1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
|
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (c) 2010,2015,2019 The Linux Foundation. All rights reserved.
* Copyright (C) 2015 Linaro Ltd.
*/
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/firmware/qcom/qcom_scm.h>
#include <linux/arm-smccc.h>
#include <linux/dma-mapping.h>
#include "qcom_scm.h"
static DEFINE_MUTEX(qcom_scm_lock);
/**
* struct arm_smccc_args
* @args: The array of values used in registers in smc instruction
*/
struct arm_smccc_args {
unsigned long args[8];
};
/**
* struct scm_legacy_command - one SCM command buffer
* @len: total available memory for command and response
* @buf_offset: start of command buffer
* @resp_hdr_offset: start of response buffer
* @id: command to be executed
* @buf: buffer returned from scm_legacy_get_command_buffer()
*
* An SCM command is laid out in memory as follows:
*
* ------------------- <--- struct scm_legacy_command
* | command header |
* ------------------- <--- scm_legacy_get_command_buffer()
* | command buffer |
* ------------------- <--- struct scm_legacy_response and
* | response header | scm_legacy_command_to_response()
* ------------------- <--- scm_legacy_get_response_buffer()
* | response buffer |
* -------------------
*
* There can be arbitrary padding between the headers and buffers so
* you should always use the appropriate scm_legacy_get_*_buffer() routines
* to access the buffers in a safe manner.
*/
struct scm_legacy_command {
__le32 len;
__le32 buf_offset;
__le32 resp_hdr_offset;
__le32 id;
__le32 buf[];
};
/**
* struct scm_legacy_response - one SCM response buffer
* @len: total available memory for response
* @buf_offset: start of response data relative to start of scm_legacy_response
* @is_complete: indicates if the command has finished processing
*/
struct scm_legacy_response {
__le32 len;
__le32 buf_offset;
__le32 is_complete;
};
/**
* scm_legacy_command_to_response() - Get a pointer to a scm_legacy_response
* @cmd: command
*
* Returns a pointer to a response for a command.
*/
static inline struct scm_legacy_response *scm_legacy_command_to_response(
const struct scm_legacy_command *cmd)
{
return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset);
}
/**
* scm_legacy_get_command_buffer() - Get a pointer to a command buffer
* @cmd: command
*
* Returns a pointer to the command buffer of a command.
*/
static inline void *scm_legacy_get_command_buffer(
const struct scm_legacy_command *cmd)
{
return (void *)cmd->buf;
}
/**
* scm_legacy_get_response_buffer() - Get a pointer to a response buffer
* @rsp: response
*
* Returns a pointer to a response buffer of a response.
*/
static inline void *scm_legacy_get_response_buffer(
const struct scm_legacy_response *rsp)
{
return (void *)rsp + le32_to_cpu(rsp->buf_offset);
}
static void __scm_legacy_do(const struct arm_smccc_args *smc,
struct arm_smccc_res *res)
{
do {
arm_smccc_smc(smc->args[0], smc->args[1], smc->args[2],
smc->args[3], smc->args[4], smc->args[5],
smc->args[6], smc->args[7], res);
} while (res->a0 == QCOM_SCM_INTERRUPTED);
}
/**
* scm_legacy_call() - Sends a command to the SCM and waits for the command to
* finish processing.
* @dev: device
* @desc: descriptor structure containing arguments and return values
* @res: results from SMC call
*
* A note on cache maintenance:
* Note that any buffers that are expected to be accessed by the secure world
* must be flushed before invoking qcom_scm_call and invalidated in the cache
* immediately after qcom_scm_call returns. Cache maintenance on the command
* and response buffers is taken care of by qcom_scm_call; however, callers are
* responsible for any other cached buffers passed over to the secure world.
