Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 cache quality monitoring update from Thomas Gleixner:
 "This update provides a complete rewrite of the Cache Quality
  Monitoring (CQM) facility.

  The existing CQM support was duct taped into perf with a lot of issues
  and the attempts to fix those turned out to be incomplete and
  horrible.

  After lengthy discussions it was decided to integrate the CQM support
  into the Resource Director Technology (RDT) facility, which is the
  obvious choise as in hardware CQM is part of RDT. This allowed to add
  Memory Bandwidth Monitoring support on top.

  As a result the mechanisms for allocating cache/memory bandwidth and
  the corresponding monitoring mechanisms are integrated into a single
  management facility with a consistent user interface"

* 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (37 commits)
  x86/intel_rdt: Turn off most RDT features on Skylake
  x86/intel_rdt: Add command line options for resource director technology
  x86/intel_rdt: Move special case code for Haswell to a quirk function
  x86/intel_rdt: Remove redundant ternary operator on return
  x86/intel_rdt/cqm: Improve limbo list processing
  x86/intel_rdt/mbm: Fix MBM overflow handler during CPU hotplug
  x86/intel_rdt: Modify the intel_pqr_state for better performance
  x86/intel_rdt/cqm: Clear the default RMID during hotcpu
  x86/intel_rdt: Show bitmask of shareable resource with other executing units
  x86/intel_rdt/mbm: Handle counter overflow
  x86/intel_rdt/mbm: Add mbm counter initialization
  x86/intel_rdt/mbm: Basic counting of MBM events (total and local)
  x86/intel_rdt/cqm: Add CPU hotplug support
  x86/intel_rdt/cqm: Add sched_in support
  x86/intel_rdt: Introduce rdt_enable_key for scheduling
  x86/intel_rdt/cqm: Add mount,umount support
  x86/intel_rdt/cqm: Add rmdir support
  x86/intel_rdt: Separate the ctrl bits from rmdir
  x86/intel_rdt/cqm: Add mon_data
  x86/intel_rdt: Prepare for RDT monitor data support
  ...

1 files changed, 341 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
new file mode 100644
index 000000000000..f6ea94f8954a
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -0,0 +1,341 @@
+/*
+ * 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)
+		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;
+}
+
+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);
+	}
+	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;
+	}
+
+	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) {
+			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;
+
+	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 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;
+}