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/printk.h>
22 #include <linux/seq_file.h>
23 #include <linux/ioport.h>
24 #include <linux/console.h>
25 #include <linux/screen_info.h>
26 #include <linux/root_dev.h>
27 #include <linux/cpu.h>
28 #include <linux/unistd.h>
29 #include <linux/seq_buf.h>
30 #include <linux/serial.h>
31 #include <linux/serial_8250.h>
32 #include <linux/percpu.h>
33 #include <linux/memblock.h>
34 #include <linux/of_irq.h>
35 #include <linux/of_fdt.h>
36 #include <linux/of_platform.h>
37 #include <linux/hugetlb.h>
38 #include <linux/pgtable.h>
41 #include <asm/processor.h>
42 #include <asm/vdso_datapage.h>
45 #include <asm/machdep.h>
47 #include <asm/cputable.h>
48 #include <asm/sections.h>
49 #include <asm/firmware.h>
50 #include <asm/btext.h>
51 #include <asm/nvram.h>
52 #include <asm/setup.h>
54 #include <asm/iommu.h>
55 #include <asm/serial.h>
56 #include <asm/cache.h>
60 #include <asm/cputhreads.h>
61 #include <mm/mmu_decl.h>
62 #include <asm/archrandom.h>
63 #include <asm/fadump.h>
65 #include <asm/hugetlb.h>
66 #include <asm/livepatch.h>
67 #include <asm/mmu_context.h>
68 #include <asm/cpu_has_feature.h>
69 #include <asm/kasan.h>
75 #define DBG(fmt...) udbg_printf(fmt)
80 /* The main machine-dep calls structure
82 struct machdep_calls ppc_md;
83 EXPORT_SYMBOL(ppc_md);
84 struct machdep_calls *machine_id;
85 EXPORT_SYMBOL(machine_id);
88 EXPORT_SYMBOL_GPL(boot_cpuid);
91 int boot_cpu_hwid = -1;
95 * These are used in binfmt_elf.c to put aux entries on the stack
96 * for each elf executable being started.
102 * This still seems to be needed... -- paulus
104 struct screen_info screen_info = {
107 .orig_video_cols = 80,
108 .orig_video_lines = 25,
109 .orig_video_isVGA = 1,
110 .orig_video_points = 16
112 #if defined(CONFIG_FB_VGA16_MODULE)
113 EXPORT_SYMBOL(screen_info);
116 /* Variables required to store legacy IO irq routing */
117 int of_i8042_kbd_irq;
118 EXPORT_SYMBOL_GPL(of_i8042_kbd_irq);
119 int of_i8042_aux_irq;
120 EXPORT_SYMBOL_GPL(of_i8042_aux_irq);
122 #ifdef __DO_IRQ_CANON
123 /* XXX should go elsewhere eventually */
124 int ppc_do_canonicalize_irqs;
125 EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
128 #ifdef CONFIG_CRASH_CORE
129 /* This keeps a track of which one is the crashing cpu. */
130 int crashing_cpu = -1;
133 /* also used by kexec */
134 void machine_shutdown(void)
137 * if fadump is active, cleanup the fadump registration before we
142 if (ppc_md.machine_shutdown)
143 ppc_md.machine_shutdown();
146 static void machine_hang(void)
148 pr_emerg("System Halted, OK to turn off power\n");
154 void machine_restart(char *cmd)
162 do_kernel_restart(cmd);
168 void machine_power_off(void)
171 do_kernel_power_off();
175 /* Used by the G5 thermal driver */
176 EXPORT_SYMBOL_GPL(machine_power_off);
178 void (*pm_power_off)(void);
179 EXPORT_SYMBOL_GPL(pm_power_off);
181 size_t __must_check arch_get_random_seed_longs(unsigned long *v, size_t max_longs)
183 if (max_longs && ppc_md.get_random_seed && ppc_md.get_random_seed(v))
187 EXPORT_SYMBOL(arch_get_random_seed_longs);
189 void machine_halt(void)
200 DEFINE_PER_CPU(unsigned int, cpu_pvr);
203 static void show_cpuinfo_summary(struct seq_file *m)
205 struct device_node *root;
206 const char *model = NULL;
207 unsigned long bogosum = 0;
210 if (IS_ENABLED(CONFIG_SMP) && IS_ENABLED(CONFIG_PPC32)) {
211 for_each_online_cpu(i)
212 bogosum += loops_per_jiffy;
213 seq_printf(m, "total bogomips\t: %lu.%02lu\n",
214 bogosum / (500000 / HZ), bogosum / (5000 / HZ) % 100);
216 seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq);
218 seq_printf(m, "platform\t: %s\n", ppc_md.name);
