1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PowerNV setup code.
4  *
5  * Copyright 2011 IBM Corp.
6  */
7 
8 #undef DEBUG
9 
10 #include <linux/cpu.h>
11 #include <linux/errno.h>
12 #include <linux/sched.h>
13 #include <linux/kernel.h>
14 #include <linux/tty.h>
15 #include <linux/reboot.h>
16 #include <linux/init.h>
17 #include <linux/console.h>
18 #include <linux/delay.h>
19 #include <linux/irq.h>
20 #include <linux/seq_buf.h>
21 #include <linux/seq_file.h>
22 #include <linux/of.h>
23 #include <linux/of_fdt.h>
24 #include <linux/interrupt.h>
25 #include <linux/bug.h>
26 #include <linux/pci.h>
27 #include <linux/cpufreq.h>
28 #include <linux/memblock.h>
29 
30 #include <asm/machdep.h>
31 #include <asm/firmware.h>
32 #include <asm/xics.h>
33 #include <asm/xive.h>
34 #include <asm/opal.h>
35 #include <asm/kexec.h>
36 #include <asm/smp.h>
37 #include <asm/tm.h>
38 #include <asm/setup.h>
39 #include <asm/security_features.h>
40 
41 #include "powernv.h"
42 
43 
fw_feature_is(const char * state,const char * name,struct device_node * fw_features)44 static bool __init fw_feature_is(const char *state, const char *name,
45 			  struct device_node *fw_features)
46 {
47 	struct device_node *np;
48 	bool rc = false;
49 
50 	np = of_get_child_by_name(fw_features, name);
51 	if (np) {
52 		rc = of_property_read_bool(np, state);
53 		of_node_put(np);
54 	}
55 
56 	return rc;
57 }
58 
init_fw_feat_flags(struct device_node * np)59 static void __init init_fw_feat_flags(struct device_node *np)
60 {
61 	if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np))
62 		security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
63 
64 	if (fw_feature_is("enabled", "fw-bcctrl-serialized", np))
65 		security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
66 
67 	if (fw_feature_is("enabled", "inst-l1d-flush-ori30,30,0", np))
68 		security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
69 
70 	if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np))
71 		security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
72 
73 	if (fw_feature_is("enabled", "fw-l1d-thread-split", np))
74 		security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
75 
76 	if (fw_feature_is("enabled", "fw-count-cache-disabled", np))
77 		security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
78 
79 	if (fw_feature_is("enabled", "fw-count-cache-flush-bcctr2,0,0", np))
80 		security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST);
81 
82 	if (fw_feature_is("enabled", "needs-count-cache-flush-on-context-switch", np))
83 		security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE);
84 
85 	/*
86 	 * The features below are enabled by default, so we instead look to see
87 	 * if firmware has *disabled* them, and clear them if so.
88 	 */
89 	if (fw_feature_is("disabled", "speculation-policy-favor-security", np))
90 		security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
91 
92 	if (fw_feature_is("disabled", "needs-l1d-flush-msr-pr-0-to-1", np))
93 		security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
94 
95 	if (fw_feature_is("disabled", "needs-l1d-flush-msr-hv-1-to-0", np))
96 		security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
97 
98 	if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np))
99 		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
100 
101 	if (fw_feature_is("enabled", "no-need-l1d-flush-msr-pr-1-to-0", np))
102 		security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
103 
104 	if (fw_feature_is("enabled", "no-need-l1d-flush-kernel-on-user-access", np))
105 		security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
106 
107 	if (fw_feature_is("enabled", "no-need-store-drain-on-priv-state-switch", np))
108 		security_ftr_clear(SEC_FTR_STF_BARRIER);
109 }
110 
pnv_setup_security_mitigations(void)111 static void __init pnv_setup_security_mitigations(void)
112 {
113 	struct device_node *np, *fw_features;
114 	enum l1d_flush_type type;
115 	bool enable;
116 
117 	/* Default to fallback in case fw-features are not available */
118 	type = L1D_FLUSH_FALLBACK;
119 
120 	np = of_find_node_by_name(NULL, "ibm,opal");
121 	fw_features = of_get_child_by_name(np, "fw-features");
122 	of_node_put(np);
123 
124 	if (fw_features) {
125 		init_fw_feat_flags(fw_features);
126 		of_node_put(fw_features);
127 
128 		if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
129 			type = L1D_FLUSH_MTTRIG;
130 
131 		if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
132 			type = L1D_FLUSH_ORI;
133 	}
134 
135 	/*
136 	 * The issues addressed by the entry and uaccess flush don't affect P7
137 	 * or P8, so on bare metal disable them explicitly in case firmware does
138 	 * not include the features to disable them. POWER9 and newer processors
139 	 * should have the appropriate firmware flags.
