1 /* 2 * Copyright (c) 2014-2023, Arm Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <errno.h> 9 10 #include <common/bl_common.h> 11 #include <bl31/interrupt_mgmt.h> 12 #include <lib/el3_runtime/context_mgmt.h> 13 #include <plat/common/platform.h> 14 15 /******************************************************************************* 16 * Local structure and corresponding array to keep track of the state of the 17 * registered interrupt handlers for each interrupt type. 18 * The field descriptions are: 19 * 20 * 'scr_el3[2]' : Mapping of the routing model in the 'flags' field to the 21 * value of the SCR_EL3.IRQ or FIQ bit for each security state. 22 * There are two instances of this field corresponding to the 23 * two security states. 24 * 25 * 'flags' : Bit[0], Routing model for this interrupt type when execution is 26 * not in EL3 in the secure state. '1' implies that this 27 * interrupt will be routed to EL3. '0' implies that this 28 * interrupt will be routed to the current exception level. 29 * 30 * Bit[1], Routing model for this interrupt type when execution is 31 * not in EL3 in the non-secure state. '1' implies that this 32 * interrupt will be routed to EL3. '0' implies that this 33 * interrupt will be routed to the current exception level. 34 * 35 * All other bits are reserved and SBZ. 36 ******************************************************************************/ 37 typedef struct { 38 interrupt_type_handler_t handler; 39 u_register_t scr_el3[2]; 40 uint32_t flags; 41 } intr_type_desc_t; 42 43 static intr_type_desc_t intr_type_descs[MAX_INTR_TYPES]; 44 45 /******************************************************************************* 46 * This function validates the interrupt type. 47 ******************************************************************************/ 48 static int32_t validate_interrupt_type(uint32_t type) 49 { 50 if (plat_ic_has_interrupt_type(type)) { 51 return 0; 52 } 53 54 return -EINVAL; 55 } 56 57 /******************************************************************************* 58 * This function validates the routing model for this type of interrupt 59 ******************************************************************************/ 60 static int32_t validate_routing_model(uint32_t type, uint32_t flags) 61 { 62 uint32_t rm_flags = (flags >> INTR_RM_FLAGS_SHIFT) & INTR_RM_FLAGS_MASK; 63 64 if (type == INTR_TYPE_S_EL1) 65 return validate_sel1_interrupt_rm(rm_flags); 66 67 if (type == INTR_TYPE_NS) 68 return validate_ns_interrupt_rm(rm_flags); 69 70 if (type == INTR_TYPE_EL3) 71 return validate_el3_interrupt_rm(rm_flags); 72 73 return -EINVAL; 74 } 75 76 /******************************************************************************* 77 * This function returns the cached copy of the SCR_EL3 which contains the 78 * routing model (expressed through the IRQ and FIQ bits) for a security state 79 * which was stored through a call to 'set_routing_model()' earlier. 80 ******************************************************************************/ 81 u_register_t get_scr_el3_from_routing_model(size_t security_state) 82 { 83 u_register_t scr_el3; 84 85 assert(sec_state_is_valid(security_state)); 86 scr_el3 = intr_type_descs[INTR_TYPE_NS].scr_el3[security_state]; 87 scr_el3 |= intr_type_descs[INTR_TYPE_S_EL1].scr_el3[security_state]; 88 scr_el3 |= intr_type_descs[INTR_TYPE_EL3].scr_el3[security_state]; 89 return scr_el3; 90 } 91 92 /******************************************************************************* 93 * This function uses the 'interrupt_type_flags' parameter to obtain the value 94 * of the trap bit (IRQ/FIQ) in the SCR_EL3 for a security state for this 95 * interrupt type. It uses it to update the SCR_EL3 in the cpu context and the 96 * 'intr_type_desc' for that security state. 