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08dbd0f8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
e0aa1539 | 2 | /* Copyright (c) 2010,2015,2019 The Linux Foundation. All rights reserved. |
b6a1dfbc | 3 | * Copyright (C) 2015 Linaro Ltd. |
b6a1dfbc KG |
4 | */ |
5 | ||
6 | #include <linux/slab.h> | |
7 | #include <linux/io.h> | |
8 | #include <linux/module.h> | |
9 | #include <linux/mutex.h> | |
10 | #include <linux/errno.h> | |
11 | #include <linux/err.h> | |
12 | #include <linux/qcom_scm.h> | |
02248981 | 13 | #include <linux/arm-smccc.h> |
16e59467 | 14 | #include <linux/dma-mapping.h> |
b6a1dfbc KG |
15 | |
16 | #include "qcom_scm.h" | |
17 | ||
b6a1dfbc KG |
18 | static DEFINE_MUTEX(qcom_scm_lock); |
19 | ||
efd2b15c | 20 | |
590e9280 EB |
21 | /** |
22 | * struct arm_smccc_args | |
23 | * @args: The array of values used in registers in smc instruction | |
24 | */ | |
25 | struct arm_smccc_args { | |
26 | unsigned long args[8]; | |
27 | }; | |
28 | ||
fd62c30b | 29 | |
b6a1dfbc | 30 | /** |
e0aa1539 | 31 | * struct scm_legacy_command - one SCM command buffer |
b6a1dfbc KG |
32 | * @len: total available memory for command and response |
33 | * @buf_offset: start of command buffer | |
34 | * @resp_hdr_offset: start of response buffer | |
35 | * @id: command to be executed | |
e0aa1539 | 36 | * @buf: buffer returned from scm_legacy_get_command_buffer() |
b6a1dfbc KG |
37 | * |
38 | * An SCM command is laid out in memory as follows: | |
39 | * | |
e0aa1539 | 40 | * ------------------- <--- struct scm_legacy_command |
b6a1dfbc | 41 | * | command header | |
e0aa1539 | 42 | * ------------------- <--- scm_legacy_get_command_buffer() |
b6a1dfbc | 43 | * | command buffer | |
e0aa1539 EB |
44 | * ------------------- <--- struct scm_legacy_response and |
45 | * | response header | scm_legacy_command_to_response() | |
46 | * ------------------- <--- scm_legacy_get_response_buffer() | |
b6a1dfbc KG |
47 | * | response buffer | |
48 | * ------------------- | |
49 | * | |
50 | * There can be arbitrary padding between the headers and buffers so | |
e0aa1539 | 51 | * you should always use the appropriate scm_legacy_get_*_buffer() routines |
b6a1dfbc KG |
52 | * to access the buffers in a safe manner. |
53 | */ | |
e0aa1539 | 54 | struct scm_legacy_command { |
b6a1dfbc KG |
55 | __le32 len; |
56 | __le32 buf_offset; | |
57 | __le32 resp_hdr_offset; | |
58 | __le32 id; | |
c2097772 | 59 | __le32 buf[]; |
b6a1dfbc KG |
60 | }; |
61 | ||
62 | /** | |
e0aa1539 | 63 | * struct scm_legacy_response - one SCM response buffer |
b6a1dfbc | 64 | * @len: total available memory for response |
e0aa1539 | 65 | * @buf_offset: start of response data relative to start of scm_legacy_response |
b6a1dfbc KG |
66 | * @is_complete: indicates if the command has finished processing |
67 | */ | |
e0aa1539 | 68 | struct scm_legacy_response { |
b6a1dfbc KG |
69 | __le32 len; |
70 | __le32 buf_offset; | |
71 | __le32 is_complete; | |
72 | }; | |
73 | ||
b6a1dfbc | 74 | /** |
e0aa1539 | 75 | * scm_legacy_command_to_response() - Get a pointer to a scm_legacy_response |
b6a1dfbc KG |
76 | * @cmd: command |
77 | * | |
78 | * Returns a pointer to a response for a command. | |
79 | */ | |
e0aa1539 EB |
80 | static inline struct scm_legacy_response *scm_legacy_command_to_response( |
81 | const struct scm_legacy_command *cmd) | |
