/*
 * cluster.h - Cluster-Manager definition
 *
 * authors  Ghassan Almaless       (2008,2009,2010,2011,2012)
 *          Mohamed Lamine Karaoui (2015)
 *          Alain Greiner          (2016,2017,2018,2019,2020)
 *
 * Copyright (c) UPMC Sorbonne Universites
 *
 * This file is part of ALMOS-MKH.
 *
 * ALMOS-MKH is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2.0 of the License.
 *
 * ALMOS-MKH is distributed in the hope that 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 ALMOS-MKH; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef _CLUSTER_H_
#define _CLUSTER_H_

#include <kernel_config.h>
#include <hal_kernel_types.h>
#include <bits.h>
#include <queuelock.h>
#include <remote_queuelock.h>
#include <list.h>
#include <xlist.h>
#include <dqdt.h>
#include <kmem.h>
#include <hal_atomic.h>
#include <ppm.h>
#include <kcm.h>
#include <rpc.h>
#include <core.h>
#include <process.h>

/**** Forward declarations  ****/

struct core_s;
struct process_s;


/*******************************************************************************************
 * This structure defines the process manager, that is part of the cluster manager.
 * For any process P, the process descriptor is replicated in all clusters containing
 * at least one thread of process P, but only the "reference" cluster descriptor contains
 * the reference (complete) GPT, VSL, and FDT structures. 
 * The "owner" cluster K is in charge to allocate a lpid (local process index), 
 * to the owned processes, and to register the "reference" cluster for these processes.
 *
 * Warning : the "owner" cluster, and the "reference" cluster can be different clusters.
 *
 * The process manager of a cluster K maintains three sets of process descriptors:
 *
 * 1) pref_tbl[] is an array indexed by lpid. There is one entry per owned process.
 *    Each entry contains an extended pointer on the reference process descriptor.
 *
 * 2) The local_root is the root of the local list of all process descriptors in cluster K.
 *    A process descriptor P is present in K, as soon as P has a thread in cluster K.
 *    We use an xlist, because this list can be traversed by remote threads.
 *
 * 3) The copies_root[] array is indexed by lpid. There is one entry per owned process,
 *    and each each entry contains the root of the xlist of copies for this process.
 $    We use an xlist, because process copies are distributed in all clusters. 
 ******************************************************************************************/

typedef struct process_manager_s
{
	xptr_t             pref_tbl[CONFIG_MAX_PROCESS_PER_CLUSTER];  /*! owned  processes    */
	queuelock_t        pref_lock;              /*! lock protecting pref_tbl               */
    uint32_t           pref_nr;                /*! number of processes owned by cluster   */

    xlist_entry_t      local_root;            /*! root of list of process in cluster      */
    remote_queuelock_t local_lock;            /*! lock protecting local list              */
    uint32_t           local_nr;              /*! number of process in cluster            */

    xlist_entry_t      copies_root[CONFIG_MAX_PROCESS_PER_CLUSTER];  /*! roots of lists   */
    remote_queuelock_t copies_lock[CONFIG_MAX_PROCESS_PER_CLUSTER];  /*! one  per list    */
    uint32_t           copies_nr[CONFIG_MAX_PROCESS_PER_CLUSTER];    /*! number of copie  */
}
pmgr_t;

/*******************************************************************************************
 * This structure defines a cluster manager.
 * It contains both global platform information, and cluster specific resources
 * controled by the local kernel instance.
 ******************************************************************************************/

typedef struct cluster_s
{

    // global parameters
    uint32_t        paddr_width;       /*! numer of bits in physical address              */
    uint32_t        x_width;           /*! number of bits to code x_size  (can be 0)      */
    uint32_t        y_width;           /*! number of bits to code y_size  (can be 0)      */
    uint32_t        x_size;            /*! number of clusters in a row    (can be 1)      */
    uint32_t        y_size;            /*! number of clusters in a column (can be 1)      */
    uint32_t        io_cxy;            /*! io cluster identifier                          */
    uint32_t        sys_clk;           /*! system_clock frequency (in Hertz)              */
    uint32_t        dqdt_root_level;   /*! index of root node in dqdt_tbl[]               */
    uint32_t        nb_txt_channels;   /*! number of TXT channels                         */
    uint32_t        nb_nic_channels;   /*! number of NIC channels                         */
    uint32_t        nb_ioc_channels;   /*! number of IOC channels                         */
    uint32_t        nb_fbf_channels;   /*! number of FBF channels                         */

