/*
 * Copyright (C) 2011-2016 ARM Limited. All rights reserved.
 * 
 * This program is free software and is provided to you under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation, and any use by you of this program is subject to the terms of such GNU licence.
 * 
 * A copy of the licence is included with the program, and can also be obtained from Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include "mali_kernel_common.h"
#include "mali_osk.h"
#include "mali_ukk.h"
#include "mali_uk_types.h"
#include "mali_mmu_page_directory.h"
#include "mali_memory.h"
#include "mali_l2_cache.h"

static _mali_osk_errcode_t fill_page(mali_io_address mapping, u32 data);

u32 mali_allocate_empty_page(mali_io_address *virt_addr)
{
	_mali_osk_errcode_t err;
	mali_io_address mapping;
	mali_dma_addr address;

	if (_MALI_OSK_ERR_OK != mali_mmu_get_table_page(&address, &mapping)) {
		/* Allocation failed */
		MALI_DEBUG_PRINT(2, ("Mali MMU: Failed to get table page for empty pgdir\n"));
		return 0;
	}

	MALI_DEBUG_ASSERT_POINTER(mapping);

	err = fill_page(mapping, 0);
	if (_MALI_OSK_ERR_OK != err) {
		mali_mmu_release_table_page(address, mapping);
		MALI_DEBUG_PRINT(2, ("Mali MMU: Failed to zero page\n"));
		return 0;
	}

	*virt_addr = mapping;
	return address;
}

void mali_free_empty_page(mali_dma_addr address, mali_io_address virt_addr)
{
	if (MALI_INVALID_PAGE != address) {
		mali_mmu_release_table_page(address, virt_addr);
	}
}

_mali_osk_errcode_t mali_create_fault_flush_pages(mali_dma_addr *page_directory,
		mali_io_address *page_directory_mapping,
		mali_dma_addr *page_table, mali_io_address *page_table_mapping,
		mali_dma_addr *data_page, mali_io_address *data_page_mapping)
{
	_mali_osk_errcode_t err;

	err = mali_mmu_get_table_page(data_page, data_page_mapping);
	if (_MALI_OSK_ERR_OK == err) {
		err = mali_mmu_get_table_page(page_table, page_table_mapping);
		if (_MALI_OSK_ERR_OK == err) {
			err = mali_mmu_get_table_page(page_directory, page_directory_mapping);
			if (_MALI_OSK_ERR_OK == err) {
				fill_page(*data_page_mapping, 0);
				fill_page(*page_table_mapping, *data_page | MALI_MMU_FLAGS_DEFAULT);
				fill_page(*page_directory_mapping, *page_table | MALI_MMU_FLAGS_PRESENT);
				MALI_SUCCESS;
			}
			mali_mmu_release_table_page(*page_table, *page_table_mapping);
			*page_table = MALI_INVALID_PAGE;
		}
		mali_mmu_release_table_page(*data_page, *data_page_mapping);
		*data_page = MALI_INVALID_PAGE;
	}
	return err;
}

void mali_destroy_fault_flush_pages(
	mali_dma_addr *page_directory, mali_io_address *page_directory_mapping,
	mali_dma_addr *page_table, mali_io_address *page_table_mapping,
	mali_dma_addr *data_page, mali_io_address *data_page_mapping)
{
	if (MALI_INVALID_PAGE != *page_directory) {
		mali_mmu_release_table_page(*page_directory, *page_directory_mapping);
		*page_directory = MALI_INVALID_PAGE;
		*page_directory_mapping = NULL;
	}

	if (MALI_INVALID_PAGE != *page_table) {
		mali_mmu_release_table_page(*page_table, *page_table_mapping);
		*page_table = MALI_INVALID_PAGE;
		*page_table_mapping = NULL;
	}

	if (MALI_INVALID_PAGE != *data_page) {
		mali_mmu_release_table_page(*data_page, *data_page_mapping);
		*data_page = MALI_INVALID_PAGE;
		*data_page_mapping = NULL;
	}
}

static _mali_osk_errcode_t fill_page(mali_io_address mapping, u32 data)
{
	int i;
	MALI_DEBUG_ASSERT_POINTER(mapping);

	for (i = 0; i < MALI_MMU_PAGE_SIZE / 4; i++) {
		_mali_osk_mem_iowrite32_relaxed(mapping, i * sizeof(u32), data);
	}
	_mali_osk_mem_barrier();
	MALI_SUCCESS;
}

