/*
 *
 * Copyright (c) 2011, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 *   K. Y. Srinivasan <kys@microsoft.com>
 *
 */

#ifndef _HYPERV_VMBUS_H
#define _HYPERV_VMBUS_H

#include <linux/list.h>
#include <asm/sync_bitops.h>
#include <linux/atomic.h>
#include <linux/hyperv.h>

/*
 * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
 * is set by CPUID(HVCPUID_VERSION_FEATURES).
 */
enum hv_cpuid_function {
        HVCPUID_VERSION_FEATURES                = 0x00000001,
        HVCPUID_VENDOR_MAXFUNCTION              = 0x40000000,
        HVCPUID_INTERFACE                       = 0x40000001,

        /*
         * The remaining functions depend on the value of
         * HVCPUID_INTERFACE
         */
        HVCPUID_VERSION                 = 0x40000002,
        HVCPUID_FEATURES                        = 0x40000003,
        HVCPUID_ENLIGHTENMENT_INFO      = 0x40000004,
        HVCPUID_IMPLEMENTATION_LIMITS           = 0x40000005,
};

/* Define version of the synthetic interrupt controller. */
#define HV_SYNIC_VERSION                (1)

/* Define the expected SynIC version. */
#define HV_SYNIC_VERSION_1              (0x1)

/* Define synthetic interrupt controller message constants. */
#define HV_MESSAGE_SIZE                 (256)
#define HV_MESSAGE_PAYLOAD_BYTE_COUNT   (240)
#define HV_MESSAGE_PAYLOAD_QWORD_COUNT  (30)
#define HV_ANY_VP                       (0xFFFFFFFF)

/* Define synthetic interrupt controller flag constants. */
#define HV_EVENT_FLAGS_COUNT            (256 * 8)
#define HV_EVENT_FLAGS_BYTE_COUNT       (256)
#define HV_EVENT_FLAGS_DWORD_COUNT      (256 / sizeof(u32))

/* Define hypervisor message types. */
enum hv_message_type {
        HVMSG_NONE                      = 0x00000000,

        /* Memory access messages. */
        HVMSG_UNMAPPED_GPA              = 0x80000000,
        HVMSG_GPA_INTERCEPT             = 0x80000001,

        /* Timer notification messages. */
        HVMSG_TIMER_EXPIRED                     = 0x80000010,

        /* Error messages. */
        HVMSG_INVALID_VP_REGISTER_VALUE = 0x80000020,
        HVMSG_UNRECOVERABLE_EXCEPTION   = 0x80000021,
        HVMSG_UNSUPPORTED_FEATURE               = 0x80000022,

        /* Trace buffer complete messages. */
        HVMSG_EVENTLOG_BUFFERCOMPLETE   = 0x80000040,

        /* Platform-specific processor intercept messages. */
        HVMSG_X64_IOPORT_INTERCEPT              = 0x80010000,
        HVMSG_X64_MSR_INTERCEPT         = 0x80010001,
        HVMSG_X64_CPUID_INTERCEPT               = 0x80010002,
        HVMSG_X64_EXCEPTION_INTERCEPT   = 0x80010003,
        HVMSG_X64_APIC_EOI                      = 0x80010004,
        HVMSG_X64_LEGACY_FP_ERROR               = 0x80010005
};

/* Define the number of synthetic interrupt sources. */
#define HV_SYNIC_SINT_COUNT             (16)
#define HV_SYNIC_STIMER_COUNT           (4)

/* Define invalid partition identifier. */
#define HV_PARTITION_ID_INVALID         ((u64)0x0)

/* Define port identifier type. */
union hv_port_id {
        u32 asu32;
        struct {
                u32 id:24;
                u32 reserved:8;
        } u ;
};

/* Define port type. */
enum hv_port_type {
        HVPORT_MSG      = 1,
        HVPORT_EVENT            = 2,
        HVPORT_MONITOR  = 3
};

