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Diffstat (limited to 'arch/powerpc/kernel/setup_64.c')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 932 |
1 files changed, 932 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..246201d0d --- /dev/null +++ b/arch/powerpc/kernel/setup_64.c @@ -0,0 +1,932 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * + * Common boot and setup code. + * + * Copyright (C) 2001 PPC64 Team, IBM Corp + */ + +#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/memblock.h> +#include <linux/pci.h> +#include <linux/lockdep.h> +#include <linux/memory.h> +#include <linux/nmi.h> +#include <linux/pgtable.h> +#include <linux/of.h> +#include <linux/of_fdt.h> + +#include <asm/asm-prototypes.h> +#include <asm/kvm_guest.h> +#include <asm/io.h> +#include <asm/kdump.h> +#include <asm/processor.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/dt_cpu_ftrs.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/code-patching.h> +#include <asm/ftrace.h> +#include <asm/opal.h> +#include <asm/cputhreads.h> +#include <asm/hw_irq.h> +#include <asm/feature-fixups.h> +#include <asm/kup.h> +#include <asm/early_ioremap.h> +#include <asm/pgalloc.h> + +#include "setup.h" + +int spinning_secondaries; +u64 ppc64_pft_size; + +struct ppc64_caches ppc64_caches = { + .l1d = { + .block_size = 0x40, + .log_block_size = 6, + }, + .l1i = { + .block_size = 0x40, + .log_block_size = 6 + }, +}; +EXPORT_SYMBOL_GPL(ppc64_caches); + +#if defined(CONFIG_PPC_BOOK3E_64) && defined(CONFIG_SMP) +void __init 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); + + /* + * If we boot via kdump on a non-primary thread, + * make sure we point at the thread that actually + * set up this TLB. + */ + if (cpu_first_thread_sibling(boot_cpuid) == first) + first = boot_cpuid; + + paca_ptrs[cpu]->tcd_ptr = &paca_ptrs[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. + * Should we panic instead? + */ + WARN_ONCE(smt_enabled_at_boot >= 2 && + book3e_htw_mode != PPC_HTW_E6500, + "%s: unsupported MMU configuration\n", __func__); + } +} +#endif + +#ifdef CONFIG_SMP + +static char *smt_enabled_cmdline; + +/* Look for ibm,smt-enabled OF option */ +void __init 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); + +#endif /* CONFIG_SMP */ + +/** Fix up paca fields required for the boot cpu */ +static void __init fixup_boot_paca(struct paca_struct *boot_paca) +{ + /* The boot cpu is started */ + boot_paca->cpu_start = 1; +#ifdef CONFIG_PPC_BOOK3S_64 + /* + * Give the early boot machine check stack somewhere to use, use + * half of the init stack. This is a bit hacky but there should not be + * deep stack usage in early init so shouldn't overflow it or overwrite + * things. + */ + boot_paca->mc_emergency_sp = (void *)&init_thread_union + + (THREAD_SIZE/2); +#endif + /* Allow percpu accesses to work until we setup percpu data */ + boot_paca->data_offset = 0; + /* Mark interrupts soft and hard disabled in PACA */ + boot_paca->irq_soft_mask = IRQS_DISABLED; + boot_paca->irq_happened = PACA_IRQ_HARD_DIS; + WARN_ON(mfmsr() & MSR_EE); +} + +static void __init configure_exceptions(void) +{ + /* + * Setup the trampolines from the lowmem exception vectors + * to the kdump kernel when not using a relocatable kernel. + */ + setup_kdump_trampoline(); + + /* Under a PAPR hypervisor, we need hypercalls */ + if (firmware_has_feature(FW_FEATURE_SET_MODE)) { + /* + * - PR