--- /dev/null
+/*
+ * 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;
+}
projects / platform / kernel / linux-rpi3.git / commitdiff