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 */
40int 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(addend1: 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(addend1: 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(ptr: shm))
70 return PTR_ERR(ptr: 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(ptr: shm)) {
76 tee_shm_free(shm: oic->in_shm);
77
78 return PTR_ERR(ptr: shm);
79 }
80 /* Allocate outbound buffer. */
81 oic->out_shm = shm;
82
83 oic->in_msg.addr = tee_shm_get_va(shm: oic->in_shm, offs: 0);
84 oic->in_msg.size = tee_shm_get_size(shm: oic->in_shm);
85 oic->out_msg.addr = tee_shm_get_va(shm: oic->out_shm, offs: 0);
86 oic->out_msg.size = tee_shm_get_size(shm: oic->out_shm);
87 /* QTEE assume unused buffers are zeroed. */
88 memzero_explicit(s: oic->in_msg.addr, count: oic->in_msg.size);
89 memzero_explicit(s: oic->out_msg.addr, count: oic->out_msg.size);
90
91 return 0;
92}
93
94void qcomtee_msg_buffers_free(struct qcomtee_object_invoke_ctx *oic)
95{
96 tee_shm_free(shm: oic->in_shm);
97 tee_shm_free(shm: oic->out_shm);
98}
99
100/* Dynamic shared memory pool based on tee_dyn_shm_alloc_helper(). */
101
102static 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(paddr: shm->paddr, size: shm->size,
107 handle: &shm->sec_world_id);
108}
109
110static int qcomtee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
111{
112 qcom_tzmem_shm_bridge_delete(handle: shm->sec_world_id);
113
114 return 0;
115}
116
117static 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, shm_register: qcomtee_shm_register);
121}
122
123static void pool_op_free(struct tee_shm_pool *pool, struct tee_shm *shm)
124{
125 tee_dyn_shm_free_helper(shm, shm_unregister: qcomtee_shm_unregister);
126}
127
128static void pool_op_destroy_pool(struct tee_shm_pool *pool)
129{
130 kfree(objp: pool);
131}
132
133static 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
139struct tee_shm_pool *qcomtee_shm_pool_alloc(void)
140{
141 struct tee_shm_pool *pool;
142
143 pool = kzalloc(sizeof(*pool), GFP_KERNEL);
144 if (!pool)
145 return ERR_PTR(error: -ENOMEM);
146
147 pool->ops = &pool_ops;
148
149 return pool;
150}
151

source code of linux/drivers/tee/qcomtee/shm.c