_mali_osk_errcode_t mali_mmu_pagedir_map(struct mali_page_directory *pagedir, u32 mali_address, u32 size)
{
	const int first_pde = MALI_MMU_PDE_ENTRY(mali_address);
	const int last_pde = MALI_MMU_PDE_ENTRY(mali_address + size - 1);
	_mali_osk_errcode_t err;
	mali_io_address pde_mapping;
	mali_dma_addr pde_phys;
	int i, page_count;
	u32 start_address;
	if (last_pde < first_pde)
		return _MALI_OSK_ERR_INVALID_ARGS;

	for (i = first_pde; i <= last_pde; i++) {
		if (0 == (_mali_osk_mem_ioread32(pagedir->page_directory_mapped,
						 i * sizeof(u32)) & MALI_MMU_FLAGS_PRESENT)) {
			/* Page table not present */
			MALI_DEBUG_ASSERT(0 == pagedir->page_entries_usage_count[i]);
			MALI_DEBUG_ASSERT(NULL == pagedir->page_entries_mapped[i]);

			err = mali_mmu_get_table_page(&pde_phys, &pde_mapping);
			if (_MALI_OSK_ERR_OK != err) {
				MALI_PRINT_ERROR(("Failed to allocate page table page.\n"));
				return err;
			}
			pagedir->page_entries_mapped[i] = pde_mapping;

			/* Update PDE, mark as present */
			_mali_osk_mem_iowrite32_relaxed(pagedir->page_directory_mapped, i * sizeof(u32),
							pde_phys | MALI_MMU_FLAGS_PRESENT);

			MALI_DEBUG_ASSERT(0 == pagedir->page_entries_usage_count[i]);
		}

		if (first_pde == last_pde) {
			pagedir->page_entries_usage_count[i] += size / MALI_MMU_PAGE_SIZE;
		} else if (i == first_pde) {
			start_address = i * MALI_MMU_VIRTUAL_PAGE_SIZE;
			page_count = (start_address + MALI_MMU_VIRTUAL_PAGE_SIZE - mali_address) / MALI_MMU_PAGE_SIZE;
			pagedir->page_entries_usage_count[i] += page_count;
		} else if (i == last_pde) {
			start_address = i * MALI_MMU_VIRTUAL_PAGE_SIZE;
			page_count = (mali_address + size - start_address) / MALI_MMU_PAGE_SIZE;
			pagedir->page_entries_usage_count[i] += page_count;
		} else {
			pagedir->page_entries_usage_count[i] = 1024;
		}
	}
	_mali_osk_write_mem_barrier();

	return _MALI_OSK_ERR_OK;
}

MALI_STATIC_INLINE void mali_mmu_zero_pte(mali_io_address page_table, u32 mali_address, u32 size)
{
	int i;
	const int first_pte = MALI_MMU_PTE_ENTRY(mali_address);
	const int last_pte = MALI_MMU_PTE_ENTRY(mali_address + size - 1);

	for (i = first_pte; i <= last_pte; i++) {
		_mali_osk_mem_iowrite32_relaxed(page_table, i * sizeof(u32), 0);
	}
}

static u32 mali_page_directory_get_phys_address(struct mali_page_directory *pagedir, u32 index)
{
	return (_mali_osk_mem_ioread32(pagedir->page_directory_mapped,
				       index * sizeof(u32)) & ~MALI_MMU_FLAGS_MASK);
}


_mali_osk_errcode_t mali_mmu_pagedir_unmap(struct mali_page_directory *pagedir, u32 mali_address, u32 size)
{
	const int first_pde = MALI_MMU_PDE_ENTRY(mali_address);
	const int last_pde = MALI_MMU_PDE_ENTRY(mali_address + size - 1);
	u32 left = size;
	int i;
	mali_bool pd_changed = MALI_FALSE;
	u32 pages_to_invalidate[3]; /* hard-coded to 3: max two pages from the PT level plus max one page from PD level */
	u32 num_pages_inv = 0;
	mali_bool invalidate_all = MALI_FALSE; /* safety mechanism in case page_entries_usage_count is unreliable */

