xref: /openbmc/linux/arch/s390/kernel/processor.c (revision ab3a560a)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  *  Copyright IBM Corp. 2008
4  *  Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
5  */
6 
7 #define KMSG_COMPONENT "cpu"
8 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9 
10 #include <linux/stop_machine.h>
11 #include <linux/cpufeature.h>
12 #include <linux/bitops.h>
13 #include <linux/kernel.h>
14 #include <linux/random.h>
15 #include <linux/sched/mm.h>
16 #include <linux/init.h>
17 #include <linux/seq_file.h>
18 #include <linux/mm_types.h>
19 #include <linux/delay.h>
20 #include <linux/cpu.h>
21 
22 #include <asm/diag.h>
23 #include <asm/facility.h>
24 #include <asm/elf.h>
25 #include <asm/lowcore.h>
26 #include <asm/param.h>
27 #include <asm/sclp.h>
28 #include <asm/smp.h>
29 
30 unsigned long __read_mostly elf_hwcap;
31 char elf_platform[ELF_PLATFORM_SIZE];
32 
33 struct cpu_info {
34 	unsigned int cpu_mhz_dynamic;
35 	unsigned int cpu_mhz_static;
36 	struct cpuid cpu_id;
37 };
38 
39 static DEFINE_PER_CPU(struct cpu_info, cpu_info);
40 static DEFINE_PER_CPU(int, cpu_relax_retry);
41 
42 static bool machine_has_cpu_mhz;
43 
44 void __init cpu_detect_mhz_feature(void)
45 {
46 	if (test_facility(34) && __ecag(ECAG_CPU_ATTRIBUTE, 0) != -1UL)
47 		machine_has_cpu_mhz = true;
48 }
49 
50 static void update_cpu_mhz(void *arg)
51 {
52 	unsigned long mhz;
53 	struct cpu_info *c;
54 
55 	mhz = __ecag(ECAG_CPU_ATTRIBUTE, 0);
56 	c = this_cpu_ptr(&cpu_info);
57 	c->cpu_mhz_dynamic = mhz >> 32;
58 	c->cpu_mhz_static = mhz & 0xffffffff;
59 }
60 
61 void s390_update_cpu_mhz(void)
62 {
63 	s390_adjust_jiffies();
64 	if (machine_has_cpu_mhz)
65 		on_each_cpu(update_cpu_mhz, NULL, 0);
66 }
67 
68 void notrace stop_machine_yield(const struct cpumask *cpumask)
69 {
70 	int cpu, this_cpu;
71 
72 	this_cpu = smp_processor_id();
73 	if (__this_cpu_inc_return(cpu_relax_retry) >= spin_retry) {
74 		__this_cpu_write(cpu_relax_retry, 0);
75 		cpu = cpumask_next_wrap(this_cpu, cpumask, this_cpu, false);
76 		if (cpu >= nr_cpu_ids)
77 			return;
78 		if (arch_vcpu_is_preempted(cpu))
79 			smp_yield_cpu(cpu);
80 	}
81 }
82 
83 /*
84  * cpu_init - initializes state that is per-CPU.
