1 files changed, 245 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/intel_rdt_schemata.c b/arch/x86/kernel/cpu/intel_rdt_schemata.c
new file mode 100644
index 000000000000..f369cb8db0d5
--- /dev/null
+++ b/arch/x86/kernel/cpu/intel_rdt_schemata.c
@@ -0,0 +1,245 @@
+/*
+ * 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 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(unsigned long var, struct rdt_resource *r)
+{
+	unsigned long first_bit, zero_bit;
+
+	if (var == 0 || var > r->max_cbm)
+		return false;
+
+	first_bit = find_first_bit(&var, r->cbm_len);
+	zero_bit = find_next_zero_bit(&var, r->cbm_len, first_bit);
+
+	if (find_next_bit(&var, r->cbm_len, zero_bit) < r->cbm_len)
+		return false;
+
+	if ((zero_bit - first_bit) < r->min_cbm_bits)
+		return false;
+	return true;
+}
+
+/*
+ * Read one cache bit mask (hex). Check that it is valid for the current
+ * resource type.
+ */
+static int parse_cbm(char *buf, struct rdt_resource *r)
+{
+	unsigned long data;
+	int ret;
+
+	ret = kstrtoul(buf, 16, &data);
+	if (ret)
+		return ret;
+	if (!cbm_validate(data, r))
+		return -EINVAL;
+	r->tmp_cbms[r->num_tmp_cbms++] = data;
+
+	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 appear in the
+ * right order.
+ */
+static int parse_line(char *line, struct rdt_resource *r)
+{
+	char *dom = NULL, *id;
+	struct rdt_domain *d;
+	unsigned long dom_id;
+
+	list_for_each_entry(d, &r->domains, list) {
+		dom = strsep(&line, ";");
+		if (!dom)
+			return -EINVAL;
+		id = strsep(&dom, "=");
+		if (kstrtoul(id, 10, &dom_id) || dom_id != d->id)
+			return -EINVAL;
+		if (parse_cbm(dom, r))
+			return -EINVAL;
+	}
+
+	/* Any garbage at the end of the line? */
+	if (line && line[0])
+		return -EINVAL;
+	return 0;
+}
+
+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, idx = 0;
+
+	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) {
+		cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
+		d->cbm[msr_param.low] = r->tmp_cbms[idx++];
+	}
+	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 other cpus. */
+	smp_call_function_many(cpu_mask, rdt_cbm_update, &msr_param, 1);
+	put_cpu();
+
+	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_resource *r;
+	char *tok, *resname;
+	int closid, ret = 0;
+	u32 *l3_cbms = NULL;
+
+	/* 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;
+
+	/* get scratch space to save all the masks while we validate input */
+	for_each_enabled_rdt_resource(r) {
+		r->tmp_cbms = kcalloc(r->num_domains, sizeof(*l3_cbms),
+				      GFP_KERNEL);
+		if (!r->tmp_cbms) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		r->num_tmp_cbms = 0;
+	}
+
+	while ((tok = strsep(&buf, "\n")) != NULL) {
+		resname = 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;
+		}
+	}
+
+	/* Did the parser find all the masks we need? */
+	for_each_enabled_rdt_resource(r) {
+		if (r->num_tmp_cbms != r->num_domains) {
+			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);
+	for_each_enabled_rdt_resource(r) {
+		kfree(r->tmp_cbms);
+		r->tmp_cbms = NULL;
+	}
+	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:", r->name);
+	list_for_each_entry(dom, &r->domains, list) {
+		if (sep)
+			seq_puts(s, ";");
+		seq_printf(s, "%d=%x", dom->id, dom->cbm[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;
+}