97 ******************************************************************************/ 98 static void set_scr_el3_from_rm(uint32_t type, 99 uint32_t interrupt_type_flags, 100 uint32_t security_state) 101 { 102 uint32_t flag, bit_pos; 103 104 flag = get_interrupt_rm_flag(interrupt_type_flags, security_state); 105 bit_pos = plat_interrupt_type_to_line(type, security_state); 106 intr_type_descs[type].scr_el3[security_state] = (u_register_t)flag << bit_pos; 107 108 /* 109 * Update scr_el3 only if there is a context available. If not, it 110 * will be updated later during context initialization which will obtain 111 * the scr_el3 value to be used via get_scr_el3_from_routing_model() 112 */ 113 if (cm_get_context(security_state) != NULL) 114 cm_write_scr_el3_bit(security_state, bit_pos, flag); 115 } 116 117 /******************************************************************************* 118 * This function validates the routing model specified in the 'flags' and 119 * updates internal data structures to reflect the new routing model. It also 120 * updates the copy of SCR_EL3 for each security state with the new routing 121 * model in the 'cpu_context' structure for this cpu. 122 ******************************************************************************/ 123 int32_t set_routing_model(uint32_t type, uint32_t flags) 124 { 125 int32_t rc; 126 127 rc = validate_interrupt_type(type); 128 if (rc != 0) 129 return rc; 130 131 rc = validate_routing_model(type, flags); 132 if (rc != 0) 133 return rc; 134 135 /* Update the routing model in internal data structures */ 136 intr_type_descs[type].flags = flags; 137 set_scr_el3_from_rm(type, flags, SECURE); 138 set_scr_el3_from_rm(type, flags, NON_SECURE); 139 140 return 0; 141 } 142 143 /****************************************************************************** 144 * This function disables the routing model of interrupt 'type' from the 145 * specified 'security_state' on the local core. The disable is in effect 146 * till the core powers down or till the next enable for that interrupt 147 * type. 148 *****************************************************************************/ 149 int disable_intr_rm_local(uint32_t type, uint32_t security_state) 150 { 151 uint32_t bit_pos, flag; 152 153 assert(intr_type_descs[type].handler != NULL); 154 155 flag = get_interrupt_rm_flag(INTR_DEFAULT_RM, security_state); 156 157 bit_pos = plat_interrupt_type_to_line(type, security_state); 158 cm_write_scr_el3_bit(security_state, bit_pos, flag); 159 160 return 0; 161 } 162 163 /****************************************************************************** 164 * This function enables the routing model of interrupt 'type' from the 165 * specified 'security_state' on the local core. 166 *****************************************************************************/ 167 int enable_intr_rm_local(uint32_t type, uint32_t security_state) 168 { 169 uint32_t bit_pos, flag; 170 171 assert(intr_type_descs[type].handler != NULL); 172 173 flag = get_interrupt_rm_flag(intr_type_descs[type].flags, 174 security_state); 175 176 bit_pos = plat_interrupt_type_to_line(type, security_state); 177 cm_write_scr_el3_bit(security_state, bit_pos, flag); 178 179 return 0; 180 } 181 182 /******************************************************************************* 183 * This function registers a handler for the 'type' of interrupt specified. It 184 * also validates the routing model specified in the 'flags' for this type of 185 * interrupt. 186 ******************************************************************************/ 187 int32_t register_interrupt_type_handler(uint32_t type, 188 interrupt_type_handler_t handler, 189 uint32_t flags) 190 { 191 int32_t rc; 192 193 /* Validate the 'handler' parameter */ 194 if (handler == NULL) 195 return -EINVAL; 196 197 /* Validate the 'flags' parameter */ 198 if ((flags & INTR_TYPE_FLAGS_MASK) != 0U) 199 return -EINVAL; 200 201 /* Check if a handler has already been registered */ 202 if (intr_type_descs[type].handler != NULL) 203 return -EALREADY; 204 205 rc = set_routing_model(type, flags); 206 if (rc != 0) 207 return rc; 208 209 /* Save the handler */ 210 intr_type_descs[type].handler = handler; 211 212 return 0; 213 } 214 215 /******************************************************************************* 216 * This function is called when an interrupt is generated and returns the 217 * handler for the interrupt type (if registered). It returns NULL if the 218 * interrupt type is not supported or its handler has not been registered. 219 ******************************************************************************/ 220 interrupt_type_handler_t get_interrupt_type_handler(uint32_t type) 221 { 222 if (validate_interrupt_type(type) != 0) { 223 return NULL; 224 } 225 return intr_type_descs[type].handler; 226 } 227 228