diff options
Diffstat (limited to 'arch/x86/kernel/cpu/intel_rdt_rdtgroup.c')
| -rw-r--r-- | arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 131 |
1 files changed, 129 insertions, 2 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c index 85d31eacabe0..e05a18685fc8 100644 --- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c +++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c @@ -20,6 +20,7 @@ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/cpu.h> #include <linux/fs.h> #include <linux/sysfs.h> #include <linux/kernfs.h> @@ -172,6 +173,111 @@ static struct kernfs_ops rdtgroup_kf_single_ops = { .seq_show = rdtgroup_seqfile_show, }; +static int rdtgroup_cpus_show(struct kernfs_open_file *of, + struct seq_file *s, void *v) +{ + struct rdtgroup *rdtgrp; + int ret = 0; + + rdtgrp = rdtgroup_kn_lock_live(of->kn); + + if (rdtgrp) + seq_printf(s, "%*pb\n", cpumask_pr_args(&rdtgrp->cpu_mask)); + else + ret = -ENOENT; + rdtgroup_kn_unlock(of->kn); + + return ret; +} + +static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, + char *buf, size_t nbytes, loff_t off) +{ + cpumask_var_t tmpmask, newmask; + struct rdtgroup *rdtgrp, *r; + int ret, cpu; + + if (!buf) + return -EINVAL; + + if (!zalloc_cpumask_var(&tmpmask, GFP_KERNEL)) + return -ENOMEM; + if (!zalloc_cpumask_var(&newmask, GFP_KERNEL)) { + free_cpumask_var(tmpmask); + return -ENOMEM; + } + rdtgrp = rdtgroup_kn_lock_live(of->kn); + if (!rdtgrp) { + ret = -ENOENT; + goto unlock; + } + + ret = cpumask_parse(buf, newmask); + if (ret) + goto unlock; + + get_online_cpus(); + /* check that user didn't specify any offline cpus */ + cpumask_andnot(tmpmask, newmask, cpu_online_mask); + if (cpumask_weight(tmpmask)) { + ret = -EINVAL; + goto end; + } + + /* Check whether cpus are dropped from this group */ + cpumask_andnot(tmpmask, &rdtgrp->cpu_mask, newmask); + if (cpumask_weight(tmpmask)) { + /* Can't drop from default group */ + if (rdtgrp == &rdtgroup_default) { + ret = -EINVAL; + goto end; + } + /* Give any dropped cpus to rdtgroup_default */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, tmpmask); + for_each_cpu(cpu, tmpmask) + per_cpu(cpu_closid, cpu) = 0; + } + + /* + * If we added cpus, remove them from previous group that owned them + * and update per-cpu closid + */ + cpumask_andnot(tmpmask, newmask, &rdtgrp->cpu_mask); + if (cpumask_weight(tmpmask)) { + list_for_each_entry(r, &rdt_all_groups, rdtgroup_list) { + if (r == rdtgrp) + continue; + cpumask_andnot(&r->cpu_mask, &r->cpu_mask, tmpmask); + } + for_each_cpu(cpu, tmpmask) + per_cpu(cpu_closid, cpu) = rdtgrp->closid; + } + + /* Done pushing/pulling - update this group with new mask */ + cpumask_copy(&rdtgrp->cpu_mask, newmask); + +end: + put_online_cpus(); +unlock: + rdtgroup_kn_unlock(of->kn); + free_cpumask_var(tmpmask); + free_cpumask_var(newmask); + + return ret ?: nbytes; +} + +/* Files in each rdtgroup */ +static struct rftype rdtgroup_base_files[] = { + { + .name = "cpus", + .mode = 0644, + .kf_ops = &rdtgroup_kf_single_ops, + .write = rdtgroup_cpus_write, + .seq_show = rdtgroup_cpus_show, + }, +}; + static int rdt_num_closids_show(struct kernfs_open_file *of, struct seq_file *seq, void *v) { @@ -582,6 +688,11 @@ static int rdtgroup_mkdir(struct kernfs_node *parent_kn, const char *name, if (ret) goto out_destroy; + ret = rdtgroup_add_files(kn, rdtgroup_base_files, + ARRAY_SIZE(rdtgroup_base_files)); + if (ret) + goto out_destroy; + kernfs_activate(kn); ret = 0; @@ -602,7 +713,7 @@ out_unlock: static int rdtgroup_rmdir(struct kernfs_node *kn) { struct rdtgroup *rdtgrp; - int ret = 0; + int cpu, ret = 0; rdtgrp = rdtgroup_kn_lock_live(kn); if (!rdtgrp) { @@ -610,6 +721,12 @@ static int rdtgroup_rmdir(struct kernfs_node *kn) return -ENOENT; } + /* Give any CPUs back to the default group */ + cpumask_or(&rdtgroup_default.cpu_mask, + &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask); + for_each_cpu(cpu, &rdtgrp->cpu_mask) + per_cpu(cpu_closid, cpu) = 0; + rdtgrp->flags = RDT_DELETED; closid_free(rdtgrp->closid); list_del(&rdtgrp->rdtgroup_list); @@ -633,6 +750,8 @@ static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = { static int __init rdtgroup_setup_root(void) { + int ret; + rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops, KERNFS_ROOT_CREATE_DEACTIVATED, &rdtgroup_default); @@ -644,12 +763,20 @@ static int __init rdtgroup_setup_root(void) rdtgroup_default.closid = 0; list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups); + ret = rdtgroup_add_files(rdt_root->kn, rdtgroup_base_files, + ARRAY_SIZE(rdtgroup_base_files)); + if (ret) { + kernfs_destroy_root(rdt_root); + goto out; + } + rdtgroup_default.kn = rdt_root->kn; kernfs_activate(rdtgroup_default.kn); +out: mutex_unlock(&rdtgroup_mutex); - return 0; + return ret; } /* |