linux_kernel/arch/arm/firmware/trusted_foundations.c

/*
 * Trusted Foundations support for ARM CPUs
 *
 * Copyright (c) 2013, NVIDIA 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of.h>
#include <asm/firmware.h>
#include <asm/trusted_foundations.h>

#define TF_SET_CPU_BOOT_ADDR_SMC 0xfffff200

static void __naked tf_generic_smc(u32 type, u32 arg1, u32 arg2)
{
	asm volatile(
		".arch_extension	sec\n\t"
		"stmfd	sp!, {r4 - r11, lr}\n\t"
		__asmeq("%0", "r0")
		__asmeq("%1", "r1")
		__asmeq("%2", "r2")
		"mov	r3, #0\n\t"
		"mov	r4, #0\n\t"
		"smc	#0\n\t"
		"ldmfd	sp!, {r4 - r11, pc}"
		:
		: "r" (type), "r" (arg1), "r" (arg2)
		: "memory");
}

static int tf_set_cpu_boot_addr(int cpu, unsigned long boot_addr)
{
	tf_generic_smc(TF_SET_CPU_BOOT_ADDR_SMC, boot_addr, 0);

	return 0;
}

static const struct firmware_ops trusted_foundations_ops = {
	.set_cpu_boot_addr = tf_set_cpu_boot_addr,
};

void register_trusted_foundations(struct trusted_foundations_platform_data *pd)
{
	/*
	 * we are not using version information for now since currently
	 * supported SMCs are compatible with all TF releases
	 */
	register_firmware_ops(&trusted_foundations_ops);
}

void of_register_trusted_foundations(void)
{
	struct device_node *node;
	struct trusted_foundations_platform_data pdata;
	int err;

	node = of_find_compatible_node(NULL, NULL, "tlm,trusted-foundations");
	if (!node)
		return;

	err = of_property_read_u32(node, "tlm,version-major",
				   &pdata.version_major);
	if (err != 0)
		panic("Trusted Foundation: missing version-major property\n");
	err = of_property_read_u32(node, "tlm,version-minor",
				   &pdata.version_minor);
	if (err != 0)
		panic("Trusted Foundation: missing version-minor property\n");
	register_trusted_foundations(&pdata);
}