xref: /optee_os/core/drivers/stm32_tamp.c (revision 19a31ec40245ae01a9adcd206eec2a4bb4479fc9)
1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * Copyright (c) 2021-2022, STMicroelectronics
4  */
5 
6 #include <drivers/clk.h>
7 #include <drivers/clk_dt.h>
8 #include <drivers/stm32_tamp.h>
9 #include <io.h>
10 #include <kernel/dt.h>
11 #include <kernel/dt_driver.h>
12 #include <kernel/interrupt.h>
13 #include <libfdt.h>
14 #include <mm/core_memprot.h>
15 #include <stdbool.h>
16 
17 /* STM32 Registers */
18 #define _TAMP_CR1			0x00U
19 #define _TAMP_CR2			0x04U
20 #define _TAMP_CR3			0x08U
21 #define _TAMP_FLTCR			0x0CU
22 #define _TAMP_ATCR1			0x10U
23 #define _TAMP_ATSEEDR			0x14U
24 #define _TAMP_ATOR			0x18U
25 #define _TAMP_ATCR2			0x1CU
26 #define _TAMP_SECCFGR			0x20U
27 #define _TAMP_SMCR			0x20U
28 #define _TAMP_PRIVCFGR			0x24U
29 #define _TAMP_IER			0x2CU
30 #define _TAMP_SR			0x30U
31 #define _TAMP_MISR			0x34U
32 #define _TAMP_SMISR			0x38U
33 #define _TAMP_SCR			0x3CU
34 #define _TAMP_COUNTR			0x40U
35 #define _TAMP_COUNT2R			0x44U
36 #define _TAMP_OR			0x50U
37 #define _TAMP_ERCFGR			0X54U
38 #define _TAMP_HWCFGR2			0x3ECU
39 #define _TAMP_HWCFGR1			0x3F0U
40 #define _TAMP_VERR			0x3F4U
41 #define _TAMP_IPIDR			0x3F8U
42 #define _TAMP_SIDR			0x3FCU
43 
44 /* _TAMP_SECCFGR bit fields */
45 #define _TAMP_SECCFGR_BKPRWSEC_MASK	GENMASK_32(7, 0)
46 #define _TAMP_SECCFGR_BKPRWSEC_SHIFT	0U
47 #define _TAMP_SECCFGR_CNT2SEC		BIT(14)
48 #define _TAMP_SECCFGR_CNT1SEC		BIT(15)
49 #define _TAMP_SECCFGR_BKPWSEC_MASK	GENMASK_32(23, 16)
50 #define _TAMP_SECCFGR_BKPWSEC_SHIFT	16U
51 #define _TAMP_SECCFGR_BHKLOCK		BIT(30)
52 #define _TAMP_SECCFGR_TAMPSEC		BIT(31)
53 #define _TAMP_SECCFGR_BUT_BKP_MASK	(GENMASK_32(31, 30) | \
54 					 GENMASK_32(15, 14))
55 
56 /* _TAMP_SMCR bit fields */
57 #define _TAMP_SMCR_BKPRWDPROT_MASK	GENMASK_32(7, 0)
58 #define _TAMP_SMCR_BKPRWDPROT_SHIFT	0U
59 #define _TAMP_SMCR_BKPWDPROT_MASK	GENMASK_32(23, 16)
60 #define _TAMP_SMCR_BKPWDPROT_SHIFT	16U
61 #define _TAMP_SMCR_DPROT		BIT(31)
62 /*
63  * _TAMP_PRIVCFGR bit fields
64  */
65 #define _TAMP_PRIVCFG_CNT2PRIV		BIT(14)
66 #define _TAMP_PRIVCFG_CNT1PRIV		BIT(15)
67 #define _TAMP_PRIVCFG_BKPRWPRIV		BIT(29)
68 #define _TAMP_PRIVCFG_BKPWPRIV		BIT(30)
69 #define _TAMP_PRIVCFG_TAMPPRIV		BIT(31)
70 #define _TAMP_PRIVCFGR_MASK		(GENMASK_32(31, 29) | \
71 					 GENMASK_32(15, 14))
72 
73 /*
74  * _TAMP_PRIVCFGR bit fields
75  */
76 #define _TAMP_PRIVCFG_CNT2PRIV		BIT(14)
