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Diffstat (limited to 'arch/powerpc/kernel/setup_64.c')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 801 |
1 files changed, 801 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c new file mode 100644 index 000000000..c69671c03 --- /dev/null +++ b/arch/powerpc/kernel/setup_64.c @@ -0,0 +1,801 @@ +/* + * + * Common boot and setup code. + * + * Copyright (C) 2001 PPC64 Team, IBM Corp + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#define DEBUG + +#include <linux/export.h> +#include <linux/string.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/reboot.h> +#include <linux/delay.h> +#include <linux/initrd.h> +#include <linux/seq_file.h> +#include <linux/ioport.h> +#include <linux/console.h> +#include <linux/utsname.h> +#include <linux/tty.h> +#include <linux/root_dev.h> +#include <linux/notifier.h> +#include <linux/cpu.h> +#include <linux/unistd.h> +#include <linux/serial.h> +#include <linux/serial_8250.h> +#include <linux/bootmem.h> +#include <linux/pci.h> +#include <linux/lockdep.h> +#include <linux/memblock.h> +#include <linux/hugetlb.h> +#include <linux/memory.h> +#include <linux/nmi.h> + +#include <asm/io.h> +#include <asm/kdump.h> +#include <asm/prom.h> +#include <asm/processor.h> +#include <asm/pgtable.h> +#include <asm/smp.h> +#include <asm/elf.h> +#include <asm/machdep.h> +#include <asm/paca.h> +#include <asm/time.h> +#include <asm/cputable.h> +#include <asm/sections.h> +#include <asm/btext.h> +#include <asm/nvram.h> +#include <asm/setup.h> +#include <asm/rtas.h> +#include <asm/iommu.h> +#include <asm/serial.h> +#include <asm/cache.h> +#include <asm/page.h> +#include <asm/mmu.h> +#include <asm/firmware.h> +#include <asm/xmon.h> +#include <asm/udbg.h> +#include <asm/kexec.h> +#include <asm/mmu_context.h> +#include <asm/code-patching.h> +#include <asm/kvm_ppc.h> +#include <asm/hugetlb.h> +#include <asm/epapr_hcalls.h> + +#ifdef DEBUG +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + +int spinning_secondaries; +u64 ppc64_pft_size; + +/* Pick defaults since we might want to patch instructions + * before we've read this from the device tree. + */ +struct ppc64_caches ppc64_caches = { + .dline_size = 0x40, + .log_dline_size = 6, + .iline_size = 0x40, + .log_iline_size = 6 +}; +EXPORT_SYMBOL_GPL(ppc64_caches); + +/* + * 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; + +#if defined(CONFIG_PPC_BOOK3E) && defined(CONFIG_SMP) +static void setup_tlb_core_data(void) +{ + int cpu; + + BUILD_BUG_ON(offsetof(struct tlb_core_data, lock) != 0); + + for_each_possible_cpu(cpu) { + int first = cpu_first_thread_sibling(cpu); + + paca[cpu].tcd_ptr = &paca[first].tcd; + + /* + * If we have threads, we need either tlbsrx. + * or e6500 tablewalk mode, or else TLB handlers + * will be racy and could produce duplicate entries. + */ + if (smt_enabled_at_boot >= 2 && + !mmu_has_feature(MMU_FTR_USE_TLBRSRV) && + book3e_htw_mode != PPC_HTW_E6500) { + /* Should we panic instead? */ + WARN_ONCE("%s: unsupported MMU configuration -- expect problems\n", + __func__); + } + } +} +#else +static void setup_tlb_core_data(void) +{ +} +#endif + +#ifdef CONFIG_SMP + +static char *smt_enabled_cmdline; + +/* Look for ibm,smt-enabled OF option */ +static void check_smt_enabled(void) +{ + struct device_node *dn; + const char *smt_option; + + /* Default to enabling all threads */ + smt_enabled_at_boot = threads_per_core; + + /* Allow the command line to overrule the OF option */ + if (smt_enabled_cmdline) { + if (!strcmp(smt_enabled_cmdline, "on")) + smt_enabled_at_boot = threads_per_core; + else if (!strcmp(smt_enabled_cmdline, "off")) + smt_enabled_at_boot = 0; + else { + int smt; + int rc; + + rc = kstrtoint(smt_enabled_cmdline, 10, &smt); + if (!rc) + smt_enabled_at_boot = + min(threads_per_core, smt); + } + } else { + dn = of_find_node_by_path("/options"); + if (dn) { + smt_option = of_get_property(dn, "ibm,smt-enabled", + NULL); + + if (smt_option) { + if (!strcmp(smt_option, "on")) + smt_enabled_at_boot = threads_per_core; + else if (!strcmp(smt_option, "off")) + smt_enabled_at_boot = 0; + } + + of_node_put(dn); + } + } +} + +/* Look for smt-enabled= cmdline option */ +static int __init early_smt_enabled(char *p) +{ + smt_enabled_cmdline = p; + return 0; +} +early_param("smt-enabled", early_smt_enabled); + +#else +#define check_smt_enabled() +#endif /* CONFIG_SMP */ + +/** Fix up paca fields required for the boot cpu */ +static void fixup_boot_paca(void) +{ + /* The boot cpu is started */ + get_paca()->cpu_start = 1; + /* Allow percpu accesses to work until we setup percpu data */ + get_paca()->data_offset = 0; +} + +static void cpu_ready_for_interrupts(void) +{ + /* Set IR and DR in PACA MSR */ + get_paca()->kernel_msr = MSR_KERNEL; + + /* + * Enable AIL if supported, and we are in hypervisor mode. If we are + * not in hypervisor mode, we enable relocation-on interrupts later + * in pSeries_setup_arch() using the H_SET_MODE hcall. + */ + if (cpu_has_feature(CPU_FTR_HVMODE) && + cpu_has_feature(CPU_FTR_ARCH_207S)) { + unsigned long lpcr = mfspr(SPRN_LPCR); + mtspr(SPRN_LPCR, lpcr | LPCR_AIL_3); + } +} + +/* + * Early initialization entry point. This is called by head.S + * with MMU translation disabled. We rely on the "feature" of + * the CPU that ignores the top 2 bits of the address in real + * mode so we can access kernel globals normally provided we + * only toy with things in the RMO region. From here, we do + * some early parsing of the device-tree to setup out MEMBLOCK + * data structures, and allocate & initialize the hash table + * and segment tables so we can start running with translation + * enabled. + * + * It is this function which will call the probe() callback of + * the various platform types and copy the matching one to the + * global ppc_md structure. Your platform can eventually do + * some very early initializations from the probe() routine, but + * this is not recommended, be very careful as, for example, the + * device-tree is not accessible via normal means at this point. + */ + +void __init early_setup(unsigned long dt_ptr) +{ + static __initdata struct paca_struct boot_paca; + + /* -------- printk is _NOT_ safe to use here ! ------- */ + + /* Identify CPU type */ + identify_cpu(0, mfspr(SPRN_PVR)); + + /* Assume we're on cpu 0 for now. Don't write to the paca yet! */ + initialise_paca(&boot_paca, 0); + setup_paca(&boot_paca); + fixup_boot_paca(); + + /* Initialize lockdep early or else spinlocks will blow */ + lockdep_init(); + + /* -------- printk is now safe to use ------- */ + + /* Enable early debugging if any specified (see udbg.h) */ + udbg_early_init(); + + DBG(" -> early_setup(), dt_ptr: 0x%lx\n", dt_ptr); + + /* + * Do early initialization using the flattened device + * tree, such as retrieving the physical memory map or + * calculating/retrieving the hash table size. + */ + early_init_devtree(__va(dt_ptr)); + + epapr_paravirt_early_init(); + + /* Now we know the logical id of our boot cpu, setup the paca. */ + setup_paca(&paca[boot_cpuid]); + fixup_boot_paca(); + + /* Probe the machine type */ + probe_machine(); + + setup_kdump_trampoline(); + + DBG("Found, Initializing memory management...