linux/arch/arm/mach-uniphier/platsmp.c
Masahiro Yamada ba56a9876d ARM: UniPhier: add basic support for UniPhier architecture
Initial commit for a new SoC family, UniPhier, developed by
Socionext Inc. (formerly, System LSI Business Division of
Panasonic Corporation).

This commit includes a minimal set of components for booting the
kernel, including SMP support.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2015-05-12 16:55:37 +02:00

91 lines
2.2 KiB
C

/*
* Copyright (C) 2015 Masahiro Yamada <yamada.masahiro@socionext.com>
*
* 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/sizes.h>
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <asm/smp.h>
#include <asm/smp_scu.h>
static struct regmap *sbcm_regmap;
static void __init uniphier_smp_prepare_cpus(unsigned int max_cpus)
{
static cpumask_t only_cpu_0 = { CPU_BITS_CPU0 };
unsigned long scu_base_phys = 0;
void __iomem *scu_base;
sbcm_regmap = syscon_regmap_lookup_by_compatible(
"socionext,uniphier-system-bus-controller-misc");
if (IS_ERR(sbcm_regmap)) {
pr_err("failed to regmap system-bus-controller-misc\n");
goto err;
}
if (scu_a9_has_base())
scu_base_phys = scu_a9_get_base();
if (!scu_base_phys) {
pr_err("failed to get scu base\n");
goto err;
}
scu_base = ioremap(scu_base_phys, SZ_128);
if (!scu_base) {
pr_err("failed to remap scu base (0x%08lx)\n", scu_base_phys);
goto err;
}
scu_enable(scu_base);
iounmap(scu_base);
return;
err:
pr_warn("disabling SMP\n");
init_cpu_present(&only_cpu_0);
sbcm_regmap = NULL;
}
static void __naked uniphier_secondary_startup(void)
{
asm("bl v7_invalidate_l1\n"
"b secondary_startup\n");
};
static int uniphier_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
int ret;
if (!sbcm_regmap)
return -ENODEV;
ret = regmap_write(sbcm_regmap, 0x1208,
virt_to_phys(uniphier_secondary_startup));
if (!ret)
asm("sev"); /* wake up secondary CPU */
return ret;
}
struct smp_operations uniphier_smp_ops __initdata = {
.smp_prepare_cpus = uniphier_smp_prepare_cpus,
.smp_boot_secondary = uniphier_boot_secondary,
};
CPU_METHOD_OF_DECLARE(uniphier_smp, "socionext,uniphier-smp",
&uniphier_smp_ops);