diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/hotplug-cpu.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/hotplug-cpu.c | 550 |
1 files changed, 542 insertions, 8 deletions
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 62475440fd45..32274f72fe3f 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -18,12 +18,15 @@ * 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/cpu.h> #include <linux/of.h> +#include <linux/slab.h> #include <asm/prom.h> #include <asm/rtas.h> #include <asm/firmware.h> @@ -32,6 +35,7 @@ #include <asm/xics.h> #include <asm/plpar_wrappers.h> +#include "pseries.h" #include "offline_states.h" /* This version can't take the spinlock, because it never returns */ @@ -88,13 +92,7 @@ void set_default_offline_state(int cpu) 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); + static struct rtas_args args; local_irq_disable(); @@ -102,7 +100,8 @@ static void rtas_stop_self(void) printk("cpu %u (hwid %u) Ready to die...\n", smp_processor_id(), hard_smp_processor_id()); - enter_rtas(__pa(&args)); + + rtas_call_unlocked(&args, rtas_stop_self_token, 0, 1, NULL); panic("Alas, I survived.\n"); } @@ -339,6 +338,536 @@ static void pseries_remove_processor(struct device_node *np) 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(); + 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); + of_node_put(parent); + if (!dn) { + pr_warn("Failed call to configure-connector, drc index: %x\n", + drc_index); + dlpar_release_drc(drc_index); + return -EINVAL; + } + + rc = dlpar_attach_node(dn); + 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(); + 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("Attemping 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(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) { @@ -385,6 +914,11 @@ 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 */ + for_each_node_by_name(np, "interrupt-controller") { typep = of_get_property(np, "compatible", NULL); if (strstr(typep, "open-pic")) { |