WARNING: line length of 84 exceeds 80 columns
#51: FILE: include/linux/cpuhplock.h:50:
+static inline int cpuhp_offline_cb(struct cpumask *mask, cpuhp_cb_t func, void *arg)

CHECK: Please use a blank line after function/struct/union/enum declarations
#55: FILE: include/linux/cpuhplock.h:54:
+}
+#define cpuhp_offline_cb_mode	false

WARNING: line length of 84 exceeds 80 columns
#70: FILE: kernel/cpu.c:1526:
+ * cpuhp_offline_cb - offline CPUs, invoke callback function & online CPUs afterward

CHECK: Alignment should match open parenthesis
#82: FILE: kernel/cpu.c:1538:
+	if (WARN_ON_ONCE(cpumask_empty(mask) ||
+	   !cpumask_subset(mask, cpu_online_mask)))

WARNING: line length of 84 exceeds 80 columns
#85: FILE: kernel/cpu.c:1541:
+	pr_debug("%s: begin (CPU list = %*pbl)\n", __func__, cpumask_pr_args(mask));

WARNING: data_race without comment
#122: FILE: kernel/cpu.c:1578:
+			if (!data_race(cpu_hotplug_disabled))

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
#133: FILE: kernel/cpu.c:1589:
+	pr_debug("%s: end\n", __func__);

total: 0 errors, 5 warnings, 2 checks, 104 lines checked

NOTE: For some of the reported defects, checkpatch may be able to
      mechanically convert to the typical style using --fix or --fix-inplace.

Commit c7c21f668c97 ("cpu/hotplug: Add a new cpuhp_offline_cb() API") has style problems, please review.

NOTE: Ignored message types: ALLOC_SIZEOF_STRUCT BAD_REPORTED_BY_LINK CAMELCASE COMMIT_LOG_LONG_LINE FILE_PATH_CHANGES GIT_COMMIT_ID MACRO_ARG_REUSE NO_AUTHOR_SIGN_OFF

NOTE: If any of the errors are false positives, please report
      them to the maintainer, see CHECKPATCH in MAINTAINERS.
total: 0 errors, 5 warnings, 2 checks, 104 lines checked