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      1 /*
      2  * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved.
      3  *
      4  * SPDX-License-Identifier: BSD-3-Clause
      5  */
      6 
      7 #include <assert.h>
      8 #include <debug.h>
      9 #include <mmio.h>
     10 #include <stddef.h>
     11 #include <tzc400.h>
     12 #include "tzc_common_private.h"
     13 
     14 /*
     15  * Macros which will be used by common core functions.
     16  */
     17 #define TZC_400_REGION_BASE_LOW_0_OFFSET	0x100
     18 #define TZC_400_REGION_BASE_HIGH_0_OFFSET	0x104
     19 #define TZC_400_REGION_TOP_LOW_0_OFFSET		0x108
     20 #define TZC_400_REGION_TOP_HIGH_0_OFFSET	0x10c
     21 #define TZC_400_REGION_ATTR_0_OFFSET		0x110
     22 #define TZC_400_REGION_ID_ACCESS_0_OFFSET	0x114
     23 
     24 /*
     25  * Implementation defined values used to validate inputs later.
     26  * Filters : max of 4 ; 0 to 3
     27  * Regions : max of 9 ; 0 to 8
     28  * Address width : Values between 32 to 64
     29  */
     30 typedef struct tzc400_instance {
     31 	uintptr_t base;
     32 	uint8_t addr_width;
     33 	uint8_t num_filters;
     34 	uint8_t num_regions;
     35 } tzc400_instance_t;
     36 
     37 tzc400_instance_t tzc400;
     38 
     39 static inline unsigned int _tzc400_read_build_config(uintptr_t base)
     40 {
     41 	return mmio_read_32(base + BUILD_CONFIG_OFF);
     42 }
     43 
     44 static inline unsigned int _tzc400_read_gate_keeper(uintptr_t base)
     45 {
     46 	return mmio_read_32(base + GATE_KEEPER_OFF);
     47 }
     48 
     49 static inline void _tzc400_write_gate_keeper(uintptr_t base, unsigned int val)
     50 {
     51 	mmio_write_32(base + GATE_KEEPER_OFF, val);
     52 }
     53 
     54 /*
     55  * Get the open status information for all filter units.
     56  */
     57 #define get_gate_keeper_os(base)	((_tzc400_read_gate_keeper(base) >>	\
     58 					GATE_KEEPER_OS_SHIFT) &		\
     59 					GATE_KEEPER_OS_MASK)
     60 
     61 
     62 /* Define common core functions used across different TZC peripherals. */
     63 DEFINE_TZC_COMMON_WRITE_ACTION(400, 400)
     64 DEFINE_TZC_COMMON_WRITE_REGION_BASE(400, 400)
     65 DEFINE_TZC_COMMON_WRITE_REGION_TOP(400, 400)
     66 DEFINE_TZC_COMMON_WRITE_REGION_ATTRIBUTES(400, 400)
     67 DEFINE_TZC_COMMON_WRITE_REGION_ID_ACCESS(400, 400)
     68 DEFINE_TZC_COMMON_CONFIGURE_REGION0(400)
     69 DEFINE_TZC_COMMON_CONFIGURE_REGION(400)
     70 
     71 static unsigned int _tzc400_get_gate_keeper(uintptr_t base,
     72 				unsigned int filter)
     73 {
     74 	unsigned int open_status;
     75 
     76 	open_status = get_gate_keeper_os(base);
     77 
     78 	return (open_status >> filter) & GATE_KEEPER_FILTER_MASK;
     79 }
     80 
     81 /* This function is not MP safe. */
     82 static void _tzc400_set_gate_keeper(uintptr_t base,
     83 				unsigned int filter,
     84 				int val)
     85 {
     86 	unsigned int open_status;
     87 
     88 	/* Upper half is current state. Lower half is requested state. */
     89 	open_status = get_gate_keeper_os(base);
     90 
     91 	if (val)
     92 		open_status |=  (1 << filter);
     93 	else
     94 		open_status &= ~(1 << filter);
     95 
     96 	_tzc400_write_gate_keeper(base, (open_status & GATE_KEEPER_OR_MASK) <<
     97 			      GATE_KEEPER_OR_SHIFT);
     98 
     99 	/* Wait here until we see the change reflected in the TZC status. */
    100 	while ((get_gate_keeper_os(base)) != open_status)
    101 		;
    102 }
    103 
    104 void tzc400_set_action(tzc_action_t action)
    105 {
    106 	assert(tzc400.base);
    107 	assert(action <= TZC_ACTION_ERR_INT);
    108 
    109 	/*
    110 	 * - Currently no handler is provided to trap an error via interrupt
    111 	 *   or exception.
    112 	 * - The interrupt action has not been tested.