    // number of cores for each cluster in the mesh
    uint8_t         cluster_info[CONFIG_MAX_CLUSTERS_X][CONFIG_MAX_CLUSTERS_Y];

    // local parameters
    uint32_t        cores_nr;          /*! actual number of cores in cluster              */
    uint32_t        ram_size;          /*! physical memory size                           */
    uint32_t        ram_base;          /*! physical memory base (local address)           */

	core_t          core_tbl[CONFIG_MAX_LOCAL_CORES];    /*! embedded cores               */

    list_entry_t    dev_root;          /*! root of list of devices in cluster             */

    // physical memory allocators: one PPM and severa KCM
    ppm_t           ppm;
    kcm_t           kcm[CONFIG_PPM_PAGE_ORDER - CONFIG_CACHE_LINE_ORDER];

    // RPC
    remote_fifo_t   rpc_fifo[CONFIG_MAX_LOCAL_CORES];    /*! one RPC FIFO per core        */
    uint32_t        rpc_threads[CONFIG_MAX_LOCAL_CORES]; /*! RPC threads per core         */

    // DQDT
    dqdt_node_t     dqdt_tbl[CONFIG_DQDT_LEVELS_NR];     /*! embedded DQDT nodes          */

    xptr_t          dqdt_root_xp;      /*! extended pointer on DQDT root node             */

    // Local process manager
    pmgr_t          pmgr;              /*! embedded process manager                       */

    void          * pic_extend;        /*! PIC implementation specific extension          */
}
cluster_t;

/******************************************************************************************
 * This global variable is allocated in the kernel_init.c file.
 * There is one cluster_manager per cluster, with the same local address,
 * but different content, in all clusters containing a kernel instance.
 *****************************************************************************************/

extern cluster_t cluster_manager;

/******************************************************************************************
 * This macro returns a local pointer on the local cluster manager.
 *****************************************************************************************/

#define LOCAL_CLUSTER    (&cluster_manager)

/******************************************************************************************
 * These two functions initialise the local cluster manager from information found
 * in the local boot-info structure <info> build by the boot-loader.
 * 1) the cluster_info_init() function is called first, to initialize the structural
 *    constants, including the cluster_info[x][y] array.
 *    It cannot use the TXT0 kernel terminal.
 * 2) the cluster_manager_init() function initializes various complex structures:
 *    - the local DQDT nodes,
 *    - the PPM, KHM, and KCM allocators,
 *    - the local core descriptors,
 *    - the local RPC FIFO,
 *    - the process manager.
 *    It can use the TXT0 kernel terminal.
 ******************************************************************************************
 * @ info : pointer on the local boot_info_t structure build by the bootloader.
 *****************************************************************************************/
void    cluster_info_init( boot_info_t * info );
error_t cluster_manager_init( boot_info_t * info );

/******************************************************************************************
 * This debug function displays the current values stored in the cluster_info[][] array
 * of a remote cluster identified by the <cxy> argument.
 * It can be called by a thread running in any cluster.
 ******************************************************************************************
 * @ cxy   : remote cluster identifier.
 *****************************************************************************************/
void cluster_info_display( cxy_t  cxy );

/******************************************************************************************
 * This function access the local cluster_info[][] array and returns true when the 
 * cluster identified by the <cxy> argument is active (contains a kernel instance).
 ******************************************************************************************
 * @ cxy   : checked cluster identifier.
 * @ return true if cluster contains a kernel instance.
 *****************************************************************************************/
bool_t cluster_is_active( cxy_t  cxy );

/****************************************************************************************** 
 * This function selects (pseudo) randomly a valid cluster.
 * It is called by the vfs_cluster_lookup() function to place a new (missing) inode.
 * It is called by the vmm_page_allocate() function to place a distributed vseg page.
 * It is called by the dev_nic_accept() function to place a new server socket.
 ******************************************************************************************
 * @ returns the selected cluster identifier.
 *****************************************************************************************/
cxy_t cluster_random_select( void );

/******************************************************************************************
 * This function returns an extended pointer on the process descriptor in owner cluster
 * from the process <pid>. This PID can be be different from the calling process PID.
 * It can be called by any thread running in any cluster,
 ******************************************************************************************
 * @ pid  : process identifier.
 * @ return extended pointer on owner process if found / XPTR_NULL if not found.
 *****************************************************************************************/
xptr_t cluster_get_owner_process_from_pid( pid_t pid );