219 root = of_find_node_by_path("/");
221 model = of_get_property(root, "model", NULL);
223 seq_printf(m, "model\t\t: %s\n", model);
226 if (ppc_md.show_cpuinfo != NULL)
227 ppc_md.show_cpuinfo(m);
229 /* Display the amount of memory */
230 if (IS_ENABLED(CONFIG_PPC32))
231 seq_printf(m, "Memory\t\t: %d MB\n",
232 (unsigned int)(total_memory / (1024 * 1024)));
235 static int show_cpuinfo(struct seq_file *m, void *v)
237 unsigned long cpu_id = (unsigned long)v - 1;
239 unsigned long proc_freq;
244 pvr = per_cpu(cpu_pvr, cpu_id);
246 pvr = mfspr(SPRN_PVR);
248 maj = (pvr >> 8) & 0xFF;
251 seq_printf(m, "processor\t: %lu\ncpu\t\t: ", cpu_id);
253 if (cur_cpu_spec->pvr_mask && cur_cpu_spec->cpu_name)
254 seq_puts(m, cur_cpu_spec->cpu_name);
256 seq_printf(m, "unknown (%08x)", pvr);
258 if (cpu_has_feature(CPU_FTR_ALTIVEC))
259 seq_puts(m, ", altivec supported");
264 if (cpu_has_feature(CPU_FTR_TAU)) {
265 if (IS_ENABLED(CONFIG_TAU_AVERAGE)) {
266 /* more straightforward, but potentially misleading */
267 seq_printf(m, "temperature \t: %u C (uncalibrated)\n",
270 /* show the actual temp sensor range */
272 temp = cpu_temp_both(cpu_id);
273 seq_printf(m, "temperature \t: %u-%u C (uncalibrated)\n",
274 temp & 0xff, temp >> 16);
277 #endif /* CONFIG_TAU */
280 * Platforms that have variable clock rates, should implement
281 * the method ppc_md.get_proc_freq() that reports the clock
282 * rate of a given cpu. The rest can use ppc_proc_freq to
283 * report the clock rate that is same across all cpus.
285 if (ppc_md.get_proc_freq)
286 proc_freq = ppc_md.get_proc_freq(cpu_id);
288 proc_freq = ppc_proc_freq;
291 seq_printf(m, "clock\t\t: %lu.%06luMHz\n",
292 proc_freq / 1000000, proc_freq % 1000000);
294 /* If we are a Freescale core do a simple check so
295 * we don't have to keep adding cases in the future */
296 if (PVR_VER(pvr) & 0x8000) {
297 switch (PVR_VER(pvr)) {
298 case 0x8000: /* 7441/7450/7451, Voyager */
299 case 0x8001: /* 7445/7455, Apollo 6 */
300 case 0x8002: /* 7447/7457, Apollo 7 */
301 case 0x8003: /* 7447A, Apollo 7 PM */
302 case 0x8004: /* 7448, Apollo 8 */
303 case 0x800c: /* 7410, Nitro */
304 maj = ((pvr >> 8) & 0xF);
307 default: /* e500/book-e */
313 switch (PVR_VER(pvr)) {
314 case 0x1008: /* 740P/750P ?? */
315 maj = ((pvr >> 8) & 0xFF) - 1;
318 case 0x004e: /* POWER9 bits 12-15 give chip type */
319 case 0x0080: /* POWER10 bit 12 gives SMT8/4 */
320 maj = (pvr >> 8) & 0x0F;
324 maj = (pvr >> 8) & 0xFF;
330 seq_printf(m, "revision\t: %hd.%hd (pvr %04x %04x)\n",
331 maj, min, PVR_VER(pvr), PVR_REV(pvr));
333 if (IS_ENABLED(CONFIG_PPC32))
334 seq_printf(m, "bogomips\t: %lu.%02lu\n", loops_per_jiffy / (500000 / HZ),
335 (loops_per_jiffy / (5000 / HZ)) % 100);
339 /* If this is the last cpu, print the summary */
340 if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids)
341 show_cpuinfo_summary(m);
346 static void *c_start(struct seq_file *m, loff_t *pos)
348 if (*pos == 0) /* just in case, cpu 0 is not the first */
349 *pos = cpumask_first(cpu_online_mask);
351 *pos = cpumask_next(*pos - 1, cpu_online_mask);
352 if ((*pos) < nr_cpu_ids)
353 return (void *)(unsigned long)(*pos + 1);
357 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
360 return c_start(m, pos);
363 static void c_stop(struct seq_file *m, void *v)
367 const struct seq_operations cpuinfo_op = {
371 .show = show_cpuinfo,
374 void __init check_for_initrd(void)
376 #ifdef CONFIG_BLK_DEV_INITRD
377 DBG(" -> check_for_initrd() initrd_start=0x%lx initrd_end=0x%lx\n",
378 initrd_start, initrd_end);
380 /* If we were passed an initrd, set the ROOT_DEV properly if the values
381 * look sensible. If not, clear initrd reference.