/* Define port information structure. */
struct hv_port_info {
        enum hv_port_type port_type;
        u32 padding;
        union {
                struct {
                        u32 target_sint;
                        u32 target_vp;
                        u64 rsvdz;
                } message_port_info;
                struct {
                        u32 target_sint;
                        u32 target_vp;
                        u16 base_flag_bumber;
                        u16 flag_count;
                        u32 rsvdz;
                } event_port_info;
                struct {
                        u64 monitor_address;
                        u64 rsvdz;
                } monitor_port_info;
        };
};

struct hv_connection_info {
        enum hv_port_type port_type;
        u32 padding;
        union {
                struct {
                        u64 rsvdz;
                } message_connection_info;
                struct {
                        u64 rsvdz;
                } event_connection_info;
                struct {
                        u64 monitor_address;
                } monitor_connection_info;
        };
};

/* Define synthetic interrupt controller message flags. */
union hv_message_flags {
        u8 asu8;
        struct {
                u8 msg_pending:1;
                u8 reserved:7;
        };
};

/* Define synthetic interrupt controller message header. */
struct hv_message_header {
        enum hv_message_type message_type;
        u8 payload_size;
        union hv_message_flags message_flags;
        u8 reserved[2];
        union {
                u64 sender;
                union hv_port_id port;
        };
};

/* Define timer message payload structure. */
struct hv_timer_message_payload {
        u32 timer_index;
        u32 reserved;
        u64 expiration_time;    /* When the timer expired */
        u64 delivery_time;      /* When the message was delivered */
};

/* Define synthetic interrupt controller message format. */
struct hv_message {
        struct hv_message_header header;
        union {
                u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
        } u ;
};

/* Define the number of message buffers associated with each port. */
#define HV_PORT_MESSAGE_BUFFER_COUNT    (16)

/* Define the synthetic interrupt message page layout. */
struct hv_message_page {
        struct hv_message sint_message[HV_SYNIC_SINT_COUNT];
};

/* Define the synthetic interrupt controller event flags format. */
union hv_synic_event_flags {
        u8 flags8[HV_EVENT_FLAGS_BYTE_COUNT];
        u32 flags32[HV_EVENT_FLAGS_DWORD_COUNT];
};

/* Define the synthetic interrupt flags page layout. */
struct hv_synic_event_flags_page {
        union hv_synic_event_flags sintevent_flags[HV_SYNIC_SINT_COUNT];
};

/* Define SynIC control register. */
union hv_synic_scontrol {
        u64 as_uint64;
        struct {
                u64 enable:1;
                u64 reserved:63;
        };
};

/* Define synthetic interrupt source. */
union hv_synic_sint {
        u64 as_uint64;
        struct {
                u64 vector:8;
                u64 reserved1:8;
                u64 masked:1;
                u64 auto_eoi:1;
                u64 reserved2:46;
        };
};

/* Define the format of the SIMP register */
union hv_synic_simp {
        u64 as_uint64;
        struct {
                u64 simp_enabled:1;
                u64 preserved:11;
                u64 base_simp_gpa:52;
        };
};

/* Define the format of the SIEFP register */
union hv_synic_siefp {
        u64 as_uint64;
        struct {
                u64 siefp_enabled:1;
                u64 preserved:11;
                u64 base_siefp_gpa:52;
        };
};

/* Definitions for the monitored notification facility */
union hv_monitor_trigger_group {
        u64 as_uint64;
        struct {
                u32 pending;
                u32 armed;
        };
};

struct hv_monitor_parameter {
        union hv_connection_id connectionid;
        u16 flagnumber;
        u16 rsvdz;
};

union hv_monitor_trigger_state {
        u32 asu32;

        struct {
                u32 group_enable:4;
                u32 rsvdz:28;
        };
};

