/*
 * Copyright 2014 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "amdgpu.h"
#include "amdgpu_drm.h"
#include "amdgpu_internal.h"
#include "util_math.h"

int amdgpu_va_range_query(amdgpu_device_handle dev,
			  enum amdgpu_gpu_va_range type, uint64_t *start, uint64_t *end)
{
	if (type == amdgpu_gpu_va_range_general) {
		*start = dev->dev_info.virtual_address_offset;
		*end = dev->dev_info.virtual_address_max;
		return 0;
	}
	return -EINVAL;
}

drm_private void amdgpu_vamgr_init(struct amdgpu_bo_va_mgr *mgr, uint64_t start,
			      uint64_t max, uint64_t alignment)
{
	mgr->va_offset = start;
	mgr->va_max = max;
	mgr->va_alignment = alignment;

	list_inithead(&mgr->va_holes);
	pthread_mutex_init(&mgr->bo_va_mutex, NULL);
}

drm_private void amdgpu_vamgr_deinit(struct amdgpu_bo_va_mgr *mgr)
{
	struct amdgpu_bo_va_hole *hole, *tmp;
	LIST_FOR_EACH_ENTRY_SAFE(hole, tmp, &mgr->va_holes, list) {
		list_del(&hole->list);
		free(hole);
	}
	pthread_mutex_destroy(&mgr->bo_va_mutex);
}

drm_private uint64_t
amdgpu_vamgr_find_va(struct amdgpu_bo_va_mgr *mgr, uint64_t size,
		     uint64_t alignment, uint64_t base_required)
{
	struct amdgpu_bo_va_hole *hole, *n;
	uint64_t offset = 0, waste = 0;

	alignment = MAX2(alignment, mgr->va_alignment);
	size = ALIGN(size, mgr->va_alignment);

	if (base_required % alignment)
		return AMDGPU_INVALID_VA_ADDRESS;

	pthread_mutex_lock(&mgr->bo_va_mutex);
	/* TODO: using more appropriate way to track the holes */
	/* first look for a hole */
	LIST_FOR_EACH_ENTRY_SAFE(hole, n, &mgr->va_holes, list) {
		if (base_required) {
			if(hole->offset > base_required ||
				(hole->offset + hole->size) < (base_required + size))
				continue;
			waste = base_required - hole->offset;
			offset = base_required;
		} else {
			offset = hole->offset;
			waste = offset % alignment;
			waste = waste ? alignment - waste : 0;
			offset += waste;
			if (offset >= (hole->offset + hole->size)) {
				continue;
			}
		}
		if (!waste && hole->size == size) {
			offset = hole->offset;
			list_del(&hole->list);
			free(hole);
			pthread_mutex_unlock(&mgr->bo_va_mutex);
			return offset;
		}
		if ((hole->size - waste) > size) {
			if (waste) {
				n = calloc(1, sizeof(struct amdgpu_bo_va_hole));
				n->size = waste;
				n->offset = hole->offset;
				list_add(&n->list, &hole->list);
			}
			hole->size -= (size + waste);
			hole->offset += size + waste;
			pthread_mutex_unlock(&mgr->bo_va_mutex);
			return offset;
		}
		if ((hole->size - waste) == size) {
			hole->size = waste;
			pthread_mutex_unlock(&mgr->bo_va_mutex);
			return offset;
		}
	}

	if (base_required) {
		if (base_required < mgr->va_offset) {
			pthread_mutex_unlock(&mgr->bo_va_mutex);
			return AMDGPU_INVALID_VA_ADDRESS;
		}
		offset = mgr->va_offset;
		waste = base_required - mgr->va_offset;
	} else {
		offset = mgr->va_offset;
		waste = offset % alignment;
		waste = waste ? alignment - waste : 0;
	}

	if (offset + waste + size > mgr->va_max) {
		pthread_mutex_unlock(&mgr->bo_va_mutex);
		return AMDGPU_INVALID_VA_ADDRESS;
	}

	if (waste) {
		n = calloc(1, sizeof(struct amdgpu_bo_va_hole));
		n->size = waste;
		n->offset = offset;
		list_add(&n->list, &mgr->va_holes);
	}

	offset += waste;
	mgr->va_offset += size + waste;
	pthread_mutex_unlock(&mgr->bo_va_mutex);
	return offset;
}

