v4.19.13 snapshot.
diff --git a/include/linux/smp.h b/include/linux/smp.h
new file mode 100644
index 0000000..9fb239e
--- /dev/null
+++ b/include/linux/smp.h
@@ -0,0 +1,224 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_SMP_H
+#define __LINUX_SMP_H
+
+/*
+ * Generic SMP support
+ * Alan Cox. <alan@redhat.com>
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/list.h>
+#include <linux/cpumask.h>
+#include <linux/init.h>
+#include <linux/llist.h>
+
+typedef void (*smp_call_func_t)(void *info);
+struct __call_single_data {
+ struct llist_node llist;
+ smp_call_func_t func;
+ void *info;
+ unsigned int flags;
+};
+
+/* Use __aligned() to avoid to use 2 cache lines for 1 csd */
+typedef struct __call_single_data call_single_data_t
+ __aligned(sizeof(struct __call_single_data));
+
+/* total number of cpus in this system (may exceed NR_CPUS) */
+extern unsigned int total_cpus;
+
+int smp_call_function_single(int cpuid, smp_call_func_t func, void *info,
+ int wait);
+
+/*
+ * Call a function on all processors
+ */
+int on_each_cpu(smp_call_func_t func, void *info, int wait);
+
+/*
+ * Call a function on processors specified by mask, which might include
+ * the local one.
+ */
+void on_each_cpu_mask(const struct cpumask *mask, smp_call_func_t func,
+ void *info, bool wait);
+
+/*
+ * Call a function on each processor for which the supplied function
+ * cond_func returns a positive value. This may include the local
+ * processor.
+ */
+void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
+ smp_call_func_t func, void *info, bool wait,
+ gfp_t gfp_flags);
+
+int smp_call_function_single_async(int cpu, call_single_data_t *csd);
+
+#ifdef CONFIG_SMP
+
+#include <linux/preempt.h>
+#include <linux/kernel.h>
+#include <linux/compiler.h>
+#include <linux/thread_info.h>
+#include <asm/smp.h>
+
+/*
+ * main cross-CPU interfaces, handles INIT, TLB flush, STOP, etc.
+ * (defined in asm header):
+ */
+
+/*
+ * stops all CPUs but the current one:
+ */
+extern void smp_send_stop(void);
+
+/*
+ * sends a 'reschedule' event to another CPU:
+ */
+extern void smp_send_reschedule(int cpu);
+
+
+/*
+ * Prepare machine for booting other CPUs.
+ */
+extern void smp_prepare_cpus(unsigned int max_cpus);
+
+/*
+ * Bring a CPU up
+ */
+extern int __cpu_up(unsigned int cpunum, struct task_struct *tidle);
+
+/*
+ * Final polishing of CPUs
+ */
+extern void smp_cpus_done(unsigned int max_cpus);
+
+/*
+ * Call a function on all other processors
+ */
+int smp_call_function(smp_call_func_t func, void *info, int wait);
+void smp_call_function_many(const struct cpumask *mask,
+ smp_call_func_t func, void *info, bool wait);
+
+int smp_call_function_any(const struct cpumask *mask,
+ smp_call_func_t func, void *info, int wait);
+
+void kick_all_cpus_sync(void);
+void wake_up_all_idle_cpus(void);
+
+/*
+ * Generic and arch helpers
+ */
+void __init call_function_init(void);
+void generic_smp_call_function_single_interrupt(void);
+#define generic_smp_call_function_interrupt \
+ generic_smp_call_function_single_interrupt
+
+/*
+ * Mark the boot cpu "online" so that it can call console drivers in
+ * printk() and can access its per-cpu storage.
+ */
+void smp_prepare_boot_cpu(void);
+
+extern unsigned int setup_max_cpus;
+extern void __init setup_nr_cpu_ids(void);
+extern void __init smp_init(void);
+
+extern int __boot_cpu_id;
+
+static inline int get_boot_cpu_id(void)
+{
+ return __boot_cpu_id;
+}
+
+#else /* !SMP */
+
+static inline void smp_send_stop(void) { }
+
+/*
+ * These macros fold the SMP functionality into a single CPU system
+ */
+#define raw_smp_processor_id() 0
+static inline int up_smp_call_function(smp_call_func_t func, void *info)
+{
+ return 0;
+}
+#define smp_call_function(func, info, wait) \
+ (up_smp_call_function(func, info))
+
+static inline void smp_send_reschedule(int cpu) { }
+#define smp_prepare_boot_cpu() do {} while (0)
+#define smp_call_function_many(mask, func, info, wait) \
+ (up_smp_call_function(func, info))
+static inline void call_function_init(void) { }
+
+static inline int
+smp_call_function_any(const struct cpumask *mask, smp_call_func_t func,
+ void *info, int wait)
+{
+ return smp_call_function_single(0, func, info, wait);
+}
+
+static inline void kick_all_cpus_sync(void) { }
+static inline void wake_up_all_idle_cpus(void) { }
+
+#ifdef CONFIG_UP_LATE_INIT
+extern void __init up_late_init(void);
+static inline void smp_init(void) { up_late_init(); }
+#else
+static inline void smp_init(void) { }
+#endif
+
+static inline int get_boot_cpu_id(void)
+{
+ return 0;
+}
+
+#endif /* !SMP */
+
+/*
+ * smp_processor_id(): get the current CPU ID.
+ *
+ * if DEBUG_PREEMPT is enabled then we check whether it is
+ * used in a preemption-safe way. (smp_processor_id() is safe
+ * if it's used in a preemption-off critical section, or in
+ * a thread that is bound to the current CPU.)
+ *
+ * NOTE: raw_smp_processor_id() is for internal use only
+ * (smp_processor_id() is the preferred variant), but in rare
+ * instances it might also be used to turn off false positives
+ * (i.e. smp_processor_id() use that the debugging code reports but
+ * which use for some reason is legal). Don't use this to hack around
+ * the warning message, as your code might not work under PREEMPT.
+ */
+#ifdef CONFIG_DEBUG_PREEMPT
+ extern unsigned int debug_smp_processor_id(void);
+# define smp_processor_id() debug_smp_processor_id()
+#else
+# define smp_processor_id() raw_smp_processor_id()
+#endif
+
+#define get_cpu() ({ preempt_disable(); smp_processor_id(); })
+#define put_cpu() preempt_enable()
+
+/*
+ * Callback to arch code if there's nosmp or maxcpus=0 on the
+ * boot command line:
+ */
+extern void arch_disable_smp_support(void);
+
+extern void arch_enable_nonboot_cpus_begin(void);
+extern void arch_enable_nonboot_cpus_end(void);
+
+void smp_setup_processor_id(void);
+
+int smp_call_on_cpu(unsigned int cpu, int (*func)(void *), void *par,
+ bool phys);
+
+/* SMP core functions */
+int smpcfd_prepare_cpu(unsigned int cpu);
+int smpcfd_dead_cpu(unsigned int cpu);
+int smpcfd_dying_cpu(unsigned int cpu);
+
+#endif /* __LINUX_SMP_H */