	/* For all page directory entries in range. */
	for (i = first_pde; i <= last_pde; i++) {
		u32 size_in_pde, offset;

		MALI_DEBUG_ASSERT_POINTER(pagedir->page_entries_mapped[i]);
		MALI_DEBUG_ASSERT(0 != pagedir->page_entries_usage_count[i]);

		/* Offset into page table, 0 if mali_address is 4MiB aligned */
		offset = (mali_address & (MALI_MMU_VIRTUAL_PAGE_SIZE - 1));
		if (left < MALI_MMU_VIRTUAL_PAGE_SIZE - offset) {
			size_in_pde = left;
		} else {
			size_in_pde = MALI_MMU_VIRTUAL_PAGE_SIZE - offset;
		}

		pagedir->page_entries_usage_count[i] -= size_in_pde / MALI_MMU_PAGE_SIZE;

		/* If entire page table is unused, free it */
		if (0 == pagedir->page_entries_usage_count[i]) {
			u32 page_phys;
			void *page_virt;
			MALI_DEBUG_PRINT(4, ("Releasing page table as this is the last reference\n"));
			/* last reference removed, no need to zero out each PTE  */

			page_phys = MALI_MMU_ENTRY_ADDRESS(_mali_osk_mem_ioread32(pagedir->page_directory_mapped, i * sizeof(u32)));
			page_virt = pagedir->page_entries_mapped[i];
			pagedir->page_entries_mapped[i] = NULL;
			_mali_osk_mem_iowrite32_relaxed(pagedir->page_directory_mapped, i * sizeof(u32), 0);

			mali_mmu_release_table_page(page_phys, page_virt);
			pd_changed = MALI_TRUE;
		} else {
			MALI_DEBUG_ASSERT(num_pages_inv < 2);
			if (num_pages_inv < 2) {
				pages_to_invalidate[num_pages_inv] = mali_page_directory_get_phys_address(pagedir, i);
				num_pages_inv++;
			} else {
				invalidate_all = MALI_TRUE;
			}

			/* If part of the page table is still in use, zero the relevant PTEs */
			mali_mmu_zero_pte(pagedir->page_entries_mapped[i], mali_address, size_in_pde);
		}

		left -= size_in_pde;
		mali_address += size_in_pde;
	}
	_mali_osk_write_mem_barrier();

	/* L2 pages invalidation */
	if (MALI_TRUE == pd_changed) {
		MALI_DEBUG_ASSERT(num_pages_inv < 3);
		if (num_pages_inv < 3) {
			pages_to_invalidate[num_pages_inv] = pagedir->page_directory;
			num_pages_inv++;
		} else {
			invalidate_all = MALI_TRUE;
		}
	}

	if (invalidate_all) {
		mali_l2_cache_invalidate_all();
	} else {
		mali_l2_cache_invalidate_all_pages(pages_to_invalidate, num_pages_inv);
	}

	MALI_SUCCESS;
}

struct mali_page_directory *mali_mmu_pagedir_alloc(void)
{
	struct mali_page_directory *pagedir;
	_mali_osk_errcode_t err;
	mali_dma_addr phys;

	pagedir = _mali_osk_calloc(1, sizeof(struct mali_page_directory));
	if (NULL == pagedir) {
		return NULL;
	}

	err = mali_mmu_get_table_page(&phys, &pagedir->page_directory_mapped);
	if (_MALI_OSK_ERR_OK != err) {
		_mali_osk_free(pagedir);
		return NULL;
	}

	pagedir->page_directory = (u32)phys;

	/* Zero page directory */
	fill_page(pagedir->page_directory_mapped, 0);

	return pagedir;
}

void mali_mmu_pagedir_free(struct mali_page_directory *pagedir)
{
	const int num_page_table_entries = sizeof(pagedir->page_entries_mapped) / sizeof(pagedir->page_entries_mapped[0]);
	int i;

