// Copyright 2023 The IREE Authors
//
// Licensed under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

#include "experimental/cuda2/cuda_device.h"

#include <iree/hal/device.h>
#include <stddef.h>
#include <stdint.h>
#include <string.h>

#include "experimental/cuda2/cuda_allocator.h"
#include "experimental/cuda2/cuda_buffer.h"
#include "experimental/cuda2/cuda_dynamic_symbols.h"
#include "experimental/cuda2/cuda_status_util.h"
#include "experimental/cuda2/memory_pools.h"
#include "experimental/cuda2/pipeline_layout.h"
#include "iree/base/internal/arena.h"
#include "iree/base/internal/math.h"
#include "iree/hal/utils/buffer_transfer.h"
#include "iree/hal/utils/deferred_command_buffer.h"

//===----------------------------------------------------------------------===//
// iree_hal_cuda2_device_t
//===----------------------------------------------------------------------===//

typedef struct iree_hal_cuda2_device_t {
  // Abstract resource used for injecting reference counting and vtable;
  // must be at offset 0.
  iree_hal_resource_t resource;
  iree_string_view_t identifier;

  // Block pool used for command buffers with a larger block size (as command
  // buffers can contain inlined data uploads).
  iree_arena_block_pool_t block_pool;

  // Optional driver that owns the CUDA symbols. We retain it for our lifetime
  // to ensure the symbols remains valid.
  iree_hal_driver_t* driver;

  const iree_hal_cuda2_dynamic_symbols_t* cuda_symbols;

  // Parameters used to control device behavior.
  iree_hal_cuda2_device_params_t params;

  CUcontext cu_context;
  CUdevice cu_device;
  // TODO: support multiple streams.
  CUstream cu_stream;

  iree_allocator_t host_allocator;

  // Device memory pools and allocators.
  bool supports_memory_pools;
  iree_hal_cuda2_memory_pools_t memory_pools;
  iree_hal_allocator_t* device_allocator;
} iree_hal_cuda2_device_t;

static const iree_hal_device_vtable_t iree_hal_cuda2_device_vtable;

static iree_hal_cuda2_device_t* iree_hal_cuda2_device_cast(
    iree_hal_device_t* base_value) {
  IREE_HAL_ASSERT_TYPE(base_value, &iree_hal_cuda2_device_vtable);
  return (iree_hal_cuda2_device_t*)base_value;
}

static iree_hal_cuda2_device_t* iree_hal_cuda2_device_cast_unsafe(
    iree_hal_device_t* base_value) {
  return (iree_hal_cuda2_device_t*)base_value;
}

IREE_API_EXPORT void iree_hal_cuda2_device_params_initialize(
    iree_hal_cuda2_device_params_t* out_params) {
  memset(out_params, 0, sizeof(*out_params));
  out_params->arena_block_size = 32 * 1024;
  out_params->queue_count = 1;
  out_params->async_allocations = true;
}

static iree_status_t iree_hal_cuda2_device_check_params(
    const iree_hal_cuda2_device_params_t* params) {
  if (params->arena_block_size < 4096) {
    return iree_make_status(IREE_STATUS_INVALID_ARGUMENT,
                            "arena block size too small (< 4096 bytes)");
  }
  if (params->queue_count == 0) {
    return iree_make_status(IREE_STATUS_INVALID_ARGUMENT,
                            "at least one queue is required");
  }
  return iree_ok_status();
}

static iree_status_t iree_hal_cuda2_device_create_internal(
    iree_hal_driver_t* driver, iree_string_view_t identifier,
    const iree_hal_cuda2_device_params_t* params, CUdevice cu_device,
    CUstream stream, CUcontext context,
    const iree_hal_cuda2_dynamic_symbols_t* symbols,
    iree_allocator_t host_allocator, iree_hal_device_t** out_device) {
  iree_hal_cuda2_device_t* device = NULL;
  iree_host_size_t total_size = iree_sizeof_struct(*device) + identifier.size;
  IREE_RETURN_IF_ERROR(
      iree_allocator_malloc(host_allocator, total_size, (void**)&device));
  memset(device, 0, total_size);

