Commit 5ff193fb authored by Fenghua Yu's avatar Fenghua Yu Committed by Thomas Gleixner

x86/intel_rdt: Add basic resctrl filesystem support

Use kernfs as basis for our user interface filesystem. This patch
supports mount/umount, and one mount parameter "cdp" to enable code/data
prioritization (though all we do at this point is ensure that the system
can support CDP).  The file system is not populated yet in this patch.

[ tglx: Fixed up a few nits and added cdp handling in case of error ]
Signed-off-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-4-git-send-email-fenghua.yu@intel.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 2264d9c7
#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,
......
......@@ -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/
......
......@@ -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);
......
/*
* 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;
}
......@@ -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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