\n"); + + /* Initialize the hash table or TLB handling */ + early_init_mmu(); + + /* + * At this point, we can let interrupts switch to virtual mode + * (the MMU has been setup), so adjust the MSR in the PACA to + * have IR and DR set and enable AIL if it exists + */ + cpu_ready_for_interrupts(); + + /* Reserve large chunks of memory for use by CMA for KVM */ + kvm_cma_reserve(); + + /* + * Reserve any gigantic pages requested on the command line. + * memblock needs to have been initialized by the time this is + * called since this will reserve memory. + */ + reserve_hugetlb_gpages(); + + DBG(" <- early_setup()\n"); + +#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX + /* + * This needs to be done *last* (after the above DBG() even) + * + * Right after we return from this function, we turn on the MMU + * which means the real-mode access trick that btext does will + * no longer work, it needs to switch to using a real MMU + * mapping. This call will ensure that it does + */ + btext_map(); +#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */ +} + +#ifdef CONFIG_SMP +void early_setup_secondary(void) +{ + /* Mark interrupts enabled in PACA */ + get_paca()->soft_enabled = 0; + + /* Initialize the hash table or TLB handling */ + early_init_mmu_secondary(); + + /* + * At this point, we can let interrupts switch to virtual mode + * (the MMU has been setup), so adjust the MSR in the PACA to + * have IR and DR set. + */ + cpu_ready_for_interrupts(); +} + +#endif /* CONFIG_SMP */ + +#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC) +void smp_release_cpus(void) +{ + unsigned long *ptr; + int i; + + DBG(" -> smp_release_cpus()\n"); + + /* All secondary cpus are spinning on a common spinloop, release them + * all now so they can start to spin on their individual paca + * spinloops. For non SMP kernels, the secondary cpus never get out + * of the common spinloop. + */ + + ptr = (unsigned long *)((unsigned long)&__secondary_hold_spinloop + - PHYSICAL_START); + *ptr = ppc_function_entry(generic_secondary_smp_init); + + /* And wait a bit for them to catch up */ + for (i = 0; i < 100000; i++) { + mb(); + HMT_low(); + if (spinning_secondaries == 0) + break; + udelay(1); + } + DBG("spinning_secondaries = %d\n", spinning_secondaries); + + DBG(" <- smp_release_cpus()\n"); +} +#endif /* CONFIG_SMP || CONFIG_KEXEC */ + +/* + * Initialize some remaining members of the ppc64_caches and systemcfg + * structures + * (at least until we get rid of them completely). This is mostly some + * cache informations about the CPU that will be used by cache flush + * routines and/or provided to userland + */ +static void __init initialize_cache_info(void) +{ + struct device_node *np; + unsigned long num_cpus = 0; + + DBG(" -> initialize_cache_info()\n"); + + for_each_node_by_type(np, "cpu") { + num_cpus += 1; + + /* + * We're assuming *all* of the CPUs have the same + * d-cache and i-cache sizes... -Peter + */ + if (num_cpus == 1) { + const __be32 *sizep, *lsizep; + u32 size, lsize; + + size = 0; + lsize = cur_cpu_spec->dcache_bsize; + sizep = of_get_property(np, "d-cache-size", NULL); + if (sizep != NULL) + size = be32_to_cpu(*sizep); + lsizep = of_get_property(np, "d-cache-block-size", + NULL); + /* fallback if block size missing */ + if (lsizep == NULL) + lsizep = of_get_property(np, + "d-cache-line-size", + NULL); + if (lsizep != NULL) + lsize = be32_to_cpu(*lsizep); + if (sizep == NULL || lsizep == NULL) + DBG("Argh, can't find dcache properties ! " + "sizep: %p, lsizep: %p\n", sizep, lsizep); + + ppc64_caches.dsize = size; + ppc64_caches.dline_size = lsize; + ppc64_caches.log_dline_size = __ilog2(lsize); + ppc64_caches.dlines_per_page = PAGE_SIZE / lsize; + + size = 0; + lsize = cur_cpu_spec->icache_bsize; + sizep = of_get_property(np, "i-cache-size", NULL); + if (sizep != NULL) + size = be32_to_cpu(*sizep); + lsizep = of_get_property(np, "i-cache-block-size", + NULL); + if (lsizep == NULL) + lsizep = of_get_property(np, + "i-cache-line-size", + NULL); + if (lsizep != NULL) + lsize = be32_to_cpu(*lsizep); + if (sizep == NULL || lsizep == NULL) + DBG("Argh, can't find icache properties ! " + "sizep: %p, lsizep: %p\n", sizep, lsizep); + + ppc64_caches.isize = size; + ppc64_caches.iline_size = lsize; + ppc64_caches.log_iline_size = __ilog2(lsize); + ppc64_caches.ilines_per_page = PAGE_SIZE / lsize; + } + } + + DBG(" <- initialize_cache_info()\n"); +} + + +/* + * Do some initial setup of the system. The parameters are those which + * were passed in from the bootloader. + */ +void __init setup_system(void) +{ + DBG(" -> setup_system()\n"); + + /* Apply the CPUs-specific and firmware specific fixups to kernel + * text (nop out sections not relevant to this CPU or this firmware) + */ + do_feature_fixups(cur_cpu_spec->cpu_features, + &__start___ftr_fixup, &__stop___ftr_fixup); + do_feature_fixups(cur_cpu_spec->mmu_features, + &__start___mmu_ftr_fixup, &__stop___mmu_ftr_fixup); + do_feature_fixups(powerpc_firmware_features, + &__start___fw_ftr_fixup, &__stop___fw_ftr_fixup); + do_lwsync_fixups(cur_cpu_spec->cpu_features, + &__start___lwsync_fixup, &__stop___lwsync_fixup); + do_final_fixups(); + + /* + * Unflatten the device-tree passed by prom_init or kexec + */ + unflatten_device_tree(); + + /* + * Fill the ppc64_caches & systemcfg structures with informations + * retrieved from the device-tree. + */ + initialize_cache_info(); + +#ifdef CONFIG_PPC_RTAS + /* + * Initialize RTAS if available + */ + rtas_initialize(); +#endif /* CONFIG_PPC_RTAS */ + + /* + * Check if we have an initrd provided via the device-tree + */ + check_for_initrd(); + + /* + * Do some platform specific early initializations, that includes + * setting up the hash table pointers. It also sets up some interrupt-mapping + * related options that will be used by finish_device_tree() + */ + if (ppc_md.init_early) + ppc_md.init_early(); + + /* + * We can discover serial ports now since the above did setup the + * hash table management for us, thus ioremap works. We do that early + * so that further code can be debugged + */ + find_legacy_serial_ports(); + + /* + * Register early console + */ + register_early_udbg_console(); + + /* + * Initialize xmon + */ + xmon_setup(); + + smp_setup_cpu_maps(); + check_smt_enabled(); + setup_tlb_core_data(); + + /* + * Freescale Book3e parts spin in a loop provided by firmware, + * so smp_release_cpus() does nothing for them + */ +#if defined(CONFIG_SMP) && !defined(CONFIG_PPC_FSL_BOOK3E) + /* Release secondary cpus out of their spinloops at 0x60 now that + * we can map physical -> logical CPU ids + */ + smp_release_cpus(); +#endif + + pr_info("Starting Linux PPC64 %s\n", init_utsname()->version); + + pr_info("-----------------------------------------------------\n"); + pr_info("ppc64_pft_size = 0x%llx\n", ppc64_pft_size); + pr_info("phys_mem_size = 0x%llx\n", memblock_phys_mem_size()); + + if (ppc64_caches.dline_size != 0x80) + pr_info("dcache_line_size = 0x%x\n", ppc64_caches.dline_size); + if (ppc64_caches.iline_size != 0x80) + pr_info("icache_line_size = 0x%x\n", ppc64_caches.iline_size); + + pr_info("cpu_features = 0x%016lx\n", cur_cpu_spec->cpu_features); + pr_info(" possible = 0x%016lx\n", CPU_FTRS_POSSIBLE); + pr_info(" always = 0x%016lx\n", 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); + pr_info("firmware_features = 0x%016lx\n", powerpc_firmware_features); + +#ifdef CONFIG_PPC_STD_MMU_64 + if (htab_address) + pr_info("htab_address = 0x%p\n", htab_address); + + pr_info("htab_hash_mask = 0x%lx\n", htab_hash_mask); +#endif + + if (PHYSICAL_START > 0) + pr_info("physical_start = 0x%llx\n", + (unsigned long long)PHYSICAL_START); + pr_info("-----------------------------------------------------\n"); + + DBG(" <- setup_system()\n"); +} + +/* This returns the limit below which memory accesses to the linear + * mapping are guarnateed not to cause a TLB or SLB miss. This is + * used to allocate interrupt or emergency stacks for which our + * exception entry path doesn't deal with being interrupted. + */ +static u64 safe_stack_limit(void) +{ +#ifdef CONFIG_PPC_BOOK3E + /* Freescale BookE bolts the entire linear mapping */ + if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) + return linear_map_top; + /* Other BookE, we assume the first GB is bolted */ + return 1ul << 30; +#else + /* BookS, the first segment is bolted */ + if (mmu_has_feature(MMU_FTR_1T_SEGMENT)) + return 1UL << SID_SHIFT_1T; + return 1UL << SID_SHIFT; +#endif +} + +static void __init irqstack_early_init(void) +{ + u64 limit = safe_stack_limit(); + unsigned int i; + + /* + * Interrupt stacks must be in the first segment since we + * cannot afford to take SLB misses on them. + */ + for_each_possible_cpu(i) { + softirq_ctx[i] = (struct thread_info *) + __va(memblock_alloc_base(THREAD_SIZE, + THREAD_SIZE, limit)); + hardirq_ctx[i] = (struct thread_info *) + __va(memblock_alloc_base(THREAD_SIZE, + THREAD_SIZE, limit)); + } +} + +#ifdef CONFIG_PPC_BOOK3E +static void __init exc_lvl_early_init(void) +{ + unsigned int i; + unsigned long sp; + + for_each_possible_cpu(i) { + sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE); + critirq_ctx[i] = (struct thread_info *)__va(sp); + paca[i].crit_kstack = __va(sp + THREAD_SIZE); + + sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE); + dbgirq_ctx[i] = (struct thread_info *)__va(sp); + paca[i].dbg_kstack = __va(sp + THREAD_SIZE); + + sp = memblock_alloc(THREAD_SIZE, THREAD_SIZE); + mcheckirq_ctx[i] = (struct thread_info *)__va(sp); + paca[i].mc_kstack = __va(sp + THREAD_SIZE); + } + + if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC)) + patch_exception(0x040, exc_debug_debug_book3e); +} +#else +#define exc_lvl_early_init() +#endif + +/* + * Stack space used when we detect a bad kernel stack pointer, and + * early in SMP boots before relocation is enabled. Exclusive emergency + * stack for machine checks. + */ +static void __init emergency_stack_init(void) +{ + u64 limit; + unsigned int i; + + /* + * Emergency stacks must be under 256MB, we cannot afford to take + * SLB misses on them. The ABI also requires them to be 128-byte + * aligned. + * + * Since we use these as temporary stacks during secondary CPU + * bringup, we need to get at them in real mode. This means they + * must also be within the RMO region. + */ + limit = min(safe_stack_limit(), ppc64_rma_size); + + for_each_possible_cpu(i) { + unsigned long sp; + sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit); + sp += THREAD_SIZE; + paca[i].emergency_sp = __va(sp); + +#ifdef CONFIG_PPC_BOOK3S_64 + /* emergency stack for machine check exception handling. */ + sp = memblock_alloc_base(THREAD_SIZE, THREAD_SIZE, limit); + sp += THREAD_SIZE; + paca[i].mc_emergency_sp = __va(sp); +#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) +{ + *cmdline_p = boot_command_line; + + /* + * Set cache line size based on type of cpu as a default. + * Systems with OF can look in the properties on the cpu node(s) + * for a possibly more accurate value. + */ + dcache_bsize = ppc64_caches.dline_size; + icache_bsize = ppc64_caches.iline_size; + + if (ppc_md.panic) + setup_panic(); + + 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; +#ifdef CONFIG_PPC_64K_PAGES + init_mm.context.pte_frag = NULL; +#endif + irqstack_early_init(); + exc_lvl_early_init(); + emergency_stack_init(); + + initmem_init(); + +#ifdef CONFIG_DUMMY_CONSOLE + conswitchp = &dummy_con; +#endif + + if (ppc_md.setup_arch) + ppc_md.setup_arch(); + + paging_init(); + + /* Initialize the MMU context management stuff */ + mmu_context_init(); + + /* Interrupt code needs to be 64K-aligned */ + if ((unsigned long)_stext & 0xffff) + panic("Kernelbase not 64K-aligned (0x%lx)!\n", + (unsigned long)_stext); +} + +#ifdef CONFIG_SMP +#define PCPU_DYN_SIZE () + +static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align) +{ + return __alloc_bootmem_node(NODE_DATA(cpu_to_node(cpu)), size, align, + __pa(MAX_DMA_ADDRESS)); +} + +static void __init pcpu_fc_free(void *ptr, size_t size) +{ + free_bootmem(__pa(ptr), size); +} + +static int pcpu_cpu_distance(unsigned int from, unsigned int to) +{ + if (cpu_to_node(from) == cpu_to_node(to)) + return LOCAL_DISTANCE; + else + return REMOTE_DISTANCE; +} + +unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; +EXPORT_SYMBOL(__per_cpu_offset); + +void __init setup_per_cpu_areas(void) +{ + const size_t dyn_size = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE; + size_t atom_size; + unsigned long delta; + unsigned int cpu; + int rc; + + /* + * Linear mapping is one of 4K, 1M and 16M. For 4K, no need + * to group units. For larger mappings, use 1M atom which + * should be large enough to contain a number of units. + */ + if (mmu_linear_psize == MMU_PAGE_4K) + atom_size = PAGE_SIZE; + else + atom_size = 1 << 20; + + rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance, + pcpu_fc_alloc, pcpu_fc_free); + if (rc < 0) + panic("cannot initialize percpu area (err=%d)", rc); + + delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; + for_each_possible_cpu(cpu) { + __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; + paca[cpu].data_offset = __per_cpu_offset[cpu]; + } +} +#endif + +#ifdef CONFIG_MEMORY_HOTPLUG_SPARSE +unsigned long memory_block_size_bytes(void) +{ + if (ppc_md.memory_block_size) + return ppc_md.memory_block_size(); + + return MIN_MEMORY_BLOCK_SIZE; +} +#endif + +#if defined(CONFIG_PPC_INDIRECT_PIO) || defined(CONFIG_PPC_INDIRECT_MMIO) +struct ppc_pci_io ppc_pci_io; +EXPORT_SYMBOL(ppc_pci_io); +#endif + +#ifdef CONFIG_HARDLOCKUP_DETECTOR +u64 hw_nmi_get_sample_period(int watchdog_thresh) +{ + return ppc_proc_freq * watchdog_thresh; +} + +/* + * The hardlockup detector breaks PMU event based branches and is likely + * to get false positives in KVM guests, so disable it by default. + */ +static int __init disable_hardlockup_detector(void) +{ + hardlockup_detector_disable(); + + return 0; +} +early_initcall(disable_hardlockup_detector); +#endif |