/*
 *   hostrpc_externs.c: Definition of hostrpc externals
 *

MIT License

Copyright © 2020 Advanced Micro Devices, Inc.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is furnished
to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

*/

#include "hostrpc_internal.h"
#include "hsa_ext_amd.h"
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>

// FIXME, move some of this to hostrpc_internal.h
typedef struct atl_hcq_element_s atl_hcq_element_t;
struct atl_hcq_element_s {
  buffer_t *hcb;
  hsa_queue_t *hsa_q;
  atl_hcq_element_t *next_ptr;
};

//  Persistent static values for the hcq linked list
static atl_hcq_element_t *atl_hcq_front = NULL;
static atl_hcq_element_t *atl_hcq_rear = NULL;
static int atl_hcq_count = 0;
static amd_hostcall_consumer_t *atl_hcq_consumer = NULL;

static int atl_hcq_size() { return atl_hcq_count; }

static atl_hcq_element_t *atl_hcq_push(buffer_t *hcb, hsa_queue_t *hsa_q,
                                       uint32_t devid) {
  // FIXME , check rc of these mallocs
  if (atl_hcq_rear == NULL) {
    atl_hcq_rear = (atl_hcq_element_t *)malloc(sizeof(atl_hcq_element_t));
    atl_hcq_front = atl_hcq_rear;
  } else {
    atl_hcq_element_t *new_rear =
        (atl_hcq_element_t *)malloc(sizeof(atl_hcq_element_t));
    atl_hcq_rear->next_ptr = new_rear;
    atl_hcq_rear = new_rear;
  }
  atl_hcq_rear->hcb = hcb;
  atl_hcq_rear->hsa_q = hsa_q;
  atl_hcq_rear->next_ptr = NULL;
  atl_hcq_count++;
  return atl_hcq_rear;
}

static atl_hcq_element_t *atl_hcq_find_by_hsa_q(hsa_queue_t *hsa_q) {
  atl_hcq_element_t *this_front = atl_hcq_front;
  int reverse_counter = atl_hcq_size();
  while (reverse_counter) {
    if (this_front->hsa_q == hsa_q)
      return this_front;
    this_front = this_front->next_ptr;
    reverse_counter--;
  }
  return NULL;
}

static buffer_t *atl_hcq_create_buffer(unsigned int num_packets) {
  if (num_packets == 0) {
    printf("num_packets cannot be zero \n");
    abort();
  }
  size_t size = amd_hostcall_get_buffer_size(num_packets);
  uint32_t align = amd_hostcall_get_buffer_alignment();
  void *newbuffer = NULL;
  hsa_status_t err = host_malloc(&newbuffer, size + align);
  if (!newbuffer || (err != HSA_STATUS_SUCCESS)) {
    printf("call to impl_malloc failed \n");
    abort();
  }
  if (amd_hostcall_initialize_buffer(newbuffer, num_packets) !=
      AMD_HOSTCALL_SUCCESS) {
    printf("call to  amd_hostcall_initialize_buffer failed \n");
    abort();
  }
  // printf("created hostcall buffer %p with %d packets \n", newbuffer,
  // num_packets);
  return (buffer_t *)newbuffer;
}

// The following  three external functions are called by plugin.
//
unsigned long hostrpc_assign_buffer(hsa_agent_t agent, hsa_queue_t *this_Q,
                                    uint32_t device_id) {
  atl_hcq_element_t *llq_elem;
  llq_elem = atl_hcq_find_by_hsa_q(this_Q);
  if (!llq_elem) {
    // May be the first call. Create consumer if so
    if (!atl_hcq_consumer) {
      atl_hcq_consumer = amd_hostcall_create_consumer();
      // Spawns a thread
      amd_hostcall_launch_consumer(atl_hcq_consumer);
    }

    // FIXME: error check for this function
    uint32_t numCu;
    // hsa_status_t err =
    hsa_agent_get_info(
        agent, (hsa_agent_info_t)HSA_AMD_AGENT_INFO_COMPUTE_UNIT_COUNT, &numCu);
    // ErrorCheck(Could not get number of cus, err);
    uint32_t waverPerCu;
    // err =
    hsa_agent_get_info(agent,
                       (hsa_agent_info_t)HSA_AMD_AGENT_INFO_MAX_WAVES_PER_CU,
                       &waverPerCu);
    // ErrorCheck(Could not get number of waves per cu, err);
    unsigned int minpackets = numCu * waverPerCu;
    //  For now, we create one bufer and one consumer per IMPL hsa queue
    buffer_t *hcb = atl_hcq_create_buffer(minpackets);
    hcb->device_id = device_id;
    amd_hostcall_register_buffer(atl_hcq_consumer, hcb);
    // create element of linked list hcq.
    llq_elem = atl_hcq_push(hcb, this_Q, device_id);
  }
  return (unsigned long)llq_elem->hcb;
}

hsa_status_t hostrpc_init() { return HSA_STATUS_SUCCESS; }

hsa_status_t hostrpc_terminate() {
  atl_hcq_element_t *this_front = atl_hcq_front;
  atl_hcq_element_t *last_front;
  int reverse_counter = atl_hcq_size();
  if (atl_hcq_consumer) {
    amd_hostcall_destroy_consumer(atl_hcq_consumer);
    atl_hcq_consumer = NULL;
  }
  while (reverse_counter) {
    impl_free(this_front->hcb);
    last_front = this_front;
    this_front = this_front->next_ptr;
    free(last_front);
    reverse_counter--;
  }
  atl_hcq_count = 0;
  atl_hcq_front = atl_hcq_rear = NULL;
  return HSA_STATUS_SUCCESS;
}