KVM does not support AIL mode interrupts in the host + * while a PR guest is running. + * + * - SCV system call interrupt vectors are only implemented for + * AIL mode interrupts. + * + * - On pseries, AIL mode can only be enabled and disabled + * system-wide so when a PR VM is created on a pseries host, + * all CPUs of the host are set to AIL=0 mode. + * + * - Therefore host CPUs must not execute scv while a PR VM + * exists. + * + * - SCV support can not be disabled dynamically because the + * feature is advertised to host userspace. Disabling the + * facility and emulating it would be possible but is not + * implemented. + * + * - So SCV support is blanket disabled if PR KVM could possibly + * run. That is, PR support compiled in, booting on pseries + * with hash MMU. + */ + if (IS_ENABLED(CONFIG_KVM_BOOK3S_PR_POSSIBLE) && !radix_enabled()) { + init_task.thread.fscr &= ~FSCR_SCV; + cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_SCV; + } + + /* Enable AIL if possible */ + if (!pseries_enable_reloc_on_exc()) { + init_task.thread.fscr &= ~FSCR_SCV; + cur_cpu_spec->cpu_user_features2 &= ~PPC_FEATURE2_SCV; + } + + /* + * Tell the hypervisor that we want our exceptions to + * be taken in little endian mode. + * + * We don't call this for big endian as our calling convention + * makes us always enter in BE, and the call may fail under + * some circumstances with kdump. + */ +#ifdef __LITTLE_ENDIAN__ + pseries_little_endian_exceptions(); +#endif + } else { + /* Set endian mode using OPAL */ + if (firmware_has_feature(FW_FEATURE_OPAL)) + opal_configure_cores(); + + /* AIL on native is done in cpu_ready_for_interrupts() */ + } +} + +static void cpu_ready_for_interrupts(void) +{ + /* + * Enable AIL if supported, and we are in hypervisor mode. This + * is called once for every processor. + * + * If we are not in hypervisor mode the job is done once for + * the whole partition in configure_exceptions(). + */ + if (cpu_has_feature(CPU_FTR_HVMODE)) { + unsigned long lpcr = mfspr(SPRN_LPCR); + unsigned long new_lpcr = lpcr; + + if (cpu_has_feature(CPU_FTR_ARCH_31)) { + /* P10 DD1 does not have HAIL */ + if (pvr_version_is(PVR_POWER10) && + (mfspr(SPRN_PVR) & 0xf00) == 0x100) + new_lpcr |= LPCR_AIL_3; + else + new_lpcr |= LPCR_HAIL; + } else if (cpu_has_feature(CPU_FTR_ARCH_207S)) { + new_lpcr |= LPCR_AIL_3; + } + + if (new_lpcr != lpcr) + mtspr(SPRN_LPCR, new_lpcr); + } + + /* + * Set HFSCR:TM based on CPU features: + * In the special case of TM no suspend (P9N DD2.1), Linux is + * told TM is off via the dt-ftrs but told to (partially) use + * it via OPAL_REINIT_CPUS_TM_SUSPEND_DISABLED. So HFSCR[TM] + * will be off from dt-ftrs but we need to turn it on for the + * no suspend case. + */ + if (cpu_has_feature(CPU_FTR_HVMODE)) { + if (cpu_has_feature(CPU_FTR_TM_COMP)) + mtspr(SPRN_HFSCR, mfspr(SPRN_HFSCR) | HFSCR_TM); + else + mtspr(SPRN_HFSCR, mfspr(SPRN_HFSCR) & ~HFSCR_TM); + } + + /* Set IR and DR in PACA MSR */ + get_paca()->kernel_msr = MSR_KERNEL; +} + +unsigned long spr_default_dscr = 0; + +static void __init record_spr_defaults(void) +{ + if (early_cpu_has_feature(CPU_FTR_DSCR)) + spr_default_dscr = mfspr(SPRN_DSCR); +} + +/* + * 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 ! ------- */ + + /* + * Assume we're on cpu 0 for now. + * + * We need to load a PACA very early for a few reasons. + * + * The stack protector canary is