/* struct hv_monitor_page Layout */
/* ------------------------------------------------------ */
/* | 0   | TriggerState (4 bytes) | Rsvd1 (4 bytes)     | */
/* | 8   | TriggerGroup[0]                              | */
/* | 10  | TriggerGroup[1]                              | */
/* | 18  | TriggerGroup[2]                              | */
/* | 20  | TriggerGroup[3]                              | */
/* | 28  | Rsvd2[0]                                     | */
/* | 30  | Rsvd2[1]                                     | */
/* | 38  | Rsvd2[2]                                     | */
/* | 40  | NextCheckTime[0][0]    | NextCheckTime[0][1] | */
/* | ...                                                | */
/* | 240 | Latency[0][0..3]                             | */
/* | 340 | Rsvz3[0]                                     | */
/* | 440 | Parameter[0][0]                              | */
/* | 448 | Parameter[0][1]                              | */
/* | ...                                                | */
/* | 840 | Rsvd4[0]                                     | */
/* ------------------------------------------------------ */
struct hv_monitor_page {
        union hv_monitor_trigger_state trigger_state;
        u32 rsvdz1;

        union hv_monitor_trigger_group trigger_group[4];
        u64 rsvdz2[3];

        s32 next_checktime[4][32];

        u16 latency[4][32];
        u64 rsvdz3[32];

        struct hv_monitor_parameter parameter[4][32];

        u8 rsvdz4[1984];
};

/* Declare the various hypercall operations. */
enum hv_call_code {
        HVCALL_POST_MESSAGE     = 0x005c,
        HVCALL_SIGNAL_EVENT     = 0x005d,
};

/* Definition of the hv_post_message hypercall input structure. */
struct hv_input_post_message {
        union hv_connection_id connectionid;
        u32 reserved;
        enum hv_message_type message_type;
        u32 payload_size;
        u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
};

/*
 * Versioning definitions used for guests reporting themselves to the
 * hypervisor, and visa versa.
 */

/* Version info reported by guest OS's */
enum hv_guest_os_vendor {
        HVGUESTOS_VENDOR_MICROSOFT      = 0x0001
};

enum hv_guest_os_microsoft_ids {
        HVGUESTOS_MICROSOFT_UNDEFINED   = 0x00,
        HVGUESTOS_MICROSOFT_MSDOS               = 0x01,
        HVGUESTOS_MICROSOFT_WINDOWS3X   = 0x02,
        HVGUESTOS_MICROSOFT_WINDOWS9X   = 0x03,
        HVGUESTOS_MICROSOFT_WINDOWSNT   = 0x04,
        HVGUESTOS_MICROSOFT_WINDOWSCE   = 0x05
};

/*
 * Declare the MSR used to identify the guest OS.
 */
#define HV_X64_MSR_GUEST_OS_ID  0x40000000

union hv_x64_msr_guest_os_id_contents {
        u64 as_uint64;
        struct {
                u64 build_number:16;
                u64 service_version:8; /* Service Pack, etc. */
                u64 minor_version:8;
                u64 major_version:8;
                u64 os_id:8; /* enum hv_guest_os_microsoft_ids (if Vendor=MS) */
                u64 vendor_id:16; /* enum hv_guest_os_vendor */
        };
};

/*
 * Declare the MSR used to setup pages used to communicate with the hypervisor.
 */
#define HV_X64_MSR_HYPERCALL    0x40000001

union hv_x64_msr_hypercall_contents {
        u64 as_uint64;
        struct {
                u64 enable:1;
                u64 reserved:11;
                u64 guest_physical_address:52;
        };
};


enum {
        VMBUS_MESSAGE_CONNECTION_ID     = 1,
        VMBUS_MESSAGE_PORT_ID           = 1,
        VMBUS_EVENT_CONNECTION_ID       = 2,
        VMBUS_EVENT_PORT_ID             = 2,
        VMBUS_MONITOR_CONNECTION_ID     = 3,
        VMBUS_MONITOR_PORT_ID           = 3,
        VMBUS_MESSAGE_SINT              = 2,
};