b6a1dfbc KG |
82 | { |
83 | return (void *)cmd + le32_to_cpu(cmd->resp_hdr_offset); | |
84 | } | |
85 | ||
86 | /** | |
e0aa1539 | 87 | * scm_legacy_get_command_buffer() - Get a pointer to a command buffer |
b6a1dfbc KG |
88 | * @cmd: command |
89 | * | |
90 | * Returns a pointer to the command buffer of a command. | |
91 | */ | |
e0aa1539 EB |
92 | static inline void *scm_legacy_get_command_buffer( |
93 | const struct scm_legacy_command *cmd) | |
b6a1dfbc KG |
94 | { |
95 | return (void *)cmd->buf; | |
96 | } | |
97 | ||
98 | /** | |
e0aa1539 | 99 | * scm_legacy_get_response_buffer() - Get a pointer to a response buffer |
b6a1dfbc KG |
100 | * @rsp: response |
101 | * | |
102 | * Returns a pointer to a response buffer of a response. | |
103 | */ | |
e0aa1539 EB |
104 | static inline void *scm_legacy_get_response_buffer( |
105 | const struct scm_legacy_response *rsp) | |
b6a1dfbc KG |
106 | { |
107 | return (void *)rsp + le32_to_cpu(rsp->buf_offset); | |
108 | } | |
109 | ||
590e9280 EB |
110 | static void __scm_legacy_do(const struct arm_smccc_args *smc, |
111 | struct arm_smccc_res *res) | |
b6a1dfbc | 112 | { |
b6a1dfbc | 113 | do { |
590e9280 EB |
114 | arm_smccc_smc(smc->args[0], smc->args[1], smc->args[2], |
115 | smc->args[3], smc->args[4], smc->args[5], | |
116 | smc->args[6], smc->args[7], res); | |
117 | } while (res->a0 == QCOM_SCM_INTERRUPTED); | |
b6a1dfbc KG |
118 | } |
119 | ||
b6a1dfbc | 120 | /** |
efd2b15c EB |
121 | * qcom_scm_call() - Sends a command to the SCM and waits for the command to |
122 | * finish processing. | |
b6a1dfbc KG |
123 | * |
124 | * A note on cache maintenance: | |
125 | * Note that any buffers that are expected to be accessed by the secure world | |
126 | * must be flushed before invoking qcom_scm_call and invalidated in the cache | |
127 | * immediately after qcom_scm_call returns. Cache maintenance on the command | |
128 | * and response buffers is taken care of by qcom_scm_call; however, callers are | |
129 | * responsible for any other cached buffers passed over to the secure world. | |
130 | */ | |
9a434cee EB |
131 | int scm_legacy_call(struct device *dev, const struct qcom_scm_desc *desc, |
132 | struct qcom_scm_res *res) | |
b6a1dfbc | 133 | { |
efd2b15c | 134 | u8 arglen = desc->arginfo & 0xf; |
590e9280 | 135 | int ret = 0, context_id; |
efd2b15c | 136 | unsigned int i; |
e0aa1539 EB |
137 | struct scm_legacy_command *cmd; |
138 | struct scm_legacy_response *rsp; | |
590e9280 EB |
139 | struct arm_smccc_args smc = {0}; |
140 | struct arm_smccc_res smc_res; | |
efd2b15c EB |
141 | const size_t cmd_len = arglen * sizeof(__le32); |
142 | const size_t resp_len = MAX_QCOM_SCM_RETS * sizeof(__le32); | |
16e59467 AG |
143 | size_t alloc_len = sizeof(*cmd) + cmd_len + sizeof(*rsp) + resp_len; |
144 | dma_addr_t cmd_phys; | |
efd2b15c EB |
145 | __le32 *arg_buf; |
146 | const __le32 *res_buf; | |
b6a1dfbc | 147 | |
16e59467 | 148 | cmd = kzalloc(PAGE_ALIGN(alloc_len), GFP_KERNEL); |
b6a1dfbc KG |
149 | if (!cmd) |
150 | return -ENOMEM; | |
151 | ||
16e59467 AG |
152 | cmd->len = cpu_to_le32(alloc_len); |
153 | cmd->buf_offset = cpu_to_le32(sizeof(*cmd)); | |
154 | cmd->resp_hdr_offset = cpu_to_le32(sizeof(*cmd) + cmd_len); | |
efd2b15c | 155 | cmd->id = cpu_to_le32(SCM_LEGACY_FNID(desc->svc, desc->cmd)); |
16e59467 | 156 | |
efd2b15c EB |
