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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - arch/x86/kernel/cpu/intel_rdt_schemata.c
2 * Resource Director Technology(RDT)
3 * - Cache Allocation code.
5 * Copyright (C) 2016 Intel Corporation
8 * Fenghua Yu <fenghua.yu@intel.com>
9 * Tony Luck <tony.luck@intel.com>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms and conditions of the GNU General Public License,
13 * version 2, as published by the Free Software Foundation.
15 * This program is distributed in the hope it will be useful, but WITHOUT
16 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
17 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
20 * More information about RDT be found in the Intel (R) x86 Architecture
21 * Software Developer Manual June 2016, volume 3, section 17.17.
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26 #include <linux/kernfs.h>
27 #include <linux/seq_file.h>
28 #include <linux/slab.h>
29 #include <asm/intel_rdt.h>
32 * Check whether a cache bit mask is valid. The SDM says:
33 * Please note that all (and only) contiguous '1' combinations
34 * are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
35 * Additionally Haswell requires at least two bits set.
37 static bool cbm_validate(unsigned long var
, struct rdt_resource
*r
)
39 unsigned long first_bit
, zero_bit
;
41 if (var
== 0 || var
> r
->max_cbm
)
44 first_bit
= find_first_bit(&var
, r
->cbm_len
);
45 zero_bit
= find_next_zero_bit(&var
, r
->cbm_len
, first_bit
);
47 if (find_next_bit(&var
, r
->cbm_len
, zero_bit
) < r
->cbm_len
)
50 if ((zero_bit
- first_bit
) < r
->min_cbm_bits
)
56 * Read one cache bit mask (hex). Check that it is valid for the current
59 static int parse_cbm(char *buf
, struct rdt_resource
*r
)
64 ret
= kstrtoul(buf
, 16, &data
);
67 if (!cbm_validate(data
, r
))
69 r
->tmp_cbms
[r
->num_tmp_cbms
++] = data
;
75 * For each domain in this resource we expect to find a series of:
77 * separated by ";". The "id" is in decimal, and must appear in the
80 static int parse_line(char *line
, struct rdt_resource
*r
)
82 char *dom
= NULL
, *id
;
86 list_for_each_entry(d
, &r
->domains
, list
) {
87 dom
= strsep(&line
, ";");
90 id
= strsep(&dom
, "=");
91 if (kstrtoul(id
, 10, &dom_id
) || dom_id
!= d
->id
)
93 if (parse_cbm(dom
, r
))
97 /* Any garbage at the end of the line? */
103 static int update_domains(struct rdt_resource
*r
, int closid
)
105 struct msr_param msr_param
;
106 cpumask_var_t cpu_mask
;
107 struct rdt_domain
*d
;
110 if (!zalloc_cpumask_var(&cpu_mask
, GFP_KERNEL
))
113 msr_param
.low
= closid
;
114 msr_param
.high
= msr_param
.low
+ 1;
117 list_for_each_entry(d
, &r
->domains
, list
) {
118 cpumask_set_cpu(cpumask_any(&d
->cpu_mask
), cpu_mask
);
119 d
->cbm
[msr_param
.low
] = r
->tmp_cbms
[idx
++];
122 /* Update CBM on this cpu if it's in cpu_mask. */
123 if (cpumask_test_cpu(cpu
, cpu_mask
))
124 rdt_cbm_update(&msr_param
);
125 /* Update CBM on other cpus. */
126 smp_call_function_many(cpu_mask
, rdt_cbm_update
, &msr_param
, 1);
129 free_cpumask_var(cpu_mask
);
134 ssize_t
rdtgroup_schemata_write(struct kernfs_open_file
*of
,
135 char *buf
, size_t nbytes
, loff_t off
)
137 struct rdtgroup
*rdtgrp
;
138 struct rdt_resource
*r
;
143 /* Valid input requires a trailing newline */
144 if (nbytes
== 0 || buf
[nbytes
- 1] != '\n')
146 buf
[nbytes
- 1] = '\0';
148 rdtgrp
= rdtgroup_kn_lock_live(of
->kn
);
150 rdtgroup_kn_unlock(of
->kn
);
154 closid
= rdtgrp
->closid
;
156 /* get scratch space to save all the masks while we validate input */
157 for_each_enabled_rdt_resource(r
) {
158 r
->tmp_cbms
= kcalloc(r
->num_domains
, sizeof(*l3_cbms
),
167 while ((tok
= strsep(&buf
, "\n")) != NULL
) {
168 resname
= strsep(&tok
, ":");
173 for_each_enabled_rdt_resource(r
) {
174 if (!strcmp(resname
, r
->name
) &&
175 closid
< r
->num_closid
) {
176 ret
= parse_line(tok
, r
);
188 /* Did the parser find all the masks we need? */
189 for_each_enabled_rdt_resource(r
) {
190 if (r
->num_tmp_cbms
!= r
->num_domains
) {
196 for_each_enabled_rdt_resource(r
) {
197 ret
= update_domains(r
, closid
);
203 rdtgroup_kn_unlock(of
->kn
);
204 for_each_enabled_rdt_resource(r
) {
208 return ret
?: nbytes
;
211 static void show_doms(struct seq_file
*s
, struct rdt_resource
*r
, int closid
)
213 struct rdt_domain
*dom
;
216 seq_printf(s
, "%s:", r
->name
);
217 list_for_each_entry(dom
, &r
->domains
, list
) {
220 seq_printf(s
, "%d=%x", dom
->id
, dom
->cbm
[closid
]);
226 int rdtgroup_schemata_show(struct kernfs_open_file
*of
,
227 struct seq_file
*s
, void *v
)
229 struct rdtgroup
*rdtgrp
;
230 struct rdt_resource
*r
;
233 rdtgrp
= rdtgroup_kn_lock_live(of
->kn
);
235 closid
= rdtgrp
->closid
;
236 for_each_enabled_rdt_resource(r
) {
237 if (closid
< r
->num_closid
)
238 show_doms(s
, r
, closid
);
243 rdtgroup_kn_unlock(of
->kn
);