/*
 * Copyright (C) 2019 Intel Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <e820.h>
#include <mmu.h>
#include <vm.h>
#include <reloc.h>
#include <vacpi.h>
#include <logmsg.h>

#define ENTRY_HPA1		2U
#define ENTRY_HPA1_HI		6U

static struct e820_entry sos_vm_e820[E820_MAX_ENTRIES];
static struct e820_entry pre_vm_e820[PRE_VM_NUM][E820_MAX_ENTRIES];

static void filter_mem_from_sos_e820(struct acrn_vm *vm, uint64_t start_pa, uint64_t end_pa)
{
	uint32_t i;
	uint64_t entry_start;
	uint64_t entry_end;
	uint32_t entries_count = vm->e820_entry_num;
	struct e820_entry *entry, new_entry = {0};

	for (i = 0U; i < entries_count; i++) {
		entry = &sos_vm_e820[i];
		entry_start = entry->baseaddr;
		entry_end = entry->baseaddr + entry->length;

		/* No need handle in these cases*/
		if ((entry->type != E820_TYPE_RAM) || (entry_end <= start_pa) || (entry_start >= end_pa)) {
			continue;
		}

		/* filter out the specific memory and adjust length of this entry*/
		if ((entry_start < start_pa) && (entry_end <= end_pa)) {
			entry->length = start_pa - entry_start;
			continue;
		}

		/* filter out the specific memory and need to create a new entry*/
		if ((entry_start < start_pa) && (entry_end > end_pa)) {
			entry->length = start_pa - entry_start;
			new_entry.baseaddr = end_pa;
			new_entry.length = entry_end - end_pa;
			new_entry.type = E820_TYPE_RAM;
			continue;
		}

		/* This entry is within the range of specific memory
		 * change to E820_TYPE_RESERVED
		 */
		if ((entry_start >= start_pa) && (entry_end <= end_pa)) {
			entry->type = E820_TYPE_RESERVED;
			continue;
		}

		if ((entry_start >= start_pa) && (entry_start < end_pa) && (entry_end > end_pa)) {
			entry->baseaddr = end_pa;
			entry->length = entry_end - end_pa;
			continue;
		}
	}

	if (new_entry.length > 0UL) {
		entries_count++;
		ASSERT(entries_count <= E820_MAX_ENTRIES, "e820 entry overflow");
		entry = &sos_vm_e820[entries_count - 1U];
		entry->baseaddr = new_entry.baseaddr;
		entry->length = new_entry.length;
		entry->type = new_entry.type;
		vm->e820_entry_num = entries_count;
	}

}

/**
 * before boot sos_vm(service OS), call it to hide HV and prelaunched VM memory in e820 table from sos_vm
 *
 * @pre vm != NULL
 */
void create_sos_vm_e820(struct acrn_vm *vm)
{
	uint16_t vm_id;
	uint64_t hv_start_pa = hva2hpa((void *)(get_hv_image_base()));
	uint64_t hv_end_pa  = hv_start_pa + CONFIG_HV_RAM_SIZE;
	uint32_t entries_count = get_e820_entries_count();
	const struct mem_range *p_mem_range_info = get_mem_range_info();
	struct acrn_vm_config *sos_vm_config = get_vm_config(vm->vm_id);

	(void)memcpy_s((void *)sos_vm_e820, entries_count * sizeof(struct e820_entry),
			(const void *)get_e820_entry(), entries_count * sizeof(struct e820_entry));

	vm->e820_entry_num = entries_count;
	vm->e820_entries = sos_vm_e820;
	/* filter out hv memory from e820 table */
	filter_mem_from_sos_e820(vm, hv_start_pa, hv_end_pa);
	sos_vm_config->memory.size = p_mem_range_info->total_mem_size - CONFIG_HV_RAM_SIZE;

	/* filter out prelaunched vm memory from e820 table */
	for (vm_id = 0U; vm_id < CONFIG_MAX_VM_NUM; vm_id++) {
		struct acrn_vm_config *vm_config = get_vm_config(vm_id);

		if (vm_config->load_order == PRE_LAUNCHED_VM) {
			filter_mem_from_sos_e820(vm, vm_config->memory.start_hpa,
					vm_config->memory.start_hpa + vm_config->memory.size);
			sos_vm_config->memory.size -= vm_config->memory.size;

