[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / cpu / intel_rdt_schemata.c

/*
 * Resource Director Technology(RDT)
 * - Cache Allocation code.
 *
 * Copyright (C) 2016 Intel Corporation
 *
 * Authors:
 *    Fenghua Yu <fenghua.yu@intel.com>
 *    Tony Luck <tony.luck@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 June 2016, volume 3, section 17.17.
 */

#define pr_fmt(fmt)	KBUILD_MODNAME ": " fmt

#include <linux/kernfs.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <asm/intel_rdt.h>

/*
 * Check whether MBA bandwidth percentage value is correct. The value is
 * checked against the minimum and max bandwidth values specified by the
 * hardware. The allocated bandwidth percentage is rounded to the next
 * control step available on the hardware.
 */
static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
{
	unsigned long bw;
	int ret;

	/*
	 * Only linear delay values is supported for current Intel SKUs.
	 */
	if (!r->membw.delay_linear)
		return false;

	ret = kstrtoul(buf, 10, &bw);
	if (ret)
		return false;

	if (bw < r->membw.min_bw || bw > r->default_ctrl)
		return false;

	*data = roundup(bw, (unsigned long)r->membw.bw_gran);
	return true;
}

int parse_bw(char *buf, struct rdt_resource *r, struct rdt_domain *d)
{
	unsigned long data;

	if (d->have_new_ctrl)
		return -EINVAL;

	if (!bw_validate(buf, &data, r))
		return -EINVAL;
	d->new_ctrl = data;
	d->have_new_ctrl = true;

	return 0;
}

/*
 * Check whether a cache bit mask is valid. The SDM says:
 *	Please note that all (and only) contiguous '1' combinations
 *	are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
 * Additionally Haswell requires at least two bits set.
 */
static bool cbm_validate(char *buf, unsigned long *data, struct rdt_resource *r)
{
	unsigned long first_bit, zero_bit, val;
	unsigned int cbm_len = r->cache.cbm_len;
	int ret;

	ret = kstrtoul(buf, 16, &val);
	if (ret)
		return false;

	if (val == 0 || val > r->default_ctrl)
		return false;

	first_bit = find_first_bit(&val, cbm_len);
	zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);

	if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)
		return false;

	if ((zero_bit - first_bit) < r->cache.min_cbm_bits)
		return false;

	*data = val;
	return true;
}

/*
 * Read one cache bit mask (hex). Check that it is valid for the current
 * resource type.
 */
int parse_cbm(char *buf, struct rdt_resource *r, struct rdt_domain *d)
{
	unsigned long data;

	if (d->have_new_ctrl)
		return -EINVAL;

	if(!cbm_validate(buf, &data, r))
		return -EINVAL;
	d->new_ctrl = data;
	d->have_new_ctrl = true;

	return 0;
}

/*
 * For each domain in this resource we expect to find a series of:
 *	id=mask
 * separated by ";". The "id" is in decimal, and must match one of
 * the "id"s for this resource.
 */
static int parse_line(char *line, struct rdt_resource *r)
{
	char *dom = NULL, *id;
	struct rdt_domain *d;
	unsigned long dom_id;

next:
	if (!line || line[0] == '\0')
		return 0;
	dom = strsep(&line, ";");
	id = strsep(&dom, "=");
	if (!dom || kstrtoul(id, 10, &dom_id))
		return -EINVAL;
	dom = strim(dom);
	list_for_each_entry(d, &r->domains, list) {
		if (d->id == dom_id) {
			if (r->parse_ctrlval(dom, r, d))
				return -EINVAL;
			goto next;
		}
	}
	return -EINVAL;
}

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

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

	msr_param.low = closid;
	msr_param.high = msr_param.low + 1;
	msr_param.res = r;

	list_for_each_entry(d, &r->domains, list) {
		if (d->have_new_ctrl && d->new_ctrl != d->ctrl_val[closid]) {
			cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
			d->ctrl_val[closid] = d->new_ctrl;
		}
	}
	if (cpumask_empty(cpu_mask))
		goto done;
	cpu = get_cpu();
	/* Update CBM on this cpu if it's in cpu_mask. */
	if (cpumask_test_cpu(cpu, cpu_mask))
		rdt_ctrl_update(&msr_param);
	/* Update CBM on other cpus. */
	smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
	put_cpu();

done:
	free_cpumask_var(cpu_mask);

	return 0;
}

ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
				char *buf, size_t nbytes, loff_t off)
{
	struct rdtgroup *rdtgrp;
	struct rdt_domain *dom;
	struct rdt_resource *r;
	char *tok, *resname;
	int closid, ret = 0;

