1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * Common boot and setup code for both 32-bit and 64-bit.
4 * Extracted from arch/powerpc/kernel/setup_64.c.
6 * Copyright (C) 2001 PPC64 Team, IBM Corp
11 #include <linux/export.h>
12 #include <linux/panic_notifier.h>
13 #include <linux/string.h>
14 #include <linux/sched.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/reboot.h>
18 #include <linux/delay.h>
19 #include <linux/initrd.h>
20 #include <linux/platform_device.h>
21 #include <linux/seq_file.h>
22 #include <linux/ioport.h>
23 #include <linux/console.h>
24 #include <linux/screen_info.h>
25 #include <linux/root_dev.h>
26 #include <linux/notifier.h>
27 #include <linux/cpu.h>
28 #include <linux/unistd.h>
29 #include <linux/serial.h>
30 #include <linux/serial_8250.h>
31 #include <linux/percpu.h>
32 #include <linux/memblock.h>
33 #include <linux/of_platform.h>
34 #include <linux/hugetlb.h>
35 #include <linux/pgtable.h>
36 #include <asm/debugfs.h>
40 #include <asm/processor.h>
41 #include <asm/vdso_datapage.h>
44 #include <asm/machdep.h>
46 #include <asm/cputable.h>
47 #include <asm/sections.h>
48 #include <asm/firmware.h>
49 #include <asm/btext.h>
50 #include <asm/nvram.h>
51 #include <asm/setup.h>
53 #include <asm/iommu.h>
54 #include <asm/serial.h>
55 #include <asm/cache.h>
59 #include <asm/cputhreads.h>
60 #include <mm/mmu_decl.h>
61 #include <asm/fadump.h>
63 #include <asm/hugetlb.h>
64 #include <asm/livepatch.h>
65 #include <asm/mmu_context.h>
66 #include <asm/cpu_has_feature.h>
67 #include <asm/kasan.h>
73 #define DBG(fmt...) udbg_printf(fmt)
78 /* The main machine-dep calls structure
80 struct machdep_calls ppc_md;
81 EXPORT_SYMBOL(ppc_md);
82 struct machdep_calls *machine_id;
83 EXPORT_SYMBOL(machine_id);
86 EXPORT_SYMBOL_GPL(boot_cpuid);
89 * These are used in binfmt_elf.c to put aux entries on the stack
90 * for each elf executable being started.
96 * This still seems to be needed... -- paulus
98 struct screen_info screen_info = {
101 .orig_video_cols = 80,
102 .orig_video_lines = 25,
103 .orig_video_isVGA = 1,
104 .orig_video_points = 16
106 #if defined(CONFIG_FB_VGA16_MODULE)
107 EXPORT_SYMBOL(screen_info);
110 /* Variables required to store legacy IO irq routing */
111 int of_i8042_kbd_irq;
112 EXPORT_SYMBOL_GPL(of_i8042_kbd_irq);
113 int of_i8042_aux_irq;
114 EXPORT_SYMBOL_GPL(of_i8042_aux_irq);
116 #ifdef __DO_IRQ_CANON
117 /* XXX should go elsewhere eventually */
118 int ppc_do_canonicalize_irqs;
119 EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
122 #ifdef CONFIG_CRASH_CORE
123 /* This keeps a track of which one is the crashing cpu. */
124 int crashing_cpu = -1;
127 /* also used by kexec */
128 void machine_shutdown(void)
131 * if fadump is active, cleanup the fadump registration before we
136 if (ppc_md.machine_shutdown)
137 ppc_md.machine_shutdown();
140 static void machine_hang(void)
142 pr_emerg("System Halted, OK to turn off power\n");
148 void machine_restart(char *cmd)
156 do_kernel_restart(cmd);
162 void machine_power_off(void)
171 /* Used by the G5 thermal driver */
172 EXPORT_SYMBOL_GPL(machine_power_off);
