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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
24static u32 bcm_smc_buffer_phys; /* physical address */
25static void __iomem *bcm_smc_buffer; /* virtual address */
26
27struct bcm_kona_smc_data {
28 unsigned service_id;
29 unsigned arg0;
30 unsigned arg1;
31 unsigned arg2;
32 unsigned arg3;
33 unsigned result;
34};
35
36static const struct of_device_id bcm_kona_smc_ids[] __initconst = {
37 {.compatible = "brcm,kona-smc"},
38 {.compatible = "bcm,kona-smc"}, /* deprecated name */
39 {},
40};
41
42/* Map in the args buffer area */
43int __init bcm_kona_smc_init(void)
44{
45 struct device_node *node;
46 const __be32 *prop_val;
47 u64 prop_size = 0;
48 unsigned long buffer_size;
49 u32 buffer_phys;
50
51 /* Read buffer addr and size from the device tree node */
52 node = of_find_matching_node(NULL, bcm_kona_smc_ids);
53 if (!node)
54 return -ENODEV;
55
56 prop_val = of_get_address(node, 0, &prop_size, NULL);
57 if (!prop_val)
58 return -EINVAL;
59
60 /* We assume space for four 32-bit arguments */
61 if (prop_size < 4 * sizeof(u32) || prop_size > (u64)ULONG_MAX)
62 return -EINVAL;
63 buffer_size = (unsigned long)prop_size;
64
65 buffer_phys = be32_to_cpup(prop_val);
66 if (!buffer_phys)
67 return -EINVAL;
68
69 bcm_smc_buffer = ioremap(buffer_phys, buffer_size);
70 if (!bcm_smc_buffer)
71 return -ENOMEM;
72 bcm_smc_buffer_phys = buffer_phys;
73
74 pr_info("Kona Secure API initialized\n");
75
76 return 0;
77}
78
79/*
80 * int bcm_kona_do_smc(u32 service_id, u32 buffer_addr)
81 *
82 * Only core 0 can run the secure monitor code. If an "smc" request
83 * is initiated on a different core it must be redirected to core 0
84 * for execution. We rely on the caller to handle this.
85 *
86 * Each "smc" request supplies a service id and the address of a
87 * buffer containing parameters related to the service to be
88 * performed. A flags value defines the behavior of the level 2
89 * cache and interrupt handling while the secure monitor executes.
90 *
91 * Parameters to the "smc" request are passed in r4-r6 as follows:
92 * r4 service id
93 * r5 flags (SEC_ROM_*)
94 * r6 physical address of buffer with other parameters
95 *
96 * Execution of an "smc" request produces two distinct results.
97 *
98 * First, the secure monitor call itself (regardless of the specific
99 * service request) can succeed, or can produce an error. When an
100 * "smc" request completes this value is found in r12; it should
101 * always be SEC_EXIT_NORMAL.
102 *
103 * In addition, the particular service performed produces a result.
104 * The values that should be expected depend on the service. We
105 * therefore return this value to the caller, so it can handle the
106 * request result appropriately. This result value is found in r0
107 * when the "smc" request completes.
108 */
109static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys)
110{
111 register u32 ip asm("ip"); /* Also called r12 */
112 register u32 r0 asm("r0");
113 register u32 r4 asm("r4");
114 register u32 r5 asm("r5");
115 register u32 r6 asm("r6");
116
117 r4 = service_id;
118 r5 = 0x3; /* Keep IRQ and FIQ off in SM */
119 r6 = buffer_phys;
120
121 asm volatile (
122 /* Make sure we got the registers we want */
123 __asmeq("%0", "ip")
124 __asmeq("%1", "r0")
125 __asmeq("%2", "r4")
126 __asmeq("%3", "r5")
127 __asmeq("%4", "r6")
128#ifdef REQUIRES_SEC
129 ".arch_extension sec\n"
130#endif
131 " smc #0\n"
132 : "=r" (ip), "=r" (r0)
133 : "r" (r4), "r" (r5), "r" (r6)
134 : "r1", "r2", "r3", "r7", "lr");
135
136 BUG_ON(ip != SEC_EXIT_NORMAL);
137
138 return r0;
139}
140
141/* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
142static void __bcm_kona_smc(void *info)
143{
144 struct bcm_kona_smc_data *data = info;
145 u32 *args = bcm_smc_buffer;
146
147 BUG_ON(smp_processor_id() != 0);
148 BUG_ON(!args);
149
150 /* Copy the four 32 bit argument values into the bounce area */
151 writel_relaxed(data->arg0, args++);
152 writel_relaxed(data->arg1, args++);
153 writel_relaxed(data->arg2, args++);
154 writel(data->arg3, args);
155
156 /* Flush caches for input data passed to Secure Monitor */
157 flush_cache_all();
158
159 /* Trap into Secure Monitor and record the request result */
160 data->result = bcm_kona_do_smc(data->service_id, bcm_smc_buffer_phys);
161}
162
163unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1,
164 unsigned arg2, unsigned arg3)
165{
166 struct bcm_kona_smc_data data;
167
168 data.service_id = service_id;
169 data.arg0 = arg0;
170 data.arg1 = arg1;
171 data.arg2 = arg2;
172 data.arg3 = arg3;
173 data.result = 0;
174
175 /*
176 * Due to a limitation of the secure monitor, we must use the SMP
177 * infrastructure to forward all secure monitor calls to Core 0.
178 */
179 smp_call_function_single(0, __bcm_kona_smc, &data, 1);
180
181 return data.result;
182}
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
24struct secure_bridge_data {
25 void __iomem *bounce; /* virtual address */
26 u32 __iomem buffer_addr; /* physical address */
27 int initialized;
28} bridge_data;
29
30struct bcm_kona_smc_data {
31 unsigned service_id;
32 unsigned arg0;
33 unsigned arg1;
34 unsigned arg2;
35 unsigned arg3;
36};
37
38static 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 */
45int __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 */
70static 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
99unsigned 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}