77 #define _TAMP_PRIVCFG_CNT1PRIV		BIT(15)
78 #define _TAMP_PRIVCFG_BKPRWPRIV		BIT(29)
79 #define _TAMP_PRIVCFG_BKPWPRIV		BIT(30)
80 #define _TAMP_PRIVCFG_TAMPPRIV		BIT(31)
81 #define _TAMP_PRIVCFGR_MASK		(GENMASK_32(31, 29) | \
82 					 GENMASK_32(15, 14))
83 
84 /* _TAMP_HWCFGR2 bit fields */
85 #define _TAMP_HWCFGR2_TZ		GENMASK_32(11, 8)
86 #define _TAMP_HWCFGR2_OR		GENMASK_32(7, 0)
87 
88 /* _TAMP_HWCFGR1 bit fields */
89 #define _TAMP_HWCFGR1_BKPREG		GENMASK_32(7, 0)
90 #define _TAMP_HWCFGR1_TAMPER		GENMASK_32(11, 8)
91 #define _TAMP_HWCFGR1_ACTIVE		GENMASK_32(15, 12)
92 #define _TAMP_HWCFGR1_INTERN		GENMASK_32(31, 16)
93 #define _TAMP_HWCFGR1_ITAMP_MAX_ID	16U
94 #define _TAMP_HWCFGR1_ITAMP(id)		BIT((id) - INT_TAMP1 + 16U)
95 
96 /* _TAMP_VERR bit fields */
97 #define _TAMP_VERR_MINREV		GENMASK_32(3, 0)
98 #define _TAMP_VERR_MAJREV		GENMASK_32(7, 4)
99 
100 /*
101  * TAMP instance data
102  * @base - IOMEM base address
103  * @clock - TAMP clock
104  * @it - TAMP interrupt number
105  * @hwconf1 - Copy of TAMP HWCONF1 register content
106  * @hwconf2 - Copy of TAMP HWCONF2 register content
107  * @compat - Reference to compat data passed at driver initialization
108  */
109 struct stm32_tamp_instance {
110 	struct io_pa_va base;
111 	struct clk *clock;
112 	int it;
113 	uint32_t hwconf1;
114 	uint32_t hwconf2;
115 	struct stm32_tamp_compat *compat;
116 };
117 
118 /*
119  * Compatibility capabilities
120  * TAMP_HAS_REGISTER_SECCFG - Supports SECCFGR, otherwise supports SMCR register
121  * TAMP_HAS_REGISTER_PRIVCFG - Supports PRIVCFGR configuration register
122  */
123 #define TAMP_HAS_REGISTER_SECCFG	BIT(0)
124 #define TAMP_HAS_REGISTER_PRIVCFGR	BIT(1)
125 
126 /*
127  * @nb_monotonic_counter - Number of monotic counter supported
128  * @tags - Bit flags TAMP_HAS_* for compatibily management
129  */
130 struct stm32_tamp_compat {
131 	int nb_monotonic_counter;
132 	uint32_t tags;
133 };
134 
135 /* Expects at most a single instance */
136 static struct stm32_tamp_instance *stm32_tamp_device;
137 
138 TEE_Result stm32_tamp_set_secure_bkpregs(struct stm32_bkpregs_conf *bkr_conf)
139 {
140 	struct stm32_tamp_instance *tamp = stm32_tamp_device;
141 	vaddr_t base = 0;
142 	uint32_t first_z2 = 0;
143 	uint32_t first_z3 = 0;
144 
145 	if (!tamp)
146 		return TEE_ERROR_DEFER_DRIVER_INIT;
147 
148 	if (!bkr_conf)
149 		return TEE_ERROR_BAD_PARAMETERS;
150 
151 	base = io_pa_or_va(&tamp->base, 1);
152 
153 	first_z2 = bkr_conf->nb_zone1_regs;
