1 /* 2 * Copyright (c) 2014, ARM Limited and Contributors. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are met: 6 * 7 * Redistributions of source code must retain the above copyright notice, this 8 * list of conditions and the following disclaimer. 9 * 10 * Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 14 * Neither the name of ARM nor the names of its contributors may be used 15 * to endorse or promote products derived from this software without specific 16 * prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 28 * POSSIBILITY OF SUCH DAMAGE. 29 */ 30 31 #include <assert.h> 32 #include <bl_common.h> 33 #include <context_mgmt.h> 34 #include <errno.h> 35 #include <interrupt_mgmt.h> 36 #include <platform.h> 37 #include <stdio.h> 38 39 /******************************************************************************* 40 * Local structure and corresponding array to keep track of the state of the 41 * registered interrupt handlers for each interrupt type. 42 * The field descriptions are: 43 * 44 * 'flags' : Bit[0], Routing model for this interrupt type when execution is 45 * not in EL3 in the secure state. '1' implies that this 46 * interrupt will be routed to EL3. '0' implies that this 47 * interrupt will be routed to the current exception level. 48 * 49 * Bit[1], Routing model for this interrupt type when execution is 50 * not in EL3 in the non-secure state. '1' implies that this 51 * interrupt will be routed to EL3. '0' implies that this 52 * interrupt will be routed to the current exception level. 53 * 54 * All other bits are reserved and SBZ. 55 * 56 * 'scr_el3[2]' : Mapping of the routing model in the 'flags' field to the 57 * value of the SCR_EL3.IRQ or FIQ bit for each security state. 58 * There are two instances of this field corresponding to the 59 * two security states. 60 ******************************************************************************/ 61 typedef struct intr_type_desc { 62 interrupt_type_handler_t handler; 63 uint32_t flags; 64 uint32_t scr_el3[2]; 65 } intr_type_desc_t; 66 67 static intr_type_desc_t intr_type_descs[MAX_INTR_TYPES]; 68 69 /******************************************************************************* 70 * This function validates the interrupt type. EL3 interrupts are currently not 71 * supported. 72 ******************************************************************************/ 73 static int32_t validate_interrupt_type(uint32_t type) 74 { 75 if (type == INTR_TYPE_EL3) 76 return -ENOTSUP; 77 78 if (type != INTR_TYPE_S_EL1 && type != INTR_TYPE_NS) 79 return -EINVAL; 80 81 return 0; 82 } 83 84 /******************************************************************************* 85 * This function validates the routing model for this type of interrupt 86 ******************************************************************************/ 87 static int32_t validate_routing_model(uint32_t type, uint32_t flags) 88 { 89 flags >>= INTR_RM_FLAGS_SHIFT; 90 flags &= INTR_RM_FLAGS_MASK; 91 92 if (type == INTR_TYPE_S_EL1) 93 return validate_sel1_interrupt_rm(flags); 94 95 if (type == INTR_TYPE_NS) 96 return validate_ns_interrupt_rm(flags); 97 98 return -EINVAL; 99 } 100 101 /******************************************************************************* 102 * This function returns the cached copy of the SCR_EL3 which contains the 103 * routing model (expressed through the IRQ and FIQ bits) for a security state 104 * which was stored through a call to 'set_routing_model()' earlier. 105 ******************************************************************************/ 106 uint32_t get_scr_el3_from_routing_model(uint32_t security_state) 107 { 108 uint32_t scr_el3; 109 110 assert(security_state <= NON_SECURE); 111 scr_el3 = intr_type_descs[INTR_TYPE_NS].scr_el3[security_state]; 112 scr_el3 |= intr_type_descs[INTR_TYPE_S_EL1].scr_el3[security_state]; 113 scr_el3 |= intr_type_descs[INTR_TYPE_EL3].scr_el3[security_state]; 114 return scr_el3; 115 } 116 117 /******************************************************************************* 118 * This function uses the 'interrupt_type_flags' parameter to obtain the value 119 * of the trap bit (IRQ/FIQ) in the SCR_EL3 for a security state for this 120 * interrupt type. It uses it to update the SCR_EL3 in the cpu context and the 121 * 'intr_type_desc' for that security state. 122 ******************************************************************************/ 123 static void set_scr_el3_from_rm(uint32_t type, 124 uint32_t interrupt_type_flags, 125 uint32_t security_state) 126 { 127 uint32_t flag, bit_pos; 128 129 flag = get_interrupt_rm_flag(interrupt_type_flags, security_state); 130 bit_pos = plat_interrupt_type_to_line(type, security_state); 131 intr_type_descs[type].scr_el3[security_state] = flag << bit_pos; 132 cm_write_scr_el3_bit(security_state, bit_pos, flag); 133 } 134 135 /******************************************************************************* 136 * This function validates the routing model specified in the 'flags' and 137 * updates internal data structures to reflect the new routing model. It also 138 * updates the copy of SCR_EL3 for each security state with the new routing 139 * model in the 'cpu_context' structure for this cpu. 140 ******************************************************************************/ 141 int32_t set_routing_model(uint32_t type, uint32_t flags) 142 { 143 int32_t rc; 144 145 rc = validate_interrupt_type(type); 146 if (rc) 147 return rc; 148 149 rc = validate_routing_model(type, flags); 150 if (rc) 151 return rc; 152 153 /* Update the routing model in internal data structures */ 154 intr_type_descs[type].flags = flags; 155 set_scr_el3_from_rm(type, flags, SECURE); 156 set_scr_el3_from_rm(type, flags, NON_SECURE); 157 158 return 0; 159 } 160 161 /******************************************************************************* 162 * This function registers a handler for the 'type' of interrupt specified. It 163 * also validates the routing model specified in the 'flags' for this type of 164 * interrupt. 165 ******************************************************************************/ 166 int32_t register_interrupt_type_handler(uint32_t type, 167 interrupt_type_handler_t handler, 168 uint32_t flags) 169 { 170 int32_t rc; 171 172 /* Validate the 'handler' parameter */ 173 if (!handler) 174 return -EINVAL; 175 176 /* Validate the 'flags' parameter */ 177 if (flags & INTR_TYPE_FLAGS_MASK) 178 return -EINVAL; 179 180 /* Check if a handler has already been registered */ 181 if (intr_type_descs[type].handler) 182 return -EALREADY; 183 184 rc = set_routing_model(type, flags); 185 if (rc) 186 return rc; 187 188 /* Save the handler */ 189 intr_type_descs[type].handler = handler; 190 191 return 0; 192 } 193 194 /******************************************************************************* 195 * This function is called when an interrupt is generated and returns the 196 * handler for the interrupt type (if registered). It returns NULL if the 197 * interrupt type is not supported or its handler has not been registered. 198 ******************************************************************************/ 199 interrupt_type_handler_t get_interrupt_type_handler(uint32_t type) 200 { 201 if (validate_interrupt_type(type)) 202 return NULL; 203 204 return intr_type_descs[type].handler; 205 } 206 207