// SPDX-License-Identifier: GPL-2.0-or-later /* * Common boot and setup code for both 32-bit and 64-bit. * Extracted from arch/powerpc/kernel/setup_64.c. * * Copyright (C) 2001 PPC64 Team, IBM Corp */ #undef DEBUG #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "setup.h" #ifdef DEBUG #include #define DBG(fmt...) udbg_printf(fmt) #else #define DBG(fmt...) #endif /* The main machine-dep calls structure */ struct machdep_calls ppc_md; EXPORT_SYMBOL(ppc_md); struct machdep_calls *machine_id; EXPORT_SYMBOL(machine_id); int boot_cpuid = -1; EXPORT_SYMBOL_GPL(boot_cpuid); /* * These are used in binfmt_elf.c to put aux entries on the stack * for each elf executable being started. */ int dcache_bsize; int icache_bsize; int ucache_bsize; unsigned long klimit = (unsigned long) _end; /* * This still seems to be needed... -- paulus */ struct screen_info screen_info = { .orig_x = 0, .orig_y = 25, .orig_video_cols = 80, .orig_video_lines = 25, .orig_video_isVGA = 1, .orig_video_points = 16 }; #if defined(CONFIG_FB_VGA16_MODULE) EXPORT_SYMBOL(screen_info); #endif /* Variables required to store legacy IO irq routing */ int of_i8042_kbd_irq; EXPORT_SYMBOL_GPL(of_i8042_kbd_irq); int of_i8042_aux_irq; EXPORT_SYMBOL_GPL(of_i8042_aux_irq); #ifdef __DO_IRQ_CANON /* XXX should go elsewhere eventually */ int ppc_do_canonicalize_irqs; EXPORT_SYMBOL(ppc_do_canonicalize_irqs); #endif #ifdef CONFIG_CRASH_CORE /* This keeps a track of which one is the crashing cpu. */ int crashing_cpu = -1; #endif /* also used by kexec */ void machine_shutdown(void) { /* * if fadump is active, cleanup the fadump registration before we * shutdown. */ fadump_cleanup(); if (ppc_md.machine_shutdown) ppc_md.machine_shutdown(); } static void machine_hang(void) { pr_emerg("System Halted, OK to turn off power\n"); local_irq_disable(); while (1) ; } void machine_restart(char *cmd) { machine_shutdown(); if (ppc_md.restart) ppc_md.restart(cmd); smp_send_stop(); do_kernel_restart(cmd); mdelay(1000); machine_hang(); } void machine_power_off(void) { machine_shutdown(); if (pm_power_off) pm_power_off(); smp_send_stop(); machine_hang(); } /* Used by the G5 thermal driver */ EXPORT_SYMBOL_GPL(machine_power_off); void (*pm_power_off)(void); EXPORT_SYMBOL_GPL(pm_power_off); void machine_halt(void) { machine_shutdown(); if (ppc_md.halt) ppc_md.halt(); smp_send_stop(); machine_hang(); } #ifdef CONFIG_SMP DEFINE_PER_CPU(unsigned int, cpu_pvr); #endif static void show_cpuinfo_summary(struct seq_file *m) { struct device_node *root; const char *model = NULL; unsigned long bogosum = 0; int i; if (IS_ENABLED(CONFIG_SMP) && IS_ENABLED(CONFIG_PPC32)) { for_each_online_cpu(i) bogosum += loops_per_jiffy; seq_printf(m, "total bogomips\t: %lu.%02lu\n", bogosum / (500000 / HZ), bogosum / (5000 / HZ) % 100); } seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq); if (ppc_md.name) seq_printf(m, "platform\t: %s\n", ppc_md.name); root = of_find_node_by_path("/"); if (root) model = of_get_property(root, "model", NULL); if (model) seq_printf(m, "model\t\t: %s\n", model); of_node_put(root); if (ppc_md.show_cpuinfo != NULL) ppc_md.show_cpuinfo(m); /* Display the amount of memory */ if (IS_ENABLED(CONFIG_PPC32)) seq_printf(m, "Memory\t\t: %d MB\n", (unsigned int)(total_memory / (1024 * 1024))); } static int show_cpuinfo(struct seq_file *m, void *v) { unsigned long cpu_id = (unsigned long)v - 1; unsigned int pvr; unsigned long proc_freq; unsigned short maj; unsigned short min; #ifdef CONFIG_SMP pvr = per_cpu(cpu_pvr, cpu_id); #else