	/* Free referenced page tables and zero PDEs. */
	for (i = 0; i < num_page_table_entries; i++) {
		if (pagedir->page_directory_mapped && (_mali_osk_mem_ioread32(
				pagedir->page_directory_mapped,
				sizeof(u32)*i) & MALI_MMU_FLAGS_PRESENT)) {
			mali_dma_addr phys = _mali_osk_mem_ioread32(pagedir->page_directory_mapped,
					     i * sizeof(u32)) & ~MALI_MMU_FLAGS_MASK;
			_mali_osk_mem_iowrite32_relaxed(pagedir->page_directory_mapped, i * sizeof(u32), 0);
			mali_mmu_release_table_page(phys, pagedir->page_entries_mapped[i]);
		}
	}
	_mali_osk_write_mem_barrier();

	/* Free the page directory page. */
	mali_mmu_release_table_page(pagedir->page_directory, pagedir->page_directory_mapped);

	_mali_osk_free(pagedir);
}


void mali_mmu_pagedir_update(struct mali_page_directory *pagedir, u32 mali_address,
			     mali_dma_addr phys_address, u32 size, u32 permission_bits)
{
	u32 end_address = mali_address + size;
	u32 mali_phys = (u32)phys_address;

	/* Map physical pages into MMU page tables */
	for (; mali_address < end_address; mali_address += MALI_MMU_PAGE_SIZE, mali_phys += MALI_MMU_PAGE_SIZE) {
		MALI_DEBUG_ASSERT_POINTER(pagedir->page_entries_mapped[MALI_MMU_PDE_ENTRY(mali_address)]);
		_mali_osk_mem_iowrite32_relaxed(pagedir->page_entries_mapped[MALI_MMU_PDE_ENTRY(mali_address)],
						MALI_MMU_PTE_ENTRY(mali_address) * sizeof(u32),
						mali_phys | permission_bits);
	}
}

void mali_mmu_pagedir_diag(struct mali_page_directory *pagedir, u32 fault_addr)
{
#if defined(DEBUG)
	u32 pde_index, pte_index;
	u32 pde, pte;

	pde_index = MALI_MMU_PDE_ENTRY(fault_addr);
	pte_index = MALI_MMU_PTE_ENTRY(fault_addr);


	pde = _mali_osk_mem_ioread32(pagedir->page_directory_mapped,
				     pde_index * sizeof(u32));


	if (pde & MALI_MMU_FLAGS_PRESENT) {
		u32 pte_addr = MALI_MMU_ENTRY_ADDRESS(pde);

		pte = _mali_osk_mem_ioread32(pagedir->page_entries_mapped[pde_index],
					     pte_index * sizeof(u32));

		MALI_DEBUG_PRINT(2, ("\tMMU: %08x: Page table present: %08x\n"
				     "\t\tPTE: %08x, page %08x is %s\n",
				     fault_addr, pte_addr, pte,
				     MALI_MMU_ENTRY_ADDRESS(pte),
				     pte & MALI_MMU_FLAGS_DEFAULT ? "rw" : "not present"));
	} else {
		MALI_DEBUG_PRINT(2, ("\tMMU: %08x: Page table not present: %08x\n",
				     fault_addr, pde));
	}
#else
	MALI_IGNORE(pagedir);
	MALI_IGNORE(fault_addr);
#endif
}

/* For instrumented */
struct dump_info {
	u32 buffer_left;
	u32 register_writes_size;
	u32 page_table_dump_size;
	u32 *buffer;
};

static _mali_osk_errcode_t writereg(u32 where, u32 what, const char *comment, struct dump_info *info)
{
	if (NULL != info) {
		info->register_writes_size += sizeof(u32) * 2; /* two 32-bit words */

		if (NULL != info->buffer) {
			/* check that we have enough space */
			if (info->buffer_left < sizeof(u32) * 2) MALI_ERROR(_MALI_OSK_ERR_NOMEM);

			*info->buffer = where;
			info->buffer++;

