1 /*
2  * Trusted Foundations support for ARM CPUs
3  *
4  * Copyright (c) 2013, NVIDIA Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  */
16 
17 #include <linux/kernel.h>
18 #include <linux/init.h>
19 #include <linux/of.h>
20 
21 #include <linux/firmware/trusted_foundations.h>
22 
23 #include <asm/firmware.h>
24 #include <asm/hardware/cache-l2x0.h>
25 #include <asm/outercache.h>
26 
27 #define TF_CACHE_MAINT		0xfffff100
28 
29 #define TF_CACHE_ENABLE		1
30 #define TF_CACHE_DISABLE	2
31 
32 #define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200
33 
34 #define TF_CPU_PM		0xfffffffc
35 #define TF_CPU_PM_S3		0xffffffe3
36 #define TF_CPU_PM_S2		0xffffffe6
37 #define TF_CPU_PM_S2_NO_MC_CLK	0xffffffe5
38 #define TF_CPU_PM_S1		0xffffffe4
39 #define TF_CPU_PM_S1_NOFLUSH_L2	0xffffffe7
40 
41 static unsigned long cpu_boot_addr;
42 
43 static void tf_generic_smc(u32 type, u32 arg1, u32 arg2)
44 {
45 	register u32 r0 asm("r0") = type;
46 	register u32 r1 asm("r1") = arg1;
47 	register u32 r2 asm("r2") = arg2;
48 
49 	asm volatile(
50 		".arch_extension	sec\n\t"
51 		"stmfd	sp!, {r4 - r11}\n\t"
52 		__asmeq("%0", "r0")
53 		__asmeq("%1", "r1")
54 		__asmeq("%2", "r2")
55 		"mov	r3, #0\n\t"
56 		"mov	r4, #0\n\t"
57 		"smc	#0\n\t"
58 		"ldmfd	sp!, {r4 - r11}\n\t"
59 		:
60 		: "r" (r0), "r" (r1), "r" (r2)
61 		: "memory", "r3", "r12", "lr");
62 }
63 
64 static int tf_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
65 {
66 	cpu_boot_addr = boot_addr;
67 	tf_generic_smc(TF_SET_CPU_BOOT_ADDR_SMC, cpu_boot_addr, 0);
68 
69 	return 0;
70 }
71 
72 static int tf_prepare_idle(unsigned long mode)
73 {
74 	switch (mode) {
75 	case TF_PM_MODE_LP0:
76 		tf_generic_smc(TF_CPU_PM, TF_CPU_PM_S3, cpu_boot_addr);
77 		break;
78 
79 	case TF_PM_MODE_LP1:
80 		tf_generic_smc(TF_CPU_PM, TF_CPU_PM_S2, cpu_boot_addr);
81 		break;
82 
83 	case TF_PM_MODE_LP1_NO_MC_CLK:
84 		tf_generic_smc(TF_CPU_PM, TF_CPU_PM_S2_NO_MC_CLK,
85 			       cpu_boot_addr);
86 		break;
87 
88 	case TF_PM_MODE_LP2:
89 		tf_generic_smc(TF_CPU_PM, TF_CPU_PM_S1, cpu_boot_addr);
90 		break;
91 
92 	case TF_PM_MODE_LP2_NOFLUSH_L2:
93 		tf_generic_smc(TF_CPU_PM, TF_CPU_PM_S1_NOFLUSH_L2,
94 			       cpu_boot_addr);
95 		break;
96 
97 	default:
98 		return -EINVAL;
99 	}
100 
101 	return 0;
102 }
103 
104 #ifdef CONFIG_CACHE_L2X0
105 static void tf_cache_write_sec(unsigned long val, unsigned int reg)
106 {
107 	u32 l2x0_way_mask = 0xff;
108 
109 	switch (reg) {
110 	case L2X0_CTRL:
111 		if (l2x0_saved_regs.aux_ctrl & L310_AUX_CTRL_ASSOCIATIVITY_16)
112 			l2x0_way_mask = 0xffff;
113 
114 		if (val == L2X0_CTRL_EN)
115 			tf_generic_smc(TF_CACHE_MAINT, TF_CACHE_ENABLE,
116 				       l2x0_saved_regs.aux_ctrl);
117 		else
118 			tf_generic_smc(TF_CACHE_MAINT, TF_CACHE_DISABLE,
119 				       l2x0_way_mask);
120 		break;
121 
122 	default:
123 		break;
124 	}
125 }
126 
127 static int tf_init_cache(void)
128 {
129 	outer_cache.write_sec = tf_cache_write_sec;
130 
131 	return 0;
132 }
133 #endif /* CONFIG_CACHE_L2X0 */
134 
135 static const struct firmware_ops trusted_foundations_ops = {
136 	.set_cpu_boot_addr = tf_set_cpu_boot_addr,
137 	.prepare_idle = tf_prepare_idle,
138 #ifdef CONFIG_CACHE_L2X0
139 	.l2x0_init = tf_init_cache,
140 #endif
141 };
142 
143 void register_trusted_foundations(struct trusted_foundations_platform_data *pd)
144 {
145 	/*
146 	 * we are not using version information for now since currently
147 	 * supported SMCs are compatible with all TF releases
148 	 */
149 	register_firmware_ops(&trusted_foundations_ops);
150 }
151 
152 void of_register_trusted_foundations(void)
153 {
154 	struct device_node *node;
155 	struct trusted_foundations_platform_data pdata;
156 	int err;
157 
158 	node = of_find_compatible_node(NULL, NULL, "tlm,trusted-foundations");
159 	if (!node)
160 		return;
161 
162 	err = of_property_read_u32(node, "tlm,version-major",
163 				   &pdata.version_major);
164 	if (err != 0)
165 		panic("Trusted Foundation: missing version-major property\n");
166 	err = of_property_read_u32(node, "tlm,version-minor",
167 				   &pdata.version_minor);
168 	if (err != 0)
169 		panic("Trusted Foundation: missing version-minor property\n");
170 	register_trusted_foundations(&pdata);
171 }
172 
173 bool trusted_foundations_registered(void)
174 {
175 	return firmware_ops == &trusted_foundations_ops;
176 }
177