  iree_hal_resource_initialize(&iree_hal_cuda2_device_vtable,
                               &device->resource);
  iree_string_view_append_to_buffer(
      identifier, &device->identifier,
      (char*)device + iree_sizeof_struct(*device));
  iree_arena_block_pool_initialize(params->arena_block_size, host_allocator,
                                   &device->block_pool);
  device->driver = driver;
  iree_hal_driver_retain(device->driver);
  device->cuda_symbols = symbols;
  device->params = *params;
  device->cu_context = context;
  device->cu_device = cu_device;
  device->cu_stream = stream;
  device->host_allocator = host_allocator;

  iree_status_t status = iree_ok_status();

  // Memory pool support is conditional.
  if (iree_status_is_ok(status) && params->async_allocations) {
    int supports_memory_pools = 0;
    status = IREE_CURESULT_TO_STATUS(
        symbols,
        cuDeviceGetAttribute(&supports_memory_pools,
                             CU_DEVICE_ATTRIBUTE_MEMORY_POOLS_SUPPORTED,
                             cu_device),
        "cuDeviceGetAttribute");
    device->supports_memory_pools = supports_memory_pools != 0;
  }

  // Create memory pools first so that we can share them with the allocator.
  if (iree_status_is_ok(status) && device->supports_memory_pools) {
    status = iree_hal_cuda2_memory_pools_initialize(
        symbols, cu_device, &params->memory_pools, host_allocator,
        &device->memory_pools);
  }

  if (iree_status_is_ok(status)) {
    status = iree_hal_cuda2_allocator_create(
        (iree_hal_device_t*)device, symbols, cu_device, stream,
        device->supports_memory_pools ? &device->memory_pools : NULL,
        host_allocator, &device->device_allocator);
  }

  if (iree_status_is_ok(status)) {
    *out_device = (iree_hal_device_t*)device;
  } else {
    iree_hal_device_release((iree_hal_device_t*)device);
  }
  return status;
}

iree_status_t iree_hal_cuda2_device_create(
    iree_hal_driver_t* driver, iree_string_view_t identifier,
    const iree_hal_cuda2_device_params_t* params,
    const iree_hal_cuda2_dynamic_symbols_t* symbols, CUdevice device,
    iree_allocator_t host_allocator, iree_hal_device_t** out_device) {
  IREE_ASSERT_ARGUMENT(driver);
  IREE_ASSERT_ARGUMENT(params);
  IREE_ASSERT_ARGUMENT(symbols);
  IREE_ASSERT_ARGUMENT(out_device);
  IREE_TRACE_ZONE_BEGIN(z0);

  iree_status_t status = iree_hal_cuda2_device_check_params(params);

  // Get the main context for the device.
  CUcontext context = NULL;
  if (iree_status_is_ok(status)) {
    status = IREE_CURESULT_TO_STATUS(
        symbols, cuDevicePrimaryCtxRetain(&context, device));
  }
  if (iree_status_is_ok(status)) {
    status = IREE_CURESULT_TO_STATUS(symbols, cuCtxSetCurrent(context));
  }

  // Create the default stream for the device.
  CUstream stream = NULL;
  if (iree_status_is_ok(status)) {
    status = IREE_CURESULT_TO_STATUS(
        symbols, cuStreamCreate(&stream, CU_STREAM_NON_BLOCKING));
  }

  if (iree_status_is_ok(status)) {
    status = iree_hal_cuda2_device_create_internal(
        driver, identifier, params, device, stream, context, symbols,
        host_allocator, out_device);
  }
  if (!iree_status_is_ok(status)) {
    if (stream) symbols->cuStreamDestroy(stream);
    if (context) symbols->cuDevicePrimaryCtxRelease(device);
  }

