2 * Copyright (C) 2013 Broadcom Corporation
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.
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.
15 #include <linux/smp.h>
17 #include <linux/ioport.h>
19 #include <asm/cacheflush.h>
20 #include <linux/of_address.h>
22 #include "bcm_kona_smc.h"
24 static u32 bcm_smc_buffer_phys
; /* physical address */
25 static void __iomem
*bcm_smc_buffer
; /* virtual address */
27 struct bcm_kona_smc_data
{
36 static const struct of_device_id bcm_kona_smc_ids
[] __initconst
= {
37 {.compatible
= "brcm,kona-smc"},
38 {.compatible
= "bcm,kona-smc"}, /* deprecated name */
42 /* Map in the args buffer area */
43 int __init
bcm_kona_smc_init(void)
45 struct device_node
*node
;
46 const __be32
*prop_val
;
48 unsigned long buffer_size
;
51 /* Read buffer addr and size from the device tree node */
52 node
= of_find_matching_node(NULL
, bcm_kona_smc_ids
);
56 prop_val
= of_get_address(node
, 0, &prop_size
, NULL
);
60 /* We assume space for four 32-bit arguments */
61 if (prop_size
< 4 * sizeof(u32
) || prop_size
> (u64
)ULONG_MAX
)
63 buffer_size
= (unsigned long)prop_size
;
65 buffer_phys
= be32_to_cpup(prop_val
);
69 bcm_smc_buffer
= ioremap(buffer_phys
, buffer_size
);
72 bcm_smc_buffer_phys
= buffer_phys
;
74 pr_info("Kona Secure API initialized\n");
80 * int bcm_kona_do_smc(u32 service_id, u32 buffer_addr)
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.
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.
91 * Parameters to the "smc" request are passed in r4-r6 as follows:
93 * r5 flags (SEC_ROM_*)
94 * r6 physical address of buffer with other parameters
96 * Execution of an "smc" request produces two distinct results.
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.
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.
109 static int bcm_kona_do_smc(u32 service_id
, u32 buffer_phys
)
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");
118 r5
= 0x3; /* Keep IRQ and FIQ off in SM */
122 /* Make sure we got the registers we want */
128 ".arch_extension sec\n"
130 : "=r" (ip
), "=r" (r0
)
131 : "r" (r4
), "r" (r5
), "r" (r6
)
132 : "r1", "r2", "r3", "r7", "lr");
134 BUG_ON(ip
!= SEC_EXIT_NORMAL
);
139 /* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
140 static void __bcm_kona_smc(void *info
)
142 struct bcm_kona_smc_data
*data
= info
;
143 u32 __iomem
*args
= bcm_smc_buffer
;
145 BUG_ON(smp_processor_id() != 0);
148 /* Copy the four 32 bit argument values into the bounce area */
149 writel_relaxed(data
->arg0
, args
++);
150 writel_relaxed(data
->arg1
, args
++);
151 writel_relaxed(data
->arg2
, args
++);
152 writel(data
->arg3
, args
);
154 /* Flush caches for input data passed to Secure Monitor */
157 /* Trap into Secure Monitor and record the request result */
158 data
->result
= bcm_kona_do_smc(data
->service_id
, bcm_smc_buffer_phys
);
161 unsigned bcm_kona_smc(unsigned service_id
, unsigned arg0
, unsigned arg1
,
162 unsigned arg2
, unsigned arg3
)
164 struct bcm_kona_smc_data data
;
166 data
.service_id
= service_id
;
174 * Due to a limitation of the secure monitor, we must use the SMP
175 * infrastructure to forward all secure monitor calls to Core 0.
177 smp_call_function_single(0, __bcm_kona_smc
, &data
, 1);