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 ******************************************************************************/
validate_interrupt_type(uint32_t type)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 ******************************************************************************/
validate_routing_model(uint32_t type,uint32_t flags)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 ******************************************************************************/
get_scr_el3_from_routing_model(uint32_t security_state)106 uint32_t get_scr_el3_from_routing_model(uint32_t security_state)
107 {
108 uint32_t scr_el3;
109
110 assert(sec_state_is_valid(security_state));
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 ******************************************************************************/
set_scr_el3_from_rm(uint32_t type,uint32_t interrupt_type_flags,uint32_t security_state)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 ******************************************************************************/
set_routing_model(uint32_t type,uint32_t flags)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 disables the routing model of interrupt 'type' from the
163 * specified 'security_state' on the local core. The disable is in effect
164 * till the core powers down or till the next enable for that interrupt
165 * type.
166 *****************************************************************************/
disable_intr_rm_local(uint32_t type,uint32_t security_state)167 int disable_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);
172
173 flag = get_interrupt_rm_flag(INTR_DEFAULT_RM, 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 enables the routing model of interrupt 'type' from the
183 * specified 'security_state' on the local core.
184 *****************************************************************************/
enable_intr_rm_local(uint32_t type,uint32_t security_state)185 int enable_intr_rm_local(uint32_t type, uint32_t security_state)
186 {
187 uint32_t bit_pos, flag;
188
189 assert(intr_type_descs[type].handler);
190
191 flag = get_interrupt_rm_flag(intr_type_descs[type].flags,
192 security_state);
193
194 bit_pos = plat_interrupt_type_to_line(type, security_state);
195 cm_write_scr_el3_bit(security_state, bit_pos, flag);
196
197 return 0;
198 }
199
200 /*******************************************************************************
201 * This function registers a handler for the 'type' of interrupt specified. It
202 * also validates the routing model specified in the 'flags' for this type of
203 * interrupt.
204 ******************************************************************************/
register_interrupt_type_handler(uint32_t type,interrupt_type_handler_t handler,uint32_t flags)205 int32_t register_interrupt_type_handler(uint32_t type,
206 interrupt_type_handler_t handler,
207 uint32_t flags)
208 {
209 int32_t rc;
210
211 /* Validate the 'handler' parameter */
212 if (!handler)
213 return -EINVAL;
214
215 /* Validate the 'flags' parameter */
216 if (flags & INTR_TYPE_FLAGS_MASK)
217 return -EINVAL;
218
219 /* Check if a handler has already been registered */
220 if (intr_type_descs[type].handler)
221 return -EALREADY;
222
223 rc = set_routing_model(type, flags);
224 if (rc)
225 return rc;
226
227 /* Save the handler */
228 intr_type_descs[type].handler = handler;
229
230 return 0;
231 }
232
233 /*******************************************************************************
234 * This function is called when an interrupt is generated and returns the
235 * handler for the interrupt type (if registered). It returns NULL if the
236 * interrupt type is not supported or its handler has not been registered.
237 ******************************************************************************/
get_interrupt_type_handler(uint32_t type)238 interrupt_type_handler_t get_interrupt_type_handler(uint32_t type)
239 {
240 if (validate_interrupt_type(type))
241 return NULL;
242
243 return intr_type_descs[type].handler;
244 }
245
246