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_file.h>
21 #include <linux/of.h>
22 #include <linux/of_fdt.h>
23 #include <linux/interrupt.h>
24 #include <linux/bug.h>
25 #include <linux/pci.h>
26 #include <linux/cpufreq.h>
27 #include <linux/memblock.h>
28 
29 #include <asm/machdep.h>
30 #include <asm/firmware.h>
31 #include <asm/xics.h>
32 #include <asm/xive.h>
33 #include <asm/opal.h>
34 #include <asm/kexec.h>
35 #include <asm/smp.h>
36 #include <asm/tm.h>
37 #include <asm/setup.h>
38 #include <asm/security_features.h>
39 
40 #include "powernv.h"
41 
42 
43 static bool fw_feature_is(const char *state, const char *name,
44 			  struct device_node *fw_features)
45 {
46 	struct device_node *np;
47 	bool rc = false;
48 
49 	np = of_get_child_by_name(fw_features, name);
50 	if (np) {
51 		rc = of_property_read_bool(np, state);
52 		of_node_put(np);
53 	}
54 
55 	return rc;
56 }
57 
58 static void init_fw_feat_flags(struct device_node *np)
59 {
60 	if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np))
61 		security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
62 
63 	if (fw_feature_is("enabled", "fw-bcctrl-serialized", np))
64 		security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
65 
66 	if (fw_feature_is("enabled", "inst-l1d-flush-ori30,30,0", np))
67 		security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
68 
69 	if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np))
70 		security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
71 
72 	if (fw_feature_is("enabled", "fw-l1d-thread-split", np))
73 		security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
74 
75 	if (fw_feature_is("enabled", "fw-count-cache-disabled", np))
76 		security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
77 
78 	if (fw_feature_is("enabled", "fw-count-cache-flush-bcctr2,0,0", np))
79 		security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST);
80 
81 	if (fw_feature_is("enabled", "needs-count-cache-flush-on-context-switch", np))
82 		security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE);
83 
84 	/*
85 	 * The features below are enabled by default, so we instead look to see
86 	 * if firmware has *disabled* them, and clear them if so.
87 	 */
88 	if (fw_feature_is("disabled", "speculation-policy-favor-security", np))
89 		security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
90 
91 	if (fw_feature_is("disabled", "needs-l1d-flush-msr-pr-0-to-1", np))
92 		security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
93 
94 	if (fw_feature_is("disabled", "needs-l1d-flush-msr-hv-1-to-0", np))
95 		security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
96 
97 	if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np))
98 		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
99 }
100 
101 static void pnv_setup_rfi_flush(void)
102 {
103 	struct device_node *np, *fw_features;
104 	enum l1d_flush_type type;
105 	bool enable;
106 
107 	/* Default to fallback in case fw-features are not available */
108 	type = L1D_FLUSH_FALLBACK;
109 
110 	np = of_find_node_by_name(NULL, "ibm,opal");
111 	fw_features = of_get_child_by_name(np, "fw-features");
112 	of_node_put(np);
113 
114 	if (fw_features) {
115 		init_fw_feat_flags(fw_features);
116 		of_node_put(fw_features);
117 
118 		if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
119 			type = L1D_FLUSH_MTTRIG;
120 
121 		if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
122 			type = L1D_FLUSH_ORI;
123 	}
124 
125 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
126 		 (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
127 		  security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
128 
129 	setup_rfi_flush(type, enable);
130 	setup_count_cache_flush();
131 }
132 
133 static void __init pnv_setup_arch(void)
134 {
135 	set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
136 
137 	pnv_setup_rfi_flush();
138 	setup_stf_barrier();
139 
140 	/* Initialize SMP */
141 	pnv_smp_init();
142 
143 	/* Setup PCI */