  IREE_TRACE_ZONE_END(z0);
  return status;
}

CUcontext iree_hal_cuda2_device_context(iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device =
      iree_hal_cuda2_device_cast_unsafe(base_device);
  return device->cu_context;
}

const iree_hal_cuda2_dynamic_symbols_t* iree_hal_cuda2_device_dynamic_symbols(
    iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device =
      iree_hal_cuda2_device_cast_unsafe(base_device);
  return device->cuda_symbols;
}

static void iree_hal_cuda2_device_destroy(iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  iree_allocator_t host_allocator = iree_hal_device_host_allocator(base_device);
  IREE_TRACE_ZONE_BEGIN(z0);

  // There should be no more buffers live that use the allocator.
  iree_hal_allocator_release(device->device_allocator);

  // Destroy memory pools that hold on to reserved memory.
  iree_hal_cuda2_memory_pools_deinitialize(&device->memory_pools);

  // TODO: support multiple streams.
  IREE_CUDA_IGNORE_ERROR(device->cuda_symbols,
                         cuStreamDestroy(device->cu_stream));

  IREE_CUDA_IGNORE_ERROR(device->cuda_symbols,
                         cuDevicePrimaryCtxRelease(device->cu_device));

  iree_arena_block_pool_deinitialize(&device->block_pool);

  // Finally, destroy the device.
  iree_hal_driver_release(device->driver);

  iree_allocator_free(host_allocator, device);

  IREE_TRACE_ZONE_END(z0);
}

static iree_string_view_t iree_hal_cuda2_device_id(
    iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  return device->identifier;
}

static iree_allocator_t iree_hal_cuda2_device_host_allocator(
    iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  return device->host_allocator;
}

static iree_hal_allocator_t* iree_hal_cuda2_device_allocator(
    iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  return device->device_allocator;
}

static void iree_hal_cuda2_replace_device_allocator(
    iree_hal_device_t* base_device, iree_hal_allocator_t* new_allocator) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  iree_hal_allocator_retain(new_allocator);
  iree_hal_allocator_release(device->device_allocator);
  device->device_allocator = new_allocator;
}

static void iree_hal_cuda2_replace_channel_provider(
    iree_hal_device_t* base_device, iree_hal_channel_provider_t* new_provider) {
  // TODO: implement this together with channel support.
}

static iree_status_t iree_hal_cuda2_device_trim(
    iree_hal_device_t* base_device) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  iree_arena_block_pool_trim(&device->block_pool);
  IREE_RETURN_IF_ERROR(iree_hal_allocator_trim(device->device_allocator));
  if (device->supports_memory_pools) {
    IREE_RETURN_IF_ERROR(iree_hal_cuda2_memory_pools_trim(
        &device->memory_pools, &device->params.memory_pools));
  }
  return iree_ok_status();
}

static iree_status_t iree_hal_cuda2_device_query_attribute(
    iree_hal_cuda2_device_t* device, CUdevice_attribute attribute,
    int64_t* out_value) {
  int value = 0;
  IREE_CUDA_RETURN_IF_ERROR(
      device->cuda_symbols,
      cuDeviceGetAttribute(&value, attribute, device->cu_device),
      "cuDeviceGetAttribute");
  *out_value = value;
  return iree_ok_status();
}

static iree_status_t iree_hal_cuda2_device_query_i64(
    iree_hal_device_t* base_device, iree_string_view_t category,
    iree_string_view_t key, int64_t* out_value) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  *out_value = 0;

  if (iree_string_view_equal(category, IREE_SV("hal.executable.format"))) {
    *out_value = iree_string_view_equal(key, IREE_SV("cuda-nvptx-fb")) ? 1 : 0;
    return iree_ok_status();
  }

  if (iree_string_view_equal(category, IREE_SV("cuda.device"))) {
    if (iree_string_view_equal(key, IREE_SV("compute_capability_major"))) {
      return iree_hal_cuda2_device_query_attribute(
          device, CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MAJOR, out_value);
    } else if (iree_string_view_equal(key,
                                      IREE_SV("compute_capability_minor"))) {
      return iree_hal_cuda2_device_query_attribute(
          device, CU_DEVICE_ATTRIBUTE_COMPUTE_CAPABILITY_MINOR, out_value);
    }
  }

