sched: programmable: Add helper function for cpu topology.

hulk inclusion
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I5KUFB
CVE: NA

--------------------------------

Add bpf helper function bpf_init_cpu_topology()
which obtains cpu topology info through the macros
topology_* that are defined by include/linux/topology.h, and
save it in BPF MAP.

The cpu topology info are useful to select core in userspace.
Signed-off-by: NChen Hui <judy.chenhui@huawei.com>
Signed-off-by: NRen Zhijie <renzhijie2@huawei.com>

include/linux/bpf_topology.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+/*
+ * Copyright (C) 2022. Huawei Technologies Co., Ltd. All rights reserved.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#ifndef _LINUX_BPF_TOPOLOGY_H
+#define _LINUX_BPF_TOPOLOGY_H
+
+#include <linux/cpumask.h>
+
+struct bpf_cpu_topology {
+		int cpu;
+		int core_id;
+		int cluster_id;
+		int die_id;
+		int physical_package_id;
+		int numa_node;
+		struct cpumask thread_siblings;
+		struct cpumask core_siblings;
+		struct cpumask cluster_cpus;
+		struct cpumask die_cpus;
+		struct cpumask package_cpus;
+		struct cpumask node_cpu_lists;
+};
+
+struct bpf_cpumask_info {
+	unsigned int nums_possible_cpus;
+	unsigned int nums_active_cpus;
+	unsigned int nums_isolate_cpus;
+	unsigned int nr_cpu_ids;
+	unsigned int bpf_nr_cpumask_bits;
+	struct cpumask cpu_possible_cpumask;
+	struct cpumask cpu_active_cpumask;
+	struct cpumask cpu_isolate_cpumask;
+};
+
+#endif /* _LINUX_BPF_TOPOLOGY_H */

include/uapi/linux/bpf.h

@@ -3846,6 +3846,18 @@ union bpf_attr {
  *		Get *cpu* capacity and store in *ctx*.
  *	Return
  *		0 on success, or a negative error in case of failure.
+ *
+ * long bpf_init_cpu_topology(struct bpf_map *map, u64 flags)
+ *	Description
+ *		Initializing the cpu topology which used for bpf prog.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_get_cpumask_info(struct bpf_cpumask_info *cpus, int len)
+ *	Description
+ *		Get system cpus returned in *cpus*.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -4020,6 +4032,8 @@ union bpf_attr {
 	FN(sched_cpu_nr_running_of),	\
 	FN(sched_cpu_idle_stat_of),		\
 	FN(sched_cpu_capacity_of),		\
+	FN(init_cpu_topology),	\
+	FN(get_cpumask_info),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper

kernel/sched/Makefile

@@ -36,4 +36,5 @@ obj-$(CONFIG_CPU_FREQ_GOV_SCHEDUTIL) += cpufreq_schedutil.o
 obj-$(CONFIG_MEMBARRIER) += membarrier.o
 obj-$(CONFIG_CPU_ISOLATION) += isolation.o
 obj-$(CONFIG_PSI) += psi.o
-obj-$(CONFIG_BPF_SCHED) += bpf_sched.o
+obj-$(CONFIG_BPF_SCHED) += bpf_sched.o
\ No newline at end of file
+obj-$(CONFIG_BPF_SCHED) += bpf_topology.o
\ No newline at end of file

kernel/sched/bpf_sched.c

@@ -4,6 +4,7 @@
 #include <linux/bpf_verifier.h>
 #include <linux/bpf_sched.h>
 #include <linux/btf_ids.h>
+#include <linux/bpf_topology.h>
 #include "sched.h"
 
 DEFINE_STATIC_KEY_FALSE(bpf_sched_enabled_key);
@@ -26,6 +27,9 @@ BTF_SET_START(bpf_sched_hooks)
 #undef BPF_SCHED_HOOK
 BTF_SET_END(bpf_sched_hooks)
 
+const struct bpf_func_proto bpf_init_cpu_topology_proto __weak;
+const struct bpf_func_proto bpf_get_cpumask_info_proto __weak;
+
 int bpf_sched_verify_prog(struct bpf_verifier_log *vlog,
 			  const struct bpf_prog *prog)
 {
@@ -424,6 +428,10 @@ bpf_sched_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
 		return &bpf_sched_cpu_idle_stat_of_proto;
 	case BPF_FUNC_sched_cpu_capacity_of:
 		return &bpf_sched_cpu_capacity_of_proto;
+	case BPF_FUNC_init_cpu_topology:
+		return &bpf_init_cpu_topology_proto;
+	case BPF_FUNC_get_cpumask_info:
+		return &bpf_get_cpumask_info_proto;
 	default:
 		return bpf_base_func_proto(func_id);
 	}

