1 // SPDX-License-Identifier: GPL-2.0-or-later
5 * Copyright 2011 IBM Corp.
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>
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>
29 #include <asm/machdep.h>
30 #include <asm/firmware.h>
34 #include <asm/kexec.h>
37 #include <asm/setup.h>
38 #include <asm/security_features.h>
43 static bool fw_feature_is(const char *state, const char *name,
44 struct device_node *fw_features)
46 struct device_node *np;
49 np = of_get_child_by_name(fw_features, name);
51 rc = of_property_read_bool(np, state);
58 static void init_fw_feat_flags(struct device_node *np)
60 if (fw_feature_is("enabled", "inst-spec-barrier-ori31,31,0", np))
61 security_ftr_set(SEC_FTR_SPEC_BAR_ORI31);
63 if (fw_feature_is("enabled", "fw-bcctrl-serialized", np))
64 security_ftr_set(SEC_FTR_BCCTRL_SERIALISED);
66 if (fw_feature_is("enabled", "inst-l1d-flush-ori30,30,0", np))
67 security_ftr_set(SEC_FTR_L1D_FLUSH_ORI30);
69 if (fw_feature_is("enabled", "inst-l1d-flush-trig2", np))
70 security_ftr_set(SEC_FTR_L1D_FLUSH_TRIG2);
72 if (fw_feature_is("enabled", "fw-l1d-thread-split", np))
73 security_ftr_set(SEC_FTR_L1D_THREAD_PRIV);
75 if (fw_feature_is("enabled", "fw-count-cache-disabled", np))
76 security_ftr_set(SEC_FTR_COUNT_CACHE_DISABLED);
78 if (fw_feature_is("enabled", "fw-count-cache-flush-bcctr2,0,0", np))
79 security_ftr_set(SEC_FTR_BCCTR_FLUSH_ASSIST);
81 if (fw_feature_is("enabled", "needs-count-cache-flush-on-context-switch", np))
82 security_ftr_set(SEC_FTR_FLUSH_COUNT_CACHE);
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.
88 if (fw_feature_is("disabled", "speculation-policy-favor-security", np))
89 security_ftr_clear(SEC_FTR_FAVOUR_SECURITY);
91 if (fw_feature_is("disabled", "needs-l1d-flush-msr-pr-0-to-1", np))
92 security_ftr_clear(SEC_FTR_L1D_FLUSH_PR);
94 if (fw_feature_is("disabled", "needs-l1d-flush-msr-hv-1-to-0", np))
95 security_ftr_clear(SEC_FTR_L1D_FLUSH_HV);
97 if (fw_feature_is("disabled", "needs-spec-barrier-for-bound-checks", np))
98 security_ftr_clear(SEC_FTR_BNDS_CHK_SPEC_BAR);
101 static void pnv_setup_security_mitigations(void)
103 struct device_node *np, *fw_features;
104 enum l1d_flush_type type;
107 /* Default to fallback in case fw-features are not available */
108 type = L1D_FLUSH_FALLBACK;
110 np = of_find_node_by_name(NULL, "ibm,opal");
111 fw_features = of_get_child_by_name(np, "fw-features");
115 init_fw_feat_flags(fw_features);
116 of_node_put(fw_features);
118 if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_TRIG2))
119 type = L1D_FLUSH_MTTRIG;
121 if (security_ftr_enabled(SEC_FTR_L1D_FLUSH_ORI30))
122 type = L1D_FLUSH_ORI;
126 * If we are non-Power9 bare metal, we don't need to flush on kernel
127 * entry or after user access: they fix a P9 specific vulnerability.