			/* if HPA2 is available, filter it out as well*/
			if (vm_config->memory.size_hpa2 != 0UL) {
				filter_mem_from_sos_e820(vm, vm_config->memory.start_hpa2,
					vm_config->memory.start_hpa2 + vm_config->memory.size_hpa2);
				sos_vm_config->memory.size -= vm_config->memory.size_hpa2;
			}
		}
	}
}

static const struct e820_entry pre_ve820_template[E820_MAX_ENTRIES] = {
	{	/* usable RAM under 1MB */
		.baseaddr = 0x0UL,
		.length   = 0xF0000UL,		/* 960KB */
		.type     = E820_TYPE_RAM
	},
	{	/* mptable/RSDP */
		.baseaddr = 0xF0000UL,		/* 960KB */
		.length   = 0x10000UL,		/* 64KB */
		.type     = E820_TYPE_RESERVED
	},
	{	/* hpa1 */
		.baseaddr = 0x100000UL,		/* 1MB */
		.length   = (MEM_2G - MEM_2M),
		.type     = E820_TYPE_RAM
	},
	{	/* ACPI Reclaim */
		.baseaddr = VIRT_ACPI_DATA_ADDR,/* consecutive from 0x7fff0000UL */
		.length   = (960U * MEM_1K),	/* 960KB */
		.type	  = E820_TYPE_ACPI_RECLAIM
	},
	{	/* ACPI NVS */
		.baseaddr = VIRT_ACPI_NVS_ADDR,	/* consecutive after ACPI Reclaim */
		.length   = 0x10000, 		/* 64KB */
		.type	  = E820_TYPE_ACPI_NVS
	},
	{	/* 32bit PCI hole */
		.baseaddr = 0x80000000UL,	/* 2048MB */
		.length   = MEM_2G,
		.type     = E820_TYPE_RESERVED
	},
};

/**
 * @pre entry != NULL
 */
static inline uint64_t add_ram_entry(struct e820_entry *entry, uint64_t gpa, uint64_t length)
{
	entry->baseaddr = gpa;
	entry->length = length;
	entry->type = E820_TYPE_RAM;
	return round_pde_up(entry->baseaddr + entry->length);
}

/**
 * @pre vm != NULL
 *
 * ve820 layout for pre-launched VM:
 *
 *	 entry0: usable under 1MB
 *	 entry1: reserved for MP Table/ACPI RSDP from 0xf0000 to 0xfffff
 *	 entry2: usable for hpa1 or hpa1_lo from 0x100000
 *	 entry3: ACPI Reclaim from 0x7ff00000 to 0x7ffeffff
 *	 entry4: ACPI NVS from 0x7fff0000 to 0x7fffffff
 *	 entry5: reserved for 32bit PCI hole from 0x80000000 to 0xffffffff
 *	 (entry6): usable for
 *                                         a) hpa1_hi, if hpa1 > 2GB
 *                                         b) hpa2, if (hpa1 + hpa2) < 2GB
 *                                         c) hpa2_lo, if hpa1 < 2GB and (hpa1 + hpa2) > 2GB
 *	 (entry7): usable for
 *                                         a) hpa2, if hpa1 > 2GB
 *                                         b) hpa2_hi, if hpa1 < 2GB and (hpa1 + hpa2) > 2GB
 */
void create_prelaunched_vm_e820(struct acrn_vm *vm)
{
	struct acrn_vm_config *vm_config = get_vm_config(vm->vm_id);
	uint64_t gpa_start = 0x100000000UL;
	uint64_t hpa1_hi_size, hpa2_lo_size;
	uint64_t remaining_hpa2_size = vm_config->memory.size_hpa2;
	uint32_t entry_idx = ENTRY_HPA1_HI;

	vm->e820_entries = pre_vm_e820[vm->vm_id];
	(void)memcpy_s((void *)vm->e820_entries,  E820_MAX_ENTRIES * sizeof(struct e820_entry),
		(const void *)pre_ve820_template, E820_MAX_ENTRIES * sizeof(struct e820_entry));

	/* sanitize entry for hpa1 */
	if (vm_config->memory.size > MEM_2G) {
		/* need to split hpa1 and add an entry for hpa1_hi */
		hpa1_hi_size = vm_config->memory.size - MEM_2G;
		gpa_start = add_ram_entry((vm->e820_entries + entry_idx), gpa_start, hpa1_hi_size);
		entry_idx++;
	} else {
		/* need to revise length of hpa1 entry to its actual size, excluding size of low 1MB and ACPI space */
		vm->e820_entries[ENTRY_HPA1].length = vm_config->memory.size - MEM_2M;
		/* need to set gpa_start for hpa2 */
		gpa_start = vm->e820_entries[ENTRY_HPA1].baseaddr + vm->e820_entries[ENTRY_HPA1].length;
		if ((vm_config->memory.size < MEM_2G)
				&& (remaining_hpa2_size > (MEM_2G - vm_config->memory.size))) {
			/* need to split hpa2 and add an entry for hpa2_lo */
			hpa2_lo_size = remaining_hpa2_size - (MEM_2G - vm_config->memory.size);
			gpa_start = add_ram_entry((vm->e820_entries + entry_idx), gpa_start, hpa2_lo_size);
			remaining_hpa2_size -= hpa2_lo_size;
			entry_idx++;
		}
	}

	/* check whether need an entry for remaining hpa2 */
	if (remaining_hpa2_size > 0UL) {
		gpa_start = add_ram_entry((vm->e820_entries + entry_idx), gpa_start, remaining_hpa2_size);
		entry_idx++;
	}

	vm->e820_entry_num = entry_idx;
}