1 /*
2  * PowerNV setup code.
3  *
4  * Copyright 2011 IBM Corp.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #undef DEBUG
13 
14 #include <linux/cpu.h>
15 #include <linux/errno.h>
16 #include <linux/sched.h>
17 #include <linux/kernel.h>
18 #include <linux/tty.h>
19 #include <linux/reboot.h>
20 #include <linux/init.h>
21 #include <linux/console.h>
22 #include <linux/delay.h>
23 #include <linux/irq.h>
24 #include <linux/seq_file.h>
25 #include <linux/of.h>
26 #include <linux/of_fdt.h>
27 #include <linux/interrupt.h>
28 #include <linux/bug.h>
29 #include <linux/pci.h>
30 #include <linux/cpufreq.h>
31 
32 #include <asm/machdep.h>
33 #include <asm/firmware.h>
34 #include <asm/xics.h>
35 #include <asm/xive.h>
36 #include <asm/opal.h>
37 #include <asm/kexec.h>
38 #include <asm/smp.h>
39 #include <asm/tm.h>
40 #include <asm/setup.h>
41 #include <asm/security_features.h>
42 
43 #include "powernv.h"
44 
45 
46 static bool fw_feature_is(const char *state, const char *name,
47 			  struct device_node *fw_features)
48 {
49 	struct device_node *np;
50 	bool rc = false;
51 
52 	np = of_get_child_by_name(fw_features, name);
53 	if (np) {
54 		rc = of_property_read_bool(np, state);
55 		of_node_put(np);
56 	}
57 
58 	return rc;
59 }
60 
61 static void init_fw_feat_flags(struct device_node *np)
62 {
63 	if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np))
64 		security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
65 
66 	if (fw_feature_is("enabled", "fw-bcctrl-serialized", np))
67 		security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
68 
69 	if (fw_feature_is("enabled", "inst-l1d-flush-ori30,30,0", np))
70 		security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
71 
72 	if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np))
73 		security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
74 
75 	if (fw_feature_is("enabled", "fw-l1d-thread-split", np))
76 		security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
77 
78 	if (fw_feature_is("enabled", "fw-count-cache-disabled", np))
79 		security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
80 
81 	if (fw_feature_is("enabled", "fw-count-cache-flush-bcctr2,0,0", np))
82 		security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST);
83 
84 	if (fw_feature_is("enabled", "needs-count-cache-flush-on-context-switch", np))
85 		security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE);
86 
87 	/*
88 	 * The features below are enabled by default, so we instead look to see
89 	 * if firmware has *disabled* them, and clear them if so.
90 	 */
91 	if (fw_feature_is("disabled", "speculation-policy-favor-security", np))
92 		security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
93 
94 	if (fw_feature_is("disabled", "needs-l1d-flush-msr-pr-0-to-1", np))
95 		security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
96 
97 	if (fw_feature_is("disabled", "needs-l1d-flush-msr-hv-1-to-0", np))
98 		security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
99 
100 	if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np))
101 		security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
102 }
103 
104 static void pnv_setup_rfi_flush(void)
105 {
106 	struct device_node *np, *fw_features;
107 	enum l1d_flush_type type;
108 	bool enable;
109 
110 	/* Default to fallback in case fw-features are not available */
111 	type = L1D_FLUSH_FALLBACK;
112 
113 	np = of_find_node_by_name(NULL, "ibm,opal");
114 	fw_features = of_get_child_by_name(np, "fw-features");
115 	of_node_put(np);
116 
117 	if (fw_features) {
118 		init_fw_feat_flags(fw_features);
119 		of_node_put(fw_features);
120 
121 		if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
122 			type = L1D_FLUSH_MTTRIG;
123 
124 		if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
125 			type = L1D_FLUSH_ORI;
126 	}
127 
128 	enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
129 		 (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR)   || \
130 		  security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
131 
132 	setup_rfi_flush(type, enable);
133 	setup_count_cache_flush();
134 }
135 
136 static void __init pnv_setup_arch(void)
137 {
138 	set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
139 
140 	pnv_setup_rfi_flush();
141 	setup_stf_barrier();
142 
143 	/* Initialize SMP */
144 	pnv_smp_init();
145 
146 	/* Setup PCI */
147 	pnv_pci_init();
148 
149 	/* Setup RTC and NVRAM callbacks */
150 	if (firmware_has_feature(FW_FEATURE_OPAL))
151 		opal_nvram_init();
152 
153 	/* Enable NAP mode */
154 	powersave_nap = 1;
155 
156 	/* XXX PMCS */
157 }
158 
159 static void __init pnv_init(void)
160 {
161 	/*
162 	 * Initialize the LPC bus now so that legacy serial
163 	 * ports can be found on it
164 	 */
165 	opal_lpc_init();
