xref: /openbmc/linux/arch/arm/mach-bcm/bcm_kona_smc.c (revision f35e839a)
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 = "bcm,kona-smc"},
40 	{},
41 };
42 
43 /* Map in the bounce area */
44 void __init bcm_kona_smc_init(void)
45 {
46 	struct device_node *node;
47 
48 	/* Read buffer addr and size from the device tree node */
49 	node = of_find_matching_node(NULL, bcm_kona_smc_ids);
50 	BUG_ON(!node);
51 
52 	/* Don't care about size or flags of the DT node */
53 	bridge_data.buffer_addr =
54 		be32_to_cpu(*of_get_address(node, 0, NULL, NULL));
55 	BUG_ON(!bridge_data.buffer_addr);
56 
57 	bridge_data.bounce = of_iomap(node, 0);
58 	BUG_ON(!bridge_data.bounce);
59 
60 	bridge_data.initialized = 1;
61 
62 	pr_info("Secure API initialized!\n");
63 }
64 
65 /* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
66 static void __bcm_kona_smc(void *info)
67 {
68 	struct bcm_kona_smc_data *data = info;
69 	u32 *args = bridge_data.bounce;
70 	int rc = 0;
71 
72 	/* Must run on CPU 0 */
73 	BUG_ON(smp_processor_id() != 0);
74 
75 	/* Check map in the bounce area */
76 	BUG_ON(!bridge_data.initialized);
77 
78 	/* Copy one 32 bit word into the bounce area */
79 	args[0] = data->arg0;
80 	args[1] = data->arg1;
81 	args[2] = data->arg2;
82 	args[3] = data->arg3;
83 
84 	/* Flush caches for input data passed to Secure Monitor */
85 	if (data->service_id != SSAPI_BRCM_START_VC_CORE)
86 		flush_cache_all();
87 
88 	/* Trap into Secure Monitor */
89 	rc = bcm_kona_smc_asm(data->service_id, bridge_data.buffer_addr);
90 
91 	if (rc != SEC_ROM_RET_OK)
92 		pr_err("Secure Monitor call failed (0x%x)!\n", rc);
93 }
94 
95 unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
96 		  unsigned arg2, unsigned arg3)
97 {
98 	struct bcm_kona_smc_data data;
99 
100 	data.service_id = service_id;
101 	data.arg0 = arg0;
102 	data.arg1 = arg1;
103 	data.arg2 = arg2;
104 	data.arg3 = arg3;
105 
106 	/*
107 	 * Due to a limitation of the secure monitor, we must use the SMP
108 	 * infrastructure to forward all secure monitor calls to Core 0.
109 	 */
110 	if (get_cpu() != 0)
111 		smp_call_function_single(0, __bcm_kona_smc, (void *)&data, 1);
112 	else
113 		__bcm_kona_smc(&data);
114 
115 	put_cpu();
116 
117 	return 0;
118 }
119