1 /*
2 * Copyright (c) 2018-2021, ARM Limited and Contributors. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <arch.h>
8 #include <arch_helpers.h>
9 #include <assert.h>
10 #include <errno.h>
11 #include <lib/el3_runtime/context_mgmt.h>
12 #include <lib/spinlock.h>
13 #include <lib/xlat_tables/xlat_tables_v2.h>
14 #include <platform_def.h>
15 #include <plat/common/platform.h>
16
17 #include "spm_common.h"
18 #include "spm_shim_private.h"
19
20 /* Lock used for SP_MEMORY_ATTRIBUTES_GET and SP_MEMORY_ATTRIBUTES_SET */
21 static spinlock_t mem_attr_smc_lock;
22
23 /*
24 * Attributes are encoded using a different format in the SMC interface than in
25 * the Trusted Firmware, where the mmap_attr_t enum type is used. This function
26 * converts an attributes value from the SMC format to the mmap_attr_t format by
27 * setting MT_RW/MT_RO, MT_USER/MT_PRIVILEGED and MT_EXECUTE/MT_EXECUTE_NEVER.
28 * The other fields are left as 0 because they are ignored by the function
29 * xlat_change_mem_attributes_ctx().
30 */
smc_attr_to_mmap_attr(unsigned int attributes)31 static unsigned int smc_attr_to_mmap_attr(unsigned int attributes)
32 {
33 unsigned int tf_attr = 0U;
34
35 unsigned int access = (attributes & SP_MEMORY_ATTRIBUTES_ACCESS_MASK)
36 >> SP_MEMORY_ATTRIBUTES_ACCESS_SHIFT;
37
38 if (access == SP_MEMORY_ATTRIBUTES_ACCESS_RW) {
39 tf_attr |= MT_RW | MT_USER;
40 } else if (access == SP_MEMORY_ATTRIBUTES_ACCESS_RO) {
41 tf_attr |= MT_RO | MT_USER;
42 } else {
43 /* Other values are reserved. */
44 assert(access == SP_MEMORY_ATTRIBUTES_ACCESS_NOACCESS);
45 /* The only requirement is that there's no access from EL0 */
46 tf_attr |= MT_RO | MT_PRIVILEGED;
47 }
48
49 if ((attributes & SP_MEMORY_ATTRIBUTES_NON_EXEC) == 0) {
50 tf_attr |= MT_EXECUTE;
51 } else {
52 tf_attr |= MT_EXECUTE_NEVER;
53 }
54
55 return tf_attr;
56 }
57
58 /*
59 * This function converts attributes from the Trusted Firmware format into the
60 * SMC interface format.
61 */
smc_mmap_to_smc_attr(unsigned int attr)62 static unsigned int smc_mmap_to_smc_attr(unsigned int attr)
63 {
64 unsigned int smc_attr = 0U;
65
66 unsigned int data_access;
67
68 if ((attr & MT_USER) == 0) {
69 /* No access from EL0. */
70 data_access = SP_MEMORY_ATTRIBUTES_ACCESS_NOACCESS;
71 } else {
72 if ((attr & MT_RW) != 0) {
73 assert(MT_TYPE(attr) != MT_DEVICE);
74 data_access = SP_MEMORY_ATTRIBUTES_ACCESS_RW;
75 } else {
76 data_access = SP_MEMORY_ATTRIBUTES_ACCESS_RO;
77 }
78 }
79
80 smc_attr |= (data_access & SP_MEMORY_ATTRIBUTES_ACCESS_MASK)
81 << SP_MEMORY_ATTRIBUTES_ACCESS_SHIFT;
82
83 if ((attr & MT_EXECUTE_NEVER) != 0U) {
84 smc_attr |= SP_MEMORY_ATTRIBUTES_NON_EXEC;
85 }
86
87 return smc_attr;
88 }
89
spm_memory_attributes_get_smc_handler(sp_context_t * sp_ctx,uintptr_t base_va)90 int32_t spm_memory_attributes_get_smc_handler(sp_context_t *sp_ctx,
91 uintptr_t base_va)
92 {
93 uint32_t attributes;
94
95 spin_lock(&mem_attr_smc_lock);
96
97 int rc = xlat_get_mem_attributes_ctx(sp_ctx->xlat_ctx_handle,
98 base_va, &attributes);
99
100 spin_unlock(&mem_attr_smc_lock);
101
102 /* Convert error codes of xlat_get_mem_attributes_ctx() into SPM. */
103 assert((rc == 0) || (rc == -EINVAL));
104
105 if (rc == 0) {
106 return (int32_t) smc_mmap_to_smc_attr(attributes);
107 } else {
108 return SPM_INVALID_PARAMETER;
109 }
110 }
111
spm_memory_attributes_set_smc_handler(sp_context_t * sp_ctx,u_register_t page_address,u_register_t pages_count,u_register_t smc_attributes)112 int spm_memory_attributes_set_smc_handler(sp_context_t *sp_ctx,
113 u_register_t page_address,
114 u_register_t pages_count,
115 u_register_t smc_attributes)
116 {
117 uintptr_t base_va = (uintptr_t) page_address;
118 size_t size = (size_t) (pages_count * PAGE_SIZE);
119 uint32_t attributes = (uint32_t) smc_attributes;
120
121 INFO(" Start address : 0x%lx\n", base_va);
122 INFO(" Number of pages: %i (%zi bytes)\n", (int) pages_count, size);
123 INFO(" Attributes : 0x%x\n", attributes);
124
125 spin_lock(&mem_attr_smc_lock);
126
127 int ret = xlat_change_mem_attributes_ctx(sp_ctx->xlat_ctx_handle,
128 base_va, size,
129 smc_attr_to_mmap_attr(attributes));
130
131 spin_unlock(&mem_attr_smc_lock);
132
133 /* Convert error codes of xlat_change_mem_attributes_ctx() into SPM. */
134 assert((ret == 0) || (ret == -EINVAL));
135
136 return (ret == 0) ? SPM_SUCCESS : SPM_INVALID_PARAMETER;
137 }
138