From 90edf184b9b7275d248f1b9902733a0000e4ecf8 Mon Sep 17 00:00:00 2001 From: Nathan Fontenot Date: Wed, 16 Dec 2015 14:55:07 -0600 Subject: [PATCH] powerpc/pseries: Add CPU dlpar add functionality Add the ability to hotplug add cpus via rtas hotplug events by either specifying the drc index of the CPU to add, or providing a count of the number of CPUs to add. Signed-off-by: Nathan Fontenot Signed-off-by: Michael Ellerman --- arch/powerpc/platforms/pseries/hotplug-cpu.c | 116 +++++++++++++++++++ 1 file changed, 116 insertions(+) diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c index 86c7ae3db50e..32274f72fe3f 100644 --- a/arch/powerpc/platforms/pseries/hotplug-cpu.c +++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c @@ -405,6 +405,27 @@ static bool dlpar_cpu_exists(struct device_node *parent, u32 drc_index) 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; @@ -424,6 +445,12 @@ static ssize_t dlpar_cpu_add(u32 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", @@ -683,6 +710,87 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove) 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; @@ -702,6 +810,14 @@ int dlpar_cpu(struct pseries_hp_errorlog *hp_elog) 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; -- GitLab