/*
   *
   * 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>

  #include <linux/interrupt.h>

  /*

   * Timeout for services such as KVP and fcopy.
   */
  #define HV_UTIL_TIMEOUT 30
  
  /*

   * Timeout for guest-host handshake for services.
   */

  #define HV_UTIL_NEGO_TIMEOUT 55

  /* Define synthetic interrupt controller flag constants. */
  #define HV_EVENT_FLAGS_COUNT		(256 * 8)
  #define HV_EVENT_FLAGS_LONG_COUNT	(256 / sizeof(unsigned long))

  /*
   * Timer configuration register.
   */
  union hv_timer_config {
  	u64 as_uint64;
  	struct {
  		u64 enable:1;
  		u64 periodic:1;
  		u64 lazy:1;
  		u64 auto_enable:1;
  		u64 reserved_z0:12;
  		u64 sintx:4;
  		u64 reserved_z1:44;
  	};
  };

  /* Define the synthetic interrupt controller event flags format. */
  union hv_synic_event_flags {

  	unsigned long flags[HV_EVENT_FLAGS_LONG_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];
  };

  #define HV_HYPERCALL_PARAM_ALIGN	sizeof(u64)

  /* Definition of the hv_post_message hypercall input structure. */
  struct hv_input_post_message {
  	union hv_connection_id connectionid;
  	u32 reserved;

  	u32 message_type;

  	u32 payload_size;
  	u64 payload[HV_MESSAGE_PAYLOAD_QWORD_COUNT];
  };

  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,
  };

  /*
   * Per cpu state for channel handling
   */
  struct hv_per_cpu_context {
  	void *synic_message_page;
  	void *synic_event_page;
  	/*
  	 * buffer to post messages to the host.
  	 */
  	void *post_msg_page;
  
  	/*
  	 * Starting with win8, we can take channel interrupts on any CPU;
  	 * we will manage the tasklet that handles events messages on a per CPU
  	 * basis.
  	 */

  	struct tasklet_struct msg_dpc;
  
  	/*
  	 * To optimize the mapping of relid to channel, maintain
  	 * per-cpu list of the channels based on their CPU affinity.
  	 */
  	struct list_head chan_list;
  	struct clock_event_device *clk_evt;
  };

  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 *tsc_page;

  
  	bool synic_initialized;

  	struct hv_per_cpu_context __percpu *cpu_context;

  	/*

  	 * To manage allocations in a NUMA node.
  	 * Array indexed by numa node ID.
  	 */
  	struct cpumask *hv_numa_map;

  };
  
  extern struct hv_context hv_context;

  /* Hv Interface */
  
  extern int hv_init(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 int hv_synic_alloc(void);
  
  extern void hv_synic_free(void);

  extern int hv_synic_init(unsigned int cpu);

  extern int hv_synic_cleanup(unsigned int cpu);

  extern void hv_synic_clockevents_cleanup(void);

  /* Interface */

  int hv_ringbuffer_init(struct hv_ring_buffer_info *ring_info,
  		       struct page *pages, u32 pagecnt);

  
  void hv_ringbuffer_cleanup(struct hv_ring_buffer_info *ring_info);

  int hv_ringbuffer_write(struct vmbus_channel *channel,

  			const struct kvec *kv_list, u32 kv_count);

  int hv_ringbuffer_read(struct vmbus_channel *channel,

  		       void *buffer, u32 buflen, u32 *buffer_actual_len,

  		       u64 *requestid, bool raw);

  /*
   * 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 {

  	/*
  	 * CPU on which the initial host contact was made.
  	 */
  	int connect_cpu;
  
  	atomic_t offer_in_progress;

  	enum vmbus_connect_state conn_state;
  
  	atomic_t next_gpadl_handle;

  	struct completion  unload_event;

  	/*
  	 * 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
  	 */

  	struct hv_monitor_page *monitor_pages[2];

  	struct list_head chn_msg_list;
  	spinlock_t channelmsg_lock;
  
  	/* List of channels */
  	struct list_head chn_list;

  	struct mutex channel_mutex;

  	/*
  	 * An offer message is handled first on the work_queue, and then
  	 * is further handled on handle_primary_chan_wq or
  	 * handle_sub_chan_wq.
  	 */

  	struct workqueue_struct *work_queue;

  	struct workqueue_struct *handle_primary_chan_wq;
  	struct workqueue_struct *handle_sub_chan_wq;

  };
  
  
  struct vmbus_msginfo {
  	/* Bookkeeping stuff */
  	struct list_head msglist_entry;
  
  	/* The message itself */
  	unsigned char msg[0];
  };
  
  
  extern struct vmbus_connection vmbus_connection;

  static inline void vmbus_send_interrupt(u32 relid)
  {
  	sync_set_bit(relid, vmbus_connection.send_int_page);
  }

  enum vmbus_message_handler_type {
  	/* The related handler can sleep. */
  	VMHT_BLOCKING = 0,
  
  	/* The related handler must NOT sleep. */
  	VMHT_NON_BLOCKING = 1,
  };
  
  struct vmbus_channel_message_table_entry {
  	enum vmbus_channel_message_type message_type;
  	enum vmbus_message_handler_type handler_type;
  	void (*message_handler)(struct vmbus_channel_message_header *msg);
  };

  extern const struct vmbus_channel_message_table_entry

  	channel_message_table[CHANNELMSG_COUNT];

  /* General vmbus interface */

  struct hv_device *vmbus_device_create(const uuid_le *type,
  				      const 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);

  struct vmbus_channel *relid2channel(u32 relid);

  void vmbus_free_channels(void);

  
  /* Connection interface */
  
  int vmbus_connect(void);

  void vmbus_disconnect(void);

  int vmbus_post_msg(void *buffer, size_t buflen, bool can_sleep);

  void vmbus_on_event(unsigned long data);

  void vmbus_on_msg_dpc(unsigned long data);

  int hv_kvp_init(struct hv_util_service *srv);

  void hv_kvp_deinit(void);

  void hv_kvp_onchannelcallback(void *context);

  int hv_vss_init(struct hv_util_service *srv);

  void hv_vss_deinit(void);

  void hv_vss_onchannelcallback(void *context);

  int hv_fcopy_init(struct hv_util_service *srv);

  void hv_fcopy_deinit(void);

  void hv_fcopy_onchannelcallback(void *context);

  void vmbus_initiate_unload(bool crash);

  static inline void hv_poll_channel(struct vmbus_channel *channel,
  				   void (*cb)(void *))
  {
  	if (!channel)
  		return;

  	if (in_interrupt() && (channel->target_cpu == smp_processor_id())) {
  		cb(channel);
  		return;
  	}

  	smp_call_function_single(channel->target_cpu, cb, channel, true);

  }

  enum hvutil_device_state {
  	HVUTIL_DEVICE_INIT = 0,  /* driver is loaded, waiting for userspace */
  	HVUTIL_READY,            /* userspace is registered */
  	HVUTIL_HOSTMSG_RECEIVED, /* message from the host was received */
  	HVUTIL_USERSPACE_REQ,    /* request to userspace was sent */
  	HVUTIL_USERSPACE_RECV,   /* reply from userspace was received */
  	HVUTIL_DEVICE_DYING,     /* driver unload is in progress */
  };

  #endif /* _HYPERV_VMBUS_H */