stored in the paca, so as soon as we + * call any stack protected code we need r13 pointing somewhere valid. + * + * If we are using kcov it will call in_task() in its instrumentation, + * which relies on the current task from the PACA. + * + * dt_cpu_ftrs_init() calls into generic OF/fdt code, as well as + * printk(), which can trigger both stack protector and kcov. + * + * percpu variables and spin locks also use the paca. + * + * So set up a temporary paca. It will be replaced below once we know + * what CPU we are on. + */ + initialise_paca(&boot_paca, 0); + fixup_boot_paca(&boot_paca); + WARN_ON(local_paca != 0); + setup_paca(&boot_paca); /* install the paca into registers */ + + /* -------- printk is now safe to use ------- */ + + if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) && (mfmsr() & MSR_HV)) + enable_machine_check(); + + /* Try new device tree based feature discovery ... */ + if (!dt_cpu_ftrs_init(__va(dt_ptr))) + /* Otherwise use the old style CPU table */ + identify_cpu(0, mfspr(SPRN_PVR)); + + /* Enable early debugging if any specified (see udbg.h) */ + udbg_early_init(); + + udbg_printf(" -> %s(), dt_ptr: 0x%lx\n", __func__, dt_ptr); + + /* + * Do early initialization using the flattened device + * tree, such as retrieving the physical memory map or + * calculating/retrieving the hash table size, discover + * boot_cpuid and boot_cpu_hwid. + */ + early_init_devtree(__va(dt_ptr)); + + allocate_paca_ptrs(); + allocate_paca(boot_cpuid); + set_hard_smp_processor_id(boot_cpuid, boot_cpu_hwid); + fixup_boot_paca(paca_ptrs[boot_cpuid]); + setup_paca(paca_ptrs[boot_cpuid]); /* install the paca into registers */ + // smp_processor_id() now reports boot_cpuid + +#ifdef CONFIG_SMP + task_thread_info(current)->cpu = boot_cpuid; // fix task_cpu(current) +#endif + + /* + * Configure exception handlers. This include setting up trampolines + * if needed, setting exception endian mode, etc... + */ + configure_exceptions(); + + /* + * Configure Kernel Userspace Protection. This needs to happen before + * feature fixups for platforms that implement this using features. + */ + setup_kup(); + + /* Apply all the dynamic patching */ + apply_feature_fixups(); + setup_feature_keys(); + + /* Initialize the hash table or TLB handling */ + early_init_mmu(); + + early_ioremap_setup(); + + /* + * After firmware and early platform setup code has set things up, + * we note the SPR values for configurable control/performance + * registers, and use those as initial defaults. + */ + record_spr_defaults(); + + /* + * 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(); + + /* + * We enable ftrace here, but since we only support DYNAMIC_FTRACE, it + * will only actually get enabled on the boot cpu much later once + * ftrace itself has been initialized. + */ + this_cpu_enable_ftrace(); + + udbg_printf(" <- %s()\n", __func__); + +#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX + /* + * This needs to be done *last* (after the above udbg_printf() 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 disabled in PACA */ + irq_soft_mask_set(IRQS_DISABLED); + + /* Initialize the hash table or TLB handling */ + early_init_mmu_secondary(); + + /* Perform any KUP setup that is per-cpu */ + setup_kup(); + + /* + * 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 */ + +void __noreturn panic_smp_self_stop(void) +{ + hard_irq_disable(); + spin_begin(); + while (1) + spin_cpu_relax(); +} + +#if defined(CONFIG_SMP) || defined(CONFIG_KEXEC_CORE) +static bool use_spinloop(void) +{ + if (IS_ENABLED(CONFIG_PPC_BOOK3S)) { + /* + * See comments in head_64.S -- not all platforms insert + * secondaries at __secondary_hold and wait at the spin + * loop. + */ + if (firmware_has_feature(FW_FEATURE_OPAL)) + return false; + return true; + } + + /* + * When book3e boots from kexec, the ePAPR spin table does + * not get used. + */ + return of_property_read_bool(of_chosen, "linux,booted-from-kexec"); +} + +void smp_release_cpus(void) +{ + unsigned long *ptr; + int i; + + if (!use_spinloop()) + return; + + /* 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); + } + pr_debug("spinning_secondaries = %d\n", spinning_secondaries); +} +#endif /* CONFIG_SMP || CONFIG_KEXEC_CORE */ + +/* + * 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 init_cache_info(struct ppc_cache_info *info, u32 size, u32 lsize, + u32 bsize, u32 sets) +{ + info->size = size; + info->sets = sets; + info->line_size = lsize; + info->block_size = bsize; + info->log_block_size = __ilog2(bsize); + if (bsize) + info->blocks_per_page = PAGE_SIZE / bsize; + else + info->blocks_per_page = 0; + + if (sets == 0) + info->assoc = 0xffff; + else + info->assoc = size / (sets * lsize); +} + +static bool __init parse_cache_info(struct device_node *np, + bool icache, + struct ppc_cache_info *info) +{ + static const char *ipropnames[] __initdata = { + "i-cache-size", + "i-cache-sets", + "i-cache-block-size", + "i-cache-line-size", + }; + static const char *dpropnames[] __initdata = { + "d-cache-size", + "d-cache-sets", + "d-cache-block-size", + "d-cache-line-size", + }; + const char **propnames = icache ? ipropnames : dpropnames; + const __be32 *sizep, *lsizep, *bsizep, *setsp; + u32 size, lsize, bsize, sets; + bool success = true; + + size = 0; + sets = -1u; + lsize = bsize = cur_cpu_spec->dcache_bsize; + sizep = of_get_property(np, propnames[0], NULL); + if (sizep != NULL) + size = be32_to_cpu(*sizep); + setsp = of_get_property(np, propnames[1], NULL); + if (setsp != NULL) + sets = be32_to_cpu(*setsp); + bsizep = of_get_property(np, propnames[2], NULL); + lsizep = of_get_property(np, propnames[3], NULL); + if (bsizep == NULL) + bsizep = lsizep; + if (lsizep == NULL) + lsizep = bsizep; + if (lsizep != NULL) + lsize = be32_to_cpu(*lsizep); + if (bsizep != NULL) + bsize = be32_to_cpu(*bsizep); + if (sizep == NULL || bsizep == NULL || lsizep == NULL) + success = false; + + /* + * OF is weird .. it represents fully associative caches + * as "1 way" which doesn't make much sense and doesn't + * leave room for direct mapped. We'll assume that 0 + * in OF means direct mapped for that reason. + */ + if (sets == 1) + sets = 0; + else if (sets == 0) + sets = 1; + + init_cache_info(info, size, lsize, bsize, sets); + + return success; +} + +void __init initialize_cache_info(void) +{ + struct device_node *cpu = NULL, *l2, *l3 = NULL; + u32 pvr; + + /* + * All shipping POWER8 machines have a firmware bug that + * puts incorrect information in the device-tree. This will + * be (hopefully) fixed for future chips but for now hard + * code the values if we are running on one of these + */ + pvr = PVR_VER(mfspr(SPRN_PVR)); + if (pvr == PVR_POWER8 || pvr == PVR_POWER8E || + pvr == PVR_POWER8NVL) { + /* size lsize blk sets */ + init_cache_info(&ppc64_caches.l1i, 0x8000, 128, 128, 32); + init_cache_info(&ppc64_caches.l1d, 0x10000, 128, 128, 64); + init_cache_info(&ppc64_caches.l2, 0x80000, 128, 0, 512); + init_cache_info(&ppc64_caches.l3, 0x800000, 128, 0, 8192); + } else + cpu = of_find_node_by_type(NULL, "cpu"); + + /* + * We're assuming *all* of the CPUs have the same + * d-cache and i-cache sizes... -Peter + */ + if (cpu) { + if (!parse_cache_info(cpu, false, &ppc64_caches.l1d)) + pr_warn("Argh, can't find dcache properties !