
410
411	if (lpar_inf.ifl.lpar_weight) {
412		sctns->par.infpwbif = sctns->mac.infmsifl * 0x10000 *
413			lpar_inf.ifl.lpar_weight / lpar_inf.ifl.all_weight;
414	}
415	sctns->par.infpval1 |= PAR_WGHT_VLD;
416
417out:
418	free_page((unsigned long)diag224_buf);
419}
420
421static int sthyi(u64 vaddr, u64 *rc)
422{
423	union register_pair r1 = { .even = 0, }; /* subcode */
424	union register_pair r2 = { .even = vaddr, };
425	int cc;
426
427	asm volatile(
428		".insn   rre,0xB2560000,%[r1],%[r2]\n"
429		CC_IPM(cc)
430		: CC_OUT(cc, cc), [r2] "+&d" (r2.pair)
431		: [r1] "d" (r1.pair)
432		: CC_CLOBBER_LIST("memory"));
433	*rc = r2.odd;
434	return CC_TRANSFORM(cc);
435}
436
437static 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
467static 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
478static 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 */
505int 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);
522out:
523	mutex_unlock(&sthyi_mutex);
524	return r;
525}
526EXPORT_SYMBOL_GPL(sthyi_fill);
527
528SYSCALL_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;
551out:
552	free_page((unsigned long)info);
553	return r;
554}