140 	 */
141 	if (pvr_version_is(PVR_POWER7) || pvr_version_is(PVR_POWER7p) ||
142 	    pvr_version_is(PVR_POWER8E) || pvr_version_is(PVR_POWER8NVL) ||
143 	    pvr_version_is(PVR_POWER8)) {
144 		security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
145 		security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
146 	}
147 
148 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
149 		 (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
150 		  security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
151 
152 	setup_rfi_flush(type, enable);
153 	setup_count_cache_flush();
154 
155 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
156 		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
157 	setup_entry_flush(enable);
158 
159 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
160 		 security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
161 	setup_uaccess_flush(enable);
162 
163 	setup_stf_barrier();
164 }
165 
pnv_check_guarded_cores(void)166 static void __init pnv_check_guarded_cores(void)
167 {
168 	struct device_node *dn;
169 	int bad_count = 0;
170 
171 	for_each_node_by_type(dn, "cpu") {
172 		if (of_property_match_string(dn, "status", "bad") >= 0)
173 			bad_count++;
174 	}
175 
176 	if (bad_count) {
177 		printk("  _     _______________\n");
178 		pr_cont(" | |   /               \\\n");
179 		pr_cont(" | |   |    WARNING!   |\n");
180 		pr_cont(" | |   |               |\n");
181 		pr_cont(" | |   | It looks like |\n");
182 		pr_cont(" |_|   |  you have %*d |\n", 3, bad_count);
183 		pr_cont("  _    | guarded cores |\n");
184 		pr_cont(" (_)   \\_______________/\n");
185 	}
186 }
187 
pnv_setup_arch(void)188 static void __init pnv_setup_arch(void)
189 {
190 	set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
191 
192 	pnv_setup_security_mitigations();
193 
194 	/* Initialize SMP */
195 	pnv_smp_init();
196 
197 	/* Setup RTC and NVRAM callbacks */
198 	if (firmware_has_feature(FW_FEATURE_OPAL))
199 		opal_nvram_init();
200 
201 	/* Enable NAP mode */
202 	powersave_nap = 1;
203 
204 	pnv_check_guarded_cores();
205 
206 	/* XXX PMCS */
207 
208 	pnv_rng_init();
209 }
210 
pnv_add_hw_description(void)211 static void __init pnv_add_hw_description(void)
212 {
213 	struct device_node *dn;
214 	const char *s;
215 
216 	dn = of_find_node_by_path("/ibm,opal/firmware");
217 	if (!dn)
218 		return;
219 
220 	if (of_property_read_string(dn, "version", &s) == 0 ||
221 	    of_property_read_string(dn, "git-id", &s) == 0)
222 		seq_buf_printf(&ppc_hw_desc, "opal:%s ", s);
223 
224 	if (of_property_read_string(dn, "mi-version", &s) == 0)
225 		seq_buf_printf(&ppc_hw_desc, "mi:%s ", s);
226 
227 	of_node_put(dn);
228 }
229 
pnv_init(void)230 static void __init pnv_init(void)
231 {
232 	pnv_add_hw_description();
233 
234 	/*
235 	 * Initialize the LPC bus now so that legacy serial
236 	 * ports can be found on it
237 	 */
238 	opal_lpc_init();
239 
240 #ifdef CONFIG_HVC_OPAL
241 	if (firmware_has_feature(FW_FEATURE_OPAL))
242 		hvc_opal_init_early();
243 	else
244 #endif
245 		add_preferred_console("hvc", 0, NULL);
246 
247 #ifdef CONFIG_PPC_64S_HASH_MMU
248 	if (!radix_enabled()) {
249 		size_t size = sizeof(struct slb_entry) * mmu_slb_size;
250 		int i;
251 
252 		/* Allocate per cpu area to save old slb contents during MCE */
253 		for_each_possible_cpu(i) {
254 			paca_ptrs[i]->mce_faulty_slbs =
255 					memblock_alloc_node(size,
256 						__alignof__(struct slb_entry),
257 						cpu_to_node(i));
258 		}
259 	}
260 #endif
261 }
262 
pnv_init_IRQ(void)263 static void __init pnv_init_IRQ(void)
