/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_SMP_TYPES_H
#define __LINUX_SMP_TYPES_H

#include <linux/llist.h>

enum {
        CSD_FLAG_LOCK           = 0x01,

        IRQ_WORK_PENDING        = 0x01,
        IRQ_WORK_BUSY           = 0x02,
        IRQ_WORK_LAZY           = 0x04, /* No IPI, wait for tick */
        IRQ_WORK_HARD_IRQ       = 0x08, /* IRQ context on PREEMPT_RT */

        IRQ_WORK_CLAIMED        = (IRQ_WORK_PENDING | IRQ_WORK_BUSY),

        CSD_TYPE_ASYNC          = 0x00,
        CSD_TYPE_SYNC           = 0x10,
        CSD_TYPE_IRQ_WORK       = 0x20,
        CSD_TYPE_TTWU           = 0x30,

        CSD_FLAG_TYPE_MASK      = 0xF0,
};

/*
 * struct __call_single_node is the primary type on
 * smp.c:call_single_queue.
 *
 * flush_smp_call_function_queue() only reads the type from
 * __call_single_node::u_flags as a regular load, the above
 * (anonymous) enum defines all the bits of this word.
 *
 * Other bits are not modified until the type is known.
 *
 * CSD_TYPE_SYNC/ASYNC:
 *      struct {
 *              struct llist_node node;
 *              unsigned int flags;
 *              smp_call_func_t func;
 *              void *info;
 *      };
 *
 * CSD_TYPE_IRQ_WORK:
 *      struct {
 *              struct llist_node node;
 *              atomic_t flags;
 *              void (*func)(struct irq_work *);
 *      };
 *
 * CSD_TYPE_TTWU:
 *      struct {
 *              struct llist_node node;
 *              unsigned int flags;
 *      };
 *
 */

struct __call_single_node {
        struct llist_node       llist;
        union {
                unsigned int    u_flags;
                atomic_t        a_flags;
        };
#ifdef CONFIG_64BIT
        u16 src, dst;
#endif
};

#endif /* __LINUX_SMP_TYPES_H */