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 <arch_helpers.h>
32 #include <bakery_lock.h>
33 #include <mmio.h>
34 #include "juno_def.h"
35 #include "juno_private.h"
36 #include "mhu.h"
37
38 /* SCP MHU secure channel registers */
39 #define SCP_INTR_S_STAT 0x200
40 #define SCP_INTR_S_SET 0x208
41 #define SCP_INTR_S_CLEAR 0x210
42
43 /* CPU MHU secure channel registers */
44 #define CPU_INTR_S_STAT 0x300
45 #define CPU_INTR_S_SET 0x308
46 #define CPU_INTR_S_CLEAR 0x310
47
48 #if IMAGE_BL31
49 #if USE_COHERENT_MEM
50 static bakery_lock_t mhu_secure_lock __attribute__ ((section("tzfw_coherent_mem")));
51 #define LOCK_ARG &mhu_secure_lock
52 #else
53 #define LOCK_ARG JUNO_MHU_BAKERY_ID
54 #endif /*__USE_COHERENT_MEM__ */
55 #else
56 #define LOCK_ARG /* Locks required only for BL3-1 images */
57 #endif /* __IMAGE_BL31__ */
58
mhu_secure_message_start(void)59 void mhu_secure_message_start(void)
60 {
61 juno_lock_get(LOCK_ARG);
62
63 /* Make sure any previous command has finished */
64 while (mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) != 0)
65 ;
66 }
67
mhu_secure_message_send(uint32_t command)68 void mhu_secure_message_send(uint32_t command)
69 {
70 /* Send command to SCP and wait for it to pick it up */
71 mmio_write_32(MHU_BASE + CPU_INTR_S_SET, command);
72 while (mmio_read_32(MHU_BASE + CPU_INTR_S_STAT) != 0)
73 ;
74 }
75
mhu_secure_message_wait(void)76 uint32_t mhu_secure_message_wait(void)
77 {
78 /* Wait for response from SCP */
79 uint32_t response;
80 while (!(response = mmio_read_32(MHU_BASE + SCP_INTR_S_STAT)))
81 ;
82
83 return response;
84 }
85
mhu_secure_message_end(void)86 void mhu_secure_message_end(void)
87 {
88 /* Clear any response we got by writing all ones to the CLEAR register */
89 mmio_write_32(MHU_BASE + SCP_INTR_S_CLEAR, 0xffffffffu);
90
91 juno_lock_release(LOCK_ARG);
92 }
93
mhu_secure_init(void)94 void mhu_secure_init(void)
95 {
96 juno_lock_init(LOCK_ARG);
97
98 /*
99 * Clear the CPU's INTR register to make sure we don't see a stale
100 * or garbage value and think it's a message we've already sent.
101 */
102 mmio_write_32(MHU_BASE + CPU_INTR_S_CLEAR, 0xffffffffu);
103 }
104