264 {
265 	/* Try using a XIVE if available, otherwise use a XICS */
266 	if (!xive_native_init())
267 		xics_init();
268 
269 	WARN_ON(!ppc_md.get_irq);
270 }
271 
pnv_show_cpuinfo(struct seq_file * m)272 static void pnv_show_cpuinfo(struct seq_file *m)
273 {
274 	struct device_node *root;
275 	const char *model = "";
276 
277 	root = of_find_node_by_path("/");
278 	if (root)
279 		model = of_get_property(root, "model", NULL);
280 	seq_printf(m, "machine\t\t: PowerNV %s\n", model);
281 	if (firmware_has_feature(FW_FEATURE_OPAL))
282 		seq_printf(m, "firmware\t: OPAL\n");
283 	else
284 		seq_printf(m, "firmware\t: BML\n");
285 	of_node_put(root);
286 	if (radix_enabled())
287 		seq_printf(m, "MMU\t\t: Radix\n");
288 	else
289 		seq_printf(m, "MMU\t\t: Hash\n");
290 }
291 
pnv_prepare_going_down(void)292 static void pnv_prepare_going_down(void)
293 {
294 	/*
295 	 * Disable all notifiers from OPAL, we can't
296 	 * service interrupts anymore anyway
297 	 */
298 	opal_event_shutdown();
299 
300 	/* Print flash update message if one is scheduled. */
301 	opal_flash_update_print_message();
302 
303 	smp_send_stop();
304 
305 	hard_irq_disable();
306 }
307 
pnv_restart(char * cmd)308 static void  __noreturn pnv_restart(char *cmd)
309 {
310 	long rc;
311 
312 	pnv_prepare_going_down();
313 
314 	do {
315 		if (!cmd || !strlen(cmd))
316 			rc = opal_cec_reboot();
317 		else if (strcmp(cmd, "full") == 0)
318 			rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
319 		else if (strcmp(cmd, "mpipl") == 0)
320 			rc = opal_cec_reboot2(OPAL_REBOOT_MPIPL, NULL);
321 		else if (strcmp(cmd, "error") == 0)
322 			rc = opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR, NULL);
323 		else if (strcmp(cmd, "fast") == 0)
324 			rc = opal_cec_reboot2(OPAL_REBOOT_FAST, NULL);
325 		else
326 			rc = OPAL_UNSUPPORTED;
327 
328 		if (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
329 			/* Opal is busy wait for some time and retry */
330 			opal_poll_events(NULL);
331 			mdelay(10);
332 
333 		} else	if (cmd && rc) {
334 			/* Unknown error while issuing reboot */
335 			if (rc == OPAL_UNSUPPORTED)
336 				pr_err("Unsupported '%s' reboot.\n", cmd);
337 			else
338 				pr_err("Unable to issue '%s' reboot. Err=%ld\n",
339 				       cmd, rc);
340 			pr_info("Forcing a cec-reboot\n");
341 			cmd = NULL;
342 			rc = OPAL_BUSY;
343 
344 		} else if (rc != OPAL_SUCCESS) {
345 			/* Unknown error while issuing cec-reboot */
346 			pr_err("Unable to reboot. Err=%ld\n", rc);
347 		}
348 
349 	} while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT);
350 
351 	for (;;)
352 		opal_poll_events(NULL);
353 }
354 
pnv_power_off(void)355 static void __noreturn pnv_power_off(void)
356 {
357 	long rc = OPAL_BUSY;
358 
359 	pnv_prepare_going_down();
360 
361 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
362 		rc = opal_cec_power_down(0);
363 		if (rc == OPAL_BUSY_EVENT)
364 			opal_poll_events(NULL);
365 		else
366 			mdelay(10);
367 	}
368 	for (;;)
369 		opal_poll_events(NULL);
370 }
371 
pnv_halt(void)372 static void __noreturn pnv_halt(void)
373 {
374 	pnv_power_off();
375 }
376 
pnv_progress(char * s,unsigned short hex)377 static void pnv_progress(char *s, unsigned short hex)
378 {
379 }
380 
pnv_shutdown(void)381 static void pnv_shutdown(void)
382 {
383 	/* Let the PCI code clear up IODA tables */
384 	pnv_pci_shutdown();
385 
386 	/*
387 	 * Stop OPAL activity: Unregister all OPAL interrupts so they
388 	 * don't fire up while we kexec and make sure all potentially
389 	 * DMA'ing ops are complete (such as dump retrieval).