pvr = mfspr(SPRN_PVR); #endif maj = (pvr >> 8) & 0xFF; min = pvr & 0xFF; seq_printf(m, "processor\t: %lu\n", cpu_id); seq_printf(m, "cpu\t\t: "); if (cur_cpu_spec->pvr_mask && cur_cpu_spec->cpu_name) seq_printf(m, "%s", cur_cpu_spec->cpu_name); else seq_printf(m, "unknown (%08x)", pvr); if (cpu_has_feature(CPU_FTR_ALTIVEC)) seq_printf(m, ", altivec supported"); seq_printf(m, "\n"); #ifdef CONFIG_TAU if (cpu_has_feature(CPU_FTR_TAU)) { if (IS_ENABLED(CONFIG_TAU_AVERAGE)) { /* more straightforward, but potentially misleading */ seq_printf(m, "temperature \t: %u C (uncalibrated)\n", cpu_temp(cpu_id)); } else { /* show the actual temp sensor range */ u32 temp; temp = cpu_temp_both(cpu_id); seq_printf(m, "temperature \t: %u-%u C (uncalibrated)\n", temp & 0xff, temp >> 16); } } #endif /* CONFIG_TAU */ /* * Platforms that have variable clock rates, should implement * the method ppc_md.get_proc_freq() that reports the clock * rate of a given cpu. The rest can use ppc_proc_freq to * report the clock rate that is same across all cpus. */ if (ppc_md.get_proc_freq) proc_freq = ppc_md.get_proc_freq(cpu_id); else proc_freq = ppc_proc_freq; if (proc_freq) seq_printf(m, "clock\t\t: %lu.%06luMHz\n", proc_freq / 1000000, proc_freq % 1000000); if (ppc_md.show_percpuinfo != NULL) ppc_md.show_percpuinfo(m, cpu_id); /* If we are a Freescale core do a simple check so * we dont have to keep adding cases in the future */ if (PVR_VER(pvr) & 0x8000) { switch (PVR_VER(pvr)) { case 0x8000: /* 7441/7450/7451, Voyager */ case 0x8001: /* 7445/7455, Apollo 6 */ case 0x8002: /* 7447/7457, Apollo 7 */ case 0x8003: /* 7447A, Apollo 7 PM */ case 0x8004: /* 7448, Apollo 8 */ case 0x800c: /* 7410, Nitro */ maj = ((pvr >> 8) & 0xF); min = PVR_MIN(pvr); break; default: /* e500/book-e */ maj = PVR_MAJ(pvr); min = PVR_MIN(pvr); break; } } else { switch (PVR_VER(pvr)) { case 0x1008: /* 740P/750P ?? */ maj = ((pvr >> 8) & 0xFF) - 1; min = pvr & 0xFF; break; case 0x004e: /* POWER9 bits 12-15 give chip type */ case 0x0080: /* POWER10 bit 12 gives SMT8/4 */ maj = (pvr >> 8) & 0x0F; min = pvr & 0xFF; break; default: maj = (pvr >> 8) & 0xFF; min = pvr & 0xFF; break; } } seq_printf(m, "revision\t: %hd.%hd (pvr %04x %04x)\n", maj, min, PVR_VER(pvr), PVR_REV(pvr)); if (IS_ENABLED(CONFIG_PPC32)) seq_printf(m, "bogomips\t: %lu.%02lu\n", loops_per_jiffy / (500000 / HZ), (loops_per_jiffy / (5000 / HZ)) % 100); seq_printf(m, "\n"); /* If this is the last cpu, print the summary */ if (cpumask_next(cpu_id, cpu_online_mask) >= nr_cpu_ids) show_cpuinfo_summary(m); return 0; } static void *c_start(struct seq_file *m, loff_t *pos) { if (*pos == 0) /* just in case, cpu 0 is not the first */ *pos = cpumask_first(cpu_online_mask); else *pos = cpumask_next(*pos - 1, cpu_online_mask); if ((*pos) < nr_cpu_ids) return (void *)(unsigned long)(*pos + 1); return NULL; } static void *c_next(struct seq_file *m, void *v, loff_t *pos) { (*pos)++; return c_start(m, pos); } static void c_stop(struct seq_file *m, void *v) { } const struct seq_operations cpuinfo_op = { .start = c_start, .next = c_next, .stop = c_stop, .show = show_cpuinfo, }; void __init check_for_initrd(void) { #ifdef CONFIG_BLK_DEV_INITRD DBG(" -> check_for_initrd() initrd_start=0x%lx initrd_end=0x%lx\n", initrd_start, initrd_end); /* If we were passed an initrd, set the ROOT_DEV properly if the values * look sensible. If not, clear initrd reference. */ if (is_kernel_addr(initrd_start) && is_kernel_addr(initrd_end) && initrd_end > initrd_start) ROOT_DEV = Root_RAM0; else initrd_start = initrd_end = 0; if (initrd_start) pr_info("Found initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end); DBG(" <- check_for_initrd()\n"); #endif /* CONFIG_BLK_DEV_INITRD */ } #ifdef CONFIG_SMP int threads_per_core, threads_per_subcore, threads_shift __read_mostly; cpumask_t threads_core_mask __read_mostly; EXPORT_SYMBOL_GPL(threads_per_core); EXPORT_SYMBOL_GPL(threads_per_subcore); EXPORT_SYMBOL_GPL(threads_shift); EXPORT_SYMBOL_GPL(threads_core_mask); static void __init cpu_init_thread_core_maps(int tpc) { int i; threads_per_core = tpc; threads_per_subcore = tpc; cpumask_clear(&threads_core_mask); /* This implementation only supports power of 2 number of threads * for simplicity and performance */ threads_shift = ilog2(tpc); BUG_ON(tpc != (1 << threads_shift)); for (i = 0; i < tpc; i++) cpumask_set_cpu(i, &threads_core_mask); printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n", tpc, tpc > 1 ? "s" : ""); printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift); } u32 *cpu_to_phys_id = NULL; /** * setup_cpu_maps - initialize the following cpu maps: * cpu_possible_mask * cpu_present_mask * * Having the possible map set up early allows us to restrict allocations * of things like irqstacks to nr_cpu_ids rather than NR_CPUS. * * We do not initialize the online map here; cpus set their own bits in * cpu_online_mask as they come up. * * This function is valid only for Open Firmware systems. finish_device_tree * must be called before using this. * * While we're here, we may as well set the "physical" cpu ids in the paca. * * NOTE: This must match the parsing done in early_init_dt_scan_cpus. */ void __init smp_setup_cpu_maps(void) { struct device_node *dn; int cpu = 0; int nthreads = 1; DBG("smp_setup_cpu_maps()\n"); cpu_to_phys_id = memblock_alloc(nr_cpu_ids * sizeof(u32), __alignof__(u32)); if (!cpu_to_phys_id) panic("%s: Failed to allocate %zu bytes align=0x%zx\n", __func__, nr_cpu_ids * sizeof(u32), __alignof__(u32)); for_each_node_by_type(dn, "cpu") { const __be32 *intserv; __be32 cpu_be; int j, len; DBG(" * %pOF...\n", dn); intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len); if (intserv) { DBG(" ibm,ppc-interrupt-server#s -> %d threads\n", nthreads); } else { DBG(" no ibm,ppc-interrupt-server#s -> 1 thread\n"); intserv = of_get_property(dn, "reg", &len); if (!intserv) { cpu_be = cpu_to_be32(cpu); /* XXX: what is this? uninitialized?? */ intserv = &cpu_be; /* assume logical == phys */ len = 4; } } nthreads = len / sizeof(int); for (j = 0; j < nthreads && cpu < nr_cpu_ids; j++) { bool avail; DBG(" thread %d -> cpu %d (hard id %d)\n", j, cpu, be32_to_cpu(intserv[j])); avail = of_device_is_available(dn); if (!avail) avail = !of_property_match_string(dn, "enable-method", "spin-table"); set_cpu_present(cpu, avail); set_cpu_possible(cpu, true); cpu_to_phys_id[cpu] = be32_to_cpu(intserv[j]); cpu++; } if (cpu >= nr_cpu_ids) { of_node_put(dn); break; } } /* If no SMT supported, nthreads is forced to 1 */ if (!cpu_has_feature(CPU_FTR_SMT)) { DBG(" SMT disabled ! nthreads forced to 1\n"); nthreads = 1; } #ifdef CONFIG_PPC64 /* * On pSeries LPAR, we need to know how many cpus * could possibly be added to this partition. */ if (firmware_has_feature(FW_FEATURE_LPAR) && (dn = of_find_node_by_path("/rtas"))) { int num_addr_cell, num_size_cell, maxcpus; const __be32 *ireg; num_addr_cell = of_n_addr_cells(dn); num_size_cell = of_n_size_cells(dn); ireg = of_get_property(dn, "ibm,lrdr-capacity", NULL); if (!ireg) goto out; maxcpus = be32_to_cpup(ireg + num_addr_cell + num_size_cell); /* Double maxcpus for processors which have SMT capability */ if (cpu_has_feature(CPU_FTR_SMT)) maxcpus *= nthreads; if (maxcpus > nr_cpu_ids) { printk(KERN_WARNING "Partition configured for %d cpus, " "operating system maximum is %u.