arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c - third_party/linux - Git at Google

 /*
  * 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 "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) {
 		rdt_last_cmd_puts("No support for non-linear MB domains\n");
 		return false;
 	}

 	ret = kstrtoul(buf, 10, &bw);
 	if (ret) {
 		rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
 		return false;
 	}

 	if ((bw < r->membw.min_bw || bw > r->default_ctrl) &&
 	    !is_mba_sc(r)) {
 		rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
 				    r->membw.min_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) {
 		rdt_last_cmd_printf("duplicate domain %d\n", d->id);
 		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) {
 		rdt_last_cmd_printf("non-hex character in mask %s\n", buf);
 		return false;
 	}

 	if (val == 0 || val > r->default_ctrl) {
 		rdt_last_cmd_puts("mask out of range\n");
 		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) {
 		rdt_last_cmd_printf("mask %lx has non-consecutive 1-bits\n", val);
 		return false;
 	}

 	if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
 		rdt_last_cmd_printf("Need at least %d bits in mask\n",
 				    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) {
 		rdt_last_cmd_printf("duplicate domain %d\n", d->id);
 		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)) {
 		rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
 		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;
 	bool mba_sc;
 	u32 *dc;
 	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;

 	mba_sc = is_mba_sc(r);
 	list_for_each_entry(d, &r->domains, list) {
 		dc = !mba_sc ? d->ctrl_val : d->mbps_val;
 		if (d->have_new_ctrl && d->new_ctrl != dc[closid]) {
 			cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
 			dc[closid] = d->new_ctrl;
 		}
 	}

 	/*
 	 * Avoid writing the control msr with control values when
 	 * MBA software controller is enabled
 	 */
 	if (cpumask_empty(cpu_mask) || mba_sc)
 		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;
 }

 static int rdtgroup_parse_resource(char *resname, char *tok, int closid)
 {
 	struct rdt_resource *r;

 	for_each_alloc_enabled_rdt_resource(r) {
 		if (!strcmp(resname, r->name) && closid < r->num_closid)
 			return parse_line(tok, r);
 	}
 	rdt_last_cmd_printf("unknown/unsupported resource name '%s'\n", resname);
 	return -EINVAL;
 }

 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;
 	}
 	rdt_last_cmd_clear();

 	closid = rdtgrp->closid;

 	for_each_alloc_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) {
 			rdt_last_cmd_puts("Missing ':'\n");
 			ret = -EINVAL;
 			goto out;
 		}
 		if (tok[0] == '\0') {
 			rdt_last_cmd_printf("Missing '%s' value\n", resname);
 			ret = -EINVAL;
 			goto out;
 		}
 		ret = rdtgroup_parse_resource(resname, tok, closid);
 		if (ret)
 			goto out;
 	}

 	for_each_alloc_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;
 	u32 ctrl_val;

 	seq_printf(s, "%*s:", max_name_width, r->name);
 	list_for_each_entry(dom, &r->domains, list) {
 		if (sep)
 			seq_puts(s, ";");

 		ctrl_val = (!is_mba_sc(r) ? dom->ctrl_val[closid] :
 			    dom->mbps_val[closid]);
 		seq_printf(s, r->format_str, dom->id, max_data_width,
 			   ctrl_val);
 		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 ret = 0;
 	u32 closid;

 	rdtgrp = rdtgroup_kn_lock_live(of->kn);
 	if (rdtgrp) {
 		closid = rdtgrp->closid;
 		for_each_alloc_enabled_rdt_resource(r) {
 			if (closid < r->num_closid)
 				show_doms(s, r, closid);
 		}
 	} else {
 		ret = -ENOENT;
 	}
 	rdtgroup_kn_unlock(of->kn);
 	return ret;
 }

 void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
 		    struct rdtgroup *rdtgrp, int evtid, int first)
 {
 	/*
 	 * setup the parameters to send to the IPI to read the data.
 	 */
 	rr->rgrp = rdtgrp;
 	rr->evtid = evtid;
 	rr->d = d;
 	rr->val = 0;
 	rr->first = first;

 	smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
 }

 int rdtgroup_mondata_show(struct seq_file *m, void *arg)
 {
 	struct kernfs_open_file *of = m->private;
 	u32 resid, evtid, domid;
 	struct rdtgroup *rdtgrp;
 	struct rdt_resource *r;
 	union mon_data_bits md;
 	struct rdt_domain *d;
 	struct rmid_read rr;
 	int ret = 0;

 	rdtgrp = rdtgroup_kn_lock_live(of->kn);

 	md.priv = of->kn->priv;
 	resid = md.u.rid;
 	domid = md.u.domid;
 	evtid = md.u.evtid;

 	r = &rdt_resources_all[resid];
 	d = rdt_find_domain(r, domid, NULL);
 	if (!d) {
 		ret = -ENOENT;
 		goto out;
 	}

 	mon_event_read(&rr, d, rdtgrp, evtid, false);

 	if (rr.val & RMID_VAL_ERROR)
 		seq_puts(m, "Error\n");
 	else if (rr.val & RMID_VAL_UNAVAIL)
 		seq_puts(m, "Unavailable\n");
 	else
 		seq_printf(m, "%llu\n", rr.val * r->mon_scale);