    113 	 */
    114 	_tzc400_write_action(tzc400.base, action);
    115 }
    116 
    117 void tzc400_init(uintptr_t base)
    118 {
    119 #if DEBUG
    120 	unsigned int tzc400_id;
    121 #endif
    122 	unsigned int tzc400_build;
    123 
    124 	assert(base);
    125 	tzc400.base = base;
    126 
    127 #if DEBUG
    128 	tzc400_id = _tzc_read_peripheral_id(base);
    129 	if (tzc400_id != TZC_400_PERIPHERAL_ID) {
    130 		ERROR("TZC-400 : Wrong device ID (0x%x).\n", tzc400_id);
    131 		panic();
    132 	}
    133 #endif
    134 
    135 	/* Save values we will use later. */
    136 	tzc400_build = _tzc400_read_build_config(tzc400.base);
    137 	tzc400.num_filters = ((tzc400_build >> BUILD_CONFIG_NF_SHIFT) &
    138 			   BUILD_CONFIG_NF_MASK) + 1;
    139 	tzc400.addr_width  = ((tzc400_build >> BUILD_CONFIG_AW_SHIFT) &
    140 			   BUILD_CONFIG_AW_MASK) + 1;
    141 	tzc400.num_regions = ((tzc400_build >> BUILD_CONFIG_NR_SHIFT) &
    142 			   BUILD_CONFIG_NR_MASK) + 1;
    143 }
    144 
    145 /*
    146  * `tzc400_configure_region0` is used to program region 0 into the TrustZone
    147  * controller. Region 0 covers the whole address space that is not mapped
    148  * to any other region, and is enabled on all filters; this cannot be
    149  * changed. This function only changes the access permissions.
    150  */
    151 void tzc400_configure_region0(tzc_region_attributes_t sec_attr,
    152 			   unsigned int ns_device_access)
    153 {
    154 	assert(tzc400.base);
    155 	assert(sec_attr <= TZC_REGION_S_RDWR);
    156 
    157 	_tzc400_configure_region0(tzc400.base, sec_attr, ns_device_access);
    158 }
    159 
    160 /*
    161  * `tzc400_configure_region` is used to program regions into the TrustZone
    162  * controller. A region can be associated with more than one filter. The
    163  * associated filters are passed in as a bitmap (bit0 = filter0).
    164  * NOTE:
    165  * Region 0 is special; it is preferable to use tzc400_configure_region0
    166  * for this region (see comment for that function).
    167  */
    168 void tzc400_configure_region(unsigned int filters,
    169 			  int region,
    170 			  unsigned long long region_base,
    171 			  unsigned long long region_top,
    172 			  tzc_region_attributes_t sec_attr,
    173 			  unsigned int nsaid_permissions)
    174 {
    175 	assert(tzc400.base);
    176 
    177 	/* Do range checks on filters and regions. */
    178 	assert(((filters >> tzc400.num_filters) == 0) &&
    179 	       (region >= 0) && (region < tzc400.num_regions));
    180 
    181 	/*
    182 	 * Do address range check based on TZC configuration. A 64bit address is
    183 	 * the max and expected case.
    184 	 */
    185 	assert(((region_top <= _tzc_get_max_top_addr(tzc400.addr_width)) &&
    186 		(region_base < region_top)));
    187 
    188 	/* region_base and (region_top + 1) must be 4KB aligned */
    189 	assert(((region_base | (region_top + 1)) & (4096 - 1)) == 0);
    190 
    191 	assert(sec_attr <= TZC_REGION_S_RDWR);
    192 
    193 	_tzc400_configure_region(tzc400.base, filters, region, region_base,
    194 						region_top,
    195 						sec_attr, nsaid_permissions);
    196 }
    197 
    198 void tzc400_enable_filters(void)
    199 {
    200 	unsigned int state;
    201 	unsigned int filter;
    202 
    203 	assert(tzc400.base);
    204 
    205 	for (filter = 0; filter < tzc400.num_filters; filter++) {
    206 		state = _tzc400_get_gate_keeper(tzc400.base, filter);
    207 		if (state) {
    208 			/* The TZC filter is already configured. Changing the
    209 			 * programmer's view in an active system can cause
    210 			 * unpredictable behavior therefore panic for now rather
    211 			 * than try to determine whether this is safe in this
    212 			 * instance. See:
    213 			 * http://infocenter.arm.com/help/index.jsp?\
    214 			 * topic=/com.arm.doc.ddi0504c/CJHHECBF.html */
    215 			ERROR("TZC-400 : Filter %d Gatekeeper already"
    216 				" enabled.\n", filter);
    217 			panic();
    218 		}
    219 		_tzc400_set_gate_keeper(tzc400.base, filter, 1);
    220 	}
    221 }
    222 
    223 void tzc400_disable_filters(void)
    224 {
    225 	unsigned int filter;
    226 
    227 	assert(tzc400.base);
    228 
    229 	/*
    230 	 * We don't do the same state check as above as the Gatekeepers are
    231 	 * disabled after reset.
    232 	 */
    233 	for (filter = 0; filter < tzc400.num_filters; filter++)
    234 		_tzc400_set_gate_keeper(tzc400.base, filter, 0);
    235 }
    236