cregit-Linux how code gets into the kernel

Release 4.11 arch/arm/mach-bcm/bcm_kona_smc.c

/*
 * Copyright (C) 2013 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <stdarg.h>
#include <linux/smp.h>
#include <linux/io.h>
#include <linux/ioport.h>

#include <asm/cacheflush.h>
#include <linux/of_address.h>

#include "bcm_kona_smc.h"


static u32		bcm_smc_buffer_phys;	
/* physical address */

static void __iomem	*bcm_smc_buffer;	
/* virtual address */


struct bcm_kona_smc_data {
	
unsigned service_id;
	
unsigned arg0;
	
unsigned arg1;
	
unsigned arg2;
	
unsigned arg3;
	
unsigned result;
};


static const struct of_device_id const bcm_kona_smc_ids[] __initconst = {
	{.compatible = "brcm,kona-smc"},
	{.compatible = "bcm,kona-smc"}, /* deprecated name */
	{},
};

/* Map in the args buffer area */

int __init bcm_kona_smc_init(void) { struct device_node *node; const __be32 *prop_val; u64 prop_size = 0; unsigned long buffer_size; u32 buffer_phys; /* Read buffer addr and size from the device tree node */ node = of_find_matching_node(NULL, bcm_kona_smc_ids); if (!node) return -ENODEV; prop_val = of_get_address(node, 0, &prop_size, NULL); if (!prop_val) return -EINVAL; /* We assume space for four 32-bit arguments */ if (prop_size < 4 * sizeof(u32) || prop_size > (u64)ULONG_MAX) return -EINVAL; buffer_size = (unsigned long)prop_size; buffer_phys = be32_to_cpup(prop_val); if (!buffer_phys) return -EINVAL; bcm_smc_buffer = ioremap(buffer_phys, buffer_size); if (!bcm_smc_buffer) return -ENOMEM; bcm_smc_buffer_phys = buffer_phys; pr_info("Kona Secure API initialized\n"); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Elder8758.39%240.00%
Christian Daudt6140.94%240.00%
Arnd Bergmann10.67%120.00%
Total149100.00%5100.00%

/* * int bcm_kona_do_smc(u32 service_id, u32 buffer_addr) * * Only core 0 can run the secure monitor code. If an "smc" request * is initiated on a different core it must be redirected to core 0 * for execution. We rely on the caller to handle this. * * Each "smc" request supplies a service id and the address of a * buffer containing parameters related to the service to be * performed. A flags value defines the behavior of the level 2 * cache and interrupt handling while the secure monitor executes. * * Parameters to the "smc" request are passed in r4-r6 as follows: * r4 service id * r5 flags (SEC_ROM_*) * r6 physical address of buffer with other parameters * * Execution of an "smc" request produces two distinct results. * * First, the secure monitor call itself (regardless of the specific * service request) can succeed, or can produce an error. When an * "smc" request completes this value is found in r12; it should * always be SEC_EXIT_NORMAL. * * In addition, the particular service performed produces a result. * The values that should be expected depend on the service. We * therefore return this value to the caller, so it can handle the * request result appropriately. This result value is found in r0 * when the "smc" request completes. */
static int bcm_kona_do_smc(u32 service_id, u32 buffer_phys) { register u32 ip asm("ip"); /* Also called r12 */ register u32 r0 asm("r0"); register u32 r4 asm("r4"); register u32 r5 asm("r5"); register u32 r6 asm("r6"); r4 = service_id; r5 = 0x3; /* Keep IRQ and FIQ off in SM */ r6 = buffer_phys; asm volatile ( /* Make sure we got the registers we want */ __asmeq("%0", "ip") __asmeq("%1", "r0") __asmeq("%2", "r4") __asmeq("%3", "r5") __asmeq("%4", "r6") #ifdef REQUIRES_SEC ".arch_extension sec\n" #endif " smc #0\n" : "=r" (ip), "=r" (r0) : "r" (r4), "r" (r5), "r" (r6) : "r1", "r2", "r3", "r7", "lr"); BUG_ON(ip != SEC_EXIT_NORMAL); return r0; }

Contributors

PersonTokensPropCommitsCommitProp
Alex Elder88100.00%1100.00%
Total88100.00%1100.00%

/* __bcm_kona_smc() should only run on CPU 0, with pre-emption disabled */
static void __bcm_kona_smc(void *info) { struct bcm_kona_smc_data *data = info; u32 *args = bcm_smc_buffer; BUG_ON(smp_processor_id() != 0); BUG_ON(!args); /* Copy the four 32 bit argument values into the bounce area */ writel_relaxed(data->arg0, args++); writel_relaxed(data->arg1, args++); writel_relaxed(data->arg2, args++); writel(data->arg3, args); /* Flush caches for input data passed to Secure Monitor */ flush_cache_all(); /* Trap into Secure Monitor and record the request result */ data->result = bcm_kona_do_smc(data->service_id, bcm_smc_buffer_phys); }

Contributors

PersonTokensPropCommitsCommitProp
Christian Daudt6366.32%120.00%
Alex Elder3233.68%480.00%
Total95100.00%5100.00%


unsigned bcm_kona_smc(unsigned service_id, unsigned arg0, unsigned arg1, unsigned arg2, unsigned arg3) { struct bcm_kona_smc_data data; data.service_id = service_id; data.arg0 = arg0; data.arg1 = arg1; data.arg2 = arg2; data.arg3 = arg3; data.result = 0; /* * Due to a limitation of the secure monitor, we must use the SMP * infrastructure to forward all secure monitor calls to Core 0. */ smp_call_function_single(0, __bcm_kona_smc, &data, 1); return data.result; }

Contributors

PersonTokensPropCommitsCommitProp
Christian Daudt6988.46%150.00%
Alex Elder911.54%150.00%
Total78100.00%2100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
Christian Daudt26853.82%327.27%
Alex Elder22845.78%654.55%
Nico Pitre10.20%19.09%
Arnd Bergmann10.20%19.09%
Total498100.00%11100.00%
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