1 files changed, 59 insertions, 74 deletions

diff --git a/arch/x86/kernel/itmt.c b/arch/x86/kernel/itmt.c
index 9ff480e94511..243a769fdd97 100644
--- a/arch/x86/kernel/itmt.c
+++ b/arch/x86/kernel/itmt.c
@@ -19,6 +19,7 @@
 #include <linux/sched.h>
 #include <linux/cpumask.h>
 #include <linux/cpuset.h>
+#include <linux/debugfs.h>
 #include <linux/mutex.h>
 #include <linux/sysctl.h>
 #include <linux/nodemask.h>
@@ -34,59 +35,51 @@ static bool __read_mostly sched_itmt_capable;
  * of higher turbo frequency for cpus supporting Intel Turbo Boost Max
  * Technology 3.0.
  *
- * It can be set via /proc/sys/kernel/sched_itmt_enabled
+ * It can be set via /sys/kernel/debug/x86/sched_itmt_enabled
  */
-unsigned int __read_mostly sysctl_sched_itmt_enabled;
+bool __read_mostly sysctl_sched_itmt_enabled;
 
-static int sched_itmt_update_handler(struct ctl_table *table, int write,
-				     void *buffer, size_t *lenp, loff_t *ppos)
+static ssize_t sched_itmt_enabled_write(struct file *filp,
+					const char __user *ubuf,
+					size_t cnt, loff_t *ppos)
 {
-	unsigned int old_sysctl;
-	int ret;
+	ssize_t result;
+	bool orig;
 
-	mutex_lock(&itmt_update_mutex);
+	guard(mutex)(&itmt_update_mutex);
 
-	if (!sched_itmt_capable) {
-		mutex_unlock(&itmt_update_mutex);
-		return -EINVAL;
-	}
-
-	old_sysctl = sysctl_sched_itmt_enabled;
-	ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos);
+	orig = sysctl_sched_itmt_enabled;
+	result = debugfs_write_file_bool(filp, ubuf, cnt, ppos);
 
-	if (!ret && write && old_sysctl != sysctl_sched_itmt_enabled) {
+	if (sysctl_sched_itmt_enabled != orig) {
 		x86_topology_update = true;
 		rebuild_sched_domains();
 	}
 
-	mutex_unlock(&itmt_update_mutex);
-
-	return ret;
+	return result;
 }
 
-static struct ctl_table itmt_kern_table[] = {
-	{
-		.procname	= "sched_itmt_enabled",
-		.data		= &sysctl_sched_itmt_enabled,
-		.maxlen		= sizeof(unsigned int),
-		.mode		= 0644,
-		.proc_handler	= sched_itmt_update_handler,
-		.extra1		= SYSCTL_ZERO,
-		.extra2		= SYSCTL_ONE,
-	},
-	{}
-};
+static int sched_core_priority_show(struct seq_file *s, void *unused)
+{
+	int cpu;
+
+	seq_puts(s, "CPU #\tPriority\n");
+	for_each_possible_cpu(cpu)
+		seq_printf(s, "%d\t%d\n", cpu, arch_asym_cpu_priority(cpu));
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(sched_core_priority);
 
-static struct ctl_table itmt_root_table[] = {
-	{
-		.procname	= "kernel",
-		.mode		= 0555,
-		.child		= itmt_kern_table,
-	},
-	{}
+static const struct file_operations dfs_sched_itmt_fops = {
+	.read =         debugfs_read_file_bool,
+	.write =        sched_itmt_enabled_write,
+	.open =         simple_open,
+	.llseek =       default_llseek,
 };
 
-static struct ctl_table_header *itmt_sysctl_header;
+static struct dentry *dfs_sched_itmt;
+static struct dentry *dfs_sched_core_prio;
 
 /**
  * sched_set_itmt_support() - Indicate platform supports ITMT
@@ -107,16 +100,26 @@ static struct ctl_table_header *itmt_sysctl_header;
  */
 int sched_set_itmt_support(void)
 {
-	mutex_lock(&itmt_update_mutex);
+	guard(mutex)(&itmt_update_mutex);
 