  return iree_make_status(
      IREE_STATUS_NOT_FOUND,
      "unknown device configuration key value '%.*s :: %.*s'",
      (int)category.size, category.data, (int)key.size, key.data);
}

static iree_status_t iree_hal_cuda2_device_create_channel(
    iree_hal_device_t* base_device, iree_hal_queue_affinity_t queue_affinity,
    iree_hal_channel_params_t params, iree_hal_channel_t** out_channel) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "channel not yet implmeneted");
}

static iree_status_t iree_hal_cuda2_device_create_command_buffer(
    iree_hal_device_t* base_device, iree_hal_command_buffer_mode_t mode,
    iree_hal_command_category_t command_categories,
    iree_hal_queue_affinity_t queue_affinity, iree_host_size_t binding_capacity,
    iree_hal_command_buffer_t** out_command_buffer) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "command buffer not yet implmeneted");
}

static iree_status_t iree_hal_cuda2_device_create_descriptor_set_layout(
    iree_hal_device_t* base_device,
    iree_hal_descriptor_set_layout_flags_t flags,
    iree_host_size_t binding_count,
    const iree_hal_descriptor_set_layout_binding_t* bindings,
    iree_hal_descriptor_set_layout_t** out_descriptor_set_layout) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  return iree_hal_cuda2_descriptor_set_layout_create(
      flags, binding_count, bindings, device->host_allocator,
      out_descriptor_set_layout);
}

static iree_status_t iree_hal_cuda2_device_create_event(
    iree_hal_device_t* base_device, iree_hal_event_t** out_event) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "event not yet implmeneted");
}

static iree_status_t iree_hal_cuda2_device_create_executable_cache(
    iree_hal_device_t* base_device, iree_string_view_t identifier,
    iree_loop_t loop, iree_hal_executable_cache_t** out_executable_cache) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "executable cache not yet implmeneted");
}

static iree_status_t iree_hal_cuda2_device_create_pipeline_layout(
    iree_hal_device_t* base_device, iree_host_size_t push_constants,
    iree_host_size_t set_layout_count,
    iree_hal_descriptor_set_layout_t* const* set_layouts,
    iree_hal_pipeline_layout_t** out_pipeline_layout) {
  iree_hal_cuda2_device_t* device = iree_hal_cuda2_device_cast(base_device);
  return iree_hal_cuda2_pipeline_layout_create(
      set_layout_count, set_layouts, push_constants, device->host_allocator,
      out_pipeline_layout);
}

static iree_status_t iree_hal_cuda2_device_create_semaphore(
    iree_hal_device_t* base_device, uint64_t initial_value,
    iree_hal_semaphore_t** out_semaphore) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "semaphore not yet implmeneted");
}

static iree_hal_semaphore_compatibility_t
iree_hal_cuda2_device_query_semaphore_compatibility(
    iree_hal_device_t* base_device, iree_hal_semaphore_t* semaphore) {
  // TODO: implement CUDA semaphores.
  return IREE_HAL_SEMAPHORE_COMPATIBILITY_NONE;
}

// TODO: implement multiple streams; today we only have one and queue_affinity
//       is ignored.
// TODO: implement proper semaphores in CUDA to ensure ordering and avoid
//       the barrier here.
static iree_status_t iree_hal_cuda2_device_queue_alloca(
    iree_hal_device_t* base_device, iree_hal_queue_affinity_t queue_affinity,
    const iree_hal_semaphore_list_t wait_semaphore_list,
    const iree_hal_semaphore_list_t signal_semaphore_list,
    iree_hal_allocator_pool_t pool, iree_hal_buffer_params_t params,
    iree_device_size_t allocation_size,
    iree_hal_buffer_t** IREE_RESTRICT out_buffer) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "queue alloca not yet implmeneted");
}