144 	pnv_pci_init();
145 
146 	/* Setup RTC and NVRAM callbacks */
147 	if (firmware_has_feature(FW_FEATURE_OPAL))
148 		opal_nvram_init();
149 
150 	/* Enable NAP mode */
151 	powersave_nap = 1;
152 
153 	/* XXX PMCS */
154 }
155 
156 static void __init pnv_init(void)
157 {
158 	/*
159 	 * Initialize the LPC bus now so that legacy serial
160 	 * ports can be found on it
161 	 */
162 	opal_lpc_init();
163 
164 #ifdef CONFIG_HVC_OPAL
165 	if (firmware_has_feature(FW_FEATURE_OPAL))
166 		hvc_opal_init_early();
167 	else
168 #endif
169 		add_preferred_console("hvc", 0, NULL);
170 
171 	if (!radix_enabled()) {
172 		int i;
173 
174 		/* Allocate per cpu area to save old slb contents during MCE */
175 		for_each_possible_cpu(i)
176 			paca_ptrs[i]->mce_faulty_slbs = memblock_alloc_node(mmu_slb_size, __alignof__(*paca_ptrs[i]->mce_faulty_slbs), cpu_to_node(i));
177 	}
178 }
179 
180 static void __init pnv_init_IRQ(void)
181 {
182 	/* Try using a XIVE if available, otherwise use a XICS */
183 	if (!xive_native_init())
184 		xics_init();
185 
186 	WARN_ON(!ppc_md.get_irq);
187 }
188 
189 static void pnv_show_cpuinfo(struct seq_file *m)
190 {
191 	struct device_node *root;
192 	const char *model = "";
193 
194 	root = of_find_node_by_path("/");
195 	if (root)
196 		model = of_get_property(root, "model", NULL);
197 	seq_printf(m, "machine\t\t: PowerNV %s\n", model);
198 	if (firmware_has_feature(FW_FEATURE_OPAL))
199 		seq_printf(m, "firmware\t: OPAL\n");
200 	else
201 		seq_printf(m, "firmware\t: BML\n");
202 	of_node_put(root);
203 	if (radix_enabled())
204 		seq_printf(m, "MMU\t\t: Radix\n");
205 	else
206 		seq_printf(m, "MMU\t\t: Hash\n");
207 }
208 
209 static void pnv_prepare_going_down(void)
210 {
211 	/*
212 	 * Disable all notifiers from OPAL, we can't
213 	 * service interrupts anymore anyway
214 	 */
215 	opal_event_shutdown();
216 
217 	/* Print flash update message if one is scheduled. */
218 	opal_flash_update_print_message();
219 
220 	smp_send_stop();
221 
222 	hard_irq_disable();
223 }
224 
225 static void  __noreturn pnv_restart(char *cmd)
226 {
227 	long rc;
228 
229 	pnv_prepare_going_down();
230 
231 	do {
232 		if (!cmd)
233 			rc = opal_cec_reboot();
234 		else if (strcmp(cmd, "full") == 0)
235 			rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
236 		else
237 			rc = OPAL_UNSUPPORTED;
238 
239 		if (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
240 			/* Opal is busy wait for some time and retry */
241 			opal_poll_events(NULL);
242 			mdelay(10);
243 
244 		} else	if (cmd && rc) {
245 			/* Unknown error while issuing reboot */
246 			if (rc == OPAL_UNSUPPORTED)
247 				pr_err("Unsupported '%s' reboot.\n", cmd);
248 			else
249 				pr_err("Unable to issue '%s' reboot. Err=%ld\n",
250 				       cmd, rc);
251 			pr_info("Forcing a cec-reboot\n");
252 			cmd = NULL;
253 			rc = OPAL_BUSY;
254 
255 		} else if (rc != OPAL_SUCCESS) {
256 			/* Unknown error while issuing cec-reboot */
257 			pr_err("Unable to reboot. Err=%ld\n", rc);
258 		}
259 
260 	} while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT);
261 
262 	for (;;)
263 		opal_poll_events(NULL);
264 }
265 
266 static void __noreturn pnv_power_off(void)
267 {
268 	long rc = OPAL_BUSY;
269 
270 	pnv_prepare_going_down();
271 
272 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
273 		rc = opal_cec_power_down(0);
274 		if (rc == OPAL_BUSY_EVENT)
275 			opal_poll_events(NULL);
276 		else
277 			mdelay(10);
278 	}
279 	for (;;)
280 		opal_poll_events(NULL);
281 }
282 
283 static void __noreturn pnv_halt(void)
284 {
285 	pnv_power_off();
286 }
287 
288 static void pnv_progress(char *s, unsigned short hex)
289 {
290 }
291 
292 static void pnv_shutdown(void)
293 {
294 	/* Let the PCI code clear up IODA tables */
295 	pnv_pci_shutdown();
296 
297 	/*
298 	 * Stop OPAL activity: Unregister all OPAL interrupts so they
299 	 * don't fire up while we kexec and make sure all potentially
300 	 * DMA'ing ops are complete (such as dump retrieval).