			*info->buffer = what;
			info->buffer++;

			info->buffer_left -= sizeof(u32) * 2;
		}
	}

	MALI_SUCCESS;
}

static _mali_osk_errcode_t mali_mmu_dump_page(mali_io_address page, u32 phys_addr, struct dump_info *info)
{
	if (NULL != info) {
		/* 4096 for the page and 4 bytes for the address */
		const u32 page_size_in_elements = MALI_MMU_PAGE_SIZE / 4;
		const u32 page_size_in_bytes = MALI_MMU_PAGE_SIZE;
		const u32 dump_size_in_bytes = MALI_MMU_PAGE_SIZE + 4;

		info->page_table_dump_size += dump_size_in_bytes;

		if (NULL != info->buffer) {
			if (info->buffer_left < dump_size_in_bytes) MALI_ERROR(_MALI_OSK_ERR_NOMEM);

			*info->buffer = phys_addr;
			info->buffer++;

			_mali_osk_memcpy(info->buffer, page, page_size_in_bytes);
			info->buffer += page_size_in_elements;

			info->buffer_left -= dump_size_in_bytes;
		}
	}

	MALI_SUCCESS;
}

static _mali_osk_errcode_t dump_mmu_page_table(struct mali_page_directory *pagedir, struct dump_info *info)
{
	MALI_DEBUG_ASSERT_POINTER(pagedir);
	MALI_DEBUG_ASSERT_POINTER(info);

	if (NULL != pagedir->page_directory_mapped) {
		int i;

		MALI_CHECK_NO_ERROR(
			mali_mmu_dump_page(pagedir->page_directory_mapped, pagedir->page_directory, info)
		);

		for (i = 0; i < 1024; i++) {
			if (NULL != pagedir->page_entries_mapped[i]) {
				MALI_CHECK_NO_ERROR(
					mali_mmu_dump_page(pagedir->page_entries_mapped[i],
							   _mali_osk_mem_ioread32(pagedir->page_directory_mapped,
									   i * sizeof(u32)) & ~MALI_MMU_FLAGS_MASK, info)
				);
			}
		}
	}

	MALI_SUCCESS;
}

static _mali_osk_errcode_t dump_mmu_registers(struct mali_page_directory *pagedir, struct dump_info *info)
{
	MALI_CHECK_NO_ERROR(writereg(0x00000000, pagedir->page_directory,
				     "set the page directory address", info));
	MALI_CHECK_NO_ERROR(writereg(0x00000008, 4, "zap???", info));
	MALI_CHECK_NO_ERROR(writereg(0x00000008, 0, "enable paging", info));
	MALI_SUCCESS;
}

_mali_osk_errcode_t _mali_ukk_query_mmu_page_table_dump_size(_mali_uk_query_mmu_page_table_dump_size_s *args)
{
	struct dump_info info = { 0, 0, 0, NULL };
	struct mali_session_data *session_data;

	session_data = (struct mali_session_data *)(uintptr_t)(args->ctx);
	MALI_DEBUG_ASSERT_POINTER(session_data);
	MALI_DEBUG_ASSERT_POINTER(args);

	MALI_CHECK_NO_ERROR(dump_mmu_registers(session_data->page_directory, &info));
	MALI_CHECK_NO_ERROR(dump_mmu_page_table(session_data->page_directory, &info));
	args->size = info.register_writes_size + info.page_table_dump_size;
	MALI_SUCCESS;
}

_mali_osk_errcode_t _mali_ukk_dump_mmu_page_table(_mali_uk_dump_mmu_page_table_s *args)
{
	struct dump_info info = { 0, 0, 0, NULL };
	struct mali_session_data *session_data;

	MALI_DEBUG_ASSERT_POINTER(args);

	session_data = (struct mali_session_data *)(uintptr_t)(args->ctx);
	MALI_DEBUG_ASSERT_POINTER(session_data);

	info.buffer_left = args->size;
	info.buffer = (u32 *)(uintptr_t)args->buffer;

	args->register_writes = (uintptr_t)info.buffer;
	MALI_CHECK_NO_ERROR(dump_mmu_registers(session_data->page_directory, &info));

	args->page_table_dump = (uintptr_t)info.buffer;
	MALI_CHECK_NO_ERROR(dump_mmu_page_table(session_data->page_directory, &info));

	args->register_writes_size = info.register_writes_size;
	args->page_table_dump_size = info.page_table_dump_size;

	MALI_SUCCESS;
}