174 void (*pm_power_off)(void);
175 EXPORT_SYMBOL_GPL(pm_power_off);
177 void machine_halt(void)
188 DEFINE_PER_CPU(unsigned int, cpu_pvr);
191 static void show_cpuinfo_summary(struct seq_file *m)
193 struct device_node *root;
194 const char *model = NULL;
195 unsigned long bogosum = 0;
198 if (IS_ENABLED(CONFIG_SMP) && IS_ENABLED(CONFIG_PPC32)) {
199 for_each_online_cpu(i)
200 bogosum += loops_per_jiffy;
201 seq_printf(m, "total bogomips\t: %lu.%02lu\n",
202 bogosum / (500000 / HZ), bogosum / (5000 / HZ) % 100);
204 seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq);
206 seq_printf(m, "platform\t: %s\n", ppc_md.name);
207 root = of_find_node_by_path("/");
209 model = of_get_property(root, "model", NULL);
211 seq_printf(m, "model\t\t: %s\n", model);
214 if (ppc_md.show_cpuinfo != NULL)
215 ppc_md.show_cpuinfo(m);
217 /* Display the amount of memory */
218 if (IS_ENABLED(CONFIG_PPC32))
219 seq_printf(m, "Memory\t\t: %d MB\n",
220 (unsigned int)(total_memory / (1024 * 1024)));
223 static int show_cpuinfo(struct seq_file *m, void *v)
225 unsigned long cpu_id = (unsigned long)v - 1;
227 unsigned long proc_freq;
232 pvr = per_cpu(cpu_pvr, cpu_id);
234 pvr = mfspr(SPRN_PVR);
236 maj = (pvr >> 8) & 0xFF;
239 seq_printf(m, "processor\t: %lu\ncpu\t\t: ", cpu_id);
241 if (cur_cpu_spec->pvr_mask && cur_cpu_spec->cpu_name)
242 seq_puts(m, cur_cpu_spec->cpu_name);
244 seq_printf(m, "unknown (%08x)", pvr);
246 if (cpu_has_feature(CPU_FTR_ALTIVEC))
247 seq_puts(m, ", altivec supported");
252 if (cpu_has_feature(CPU_FTR_TAU)) {
253 if (IS_ENABLED(CONFIG_TAU_AVERAGE)) {
254 /* more straightforward, but potentially misleading */
255 seq_printf(m, "temperature \t: %u C (uncalibrated)\n",
258 /* show the actual temp sensor range */
260 temp = cpu_temp_both(cpu_id);
261 seq_printf(m, "temperature \t: %u-%u C (uncalibrated)\n",
262 temp & 0xff, temp >> 16);
265 #endif /* CONFIG_TAU */
268 * Platforms that have variable clock rates, should implement
269 * the method ppc_md.get_proc_freq() that reports the clock
270 * rate of a given cpu. The rest can use ppc_proc_freq to
271 * report the clock rate that is same across all cpus.
273 if (ppc_md.get_proc_freq)
274 proc_freq = ppc_md.get_proc_freq(cpu_id);
276 proc_freq = ppc_proc_freq;
279 seq_printf(m, "clock\t\t: %lu.%06luMHz\n",
280 proc_freq / 1000000, proc_freq % 1000000);
282 if (ppc_md.show_percpuinfo != NULL)
283 ppc_md.show_percpuinfo(m, cpu_id);
285 /* If we are a Freescale core do a simple check so
286 * we dont have to keep adding cases in the future */
287 if (PVR_VER(pvr) & 0x8000) {
288 switch (PVR_VER(pvr)) {
289 case 0x8000: /* 7441/7450/7451, Voyager */
290 case 0x8001: /* 7445/7455, Apollo 6 */
291 case 0x8002: /* 7447/7457, Apollo 7 */
292 case 0x8003: /* 7447A, Apollo 7 PM */
293 case 0x8004: /* 7448, Apollo 8 */
294 case 0x800c: /* 7410, Nitro */
295 maj = ((pvr >> 8) & 0xF);
298 default: /* e500/book-e */
304 switch (PVR_VER(pvr)) {
305 case 0x1008: /* 740P/750P ?? */
306 maj = ((pvr >> 8) & 0xFF) - 1;
309 case 0x004e: /* POWER9 bits 12-15 give chip type */
