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 #include <asm/firmware.h>
21 #include <asm/trusted_foundations.h>
22 
23 #define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200
24 
25 #define TF_CPU_PM		0xfffffffc
26 #define TF_CPU_PM_S3		0xffffffe3
27 #define TF_CPU_PM_S2		0xffffffe6
28 #define TF_CPU_PM_S2_NO_MC_CLK	0xffffffe5
29 #define TF_CPU_PM_S1		0xffffffe4
30 #define TF_CPU_PM_S1_NOFLUSH_L2	0xffffffe7
31 
32 static unsigned long cpu_boot_addr;
33 
tf_generic_smc(u32 type,u32 arg1,u32 arg2)34 static void tf_generic_smc(u32 type, u32 arg1, u32 arg2)
35 {
36 	register u32 r0 asm("r0") = type;
37 	register u32 r1 asm("r1") = arg1;
38 	register u32 r2 asm("r2") = arg2;
39 
40 	asm volatile(
41 		".arch_extension	sec\n\t"
42 		"stmfd	sp!, {r4 - r11}\n\t"
43 		__asmeq("%0", "r0")
44 		__asmeq("%1", "r1")
45 		__asmeq("%2", "r2")
46 		"mov	r3, #0\n\t"
47 		"mov	r4, #0\n\t"
48 		"smc	#0\n\t"
49 		"ldmfd	sp!, {r4 - r11}\n\t"
50 		:
51 		: "r" (r0), "r" (r1), "r" (r2)
52 		: "memory", "r3", "r12", "lr");
53 }
54 
tf_set_cpu_boot_addr(int cpu,unsigned long boot_addr)55 static int tf_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
56 {
57 	cpu_boot_addr = boot_addr;
58 	tf_generic_smc(TF_SET_CPU_BOOT_ADDR_SMC, cpu_boot_addr, 0);
59 
60 	return 0;
61 }
62 
tf_prepare_idle(void)63 static int tf_prepare_idle(void)
64 {
65 	tf_generic_smc(TF_CPU_PM, TF_CPU_PM_S1_NOFLUSH_L2, cpu_boot_addr);
66 
67 	return 0;
68 }
69 
70 static const struct firmware_ops trusted_foundations_ops = {
71 	.set_cpu_boot_addr = tf_set_cpu_boot_addr,
72 	.prepare_idle = tf_prepare_idle,
73 };
74 
register_trusted_foundations(struct trusted_foundations_platform_data * pd)75 void register_trusted_foundations(struct trusted_foundations_platform_data *pd)
76 {
77 	/*
78 	 * we are not using version information for now since currently
79 	 * supported SMCs are compatible with all TF releases
80 	 */
81 	register_firmware_ops(&trusted_foundations_ops);
82 }
83 
of_register_trusted_foundations(void)84 void of_register_trusted_foundations(void)
85 {
86 	struct device_node *node;
87 	struct trusted_foundations_platform_data pdata;
88 	int err;
89 
90 	node = of_find_compatible_node(NULL, NULL, "tlm,trusted-foundations");
91 	if (!node)
92 		return;
93 
94 	err = of_property_read_u32(node, "tlm,version-major",
95 				   &pdata.version_major);
96 	if (err != 0)
97 		panic("Trusted Foundation: missing version-major property\n");
98 	err = of_property_read_u32(node, "tlm,version-minor",
99 				   &pdata.version_minor);
100 	if (err != 0)
101 		panic("Trusted Foundation: missing version-minor property\n");
102 	register_trusted_foundations(&pdata);
103 }
104