kernel/sched/bpf_topology.c

+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2022. Huawei Technologies Co., Ltd. All rights reserved.
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ */
+
+#include <linux/bpf.h>
+#include <linux/btf_ids.h>
+#include <linux/bpf_verifier.h>
+#include <linux/topology.h>
+#include <linux/cpumask.h>
+#include <linux/bpf_topology.h>
+#include <linux/sched/isolation.h>
+
+static void bpf_update_cpu_topology(struct bpf_cpu_topology *cpu_topology, int cpu)
+{
+	cpu_topology->cpu = cpu;
+	cpu_topology->core_id = topology_core_id(cpu);
+	cpu_topology->cluster_id = topology_cluster_id(cpu);
+	cpu_topology->die_id = topology_die_id(cpu);
+	cpu_topology->physical_package_id = topology_physical_package_id(cpu);
+	cpu_topology->numa_node = cpu_to_node(cpu);
+	cpumask_copy(&cpu_topology->thread_siblings, topology_sibling_cpumask(cpu));
+	cpumask_copy(&cpu_topology->core_siblings, topology_core_cpumask(cpu));
+	cpumask_copy(&cpu_topology->cluster_cpus, topology_cluster_cpumask(cpu));
+	cpumask_copy(&cpu_topology->die_cpus, topology_die_cpumask(cpu));
+	cpumask_copy(&cpu_topology->package_cpus, topology_core_cpumask(cpu));
+	cpumask_copy(&cpu_topology->node_cpu_lists, cpumask_of_node(cpu_to_node(cpu)));
+}
+
+BPF_CALL_2(bpf_init_cpu_topology, struct bpf_map *, map, u64, flags)
+{
+	const struct cpumask *cpu_map = cpu_active_mask;
+	int ret = 0;
+	int i = -1;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !rcu_read_lock_bh_held());
+	for_each_cpu(i, cpu_map) {
+		struct bpf_cpu_topology topo;
+
+		bpf_update_cpu_topology(&topo, i);
+		ret = map->ops->map_update_elem(map, &i, &topo, flags);
+		if (ret) {
+			int idx = i;
+
+			for (; idx >= 0; idx--)
+				map->ops->map_delete_elem(map, &idx);
+			break;
+		}
+	}
+
+	return ret;
+}
+
+BTF_ID_LIST_SINGLE(bpf_cpu_topology_ids, struct, bpf_cpu_topology)
+
+const struct bpf_func_proto bpf_init_cpu_topology_proto = {
+	.func		= bpf_init_cpu_topology,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_CONST_MAP_PTR,
+	.arg2_type	= ARG_ANYTHING,
+};
+
+BPF_CALL_2(bpf_get_cpumask_info, struct bpf_cpumask_info *, cpus,
+	   int, len)
+{
+	if (len != sizeof(*cpus))
+		return -EINVAL;
+
+	cpumask_copy(&cpus->cpu_possible_cpumask, cpu_possible_mask);
+	cpumask_copy(&cpus->cpu_active_cpumask, cpu_active_mask);
+	cpumask_copy(&cpus->cpu_isolate_cpumask, housekeeping_cpumask(HK_FLAG_DOMAIN));
+	cpus->nums_possible_cpus = num_possible_cpus();
+	cpus->nums_active_cpus = num_active_cpus();
+	cpus->nums_isolate_cpus = cpumask_weight(&cpus->cpu_isolate_cpumask);
+	cpus->nr_cpu_ids = nr_cpu_ids;
+	cpus->bpf_nr_cpumask_bits = nr_cpumask_bits;
+
+	return 0;
+}
+
+const struct bpf_func_proto bpf_get_cpumask_info_proto = {
+	.func		= bpf_get_cpumask_info,
+	.gpl_only	= false,
+	.ret_type	= RET_INTEGER,
+	.arg1_type	= ARG_PTR_TO_UNINIT_MEM,
+	.arg2_type	= ARG_CONST_SIZE,
+};

scripts/bpf_helpers_doc.py

@@ -441,6 +441,8 @@ class PrinterHelpers(Printer):
             'struct bpf_sched_cpu_nr_running',
             'struct bpf_sched_cpu_idle_stat',
             'struct bpf_sched_cpu_capacity',
+            'struct bpf_cpu_topology',
+            'struct bpf_cpumask_info',
     ]
     known_types = {
             '...',
@@ -490,6 +492,8 @@ class PrinterHelpers(Printer):
             'struct bpf_sched_cpu_nr_running',
             'struct bpf_sched_cpu_idle_stat',
             'struct bpf_sched_cpu_capacity',
+            'struct bpf_cpu_topology',
+            'struct bpf_cpumask_info',
     }
     mapped_types = {
             'u8': '__u8',

tools/include/uapi/linux/bpf.h

@@ -3846,6 +3846,18 @@ union bpf_attr {
  *		Get *cpu* capacity and store in *ctx*.
  *	Return
  *		0 on success, or a negative error in case of failure.
+ *
+ * long bpf_init_cpu_topology(struct bpf_map *map, u64 flags)
+ *	Description
+ *		Initializing the cpu topology which used for bpf prog.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
+ *
+ * int bpf_get_cpumask_info(struct bpf_cpumask_info *cpus, int len)
+ *	Description
+ *		Get system cpus returned in *cpus*.
+ *	Return
+ *		0 on success, or a negative error in case of failure.
  */
 #define __BPF_FUNC_MAPPER(FN)		\
 	FN(unspec),			\
@@ -4020,6 +4032,8 @@ union bpf_attr {
 	FN(sched_cpu_nr_running_of),	\
 	FN(sched_cpu_idle_stat_of),	\
 	FN(sched_cpu_capacity_of),	\
+	FN(init_cpu_topology),	\
+	FN(get_cpumask_info),		\
 	/* */
 
 /* integer value in 'imm' field of BPF_CALL instruction selects which helper