310 case 0x0080: /* POWER10 bit 12 gives SMT8/4 */
311 maj = (pvr >> 8) & 0x0F;
315 maj = (pvr >> 8) & 0xFF;
321 seq_printf(m, "revision\t: %hd.%hd (pvr %04x %04x)\n",
322 maj, min, PVR_VER(pvr), PVR_REV(pvr));
324 if (IS_ENABLED(CONFIG_PPC32))
325 seq_printf(m, "bogomips\t: %lu.%02lu\n", loops_per_jiffy / (500000 / HZ),
326 (loops_per_jiffy / (5000 / HZ)) % 100);
330 /* If this is the last cpu, print the summary */
331 if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
332 show_cpuinfo_summary(m);
337 static void *c_start(struct seq_file *m, loff_t *pos)
339 if (*pos == 0) /* just in case, cpu 0 is not the first */
340 *pos = cpumask_first(cpu_online_mask);
342 *pos = cpumask_next(*pos - 1, cpu_online_mask);
343 if ((*pos) < nr_cpu_ids)
344 return (void *)(unsigned long)(*pos + 1);
348 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
351 return c_start(m, pos);
354 static void c_stop(struct seq_file *m, void *v)
358 const struct seq_operations cpuinfo_op = {
362 .show = show_cpuinfo,
365 void __init check_for_initrd(void)
367 #ifdef CONFIG_BLK_DEV_INITRD
368 DBG(" -> check_for_initrd() initrd_start=0x%lx initrd_end=0x%lx\n",
369 initrd_start, initrd_end);
371 /* If we were passed an initrd, set the ROOT_DEV properly if the values
372 * look sensible. If not, clear initrd reference.
374 if (is_kernel_addr(initrd_start) && is_kernel_addr(initrd_end) &&
375 initrd_end > initrd_start)
376 ROOT_DEV = Root_RAM0;
378 initrd_start = initrd_end = 0;
381 pr_info("Found initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
383 DBG(" <- check_for_initrd()\n");
384 #endif /* CONFIG_BLK_DEV_INITRD */
389 int threads_per_core, threads_per_subcore, threads_shift __read_mostly;
390 cpumask_t threads_core_mask __read_mostly;
391 EXPORT_SYMBOL_GPL(threads_per_core);
392 EXPORT_SYMBOL_GPL(threads_per_subcore);
393 EXPORT_SYMBOL_GPL(threads_shift);
394 EXPORT_SYMBOL_GPL(threads_core_mask);
396 static void __init cpu_init_thread_core_maps(int tpc)
400 threads_per_core = tpc;
401 threads_per_subcore = tpc;
402 cpumask_clear(&threads_core_mask);
404 /* This implementation only supports power of 2 number of threads
405 * for simplicity and performance
407 threads_shift = ilog2(tpc);
408 BUG_ON(tpc != (1 << threads_shift));
410 for (i = 0; i < tpc; i++)
411 cpumask_set_cpu(i, &threads_core_mask);
413 printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n",
414 tpc, tpc > 1 ? "s" : "");
415 printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift);
419 u32 *cpu_to_phys_id = NULL;
422 * setup_cpu_maps - initialize the following cpu maps:
426 * Having the possible map set up early allows us to restrict allocations
427 * of things like irqstacks to nr_cpu_ids rather than NR_CPUS.
429 * We do not initialize the online map here; cpus set their own bits in
430 * cpu_online_mask as they come up.
432 * This function is valid only for Open Firmware systems. finish_device_tree
433 * must be called before using this.
435 * While we're here, we may as well set the "physical" cpu ids in the paca.
437 * NOTE: This must match the parsing done in early_init_dt_scan_cpus.