383 if (is_kernel_addr(initrd_start) && is_kernel_addr(initrd_end) &&
384 initrd_end > initrd_start)
385 ROOT_DEV = Root_RAM0;
387 initrd_start = initrd_end = 0;
390 pr_info("Found initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
392 DBG(" <- check_for_initrd()\n");
393 #endif /* CONFIG_BLK_DEV_INITRD */
398 int threads_per_core, threads_per_subcore, threads_shift __read_mostly;
399 cpumask_t threads_core_mask __read_mostly;
400 EXPORT_SYMBOL_GPL(threads_per_core);
401 EXPORT_SYMBOL_GPL(threads_per_subcore);
402 EXPORT_SYMBOL_GPL(threads_shift);
403 EXPORT_SYMBOL_GPL(threads_core_mask);
405 static void __init cpu_init_thread_core_maps(int tpc)
409 threads_per_core = tpc;
410 threads_per_subcore = tpc;
411 cpumask_clear(&threads_core_mask);
413 /* This implementation only supports power of 2 number of threads
414 * for simplicity and performance
416 threads_shift = ilog2(tpc);
417 BUG_ON(tpc != (1 << threads_shift));
419 for (i = 0; i < tpc; i++)
420 cpumask_set_cpu(i, &threads_core_mask);
422 printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n",
423 tpc, tpc > 1 ? "s" : "");
424 printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift);
428 u32 *cpu_to_phys_id = NULL;
431 * setup_cpu_maps - initialize the following cpu maps:
435 * Having the possible map set up early allows us to restrict allocations
436 * of things like irqstacks to nr_cpu_ids rather than NR_CPUS.
438 * We do not initialize the online map here; cpus set their own bits in
439 * cpu_online_mask as they come up.
441 * This function is valid only for Open Firmware systems. finish_device_tree
442 * must be called before using this.
444 * While we're here, we may as well set the "physical" cpu ids in the paca.
446 * NOTE: This must match the parsing done in early_init_dt_scan_cpus.
448 void __init smp_setup_cpu_maps(void)
450 struct device_node *dn;
454 DBG("smp_setup_cpu_maps()\n");
456 cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32),
459 panic("%s: Failed to allocate %zu bytes align=0x%zx\n",
460 __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32));
462 for_each_node_by_type(dn, "cpu") {
463 const __be32 *intserv;
467 DBG(" * %pOF...\n", dn);
469 intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
472 DBG(" ibm,ppc-interrupt-server#s -> %lu threads\n",
473 (len / sizeof(int)));
475 DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n");
476 intserv = of_get_property(dn, "reg", &len);
478 cpu_be = cpu_to_be32(cpu);
479 /* XXX: what is this? uninitialized?? */
480 intserv = &cpu_be; /* assume logical == phys */
485 nthreads = len / sizeof(int);
487 for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) {
490 DBG(" thread %d -> cpu %d (hard id %d)\n",
491 j, cpu, be32_to_cpu(intserv[j]));
493 avail = of_device_is_available(dn);
495 avail = !of_property_match_string(dn,
496 "enable-method", "spin-table");
498 set_cpu_present(cpu, avail);
499 set_cpu_possible(cpu, true);
500 cpu_to_phys_id[cpu] = be32_to_cpu(intserv[j]);
504 if (cpu >= nr_cpu_ids) {
510 /* If no SMT supported, nthreads is forced to 1 */
511 if (!cpu_has_feature(CPU_FTR_SMT)) {
512 DBG(" SMT disabled ! nthreads forced to 1\n");
518 * On pSeries LPAR, we need to know how many cpus
519 * could possibly be added to this partition.