*/
int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc,
struct qcom_scm_res *res)
{
u8 arglen = desc->arginfo & 0xf;
int ret = 0, context_id;
unsigned int i;
struct scm_legacy_command *cmd;
struct scm_legacy_response *rsp;
struct arm_smccc_args smc = {0};
struct arm_smccc_res smc_res;
const size_t cmd_len = arglen * sizeof(__le32);
const size_t resp_len = MAX_QCOM_SCM_RETS * sizeof(__le32);
size_t alloc_len = sizeof(*cmd) + cmd_len + sizeof(*rsp) + resp_len;
dma_addr_t cmd_phys;
__le32 *arg_buf;
const __le32 *res_buf;
cmd = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL);
if (!cmd)
return -ENOMEM;
cmd->len = cpu_to_le32(alloc_len);
cmd->buf_offset = cpu_to_le32(sizeof(*cmd));
cmd->resp_hdr_offset = cpu_to_le32(sizeof(*cmd) + cmd_len);
cmd->id = cpu_to_le32(SCM_LEGACY_FNID(desc->svc, desc->cmd));
arg_buf = scm_legacy_get_command_buffer(cmd);
for (i = 0; i < arglen; i++)
arg_buf[i] = cpu_to_le32(desc->args[i]);
rsp = scm_legacy_command_to_response(cmd);
cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE);
if (dma_mapping_error(dev, cmd_phys)) {
kfree(cmd);
return -ENOMEM;
}
smc.args[0] = 1;
smc.args[1] = (unsigned long)&context_id;
smc.args[2] = cmd_phys;
mutex_lock(&qcom_scm_lock);
__scm_legacy_do(&smc, &smc_res);
if (smc_res.a0)
ret = qcom_scm_remap_error(smc_res.a0);
mutex_unlock(&qcom_scm_lock);
if (ret)
goto out;
do {
dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len,
sizeof(*rsp), DMA_FROM_DEVICE);
} while (!rsp->is_complete);
dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len +
le32_to_cpu(rsp->buf_offset),
resp_len, DMA_FROM_DEVICE);
if (res) {
res_buf = scm_legacy_get_response_buffer(rsp);
for (i = 0; i < MAX_QCOM_SCM_RETS; i++)
res->result[i] = le32_to_cpu(res_buf[i]);
}
out:
dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE);
kfree(cmd);
return ret;
}
#define SCM_LEGACY_ATOMIC_N_REG_ARGS 5
#define SCM_LEGACY_ATOMIC_FIRST_REG_IDX 2
#define SCM_LEGACY_CLASS_REGISTER (0x2 << 8)
#define SCM_LEGACY_MASK_IRQS BIT(5)
#define SCM_LEGACY_ATOMIC_ID(svc, cmd, n) \
((SCM_LEGACY_FNID(svc, cmd) << 12) | \
SCM_LEGACY_CLASS_REGISTER | \
SCM_LEGACY_MASK_IRQS | \
(n & 0xf))
/**
* scm_legacy_call_atomic() - Send an atomic SCM command with up to 5 arguments
* and 3 return values
* @unused: device, legacy argument, not used, can be NULL
* @desc: SCM call descriptor containing arguments
* @res: SCM call return values
*
* This shall only be used with commands that are guaranteed to be
* uninterruptable, atomic and SMP safe.
*/
int scm_legacy_call_atomic(struct device *unused,
const struct qcom_scm_desc *desc,
struct qcom_scm_res *res)
{
int context_id;
struct arm_smccc_res smc_res;
size_t arglen = desc->arginfo & 0xf;
BUG_ON(arglen > SCM_LEGACY_ATOMIC_N_REG_ARGS);
arm_smccc_smc(SCM_LEGACY_ATOMIC_ID(desc->svc, desc->cmd, arglen),
(unsigned long)&context_id,
desc->args[0], desc->args[1], desc->args[2],
desc->args[3], desc->args[4], 0, &smc_res);
if (res) {
res->result[0] = smc_res.a1;
res->result[1] = smc_res.a2;
res->result[2] = smc_res.a3;
}
return smc_res.a0;
}
|
