1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
4 */
5
6 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
7
8 #include <linux/firmware/qcom/qcom_tzmem.h>
9 #include <linux/mm.h>
10
11 #include "qcomtee.h"
12
13 /**
14 * define MAX_OUTBOUND_BUFFER_SIZE - Maximum size of outbound buffers.
15 *
16 * The size of outbound buffer depends on QTEE callback requests.
17 */
18 #define MAX_OUTBOUND_BUFFER_SIZE SZ_4K
19
20 /**
21 * define MAX_INBOUND_BUFFER_SIZE - Maximum size of the inbound buffer.
22 *
23 * The size of the inbound buffer depends on the user's requests,
24 * specifically the number of IB and OB arguments. If an invocation
25 * requires a size larger than %MAX_INBOUND_BUFFER_SIZE, the user should
26 * consider using another form of shared memory with QTEE.
27 */
28 #define MAX_INBOUND_BUFFER_SIZE SZ_4M
29
30 /**
31 * qcomtee_msg_buffers_alloc() - Allocate inbound and outbound buffers.
32 * @oic: context to use for the current invocation.
33 * @u: array of arguments for the current invocation.
34 *
35 * It calculates the size of inbound and outbound buffers based on the
36 * arguments in @u. It allocates the buffers from the teedev pool.
37 *
38 * Return: On success, returns 0. On error, returns < 0.
39 */
qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx * oic,struct qcomtee_arg * u)40 int qcomtee_msg_buffers_alloc(struct qcomtee_object_invoke_ctx *oic,
41 struct qcomtee_arg *u)
42 {
43 struct tee_context *ctx = oic->ctx;
44 struct tee_shm *shm;
45 size_t size;
46 int i;
47
48 /* Start offset in a message for buffer arguments. */
49 size = qcomtee_msg_buffer_args(struct qcomtee_msg_object_invoke,
50 qcomtee_args_len(u));
51 if (size > MAX_INBOUND_BUFFER_SIZE)
52 return -EINVAL;
53
54 /* Add size of IB arguments. */
55 qcomtee_arg_for_each_input_buffer(i, u) {
56 size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
57 if (size > MAX_INBOUND_BUFFER_SIZE)
58 return -EINVAL;
59 }
60
61 /* Add size of OB arguments. */
62 qcomtee_arg_for_each_output_buffer(i, u) {
63 size = size_add(size, qcomtee_msg_offset_align(u[i].b.size));
64 if (size > MAX_INBOUND_BUFFER_SIZE)
65 return -EINVAL;
66 }
67
68 shm = tee_shm_alloc_priv_buf(ctx, size);
69 if (IS_ERR(shm))
70 return PTR_ERR(shm);
71
72 /* Allocate inbound buffer. */
73 oic->in_shm = shm;
74 shm = tee_shm_alloc_priv_buf(ctx, MAX_OUTBOUND_BUFFER_SIZE);
75 if (IS_ERR(shm)) {
76 tee_shm_free(oic->in_shm);
77
78 return PTR_ERR(shm);
79 }
80 /* Allocate outbound buffer. */
81 oic->out_shm = shm;
82
83 oic->in_msg.addr = tee_shm_get_va(oic->in_shm, 0);
84 oic->in_msg.size = tee_shm_get_size(oic->in_shm);
85 oic->out_msg.addr = tee_shm_get_va(oic->out_shm, 0);
86 oic->out_msg.size = tee_shm_get_size(oic->out_shm);
87 /* QTEE assume unused buffers are zeroed. */
88 memzero_explicit(oic->in_msg.addr, oic->in_msg.size);
89 memzero_explicit(oic->out_msg.addr, oic->out_msg.size);
90
91 return 0;
92 }
93
qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx * oic)94 void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic)
95 {
96 tee_shm_free(oic->in_shm);
97 tee_shm_free(oic->out_shm);
98 }
99
100 /* Dynamic shared memory pool based on tee_dyn_shm_alloc_helper(). */
101
qcomtee_shm_register(struct tee_context * ctx,struct tee_shm * shm,struct page ** pages,size_t num_pages,unsigned long start)102 static int qcomtee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
103 struct page **pages, size_t num_pages,
104 unsigned long start)
105 {
106 return qcom_tzmem_shm_bridge_create(shm->paddr, shm->size,
107 &shm->sec_world_id);
108 }
109
qcomtee_shm_unregister(struct tee_context * ctx,struct tee_shm * shm)110 static int qcomtee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
111 {
112 qcom_tzmem_shm_bridge_delete(shm->sec_world_id);
113
114 return 0;
115 }
116
pool_op_alloc(struct tee_shm_pool * pool,struct tee_shm * shm,size_t size,size_t align)117 static int pool_op_alloc(struct tee_shm_pool *pool, struct tee_shm *shm,
118 size_t size, size_t align)
119 {
120 return tee_dyn_shm_alloc_helper(shm, size, align, qcomtee_shm_register);
121 }
122
pool_op_free(struct tee_shm_pool * pool,struct tee_shm * shm)123 static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
124 {
125 tee_dyn_shm_free_helper(shm, qcomtee_shm_unregister);
126 }
127
pool_op_destroy_pool(struct tee_shm_pool * pool)128 static void pool_op_destroy_pool(struct tee_shm_pool *pool)
129 {
130 kfree(pool);
131 }
132
133 static const struct tee_shm_pool_ops pool_ops = {
134 .alloc = pool_op_alloc,
135 .free = pool_op_free,
136 .destroy_pool = pool_op_destroy_pool,
137 };
138
qcomtee_shm_pool_alloc(void)139 struct tee_shm_pool *qcomtee_shm_pool_alloc(void)
140 {
141 struct tee_shm_pool *pool;
142
143 pool = kzalloc_obj(*pool);
144 if (!pool)
145 return ERR_PTR(-ENOMEM);
146
147 pool->ops = &pool_ops;
148
149 return pool;
150 }
151