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