/* #defines */

#define HV_PRESENT_BIT                  0x80000000

/*
 * The guest OS needs to register the guest ID with the hypervisor.
 * The guest ID is a 64 bit entity and the structure of this ID is
 * specified in the Hyper-V specification:
 *
 * http://msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
 *
 * While the current guideline does not specify how Linux guest ID(s)
 * need to be generated, our plan is to publish the guidelines for
 * Linux and other guest operating systems that currently are hosted
 * on Hyper-V. The implementation here conforms to this yet
 * unpublished guidelines.
 *
 *
 * Bit(s)
 * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
 * 62:56 - Os Type; Linux is 0x100
 * 55:48 - Distro specific identification
 * 47:16 - Linux kernel version number
 * 15:0  - Distro specific identification
 *
 *
 */

#define HV_LINUX_VENDOR_ID              0x8100

/*
 * Generate the guest ID based on the guideline described above.
 */

static inline  __u64 generate_guest_id(__u8 d_info1, __u32 kernel_version,
                                        __u16 d_info2)
{
        __u64 guest_id = 0;

        guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
        guest_id |= (((__u64)(d_info1)) << 48);
        guest_id |= (((__u64)(kernel_version)) << 16);
        guest_id |= ((__u64)(d_info2));

        return guest_id;
}


#define HV_CPU_POWER_MANAGEMENT         (1 << 0)
#define HV_RECOMMENDATIONS_MAX          4

#define HV_X64_MAX                      5
#define HV_CAPS_MAX                     8


#define HV_HYPERCALL_PARAM_ALIGN        sizeof(u64)


/* Service definitions */

#define HV_SERVICE_PARENT_PORT                          (0)
#define HV_SERVICE_PARENT_CONNECTION                    (0)

#define HV_SERVICE_CONNECT_RESPONSE_SUCCESS             (0)
#define HV_SERVICE_CONNECT_RESPONSE_INVALID_PARAMETER   (1)
#define HV_SERVICE_CONNECT_RESPONSE_UNKNOWN_SERVICE     (2)
#define HV_SERVICE_CONNECT_RESPONSE_CONNECTION_REJECTED (3)

#define HV_SERVICE_CONNECT_REQUEST_MESSAGE_ID           (1)
#define HV_SERVICE_CONNECT_RESPONSE_MESSAGE_ID          (2)
#define HV_SERVICE_DISCONNECT_REQUEST_MESSAGE_ID        (3)
#define HV_SERVICE_DISCONNECT_RESPONSE_MESSAGE_ID       (4)
#define HV_SERVICE_MAX_MESSAGE_ID                               (4)

#define HV_SERVICE_PROTOCOL_VERSION (0x0010)
#define HV_CONNECT_PAYLOAD_BYTE_COUNT 64

/* #define VMBUS_REVISION_NUMBER        6 */

/* Our local vmbus's port and connection id. Anything >0 is fine */
/* #define VMBUS_PORT_ID                11 */

/* 628180B8-308D-4c5e-B7DB-1BEB62E62EF4 */
static const uuid_le VMBUS_SERVICE_ID = {
        .b = {
                0xb8, 0x80, 0x81, 0x62, 0x8d, 0x30, 0x5e, 0x4c,
                0xb7, 0xdb, 0x1b, 0xeb, 0x62, 0xe6, 0x2e, 0xf4
        },
};



struct hv_context {
        /* We only support running on top of Hyper-V
        * So at this point this really can only contain the Hyper-V ID
        */
        u64 guestid;

        void *hypercall_page;

        bool synic_initialized;

        void *synic_message_page[NR_CPUS];
        void *synic_event_page[NR_CPUS];
        /*
         * Hypervisor's notion of virtual processor ID is different from
         * Linux' notion of CPU ID. This information can only be retrieved
         * in the context of the calling CPU. Setup a map for easy access
         * to this information:
         *
         * vp_index[a] is the Hyper-V's processor ID corresponding to
         * Linux cpuid 'a'.
         */
        u32 vp_index[NR_CPUS];
        /*
         * Starting with win8, we can take channel interrupts on any CPU;
         * we will manage the tasklet that handles events on a per CPU
         * basis.
         */
        struct tasklet_struct *event_dpc[NR_CPUS];
};

extern struct hv_context hv_context;


