xref: /linux/arch/arm/mach-omap2/omap-secure.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * OMAP Secure API infrastructure.
4  *
5  * Copyright (C) 2011 Texas Instruments, Inc.
6  *	Santosh Shilimkar <santosh.shilimkar@ti.com>
7  * Copyright (C) 2012 Ivaylo Dimitrov <freemangordon@abv.bg>
8  * Copyright (C) 2013 Pali Rohár <pali@kernel.org>
9  */
10 
11 #include <linux/arm-smccc.h>
12 #include <linux/cpu_pm.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/io.h>
16 #include <linux/memblock.h>
17 #include <linux/of.h>
18 
19 #include <asm/cacheflush.h>
20 #include <asm/memblock.h>
21 
22 #include "common.h"
23 #include "omap-secure.h"
24 #include "soc.h"
25 
26 static phys_addr_t omap_secure_memblock_base;
27 
28 bool optee_available;
29 
30 #define OMAP_SIP_SMC_STD_CALL_VAL(func_num) \
31 	ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, ARM_SMCCC_SMC_32, \
32 	ARM_SMCCC_OWNER_SIP, (func_num))
33 
34 static void __init omap_optee_init_check(void)
35 {
36 	struct device_node *np;
37 
38 	/*
39 	 * We only check that the OP-TEE node is present and available. The
40 	 * OP-TEE kernel driver is not needed for the type of interaction made
41 	 * with OP-TEE here so the driver's status is not checked.
42 	 */
43 	np = of_find_node_by_path("/firmware/optee");
44 	if (np && of_device_is_available(np))
45 		optee_available = true;
46 	of_node_put(np);
47 }
48 
49 /**
50  * omap_secure_dispatcher - Routine to dispatch low power secure
51  * service routines
52  * @idx: The HAL API index
53  * @flag: The flag indicating criticality of operation
54  * @nargs: Number of valid arguments out of four.
55  * @arg1, arg2, arg3 args4: Parameters passed to secure API
56  *
57  * Return the non-zero error value on failure.
58  */
59 u32 omap_secure_dispatcher(u32 idx, u32 flag, u32 nargs, u32 arg1, u32 arg2,
60 							 u32 arg3, u32 arg4)
61 {
62 	static u32 buf[NR_CPUS][5];
63 	u32 *param;
64 	int cpu;
65 	u32 ret;
66 
67 	cpu = get_cpu();
68 	param = buf[cpu];
69 
70 	param[0] = nargs;
71 	param[1] = arg1;
72 	param[2] = arg2;
73 	param[3] = arg3;
74 	param[4] = arg4;
75 
76 	/*
77 	 * Secure API needs physical address
78 	 * pointer for the parameters
79 	 */
80 	flush_cache_all();
81 	outer_clean_range(__pa(param), __pa(param + 5));
82 	ret = omap_smc2(idx, flag, __pa(param));
83 
84 	put_cpu();
85 
86 	return ret;
87 }
88 
89 void omap_smccc_smc(u32 fn, u32 arg)
90 {
91 	struct arm_smccc_res res;
92 
93 	arm_smccc_smc(OMAP_SIP_SMC_STD_CALL_VAL(fn), arg,
94 		      0, 0, 0, 0, 0, 0, &res);
95 	WARN(res.a0, "Secure function call 0x%08x failed\n", fn);
96 }
97 
98 void omap_smc1(u32 fn, u32 arg)
99 {
100 	/*
101 	 * If this platform has OP-TEE installed we use ARM SMC calls
102 	 * otherwise fall back to the OMAP ROM style calls.
103 	 */
104 	if (optee_available)
105 		omap_smccc_smc(fn, arg);
106 	else
107 		_omap_smc1(fn, arg);
108 }
109 
110 /* Allocate the memory to save secure ram */
111 int __init omap_secure_ram_reserve_memblock(void)
112 {
113 	u32 size = OMAP_SECURE_RAM_STORAGE;
114 
115 	size = ALIGN(size, SECTION_SIZE);
116 	omap_secure_memblock_base = arm_memblock_steal(size, SECTION_SIZE);
117 
118 	return 0;
119 }
120 
121 #if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_PM)
122 u32 omap3_save_secure_ram(void *addr, int size)
123 {
124 	static u32 param[5];
125 	u32 ret;
126 
127 	if (size != OMAP3_SAVE_SECURE_RAM_SZ)
128 		return OMAP3_SAVE_SECURE_RAM_SZ;
129 
130 	param[0] = 4;		/* Number of arguments */
131 	param[1] = __pa(addr);	/* Physical address for saving */
132 	param[2] = 0;
133 	param[3] = 1;
134 	param[4] = 1;
135 
136 	ret = save_secure_ram_context(__pa(param));
137 
138 	return ret;
139 }
140 #endif
141 
142 /**
143  * rx51_secure_dispatcher: Routine to dispatch secure PPA API calls
144  * @idx: The PPA API index
145  * @process: Process ID
146  * @flag: The flag indicating criticality of operation
147  * @nargs: Number of valid arguments out of four.