	/* Valid input requires a trailing newline */
	if (nbytes == 0 || buf[nbytes - 1] != '\n')
		return -EINVAL;
	buf[nbytes - 1] = '\0';

	rdtgrp = rdtgroup_kn_lock_live(of->kn);
	if (!rdtgrp) {
		rdtgroup_kn_unlock(of->kn);
		return -ENOENT;
	}

	closid = rdtgrp->closid;

	for_each_enabled_rdt_resource(r)
		list_for_each_entry(dom, &r->domains, list)
			dom->have_new_ctrl = false;

	while ((tok = strsep(&buf, "\n")) != NULL) {
		resname = strim(strsep(&tok, ":"));
		if (!tok) {
			ret = -EINVAL;
			goto out;
		}
		for_each_enabled_rdt_resource(r) {
			if (!strcmp(resname, r->name) &&
			    closid < r->num_closid) {
				ret = parse_line(tok, r);
				if (ret)
					goto out;
				break;
			}
		}
		if (!r->name) {
			ret = -EINVAL;
			goto out;
		}
	}

	for_each_enabled_rdt_resource(r) {
		ret = update_domains(r, closid);
		if (ret)
			goto out;
	}

out:
	rdtgroup_kn_unlock(of->kn);
	return ret ?: nbytes;
}

static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
{
	struct rdt_domain *dom;
	bool sep = false;

	seq_printf(s, "%*s:", max_name_width, r->name);
	list_for_each_entry(dom, &r->domains, list) {
		if (sep)
			seq_puts(s, ";");
		seq_printf(s, r->format_str, dom->id, max_data_width,
			   dom->ctrl_val[closid]);
		sep = true;
	}
	seq_puts(s, "\n");
}

int rdtgroup_schemata_show(struct kernfs_open_file *of,
			   struct seq_file *s, void *v)
{
	struct rdtgroup *rdtgrp;
	struct rdt_resource *r;
	int closid, ret = 0;