/* Hv Interface */

extern int hv_init(void);

extern void hv_cleanup(void);

extern int hv_post_message(union hv_connection_id connection_id,
                         enum hv_message_type message_type,
                         void *payload, size_t payload_size);

extern u16 hv_signal_event(void *con_id);

extern void hv_synic_init(void *irqarg);

extern void hv_synic_cleanup(void *arg);

/*
 * Host version information.
 */
extern unsigned int host_info_eax;
extern unsigned int host_info_ebx;
extern unsigned int host_info_ecx;
extern unsigned int host_info_edx;

/* Interface */


int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info, void *buffer,
                   u32 buflen);

void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);

int hv_ringbuffer_write(struct hv_ring_buffer_info *ring_info,
                    struct scatterlist *sglist,
                    u32 sgcount, bool *signal);

int hv_ringbuffer_peek(struct hv_ring_buffer_info *ring_info, void *buffer,
                   u32 buflen);

int hv_ringbuffer_read(struct hv_ring_buffer_info *ring_info,
                   void *buffer,
                   u32 buflen,
                   u32 offset, bool *signal);


void hv_ringbuffer_get_debuginfo(struct hv_ring_buffer_info *ring_info,
                            struct hv_ring_buffer_debug_info *debug_info);

void hv_begin_read(struct hv_ring_buffer_info *rbi);

u32 hv_end_read(struct hv_ring_buffer_info *rbi);

/*
 * Maximum channels is determined by the size of the interrupt page
 * which is PAGE_SIZE. 1/2 of PAGE_SIZE is for send endpoint interrupt
 * and the other is receive endpoint interrupt
 */
#define MAX_NUM_CHANNELS        ((PAGE_SIZE >> 1) << 3) /* 16348 channels */

/* The value here must be in multiple of 32 */
/* TODO: Need to make this configurable */
#define MAX_NUM_CHANNELS_SUPPORTED      256


enum vmbus_connect_state {
        DISCONNECTED,
        CONNECTING,
        CONNECTED,
        DISCONNECTING
};

#define MAX_SIZE_CHANNEL_MESSAGE        HV_MESSAGE_PAYLOAD_BYTE_COUNT

struct vmbus_connection {
        enum vmbus_connect_state conn_state;

        atomic_t next_gpadl_handle;

        /*
         * Represents channel interrupts. Each bit position represents a
         * channel.  When a channel sends an interrupt via VMBUS, it finds its
         * bit in the sendInterruptPage, set it and calls Hv to generate a port
         * event. The other end receives the port event and parse the
         * recvInterruptPage to see which bit is set
         */
        void *int_page;
        void *send_int_page;
        void *recv_int_page;

        /*
         * 2 pages - 1st page for parent->child notification and 2nd
         * is child->parent notification
         */
        void *monitor_pages;
        struct list_head chn_msg_list;
        spinlock_t channelmsg_lock;

        /* List of channels */
        struct list_head chn_list;
        spinlock_t channel_lock;

        struct workqueue_struct *work_queue;
};


struct vmbus_msginfo {
        /* Bookkeeping stuff */
        struct list_head msglist_entry;

        /* The message itself */
        unsigned char msg[0];
};


extern struct vmbus_connection vmbus_connection;

/* General vmbus interface */

struct hv_device *vmbus_device_create(uuid_le *type,
                                         uuid_le *instance,
                                         struct vmbus_channel *channel);

int vmbus_device_register(struct hv_device *child_device_obj);
void vmbus_device_unregister(struct hv_device *device_obj);

/* static void */
/* VmbusChildDeviceDestroy( */
/* struct hv_device *); */

struct vmbus_channel *relid2channel(u32 relid);

void vmbus_free_channels(void);

/* Connection interface */

int vmbus_connect(void);

int vmbus_post_msg(void *buffer, size_t buflen);

int vmbus_set_event(struct vmbus_channel *channel);

void vmbus_on_event(unsigned long data);


#endif /* _HYPERV_VMBUS_H */