301 	 */
302 	opal_shutdown();
303 }
304 
305 #ifdef CONFIG_KEXEC_CORE
306 static void pnv_kexec_wait_secondaries_down(void)
307 {
308 	int my_cpu, i, notified = -1;
309 
310 	my_cpu = get_cpu();
311 
312 	for_each_online_cpu(i) {
313 		uint8_t status;
314 		int64_t rc, timeout = 1000;
315 
316 		if (i == my_cpu)
317 			continue;
318 
319 		for (;;) {
320 			rc = opal_query_cpu_status(get_hard_smp_processor_id(i),
321 						   &status);
322 			if (rc != OPAL_SUCCESS || status != OPAL_THREAD_STARTED)
323 				break;
324 			barrier();
325 			if (i != notified) {
326 				printk(KERN_INFO "kexec: waiting for cpu %d "
327 				       "(physical %d) to enter OPAL\n",
328 				       i, paca_ptrs[i]->hw_cpu_id);
329 				notified = i;
330 			}
331 
332 			/*
333 			 * On crash secondaries might be unreachable or hung,
334 			 * so timeout if we've waited too long
335 			 * */
336 			mdelay(1);
337 			if (timeout-- == 0) {
338 				printk(KERN_ERR "kexec: timed out waiting for "
339 				       "cpu %d (physical %d) to enter OPAL\n",
340 				       i, paca_ptrs[i]->hw_cpu_id);
341 				break;
342 			}
343 		}
344 	}
345 }
346 
347 static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
348 {
349 	u64 reinit_flags;
350 
351 	if (xive_enabled())
352 		xive_teardown_cpu();
353 	else
354 		xics_kexec_teardown_cpu(secondary);
355 
356 	/* On OPAL, we return all CPUs to firmware */
357 	if (!firmware_has_feature(FW_FEATURE_OPAL))
358 		return;
359 
360 	if (secondary) {
361 		/* Return secondary CPUs to firmware on OPAL v3 */
362 		mb();
363 		get_paca()->kexec_state = KEXEC_STATE_REAL_MODE;
364 		mb();
365 
366 		/* Return the CPU to OPAL */
367 		opal_return_cpu();
368 	} else {
369 		/* Primary waits for the secondaries to have reached OPAL */
370 		pnv_kexec_wait_secondaries_down();
371 
372 		/* Switch XIVE back to emulation mode */
373 		if (xive_enabled())
374 			xive_shutdown();
375 
376 		/*
377 		 * We might be running as little-endian - now that interrupts
378 		 * are disabled, reset the HILE bit to big-endian so we don't
379 		 * take interrupts in the wrong endian later
380 		 *
381 		 * We reinit to enable both radix and hash on P9 to ensure
382 		 * the mode used by the next kernel is always supported.