85  */
86 void cpu_init(void)
87 {
88 	struct cpuid *id = this_cpu_ptr(&cpu_info.cpu_id);
89 
90 	get_cpu_id(id);
91 	if (machine_has_cpu_mhz)
92 		update_cpu_mhz(NULL);
93 	mmgrab(&init_mm);
94 	current->active_mm = &init_mm;
95 	BUG_ON(current->mm);
96 	enter_lazy_tlb(&init_mm, current);
97 }
98 
99 /*
100  * cpu_have_feature - Test CPU features on module initialization
101  */
102 int cpu_have_feature(unsigned int num)
103 {
104 	return elf_hwcap & (1UL << num);
105 }
106 EXPORT_SYMBOL(cpu_have_feature);
107 
108 static void show_facilities(struct seq_file *m)
109 {
110 	unsigned int bit;
111 
112 	seq_puts(m, "facilities      :");
113 	for_each_set_bit_inv(bit, (long *)&stfle_fac_list, MAX_FACILITY_BIT)
114 		seq_printf(m, " %d", bit);
115 	seq_putc(m, '\n');
116 }
117 
118 static void show_cpu_summary(struct seq_file *m, void *v)
119 {
120 	static const char *hwcap_str[] = {
121 		[HWCAP_NR_ESAN3]	= "esan3",
122 		[HWCAP_NR_ZARCH]	= "zarch",
123 		[HWCAP_NR_STFLE]	= "stfle",
124 		[HWCAP_NR_MSA]		= "msa",
125 		[HWCAP_NR_LDISP]	= "ldisp",
126 		[HWCAP_NR_EIMM]		= "eimm",
127 		[HWCAP_NR_DFP]		= "dfp",
128 		[HWCAP_NR_HPAGE]	= "edat",
129 		[HWCAP_NR_ETF3EH]	= "etf3eh",
130 		[HWCAP_NR_HIGH_GPRS]	= "highgprs",
131 		[HWCAP_NR_TE]		= "te",
132 		[HWCAP_NR_VXRS]		= "vx",
133 		[HWCAP_NR_VXRS_BCD]	= "vxd",
134 		[HWCAP_NR_VXRS_EXT]	= "vxe",
135 		[HWCAP_NR_GS]		= "gs",
136 		[HWCAP_NR_VXRS_EXT2]	= "vxe2",
137 		[HWCAP_NR_VXRS_PDE]	= "vxp",
138 		[HWCAP_NR_SORT]		= "sort",
139 		[HWCAP_NR_DFLT]		= "dflt",
140 		[HWCAP_NR_VXRS_PDE2]	= "vxp2",
141 		[HWCAP_NR_NNPA]		= "nnpa",
142 		[HWCAP_NR_PCI_MIO]	= "pcimio",
143 		[HWCAP_NR_SIE]		= "sie",
144 	};
145 	int i, cpu;
146 
147 	BUILD_BUG_ON(ARRAY_SIZE(hwcap_str) != HWCAP_NR_MAX);
148 	seq_printf(m, "vendor_id       : IBM/S390\n"
149 		   "# processors    : %i\n"
150 		   "bogomips per cpu: %lu.%02lu\n",
151 		   num_online_cpus(), loops_per_jiffy/(500000/HZ),
152 		   (loops_per_jiffy/(5000/HZ))%100);
153 	seq_printf(m, "max thread id   : %d\n", smp_cpu_mtid);
154 	seq_puts(m, "features\t: ");
155 	for (i = 0; i < ARRAY_SIZE(hwcap_str); i++)
156 		if (hwcap_str[i] && (elf_hwcap & (1UL << i)))
157 			seq_printf(m, "%s ", hwcap_str[i]);
158 	seq_puts(m, "\n");
159 	show_facilities(m);
160 	show_cacheinfo(m);
161 	for_each_online_cpu(cpu) {
162 		struct cpuid *id = &per_cpu(cpu_info.cpu_id, cpu);
163 
164 		seq_printf(m, "processor %d: "
165 			   "version = %02X,  "
166 			   "identification = %06X,  "
167 			   "machine = %04X\n",
168 			   cpu, id->version, id->ident, id->machine);
169 	}
170 }
171 
172 static int __init setup_hwcaps(void)
173 {
174 	/* instructions named N3, "backported" to esa-mode */
175 	elf_hwcap |= HWCAP_ESAN3;
176 
177 	/* z/Architecture mode active */
178 	elf_hwcap |= HWCAP_ZARCH;
179 
180 	/* store-facility-list-extended */
181 	if (test_facility(7))
182 		elf_hwcap |= HWCAP_STFLE;
183 
184 	/* message-security assist */
185 	if (test_facility(17))
186 		elf_hwcap |= HWCAP_MSA;
187 
188 	/* long-displacement */
189 	if (test_facility(19))
190 		elf_hwcap |= HWCAP_LDISP;
191 
192 	/* extended-immediate */
193 	elf_hwcap |= HWCAP_EIMM;
194 
195 	/* extended-translation facility 3 enhancement */
196 	if (test_facility(22) && test_facility(30))
197 		elf_hwcap |= HWCAP_ETF3EH;
198 
199 	/* decimal floating point & perform floating point operation */
200 	if (test_facility(42) && test_facility(44))
201 		elf_hwcap |= HWCAP_DFP;
202 
203 	/* huge page support */
204 	if (MACHINE_HAS_EDAT1)
205 		elf_hwcap |= HWCAP_HPAGE;
206 
207 	/* 64-bit register support for 31-bit processes */
208 	elf_hwcap |= HWCAP_HIGH_GPRS;
209 
210 	/* transactional execution */
211 	if (MACHINE_HAS_TE)
212 		elf_hwcap |= HWCAP_TE;
213 
214 	/*
215 	 * Vector extension can be disabled with the "novx" parameter.