390 	 */
391 	opal_shutdown();
392 }
393 
394 #ifdef CONFIG_KEXEC_CORE
pnv_kexec_wait_secondaries_down(void)395 static void pnv_kexec_wait_secondaries_down(void)
396 {
397 	int my_cpu, i, notified = -1;
398 
399 	my_cpu = get_cpu();
400 
401 	for_each_online_cpu(i) {
402 		uint8_t status;
403 		int64_t rc, timeout = 1000;
404 
405 		if (i == my_cpu)
406 			continue;
407 
408 		for (;;) {
409 			rc = opal_query_cpu_status(get_hard_smp_processor_id(i),
410 						   &status);
411 			if (rc != OPAL_SUCCESS || status != OPAL_THREAD_STARTED)
412 				break;
413 			barrier();
414 			if (i != notified) {
415 				printk(KERN_INFO "kexec: waiting for cpu %d "
416 				       "(physical %d) to enter OPAL\n",
417 				       i, paca_ptrs[i]->hw_cpu_id);
418 				notified = i;
419 			}
420 
421 			/*
422 			 * On crash secondaries might be unreachable or hung,
423 			 * so timeout if we've waited too long
424 			 * */
425 			mdelay(1);
426 			if (timeout-- == 0) {
427 				printk(KERN_ERR "kexec: timed out waiting for "
428 				       "cpu %d (physical %d) to enter OPAL\n",
429 				       i, paca_ptrs[i]->hw_cpu_id);
430 				break;
431 			}
432 		}
433 	}
434 }
435 
pnv_kexec_cpu_down(int crash_shutdown,int secondary)436 static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
437 {
438 	u64 reinit_flags;
439 
440 	if (xive_enabled())
441 		xive_teardown_cpu();
442 	else
443 		xics_kexec_teardown_cpu(secondary);
444 
445 	/* On OPAL, we return all CPUs to firmware */
446 	if (!firmware_has_feature(FW_FEATURE_OPAL))
447 		return;
448 
449 	if (secondary) {
450 		/* Return secondary CPUs to firmware on OPAL v3 */
451 		mb();
452 		get_paca()->kexec_state = KEXEC_STATE_REAL_MODE;
453 		mb();
454 
455 		/* Return the CPU to OPAL */
456 		opal_return_cpu();
457 	} else {
458 		/* Primary waits for the secondaries to have reached OPAL */
459 		pnv_kexec_wait_secondaries_down();
460 
461 		/* Switch XIVE back to emulation mode */
462 		if (xive_enabled())
463 			xive_shutdown();
464 
465 		/*
466 		 * We might be running as little-endian - now that interrupts
467 		 * are disabled, reset the HILE bit to big-endian so we don't
468 		 * take interrupts in the wrong endian later
469 		 *
470 		 * We reinit to enable both radix and hash on P9 to ensure
471 		 * the mode used by the next kernel is always supported.