383 		 */
384 		reinit_flags = OPAL_REINIT_CPUS_HILE_BE;
385 		if (cpu_has_feature(CPU_FTR_ARCH_300))
386 			reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX |
387 				OPAL_REINIT_CPUS_MMU_HASH;
388 		opal_reinit_cpus(reinit_flags);
389 	}
390 }
391 #endif /* CONFIG_KEXEC_CORE */
392 
393 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
394 static unsigned long pnv_memory_block_size(void)
395 {
396 	return 256UL * 1024 * 1024;
397 }
398 #endif
399 
400 static void __init pnv_setup_machdep_opal(void)
401 {
402 	ppc_md.get_boot_time = opal_get_boot_time;
403 	ppc_md.restart = pnv_restart;
404 	pm_power_off = pnv_power_off;
405 	ppc_md.halt = pnv_halt;
406 	/* ppc_md.system_reset_exception gets filled in by pnv_smp_init() */
407 	ppc_md.machine_check_exception = opal_machine_check;
408 	ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
409 	if (opal_check_token(OPAL_HANDLE_HMI2))
410 		ppc_md.hmi_exception_early = opal_hmi_exception_early2;
411 	else
412 		ppc_md.hmi_exception_early = opal_hmi_exception_early;
413 	ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
414 }
415 
416 static int __init pnv_probe(void)
417 {
418 	if (!of_machine_is_compatible("ibm,powernv"))
419 		return 0;
420 
421 	if (firmware_has_feature(FW_FEATURE_OPAL))
422 		pnv_setup_machdep_opal();
423 
424 	pr_debug("PowerNV detected !\n");
425 
426 	pnv_init();
427 
428 	return 1;
429 }
430 
431 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
432 void __init pnv_tm_init(void)
433 {
434 	if (!firmware_has_feature(FW_FEATURE_OPAL) ||
435 	    !pvr_version_is(PVR_POWER9) ||
436 	    early_cpu_has_feature(CPU_FTR_TM))
437 		return;
438 
439 	if (opal_reinit_cpus(OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED) != OPAL_SUCCESS)
440 		return;
441 
442 	pr_info("Enabling TM (Transactional Memory) with Suspend Disabled\n");
443 	cur_cpu_spec->cpu_features |= CPU_FTR_TM;
444 	/* Make sure "normal" HTM is off (it should be) */
445 	cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_HTM;
446 	/* Turn on no suspend mode, and HTM no SC */
447 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NO_SUSPEND | \
448 					    PPC_FEATURE2_HTM_NOSC;
449 	tm_suspend_disabled = true;
450 }
451 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
452 
453 /*
454  * Returns the cpu frequency for 'cpu' in Hz. This is used by
455  * /proc/cpuinfo
456  */
457 static unsigned long pnv_get_proc_freq(unsigned int cpu)
458 {
459 	unsigned long ret_freq;
460 
461 	ret_freq = cpufreq_get(cpu) * 1000ul;
462 
463 	/*
464 	 * If the backend cpufreq driver does not exist,
465          * then fallback to old way of reporting the clockrate.
466 	 */
467 	if (!ret_freq)
468 		ret_freq = ppc_proc_freq;
469 	return ret_freq;
470 }
471 
472 static long pnv_machine_check_early(struct pt_regs *regs)
473 {
474 	long handled = 0;
475 
476 	if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
477 		handled = cur_cpu_spec->machine_check_early(regs);
478 
479 	return handled;
480 }
481 
482 define_machine(powernv) {
483 	.name			= "PowerNV",
484 	.probe			= pnv_probe,
485 	.setup_arch		= pnv_setup_arch,
486 	.init_IRQ		= pnv_init_IRQ,
487 	.show_cpuinfo		= pnv_show_cpuinfo,
488 	.get_proc_freq          = pnv_get_proc_freq,
489 	.progress		= pnv_progress,
490 	.machine_shutdown	= pnv_shutdown,
491 	.power_save             = NULL,
492 	.calibrate_decr		= generic_calibrate_decr,
493 	.machine_check_early	= pnv_machine_check_early,
494 #ifdef CONFIG_KEXEC_CORE
495 	.kexec_cpu_down		= pnv_kexec_cpu_down,
496 #endif
497 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
498 	.memory_block_size	= pnv_memory_block_size,
499 #endif
500 };
501