/*
 * cluster.h - Cluster-Manager definition
 *
 * authors  Ghassan Almaless (2008,2009,2010,2011,2012)
 *          Mohamed Lamine Karaoui (2015)
 *          Alain Greiner (2016,2017)
 *
 * 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_types.h>
#include <bits.h>
#include <spinlock.h>
#include <readlock.h>
#include <remote_barrier.h>
#include <list.h>
#include <xlist.h>
#include <dqdt.h>
#include <kmem.h>
#include <hal_atomic.h>
#include <ppm.h>
#include <kcm.h>
#include <khm.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 structures:
 * 1) The 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 process descriptors in cluster K.
 *    A process descriptor P is present in K, as soon as P has a thread in cluster K.
 *
 * 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.
 ******************************************************************************************/

typedef struct process_manager_s
{
	xptr_t            pref_tbl[CONFIG_MAX_PROCESS_PER_CLUSTER];  /*! reference  process   */
	spinlock_t        pref_lock;              /*! lock protecting lpid allocation/release */
    uint32_t          pref_nr;                /*! number of processes owned by cluster    */

    xlist_entry_t     local_root;             /*! root of list of process in cluster      */
    remote_spinlock_t local_lock;             /*! lock protecting access to 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_spinlock_t copies_lock[CONFIG_MAX_PROCESS_PER_CLUSTER];  /*! one lock per list */
    uint32_t          copies_nr[CONFIG_MAX_PROCESS_PER_CLUSTER];    /*! number of copies  */
}
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
{
	spinlock_t        kcm_lock;        /*! local, protect creation of KCM allocators      */

    // 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)      */
	cxy_t             io_cxy;          /*! io cluster identifier                          */
    uint32_t          dqdt_root_level; /*! index of root node in dqdt_tbl[]               */

    // 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             */

    // memory allocators
	ppm_t             ppm;             /*! embedded kernel page manager                   */
	khm_t             khm;             /*! embedded kernel heap manager                   */
	kcm_t             kcm;             /*! embedded kernel cache manager (for KCMs)       */
    kcm_t           * kcm_tbl[KMEM_TYPES_NR];         /*! pointers on allocated KCMs      */

    // RPC
	remote_fifo_t     rpc_fifo;        /*! RPC fifo (one per cluster)                     */
    uint32_t          rpc_threads;     /*! current number of RPC threads in cluster       */

    // DQDT
    int32_t           pages_var;       /*! pages number increment from last DQQT update   */
    int32_t           threads_var;     /*! threads number increment from last DQDT update */

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

    // 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)

/******************************************************************************************
 * This generic function initialises the local cluster manager from information found
 * in the local boot-info structure. It initializes the following local resources:
 * - the global platform parameters,
 * - the specific cluster parameters,
 * - the lock protecting KCM creation,
 * - the local DQDT nodes,
 * - the PPM, KHM, and KCM allocators,
 * - the local core descriptors,
 * - the local RPC FIFO,
 * - the process manager.
 * It does NOT initialise the local device descriptors.
 ******************************************************************************************
 * @ info : pointer on the local boot_info_t structure build by the bootloader.
 *****************************************************************************************/
error_t cluster_init( boot_info_t * info );

/******************************************************************************************
 * This function checks the validity of a cluster identifier. 
 ******************************************************************************************
 * @ cxy    : cluster identifier to be checked.
 * @ returns true if the identified cluster does not exist.
 *****************************************************************************************/
bool_t cluster_is_undefined( cxy_t cxy );


/*****************************************************************************************/
/***************   Process Management Operations   ***************************************/
/*****************************************************************************************/

/******************************************************************************************
 * 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 success / return XPTR_NULL if error.
 *****************************************************************************************/
xptr_t cluster_get_reference_process_from_pid( 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. 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.
 * It uses the RPC
 * to create a local process descriptor copy if it does not exist yet.
 ******************************************************************************************
 * @ 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 );



/*****************************************************************************************/
/***************   Cores Management Operations   *****************************************/
/*****************************************************************************************/

/******************************************************************************************
 * This function increments the "cores_in_kernel" variable in cluster descriptor.
 *****************************************************************************************/
void cluster_core_kernel_enter();

/******************************************************************************************
 * This function decrements the "cores_in_kernel" variable in cluster descriptor.
 *****************************************************************************************/
void cluster_core_kernel_exit();

/******************************************************************************************
 * This function returns the core local index that has the lowest usage in local cluster.
 *****************************************************************************************/
lid_t cluster_select_local_core();

#endif	/* _CLUSTER_H_ */
