arch/arm/mach-bcm/bcm_kona_smc.c

   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 }