	rdtgrp = rdtgroup_kn_lock_live(of->kn);
	if (rdtgrp) {
		closid = rdtgrp->closid;
		for_each_enabled_rdt_resource(r) {
			if (closid < r->num_closid)
				show_doms(s, r, closid);
		}
	} else {
		ret = -ENOENT;
	}
	rdtgroup_kn_unlock(of->kn);
	return ret;
}
Commit	Line	Data
60ec2440 TL	1	/*
	2	* Resource Director Technology(RDT)
	3	* - Cache Allocation code.
	4	*
	5	* Copyright (C) 2016 Intel Corporation
	6	*
	7	* Authors:
	8	* Fenghua Yu <fenghua.yu@intel.com>
	9	* Tony Luck <tony.luck@intel.com>
	10	*
	11	* This program is free software; you can redistribute it and/or modify it
	12	* under the terms and conditions of the GNU General Public License,
	13	* version 2, as published by the Free Software Foundation.
	14	*
	15	* This program is distributed in the hope it will be useful, but WITHOUT
	16	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	17	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	18	* more details.
	19	*
	20	* More information about RDT be found in the Intel (R) x86 Architecture
	21	* Software Developer Manual June 2016, volume 3, section 17.17.
	22	*/
	23
	24	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
	25
	26	#include <linux/kernfs.h>
	27	#include <linux/seq_file.h>
	28	#include <linux/slab.h>
	29	#include <asm/intel_rdt.h>
	30
64e8ed3d VS	31	/*
	32	* Check whether MBA bandwidth percentage value is correct. The value is
	33	* checked against the minimum and max bandwidth values specified by the
	34	* hardware. The allocated bandwidth percentage is rounded to the next
	35	* control step available on the hardware.
	36	*/
	37	static bool bw_validate(char buf, unsigned long data, struct rdt_resource *r)
	38	{
	39	unsigned long bw;
	40	int ret;
	41
	42	/*
	43	* Only linear delay values is supported for current Intel SKUs.
	44	*/
	45	if (!r->membw.delay_linear)
	46	return false;
	47
	48	ret = kstrtoul(buf, 10, &bw);
	49	if (ret)
	50	return false;
	51
	52	if (bw < r->membw.min_bw \|\| bw > r->default_ctrl)
	53	return false;
	54
	55	*data = roundup(bw, (unsigned long)r->membw.bw_gran);
	56	return true;
	57	}
	58
	59	int parse_bw(char buf, struct rdt_resource r, struct rdt_domain *d)
	60	{
	61	unsigned long data;
	62
	63	if (d->have_new_ctrl)
	64	return -EINVAL;
	65
	66	if (!bw_validate(buf, &data, r))
	67	return -EINVAL;
	68	d->new_ctrl = data;
	69	d->have_new_ctrl = true;
	70
	71	return 0;
	72	}
	73
60ec2440 TL	74	/*
	75	* Check whether a cache bit mask is valid. The SDM says:
	76	* Please note that all (and only) contiguous '1' combinations
	77	* are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
	78	* Additionally Haswell requires at least two bits set.
	79	*/
c6ea67de	80	static bool cbm_validate(char buf, unsigned long data, struct rdt_resource *r)
60ec2440	81	{
c6ea67de	82	unsigned long first_bit, zero_bit, val;
d3e11b4d	83	unsigned int cbm_len = r->cache.cbm_len;
c6ea67de VS	84	int ret;
	85
	86	ret = kstrtoul(buf, 16, &val);
	87	if (ret)
	88	return false;
60ec2440	89
c6ea67de	90	if (val == 0 \|\| val > r->default_ctrl)
60ec2440 TL	91	return false;
60ec2440 TL	92
c6ea67de VS	93	first_bit = find_first_bit(&val, cbm_len);
c6ea67de VS	94	zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
60ec2440	95
c6ea67de	96	if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len)
60ec2440 TL	97	return false;
60ec2440 TL	98
d3e11b4d	99	if ((zero_bit - first_bit) < r->cache.min_cbm_bits)
60ec2440	100	return false;
c6ea67de VS	101
c6ea67de VS	102	*data = val;
60ec2440 TL	103	return true;
	104	}
	105
	106	/*
	107	* Read one cache bit mask (hex). Check that it is valid for the current
	108	* resource type.
	109	*/
c6ea67de	110	int parse_cbm(char buf, struct rdt_resource r, struct rdt_domain *d)
60ec2440 TL	111	{
60ec2440 TL	112	unsigned long data;
60ec2440	113
2545e9f5	114	if (d->have_new_ctrl)
c4026b7b TL	115	return -EINVAL;
c4026b7b TL	116
c6ea67de	117	if(!cbm_validate(buf, &data, r))
60ec2440	118	return -EINVAL;
2545e9f5 VS	119	d->new_ctrl = data;
2545e9f5 VS	120	d->have_new_ctrl = true;
60ec2440 TL	121
	122	return 0;
	123	}
	124
	125	/*
	126	* For each domain in this resource we expect to find a series of:
	127	* id=mask
c4026b7b TL	128	* separated by ";". The "id" is in decimal, and must match one of
c4026b7b TL	129	* the "id"s for this resource.
