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45239ba39a
Sometimes it is required to take actions based on if a CPU is a performance or efficiency core. As an example, intel_pstate driver uses the Intel core-type to determine CPU scaling. Also, some CPU vulnerabilities only affect a specific CPU type, like RFDS only affects Intel Atom. Hybrid systems that have variants P+E, P-only(Core) and E-only(Atom), it is not straightforward to identify which variant is affected by a type specific vulnerability. Such processors do have CPUID field that can uniquely identify them. Like, P+E, P-only and E-only enumerates CPUID.1A.CORE_TYPE identification, while P+E additionally enumerates CPUID.7.HYBRID. Based on this information, it is possible for boot CPU to identify if a system has mixed CPU types. Add a new field hw_cpu_type to struct cpuinfo_topology that stores the hardware specific CPU type. This saves the overhead of IPIs to get the CPU type of a different CPU. CPU type is populated early in the boot process, before vulnerabilities are enumerated. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Co-developed-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Link: https://lore.kernel.org/r/20241025171459.1093-5-mario.limonciello@amd.com
101 lines
3.1 KiB
C
101 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/debugfs.h>
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#include <asm/apic.h>
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#include <asm/processor.h>
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#include "cpu.h"
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static int cpu_debug_show(struct seq_file *m, void *p)
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{
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unsigned long cpu = (unsigned long)m->private;
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struct cpuinfo_x86 *c = per_cpu_ptr(&cpu_info, cpu);
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seq_printf(m, "online: %d\n", cpu_online(cpu));
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if (!c->initialized)
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return 0;
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seq_printf(m, "initial_apicid: %x\n", c->topo.initial_apicid);
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seq_printf(m, "apicid: %x\n", c->topo.apicid);
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seq_printf(m, "pkg_id: %u\n", c->topo.pkg_id);
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seq_printf(m, "die_id: %u\n", c->topo.die_id);
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seq_printf(m, "cu_id: %u\n", c->topo.cu_id);
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seq_printf(m, "core_id: %u\n", c->topo.core_id);
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seq_printf(m, "cpu_type: %s\n", get_topology_cpu_type_name(c));
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seq_printf(m, "logical_pkg_id: %u\n", c->topo.logical_pkg_id);
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seq_printf(m, "logical_die_id: %u\n", c->topo.logical_die_id);
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seq_printf(m, "llc_id: %u\n", c->topo.llc_id);
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seq_printf(m, "l2c_id: %u\n", c->topo.l2c_id);
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seq_printf(m, "amd_node_id: %u\n", c->topo.amd_node_id);
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seq_printf(m, "amd_nodes_per_pkg: %u\n", topology_amd_nodes_per_pkg());
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seq_printf(m, "num_threads: %u\n", __num_threads_per_package);
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seq_printf(m, "num_cores: %u\n", __num_cores_per_package);
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seq_printf(m, "max_dies_per_pkg: %u\n", __max_dies_per_package);
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seq_printf(m, "max_threads_per_core:%u\n", __max_threads_per_core);
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return 0;
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}
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static int cpu_debug_open(struct inode *inode, struct file *file)
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{
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return single_open(file, cpu_debug_show, inode->i_private);
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}
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static const struct file_operations dfs_cpu_ops = {
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.open = cpu_debug_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static int dom_debug_show(struct seq_file *m, void *p)
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{
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static const char *domain_names[TOPO_MAX_DOMAIN] = {
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[TOPO_SMT_DOMAIN] = "Thread",
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[TOPO_CORE_DOMAIN] = "Core",
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[TOPO_MODULE_DOMAIN] = "Module",
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[TOPO_TILE_DOMAIN] = "Tile",
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[TOPO_DIE_DOMAIN] = "Die",
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[TOPO_DIEGRP_DOMAIN] = "DieGrp",
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[TOPO_PKG_DOMAIN] = "Package",
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};
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unsigned int dom, nthreads = 1;
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for (dom = 0; dom < TOPO_MAX_DOMAIN; dom++) {
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nthreads *= x86_topo_system.dom_size[dom];
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seq_printf(m, "domain: %-10s shift: %u dom_size: %5u max_threads: %5u\n",
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domain_names[dom], x86_topo_system.dom_shifts[dom],
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x86_topo_system.dom_size[dom], nthreads);
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}
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return 0;
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}
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static int dom_debug_open(struct inode *inode, struct file *file)
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{
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return single_open(file, dom_debug_show, inode->i_private);
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}
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static const struct file_operations dfs_dom_ops = {
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.open = dom_debug_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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};
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static __init int cpu_init_debugfs(void)
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{
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struct dentry *dir, *base = debugfs_create_dir("topo", arch_debugfs_dir);
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unsigned long id;
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char name[24];
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debugfs_create_file("domains", 0444, base, NULL, &dfs_dom_ops);
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dir = debugfs_create_dir("cpus", base);
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for_each_possible_cpu(id) {
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sprintf(name, "%lu", id);
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debugfs_create_file(name, 0444, dir, (void *)id, &dfs_cpu_ops);
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}
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return 0;
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}
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late_initcall(cpu_init_debugfs);
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