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 68 if (type == INTR_TYPE_NS) { 69 return validate_ns_interrupt_rm(rm_flags); 70 } 71 72 if (type == INTR_TYPE_EL3) { 73 return validate_el3_interrupt_rm(rm_flags); 74 } 75 76 return -EINVAL; 77 } 78 79 /******************************************************************************* 80 * This function returns the cached copy of the SCR_EL3 which contains the 81 * routing model (expressed through the IRQ and FIQ bits) for a security state 82 * which was stored through a call to 'set_routing_model()' earlier. 83 ******************************************************************************/ 84 u_register_t get_scr_el3_from_routing_model(size_t security_state) 85 { 86 u_register_t scr_el3; 87 88 assert(sec_state_is_valid(security_state)); 89 scr_el3 = intr_type_descs[INTR_TYPE_NS].scr_el3[security_state]; 90 scr_el3 |= intr_type_descs[INTR_TYPE_S_EL1].scr_el3[security_state]; 91 scr_el3 |= intr_type_descs[INTR_TYPE_EL3].scr_el3[security_state]; 92 return scr_el3; 93 } 94 95 /******************************************************************************* 96 * This function uses the 'interrupt_type_flags' parameter to obtain the value 97 * of the trap bit (IRQ/FIQ) in the SCR_EL3 for a security state for this 98 * interrupt type. It uses it to update the SCR_EL3 in the cpu context and the 99 * 'intr_type_desc' for that security state. 100 ******************************************************************************/ 101 static void set_scr_el3_from_rm(uint32_t type, 102 uint32_t interrupt_type_flags, 103 uint32_t security_state) 104 { 105 uint32_t flag, bit_pos; 106 107 flag = get_interrupt_rm_flag(interrupt_type_flags, security_state); 108 bit_pos = plat_interrupt_type_to_line(type, security_state); 109 intr_type_descs[type].scr_el3[security_state] = (u_register_t)flag << bit_pos; 110 111 /* 112 * Update scr_el3 only if there is a context available. If not, it 113 * will be updated later during context initialization which will obtain 114 * the scr_el3 value to be used via get_scr_el3_from_routing_model() 115 */ 116 if (cm_get_context(security_state) != NULL) { 117 cm_write_scr_el3_bit(security_state, bit_pos, flag); 118 } 119 } 120 121 /******************************************************************************* 122 * This function validates the routing model specified in the 'flags' and 123 * updates internal data structures to reflect the new routing model. It also 124 * updates the copy of SCR_EL3 for each security state with the new routing 125 * model in the 'cpu_context' structure for this cpu. 126 ******************************************************************************/ 127 int32_t set_routing_model(uint32_t type, uint32_t flags) 128 { 129 int32_t rc; 130 131 rc = validate_interrupt_type(type); 132 if (rc != 0) { 133 return rc; 134 } 135 136 rc = validate_routing_model(type, flags); 137 if (rc != 0) { 138 return rc; 139 } 140 141 /* Update the routing model in internal data structures */ 142 intr_type_descs[type].flags = flags; 143 set_scr_el3_from_rm(type, flags, SECURE); 144 set_scr_el3_from_rm(type, flags, NON_SECURE); 145 146 return 0; 147 } 148 149 /****************************************************************************** 150 * This function disables the routing model of interrupt 'type' from the 151 * specified 'security_state' on the local core. The disable is in effect 152 * till the core powers down or till the next enable for that interrupt 153 * type. 154 *****************************************************************************/ 155 int disable_intr_rm_local(uint32_t type, uint32_t security_state) 156 { 157 uint32_t bit_pos, flag; 158 159 assert(intr_type_descs[type].handler != NULL); 160 161 flag = get_interrupt_rm_flag(INTR_DEFAULT_RM, security_state); 162 163 bit_pos = plat_interrupt_type_to_line(type, security_state); 164 cm_write_scr_el3_bit(security_state, bit_pos, flag); 165 166 return 0; 167 } 168 169 /****************************************************************************** 170 * This function enables the routing model of interrupt 'type' from the 171 * specified 'security_state' on the local core. 172 *****************************************************************************/ 173 int enable_intr_rm_local(uint32_t type, uint32_t security_state) 174 { 175 uint32_t bit_pos, flag; 176 177 assert(intr_type_descs[type].handler != NULL); 178 179 flag = get_interrupt_rm_flag(intr_type_descs[type].flags, 180 security_state); 181 182 bit_pos = plat_interrupt_type_to_line(type, security_state); 183 cm_write_scr_el3_bit(security_state, bit_pos, flag); 184 185 return 0; 186 } 187 188 /******************************************************************************* 189 * This function registers a handler for the 'type' of interrupt specified. It 190 * also validates the routing model specified in the 'flags' for this type of 191 * interrupt. 192 ******************************************************************************/ 193 int32_t register_interrupt_type_handler(uint32_t type, 194 interrupt_type_handler_t handler, 195 uint32_t flags) 196 { 197 int32_t rc; 198 199 /* Validate the 'handler' parameter */ 200 if (handler == NULL) { 201 return -EINVAL; 202 } 203 204 /* Validate the 'flags' parameter */ 205 if ((flags & INTR_TYPE_FLAGS_MASK) != 0U) { 206 return -EINVAL; 207 } 208 /* Check if a handler has already been registered */ 209 if (intr_type_descs[type].handler != NULL) { 210 return -EALREADY; 211 } 212 rc = set_routing_model(type, flags); 213 if (rc != 0) { 214 return rc; 215 } 216 217 /* Save the handler */ 218 intr_type_descs[type].handler = handler; 219 220 return 0; 221 } 222 223 /******************************************************************************* 224 * This function is called when an interrupt is generated and returns the 225 * handler for the interrupt type (if registered). It returns NULL if the 226 * interrupt type is not supported or its handler has not been registered. 227 ******************************************************************************/ 228 interrupt_type_handler_t get_interrupt_type_handler(uint32_t type) 229 { 230 if (validate_interrupt_type(type) != 0) { 231 return NULL; 232 } 233 return intr_type_descs[type].handler; 234 } 235 236