166 
167 #ifdef CONFIG_HVC_OPAL
168 	if (firmware_has_feature(FW_FEATURE_OPAL))
169 		hvc_opal_init_early();
170 	else
171 #endif
172 		add_preferred_console("hvc", 0, NULL);
173 }
174 
175 static void __init pnv_init_IRQ(void)
176 {
177 	/* Try using a XIVE if available, otherwise use a XICS */
178 	if (!xive_native_init())
179 		xics_init();
180 
181 	WARN_ON(!ppc_md.get_irq);
182 }
183 
184 static void pnv_show_cpuinfo(struct seq_file *m)
185 {
186 	struct device_node *root;
187 	const char *model = "";
188 
189 	root = of_find_node_by_path("/");
190 	if (root)
191 		model = of_get_property(root, "model", NULL);
192 	seq_printf(m, "machine\t\t: PowerNV %s\n", model);
193 	if (firmware_has_feature(FW_FEATURE_OPAL))
194 		seq_printf(m, "firmware\t: OPAL\n");
195 	else
196 		seq_printf(m, "firmware\t: BML\n");
197 	of_node_put(root);
198 	if (radix_enabled())
199 		seq_printf(m, "MMU\t\t: Radix\n");
200 	else
201 		seq_printf(m, "MMU\t\t: Hash\n");
202 }
203 
204 static void pnv_prepare_going_down(void)
205 {
206 	/*
207 	 * Disable all notifiers from OPAL, we can't
208 	 * service interrupts anymore anyway
209 	 */
210 	opal_event_shutdown();
211 
212 	/* Print flash update message if one is scheduled. */
213 	opal_flash_update_print_message();
214 
215 	smp_send_stop();
216 
217 	hard_irq_disable();
218 }
219 
220 static void  __noreturn pnv_restart(char *cmd)
221 {
222 	long rc = OPAL_BUSY;
223 
224 	pnv_prepare_going_down();
225 
226 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
227 		rc = opal_cec_reboot();
228 		if (rc == OPAL_BUSY_EVENT)
229 			opal_poll_events(NULL);
230 		else
231 			mdelay(10);
232 	}
233 	for (;;)
234 		opal_poll_events(NULL);
235 }
236 
237 static void __noreturn pnv_power_off(void)
238 {
239 	long rc = OPAL_BUSY;
240 
241 	pnv_prepare_going_down();
242 
243 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
244 		rc = opal_cec_power_down(0);
245 		if (rc == OPAL_BUSY_EVENT)
246 			opal_poll_events(NULL);
247 		else
248 			mdelay(10);
249 	}
250 	for (;;)
251 		opal_poll_events(NULL);
252 }
253 
254 static void __noreturn pnv_halt(void)
255 {
256 	pnv_power_off();
257 }
258 
259 static void pnv_progress(char *s, unsigned short hex)
260 {
261 }
262 
263 static void pnv_shutdown(void)
264 {
265 	/* Let the PCI code clear up IODA tables */
266 	pnv_pci_shutdown();
267 
268 	/*
269 	 * Stop OPAL activity: Unregister all OPAL interrupts so they
270 	 * don't fire up while we kexec and make sure all potentially
271 	 * DMA'ing ops are complete (such as dump retrieval).
272 	 */
273 	opal_shutdown();
274 }
275 
276 #ifdef CONFIG_KEXEC_CORE
277 static void pnv_kexec_wait_secondaries_down(void)
278 {
279 	int my_cpu, i, notified = -1;
280 
281 	my_cpu = get_cpu();
282 
283 	for_each_online_cpu(i) {
284 		uint8_t status;
285 		int64_t rc, timeout = 1000;
286 
287 		if (i == my_cpu)
288 			continue;
289 
290 		for (;;) {
291 			rc = opal_query_cpu_status(get_hard_smp_processor_id(i),
292 						   &status);
293 			if (rc != OPAL_SUCCESS || status != OPAL_THREAD_STARTED)
294 				break;
295 			barrier();
296 			if (i != notified) {
297 				printk(KERN_INFO "kexec: waiting for cpu %d "
298 				       "(physical %d) to enter OPAL\n",
299 				       i, paca_ptrs[i]->hw_cpu_id);
300 				notified = i;
301 			}
302 
303 			/*
304 			 * On crash secondaries might be unreachable or hung,
305 			 * so timeout if we've waited too long
306 			 * */
307 			mdelay(1);
308 			if (timeout-- == 0) {
309 				printk(KERN_ERR "kexec: timed out waiting for "
310 				       "cpu %d (physical %d) to enter OPAL\n",
311 				       i, paca_ptrs[i]->hw_cpu_id);
312 				break;
313 			}
314 		}
315 	}
316 }
317 
318 static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
319 {
320 	u64 reinit_flags;
321 
322 	if (xive_enabled())
323 		xive_teardown_cpu();
324 	else
325 		xics_kexec_teardown_cpu(secondary);
326 
327 	/* On OPAL, we return all CPUs to firmware */
328 	if (!firmware_has_feature(FW_FEATURE_OPAL))
329 		return;
330 
331 	if (secondary) {
332 		/* Return secondary CPUs to firmware on OPAL v3 */
333 		mb();
334 		get_paca()->kexec_state = KEXEC_STATE_REAL_MODE;
335 		mb();
336 
337 		/* Return the CPU to OPAL */
338 		opal_return_cpu();
339 	} else {
340 		/* Primary waits for the secondaries to have reached OPAL */
341 		pnv_kexec_wait_secondaries_down();
342 
343 		/* Switch XIVE back to emulation mode */
344 		if (xive_enabled())
345 			xive_shutdown();
346 
347 		/*
348 		 * We might be running as little-endian - now that interrupts
349 		 * are disabled, reset the HILE bit to big-endian so we don't
350 		 * take interrupts in the wrong endian later
351 		 *
352 		 * We reinit to enable both radix and hash on P9 to ensure
353 		 * the mode used by the next kernel is always supported.