439 void __init smp_setup_cpu_maps(void)
441 struct device_node *dn;
445 DBG("smp_setup_cpu_maps()\n");
447 cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32),
450 panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
451 __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32));
453 for_each_node_by_type(dn, "cpu") {
454 const __be32 *intserv;
458 DBG(" * %pOF...\n", dn);
460 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
463 DBG(" ibm,ppc-interrupt-server#s -> %d threads\n",
466 DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n");
467 intserv = of_get_property(dn, "reg", &len);
469 cpu_be = cpu_to_be32(cpu);
470 /* XXX: what is this? uninitialized?? */
471 intserv = &cpu_be; /* assume logical == phys */
476 nthreads = len / sizeof(int);
478 for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) {
481 DBG(" thread %d -> cpu %d (hard id %d)\n",
482 j, cpu, be32_to_cpu(intserv[j]));
484 avail = of_device_is_available(dn);
486 avail = !of_property_match_string(dn,
487 "enable-method", "spin-table");
489 set_cpu_present(cpu, avail);
490 set_cpu_possible(cpu, true);
491 cpu_to_phys_id[cpu] = be32_to_cpu(intserv[j]);
495 if (cpu >= nr_cpu_ids) {
501 /* If no SMT supported, nthreads is forced to 1 */
502 if (!cpu_has_feature(CPU_FTR_SMT)) {
503 DBG(" SMT disabled ! nthreads forced to 1\n");
509 * On pSeries LPAR, we need to know how many cpus
510 * could possibly be added to this partition.
512 if (firmware_has_feature(FW_FEATURE_LPAR) &&
513 (dn = of_find_node_by_path("/rtas"))) {
514 int num_addr_cell, num_size_cell, maxcpus;
517 num_addr_cell = of_n_addr_cells(dn);
518 num_size_cell = of_n_size_cells(dn);
520 ireg = of_get_property(dn, "ibm,lrdr-capacity", NULL);
525 maxcpus = be32_to_cpup(ireg + num_addr_cell + num_size_cell);
527 /* Double maxcpus for processors which have SMT capability */
528 if (cpu_has_feature(CPU_FTR_SMT))
531 if (maxcpus > nr_cpu_ids) {
533 "Partition configured for %d cpus, "
534 "operating system maximum is %u.\n",
535 maxcpus, nr_cpu_ids);
536 maxcpus = nr_cpu_ids;
538 printk(KERN_INFO "Partition configured for %d cpus.\n",
541 for (cpu = 0; cpu < maxcpus; cpu++)
542 set_cpu_possible(cpu, true);
546 vdso_data->processorCount = num_present_cpus();
547 #endif /* CONFIG_PPC64 */
549 /* Initialize CPU <=> thread mapping/
551 * WARNING: We assume that the number of threads is the same for
552 * every CPU in the system. If that is not the case, then some code
553 * here will have to be reworked
555 cpu_init_thread_core_maps(nthreads);
557 /* Now that possible cpus are set, set nr_cpu_ids for later use */
562 #endif /* CONFIG_SMP */
564 #ifdef CONFIG_PCSPKR_PLATFORM
565 static __init int add_pcspkr(void)
567 struct device_node *np;
568 struct platform_device *pd;
571 np = of_find_compatible_node(NULL, NULL, "pnpPNP,100");
576 pd = platform_device_alloc("pcspkr", -1);
580 ret = platform_device_add(pd);
582 platform_device_put(pd);
586 device_initcall(add_pcspkr);
587 #endif /* CONFIG_PCSPKR_PLATFORM */
589 void probe_machine(void)
591 extern struct machdep_calls __machine_desc_start;
592 extern struct machdep_calls __machine_desc_end;
596 * Iterate all ppc_md structures until we find the proper
597 * one for the current machine type
599 DBG("Probing machine type ...\n");
602 * Check ppc_md is empty, if not we have a bug, ie, we setup an
603 * entry before probe_machine() which will be overwritten
605 for (i = 0; i < (sizeof(ppc_md) / sizeof(void *)); i++) {
606 if (((void **)&ppc_md)[i]) {
607 printk(KERN_ERR "Entry %d in ppc_md non empty before"
608 " machine probe !\n", i);
612 for (machine_id = &__machine_desc_start;
613 machine_id < &__machine_desc_end;
615 DBG(" %s ...", machine_id->name);
616 memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
617 if (ppc_md.probe()) {