154 	first_z3 = bkr_conf->nb_zone1_regs + bkr_conf->nb_zone2_regs;
155 
156 	if ((first_z2 > (tamp->hwconf1 & _TAMP_HWCFGR1_BKPREG)) ||
157 	    (first_z3 > (tamp->hwconf1 & _TAMP_HWCFGR1_BKPREG)))
158 		return TEE_ERROR_BAD_PARAMETERS;
159 
160 	if (tamp->compat && (tamp->compat->tags & TAMP_HAS_REGISTER_SECCFG)) {
161 		io_clrsetbits32(base + _TAMP_SECCFGR,
162 				_TAMP_SECCFGR_BKPRWSEC_MASK,
163 				(first_z2 << _TAMP_SECCFGR_BKPRWSEC_SHIFT) &
164 				_TAMP_SECCFGR_BKPRWSEC_MASK);
165 
166 		io_clrsetbits32(base + _TAMP_SECCFGR,
167 				_TAMP_SECCFGR_BKPWSEC_MASK,
168 				(first_z3 << _TAMP_SECCFGR_BKPWSEC_SHIFT) &
169 				_TAMP_SECCFGR_BKPWSEC_MASK);
170 	} else {
171 		io_clrsetbits32(base + _TAMP_SMCR,
172 				_TAMP_SMCR_BKPRWDPROT_MASK,
173 				(first_z2 << _TAMP_SMCR_BKPRWDPROT_SHIFT) &
174 				_TAMP_SMCR_BKPRWDPROT_MASK);
175 
176 		io_clrsetbits32(base + _TAMP_SMCR,
177 				_TAMP_SMCR_BKPWDPROT_MASK,
178 				(first_z3 << _TAMP_SMCR_BKPWDPROT_SHIFT) &
179 				_TAMP_SMCR_BKPWDPROT_MASK);
180 	}
181 
182 	return TEE_SUCCESS;
183 }
184 
185 static void stm32_tamp_set_secure(struct stm32_tamp_instance *tamp,
186 				  uint32_t mode)
187 {
188 	vaddr_t base = io_pa_or_va(&tamp->base, 1);
189 
190 	if (tamp->compat && (tamp->compat->tags & TAMP_HAS_REGISTER_SECCFG)) {
191 		io_clrsetbits32(base + _TAMP_SECCFGR,
192 				_TAMP_SECCFGR_BUT_BKP_MASK,
193 				mode & _TAMP_SECCFGR_BUT_BKP_MASK);
194 	} else {
195 		/*
196 		 * Note: MP15 doesn't use SECCFG register and
197 		 * inverts the secure bit.
198 		 */
199 		if (mode & _TAMP_SECCFGR_TAMPSEC)
200 			io_clrbits32(base + _TAMP_SMCR, _TAMP_SMCR_DPROT);
201 		else
202 			io_setbits32(base + _TAMP_SMCR, _TAMP_SMCR_DPROT);
203 	}
204 }
205 
206 static void stm32_tamp_set_privilege(struct stm32_tamp_instance *tamp,
207 				     uint32_t mode)
208 {
209 	vaddr_t base = io_pa_or_va(&tamp->base, 1);
210 
211 	if (tamp->compat && (tamp->compat->tags & TAMP_HAS_REGISTER_PRIVCFGR))
212 		io_clrsetbits32(base + _TAMP_PRIVCFGR, _TAMP_PRIVCFGR_MASK,
213 				mode & _TAMP_PRIVCFGR_MASK);
214 }
215 
216 static TEE_Result stm32_tamp_parse_fdt(struct stm32_tamp_instance *tamp,
217 				       const void *fdt, int node,
218 				       const void *compat)
219 {
220 	struct dt_node_info dt_tamp = { };
221 
222 	fdt_fill_device_info(fdt, &dt_tamp, node);
223 
224 	if (dt_tamp.reg == DT_INFO_INVALID_REG ||
225 	    dt_tamp.reg_size == DT_INFO_INVALID_REG_SIZE)
226 		return TEE_ERROR_BAD_PARAMETERS;
227 
228 	tamp->compat = (struct stm32_tamp_compat *)compat;