521 if (firmware_has_feature(FW_FEATURE_LPAR) &&
522 (dn = of_find_node_by_path("/rtas"))) {
523 int num_addr_cell, num_size_cell, maxcpus;
526 num_addr_cell = of_n_addr_cells(dn);
527 num_size_cell = of_n_size_cells(dn);
529 ireg = of_get_property(dn, "ibm,lrdr-capacity", NULL);
534 maxcpus = be32_to_cpup(ireg + num_addr_cell + num_size_cell);
536 /* Double maxcpus for processors which have SMT capability */
537 if (cpu_has_feature(CPU_FTR_SMT))
540 if (maxcpus > nr_cpu_ids) {
542 "Partition configured for %d cpus, "
543 "operating system maximum is %u.\n",
544 maxcpus, nr_cpu_ids);
545 maxcpus = nr_cpu_ids;
547 printk(KERN_INFO "Partition configured for %d cpus.\n",
550 for (cpu = 0; cpu < maxcpus; cpu++)
551 set_cpu_possible(cpu, true);
555 vdso_data->processorCount = num_present_cpus();
556 #endif /* CONFIG_PPC64 */
558 /* Initialize CPU <=> thread mapping/
560 * WARNING: We assume that the number of threads is the same for
561 * every CPU in the system. If that is not the case, then some code
562 * here will have to be reworked
564 cpu_init_thread_core_maps(nthreads);
566 /* Now that possible cpus are set, set nr_cpu_ids for later use */
571 #endif /* CONFIG_SMP */
573 #ifdef CONFIG_PCSPKR_PLATFORM
574 static __init int add_pcspkr(void)
576 struct device_node *np;
577 struct platform_device *pd;
580 np = of_find_compatible_node(NULL, NULL, "pnpPNP,100");
585 pd = platform_device_alloc("pcspkr", -1);
589 ret = platform_device_add(pd);
591 platform_device_put(pd);
595 device_initcall(add_pcspkr);
596 #endif /* CONFIG_PCSPKR_PLATFORM */
598 static char ppc_hw_desc_buf[128] __initdata;
600 struct seq_buf ppc_hw_desc __initdata = {
601 .buffer = ppc_hw_desc_buf,
602 .size = sizeof(ppc_hw_desc_buf),
607 static __init void probe_machine(void)
609 extern struct machdep_calls __machine_desc_start;
610 extern struct machdep_calls __machine_desc_end;
614 * Iterate all ppc_md structures until we find the proper
615 * one for the current machine type
617 DBG("Probing machine type ...\n");
620 * Check ppc_md is empty, if not we have a bug, ie, we setup an
621 * entry before probe_machine() which will be overwritten
623 for (i = 0; i < (sizeof(ppc_md) / sizeof(void *)); i++) {
624 if (((void **)&ppc_md)[i]) {
625 printk(KERN_ERR "Entry %d in ppc_md non empty before"
626 " machine probe !\n", i);
630 for (machine_id = &__machine_desc_start;
631 machine_id < &__machine_desc_end;
633 DBG(" %s ...\n", machine_id->name);
634 if (machine_id->compatible && !of_machine_is_compatible(machine_id->compatible))
636 memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
637 if (ppc_md.probe && !ppc_md.probe())
639 DBG(" %s match !\n", machine_id->name);
642 /* What can we do if we didn't find ? */
643 if (machine_id >= &__machine_desc_end) {
644 pr_err("No suitable machine description found !\n");
648 // Append the machine name to other info we've gathered
649 seq_buf_puts(&ppc_hw_desc, ppc_md.name);
651 // Set the generic hardware description shown in oopses
652 dump_stack_set_arch_desc(ppc_hw_desc.buffer);
654 pr_info("Hardware name: %s\n", ppc_hw_desc.buffer);
657 /* Match a class of boards, not a specific device configuration. */
658 int check_legacy_ioport(unsigned long base_port)
660 struct device_node *parent, *np = NULL;
665 if (!(np = of_find_compatible_node(NULL, NULL, "pnpPNP,303")))
666 np = of_find_compatible_node(NULL, NULL, "pnpPNP,f03");
668 parent = of_get_parent(np);
670 of_i8042_kbd_irq = irq_of_parse_and_map(parent, 0);
671 if (!of_i8042_kbd_irq)
672 of_i8042_kbd_irq = 1;
674 of_i8042_aux_irq = irq_of_parse_and_map(parent, 1);
675 if (!of_i8042_aux_irq)
676 of_i8042_aux_irq = 12;
682 np = of_find_node_by_type(NULL, "8042");
683 /* Pegasos has no device_type on its 8042 node, look for the
686 np = of_find_node_by_name(NULL, "8042");
688 of_i8042_kbd_irq = 1;
689 of_i8042_aux_irq = 12;
692 case FDC_BASE: /* FDC1 */
693 np = of_find_node_by_type(NULL, "fdc");
696 /* ipmi is supposed to fail here */
701 parent = of_get_parent(np);
703 if (of_node_is_type(parent, "isa"))
710 EXPORT_SYMBOL(check_legacy_ioport);
713 * Panic notifiers setup
715 * We have 3 notifiers for powerpc, each one from a different "nature":
717 * - ppc_panic_fadump_handler() is a hypervisor notifier, which hard-disables
718 * IRQs and deal with the Firmware-Assisted dump, when it is configured;
719 * should run early in the panic path.
