x86/intel_rdt: Add basic resctrl filesystem support (5ff193fb) · Commits · 戴 / test

arch/x86/include/asm/intel_rdt.h

+26 −0

Original line number	Diff line number	Diff line
		#ifndef _ASM_X86_INTEL_RDT_H
		#define _ASM_X86_INTEL_RDT_H

		#include <linux/jump_label.h>

		#define IA32_L3_QOS_CFG 0xc81
		#define IA32_L3_CBM_BASE 0xc90
		#define IA32_L2_CBM_BASE 0xd10

		#define L3_QOS_CDP_ENABLE 0x01ULL

		/**
		* struct rdtgroup - store rdtgroup's data in resctrl file system.
		* @kn: kernfs node
		* @rdtgroup_list: linked list for all rdtgroups
		* @closid: closid for this rdtgroup
		*/
		struct rdtgroup {
		struct kernfs_node *kn;
		struct list_head rdtgroup_list;
		int closid;
		};

		/* List of all resource groups */
		extern struct list_head rdt_all_groups;

		int __init rdtgroup_init(void);

		/**
		* struct rdt_resource - attributes of an RDT resource
		* @enabled: Is this feature enabled on this machine
		@@ -68,6 +90,10 @@ struct msr_param {
		extern struct mutex rdtgroup_mutex;

		extern struct rdt_resource rdt_resources_all[];
		extern struct rdtgroup rdtgroup_default;
		DECLARE_STATIC_KEY_FALSE(rdt_enable_key);

		int __init rdtgroup_init(void);

		enum {
		RDT_RESOURCE_L3,

arch/x86/kernel/cpu/Makefile

+1 −1

Original line number	Diff line number	Diff line
		@@ -34,7 +34,7 @@ obj-$(CONFIG_CPU_SUP_CENTAUR) += centaur.o
		obj-$(CONFIG_CPU_SUP_TRANSMETA_32) += transmeta.o
		obj-$(CONFIG_CPU_SUP_UMC_32) += umc.o

		obj-$(CONFIG_INTEL_RDT_A) += intel_rdt.o
		obj-$(CONFIG_INTEL_RDT_A) += intel_rdt.o intel_rdt_rdtgroup.o

		obj-$(CONFIG_X86_MCE) += mcheck/
		obj-$(CONFIG_MTRR) += mtrr/

arch/x86/kernel/cpu/intel_rdt.c

+7 −1

Original line number	Diff line number	Diff line
		@@ -361,7 +361,7 @@ static int intel_rdt_offline_cpu(unsigned int cpu)
		static int __init intel_rdt_late_init(void)
		{
		struct rdt_resource *r;
		int state;
		int state, ret;

		if (!get_rdt_resources())
		return -ENODEV;
		@@ -372,6 +372,12 @@ static int __init intel_rdt_late_init(void)
		if (state < 0)
		return state;

		ret = rdtgroup_init();
		if (ret) {
		cpuhp_remove_state(state);
		return ret;
		}

		for_each_capable_rdt_resource(r)
		pr_info("Intel RDT %s allocation detected\n", r->name);

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

0 → 100644

+271 −0

Original line number	Diff line number	Diff line
		/*
		* User interface for Resource Alloction in Resource Director Technology(RDT)
		*
		* Copyright (C) 2016 Intel Corporation
		*
		* Author: Fenghua Yu <fenghua.yu@intel.com>
		*
		* This program is free software; you can redistribute it and/or modify it
		* under the terms and conditions of the GNU General Public License,
		* version 2, as published by the Free Software Foundation.
		*
		* This program is distributed in the hope it will be useful, but WITHOUT
		* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
		* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
		* more details.
		*
		* More information about RDT be found in the Intel (R) x86 Architecture
		* Software Developer Manual.
		*/

		#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

		#include <linux/fs.h>
		#include <linux/sysfs.h>
		#include <linux/kernfs.h>
		#include <linux/slab.h>

		#include <uapi/linux/magic.h>

		#include <asm/intel_rdt.h>

		DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
		struct kernfs_root *rdt_root;
		struct rdtgroup rdtgroup_default;
		LIST_HEAD(rdt_all_groups);

		static void l3_qos_cfg_update(void *arg)
		{
		bool *enable = arg;

		wrmsrl(IA32_L3_QOS_CFG, *enable ? L3_QOS_CDP_ENABLE : 0ULL);
		}

		static int set_l3_qos_cfg(struct rdt_resource *r, bool enable)
		{
		cpumask_var_t cpu_mask;
		struct rdt_domain *d;
		int cpu;

		if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
		return -ENOMEM;

		list_for_each_entry(d, &r->domains, list) {
		/* Pick one CPU from each domain instance to update MSR */
		cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
		}
		cpu = get_cpu();
		/* Update QOS_CFG MSR on this cpu if it's in cpu_mask. */
		if (cpumask_test_cpu(cpu, cpu_mask))
		l3_qos_cfg_update(&enable);
		/* Update QOS_CFG MSR on all other cpus in cpu_mask. */
		smp_call_function_many(cpu_mask, l3_qos_cfg_update, &enable, 1);
		put_cpu();

		free_cpumask_var(cpu_mask);

		return 0;
		}

		static int cdp_enable(void)
		{
		struct rdt_resource *r_l3data = &rdt_resources_all[RDT_RESOURCE_L3DATA];
		struct rdt_resource *r_l3code = &rdt_resources_all[RDT_RESOURCE_L3CODE];
		struct rdt_resource *r_l3 = &rdt_resources_all[RDT_RESOURCE_L3];
		int ret;

		if (!r_l3->capable \|\| !r_l3data->capable \|\| !r_l3code->capable)
		return -EINVAL;

