/* SPDX-License-Identifier: GPL-2.0+ */
/*
 * linux/drivers/misc/ibmvmc.h
 *
 * IBM Power Systems Virtual Management Channel Support.
 *
 * Copyright (c) 2004, 2018 IBM Corp.
 *   Dave Engebretsen engebret@us.ibm.com
 *   Steven Royer seroyer@linux.vnet.ibm.com
 *   Adam Reznechek adreznec@linux.vnet.ibm.com
 *   Bryant G. Ly <bryantly@linux.vnet.ibm.com>
 */
#ifndef IBMVMC_H
#define IBMVMC_H

#include <linux/types.h>
#include <linux/cdev.h>

#include <asm/vio.h>

#define IBMVMC_PROTOCOL_VERSION    0x0101

#define MIN_BUF_POOL_SIZE 16
#define MIN_HMCS          1
#define MIN_MTU           4096
#define MAX_BUF_POOL_SIZE 64
#define MAX_HMCS          2
#define MAX_MTU           (4 * 4096)
#define DEFAULT_BUF_POOL_SIZE 32
#define DEFAULT_HMCS          1
#define DEFAULT_MTU           4096
#define HMC_ID_LEN        32

#define VMC_INVALID_BUFFER_ID 0xFFFF

/* ioctl numbers */
#define VMC_BASE             0xCC
#define VMC_IOCTL_SETHMCID   _IOW(VMC_BASE, 0x00, unsigned char *)
#define VMC_IOCTL_QUERY      _IOR(VMC_BASE, 0x01, struct ibmvmc_query_struct)
#define VMC_IOCTL_REQUESTVMC _IOR(VMC_BASE, 0x02, u32)

#define VMC_MSG_CAP          0x01
#define VMC_MSG_CAP_RESP     0x81
#define VMC_MSG_OPEN         0x02
#define VMC_MSG_OPEN_RESP    0x82
#define VMC_MSG_CLOSE        0x03
#define VMC_MSG_CLOSE_RESP   0x83
#define VMC_MSG_ADD_BUF      0x04
#define VMC_MSG_ADD_BUF_RESP 0x84
#define VMC_MSG_REM_BUF      0x05
#define VMC_MSG_REM_BUF_RESP 0x85
#define VMC_MSG_SIGNAL       0x06

#define VMC_MSG_SUCCESS 0
#define VMC_MSG_INVALID_HMC_INDEX 1
#define VMC_MSG_INVALID_BUFFER_ID 2
#define VMC_MSG_CLOSED_HMC        3
#define VMC_MSG_INTERFACE_FAILURE 4
#define VMC_MSG_NO_BUFFER         5

#define VMC_BUF_OWNER_ALPHA 0
#define VMC_BUF_OWNER_HV    1

enum ibmvmc_states {
        ibmvmc_state_sched_reset  = -1,
        ibmvmc_state_initial      = 0,
        ibmvmc_state_crqinit      = 1,
        ibmvmc_state_capabilities = 2,
        ibmvmc_state_ready        = 3,
        ibmvmc_state_failed       = 4,
};

enum ibmhmc_states {
        /* HMC connection not established */
        ibmhmc_state_free    = 0,

        /* HMC connection established (open called) */
        ibmhmc_state_initial = 1,

        /* open msg sent to HV, due to ioctl(1) call */
        ibmhmc_state_opening = 2,

        /* HMC connection ready, open resp msg from HV */
        ibmhmc_state_ready   = 3,

        /* HMC connection failure */
        ibmhmc_state_failed  = 4,
};

struct ibmvmc_buffer {
        u8 valid;       /* 1 when DMA storage allocated to buffer          */
        u8 free;        /* 1 when buffer available for the Alpha Partition */
        u8 owner;
        u16 id;
        u32 size;
        u32 msg_len;
        dma_addr_t dma_addr_local;
        dma_addr_t dma_addr_remote;
        void *real_addr_local;
};

struct ibmvmc_admin_crq_msg {
        u8 valid;       /* RPA Defined           */
        u8 type;        /* ibmvmc msg type       */
        u8 status;      /* Response msg status. Zero is success and on failure,
                         * either 1 - General Failure, or 2 - Invalid Version is
                         * returned.
                         */
        u8 rsvd[2];
        u8 max_hmc;     /* Max # of independent HMC connections supported */
        __be16 pool_size;       /* Maximum number of buffers supported per HMC
                                 * connection
                                 */
        __be32 max_mtu;         /* Maximum message size supported (bytes) */
        __be16 crq_size;        /* # of entries available in the CRQ for the
                                 * source partition. The target partition must
                                 * limit the number of outstanding messages to
                                 * one half or less.
                                 */
        __be16 version; /* Indicates the code level of the management partition
                         * or the hypervisor with the high-order byte
                         * indicating a major version and the low-order byte
                         * indicating a minor version.
                         */
};

struct ibmvmc_crq_msg {
        u8 valid;     /* RPA Defined           */
        u8 type;      /* ibmvmc msg type       */
        u8 status;    /* Response msg status   */
        union {
                u8 rsvd;  /* Reserved              */
                u8 owner;
        } var1;
        u8 hmc_session; /* Session Identifier for the current VMC connection */
        u8 hmc_index;   /* A unique HMC Idx would be used if multiple management
                         * applications running concurrently were desired
                         */
        union {
                __be16 rsvd;
                __be16 buffer_id;
        } var2;
        __be32 rsvd;
        union {
                __be32 rsvd;
                __be32 lioba;
                __be32 msg_len;
        } var3;
};

/* an RPA command/response transport queue */
struct crq_queue {
        struct ibmvmc_crq_msg *msgs;
        int size, cur;
        dma_addr_t msg_token;
        spinlock_t lock;
};

/* VMC server adapter settings */
struct crq_server_adapter {
        struct device *dev;
        struct crq_queue queue;
        u32 liobn;
        u32 riobn;
        struct tasklet_struct work_task;
        wait_queue_head_t reset_wait_queue;
        struct task_struct *reset_task;
};

/* Driver wide settings */
struct ibmvmc_struct {
        u32 state;
        u32 max_mtu;
        u32 max_buffer_pool_size;
        u32 max_hmc_index;
        struct crq_server_adapter *adapter;
        struct cdev cdev;
        u32 vmc_drc_index;
};

struct ibmvmc_file_session;

/* Connection specific settings */
struct ibmvmc_hmc {
        u8 session;
        u8 index;
        u32 state;
        struct crq_server_adapter *adapter;
        spinlock_t lock;
        unsigned char hmc_id[HMC_ID_LEN];
        struct ibmvmc_buffer buffer[MAX_BUF_POOL_SIZE];
        unsigned short queue_outbound_msgs[MAX_BUF_POOL_SIZE];
        int queue_head, queue_tail;
        struct ibmvmc_file_session *file_session;
};

struct ibmvmc_file_session {
        struct file *file;
        struct ibmvmc_hmc *hmc;
        bool valid;
};

struct ibmvmc_query_struct {
        int have_vmc;
        int state;
        int vmc_drc_index;
};

#endif /* __IBMVMC_H */