157 | arg_buf = scm_legacy_get_command_buffer(cmd); |
158 | for (i = 0; i < arglen; i++) | |
159 | arg_buf[i] = cpu_to_le32(desc->args[i]); | |
b6a1dfbc | 160 | |
e0aa1539 | 161 | rsp = scm_legacy_command_to_response(cmd); |
16e59467 AG |
162 | |
163 | cmd_phys = dma_map_single(dev, cmd, alloc_len, DMA_TO_DEVICE); | |
164 | if (dma_mapping_error(dev, cmd_phys)) { | |
165 | kfree(cmd); | |
166 | return -ENOMEM; | |
167 | } | |
168 | ||
590e9280 EB |
169 | smc.args[0] = 1; |
170 | smc.args[1] = (unsigned long)&context_id; | |
171 | smc.args[2] = cmd_phys; | |
172 | ||
b6a1dfbc | 173 | mutex_lock(&qcom_scm_lock); |
590e9280 EB |
174 | __scm_legacy_do(&smc, &smc_res); |
175 | if (smc_res.a0) | |
176 | ret = qcom_scm_remap_error(smc_res.a0); | |
b6a1dfbc KG |
177 | mutex_unlock(&qcom_scm_lock); |
178 | if (ret) | |
179 | goto out; | |
180 | ||
b6a1dfbc | 181 | do { |
16e59467 AG |
182 | dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len, |
183 | sizeof(*rsp), DMA_FROM_DEVICE); | |
b6a1dfbc KG |
184 | } while (!rsp->is_complete); |
185 | ||
efd2b15c EB |
186 | dma_sync_single_for_cpu(dev, cmd_phys + sizeof(*cmd) + cmd_len + |
187 | le32_to_cpu(rsp->buf_offset), | |
188 | resp_len, DMA_FROM_DEVICE); | |
189 | ||
190 | if (res) { | |
191 | res_buf = scm_legacy_get_response_buffer(rsp); | |
192 | for (i = 0; i < MAX_QCOM_SCM_RETS; i++) | |
193 | res->result[i] = le32_to_cpu(res_buf[i]); | |
16e59467 | 194 | } |
b6a1dfbc | 195 | out: |
16e59467 AG |
196 | dma_unmap_single(dev, cmd_phys, alloc_len, DMA_TO_DEVICE); |
197 | kfree(cmd); | |
b6a1dfbc KG |
198 | return ret; |
199 | } | |
200 | ||
84528486 EB |
201 | #define SCM_LEGACY_ATOMIC_N_REG_ARGS 5 |
202 | #define SCM_LEGACY_ATOMIC_FIRST_REG_IDX 2 | |
e0aa1539 EB |
203 | #define SCM_LEGACY_CLASS_REGISTER (0x2 << 8) |
204 | #define SCM_LEGACY_MASK_IRQS BIT(5) | |
205 | #define SCM_LEGACY_ATOMIC_ID(svc, cmd, n) \ | |
fd62c30b | 206 | ((SCM_LEGACY_FNID(svc, cmd) << 12) | \ |
e0aa1539 EB |
207 | SCM_LEGACY_CLASS_REGISTER | \ |
208 | SCM_LEGACY_MASK_IRQS | \ | |
b6a1dfbc KG |
209 | (n & 0xf)) |
210 | ||
211 | /** | |
84528486 EB |
212 | * qcom_scm_call_atomic() - Send an atomic SCM command with up to 5 arguments |
213 | * and 3 return values | |
214 | * @desc: SCM call descriptor containing arguments | |
215 | * @res: SCM call return values | |
b6a1dfbc KG |
216 | * |
217 | * This shall only be used with commands that are guaranteed to be | |
218 | * uninterruptable, atomic and SMP safe. | |
219 | */ | |
9a434cee EB |
220 | int scm_legacy_call_atomic(struct device *unused, |
221 | const struct qcom_scm_desc *desc, | |
222 | struct qcom_scm_res *res) | |
b6a1dfbc KG |
223 | { |
224 | int context_id; | |
84528486 EB |
225 | struct arm_smccc_res smc_res; |
226 | size_t arglen = desc->arginfo & 0xf; | |
02248981 | 227 | |
84528486 | 228 | BUG_ON(arglen > SCM_LEGACY_ATOMIC_N_REG_ARGS); |
b6a1dfbc | 229 | |
84528486 EB |
230 | arm_smccc_smc(SCM_LEGACY_ATOMIC_ID(desc->svc, desc->cmd, arglen), |
231 | (unsigned long)&context_id, | |
232 | desc->args[0], desc->args[1], desc->args[2], | |
233 | desc->args[3], desc->args[4], 0, &smc_res); | |
b6a1dfbc | 234 | |
84528486 EB |
235 | if (res) { |
236 | res->result[0] = smc_res.a1; | |
237 | res->result[1] = smc_res.a2; | |
238 | res->result[2] = smc_res.a3; | |
239 | } | |
13e77747 | 240 | |
84528486 | 241 | return smc_res.a0; |
13e77747 | 242 | } |