148  * @arg1, arg2, arg3 args4: Parameters passed to secure API
149  *
150  * Return the non-zero error value on failure.
151  *
152  * NOTE: rx51_secure_dispatcher differs from omap_secure_dispatcher because
153  *       it calling omap_smc3() instead omap_smc2() and param[0] is nargs+1
154  */
155 static u32 rx51_secure_dispatcher(u32 idx, u32 process, u32 flag, u32 nargs,
156 			   u32 arg1, u32 arg2, u32 arg3, u32 arg4)
157 {
158 	static u32 param[5];
159 	u32 ret;
160 
161 	param[0] = nargs+1; /* RX-51 needs number of arguments + 1 */
162 	param[1] = arg1;
163 	param[2] = arg2;
164 	param[3] = arg3;
165 	param[4] = arg4;
166 
167 	/*
168 	 * Secure API needs physical address
169 	 * pointer for the parameters
170 	 */
171 	local_irq_disable();
172 	local_fiq_disable();
173 	flush_cache_all();
174 	outer_clean_range(__pa(param), __pa(param + 5));
175 	ret = omap_smc3(idx, process, flag, __pa(param));
176 	flush_cache_all();
177 	local_fiq_enable();
178 	local_irq_enable();
179 
180 	return ret;
181 }
182 
183 /**
184  * rx51_secure_update_aux_cr: Routine to modify the contents of Auxiliary Control Register
185  *  @set_bits: bits to set in ACR
186  *  @clear_bits: bits to clear in ACR
187  *
188  * Return the non-zero error value on failure.
189 */
190 u32 rx51_secure_update_aux_cr(u32 set_bits, u32 clear_bits)
191 {
192 	u32 acr;
193 
194 	/* Read ACR */
195 	asm volatile ("mrc p15, 0, %0, c1, c0, 1" : "=r" (acr));
196 	acr &= ~clear_bits;
197 	acr |= set_bits;
198 
199 	return rx51_secure_dispatcher(RX51_PPA_WRITE_ACR,
200 				      0,
201 				      FLAG_START_CRITICAL,
202 				      1, acr, 0, 0, 0);
203 }
204 
205 /**
206  * rx51_secure_rng_call: Routine for HW random generator
207  */
208 u32 rx51_secure_rng_call(u32 ptr, u32 count, u32 flag)
209 {
210 	return rx51_secure_dispatcher(RX51_PPA_HWRNG,
211 				      0,
212 				      NO_FLAG,
213 				      3, ptr, count, flag, 0);
214 }
215 
216 void __init omap_secure_init(void)
217 {
218 	omap_optee_init_check();
219 }
220 
221 /*
222  * Dummy dispatcher call after core OSWR and MPU off. Updates the ROM return
223  * address after MMU has been re-enabled after CPU1 has been woken up again.
224  * Otherwise the ROM code will attempt to use the earlier physical return
225  * address that got set with MMU off when waking up CPU1. Only used on secure
226  * devices.
227  */
228 static int cpu_notifier(struct notifier_block *nb, unsigned long cmd, void *v)
229 {
230 	switch (cmd) {
231 	case CPU_CLUSTER_PM_EXIT:
232 		omap_secure_dispatcher(OMAP4_PPA_SERVICE_0,
233 				       FLAG_START_CRITICAL,
234 				       0, 0, 0, 0, 0);
235 		break;
236 	default:
237 		break;
238 	}
239 
240 	return NOTIFY_OK;
241 }
242 
243 static struct notifier_block secure_notifier_block = {
244 	.notifier_call = cpu_notifier,
245 };
246 
247 static int __init secure_pm_init(void)
248 {
249 	if (omap_type() == OMAP2_DEVICE_TYPE_GP || !soc_is_omap44xx())
250 		return 0;
251 
252 	cpu_pm_register_notifier(&secure_notifier_block);
253 
254 	return 0;
255 }
256 omap_arch_initcall(secure_pm_init);
257