		ret = set_l3_qos_cfg(r_l3, true);
		if (!ret) {
		r_l3->enabled = false;
		r_l3data->enabled = true;
		r_l3code->enabled = true;
		}
		return ret;
		}

		static void cdp_disable(void)
		{
		struct rdt_resource *r = &rdt_resources_all[RDT_RESOURCE_L3];

		r->enabled = r->capable;

		if (rdt_resources_all[RDT_RESOURCE_L3DATA].enabled) {
		rdt_resources_all[RDT_RESOURCE_L3DATA].enabled = false;
		rdt_resources_all[RDT_RESOURCE_L3CODE].enabled = false;
		set_l3_qos_cfg(r, false);
		}
		}

		static int parse_rdtgroupfs_options(char *data)
		{
		char token, o = data;
		int ret = 0;

		while ((token = strsep(&o, ",")) != NULL) {
		if (!*token)
		return -EINVAL;

		if (!strcmp(token, "cdp"))
		ret = cdp_enable();
		}

		return ret;
		}

		static struct dentry rdt_mount(struct file_system_type fs_type,
		int flags, const char *unused_dev_name,
		void *data)
		{
		struct dentry *dentry;
		int ret;

		mutex_lock(&rdtgroup_mutex);
		/*
		* resctrl file system can only be mounted once.
		*/
		if (static_branch_unlikely(&rdt_enable_key)) {
		dentry = ERR_PTR(-EBUSY);
		goto out;
		}

		ret = parse_rdtgroupfs_options(data);
		if (ret) {
		dentry = ERR_PTR(ret);
		goto out_cdp;
		}

		dentry = kernfs_mount(fs_type, flags, rdt_root,
		RDTGROUP_SUPER_MAGIC, NULL);
		if (IS_ERR(dentry))
		goto out_cdp;

		static_branch_enable(&rdt_enable_key);
		goto out;

		out_cdp:
		cdp_disable();
		out:
		mutex_unlock(&rdtgroup_mutex);

		return dentry;
		}

		static int reset_all_cbms(struct rdt_resource *r)
		{
		struct msr_param msr_param;
		cpumask_var_t cpu_mask;
		struct rdt_domain *d;
		int i, cpu;

		if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
		return -ENOMEM;

		msr_param.res = r;
		msr_param.low = 0;
		msr_param.high = r->num_closid;

		/*
		* Disable resource control for this resource by setting all
		* CBMs in all domains to the maximum mask value. Pick one CPU
		* from each domain to update the MSRs below.
		*/
		list_for_each_entry(d, &r->domains, list) {
		cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);

		for (i = 0; i < r->num_closid; i++)
		d->cbm[i] = r->max_cbm;
		}
		cpu = get_cpu();
		/* Update CBM on this cpu if it's in cpu_mask. */
		if (cpumask_test_cpu(cpu, cpu_mask))
		rdt_cbm_update(&msr_param);
		/* Update CBM on all other cpus in cpu_mask. */
		smp_call_function_many(cpu_mask, rdt_cbm_update, &msr_param, 1);
		put_cpu();

		free_cpumask_var(cpu_mask);

		return 0;
		}

		static void rdt_kill_sb(struct super_block *sb)
		{
		struct rdt_resource *r;

		mutex_lock(&rdtgroup_mutex);

		/Put everything back to default values. /
		for_each_enabled_rdt_resource(r)
		reset_all_cbms(r);
		cdp_disable();
		static_branch_disable(&rdt_enable_key);
		kernfs_kill_sb(sb);
		mutex_unlock(&rdtgroup_mutex);
		}

		static struct file_system_type rdt_fs_type = {
		.name = "resctrl",
		.mount = rdt_mount,
		.kill_sb = rdt_kill_sb,
		};

		static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
		};

		static int __init rdtgroup_setup_root(void)
		{
		rdt_root = kernfs_create_root(&rdtgroup_kf_syscall_ops,
		KERNFS_ROOT_CREATE_DEACTIVATED,
		&rdtgroup_default);
		if (IS_ERR(rdt_root))
		return PTR_ERR(rdt_root);

		mutex_lock(&rdtgroup_mutex);

		rdtgroup_default.closid = 0;
		list_add(&rdtgroup_default.rdtgroup_list, &rdt_all_groups);

		rdtgroup_default.kn = rdt_root->kn;
		kernfs_activate(rdtgroup_default.kn);

		mutex_unlock(&rdtgroup_mutex);

		return 0;
		}

		/*
		* rdtgroup_init - rdtgroup initialization
		*
		* Setup resctrl file system including set up root, create mount point,
		* register rdtgroup filesystem, and initialize files under root directory.
		*
		* Return: 0 on success or -errno
		*/
		int __init rdtgroup_init(void)
		{
		int ret = 0;

		ret = rdtgroup_setup_root();
		if (ret)
		return ret;

		ret = sysfs_create_mount_point(fs_kobj, "resctrl");
		if (ret)
		goto cleanup_root;

		ret = register_filesystem(&rdt_fs_type);
		if (ret)
		goto cleanup_mountpoint;

		return 0;

		cleanup_mountpoint:
		sysfs_remove_mount_point(fs_kobj, "resctrl");
		cleanup_root:
		kernfs_destroy_root(rdt_root);

		return ret;
		}

include/uapi/linux/magic.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -57,6 +57,7 @@
		#define CGROUP_SUPER_MAGIC 0x27e0eb
		#define CGROUP2_SUPER_MAGIC 0x63677270

		#define RDTGROUP_SUPER_MAGIC 0x7655821

		#define STACK_END_MAGIC 0x57AC6E9D

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