/*   $Source: bitbucket.org:berkeleylab/gasnet.git/ibv-conduit/firehose_fwd.h $
 * Description: Configuration of firehose code to fit ibv-conduit
 * Copyright 2003, The Regents of the University of California
 * Terms of use are as specified in license.txt
 */

#ifndef _IBV_FIREHOSE_FWD_H
#define _IBV_FIREHOSE_FWD_H

  #if defined(__GNUC__) && !defined(inline)
    /* ANSI-ify the IB Verbs headers */
    #define inline __inline__
    #include <infiniband/verbs.h>
    #undef inline
  #else
    #include <infiniband/verbs.h>
  #endif
  #ifdef GASNETC_IBV_MAX_HCAS_CONFIGURE
    #define GASNETC_IB_MAX_HCAS GASNETC_IBV_MAX_HCAS_CONFIGURE
  #else /* no multi-rail support */
    #define GASNETC_IB_MAX_HCAS 1
  #endif

/* Set this here because we need it to match */
#define FH_BUCKET_SIZE	GASNET_PAGESIZE

/* ibv-conduit uses firehose-region */
#define FIREHOSE_REGION

/* ibv-conduit allows completion callbacks to run in handlers */
#define FIREHOSE_COMPLETION_IN_HANDLER

/* ibv-conduit has a client_t */
#define FIREHOSE_CLIENT_T
typedef struct _firehose_client_t {
    struct ibv_mr *   handle[GASNETC_IB_MAX_HCAS];	/* used to release the region */
    uint32_t          lkey[GASNETC_IB_MAX_HCAS];	/* used for local access by HCA */
    uint32_t          rkey[GASNETC_IB_MAX_HCAS];	/* used for remote access by HCA */
} firehose_client_t;

#if GASNET_SEGMENT_FAST
  /* unused, but cannot be empty */
  typedef char firehose_remotecallback_args_t;
#else // Using remote firehose
 #ifndef GASNETC_PUTINMOVE_LIMIT_MAX
  /* Compile-time max bytes to piggyback on a put/miss.
   * Environment can always specify a lesser limit, but not larger.
   *
   * Total size of firehose_remotecallback_args_t (below) must be  no larger than
   * fits in a Medium payload, along with firehose's overhead which is
   *    (1 + FH_MAX_UNPIN_REM) * sizeof(firehose_region_t)
   * Where sizeof(firehose_region_t) is
   *    2*SIZEOF_VOID_P + sizeof(firehose_client_t)
   * For a 64-bit platform and default values of FH_MAX_UNPIN_REM and GASNETC_IB_MAX_HCAS:
   *   GASNETC_PUTINMOVE_LIMIT_MAX <= GASNETC_MAX_MEDIUM - 256
   * For a 32-bit platform
   *   GASNETC_PUTINMOVE_LIMIT_MAX <= GASNETC_MAX_MEDIUM - 168
   * NOTE: these are correct at the time of writting, but subject to change.
   */
  // Unfortunately we can't *perfectly* work everything out with the preprocessor.
  // Assumes ABI has "natural alignment" of struct members and (sizeof(size_t) <= sizeof(void*))
  // Assumes FH_MAX_UNPIN_REM remains at default of 4, but that is not in scope here to verify
  #define _GASNETC_SIZEOF_FH_CLIENT_T (GASNETC_IB_MAX_HCAS*(SIZEOF_VOID_P+8))
  #define _GASNETC_SIZEOF_FH_REGION_T (2*SIZEOF_VOID_P + _GASNETC_SIZEOF_FH_CLIENT_T)
  #define _GASNETC_SIZEOF_FH_CB_ARGS_T (2*SIZEOF_VOID_P)
  #define _GASNETC_PUTINMOVE_OVERHEAD ((1+4)*_GASNETC_SIZEOF_FH_REGION_T + _GASNETC_SIZEOF_FH_CB_ARGS_T)
  #define GASNETC_PUTINMOVE_LIMIT_MAX (GASNETC_BUFSZ - _GASNETC_PUTINMOVE_OVERHEAD)
  #if (GASNETC_PUTINMOVE_LIMIT_MAX > 3072)
    /* Diminishing returns as the value is increased beyond 3k */
    #undef GASNETC_PUTINMOVE_LIMIT_MAX
    #define GASNETC_PUTINMOVE_LIMIT_MAX 3072
  #elif (GASNETC_PUTINMOVE_LIMIT_MAX < 0)
    #error Insufficient space for 'firehose moves'.  Please lower '--with-ibv-max-hcas=...' or raise '--with-ibv-max-medium=...'
    #undef GASNETC_PUTINMOVE_LIMIT_MAX
    #define GASNETC_PUTINMOVE_LIMIT_MAX 8 // prevents bad array size below from masking the #error above
  #endif
 #endif
  typedef struct {
    void	*addr;
    size_t	len;
    char	data[GASNETC_PUTINMOVE_LIMIT_MAX];
  } firehose_remotecallback_args_t;
#endif

#define FIREHOSE_REMOTE_CALLBACK_IN_HANDLER

// Check the validity of a client_t
GASNETI_INLINE(gasneti_valid_client_t)
int gasneti_valid_client_t(const firehose_client_t *client) {
  return (NULL != client->handle[0]);
}

// Permit merge of a given region if and only if the client_t is "valid"
#define FH_MAY_MERGE gasneti_valid_client_t

#endif