721 * - dump_kernel_offset() is an informative notifier, just showing the KASLR
722 * offset if we have RANDOMIZE_BASE set.
724 * - ppc_panic_platform_handler() is a low-level handler that's registered
725 * only if the platform wishes to perform final actions in the panic path,
726 * hence it should run late and might not even return. Currently, only
727 * pseries and ps3 platforms register callbacks.
729 static int ppc_panic_fadump_handler(struct notifier_block *this,
730 unsigned long event, void *ptr)
733 * panic does a local_irq_disable, but we really
734 * want interrupts to be hard disabled.
739 * If firmware-assisted dump has been registered then trigger
740 * its callback and let the firmware handles everything else.
742 crash_fadump(NULL, ptr);
747 static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
750 pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
751 kaslr_offset(), KERNELBASE);
756 static int ppc_panic_platform_handler(struct notifier_block *this,
757 unsigned long event, void *ptr)
760 * This handler is only registered if we have a panic callback
761 * on ppc_md, hence NULL check is not needed.
762 * Also, it may not return, so it runs really late on panic path.
769 static struct notifier_block ppc_fadump_block = {
770 .notifier_call = ppc_panic_fadump_handler,
771 .priority = INT_MAX, /* run early, to notify the firmware ASAP */
774 static struct notifier_block kernel_offset_notifier = {
775 .notifier_call = dump_kernel_offset,
778 static struct notifier_block ppc_panic_block = {
779 .notifier_call = ppc_panic_platform_handler,
780 .priority = INT_MIN, /* may not return; must be done last */
783 void __init setup_panic(void)
785 /* Hard-disables IRQs + deal with FW-assisted dump (fadump) */
786 atomic_notifier_chain_register(&panic_notifier_list,
789 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0)
790 atomic_notifier_chain_register(&panic_notifier_list,
791 &kernel_offset_notifier);
793 /* Low-level platform-specific routines that should run on panic */
795 atomic_notifier_chain_register(&panic_notifier_list,
799 #ifdef CONFIG_CHECK_CACHE_COHERENCY
801 * For platforms that have configurable cache-coherency. This function
802 * checks that the cache coherency setting of the kernel matches the setting
803 * left by the firmware, as indicated in the device tree. Since a mismatch
804 * will eventually result in DMA failures, we print * and error and call
805 * BUG() in that case.