60ec2440 TL	130	*/
	131	static int parse_line(char line, struct rdt_resource r)
	132	{
	133	char dom = NULL, id;
	134	struct rdt_domain *d;
	135	unsigned long dom_id;
	136
c4026b7b TL	137	next:
	138	if (!line \|\| line[0] == '\0')
	139	return 0;
	140	dom = strsep(&line, ";");
	141	id = strsep(&dom, "=");
	142	if (!dom \|\| kstrtoul(id, 10, &dom_id))
	143	return -EINVAL;
634b0e04	144	dom = strim(dom);
60ec2440	145	list_for_each_entry(d, &r->domains, list) {
c4026b7b	146	if (d->id == dom_id) {
c6ea67de	147	if (r->parse_ctrlval(dom, r, d))
c4026b7b TL	148	return -EINVAL;
	149	goto next;
	150	}
60ec2440	151	}
c4026b7b	152	return -EINVAL;
60ec2440 TL	153	}
	154
	155	static int update_domains(struct rdt_resource *r, int closid)
	156	{
	157	struct msr_param msr_param;
	158	cpumask_var_t cpu_mask;
	159	struct rdt_domain *d;
c4026b7b	160	int cpu;
60ec2440 TL	161
	162	if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
	163	return -ENOMEM;
	164
	165	msr_param.low = closid;
	166	msr_param.high = msr_param.low + 1;
	167	msr_param.res = r;
	168
	169	list_for_each_entry(d, &r->domains, list) {
2545e9f5	170	if (d->have_new_ctrl && d->new_ctrl != d->ctrl_val[closid]) {
c4026b7b	171	cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
2545e9f5	172	d->ctrl_val[closid] = d->new_ctrl;
c4026b7b	173	}
60ec2440	174	}
c4026b7b TL	175	if (cpumask_empty(cpu_mask))
c4026b7b TL	176	goto done;
60ec2440 TL	177	cpu = get_cpu();
	178	/* Update CBM on this cpu if it's in cpu_mask. */
	179	if (cpumask_test_cpu(cpu, cpu_mask))
2545e9f5	180	rdt_ctrl_update(&msr_param);
60ec2440	181	/* Update CBM on other cpus. */
2545e9f5	182	smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
60ec2440 TL	183	put_cpu();
60ec2440 TL	184
c4026b7b	185	done:
60ec2440 TL	186	free_cpumask_var(cpu_mask);
	187
	188	return 0;
	189	}
	190
	191	ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
	192	char *buf, size_t nbytes, loff_t off)
	193	{
	194	struct rdtgroup *rdtgrp;
c4026b7b	195	struct rdt_domain *dom;
60ec2440 TL	196	struct rdt_resource *r;
	197	char tok, resname;
	198	int closid, ret = 0;
60ec2440 TL	199
	200	/* Valid input requires a trailing newline */
	201	if (nbytes == 0 \|\| buf[nbytes - 1] != '\n')
	202	return -EINVAL;
	203	buf[nbytes - 1] = '\0';
	204
	205	rdtgrp = rdtgroup_kn_lock_live(of->kn);
	206	if (!rdtgrp) {
	207	rdtgroup_kn_unlock(of->kn);
	208	return -ENOENT;
	209	}
	210
	211	closid = rdtgrp->closid;
	212
c4026b7b TL	213	for_each_enabled_rdt_resource(r)
c4026b7b TL	214	list_for_each_entry(dom, &r->domains, list)
2545e9f5	215	dom->have_new_ctrl = false;
60ec2440 TL	216
60ec2440 TL	217	while ((tok = strsep(&buf, "\n")) != NULL) {
634b0e04	218	resname = strim(strsep(&tok, ":"));
60ec2440 TL	219	if (!tok) {
	220	ret = -EINVAL;
	221	goto out;
	222	}
	223	for_each_enabled_rdt_resource(r) {
	224	if (!strcmp(resname, r->name) &&
	225	closid < r->num_closid) {
	226	ret = parse_line(tok, r);
	227	if (ret)
	228	goto out;
	229	break;
	230	}
	231	}
	232	if (!r->name) {
	233	ret = -EINVAL;
	234	goto out;
	235	}
	236	}
	237
60ec2440 TL	238	for_each_enabled_rdt_resource(r) {
	239	ret = update_domains(r, closid);
	240	if (ret)
	241	goto out;
	242	}
	243
	244	out:
	245	rdtgroup_kn_unlock(of->kn);
60ec2440 TL	246	return ret ?: nbytes;
	247	}
	248
	249	static void show_doms(struct seq_file s, struct rdt_resource r, int closid)
	250	{
	251	struct rdt_domain *dom;
	252	bool sep = false;
	253
de016df8	254	seq_printf(s, "%*s:", max_name_width, r->name);
60ec2440 TL	255	list_for_each_entry(dom, &r->domains, list) {
	256	if (sep)
	257	seq_puts(s, ";");
c6ea67de	258	seq_printf(s, r->format_str, dom->id, max_data_width,
2545e9f5	259	dom->ctrl_val[closid]);
60ec2440 TL	260	sep = true;
	261	}
	262	seq_puts(s, "\n");
	263	}
	264
	265	int rdtgroup_schemata_show(struct kernfs_open_file *of,
	266	struct seq_file s, void v)
	267	{
	268	struct rdtgroup *rdtgrp;
	269	struct rdt_resource *r;
	270	int closid, ret = 0;
	271
	272	rdtgrp = rdtgroup_kn_lock_live(of->kn);
	273	if (rdtgrp) {
	274	closid = rdtgrp->closid;
	275	for_each_enabled_rdt_resource(r) {
	276	if (closid < r->num_closid)
	277	show_doms(s, r, closid);
	278	}
	279	} else {
	280	ret = -ENOENT;
	281	}
	282	rdtgroup_kn_unlock(of->kn);
	283	return ret;
	284	}