Patch creates a file "nest-pmu-c" to contain nest pmu related functions. Patch adds nest pmu init function and cpumask function since Nest pmu units are per-chip. First online cpu for a given node is picked as designated thread to read the counter data.
Subsequent patch adds the hotplug support. Cc: Michael Ellerman <m...@ellerman.id.au> Cc: Benjamin Herrenschmidt <b...@kernel.crashing.org> Cc: Paul Mackerras <pau...@samba.org> Cc: Sukadev Bhattiprolu <suka...@linux.vnet.ibm.com> Cc: Anshuman Khandual <khand...@linux.vnet.ibm.com> Cc: Stephane Eranian <eran...@google.com> Cc: Preeti U Murthy <pre...@linux.vnet.ibm.com> Cc: Ingo Molnar <mi...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Signed-off-by: Madhavan Srinivasan <ma...@linux.vnet.ibm.com> --- arch/powerpc/perf/nest-pmu.c | 70 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 arch/powerpc/perf/nest-pmu.c diff --git a/arch/powerpc/perf/nest-pmu.c b/arch/powerpc/perf/nest-pmu.c new file mode 100644 index 0000000..d4413bb --- /dev/null +++ b/arch/powerpc/perf/nest-pmu.c @@ -0,0 +1,70 @@ +/* + * Nest Performance Monitor counter support for POWER8 processors. + * + * Copyright 2015 Madhavan Srinivasan, 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 "nest-pmu.h" + +static cpumask_t cpu_mask_nest_pmu; + +static ssize_t cpumask_nest_pmu_get_attr(struct device *dev, + struct device_attribute *attr, char *buf) +{ + return cpumap_print_to_pagebuf(true, buf, &cpu_mask_nest_pmu); +} + +static DEVICE_ATTR(cpumask, S_IRUGO, cpumask_nest_pmu_get_attr, NULL); + +static struct attribute *cpumask_nest_pmu_attrs[] = { + &dev_attr_cpumask.attr, + NULL, +}; + +static struct attribute_group cpumask_nest_pmu_attr_group = { + .attrs = cpumask_nest_pmu_attrs, +}; + +void cpumask_chip(void) +{ + const struct cpumask *l_cpumask; + int cpu, nid; + + if (!cpumask_empty(&cpu_mask_nest_pmu)) { + printk(KERN_INFO "cpumask not empty\n"); + return; + } + + cpu_notifier_register_begin(); + for_each_online_node(nid) { + l_cpumask = cpumask_of_node(nid); + cpu = cpumask_first(l_cpumask); + cpumask_set_cpu(cpu, &cpu_mask_nest_pmu); + } + + cpu_notifier_register_done(); +} + + +static int __init nest_pmu_init(void) +{ + int ret = 0; + + /* + * Lets do this only if we are hypervisor + */ + if (!cur_cpu_spec->oprofile_cpu_type || + strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power8") || + !cpu_has_feature(CPU_FTR_HVMODE)) + return ret; + + cpumask_chip(); + + return 0; +} +device_initcall(nest_pmu_init); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/