1 /*
2  * Copyright (c) 2013, NVIDIA Corporation.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License as published by
6  * the Free Software Foundation; either version 2 of the License, or
7  * (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but WITHOUT
10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12  * more details.
13  */
14 
15 /*
16  * Support for the Trusted Foundations secure monitor.
17  *
18  * Trusted Foundation comes active on some ARM consumer devices (most
19  * Tegra-based devices sold on the market are concerned). Such devices can only
20  * perform some basic operations, like setting the CPU reset vector, through
21  * SMC calls to the secure monitor. The calls are completely specific to
22  * Trusted Foundations, and do *not* follow the SMC calling convention or the
23  * PSCI standard.
24  */
25 
26 #ifndef __FIRMWARE_TRUSTED_FOUNDATIONS_H
27 #define __FIRMWARE_TRUSTED_FOUNDATIONS_H
28 
29 #include <linux/printk.h>
30 #include <linux/bug.h>
31 #include <linux/of.h>
32 #include <linux/cpu.h>
33 #include <linux/smp.h>
34 #include <linux/types.h>
35 
36 #include <asm/hardware/cache-l2x0.h>
37 #include <asm/outercache.h>
38 
39 #define TF_PM_MODE_LP0			0
40 #define TF_PM_MODE_LP1			1
41 #define TF_PM_MODE_LP1_NO_MC_CLK	2
42 #define TF_PM_MODE_LP2			3
43 #define TF_PM_MODE_LP2_NOFLUSH_L2	4
44 
45 struct trusted_foundations_platform_data {
46 	unsigned int version_major;
47 	unsigned int version_minor;
48 };
49 
50 #if IS_ENABLED(CONFIG_TRUSTED_FOUNDATIONS)
51 
52 void register_trusted_foundations(struct trusted_foundations_platform_data *pd);
53 void of_register_trusted_foundations(void);
54 bool trusted_foundations_registered(void);
55 
56 #else /* CONFIG_TRUSTED_FOUNDATIONS */
57 static inline void tf_dummy_write_sec(unsigned long val, unsigned int reg)
58 {
59 }
60 
61 static inline void register_trusted_foundations(
62 				   struct trusted_foundations_platform_data *pd)
63 {
64 	/*
65 	 * If the system requires TF and we cannot provide it, continue booting
66 	 * but disable features that cannot be provided.
67 	 */
68 	pr_err("No support for Trusted Foundations, continuing in degraded mode.\n");
69 	pr_err("Secondary processors as well as CPU PM will be disabled.\n");
70 #if IS_ENABLED(CONFIG_CACHE_L2X0)
71 	pr_err("L2X0 cache will be kept disabled.\n");
72 	outer_cache.write_sec = tf_dummy_write_sec;
73 #endif
74 #if IS_ENABLED(CONFIG_SMP)
75 	setup_max_cpus = 0;
76 #endif
77 	cpu_idle_poll_ctrl(true);
78 }
79 
80 static inline void of_register_trusted_foundations(void)
81 {
82 	/*
83 	 * If we find the target should enable TF but does not support it,
84 	 * fail as the system won't be able to do much anyway
85 	 */
86 	if (of_find_compatible_node(NULL, NULL, "tlm,trusted-foundations"))
87 		register_trusted_foundations(NULL);
88 }
89 
90 static inline bool trusted_foundations_registered(void)
91 {
92 	return false;
93 }
94 #endif /* CONFIG_TRUSTED_FOUNDATIONS */
95 
96 #endif
97