diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/hotplug-cpu.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/hotplug-cpu.c | 975 |
1 files changed, 975 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c new file mode 100644 index 000000000..8bfb97d07 --- /dev/null +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -0,0 +1,975 @@ +/* + * 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. + */ + +#define pr_fmt(fmt) "pseries-hotplug-cpu: " fmt + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/delay.h> +#include <linux/sched.h> /* for idle_task_exit */ +#include <linux/sched/hotplug.h> +#include <linux/cpu.h> +#include <linux/of.h> +#include <linux/slab.h> +#include <asm/prom.h> +#include <asm/rtas.h> +#include <asm/firmware.h> +#include <asm/machdep.h> +#include <asm/vdso_datapage.h> +#include <asm/xics.h> +#include <asm/xive.h> +#include <asm/plpar_wrappers.h> +#include <asm/topology.h> + +#include "pseries.h" +#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 bool cede_offline_enabled __read_mostly = true; + +/* + * Enable/disable cede_offline when available. + */ +static int __init setup_cede_offline(char *str) +{ + return (kstrtobool(str, &cede_offline_enabled) == 0); +} + +__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; + + local_irq_disable(); + + BUG_ON(rtas_stop_self_token == RTAS_UNKNOWN_SERVICE); + + rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL); + + 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(); + if (xive_enabled()) + xive_teardown_cpu(); + else + 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 */ + if (xive_enabled()) + xive_smp_disable_cpu(); + else + 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_ptrs[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 %pOF; this system configuration" + " supports %d logical cpus.\n", np, + 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); + update_numa_cpu_lookup_table(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 dlpar_online_cpu(struct device_node *dn) +{ + int rc = 0; + unsigned int cpu; + int len, nthreads, i; + const __be32 *intserv; + u32 thread; + + intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len); + if (!intserv) + return -EINVAL; + + 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(get_cpu_current_state(cpu) + != CPU_STATE_OFFLINE); + cpu_maps_update_done(); + timed_topology_update(1); + find_and_online_cpu_nid(cpu); + rc = device_online(get_cpu_device(cpu)); + if (rc) + goto out; + cpu_maps_update_begin(); + + break; + } + if (cpu == num_possible_cpus()) + printk(KERN_WARNING "Could not find cpu to online " + "with physical id 0x%x\n", thread); + } + cpu_maps_update_done(); + +out: + return rc; + +} + +static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index) +{ + struct device_node *child = NULL; + u32 my_drc_index; + bool found; + int rc; + + /* Assume cpu doesn't exist */ + found = false; + + for_each_child_of_node(parent, child) { + rc = of_property_read_u32(child, "ibm,my-drc-index", + &my_drc_index); + if (rc) + continue; + + if (my_drc_index == drc_index) { + of_node_put(child); + found = true; + break; + } + } + + return found; +} + +static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index) +{ + bool found = false; + int rc, index; + + index = 0; + while (!found) { + u32 drc; + + rc = of_property_read_u32_index(parent, "ibm,drc-indexes", + index++, &drc); + if (rc) + break; + + if (drc == drc_index) + found = true; + } + + return found; +} + +static ssize_t dlpar_cpu_add(u32 drc_index) +{ + struct device_node *dn, *parent; + int rc, saved_rc; + + pr_debug("Attempting to add CPU, drc index: %x\n", drc_index); + + parent = of_find_node_by_path("/cpus"); + if (!parent) { + pr_warn("Failed to find CPU root node \"/cpus\"\n"); + return -ENODEV; + } + + if (dlpar_cpu_exists(parent, drc_index)) { + of_node_put(parent); + pr_warn("CPU with drc index %x already exists\n", drc_index); + return -EINVAL; + } + + if (!valid_cpu_drc_index(parent, drc_index)) { + of_node_put(parent); + pr_warn("Cannot find CPU (drc index %x) to add.