3 files changed, 253 insertions, 1 deletions

diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index b4334e86c1a9..c9f8c818d104 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -34,7 +34,7 @@ obj-$(CONFIG_CPU_SUP_CENTAUR)		+= centaur.o
 obj-$(CONFIG_CPU_SUP_TRANSMETA_32)      += transmeta.o
 obj-$(CONFIG_CPU_SUP_UMC_32)            += umc.o
 
-obj-$(CONFIG_INTEL_RDT_A)       += intel_rdt.o intel_rdt_rdtgroup.o
+obj-$(CONFIG_INTEL_RDT_A)       += intel_rdt.o intel_rdt_rdtgroup.o intel_rdt_schemata.o
 
 obj-$(CONFIG_X86_MCE)                   += mcheck/
 obj-$(CONFIG_MTRR)                      += mtrr/
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 5cc0865f2908..5c4bab9452b0 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -440,6 +440,13 @@ static struct rftype rdtgroup_base_files[] = {
                 .write          = rdtgroup_tasks_write,
                 .seq_show       = rdtgroup_tasks_show,
         },
+        {
+                .name           = "schemata",
+                .mode           = 0644,
+                .kf_ops         = &rdtgroup_kf_single_ops,
+                .write          = rdtgroup_schemata_write,
+                .seq_show       = rdtgroup_schemata_show,
+        },
 };
 
 static int rdt_num_closids_show(struct kernfs_open_file *of,
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;
+}