216 	 * Use MACHINE_HAS_VX instead of facility bit 129.
217 	 */
218 	if (MACHINE_HAS_VX) {
219 		elf_hwcap |= HWCAP_VXRS;
220 		if (test_facility(134))
221 			elf_hwcap |= HWCAP_VXRS_BCD;
222 		if (test_facility(135))
223 			elf_hwcap |= HWCAP_VXRS_EXT;
224 		if (test_facility(148))
225 			elf_hwcap |= HWCAP_VXRS_EXT2;
226 		if (test_facility(152))
227 			elf_hwcap |= HWCAP_VXRS_PDE;
228 		if (test_facility(192))
229 			elf_hwcap |= HWCAP_VXRS_PDE2;
230 	}
231 
232 	if (test_facility(150))
233 		elf_hwcap |= HWCAP_SORT;
234 
235 	if (test_facility(151))
236 		elf_hwcap |= HWCAP_DFLT;
237 
238 	if (test_facility(165))
239 		elf_hwcap |= HWCAP_NNPA;
240 
241 	/* guarded storage */
242 	if (MACHINE_HAS_GS)
243 		elf_hwcap |= HWCAP_GS;
244 
245 	if (MACHINE_HAS_PCI_MIO)
246 		elf_hwcap |= HWCAP_PCI_MIO;
247 
248 	/* virtualization support */
249 	if (sclp.has_sief2)
250 		elf_hwcap |= HWCAP_SIE;
251 
252 	return 0;
253 }
254 arch_initcall(setup_hwcaps);
255 
256 static int __init setup_elf_platform(void)
257 {
258 	struct cpuid cpu_id;
259 
260 	get_cpu_id(&cpu_id);
261 	add_device_randomness(&cpu_id, sizeof(cpu_id));
262 	switch (cpu_id.machine) {
263 	default:	/* Use "z10" as default. */
264 		strcpy(elf_platform, "z10");
265 		break;
266 	case 0x2817:
267 	case 0x2818:
268 		strcpy(elf_platform, "z196");
269 		break;
270 	case 0x2827:
271 	case 0x2828:
272 		strcpy(elf_platform, "zEC12");
273 		break;
274 	case 0x2964:
275 	case 0x2965:
276 		strcpy(elf_platform, "z13");
277 		break;
278 	case 0x3906:
279 	case 0x3907:
280 		strcpy(elf_platform, "z14");
281 		break;
282 	case 0x8561:
283 	case 0x8562:
284 		strcpy(elf_platform, "z15");
285 		break;
286 	}
287 	return 0;
288 }
289 arch_initcall(setup_elf_platform);
290 
291 static void show_cpu_topology(struct seq_file *m, unsigned long n)
292 {
293 #ifdef CONFIG_SCHED_TOPOLOGY
294 	seq_printf(m, "physical id     : %d\n", topology_physical_package_id(n));
295 	seq_printf(m, "core id         : %d\n", topology_core_id(n));
296 	seq_printf(m, "book id         : %d\n", topology_book_id(n));
297 	seq_printf(m, "drawer id       : %d\n", topology_drawer_id(n));
298 	seq_printf(m, "dedicated       : %d\n", topology_cpu_dedicated(n));
299 	seq_printf(m, "address         : %d\n", smp_cpu_get_cpu_address(n));
300 	seq_printf(m, "siblings        : %d\n", cpumask_weight(topology_core_cpumask(n)));