623 /* What can we do if we didn't find ? */
624 if (machine_id >= &__machine_desc_end) {
625 pr_err("No suitable machine description found !\n");
629 printk(KERN_INFO "Using %s machine description\n", ppc_md.name);
632 /* Match a class of boards, not a specific device configuration. */
633 int check_legacy_ioport(unsigned long base_port)
635 struct device_node *parent, *np = NULL;
640 if (!(np = of_find_compatible_node(NULL, NULL, "pnpPNP,303")))
641 np = of_find_compatible_node(NULL, NULL, "pnpPNP,f03");
643 parent = of_get_parent(np);
645 of_i8042_kbd_irq = irq_of_parse_and_map(parent, 0);
646 if (!of_i8042_kbd_irq)
647 of_i8042_kbd_irq = 1;
649 of_i8042_aux_irq = irq_of_parse_and_map(parent, 1);
650 if (!of_i8042_aux_irq)
651 of_i8042_aux_irq = 12;
657 np = of_find_node_by_type(NULL, "8042");
658 /* Pegasos has no device_type on its 8042 node, look for the
661 np = of_find_node_by_name(NULL, "8042");
663 of_i8042_kbd_irq = 1;
664 of_i8042_aux_irq = 12;
667 case FDC_BASE: /* FDC1 */
668 np = of_find_node_by_type(NULL, "fdc");
671 /* ipmi is supposed to fail here */
676 parent = of_get_parent(np);
678 if (of_node_is_type(parent, "isa"))
685 EXPORT_SYMBOL(check_legacy_ioport);
687 static int ppc_panic_event(struct notifier_block *this,
688 unsigned long event, void *ptr)
691 * panic does a local_irq_disable, but we really
692 * want interrupts to be hard disabled.
697 * If firmware-assisted dump has been registered then trigger
698 * firmware-assisted dump and let firmware handle everything else.
700 crash_fadump(NULL, ptr);
702 ppc_md.panic(ptr); /* May not return */
706 static struct notifier_block ppc_panic_block = {
707 .notifier_call = ppc_panic_event,
708 .priority = INT_MIN /* may not return; must be done last */
712 * Dump out kernel offset information on panic.
714 static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
717 pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
718 kaslr_offset(), KERNELBASE);
723 static struct notifier_block kernel_offset_notifier = {
724 .notifier_call = dump_kernel_offset
727 void __init setup_panic(void)
729 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0)
730 atomic_notifier_chain_register(&panic_notifier_list,
731 &kernel_offset_notifier);
733 /* PPC64 always does a hard irq disable in its panic handler */
734 if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic)
736 atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block);
739 #ifdef CONFIG_CHECK_CACHE_COHERENCY
741 * For platforms that have configurable cache-coherency. This function
742 * checks that the cache coherency setting of the kernel matches the setting
743 * left by the firmware, as indicated in the device tree. Since a mismatch
744 * will eventually result in DMA failures, we print * and error and call
745 * BUG() in that case.
748 #define KERNEL_COHERENCY (!IS_ENABLED(CONFIG_NOT_COHERENT_CACHE))
750 static int __init check_cache_coherency(void)
752 struct device_node *np;
754 bool devtree_coherency;
756 np = of_find_node_by_path("/");
757 prop = of_get_property(np, "coherency-off", NULL);
760 devtree_coherency = prop ? false : true;
762 if (devtree_coherency != KERNEL_COHERENCY) {
764 "kernel coherency:%s != device tree_coherency:%s\n",
765 KERNEL_COHERENCY ? "on" : "off",
766 devtree_coherency ? "on" : "off");
773 late_initcall(check_cache_coherency);
774 #endif /* CONFIG_CHECK_CACHE_COHERENCY */
776 #ifdef CONFIG_DEBUG_FS
777 struct dentry *powerpc_debugfs_root;
778 EXPORT_SYMBOL(powerpc_debugfs_root);
780 static int powerpc_debugfs_init(void)
782 powerpc_debugfs_root = debugfs_create_dir("powerpc", NULL);
785 arch_initcall(powerpc_debugfs_init);
788 void ppc_printk_progress(char *s, unsigned short hex)
793 static __init void print_system_info(void)
795 pr_info("-----------------------------------------------------\n");
