xref: /linux/arch/arm/mach-bcm/bcm_kona_smc.c (revision 3a76b35186cb967a69c4a3935caf2fdf428e933b)
1 /*
2  * Copyright (C) 2013 Broadcom Corporation
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License as
6  * published by the Free Software Foundation version 2.
7  *
8  * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9  * kind, whether express or implied; without even the implied warranty
10  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  */
13 
14 #include <stdarg.h>
15 #include <linux/smp.h>
16 #include <linux/io.h>
17 #include <linux/ioport.h>
18 
19 #include <asm/cacheflush.h>
20 #include <linux/of_address.h>
21 
22 #include "bcm_kona_smc.h"
23 
24 struct secure_bridge_data {
25 	void __iomem *bounce;		/* virtual address */
26 	u32 __iomem buffer_addr;	/* physical address */
27 	int initialized;
28 } bridge_data;
29 
30 struct bcm_kona_smc_data {
31 	unsigned service_id;
32 	unsigned arg0;
33 	unsigned arg1;
34 	unsigned arg2;
35 	unsigned arg3;
36 };
37 
38 static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
39 	{.compatible = "brcm,kona-smc"},
40 	{.compatible = "bcm,kona-smc"}, /* deprecated name */
41 	{},
42 };
43 
44 /* Map in the bounce area */
45 int __init bcm_kona_smc_init(void)
46 {
47 	struct device_node *node;
48 
49 	/* Read buffer addr and size from the device tree node */
50 	node = of_find_matching_node(NULL, bcm_kona_smc_ids);
51 	if (!node)
52 		return -ENODEV;
53 
54 	/* Don't care about size or flags of the DT node */
55 	bridge_data.buffer_addr =
56 		be32_to_cpu(*of_get_address(node, 0, NULL, NULL));
57 	BUG_ON(!bridge_data.buffer_addr);
58 
59 	bridge_data.bounce = of_iomap(node, 0);
60 	BUG_ON(!bridge_data.bounce);
61 
62 	bridge_data.initialized = 1;
63 
64 	pr_info("Kona Secure API initialized\n");
65 
66 	return 0;
67 }
68 
69 /* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
70 static void __bcm_kona_smc(void *info)
71 {
72 	struct bcm_kona_smc_data *data = info;
73 	u32 *args = bridge_data.bounce;
74 	int rc = 0;
75 
76 	/* Must run on CPU 0 */
77 	BUG_ON(smp_processor_id() != 0);
78 
79 	/* Check map in the bounce area */
80 	BUG_ON(!bridge_data.initialized);
81 
82 	/* Copy one 32 bit word into the bounce area */
83 	args[0] = data->arg0;
84 	args[1] = data->arg1;
85 	args[2] = data->arg2;
86 	args[3] = data->arg3;
87 
88 	/* Flush caches for input data passed to Secure Monitor */
89 	if (data->service_id != SSAPI_BRCM_START_VC_CORE)
90 		flush_cache_all();
91 
92 	/* Trap into Secure Monitor */
93 	rc = bcm_kona_smc_asm(data->service_id, bridge_data.buffer_addr);
94 
95 	if (rc != SEC_ROM_RET_OK)
96 		pr_err("Secure Monitor call failed (0x%x)!\n", rc);
97 }
98 
99 unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
100 		  unsigned arg2, unsigned arg3)
101 {
102 	struct bcm_kona_smc_data data;
103 
104 	data.service_id = service_id;
105 	data.arg0 = arg0;
106 	data.arg1 = arg1;
107 	data.arg2 = arg2;
108 	data.arg3 = arg3;
109 
110 	/*
111 	 * Due to a limitation of the secure monitor, we must use the SMP
112 	 * infrastructure to forward all secure monitor calls to Core 0.
113 	 */
114 	if (get_cpu() != 0)
115 		smp_call_function_single(0, __bcm_kona_smc, (void *)&data, 1);
116 	else
117 		__bcm_kona_smc(&data);
118 
119 	put_cpu();
120 
121 	return 0;
122 }
123