301 	seq_printf(m, "cpu cores       : %d\n", topology_booted_cores(n));
302 #endif /* CONFIG_SCHED_TOPOLOGY */
303 }
304 
305 static void show_cpu_ids(struct seq_file *m, unsigned long n)
306 {
307 	struct cpuid *id = &per_cpu(cpu_info.cpu_id, n);
308 
309 	seq_printf(m, "version         : %02X\n", id->version);
310 	seq_printf(m, "identification  : %06X\n", id->ident);
311 	seq_printf(m, "machine         : %04X\n", id->machine);
312 }
313 
314 static void show_cpu_mhz(struct seq_file *m, unsigned long n)
315 {
316 	struct cpu_info *c = per_cpu_ptr(&cpu_info, n);
317 
318 	if (!machine_has_cpu_mhz)
319 		return;
320 	seq_printf(m, "cpu MHz dynamic : %d\n", c->cpu_mhz_dynamic);
321 	seq_printf(m, "cpu MHz static  : %d\n", c->cpu_mhz_static);
322 }
323 
324 /*
325  * show_cpuinfo - Get information on one CPU for use by procfs.
326  */
327 static int show_cpuinfo(struct seq_file *m, void *v)
328 {
329 	unsigned long n = (unsigned long) v - 1;
330 	unsigned long first = cpumask_first(cpu_online_mask);
331 
332 	if (n == first)
333 		show_cpu_summary(m, v);
334 	seq_printf(m, "\ncpu number      : %ld\n", n);
335 	show_cpu_topology(m, n);
336 	show_cpu_ids(m, n);
337 	show_cpu_mhz(m, n);
338 	return 0;
339 }
340 
341 static inline void *c_update(loff_t *pos)
342 {
343 	if (*pos)
344 		*pos = cpumask_next(*pos - 1, cpu_online_mask);
345 	else
346 		*pos = cpumask_first(cpu_online_mask);
347 	return *pos < nr_cpu_ids ? (void *)*pos + 1 : NULL;
348 }
349 
350 static void *c_start(struct seq_file *m, loff_t *pos)
351 {
352 	cpus_read_lock();
353 	return c_update(pos);
354 }
355 
356 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
357 {
358 	++*pos;
359 	return c_update(pos);
360 }
361 
362 static void c_stop(struct seq_file *m, void *v)
363 {
364 	cpus_read_unlock();
365 }
366 
367 const struct seq_operations cpuinfo_op = {
368 	.start	= c_start,
369 	.next	= c_next,
370 	.stop	= c_stop,
371 	.show	= show_cpuinfo,
372 };
373 
374 int s390_isolate_bp(void)
375 {
376 	if (!test_facility(82))
377 		return -EOPNOTSUPP;
378 	set_thread_flag(TIF_ISOLATE_BP);
379 	return 0;
380 }
381 EXPORT_SYMBOL(s390_isolate_bp);
382 
383 int s390_isolate_bp_guest(void)
384 {
385 	if (!test_facility(82))
386 		return -EOPNOTSUPP;
387 	set_thread_flag(TIF_ISOLATE_BP_GUEST);
388 	return 0;
389 }
390 EXPORT_SYMBOL(s390_isolate_bp_guest);
391