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