129 if (!pvr_version_is(PVR_POWER9)) {
130 security_ftr_clear(SEC_FTR_L1D_FLUSH_ENTRY);
131 security_ftr_clear(SEC_FTR_L1D_FLUSH_UACCESS);
134 enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) && \
135 (security_ftr_enabled(SEC_FTR_L1D_FLUSH_PR) || \
136 security_ftr_enabled(SEC_FTR_L1D_FLUSH_HV));
138 setup_rfi_flush(type, enable);
139 setup_count_cache_flush();
141 enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
142 security_ftr_enabled(SEC_FTR_L1D_FLUSH_ENTRY);
143 setup_entry_flush(enable);
145 enable = security_ftr_enabled(SEC_FTR_FAVOUR_SECURITY) &&
146 security_ftr_enabled(SEC_FTR_L1D_FLUSH_UACCESS);
147 setup_uaccess_flush(enable);
152 static void __init pnv_check_guarded_cores(void)
154 struct device_node *dn;
157 for_each_node_by_type(dn, "cpu") {
158 if (of_property_match_string(dn, "status", "bad") >= 0)
163 printk(" _ _______________\n");
164 pr_cont(" | | / \\\n");
165 pr_cont(" | | | WARNING! |\n");
166 pr_cont(" | | | |\n");
167 pr_cont(" | | | It looks like |\n");
168 pr_cont(" |_| | you have %*d |\n", 3, bad_count);
169 pr_cont(" _ | guarded cores |\n");
170 pr_cont(" (_) \\_______________/\n");
174 static void __init pnv_setup_arch(void)
176 set_arch_panic_timeout(10, ARCH_PANIC_TIMEOUT);
178 pnv_setup_security_mitigations();
183 /* Setup RTC and NVRAM callbacks */
184 if (firmware_has_feature(FW_FEATURE_OPAL))
187 /* Enable NAP mode */
190 pnv_check_guarded_cores();
195 static void __init pnv_init(void)
198 * Initialize the LPC bus now so that legacy serial
199 * ports can be found on it
203 #ifdef CONFIG_HVC_OPAL
204 if (firmware_has_feature(FW_FEATURE_OPAL))
205 hvc_opal_init_early();
208 add_preferred_console("hvc", 0, NULL);
210 if (!radix_enabled()) {
211 size_t size = sizeof(struct slb_entry) * mmu_slb_size;
214 /* Allocate per cpu area to save old slb contents during MCE */
215 for_each_possible_cpu(i) {
216 paca_ptrs[i]->mce_faulty_slbs =
217 memblock_alloc_node(size,
218 __alignof__(struct slb_entry),
224 static void __init pnv_init_IRQ(void)
226 /* Try using a XIVE if available, otherwise use a XICS */
227 if (!xive_native_init())
230 WARN_ON(!ppc_md.get_irq);
233 static void pnv_show_cpuinfo(struct seq_file *m)
235 struct device_node *root;
236 const char *model = "";
238 root = of_find_node_by_path("/");
240 model = of_get_property(root, "model", NULL);
241 seq_printf(m, "machine\t\t: PowerNV %s\n", model);
242 if (firmware_has_feature(FW_FEATURE_OPAL))
243 seq_printf(m, "firmware\t: OPAL\n");
245 seq_printf(m, "firmware\t: BML\n");
248 seq_printf(m, "MMU\t\t: Radix\n");
250 seq_printf(m, "MMU\t\t: Hash\n");
253 static void pnv_prepare_going_down(void)
256 * Disable all notifiers from OPAL, we can't
257 * service interrupts anymore anyway
259 opal_event_shutdown();
261 /* Print flash update message if one is scheduled. */
262 opal_flash_update_print_message();
269 static void __noreturn pnv_restart(char *cmd)
273 pnv_prepare_going_down();
276 if (!cmd || !strlen(cmd))
277 rc = opal_cec_reboot();
278 else if (strcmp(cmd, "full") == 0)
279 rc = opal_cec_reboot2(OPAL_REBOOT_FULL_IPL, NULL);
280 else if (strcmp(cmd, "mpipl") == 0)
281 rc = opal_cec_reboot2(OPAL_REBOOT_MPIPL, NULL);
282 else if (strcmp(cmd, "error") == 0)
283 rc = opal_cec_reboot2(OPAL_REBOOT_PLATFORM_ERROR, NULL);
284 else if (strcmp(cmd, "fast") == 0)
285 rc = opal_cec_reboot2(OPAL_REBOOT_FAST, NULL);
287 rc = OPAL_UNSUPPORTED;
289 if (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
290 /* Opal is busy wait for some time and retry */
291 opal_poll_events(NULL);
294 } else if (cmd && rc) {
295 /* Unknown error while issuing reboot */
296 if (rc == OPAL_UNSUPPORTED)
297 pr_err("Unsupported '%s' reboot.\n", cmd);
299 pr_err("Unable to issue '%s' reboot. Err=%ld\n",
301 pr_info("Forcing a cec-reboot\n");
305 } else if (rc != OPAL_SUCCESS) {
306 /* Unknown error while issuing cec-reboot */
307 pr_err("Unable to reboot. Err=%ld\n", rc);
310 } while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT);
313 opal_poll_events(NULL);
316 static void __noreturn pnv_power_off(void)
320 pnv_prepare_going_down();
322 while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
323 rc = opal_cec_power_down(0);
324 if (rc == OPAL_BUSY_EVENT)
325 opal_poll_events(NULL);
330 opal_poll_events(NULL);
333 static void __noreturn pnv_halt(void)
338 static void pnv_progress(char *s, unsigned short hex)
342 static void pnv_shutdown(void)
344 /* Let the PCI code clear up IODA tables */
348 * Stop OPAL activity: Unregister all OPAL interrupts so they
349 * don't fire up while we kexec and make sure all potentially
350 * DMA'ing ops are complete (such as dump retrieval).