\n"); + + if (!parse_cache_info(cpu, true, &ppc64_caches.l1i)) + pr_warn("Argh, can't find icache properties !\n"); + + /* + * Try to find the L2 and L3 if any. Assume they are + * unified and use the D-side properties. + */ + l2 = of_find_next_cache_node(cpu); + of_node_put(cpu); + if (l2) { + parse_cache_info(l2, false, &ppc64_caches.l2); + l3 = of_find_next_cache_node(l2); + of_node_put(l2); + } + if (l3) { + parse_cache_info(l3, false, &ppc64_caches.l3); + of_node_put(l3); + } + } + + /* For use by binfmt_elf */ + dcache_bsize = ppc64_caches.l1d.block_size; + icache_bsize = ppc64_caches.l1i.block_size; + + cur_cpu_spec->dcache_bsize = dcache_bsize; + cur_cpu_spec->icache_bsize = icache_bsize; +} + +/* + * This returns the limit below which memory accesses to the linear + * mapping are guarnateed not to cause an architectural exception (e.g., + * TLB or SLB miss fault). + * + * This is used to allocate PACAs and various interrupt stacks that + * that are accessed early in interrupt handlers that must not cause + * re-entrant interrupts. + */ +__init u64 ppc64_bolted_size(void) +{ +#ifdef CONFIG_PPC_BOOK3E_64 + /* Freescale BookE bolts the entire linear mapping */ + /* XXX: BookE ppc64_rma_limit setup seems to disagree? */ + if (early_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 radix, does not take faults on linear mapping */ + if (early_radix_enabled()) + return ULONG_MAX; + + /* BookS hash, the first segment is bolted */ + if (early_mmu_has_feature(MMU_FTR_1T_SEGMENT)) + return 1UL << SID_SHIFT_1T; + return 1UL << SID_SHIFT; +#endif +} + +static void *__init alloc_stack(unsigned long limit, int cpu) +{ + void *ptr; + + BUILD_BUG_ON(STACK_INT_FRAME_SIZE % 16); + + ptr = memblock_alloc_try_nid(THREAD_SIZE, THREAD_ALIGN, + MEMBLOCK_LOW_LIMIT, limit, + early_cpu_to_node(cpu)); + if (!ptr) + panic("cannot allocate stacks"); + + return ptr; +} + +void __init irqstack_early_init(void) +{ + u64 limit = ppc64_bolted_size(); + unsigned int i; + + /* + * Interrupt stacks must be in the first segment since we + * cannot afford to take SLB misses on them. They are not + * accessed in realmode. + */ + for_each_possible_cpu(i) { + softirq_ctx[i] = alloc_stack(limit, i); + hardirq_ctx[i] = alloc_stack(limit, i); + } +} + +#ifdef CONFIG_PPC_BOOK3E_64 +void __init exc_lvl_early_init(void) +{ + unsigned int i; + + for_each_possible_cpu(i) { + void *sp; + + sp = alloc_stack(ULONG_MAX, i); + critirq_ctx[i] = sp; + paca_ptrs[i]->crit_kstack = sp + THREAD_SIZE; + + sp = alloc_stack(ULONG_MAX, i); + dbgirq_ctx[i] = sp; + paca_ptrs[i]->dbg_kstack = sp + THREAD_SIZE; + + sp = alloc_stack(ULONG_MAX, i); + mcheckirq_ctx[i] = sp; + paca_ptrs[i]->mc_kstack = sp + THREAD_SIZE; + } + + if (cpu_has_feature(CPU_FTR_DEBUG_LVL_EXC)) + patch_exception(0x040, exc_debug_debug_book3e); +} +#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. + */ +void __init emergency_stack_init(void) +{ + u64 