\n", drc_index); + return -EINVAL; + } + + rc = dlpar_acquire_drc(drc_index); + if (rc) { + pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n", + rc, drc_index); + of_node_put(parent); + return -EINVAL; + } + + dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent); + if (!dn) { + pr_warn("Failed call to configure-connector, drc index: %x\n", + drc_index); + dlpar_release_drc(drc_index); + of_node_put(parent); + return -EINVAL; + } + + rc = dlpar_attach_node(dn, parent); + + /* Regardless we are done with parent now */ + of_node_put(parent); + + if (rc) { + saved_rc = rc; + pr_warn("Failed to attach node %s, rc: %d, drc index: %x\n", + dn->name, rc, drc_index); + + rc = dlpar_release_drc(drc_index); + if (!rc) + dlpar_free_cc_nodes(dn); + + return saved_rc; + } + + rc = dlpar_online_cpu(dn); + if (rc) { + saved_rc = rc; + pr_warn("Failed to online cpu %s, rc: %d, drc index: %x\n", + dn->name, rc, drc_index); + + rc = dlpar_detach_node(dn); + if (!rc) + dlpar_release_drc(drc_index); + + return saved_rc; + } + + pr_debug("Successfully added CPU %s, drc index: %x\n", dn->name, + drc_index); + return rc; +} + +static int dlpar_offline_cpu(struct device_node *dn) +{ + int rc = 0; + unsigned int cpu; + int len, nthreads, i; + const __be32 *intserv; + u32 thread; + + intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s", &len); + if (!intserv) + return -EINVAL; + + 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; + + if (get_cpu_current_state(cpu) == CPU_STATE_OFFLINE) + break; + + if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) { + set_preferred_offline_state(cpu, + CPU_STATE_OFFLINE); + cpu_maps_update_done(); + timed_topology_update(1); + rc = device_offline(get_cpu_device(cpu)); + if (rc) + goto out; + cpu_maps_update_begin(); + break; + + } + + /* + * The cpu is in CPU_STATE_INACTIVE. + * Upgrade it's state to CPU_STATE_OFFLINE. + */ + set_preferred_offline_state(cpu, CPU_STATE_OFFLINE); + BUG_ON(plpar_hcall_norets(H_PROD, thread) + != H_SUCCESS); + __cpu_die(cpu); + break; + } + if (cpu == num_possible_cpus()) + printk(KERN_WARNING "Could not find cpu to offline with physical id 0x%x\n", thread); + } + cpu_maps_update_done(); + +out: + return rc; + +} + +static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index) +{ + int rc; + + pr_debug("Attempting to remove CPU %s, drc index: %x\n", + dn->name, drc_index); + + rc = dlpar_offline_cpu(dn); + if (rc) { + pr_warn("Failed to offline CPU %s, rc: %d\n", dn->name, rc); + return -EINVAL; + } + + rc = dlpar_release_drc(drc_index); + if (rc) { + pr_warn("Failed to release drc (%x) for CPU %s, rc: %d\n", + drc_index, dn->name, rc); + dlpar_online_cpu(dn); + return rc; + } + + rc = dlpar_detach_node(dn); + if (rc) { + int saved_rc = rc; + + pr_warn("Failed to detach CPU %s, rc: %d", dn->name, rc); + + rc = dlpar_acquire_drc(drc_index); + if (!rc) + dlpar_online_cpu(dn); + + return saved_rc; + } + + pr_debug("Successfully removed CPU, drc index: %x\n", drc_index); + return 0; +} + +static struct device_node *cpu_drc_index_to_dn(u32 drc_index) +{ + struct device_node *dn; + u32 my_index; + int rc; + + for_each_node_by_type(dn, "cpu") { + rc = of_property_read_u32(dn, "ibm,my-drc-index", &my_index); + if (rc) + continue; + + if (my_index == drc_index) + break; + } + + return dn; +} + +static int dlpar_cpu_remove_by_index(u32 drc_index) +{ + struct device_node *dn; + int rc; + + dn = cpu_drc_index_to_dn(drc_index); + if (!dn) { + pr_warn("Cannot find CPU (drc index %x) to remove\n", + drc_index); + return -ENODEV; + } + + rc = dlpar_cpu_remove(dn, drc_index); + of_node_put(dn); + return rc; +} + +static int find_dlpar_cpus_to_remove(u32 *cpu_drcs, int cpus_to_remove) +{ + struct device_node *dn; + int cpus_found = 0; + int rc; + + /* We want to find cpus_to_remove + 1 CPUs to ensure we do not + * remove the last CPU. + */ + for_each_node_by_type(dn, "cpu") { + cpus_found++; + + if (cpus_found > cpus_to_remove) { + of_node_put(dn); + break; + } + + /* Note that cpus_found is always 1 ahead of the index + * into the cpu_drcs array, so we use cpus_found - 1 + */ + rc = of_property_read_u32(dn, "ibm,my-drc-index", + &cpu_drcs[cpus_found - 1]); + if (rc) { + pr_warn("Error occurred getting drc-index for %s\n", + dn->name); + of_node_put(dn); + return -1; + } + } + + if (cpus_found < cpus_to_remove) { + pr_warn("Failed to find enough CPUs (%d of %d) to remove\n", + cpus_found, cpus_to_remove); + } else if (cpus_found == cpus_to_remove) { + pr_warn("Cannot remove all CPUs\n"); + } + + return cpus_found; +} + +static int dlpar_cpu_remove_by_count(u32 cpus_to_remove) +{ + u32 *cpu_drcs; + int cpus_found; + int cpus_removed = 0; + int i, rc; + + pr_debug("Attempting to hot-remove %d CPUs\n", cpus_to_remove); + + cpu_drcs = kcalloc(cpus_to_remove, sizeof(*cpu_drcs), GFP_KERNEL); + if (!cpu_drcs) + return -EINVAL; + + cpus_found = find_dlpar_cpus_to_remove(cpu_drcs, cpus_to_remove); + if (cpus_found <= cpus_to_remove) { + kfree(cpu_drcs); + return -EINVAL; + } + + for (i = 0; i < cpus_to_remove; i++) { + rc = dlpar_cpu_remove_by_index(cpu_drcs[i]); + if (rc) + break; + + cpus_removed++; + } + + if (cpus_removed != cpus_to_remove) { + pr_warn("CPU hot-remove failed, adding back removed CPUs\n"); + + for (i = 0; i < cpus_removed; i++) + dlpar_cpu_add(cpu_drcs[i]); + + rc = -EINVAL; + } else { + rc = 0; + } + + kfree(cpu_drcs); + return rc; +} + +static int find_dlpar_cpus_to_add(u32 *cpu_drcs, u32 cpus_to_add) +{ + struct device_node *parent; + int cpus_found = 0; + int index, rc; + + parent = of_find_node_by_path("/cpus"); + if (!parent) { + pr_warn("Could not find CPU root node in device tree\n"); + kfree(cpu_drcs); + return -1; + } + + /* Search the ibm,drc-indexes array for possible CPU drcs to + * add. Note that the format of the ibm,drc-indexes array is + * the number of entries in the array followed by the array + * of drc values so we start looking at index = 1. + */ + index = 1; + while (cpus_found < cpus_to_add) { + u32 drc; + + rc = of_property_read_u32_index(parent, "ibm,drc-indexes", + index++, &drc); + if (rc) + break; + + if (dlpar_cpu_exists(parent, drc)) + continue; + + cpu_drcs[cpus_found++] = drc; + } + + of_node_put(parent); + return cpus_found; +} + +static int dlpar_cpu_add_by_count(u32 cpus_to_add) +{ + u32 *cpu_drcs; + int cpus_added = 0; + int cpus_found; + int i, rc; + + pr_debug("Attempting to hot-add %d CPUs\n", cpus_to_add); + + cpu_drcs = kcalloc(cpus_to_add, sizeof(*cpu_drcs), GFP_KERNEL); + if (!cpu_drcs) + return -EINVAL; + + cpus_found = find_dlpar_cpus_to_add(cpu_drcs, cpus_to_add); + if (cpus_found < cpus_to_add) { + pr_warn("Failed to find enough CPUs (%d of %d) to add\n", + cpus_found, cpus_to_add); + kfree(cpu_drcs); + return -EINVAL; + } + + for (i = 0; i < cpus_to_add; i++) { + rc = dlpar_cpu_add(cpu_drcs[i]); + if (rc) + break; + + cpus_added++; + } + + if (cpus_added < cpus_to_add) { + pr_warn("CPU hot-add failed, removing any added CPUs\n"); + + for (i = 0; i < cpus_added; i++) + dlpar_cpu_remove_by_index(cpu_drcs[i]); + + rc = -EINVAL; + } else { + rc = 0; + } + + kfree(cpu_drcs); + return rc; +} + +int dlpar_cpu_readd(int cpu) +{ + struct device_node *dn; + struct device *dev; + u32 drc_index; + int rc; + + dev = get_cpu_device(cpu); + dn = dev->of_node; + + rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index); + + rc = dlpar_cpu_remove_by_index(drc_index); + if (!rc) + rc = dlpar_cpu_add(drc_index); + + return rc; +} + +int dlpar_cpu(struct pseries_hp_errorlog *hp_elog) +{ + u32 count, drc_index; + int rc; + + count = hp_elog->_drc_u.drc_count; + drc_index = hp_elog->_drc_u.drc_index; + + lock_device_hotplug(); + + switch (hp_elog->action) { + case PSERIES_HP_ELOG_ACTION_REMOVE: + if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) + rc = dlpar_cpu_remove_by_count(count); + else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) + rc = dlpar_cpu_remove_by_index(drc_index); + else + rc = -EINVAL; + break; + case PSERIES_HP_ELOG_ACTION_ADD: + if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT) + rc = dlpar_cpu_add_by_count(count); + else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX) + rc = dlpar_cpu_add(drc_index); + else + rc = -EINVAL; + break; + default: + pr_err("Invalid action (%d) specified\n", hp_elog->action); + rc = -EINVAL; + break; + } + + unlock_device_hotplug(); + return rc; +} + +#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE + +static ssize_t dlpar_cpu_probe(const char *buf, size_t count) +{ + u32 drc_index; + int rc; + + rc = kstrtou32(buf, 0, &drc_index); + if (rc) + return -EINVAL; + + rc = dlpar_cpu_add(drc_index); + + return rc ? rc : count; +} + +static ssize_t dlpar_cpu_release(const char *buf, size_t count) +{ + struct device_node *dn; + u32 drc_index; + int rc; + + dn = of_find_node_by_path(buf); + if (!dn) + return -EINVAL; + + rc = of_property_read_u32(dn, "ibm,my-drc-index", &drc_index); + if (rc) { + of_node_put(dn); + return -EINVAL; + } + + rc = dlpar_cpu_remove(dn, drc_index); + of_node_put(dn); + + return rc ? rc : count; +} + +#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ + +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) +{ + int cpu; + int qcss_tok; + +#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE + ppc_md.cpu_probe = dlpar_cpu_probe; + ppc_md.cpu_release = dlpar_cpu_release; +#endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */ + + 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); |