808 #define KERNEL_COHERENCY (!IS_ENABLED(CONFIG_NOT_COHERENT_CACHE))
810 static int __init check_cache_coherency(void)
812 struct device_node *np;
814 bool devtree_coherency;
816 np = of_find_node_by_path("/");
817 prop = of_get_property(np, "coherency-off", NULL);
820 devtree_coherency = prop ? false : true;
822 if (devtree_coherency != KERNEL_COHERENCY) {
824 "kernel coherency:%s != device tree_coherency:%s\n",
825 KERNEL_COHERENCY ? "on" : "off",
826 devtree_coherency ? "on" : "off");
833 late_initcall(check_cache_coherency);
834 #endif /* CONFIG_CHECK_CACHE_COHERENCY */
836 void ppc_printk_progress(char *s, unsigned short hex)
841 static __init void print_system_info(void)
843 pr_info("-----------------------------------------------------\n");
844 pr_info("phys_mem_size = 0x%llx\n",
845 (unsigned long long)memblock_phys_mem_size());
847 pr_info("dcache_bsize = 0x%x\n", dcache_bsize);
848 pr_info("icache_bsize = 0x%x\n", icache_bsize);
850 pr_info("cpu_features = 0x%016lx\n", cur_cpu_spec->cpu_features);
851 pr_info(" possible = 0x%016lx\n",
852 (unsigned long)CPU_FTRS_POSSIBLE);
853 pr_info(" always = 0x%016lx\n",
854 (unsigned long)CPU_FTRS_ALWAYS);
855 pr_info("cpu_user_features = 0x%08x 0x%08x\n",
856 cur_cpu_spec->cpu_user_features,
857 cur_cpu_spec->cpu_user_features2);
858 pr_info("mmu_features = 0x%08x\n", cur_cpu_spec->mmu_features);
860 pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features);
861 #ifdef CONFIG_PPC_BOOK3S
862 pr_info("vmalloc start = 0x%lx\n", KERN_VIRT_START);
863 pr_info("IO start = 0x%lx\n", KERN_IO_START);
864 pr_info("vmemmap start = 0x%lx\n", (unsigned long)vmemmap);
868 if (!early_radix_enabled())
869 print_system_hash_info();
871 if (PHYSICAL_START > 0)
872 pr_info("physical_start = 0x%llx\n",
873 (unsigned long long)PHYSICAL_START);
874 pr_info("-----------------------------------------------------\n");
878 static void __init smp_setup_pacas(void)
882 for_each_possible_cpu(cpu) {
883 if (cpu == smp_processor_id())
886 set_hard_smp_processor_id(cpu, cpu_to_phys_id[cpu]);
889 memblock_free(cpu_to_phys_id, nr_cpu_ids * sizeof(u32));
890 cpu_to_phys_id = NULL;
895 * Called into from start_kernel this initializes memblock, which is used
896 * to manage page allocation until mem_init is called.
898 void __init setup_arch(char **cmdline_p)
902 *cmdline_p = boot_command_line;
904 /* Set a half-reasonable default so udelay does something sensible */
905 loops_per_jiffy = 500000000 / HZ;
907 /* Unflatten the device-tree passed by prom_init or kexec */
908 unflatten_device_tree();
911 * Initialize cache line/block info from device-tree (on ppc64) or
912 * just cputable (on ppc32).
914 initialize_cache_info();
916 /* Initialize RTAS if available. */
919 /* Check if we have an initrd provided via the device-tree. */
922 /* Probe the machine type, establish ppc_md. */
925 /* Setup panic notifier if requested by the platform. */
929 * Configure ppc_md.power_save (ppc32 only, 64-bit machines do
930 * it from their respective probe() function.
934 /* Discover standard serial ports. */
935 find_legacy_serial_ports();
937 /* Register early console with the printk subsystem. */
938 register_early_udbg_console();
940 /* Setup the various CPU maps based on the device-tree. */
941 smp_setup_cpu_maps();
943 /* Initialize xmon. */
946 /* Check the SMT related command line arguments (ppc64). */
949 /* Parse memory topology */
950 mem_topology_setup();
953 * Release secondary cpus out of their spinloops at 0x60 now that
954 * we can map physical -> logical CPU ids.
956 * Freescale Book3e parts spin in a loop provided by firmware,
957 * so smp_release_cpus() does nothing for them.
962 /* On BookE, setup per-core TLB data structures. */
963 setup_tlb_core_data();
966 /* Print various info about the machine that has been gathered so far. */
969 klp_init_thread_info(&init_task);
971 setup_initial_init_mm(_stext, _etext, _edata, _end);
973 mm_iommu_init(&init_mm);
974 irqstack_early_init();
975 exc_lvl_early_init();
976 emergency_stack_init();
984 * Reserve large chunks of memory for use by CMA for KVM and hugetlb. These must
985 * be called after initmem_init(), so that pageblock_order is initialised.
988 gigantic_hugetlb_cma_reserve();
990 early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
992 if (ppc_md.setup_arch)
995 setup_barrier_nospec();
1000 /* Initialize the MMU context management stuff. */
1003 /* Interrupt code needs to be 64K-aligned. */
1004 if (IS_ENABLED(CONFIG_PPC64) && (unsigned long)_stext & 0xffff)
1005 panic("Kernelbase not 64K-aligned (0x%lx)!\n",
1006 (unsigned long)_stext);