\n", maxcpus, nr_cpu_ids); maxcpus = nr_cpu_ids; } else printk(KERN_INFO "Partition configured for %d cpus.\n", maxcpus); for (cpu = 0; cpu < maxcpus; cpu++) set_cpu_possible(cpu, true); out: of_node_put(dn); } vdso_data->processorCount = num_present_cpus(); #endif /* CONFIG_PPC64 */ /* Initialize CPU <=> thread mapping/ * * WARNING: We assume that the number of threads is the same for * every CPU in the system. If that is not the case, then some code * here will have to be reworked */ cpu_init_thread_core_maps(nthreads); /* Now that possible cpus are set, set nr_cpu_ids for later use */ setup_nr_cpu_ids(); free_unused_pacas(); } #endif /* CONFIG_SMP */ #ifdef CONFIG_PCSPKR_PLATFORM static __init int add_pcspkr(void) { struct device_node *np; struct platform_device *pd; int ret; np = of_find_compatible_node(NULL, NULL, "pnpPNP,100"); of_node_put(np); if (!np) return -ENODEV; pd = platform_device_alloc("pcspkr", -1); if (!pd) return -ENOMEM; ret = platform_device_add(pd); if (ret) platform_device_put(pd); return ret; } device_initcall(add_pcspkr); #endif /* CONFIG_PCSPKR_PLATFORM */ void probe_machine(void) { extern struct machdep_calls __machine_desc_start; extern struct machdep_calls __machine_desc_end; unsigned int i; /* * Iterate all ppc_md structures until we find the proper * one for the current machine type */ DBG("Probing machine type ...\n"); /* * Check ppc_md is empty, if not we have a bug, ie, we setup an * entry before probe_machine() which will be overwritten */ for (i = 0; i < (sizeof(ppc_md) / sizeof(void *)); i++) { if (((void **)&ppc_md)[i]) { printk(KERN_ERR "Entry %d in ppc_md non empty before" " machine probe !\n", i); } } for (machine_id = &__machine_desc_start; machine_id < &__machine_desc_end; machine_id++) { DBG(" %s ...", machine_id->name); memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls)); if (ppc_md.probe()) { DBG(" match !\n"); break; } DBG("\n"); } /* What can we do if we didn't find ? */ if (machine_id >= &__machine_desc_end) { pr_err("No suitable machine description found !\n"); for (;;); } printk(KERN_INFO "Using %s machine description\n", ppc_md.name); } /* Match a class of boards, not a specific device configuration. */ int check_legacy_ioport(unsigned long base_port) { struct device_node *parent, *np = NULL; int ret = -ENODEV; switch(base_port) { case I8042_DATA_REG: if (!(np = of_find_compatible_node(NULL, NULL, "pnpPNP,303"))) np = of_find_compatible_node(NULL, NULL, "pnpPNP,f03"); if (np) { parent = of_get_parent(np); of_i8042_kbd_irq = irq_of_parse_and_map(parent, 0); if (!of_i8042_kbd_irq) of_i8042_kbd_irq = 1; of_i8042_aux_irq = irq_of_parse_and_map(parent, 1); if (!of_i8042_aux_irq) of_i8042_aux_irq = 12; of_node_put(np); np = parent; break; } np = of_find_node_by_type(NULL, "8042"); /* Pegasos has no device_type on its 8042 node, look for the * name instead */ if (!np) np = of_find_node_by_name(NULL, "8042"); if (np) { of_i8042_kbd_irq = 1; of_i8042_aux_irq = 12; } break; case FDC_BASE: /* FDC1 */ np = of_find_node_by_type(NULL, "fdc"); break; default: /* ipmi is supposed to fail here */ break; } if (!np) return ret; parent = of_get_parent(np); if (parent) { if (of_node_is_type(parent, "isa")) ret = 0; of_node_put(parent); } of_node_put(np); return ret; } EXPORT_SYMBOL(check_legacy_ioport); static int ppc_panic_event(struct notifier_block *this, unsigned long event, void *ptr) { /* * panic does a local_irq_disable, but we really * want interrupts to be hard disabled. */ hard_irq_disable(); /* * If firmware-assisted dump has been registered then trigger * firmware-assisted dump and let firmware handle everything else. */ crash_fadump(NULL, ptr); if (ppc_md.panic) ppc_md.panic(ptr); /* May not return */ return NOTIFY_DONE; } static struct notifier_block ppc_panic_block = { .notifier_call = ppc_panic_event, .priority = INT_MIN /* may not return; must be done last */ }; /* * Dump out kernel offset information on panic. */ static int dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p) { pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n", kaslr_offset(), KERNELBASE); return 0; } static struct notifier_block kernel_offset_notifier = { .notifier_call = dump_kernel_offset }; void __init setup_panic(void) { if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) atomic_notifier_chain_register(&panic_notifier_list, &kernel_offset_notifier); /* PPC64 always does a hard irq disable in its panic handler */ if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic) return; atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block); } #ifdef CONFIG_CHECK_CACHE_COHERENCY /* * For platforms that have configurable cache-coherency. This function * checks that the cache coherency setting of the kernel matches the setting * left by the firmware, as indicated in the device tree. Since a mismatch * will eventually result in DMA failures, we print * and error and call * BUG() in that case. */ #define KERNEL_COHERENCY (!IS_ENABLED(CONFIG_NOT_COHERENT_CACHE)) static int __init check_cache_coherency(void) { struct device_node *np; const void *prop; bool devtree_coherency; np = of_find_node_by_path("/"); prop = of_get_property(np, "coherency-off", NULL); of_node_put(np); devtree_coherency = prop ? false : true; if (devtree_coherency != KERNEL_COHERENCY) { printk(KERN_ERR "kernel coherency:%s != device tree_coherency:%s\n", KERNEL_COHERENCY ? "on" : "off", devtree_coherency ? "on" : "off"); BUG(); } return 0; } late_initcall(check_cache_coherency); #endif /* CONFIG_CHECK_CACHE_COHERENCY */ #ifdef CONFIG_DEBUG_FS struct dentry *powerpc_debugfs_root; EXPORT_SYMBOL(powerpc_debugfs_root); static int powerpc_debugfs_init(void) { powerpc_debugfs_root = debugfs_create_dir("powerpc", NULL); return 0; } arch_initcall(powerpc_debugfs_init); #endif void ppc_printk_progress(char *s, unsigned short hex) { pr_info("%s\n", s); } static __init void print_system_info(void) { pr_info("-----------------------------------------------------\n"); pr_info("phys_mem_size = 0x%llx\n", (unsigned long long)memblock_phys_mem_size()); pr_info("dcache_bsize = 0x%x\n", dcache_bsize); pr_info("icache_bsize = 0x%x\n", icache_bsize); if (ucache_bsize != 0) pr_info("ucache_bsize = 0x%x\n", ucache_bsize); pr_info("cpu_features = 0x%016lx\n", cur_cpu_spec->cpu_features); pr_info(" possible = 0x%016lx\n", (unsigned long)CPU_FTRS_POSSIBLE); pr_info(" always = 0x%016lx\n", (unsigned long)CPU_FTRS_ALWAYS); pr_info("cpu_user_features = 0x%08x 0x%08x\n", cur_cpu_spec->cpu_user_features, cur_cpu_spec->cpu_user_features2); pr_info("mmu_features = 0x%08x\n", cur_cpu_spec->mmu_features); #ifdef CONFIG_PPC64 pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features); #ifdef