472 		 */
473 		reinit_flags = OPAL_REINIT_CPUS_HILE_BE;
474 		if (cpu_has_feature(CPU_FTR_ARCH_300))
475 			reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX |
476 				OPAL_REINIT_CPUS_MMU_HASH;
477 		opal_reinit_cpus(reinit_flags);
478 	}
479 }
480 #endif /* CONFIG_KEXEC_CORE */
481 
482 #ifdef CONFIG_MEMORY_HOTPLUG
pnv_memory_block_size(void)483 static unsigned long pnv_memory_block_size(void)
484 {
485 	return memory_block_size;
486 }
487 #endif
488 
pnv_setup_machdep_opal(void)489 static void __init pnv_setup_machdep_opal(void)
490 {
491 	ppc_md.get_boot_time = opal_get_boot_time;
492 	ppc_md.restart = pnv_restart;
493 	pm_power_off = pnv_power_off;
494 	ppc_md.halt = pnv_halt;
495 	/* ppc_md.system_reset_exception gets filled in by pnv_smp_init() */
496 	ppc_md.machine_check_exception = opal_machine_check;
497 	ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
498 	if (opal_check_token(OPAL_HANDLE_HMI2))
499 		ppc_md.hmi_exception_early = opal_hmi_exception_early2;
500 	else
501 		ppc_md.hmi_exception_early = opal_hmi_exception_early;
502 	ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
503 }
504 
pnv_probe(void)505 static int __init pnv_probe(void)
506 {
507 	if (firmware_has_feature(FW_FEATURE_OPAL))
508 		pnv_setup_machdep_opal();
509 
510 	pr_debug("PowerNV detected !\n");
511 
512 	pnv_init();
513 
514 	return 1;
515 }
516 
517 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
pnv_tm_init(void)518 void __init pnv_tm_init(void)
519 {
520 	if (!firmware_has_feature(FW_FEATURE_OPAL) ||
521 	    !pvr_version_is(PVR_POWER9) ||
522 	    early_cpu_has_feature(CPU_FTR_TM))
523 		return;
524 
525 	if (opal_reinit_cpus(OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED) != OPAL_SUCCESS)
526 		return;
527 
528 	pr_info("Enabling TM (Transactional Memory) with Suspend Disabled\n");
529 	cur_cpu_spec->cpu_features |= CPU_FTR_TM;
530 	/* Make sure "normal" HTM is off (it should be) */
531 	cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_HTM;
532 	/* Turn on no suspend mode, and HTM no SC */
533 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NO_SUSPEND | \
534 					    PPC_FEATURE2_HTM_NOSC;
535 	tm_suspend_disabled = true;
536 }
537 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
538 
539 /*
540  * Returns the cpu frequency for 'cpu' in Hz. This is used by
541  * /proc/cpuinfo
542  */
pnv_get_proc_freq(unsigned int cpu)543 static unsigned long pnv_get_proc_freq(unsigned int cpu)
544 {
545 	unsigned long ret_freq;
546 
547 	ret_freq = cpufreq_get(cpu) * 1000ul;
548 
549 	/*
550 	 * If the backend cpufreq driver does not exist,
551          * then fallback to old way of reporting the clockrate.
552 	 */
553 	if (!ret_freq)
554 		ret_freq = ppc_proc_freq;
555 	return ret_freq;
556 }
557 
pnv_machine_check_early(struct pt_regs * regs)558 static long pnv_machine_check_early(struct pt_regs *regs)
559 {
560 	long handled = 0;
561 
562 	if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
563 		handled = cur_cpu_spec->machine_check_early(regs);
564 
565 	return handled;
566 }
567 
define_machine(powernv)568 define_machine(powernv) {
569 	.name			= "PowerNV",
570 	.compatible		= "ibm,powernv",
571 	.probe			= pnv_probe,
572 	.setup_arch		= pnv_setup_arch,
573 	.init_IRQ		= pnv_init_IRQ,
574 	.show_cpuinfo		= pnv_show_cpuinfo,
575 	.get_proc_freq          = pnv_get_proc_freq,
576 	.discover_phbs		= pnv_pci_init,
577 	.progress		= pnv_progress,
578 	.machine_shutdown	= pnv_shutdown,
579 	.power_save             = NULL,
580 	.machine_check_early	= pnv_machine_check_early,
581 #ifdef CONFIG_KEXEC_CORE
582 	.kexec_cpu_down		= pnv_kexec_cpu_down,
583 #endif
584 #ifdef CONFIG_MEMORY_HOTPLUG
585 	.memory_block_size	= pnv_memory_block_size,
586 #endif
587 };
588