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/*
* Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <platform_def.h>
#include <common/debug.h>
#include <drivers/cfi/v2m_flash.h>
#include <lib/psci/psci.h>
#include <lib/mmio.h>
#include <lib/utils.h>
#include <plat_arm.h>
/*
* DRAM1 is used also to load the NS boot loader. For this reason we
* cannot clear the full DRAM1, because in that case we would clear
* the NS images (especially for RESET_TO_BL31 and RESET_TO_SPMIN cases).
* For this reason we reserve 64 MB for the NS images and protect the RAM
* until the end of DRAM1.
* We limit the size of DRAM2 to 1 GB to avoid big delays while booting
*/
#define DRAM1_NS_IMAGE_LIMIT (PLAT_ARM_NS_IMAGE_OFFSET + (32 << TWO_MB_SHIFT))
#define DRAM1_PROTECTED_SIZE (ARM_NS_DRAM1_END+1u - DRAM1_NS_IMAGE_LIMIT)
static mem_region_t arm_ram_ranges[] = {
{DRAM1_NS_IMAGE_LIMIT, DRAM1_PROTECTED_SIZE},
#ifdef AARCH64
{ARM_DRAM2_BASE, 1u << ONE_GB_SHIFT},
#endif
};
/*******************************************************************************
* Function that reads the content of the memory protect variable that
* enables clearing of non secure memory when system boots. This variable
* should be stored in a secure NVRAM.
******************************************************************************/
int arm_psci_read_mem_protect(int *enabled)
{
int tmp;
tmp = *(int *) PLAT_ARM_MEM_PROT_ADDR;
*enabled = (tmp == 1) ? 1 : 0;
return 0;
}
/*******************************************************************************
* Function that writes the content of the memory protect variable that
* enables overwritten of non secure memory when system boots.
******************************************************************************/
int arm_nor_psci_write_mem_protect(int val)
{
unsigned long enable = (val != 0) ? 1UL : 0UL;
if (nor_unlock(PLAT_ARM_MEM_PROT_ADDR) != 0) {
ERROR("unlocking memory protect variable\n");
return -1;
}
if (enable == 1UL) {
/*
* If we want to write a value different than 0
* then we have to erase the full block because
* otherwise we cannot ensure that the value programmed
* into the flash is going to be the same than the value
* requested by the caller
*/
if (nor_erase(PLAT_ARM_MEM_PROT_ADDR) != 0) {
ERROR("erasing block containing memory protect variable\n");
return -1;
}
}
if (nor_word_program(PLAT_ARM_MEM_PROT_ADDR, enable) != 0) {
ERROR("programming memory protection variable\n");
return -1;
}
return 0;
}
/*******************************************************************************
* Function used for required psci operations performed when
* system boots
******************************************************************************/
/*
* PLAT_MEM_PROTECT_VA_FRAME is a address specifically
* selected in a way that is not needed an additional
* translation table for memprotect. It happens because
* we use a chunk of size 2MB and it means that it can
* be mapped in a level 2 table and the level 2 table
* for 0xc0000000 is already used and the entry for
* 0xc0000000 is not used.
*/
#if defined(PLAT_XLAT_TABLES_DYNAMIC)
void arm_nor_psci_do_dyn_mem_protect(void)
{
int enable;
arm_psci_read_mem_protect(&enable);
if (enable == 0)
return;
INFO("PSCI: Overwriting non secure memory\n");
clear_map_dyn_mem_regions(arm_ram_ranges,
ARRAY_SIZE(arm_ram_ranges),
PLAT_ARM_MEM_PROTEC_VA_FRAME,
1 << TWO_MB_SHIFT);
}
#endif
/*******************************************************************************
* Function used for required psci operations performed when
* system boots and dynamic memory is not used.
******************************************************************************/
void arm_nor_psci_do_static_mem_protect(void)
{
int enable;
(void) arm_psci_read_mem_protect(&enable);
if (enable == 0)
return;
INFO("PSCI: Overwriting non secure memory\n");
clear_mem_regions(arm_ram_ranges,
ARRAY_SIZE(arm_ram_ranges));
(void) arm_nor_psci_write_mem_protect(0);
}
/*******************************************************************************
* Function that checks if a region is protected by the memory protect
* mechanism
******************************************************************************/
int arm_psci_mem_protect_chk(uintptr_t base, u_register_t length)
{
return mem_region_in_array_chk(arm_ram_ranges,
ARRAY_SIZE(arm_ram_ranges),
base, length);
}
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