Commit 48525fd1 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/cpu: Provide debug interface 



Provide debug files which dump the topology related information of
cpuinfo_x86. This is useful to validate the upcoming conversion of the
topology evaluation for correctness or bug compatibility.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarJuergen Gross <jgross@suse.com>
Tested-by: default avatarSohil Mehta <sohil.mehta@intel.com>
Tested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Tested-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: default avatarZhang Rui <rui.zhang@intel.com>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230814085113.353191313@linutronix.de
parent 90781f0c

arch/x86/kernel/cpu/Makefile

+2 −0
Original line number Diff line number Diff line
@@ -54,6 +54,8 @@ obj-$(CONFIG_X86_LOCAL_APIC) += perfctr-watchdog.o 
obj-$(CONFIG_HYPERVISOR_GUEST)		+= vmware.o hypervisor.o mshyperv.o

obj-$(CONFIG_ACRN_GUEST)		+= acrn.o



obj-$(CONFIG_DEBUG_FS)			+= debugfs.o



quiet_cmd_mkcapflags = MKCAP   $@

      cmd_mkcapflags = $(CONFIG_SHELL) $(srctree)/$(src)/mkcapflags.sh $@ $^

arch/x86/kernel/cpu/debugfs.c

0 → 100644
+58 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0



#include <linux/debugfs.h>



#include <asm/apic.h>

#include <asm/processor.h>



static int cpu_debug_show(struct seq_file *m, void *p)

{

	unsigned long cpu = (unsigned long)m->private;

	struct cpuinfo_x86 *c = per_cpu_ptr(&cpu_info, cpu);



	seq_printf(m, "online:              %d\n", cpu_online(cpu));

	if (!c->initialized)

		return 0;



	seq_printf(m, "initial_apicid:      %x\n", c->topo.initial_apicid);

	seq_printf(m, "apicid:              %x\n", c->topo.apicid);

	seq_printf(m, "pkg_id:              %u\n", c->topo.pkg_id);

	seq_printf(m, "die_id:              %u\n", c->topo.die_id);

	seq_printf(m, "cu_id:               %u\n", c->topo.cu_id);

	seq_printf(m, "core_id:             %u\n", c->topo.core_id);

	seq_printf(m, "logical_pkg_id:      %u\n", c->topo.logical_pkg_id);

	seq_printf(m, "logical_die_id:      %u\n", c->topo.logical_die_id);

	seq_printf(m, "llc_id:              %u\n", c->topo.llc_id);

	seq_printf(m, "l2c_id:              %u\n", c->topo.l2c_id);

	seq_printf(m, "max_cores:           %u\n", c->x86_max_cores);

	seq_printf(m, "max_die_per_pkg:     %u\n", __max_die_per_package);

	seq_printf(m, "smp_num_siblings:    %u\n", smp_num_siblings);

	return 0;

}



static int cpu_debug_open(struct inode *inode, struct file *file)

{

	return single_open(file, cpu_debug_show, inode->i_private);

}



static const struct file_operations dfs_cpu_ops = {

	.open		= cpu_debug_open,

	.read		= seq_read,

	.llseek		= seq_lseek,

	.release	= single_release,

};



static __init int cpu_init_debugfs(void)

{

	struct dentry *dir, *base = debugfs_create_dir("topo", arch_debugfs_dir);

	unsigned long id;

	char name[24];



	dir = debugfs_create_dir("cpus", base);

	for_each_possible_cpu(id) {

		sprintf(name, "%lu", id);

		debugfs_create_file(name, 0444, dir, (void *)id, &dfs_cpu_ops);

	}

	return 0;

}

late_initcall(cpu_init_debugfs);