-	if (sched_itmt_capable) {
-		mutex_unlock(&itmt_update_mutex);
+	if (sched_itmt_capable)
 		return 0;
+
+	dfs_sched_itmt = debugfs_create_file_unsafe("sched_itmt_enabled",
+						    0644,
+						    arch_debugfs_dir,
+						    &sysctl_sched_itmt_enabled,
+						    &dfs_sched_itmt_fops);
+	if (IS_ERR_OR_NULL(dfs_sched_itmt)) {
+		dfs_sched_itmt = NULL;
+		return -ENOMEM;
 	}
 
-	itmt_sysctl_header = register_sysctl_table(itmt_root_table);
-	if (!itmt_sysctl_header) {
-		mutex_unlock(&itmt_update_mutex);
+	dfs_sched_core_prio = debugfs_create_file("sched_core_priority", 0644,
+						  arch_debugfs_dir, NULL,
+						  &sched_core_priority_fops);
+	if (IS_ERR_OR_NULL(dfs_sched_core_prio)) {
+		dfs_sched_core_prio = NULL;
 		return -ENOMEM;
 	}
 
@@ -127,8 +130,6 @@ int sched_set_itmt_support(void)
 	x86_topology_update = true;
 	rebuild_sched_domains();
 
-	mutex_unlock(&itmt_update_mutex);
-
 	return 0;
 }
 
@@ -144,18 +145,17 @@ int sched_set_itmt_support(void)
  */
 void sched_clear_itmt_support(void)
 {
-	mutex_lock(&itmt_update_mutex);
+	guard(mutex)(&itmt_update_mutex);
 
-	if (!sched_itmt_capable) {
-		mutex_unlock(&itmt_update_mutex);
+	if (!sched_itmt_capable)
 		return;
-	}
+
 	sched_itmt_capable = false;
 
-	if (itmt_sysctl_header) {
-		unregister_sysctl_table(itmt_sysctl_header);
-		itmt_sysctl_header = NULL;
-	}
+	debugfs_remove(dfs_sched_itmt);
+	dfs_sched_itmt = NULL;
+	debugfs_remove(dfs_sched_core_prio);
+	dfs_sched_core_prio = NULL;
 
 	if (sysctl_sched_itmt_enabled) {
 		/* disable sched_itmt if we are no longer ITMT capable */
@@ -163,8 +163,6 @@ void sched_clear_itmt_support(void)
 		x86_topology_update = true;
 		rebuild_sched_domains();
 	}
-
-	mutex_unlock(&itmt_update_mutex);
 }
 
 int arch_asym_cpu_priority(int cpu)
@@ -174,32 +172,19 @@ int arch_asym_cpu_priority(int cpu)
 
 /**
  * sched_set_itmt_core_prio() - Set CPU priority based on ITMT
- * @prio:	Priority of cpu core
- * @core_cpu:	The cpu number associated with the core
+ * @prio:	Priority of @cpu
+ * @cpu:	The CPU number
  *
  * The pstate driver will find out the max boost frequency
  * and call this function to set a priority proportional
- * to the max boost frequency. CPU with higher boost
+ * to the max boost frequency. CPUs with higher boost
  * frequency will receive higher priority.
  *
  * No need to rebuild sched domain after updating
  * the CPU priorities. The sched domains have no
  * dependency on CPU priorities.
  */
-void sched_set_itmt_core_prio(int prio, int core_cpu)
+void sched_set_itmt_core_prio(int prio, int cpu)
 {
-	int cpu, i = 1;
-
-	for_each_cpu(cpu, topology_sibling_cpumask(core_cpu)) {
-		int smt_prio;
-
-		/*
-		 * Ensure that the siblings are moved to the end
-		 * of the priority chain and only used when
-		 * all other high priority cpus are out of capacity.
-		 */
-		smt_prio = prio * smp_num_siblings / (i * i);
-		per_cpu(sched_core_priority, cpu) = smt_prio;
-		i++;
-	}
+	per_cpu(sched_core_priority, cpu) = prio;
 }