796 pr_info("phys_mem_size = 0x%llx\n",
797 (unsigned long long)memblock_phys_mem_size());
799 pr_info("dcache_bsize = 0x%x\n", dcache_bsize);
800 pr_info("icache_bsize = 0x%x\n", icache_bsize);
802 pr_info("cpu_features = 0x%016lx\n", cur_cpu_spec->cpu_features);
803 pr_info(" possible = 0x%016lx\n",
804 (unsigned long)CPU_FTRS_POSSIBLE);
805 pr_info(" always = 0x%016lx\n",
806 (unsigned long)CPU_FTRS_ALWAYS);
807 pr_info("cpu_user_features = 0x%08x 0x%08x\n",
808 cur_cpu_spec->cpu_user_features,
809 cur_cpu_spec->cpu_user_features2);
810 pr_info("mmu_features = 0x%08x\n", cur_cpu_spec->mmu_features);
812 pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
813 #ifdef CONFIG_PPC_BOOK3S
814 pr_info("vmalloc start = 0x%lx\n", KERN_VIRT_START);
815 pr_info("IO start = 0x%lx\n", KERN_IO_START);
816 pr_info("vmemmap start = 0x%lx\n", (unsigned long)vmemmap);
820 if (!early_radix_enabled())
821 print_system_hash_info();
823 if (PHYSICAL_START > 0)
824 pr_info("physical_start = 0x%llx\n",
825 (unsigned long long)PHYSICAL_START);
826 pr_info("-----------------------------------------------------\n");
830 static void __init smp_setup_pacas(void)
834 for_each_possible_cpu(cpu) {
835 if (cpu == smp_processor_id())
838 set_hard_smp_processor_id(cpu, cpu_to_phys_id[cpu]);
841 memblock_free(__pa(cpu_to_phys_id), nr_cpu_ids * sizeof(u32));
842 cpu_to_phys_id = NULL;
847 * Called into from start_kernel this initializes memblock, which is used
848 * to manage page allocation until mem_init is called.
850 void __init setup_arch(char **cmdline_p)
854 *cmdline_p = boot_command_line;
856 /* Set a half-reasonable default so udelay does something sensible */
857 loops_per_jiffy = 500000000 / HZ;
859 /* Unflatten the device-tree passed by prom_init or kexec */
860 unflatten_device_tree();
863 * Initialize cache line/block info from device-tree (on ppc64) or
864 * just cputable (on ppc32).
866 initialize_cache_info();
868 /* Initialize RTAS if available. */
871 /* Check if we have an initrd provided via the device-tree. */
874 /* Probe the machine type, establish ppc_md. */
877 /* Setup panic notifier if requested by the platform. */
881 * Configure ppc_md.power_save (ppc32 only, 64-bit machines do
882 * it from their respective probe() function.
886 /* Discover standard serial ports. */
887 find_legacy_serial_ports();
889 /* Register early console with the printk subsystem. */
890 register_early_udbg_console();
892 /* Setup the various CPU maps based on the device-tree. */
893 smp_setup_cpu_maps();
895 /* Initialize xmon. */
898 /* Check the SMT related command line arguments (ppc64). */
901 /* Parse memory topology */
902 mem_topology_setup();
905 * Release secondary cpus out of their spinloops at 0x60 now that
906 * we can map physical -> logical CPU ids.
908 * Freescale Book3e parts spin in a loop provided by firmware,
909 * so smp_release_cpus() does nothing for them.
914 /* On BookE, setup per-core TLB data structures. */
915 setup_tlb_core_data();
918 /* Print various info about the machine that has been gathered so far. */
921 /* Reserve large chunks of memory for use by CMA for KVM. */
924 /* Reserve large chunks of memory for us by CMA for hugetlb */
925 gigantic_hugetlb_cma_reserve();
927 klp_init_thread_info(&init_task);
929 setup_initial_init_mm(_stext, _etext, _edata, _end);
931 mm_iommu_init(&init_mm);
932 irqstack_early_init();
933 exc_lvl_early_init();
934 emergency_stack_init();
941 early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
943 if (ppc_md.setup_arch)
946 setup_barrier_nospec();
951 /* Initialize the MMU context management stuff. */
954 /* Interrupt code needs to be 64K-aligned. */
955 if (IS_ENABLED(CONFIG_PPC64) && (unsigned long)_stext & 0xffff)
956 panic("Kernelbase not 64K-aligned (0x%lx)!\n",
957 (unsigned long)_stext);