229 	tamp->it = dt_tamp.interrupt;
230 	tamp->base.pa = dt_tamp.reg;
231 	io_pa_or_va_secure(&tamp->base, dt_tamp.reg_size);
232 
233 	return clk_dt_get_by_index(fdt, node, 0, &tamp->clock);
234 }
235 
236 static TEE_Result stm32_tamp_probe(const void *fdt, int node,
237 				   const void *compat_data)
238 {
239 	struct stm32_tamp_instance *tamp = NULL;
240 	uint32_t __maybe_unused revision = 0;
241 	TEE_Result res = TEE_SUCCESS;
242 	vaddr_t base = 0;
243 
244 	tamp = calloc(1, sizeof(*tamp));
245 	if (!tamp)
246 		return TEE_ERROR_OUT_OF_MEMORY;
247 
248 	res = stm32_tamp_parse_fdt(tamp, fdt, node, compat_data);
249 	if (res)
250 		goto err;
251 
252 	clk_enable(tamp->clock);
253 
254 	base = io_pa_or_va(&tamp->base, 1);
255 
256 	tamp->hwconf1 = io_read32(base + _TAMP_HWCFGR1);
257 	tamp->hwconf2 = io_read32(base + _TAMP_HWCFGR2);
258 
259 	revision = io_read32(base + _TAMP_VERR);
260 	FMSG("STM32 TAMPER V%"PRIx32".%"PRIu32,
261 	     (revision & _TAMP_VERR_MAJREV) >> 4, revision & _TAMP_VERR_MINREV);
262 
263 	if (!(tamp->hwconf2 & _TAMP_HWCFGR2_TZ)) {
264 		EMSG("TAMP doesn't support TrustZone");
265 		res = TEE_ERROR_NOT_SUPPORTED;
266 		goto err_clk;
267 	}
268 
269 	/*
270 	 * Enforce secure only access to protected TAMP registers.
271 	 * Allow non-secure access to monotonic counter.
272 	 */
273 	stm32_tamp_set_secure(tamp, _TAMP_SECCFGR_TAMPSEC);
274 
275 	/*
276 	 * Enforce privilege only access to TAMP registers, backup
277 	 * registers and monotonic counter.
278 	 */
279 	stm32_tamp_set_privilege(tamp, _TAMP_PRIVCFG_TAMPPRIV |
280 				 _TAMP_PRIVCFG_BKPRWPRIV |
281 				 _TAMP_PRIVCFG_BKPWPRIV);
282 
283 	stm32_tamp_device = tamp;
284 
285 	return TEE_SUCCESS;
286 
287 err_clk:
288 	clk_disable(tamp->clock);
289 err:
290 	free(tamp);
291 	return res;
292 }
293 
294 static const struct stm32_tamp_compat mp13_compat = {
295 	.nb_monotonic_counter = 2,
296 	.tags = TAMP_HAS_REGISTER_SECCFG | TAMP_HAS_REGISTER_PRIVCFGR,
297 };
298 
299 static const struct stm32_tamp_compat mp15_compat = {
300 	.nb_monotonic_counter = 1,
301 	.tags = 0,
302 };
303 
304 static const struct dt_device_match stm32_tamp_match_table[] = {
305 	{ .compatible = "st,stm32mp13-tamp", .compat_data = &mp13_compat },
306 	{ .compatible = "st,stm32-tamp", .compat_data = &mp15_compat },
307 	{ }
308 };
309 
310 DEFINE_DT_DRIVER(stm32_tamp_dt_driver) = {
311 	.name = "stm32-tamp",
312 	.match_table = stm32_tamp_match_table,
313 	.probe = stm32_tamp_probe,
314 };
315