drm_private void
amdgpu_vamgr_free_va(struct amdgpu_bo_va_mgr *mgr, uint64_t va, uint64_t size)
{
	struct amdgpu_bo_va_hole *hole;

	if (va == AMDGPU_INVALID_VA_ADDRESS)
		return;

	size = ALIGN(size, mgr->va_alignment);

	pthread_mutex_lock(&mgr->bo_va_mutex);
	if ((va + size) == mgr->va_offset) {
		mgr->va_offset = va;
		/* Delete uppermost hole if it reaches the new top */
		if (!LIST_IS_EMPTY(&mgr->va_holes)) {
			hole = container_of(mgr->va_holes.next, hole, list);
			if ((hole->offset + hole->size) == va) {
				mgr->va_offset = hole->offset;
				list_del(&hole->list);
				free(hole);
			}
		}
	} else {
		struct amdgpu_bo_va_hole *next;

		hole = container_of(&mgr->va_holes, hole, list);
		LIST_FOR_EACH_ENTRY(next, &mgr->va_holes, list) {
			if (next->offset < va)
				break;
			hole = next;
		}

		if (&hole->list != &mgr->va_holes) {
			/* Grow upper hole if it's adjacent */
			if (hole->offset == (va + size)) {
				hole->offset = va;
				hole->size += size;
				/* Merge lower hole if it's adjacent */
				if (next != hole
						&& &next->list != &mgr->va_holes
						&& (next->offset + next->size) == va) {
					next->size += hole->size;
					list_del(&hole->list);
					free(hole);
				}
				goto out;
			}
		}

		/* Grow lower hole if it's adjacent */
		if (next != hole && &next->list != &mgr->va_holes &&
				(next->offset + next->size) == va) {
			next->size += size;
			goto out;
		}

		/* FIXME on allocation failure we just lose virtual address space
		 * maybe print a warning
		 */
		next = calloc(1, sizeof(struct amdgpu_bo_va_hole));
		if (next) {
			next->size = size;
			next->offset = va;
			list_add(&next->list, &hole->list);
		}
	}
out:
	pthread_mutex_unlock(&mgr->bo_va_mutex);
}

int amdgpu_va_range_alloc(amdgpu_device_handle dev,
			  enum amdgpu_gpu_va_range va_range_type,
			  uint64_t size,
			  uint64_t va_base_alignment,
			  uint64_t va_base_required,
			  uint64_t *va_base_allocated,
			  amdgpu_va_handle *va_range_handle,
			  uint64_t flags)
{
	struct amdgpu_bo_va_mgr *vamgr;

	if (flags & AMDGPU_VA_RANGE_32_BIT)
		vamgr = dev->vamgr_32;
	else
		vamgr = dev->vamgr;

	va_base_alignment = MAX2(va_base_alignment, vamgr->va_alignment);
	size = ALIGN(size, vamgr->va_alignment);

	*va_base_allocated = amdgpu_vamgr_find_va(vamgr, size,
					va_base_alignment, va_base_required);

	if (!(flags & AMDGPU_VA_RANGE_32_BIT) &&
	    (*va_base_allocated == AMDGPU_INVALID_VA_ADDRESS)) {
		/* fallback to 32bit address */
		vamgr = dev->vamgr_32;
		*va_base_allocated = amdgpu_vamgr_find_va(vamgr, size,
					va_base_alignment, va_base_required);
	}

	if (*va_base_allocated != AMDGPU_INVALID_VA_ADDRESS) {
		struct amdgpu_va* va;
		va = calloc(1, sizeof(struct amdgpu_va));
		if(!va){
			amdgpu_vamgr_free_va(vamgr, *va_base_allocated, size);
			return -ENOMEM;
		}
		va->dev = dev;
		va->address = *va_base_allocated;
		va->size = size;
		va->range = va_range_type;
		va->vamgr = vamgr;
		*va_range_handle = va;
	} else {
		return -EINVAL;
	}

	return 0;
}

int amdgpu_va_range_free(amdgpu_va_handle va_range_handle)
{
	if(!va_range_handle || !va_range_handle->address)
		return 0;

	amdgpu_vamgr_free_va(va_range_handle->vamgr,
			va_range_handle->address,
			va_range_handle->size);
	free(va_range_handle);
	return 0;
}