x86/mce/amd: Init bank kobjects

The MCA Thresholding structures are created during CPU init and they do
not depend on sysfs enumeration for functionality.

The kobject should be initialized during CPU init, and they should
persist throughout run time. The kobjects can be added/deleted from a
parent sysfs interface, as needed.

Initialize the bank kobjects during CPU init to start. Block kobjects
and names will be added later.

Keep old kobject until old code is removed.

Signed-off-by: Yazen Ghannam <yazen.ghannam@amd.com>

arch/x86/kernel/cpu/mce/amd.c

@@ -336,7 +336,8 @@ struct threshold_block {
 };
 
 struct threshold_bank {
-	struct kobject		*kobj;
+	struct kobject		*kobj_old;
+	struct kobject		kobj;
 	struct threshold_block	*blocks;
 	struct list_head	block_list;
 };
@@ -576,6 +577,16 @@ static void save_bank_type(unsigned int bank, struct sysfs_bank_id bank_ids[], u
 	bank_ids[bank].sysfs_id = bank_counts[bank_type]++;
 }
 
+#define to_bank(k)	container_of(k, struct threshold_bank, kobj)
+static void threshold_bank_release(struct kobject *kobj)
+{
+	kfree(to_bank(kobj));
+}
+
+static const struct kobj_type threshold_bank_ktype = {
+	.release		= threshold_bank_release,
+};
+
 /*
  * Don't enable thresholding banks for the following conditions:
  * - MC4_MISC thresholding is not supported on Family 0x15.
@@ -739,6 +750,16 @@ bool amd_filter_mce(struct mce *m)
 	return false;
 }
 
+static void init_threshold_bank_kobjects(struct threshold_bank *thr_bank)
+{
+	/* There may be empty banks in the array. Skip them. */
+	if (!thr_bank)
+		return;
+
+	/* kref is set to 1. */
+	kobject_init(&thr_bank->kobj, &threshold_bank_ktype);
+}
+
 static u64 get_mca_intr_cfg(void)
 {
 	u64 mca_intr_cfg;
@@ -785,6 +806,9 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 		return;
 	}
 
+	for (bank = 0; bank < num_banks; bank++)
+		init_threshold_bank_kobjects(thr_banks[bank]);
+
 	this_cpu_write(threshold_banks, thr_banks);
 }
 
@@ -1212,7 +1236,7 @@ static int allocate_threshold_blocks(unsigned int cpu, struct threshold_bank *tb
 	else
 		tb->blocks = b;
 
-	err = kobject_init_and_add(&b->kobj, &threshold_ktype, tb->kobj, get_name(cpu, bank, b));
+	err = kobject_init_and_add(&b->kobj, &threshold_ktype, tb->kobj_old, get_name(cpu, bank, b));
 	if (err)
 		goto out_free;
 recurse:
@@ -1255,8 +1279,8 @@ static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
 	}
 
 	/* Associate the bank with the per-CPU MCE device */
-	b->kobj = kobject_create_and_add(name, &dev->kobj);
-	if (!b->kobj) {
+	b->kobj_old = kobject_create_and_add(name, &dev->kobj);
+	if (!b->kobj_old) {
 		err = -EINVAL;
 		goto out_free;
 	}
@@ -1269,7 +1293,7 @@ static int threshold_create_bank(struct threshold_bank **bp, unsigned int cpu,
 	return 0;
 
 out_kobj:
-	kobject_put(b->kobj);
+	kobject_put(b->kobj_old);
 out_free:
 	kfree(b);
 out:
@@ -1301,7 +1325,7 @@ static void threshold_remove_bank(struct threshold_bank *bank)
 	deallocate_threshold_blocks(bank);
 
 out_free:
-	kobject_put(bank->kobj);
+	kobject_put(bank->kobj_old);
 	kfree(bank);
 }