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 intr_type_desc {
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 ******************************************************************************/
validate_interrupt_type(uint32_t type)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 ******************************************************************************/
validate_routing_model(uint32_t type,uint32_t flags)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 ******************************************************************************/
get_scr_el3_from_routing_model(uint32_t security_state)81 u_register_t get_scr_el3_from_routing_model(uint32_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 ******************************************************************************/
set_scr_el3_from_rm(uint32_t type,uint32_t interrupt_type_flags,uint32_t security_state)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 ******************************************************************************/
set_routing_model(uint32_t type,uint32_t flags)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 *****************************************************************************/
disable_intr_rm_local(uint32_t type,uint32_t security_state)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 *****************************************************************************/
enable_intr_rm_local(uint32_t type,uint32_t security_state)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 ******************************************************************************/
register_interrupt_type_handler(uint32_t type,interrupt_type_handler_t handler,uint32_t flags)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 ******************************************************************************/
get_interrupt_type_handler(uint32_t type)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