CONFIG_PPC_BOOK3S pr_info("vmalloc start = 0x%lx\n", KERN_VIRT_START); pr_info("IO start = 0x%lx\n", KERN_IO_START); pr_info("vmemmap start = 0x%lx\n", (unsigned long)vmemmap); #endif #endif if (!early_radix_enabled()) print_system_hash_info(); if (PHYSICAL_START > 0) pr_info("physical_start = 0x%llx\n", (unsigned long long)PHYSICAL_START); pr_info("-----------------------------------------------------\n"); } #ifdef CONFIG_SMP static void smp_setup_pacas(void) { int cpu; for_each_possible_cpu(cpu) { if (cpu == smp_processor_id()) continue; allocate_paca(cpu); set_hard_smp_processor_id(cpu, cpu_to_phys_id[cpu]); } memblock_free(__pa(cpu_to_phys_id), nr_cpu_ids * sizeof(u32)); cpu_to_phys_id = NULL; } #endif /* * Called into from start_kernel this initializes memblock, which is used * to manage page allocation until mem_init is called. */ void __init setup_arch(char **cmdline_p) { kasan_init(); *cmdline_p = boot_command_line; /* Set a half-reasonable default so udelay does something sensible */ loops_per_jiffy = 500000000 / HZ; /* Unflatten the device-tree passed by prom_init or kexec */ unflatten_device_tree(); /* * Initialize cache line/block info from device-tree (on ppc64) or * just cputable (on ppc32). */ initialize_cache_info(); /* Initialize RTAS if available. */ rtas_initialize(); /* Check if we have an initrd provided via the device-tree. */ check_for_initrd(); /* Probe the machine type, establish ppc_md. */ probe_machine(); /* Setup panic notifier if requested by the platform. */ setup_panic(); /* * Configure ppc_md.power_save (ppc32 only, 64-bit machines do * it from their respective probe() function. */ setup_power_save(); /* Discover standard serial ports. */ find_legacy_serial_ports(); /* Register early console with the printk subsystem. */ register_early_udbg_console(); /* Setup the various CPU maps based on the device-tree. */ smp_setup_cpu_maps(); /* Initialize xmon. */ xmon_setup(); /* Check the SMT related command line arguments (ppc64). */ check_smt_enabled(); /* Parse memory topology */ mem_topology_setup(); /* Set max_mapnr before paging_init() */ set_max_mapnr(max_pfn); /* * Release secondary cpus out of their spinloops at 0x60 now that * we can map physical -> logical CPU ids. * * Freescale Book3e parts spin in a loop provided by firmware, * so smp_release_cpus() does nothing for them. */ #ifdef CONFIG_SMP smp_setup_pacas(); /* On BookE, setup per-core TLB data structures. */ setup_tlb_core_data(); #endif /* Print various info about the machine that has been gathered so far. */ print_system_info(); /* Reserve large chunks of memory for use by CMA for KVM. */ kvm_cma_reserve(); /* Reserve large chunks of memory for us by CMA for hugetlb */ gigantic_hugetlb_cma_reserve(); klp_init_thread_info(&init_task); init_mm.start_code = (unsigned long)_stext; init_mm.end_code = (unsigned long) _etext; init_mm.end_data = (unsigned long) _edata; init_mm.brk = klimit; mm_iommu_init(&init_mm); irqstack_early_init(); exc_lvl_early_init(); emergency_stack_init(); smp_release_cpus(); initmem_init(); early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT); if (ppc_md.setup_arch) ppc_md.setup_arch(); setup_barrier_nospec(); setup_spectre_v2(); paging_init(); /* Initialize the MMU context management stuff. */ mmu_context_init(); /* Interrupt code needs to be 64K-aligned. */ if (IS_ENABLED(CONFIG_PPC64) && (unsigned long)_stext & 0xffff) panic("Kernelbase not 64K-aligned (0x%lx)!\n", (unsigned long)_stext); }