From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- .../arch/powerpc/platforms/pseries/hotplug-cpu.c | 427 +++++++++++++++++++++ 1 file changed, 427 insertions(+) create mode 100644 kernel/arch/powerpc/platforms/pseries/hotplug-cpu.c (limited to 'kernel/arch/powerpc/platforms/pseries/hotplug-cpu.c') diff --git a/kernel/arch/powerpc/platforms/pseries/hotplug-cpu.c b/kernel/arch/powerpc/platforms/pseries/hotplug-cpu.c new file mode 100644 index 000000000..62475440f --- /dev/null +++ b/kernel/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -0,0 +1,427 @@ +/* + * pseries CPU Hotplug infrastructure. + * + * Split out from arch/powerpc/platforms/pseries/setup.c + * arch/powerpc/kernel/rtas.c, and arch/powerpc/platforms/pseries/smp.c + * + * Peter Bergner, IBM March 2001. + * Copyright (C) 2001 IBM. + * Dave Engebretsen, Peter Bergner, and + * Mike Corrigan {engebret|bergner|mikec}@us.ibm.com + * Plus various changes from other IBM teams... + * + * Copyright (C) 2006 Michael Ellerman, IBM Corporation + * + * 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. + */ + +#include +#include +#include +#include /* for idle_task_exit */ +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "offline_states.h" + +/* This version can't take the spinlock, because it never returns */ +static int rtas_stop_self_token = RTAS_UNKNOWN_SERVICE; + +static DEFINE_PER_CPU(enum cpu_state_vals, preferred_offline_state) = + CPU_STATE_OFFLINE; +static DEFINE_PER_CPU(enum cpu_state_vals, current_state) = CPU_STATE_OFFLINE; + +static enum cpu_state_vals default_offline_state = CPU_STATE_OFFLINE; + +static int cede_offline_enabled __read_mostly = 1; + +/* + * Enable/disable cede_offline when available. + */ +static int __init setup_cede_offline(char *str) +{ + if (!strcmp(str, "off")) + cede_offline_enabled = 0; + else if (!strcmp(str, "on")) + cede_offline_enabled = 1; + else + return 0; + return 1; +} + +__setup("cede_offline=", setup_cede_offline); + +enum cpu_state_vals get_cpu_current_state(int cpu) +{ + return per_cpu(current_state, cpu); +} + +void set_cpu_current_state(int cpu, enum cpu_state_vals state) +{ + per_cpu(current_state, cpu) = state; +} + +enum cpu_state_vals get_preferred_offline_state(int cpu) +{ + return per_cpu(preferred_offline_state, cpu); +} + +void set_preferred_offline_state(int cpu, enum cpu_state_vals state) +{ + per_cpu(preferred_offline_state, cpu) = state; +} + +void set_default_offline_state(int cpu) +{ + per_cpu(preferred_offline_state, cpu) = default_offline_state; +} + +static void rtas_stop_self(void) +{ + static struct rtas_args args = { + .nargs = 0, + .nret = cpu_to_be32(1), + .rets = &args.args[0], + }; + + args.token = cpu_to_be32(rtas_stop_self_token); + + local_irq_disable(); + + BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE); + + printk("cpu %u (hwid %u) Ready to die...\n", + smp_processor_id(), hard_smp_processor_id()); + enter_rtas(__pa(&args)); + + panic("Alas, I survived.\n"); +} + +static void pseries_mach_cpu_die(void) +{ + unsigned int cpu = smp_processor_id(); + unsigned int hwcpu = hard_smp_processor_id(); + u8 cede_latency_hint = 0; + + local_irq_disable(); + idle_task_exit(); + xics_teardown_cpu(); + + if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) { + set_cpu_current_state(cpu, CPU_STATE_INACTIVE); + if (ppc_md.suspend_disable_cpu) + ppc_md.suspend_disable_cpu(); + + cede_latency_hint = 2; + + get_lppaca()->idle = 1; + if (!lppaca_shared_proc(get_lppaca())) + get_lppaca()->donate_dedicated_cpu = 1; + + while (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) { + while (!prep_irq_for_idle()) { + local_irq_enable(); + local_irq_disable(); + } + + extended_cede_processor(cede_latency_hint); + } + + local_irq_disable(); + + if (!lppaca_shared_proc(get_lppaca())) + get_lppaca()->donate_dedicated_cpu = 0; + get_lppaca()->idle = 0; + + if (get_preferred_offline_state(cpu) == CPU_STATE_ONLINE) { + unregister_slb_shadow(hwcpu); + + hard_irq_disable(); + /* + * Call to start_secondary_resume() will not return. + * Kernel stack will be reset and start_secondary() + * will be called to continue the online operation. + */ + start_secondary_resume(); + } + } + + /* Requested state is CPU_STATE_OFFLINE at this point */ + WARN_ON(get_preferred_offline_state(cpu) != CPU_STATE_OFFLINE); + + set_cpu_current_state(cpu, CPU_STATE_OFFLINE); + unregister_slb_shadow(hwcpu); + rtas_stop_self(); + + /* Should never get here... */ + BUG(); + for(;;); +} + +static int pseries_cpu_disable(void) +{ + int cpu = smp_processor_id(); + + set_cpu_online(cpu, false); + vdso_data->processorCount--; + + /*fix boot_cpuid here*/ + if (cpu == boot_cpuid) + boot_cpuid = cpumask_any(cpu_online_mask); + + /* FIXME: abstract this to not be platform specific later on */ + xics_migrate_irqs_away(); + return 0; +} + +/* + * pseries_cpu_die: Wait for the cpu to die. + * @cpu: logical processor id of the CPU whose death we're awaiting. + * + * This function is called from the context of the thread which is performing + * the cpu-offline. Here we wait for long enough to allow the cpu in question + * to self-destroy so that the cpu-offline thread can send the CPU_DEAD + * notifications. + * + * OTOH, pseries_mach_cpu_die() is called by the @cpu when it wants to + * self-destruct. + */ +static void pseries_cpu_die(unsigned int cpu) +{ + int tries; + int cpu_status = 1; + unsigned int pcpu = get_hard_smp_processor_id(cpu); + + if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) { + cpu_status = 1; + for (tries = 0; tries < 5000; tries++) { + if (get_cpu_current_state(cpu) == CPU_STATE_INACTIVE) { + cpu_status = 0; + break; + } + msleep(1); + } + } else if (get_preferred_offline_state(cpu) == CPU_STATE_OFFLINE) { + + for (tries = 0; tries < 25; tries++) { + cpu_status = smp_query_cpu_stopped(pcpu); + if (cpu_status == QCSS_STOPPED || + cpu_status == QCSS_HARDWARE_ERROR) + break; + cpu_relax(); + } + } + + if (cpu_status != 0) { + printk("Querying DEAD? cpu %i (%i) shows %i\n", + cpu, pcpu, cpu_status); + } + + /* Isolation and deallocation are definitely done by + * drslot_chrp_cpu. If they were not they would be + * done here. Change isolate state to Isolate and + * change allocation-state to Unusable. + */ + paca[cpu].cpu_start = 0; +} + +/* + * Update cpu_present_mask and paca(s) for a new cpu node. The wrinkle + * here is that a cpu device node may represent up to two logical cpus + * in the SMT case. We must honor the assumption in other code that + * the logical ids for sibling SMT threads x and y are adjacent, such + * that x^1 == y and y^1 == x. + */ +static int pseries_add_processor(struct device_node *np) +{ + unsigned int cpu; + cpumask_var_t candidate_mask, tmp; + int err = -ENOSPC, len, nthreads, i; + const __be32 *intserv; + + intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len); + if (!intserv) + return 0; + + zalloc_cpumask_var(&candidate_mask, GFP_KERNEL); + zalloc_cpumask_var(&tmp, GFP_KERNEL); + + nthreads = len / sizeof(u32); + for (i = 0; i < nthreads; i++) + cpumask_set_cpu(i, tmp); + + cpu_maps_update_begin(); + + BUG_ON(!cpumask_subset(cpu_present_mask, cpu_possible_mask)); + + /* Get a bitmap of unoccupied slots. */ + cpumask_xor(candidate_mask, cpu_possible_mask, cpu_present_mask); + if (cpumask_empty(candidate_mask)) { + /* If we get here, it most likely means that NR_CPUS is + * less than the partition's max processors setting. + */ + printk(KERN_ERR "Cannot add cpu %s; this system configuration" + " supports %d logical cpus.