smp: Inline on_each_cpu_cond() and on_each_cpu()

Simplify the code and avoid having an additional function on the stack
by inlining on_each_cpu_cond() and on_each_cpu().

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Nadav Amit <namit@vmware.com>
[ Minor edits. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210220231712.2475218-10-namit@vmware.com

1 files changed, 36 insertions, 14 deletions

diff --git a/include/linux/smp.h b/include/linux/smp.h
index 70c6f6284dcf..84a0b4828f66 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -50,30 +50,52 @@ extern unsigned int total_cpus;
 int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
 			     int wait);
 
+void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
+			   void *info, bool wait, const struct cpumask *mask);
+
+int smp_call_function_single_async(int cpu, call_single_data_t *csd);
+
 /*
  * Call a function on all processors
  */
-void on_each_cpu(smp_call_func_t func, void *info, int wait);
+static inline void on_each_cpu(smp_call_func_t func, void *info, int wait)
+{
+	on_each_cpu_cond_mask(NULL, func, info, wait, cpu_online_mask);
+}
 
-/*
- * Call a function on processors specified by mask, which might include
- * the local one.
+/**
+ * on_each_cpu_mask(): Run a function on processors specified by
+ * cpumask, which may include the local processor.
+ * @mask: The set of cpus to run on (only runs on online subset).
+ * @func: The function to run. This must be fast and non-blocking.
+ * @info: An arbitrary pointer to pass to the function.
+ * @wait: If true, wait (atomically) until function has completed
+ *        on other CPUs.
+ *
+ * If @wait is true, then returns once @func has returned.
+ *
+ * You must not call this function with disabled interrupts or from a
+ * hardware interrupt handler or from a bottom half handler.  The
+ * exception is that it may be used during early boot while
+ * early_boot_irqs_disabled is set.
  */
-void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
-		void *info, bool wait);
+static inline void on_each_cpu_mask(const struct cpumask *mask,
+				    smp_call_func_t func, void *info, bool wait)
+{
+	on_each_cpu_cond_mask(NULL, func, info, wait, mask);
+}
 
 /*
  * Call a function on each processor for which the supplied function
  * cond_func returns a positive value. This may include the local
- * processor.
+ * processor.  May be used during early boot while early_boot_irqs_disabled is
+ * set. Use local_irq_save/restore() instead of local_irq_disable/enable().
  */
-void on_each_cpu_cond(smp_cond_func_t cond_func, smp_call_func_t func,
-		      void *info, bool wait);
-
-void on_each_cpu_cond_mask(smp_cond_func_t cond_func, smp_call_func_t func,
-			   void *info, bool wait, const struct cpumask *mask);
-
-int smp_call_function_single_async(int cpu, call_single_data_t *csd);
+static inline void on_each_cpu_cond(smp_cond_func_t cond_func,
+				    smp_call_func_t func, void *info, bool wait)
+{
+	on_each_cpu_cond_mask(cond_func, func, info, wait, cpu_online_mask);
+}
 
 #ifdef CONFIG_SMP