355 #ifdef CONFIG_KEXEC_CORE
356 static void pnv_kexec_wait_secondaries_down(void)
358 int my_cpu, i, notified = -1;
362 for_each_online_cpu(i) {
364 int64_t rc, timeout = 1000;
370 rc = opal_query_cpu_status(get_hard_smp_processor_id(i),
372 if (rc != OPAL_SUCCESS || status != OPAL_THREAD_STARTED)
376 printk(KERN_INFO "kexec: waiting for cpu %d "
377 "(physical %d) to enter OPAL\n",
378 i, paca_ptrs[i]->hw_cpu_id);
383 * On crash secondaries might be unreachable or hung,
384 * so timeout if we've waited too long
387 if (timeout-- == 0) {
388 printk(KERN_ERR "kexec: timed out waiting for "
389 "cpu %d (physical %d) to enter OPAL\n",
390 i, paca_ptrs[i]->hw_cpu_id);
397 static void pnv_kexec_cpu_down(int crash_shutdown, int secondary)
404 xics_kexec_teardown_cpu(secondary);
406 /* On OPAL, we return all CPUs to firmware */
407 if (!firmware_has_feature(FW_FEATURE_OPAL))
411 /* Return secondary CPUs to firmware on OPAL v3 */
413 get_paca()->kexec_state = KEXEC_STATE_REAL_MODE;
416 /* Return the CPU to OPAL */
419 /* Primary waits for the secondaries to have reached OPAL */
420 pnv_kexec_wait_secondaries_down();
422 /* Switch XIVE back to emulation mode */
427 * We might be running as little-endian - now that interrupts
428 * are disabled, reset the HILE bit to big-endian so we don't
429 * take interrupts in the wrong endian later
431 * We reinit to enable both radix and hash on P9 to ensure
432 * the mode used by the next kernel is always supported.
434 reinit_flags = OPAL_REINIT_CPUS_HILE_BE;
435 if (cpu_has_feature(CPU_FTR_ARCH_300))
436 reinit_flags |= OPAL_REINIT_CPUS_MMU_RADIX |
437 OPAL_REINIT_CPUS_MMU_HASH;
438 opal_reinit_cpus(reinit_flags);
441 #endif /* CONFIG_KEXEC_CORE */
443 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
444 static unsigned long pnv_memory_block_size(void)
447 * We map the kernel linear region with 1GB large pages on radix. For
448 * memory hot unplug to work our memory block size must be at least
452 return radix_mem_block_size;
454 return 256UL * 1024 * 1024;
458 static void __init pnv_setup_machdep_opal(void)
460 ppc_md.get_boot_time = opal_get_boot_time;
461 ppc_md.restart = pnv_restart;
462 pm_power_off = pnv_power_off;
463 ppc_md.halt = pnv_halt;
464 /* ppc_md.system_reset_exception gets filled in by pnv_smp_init() */
465 ppc_md.machine_check_exception = opal_machine_check;
466 ppc_md.mce_check_early_recovery = opal_mce_check_early_recovery;
467 if (opal_check_token(OPAL_HANDLE_HMI2))
468 ppc_md.hmi_exception_early = opal_hmi_exception_early2;
470 ppc_md.hmi_exception_early = opal_hmi_exception_early;
471 ppc_md.handle_hmi_exception = opal_handle_hmi_exception;
474 static int __init pnv_probe(void)
476 if (!of_machine_is_compatible("ibm,powernv"))
479 if (firmware_has_feature(FW_FEATURE_OPAL))
480 pnv_setup_machdep_opal();
482 pr_debug("PowerNV detected !\n");
489 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
490 void __init pnv_tm_init(void)
492 if (!firmware_has_feature(FW_FEATURE_OPAL) ||
493 !pvr_version_is(PVR_POWER9) ||
494 early_cpu_has_feature(CPU_FTR_TM))
497 if (opal_reinit_cpus(OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED) != OPAL_SUCCESS)
500 pr_info("Enabling TM (Transactional Memory) with Suspend Disabled\n");
501 cur_cpu_spec->cpu_features |= CPU_FTR_TM;
502 /* Make sure "normal" HTM is off (it should be) */
503 cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_HTM;
504 /* Turn on no suspend mode, and HTM no SC */
505 cur_cpu_spec->cpu_user_features2 |= PPC_FEATURE2_HTM_NO_SUSPEND | \
506 PPC_FEATURE2_HTM_NOSC;
507 tm_suspend_disabled = true;
509 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
512 * Returns the cpu frequency for 'cpu' in Hz. This is used by
515 static unsigned long pnv_get_proc_freq(unsigned int cpu)
517 unsigned long ret_freq;
519 ret_freq = cpufreq_get(cpu) * 1000ul;
522 * If the backend cpufreq driver does not exist,
523 * then fallback to old way of reporting the clockrate.
526 ret_freq = ppc_proc_freq;
530 static long pnv_machine_check_early(struct pt_regs *regs)
534 if (cur_cpu_spec && cur_cpu_spec->machine_check_early)
535 handled = cur_cpu_spec->machine_check_early(regs);
540 define_machine(powernv) {
543 .setup_arch = pnv_setup_arch,
544 .init_IRQ = pnv_init_IRQ,
545 .show_cpuinfo = pnv_show_cpuinfo,
546 .get_proc_freq = pnv_get_proc_freq,
547 .discover_phbs = pnv_pci_init,
548 .progress = pnv_progress,
549 .machine_shutdown = pnv_shutdown,
551 .calibrate_decr = generic_calibrate_decr,
552 .machine_check_early = pnv_machine_check_early,
553 #ifdef CONFIG_KEXEC_CORE
554 .kexec_cpu_down = pnv_kexec_cpu_down,
556 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE
557 .memory_block_size = pnv_memory_block_size,