 out:
 	rdtgroup_kn_unlock(of->kn);
 	return ret;
 }
	/*
	* 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 "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) {
	rdt_last_cmd_puts("No support for non-linear MB domains\n");
	return false;
	}

	ret = kstrtoul(buf, 10, &bw);
	if (ret) {
	rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
	return false;
	}

	if ((bw < r->membw.min_bw \|\| bw > r->default_ctrl) &&
	!is_mba_sc(r)) {
	rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
	r->membw.min_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) {
	rdt_last_cmd_printf("duplicate domain %d\n", d->id);
	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) {
	rdt_last_cmd_printf("non-hex character in mask %s\n", buf);
	return false;
	}

	if (val == 0 \|\| val > r->default_ctrl) {
	rdt_last_cmd_puts("mask out of range\n");
	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) {
	rdt_last_cmd_printf("mask %lx has non-consecutive 1-bits\n", val);
	return false;
	}

	if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
	rdt_last_cmd_printf("Need at least %d bits in mask\n",
	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) {
	rdt_last_cmd_printf("duplicate domain %d\n", d->id);
	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)) {
	rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
	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;
	bool mba_sc;
	u32 *dc;
	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;

	mba_sc = is_mba_sc(r);
	list_for_each_entry(d, &r->domains, list) {
	dc = !mba_sc ? d->ctrl_val : d->mbps_val;
	if (d->have_new_ctrl && d->new_ctrl != dc[closid]) {
	cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
	dc[closid] = d->new_ctrl;
	}
	}

	/*
	* Avoid writing the control msr with control values when
	* MBA software controller is enabled
	*/
	if (cpumask_empty(cpu_mask) \|\| mba_sc)
	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;
	}

	static int rdtgroup_parse_resource(char resname, char tok, int closid)
	{
	struct rdt_resource *r;

	for_each_alloc_enabled_rdt_resource(r) {
	if (!strcmp(resname, r->name) && closid < r->num_closid)
	return parse_line(tok, r);
	}
	rdt_last_cmd_printf("unknown/unsupported resource name '%s'\n", resname);
	return -EINVAL;
	}

	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;
	}
	rdt_last_cmd_clear();

	closid = rdtgrp->closid;

	for_each_alloc_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) {
	rdt_last_cmd_puts("Missing ':'\n");
	ret = -EINVAL;
	goto out;
	}
	if (tok[0] == '\0') {
	rdt_last_cmd_printf("Missing '%s' value\n", resname);
	ret = -EINVAL;
	goto out;
	}
	ret = rdtgroup_parse_resource(resname, tok, closid);
	if (ret)
	goto out;
	}

	for_each_alloc_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;
	u32 ctrl_val;

	seq_printf(s, "%*s:", max_name_width, r->name);
	list_for_each_entry(dom, &r->domains, list) {
	if (sep)
	seq_puts(s, ";");

	ctrl_val = (!is_mba_sc(r) ? dom->ctrl_val[closid] :
	dom->mbps_val[closid]);
	seq_printf(s, r->format_str, dom->id, max_data_width,
	ctrl_val);
	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 ret = 0;
	u32 closid;

	rdtgrp = rdtgroup_kn_lock_live(of->kn);
	if (rdtgrp) {
	closid = rdtgrp->closid;
	for_each_alloc_enabled_rdt_resource(r) {
	if (closid < r->num_closid)
	show_doms(s, r, closid);
	}
	} else {
	ret = -ENOENT;
	}
	rdtgroup_kn_unlock(of->kn);
	return ret;
	}

	void mon_event_read(struct rmid_read rr, struct rdt_domain d,
	struct rdtgroup *rdtgrp, int evtid, int first)
	{
	/*
	* setup the parameters to send to the IPI to read the data.
	*/
	rr->rgrp = rdtgrp;
	rr->evtid = evtid;
	rr->d = d;
	rr->val = 0;
	rr->first = first;

	smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
	}

	int rdtgroup_mondata_show(struct seq_file m, void arg)
	{
	struct kernfs_open_file *of = m->private;
	u32 resid, evtid, domid;
	struct rdtgroup *rdtgrp;
	struct rdt_resource *r;
	union mon_data_bits md;
	struct rdt_domain *d;
	struct rmid_read rr;
	int ret = 0;

	rdtgrp = rdtgroup_kn_lock_live(of->kn);

	md.priv = of->kn->priv;
	resid = md.u.rid;
	domid = md.u.domid;
	evtid = md.u.evtid;

	r = &rdt_resources_all[resid];
	d = rdt_find_domain(r, domid, NULL);
	if (!d) {
	ret = -ENOENT;
	goto out;
	}

	mon_event_read(&rr, d, rdtgrp, evtid, false);

	if (rr.val & RMID_VAL_ERROR)
	seq_puts(m, "Error\n");
	else if (rr.val & RMID_VAL_UNAVAIL)
	seq_puts(m, "Unavailable\n");
	else
	seq_printf(m, "%llu\n", rr.val * r->mon_scale);

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