limit, mce_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, machine check, system reset, and HMI, we need to get + * at them in real mode. This means they must also be within the RMO + * region. + * + * The IRQ stacks allocated elsewhere in this file are zeroed and + * initialized in kernel/irq.c. These are initialized here in order + * to have emergency stacks available as early as possible. + */ + limit = mce_limit = min(ppc64_bolted_size(), ppc64_rma_size); + + /* + * Machine check on pseries calls rtas, but can't use the static + * rtas_args due to a machine check hitting while the lock is held. + * rtas args have to be under 4GB, so the machine check stack is + * limited to 4GB so args can be put on stack. + */ + if (firmware_has_feature(FW_FEATURE_LPAR) && mce_limit > SZ_4G) + mce_limit = SZ_4G; + + for_each_possible_cpu(i) { + paca_ptrs[i]->emergency_sp = alloc_stack(limit, i) + THREAD_SIZE; + +#ifdef CONFIG_PPC_BOOK3S_64 + /* emergency stack for NMI exception handling. */ + paca_ptrs[i]->nmi_emergency_sp = alloc_stack(limit, i) + THREAD_SIZE; + + /* emergency stack for machine check exception handling. */ + paca_ptrs[i]->mc_emergency_sp = alloc_stack(mce_limit, i) + THREAD_SIZE; +#endif + } +} + +#ifdef CONFIG_SMP +static int pcpu_cpu_distance(unsigned int from, unsigned int to) +{ + if (early_cpu_to_node(from) == early_cpu_to_node(to)) + return LOCAL_DISTANCE; + else + return REMOTE_DISTANCE; +} + +static __init int pcpu_cpu_to_node(int cpu) +{ + return early_cpu_to_node(cpu); +} + +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 = -EINVAL; + + /* + * BookE and BookS radix are historical values and should be revisited. + */ + if (IS_ENABLED(CONFIG_PPC_BOOK3E_64)) { + atom_size = SZ_1M; + } else if (radix_enabled()) { + atom_size = PAGE_SIZE; + } else if (IS_ENABLED(CONFIG_PPC_64S_HASH_MMU)) { + /* + * 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 = SZ_1M; + } + + if (pcpu_chosen_fc != PCPU_FC_PAGE) { + rc = pcpu_embed_first_chunk(0, dyn_size, atom_size, pcpu_cpu_distance, + pcpu_cpu_to_node); + if (rc) + pr_warn("PERCPU: %s allocator failed (%d), " + "falling back to page size\n", + pcpu_fc_names[pcpu_chosen_fc], rc); + } + + if (rc < 0) + rc = pcpu_page_first_chunk(0, pcpu_cpu_to_node); + 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_ptrs[cpu]->data_offset = __per_cpu_offset[cpu]; + } +} +#endif + +#ifdef CONFIG_MEMORY_HOTPLUG +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_PERF +u64 hw_nmi_get_sample_period(int watchdog_thresh) +{ + return ppc_proc_freq * watchdog_thresh; +} +#endif + +/* + * The perf based hardlockup detector breaks PMU event based branches, so + * disable it by default. Book3S has a soft-nmi hardlockup detector based + * on the decrementer interrupt, so it does not suffer from this problem. + * + * It is likely to get false positives in KVM guests, so disable it there + * by default too. PowerVM will not stop or arbitrarily oversubscribe + * CPUs, but give a minimum regular allotment even with SPLPAR, so enable + * the detector for non-KVM guests, assume PowerVM. + */ +static int __init disable_hardlockup_detector(void) +{ +#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF + hardlockup_detector_disable(); +#else + if (firmware_has_feature(FW_FEATURE_LPAR)) { + if (is_kvm_guest()) + hardlockup_detector_disable(); + } +#endif + + return 0; +} +early_initcall(disable_hardlockup_detector); |