// TODO: implement multiple streams; today we only have one and queue_affinity
//       is ignored.
// TODO: implement proper semaphores in CUDA to ensure ordering and avoid
//       the barrier here.
static iree_status_t iree_hal_cuda2_device_queue_dealloca(
    iree_hal_device_t* base_device, iree_hal_queue_affinity_t queue_affinity,
    const iree_hal_semaphore_list_t wait_semaphore_list,
    const iree_hal_semaphore_list_t signal_semaphore_list,
    iree_hal_buffer_t* buffer) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "queue dealloca not yet implmeneted");
}

static iree_status_t iree_hal_cuda2_device_queue_execute(
    iree_hal_device_t* base_device, iree_hal_queue_affinity_t queue_affinity,
    const iree_hal_semaphore_list_t wait_semaphore_list,
    const iree_hal_semaphore_list_t signal_semaphore_list,
    iree_host_size_t command_buffer_count,
    iree_hal_command_buffer_t* const* command_buffers) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "queue execution not yet implmeneted");
}

static iree_status_t iree_hal_cuda2_device_queue_flush(
    iree_hal_device_t* base_device, iree_hal_queue_affinity_t queue_affinity) {
  // Currently unused; we flush as submissions are made.
  return iree_ok_status();
}

static iree_status_t iree_hal_cuda2_device_wait_semaphores(
    iree_hal_device_t* base_device, iree_hal_wait_mode_t wait_mode,
    const iree_hal_semaphore_list_t semaphore_list, iree_timeout_t timeout) {
  return iree_make_status(IREE_STATUS_UNIMPLEMENTED,
                          "semaphore not yet implemented");
}

static iree_status_t iree_hal_cuda2_device_profiling_begin(
    iree_hal_device_t* base_device,
    const iree_hal_device_profiling_options_t* options) {
  // Unimplemented (and that's ok).
  // We could hook in to CUPTI here or use the much simpler cuProfilerStart API.
  return iree_ok_status();
}

static iree_status_t iree_hal_cuda2_device_profiling_end(
    iree_hal_device_t* base_device) {
  // Unimplemented (and that's ok).
  return iree_ok_status();
}

static const iree_hal_device_vtable_t iree_hal_cuda2_device_vtable = {
    .destroy = iree_hal_cuda2_device_destroy,
    .id = iree_hal_cuda2_device_id,
    .host_allocator = iree_hal_cuda2_device_host_allocator,
    .device_allocator = iree_hal_cuda2_device_allocator,
    .replace_device_allocator = iree_hal_cuda2_replace_device_allocator,
    .replace_channel_provider = iree_hal_cuda2_replace_channel_provider,
    .trim = iree_hal_cuda2_device_trim,
    .query_i64 = iree_hal_cuda2_device_query_i64,
    .create_channel = iree_hal_cuda2_device_create_channel,
    .create_command_buffer = iree_hal_cuda2_device_create_command_buffer,
    .create_descriptor_set_layout =
        iree_hal_cuda2_device_create_descriptor_set_layout,
    .create_event = iree_hal_cuda2_device_create_event,
    .create_executable_cache = iree_hal_cuda2_device_create_executable_cache,
    .create_pipeline_layout = iree_hal_cuda2_device_create_pipeline_layout,
    .create_semaphore = iree_hal_cuda2_device_create_semaphore,
    .query_semaphore_compatibility =
        iree_hal_cuda2_device_query_semaphore_compatibility,
    .transfer_range = iree_hal_device_submit_transfer_range_and_wait,
    .queue_alloca = iree_hal_cuda2_device_queue_alloca,
    .queue_dealloca = iree_hal_cuda2_device_queue_dealloca,
    .queue_execute = iree_hal_cuda2_device_queue_execute,
    .queue_flush = iree_hal_cuda2_device_queue_flush,
    .wait_semaphores = iree_hal_cuda2_device_wait_semaphores,
    .profiling_begin = iree_hal_cuda2_device_profiling_begin,
    .profiling_end = iree_hal_cuda2_device_profiling_end,
};