\n", np->full_name, + num_possible_cpus()); + goto out_unlock; + } + + while (!cpumask_empty(tmp)) + if (cpumask_subset(tmp, candidate_mask)) + /* Found a range where we can insert the new cpu(s) */ + break; + else + cpumask_shift_left(tmp, tmp, nthreads); + + if (cpumask_empty(tmp)) { + printk(KERN_ERR "Unable to find space in cpu_present_mask for" + " processor %s with %d thread(s)\n", np->name, + nthreads); + goto out_unlock; + } + + for_each_cpu(cpu, tmp) { + BUG_ON(cpu_present(cpu)); + set_cpu_present(cpu, true); + set_hard_smp_processor_id(cpu, be32_to_cpu(*intserv++)); + } + err = 0; +out_unlock: + cpu_maps_update_done(); + free_cpumask_var(candidate_mask); + free_cpumask_var(tmp); + return err; +} + +/* + * Update the present map for a cpu node which is going away, and set + * the hard id in the paca(s) to -1 to be consistent with boot time + * convention for non-present cpus. + */ +static void pseries_remove_processor(struct device_node *np) +{ + unsigned int cpu; + int len, nthreads, i; + const __be32 *intserv; + u32 thread; + + intserv = of_get_property(np, "ibm,ppc-interrupt-server#s", &len); + if (!intserv) + return; + + nthreads = len / sizeof(u32); + + cpu_maps_update_begin(); + for (i = 0; i < nthreads; i++) { + thread = be32_to_cpu(intserv[i]); + for_each_present_cpu(cpu) { + if (get_hard_smp_processor_id(cpu) != thread) + continue; + BUG_ON(cpu_online(cpu)); + set_cpu_present(cpu, false); + set_hard_smp_processor_id(cpu, -1); + break; + } + if (cpu >= nr_cpu_ids) + printk(KERN_WARNING "Could not find cpu to remove " + "with physical id 0x%x\n", thread); + } + cpu_maps_update_done(); +} + +static int pseries_smp_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct of_reconfig_data *rd = data; + int err = 0; + + switch (action) { + case OF_RECONFIG_ATTACH_NODE: + err = pseries_add_processor(rd->dn); + break; + case OF_RECONFIG_DETACH_NODE: + pseries_remove_processor(rd->dn); + break; + } + return notifier_from_errno(err); +} + +static struct notifier_block pseries_smp_nb = { + .notifier_call = pseries_smp_notifier, +}; + +#define MAX_CEDE_LATENCY_LEVELS 4 +#define CEDE_LATENCY_PARAM_LENGTH 10 +#define CEDE_LATENCY_PARAM_MAX_LENGTH \ + (MAX_CEDE_LATENCY_LEVELS * CEDE_LATENCY_PARAM_LENGTH * sizeof(char)) +#define CEDE_LATENCY_TOKEN 45 + +static char cede_parameters[CEDE_LATENCY_PARAM_MAX_LENGTH]; + +static int parse_cede_parameters(void) +{ + memset(cede_parameters, 0, CEDE_LATENCY_PARAM_MAX_LENGTH); + return rtas_call(rtas_token("ibm,get-system-parameter"), 3, 1, + NULL, + CEDE_LATENCY_TOKEN, + __pa(cede_parameters), + CEDE_LATENCY_PARAM_MAX_LENGTH); +} + +static int __init pseries_cpu_hotplug_init(void) +{ + struct device_node *np; + const char *typep; + int cpu; + int qcss_tok; + + for_each_node_by_name(np, "interrupt-controller") { + typep = of_get_property(np, "compatible", NULL); + if (strstr(typep, "open-pic")) { + of_node_put(np); + + printk(KERN_INFO "CPU Hotplug not supported on " + "systems using MPIC\n"); + return 0; + } + } + + rtas_stop_self_token = rtas_token("stop-self"); + qcss_tok = rtas_token("query-cpu-stopped-state"); + + if (rtas_stop_self_token == RTAS_UNKNOWN_SERVICE || + qcss_tok == RTAS_UNKNOWN_SERVICE) { + printk(KERN_INFO "CPU Hotplug not supported by firmware " + "- disabling.\n"); + return 0; + } + + ppc_md.cpu_die = pseries_mach_cpu_die; + smp_ops->cpu_disable = pseries_cpu_disable; + smp_ops->cpu_die = pseries_cpu_die; + + /* Processors can be added/removed only on LPAR */ + if (firmware_has_feature(FW_FEATURE_LPAR)) { + of_reconfig_notifier_register(&pseries_smp_nb); + cpu_maps_update_begin(); + if (cede_offline_enabled && parse_cede_parameters() == 0) { + default_offline_state = CPU_STATE_INACTIVE; + for_each_online_cpu(cpu) + set_default_offline_state(cpu); + } + cpu_maps_update_done(); + } + + return 0; +} +machine_arch_initcall(pseries, pseries_cpu_hotplug_init); -- cgit 1.2.3-korg