1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * arch/arm/mach-tegra/reset.c
4  *
5  * Copyright (C) 2011,2012 NVIDIA Corporation.
6  */
7 
8 #include <linux/bitops.h>
9 #include <linux/cpumask.h>
10 #include <linux/init.h>
11 #include <linux/io.h>
12 
13 #include <linux/firmware/trusted_foundations.h>
14 
15 #include <soc/tegra/fuse.h>
16 
17 #include <asm/cacheflush.h>
18 #include <asm/firmware.h>
19 #include <asm/hardware/cache-l2x0.h>
20 
21 #include "iomap.h"
22 #include "irammap.h"
23 #include "reset.h"
24 #include "sleep.h"
25 
26 #define TEGRA_IRAM_RESET_BASE (TEGRA_IRAM_BASE + \
27 				TEGRA_IRAM_RESET_HANDLER_OFFSET)
28 
29 static bool is_enabled;
30 
tegra_cpu_reset_handler_set(const u32 reset_address)31 static void __init tegra_cpu_reset_handler_set(const u32 reset_address)
32 {
33 	void __iomem *evp_cpu_reset =
34 		IO_ADDRESS(TEGRA_EXCEPTION_VECTORS_BASE + 0x100);
35 	void __iomem *sb_ctrl = IO_ADDRESS(TEGRA_SB_BASE);
36 	u32 reg;
37 
38 	/*
39 	 * NOTE: This must be the one and only write to the EVP CPU reset
40 	 *       vector in the entire system.
41 	 */
42 	writel(reset_address, evp_cpu_reset);
43 	wmb();
44 	reg = readl(evp_cpu_reset);
45 
46 	/*
47 	 * Prevent further modifications to the physical reset vector.
48 	 *  NOTE: Has no effect on chips prior to Tegra30.
49 	 */
50 	reg = readl(sb_ctrl);
51 	reg |= 2;
52 	writel(reg, sb_ctrl);
53 	wmb();
54 }
55 
tegra_cpu_reset_handler_enable(void)56 static void __init tegra_cpu_reset_handler_enable(void)
57 {
58 	void __iomem *iram_base = IO_ADDRESS(TEGRA_IRAM_RESET_BASE);
59 	const u32 reset_address = TEGRA_IRAM_RESET_BASE +
60 						tegra_cpu_reset_handler_offset;
61 	int err;
62 
63 	BUG_ON(is_enabled);
64 	BUG_ON(tegra_cpu_reset_handler_size > TEGRA_IRAM_RESET_HANDLER_SIZE);
65 
66 	memcpy(iram_base, (void *)__tegra_cpu_reset_handler_start,
67 			tegra_cpu_reset_handler_size);
68 
69 	err = call_firmware_op(set_cpu_boot_addr, 0, reset_address);
70 	switch (err) {
71 	case -ENOSYS:
72 		tegra_cpu_reset_handler_set(reset_address);
73 		fallthrough;
74 	case 0:
75 		is_enabled = true;
76 		break;
77 	default:
78 		pr_crit("Cannot set CPU reset handler: %d\n", err);
79 		BUG();
80 	}
81 }
82 
tegra_cpu_reset_handler_init(void)83 void __init tegra_cpu_reset_handler_init(void)
84 {
85 	__tegra_cpu_reset_handler_data[TEGRA_RESET_TF_PRESENT] =
86 		trusted_foundations_registered();
87 
88 #ifdef CONFIG_SMP
89 	__tegra_cpu_reset_handler_data[TEGRA_RESET_MASK_PRESENT] =
90 		*((u32 *)cpu_possible_mask);
91 	__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_SECONDARY] =
92 		__pa_symbol((void *)secondary_startup);
93 #endif
94 
95 #ifdef CONFIG_PM_SLEEP
96 	__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP1] =
97 		TEGRA_IRAM_LPx_RESUME_AREA;
98 	__tegra_cpu_reset_handler_data[TEGRA_RESET_STARTUP_LP2] =
99 		__pa_symbol((void *)tegra_resume);
100 #endif
101 
102 	tegra_cpu_reset_handler_enable();
103 }
104