/******************************************************************************************
 * This function returns an extended pointer on the reference process descriptor
 * from the process <pid>. This PID can be be different from the calling process PID.
 * It can be called by any thread running in any cluster,
 ******************************************************************************************
 * @ pid  : process identifier.
 * @ return extended pointer on reference process if found / XPTR_NULL if not found.
 *****************************************************************************************/
xptr_t cluster_get_reference_process_from_pid( pid_t pid );

/******************************************************************************************
 * This function returns an extended pointer on the process descriptor copy for the
 * process identified by <pid> in cluster defined by <cxy> argument.
 * This PID can be be different from the calling process PID.
 * It can be called by any thread running in any cluster,
 ******************************************************************************************
 * @ cxy  : target cluster identifier.
 * @ pid  : process identifier.
 * @ return extended pointer on reference process if found / XPTR_NULL if not found.
 *****************************************************************************************/
xptr_t cluster_get_process_from_pid_in_cxy( cxy_t cxy,
                                            pid_t pid );

/******************************************************************************************
 * This function allocates a new PID in local cluster, that becomes the process owner.
 * It registers the process descriptor extended pointer in the local processs manager
 * pref_tbl[] array. The process descriptor itself is not modified.
 * This function is called by the process_make_fork() function, 
 * by the process_make_exec() function, and by the process_init_create() function.
 ******************************************************************************************
 * @ process    : pointer on process descriptor.
 * @ pid        : [out] allocated PID.
 * @ return 0 if success / return -1 if no PID slot available.
 *****************************************************************************************/
error_t cluster_pid_alloc( struct process_s * process,
                           pid_t            * pid );

/******************************************************************************************
 * This function removes a PID from the local process manager pref_tbl[] array.
 * It checks that removed process is owned by the local cluster and the lpid is legal.
 * No memory is released by this function.
 ******************************************************************************************
 * @ pid        : allocated PID.
 *****************************************************************************************/
void cluster_pid_release( pid_t  pid );

/******************************************************************************************
 * This function returns a pointer on the local process descriptor from the PID.
 ******************************************************************************************
 * @ pid     : searched process identifier.
 * @ returns process descriptor pointer if found / returns NULL if not found.
 *****************************************************************************************/
struct process_s * cluster_get_local_process_from_pid( pid_t pid );

/******************************************************************************************
 * This function registers a local process descriptor in the process manager local_list.
 ******************************************************************************************
 * @ process     : pointer on local process descriptor.
 *****************************************************************************************/
void cluster_process_local_link( struct process_s * process );

/******************************************************************************************
 * This function removes a local process descriptor from the process manager local_list.
 ******************************************************************************************
 * @ process     : pointer on local process descriptor.
 *****************************************************************************************/
void cluster_process_local_unlink( struct process_s * process );

/******************************************************************************************
 * This function registers a local process descriptor in the owner process manager
 * copies_list, that can be in a remote cluster.
 ******************************************************************************************
 * @ process     : pointer on local process descriptor.
 *****************************************************************************************/
void cluster_process_copies_link( struct process_s * process );

/******************************************************************************************
 * This function removes a local process descriptor from the owner process manager
 * copies_list, that can be in a remote cluster.
 ******************************************************************************************
 * @ process     : pointer on local process descriptor.
 *****************************************************************************************/
void cluster_process_copies_unlink( struct process_s * process );

/******************************************************************************************
 * This function displays on the kernel terminal TXT0 all user processes registered
 * in the cluster defined by the <cxy> argument.
 * It can be called by a thread running in any cluster.
 ******************************************************************************************
 * @ cxy   : cluster identifier.
 * @ owned : only owned process if non zero.
 *****************************************************************************************/
void cluster_processes_display( cxy_t   cxy,
                                bool_t  owned );

/******************************************************************************************
 * This function selects the core that has the lowest usage in a - possibly remote -
 * cluster identified by the <cxy> argument.
 * It can be called by a thread running in any cluster.
 ******************************************************************************************
 * @ cxy    : target cluster identifier.
 * @ return the selected core local index.
 *****************************************************************************************/
lid_t cluster_select_local_core( cxy_t  cxy );

             
#endif	/* _CLUSTER_H_ */