354 		 */
355 		reinit_flags = OPAL_REINIT_CPUS_HILE_BE;
356 		if (cpu_has_feature(CPU_FTR_ARCH_300))
357 			reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX |
358 				OPAL_REINIT_CPUS_MMU_HASH;
359 		opal_reinit_cpus(reinit_flags);
360 	}
361 }
362 #endif /* CONFIG_KEXEC_CORE */
363 
364 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
365 static unsigned long pnv_memory_block_size(void)
366 {
367 	return 256UL * 1024 * 1024;
368 }
369 #endif
370 
371 static void __init pnv_setup_machdep_opal(void)
372 {
373 	ppc_md.get_boot_time = opal_get_boot_time;
374 	ppc_md.restart = pnv_restart;
375 	pm_power_off = pnv_power_off;
376 	ppc_md.halt = pnv_halt;
377 	/* ppc_md.system_reset_exception gets filled in by pnv_smp_init() */
378 	ppc_md.machine_check_exception = opal_machine_check;
379 	ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
380 	ppc_md.hmi_exception_early = opal_hmi_exception_early;
381 	ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
382 }
383 
384 static int __init pnv_probe(void)
385 {
386 	if (!of_machine_is_compatible("ibm,powernv"))
387 		return 0;
388 
389 	if (firmware_has_feature(FW_FEATURE_OPAL))
390 		pnv_setup_machdep_opal();
391 
392 	pr_debug("PowerNV detected !\n");
393 
394 	pnv_init();
395 
396 	return 1;
397 }
398 
399 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
400 void __init pnv_tm_init(void)
401 {
402 	if (!firmware_has_feature(FW_FEATURE_OPAL) ||
403 	    !pvr_version_is(PVR_POWER9) ||
404 	    early_cpu_has_feature(CPU_FTR_TM))
405 		return;
406 
407 	if (opal_reinit_cpus(OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED) != OPAL_SUCCESS)
408 		return;
409 
410 	pr_info("Enabling TM (Transactional Memory) with Suspend Disabled\n");
411 	cur_cpu_spec->cpu_features |= CPU_FTR_TM;
412 	/* Make sure "normal" HTM is off (it should be) */
413 	cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_HTM;
414 	/* Turn on no suspend mode, and HTM no SC */
415 	cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NO_SUSPEND | \
416 					    PPC_FEATURE2_HTM_NOSC;
417 	tm_suspend_disabled = true;
418 }
419 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
420 
421 /*
422  * Returns the cpu frequency for 'cpu' in Hz. This is used by
423  * /proc/cpuinfo
424  */
425 static unsigned long pnv_get_proc_freq(unsigned int cpu)
426 {
427 	unsigned long ret_freq;
428 
429 	ret_freq = cpufreq_get(cpu) * 1000ul;
430 
431 	/*
432 	 * If the backend cpufreq driver does not exist,
433          * then fallback to old way of reporting the clockrate.
434 	 */
435 	if (!ret_freq)
436 		ret_freq = ppc_proc_freq;
437 	return ret_freq;
438 }
439 
440 define_machine(powernv) {
441 	.name			= "PowerNV",
442 	.probe			= pnv_probe,
443 	.setup_arch		= pnv_setup_arch,
444 	.init_IRQ		= pnv_init_IRQ,
445 	.show_cpuinfo		= pnv_show_cpuinfo,
446 	.get_proc_freq          = pnv_get_proc_freq,
447 	.progress		= pnv_progress,
448 	.machine_shutdown	= pnv_shutdown,
449 	.power_save             = NULL,
450 	.calibrate_decr		= generic_calibrate_decr,
451 #ifdef CONFIG_KEXEC_CORE
452 	.kexec_cpu_down		= pnv_kexec_cpu_down,
453 #endif
454 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
455 	.memory_block_size	= pnv_memory_block_size,
456 #endif
457 };
458