linux_dsm_epyc7002/arch/arm/mach-shmobile/smp-r8a7791.c
Magnus Damm 277efd30cf ARM: shmobile: Check r8a7791 MD21 at SMP boot
On r8a7791 the hardware boot mode bit MD21 indicates if hardware
debug mode is enabled or not. In case hardware debug mode is enabled
print a warning and refrain from booting secondary CPU cores.

Without this patch Koelsch with SW8-4 set to OFF will hang at SMP boot.

Signed-off-by: Magnus Damm <damm@opensource.se>
Tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
2014-04-14 11:28:43 +09:00

76 lines
2.2 KiB
C

/*
* SMP support for r8a7791
*
* Copyright (C) 2013 Renesas Solutions Corp.
* Copyright (C) 2013 Magnus Damm
*
* 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 of the License.
*
* 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/smp.h>
#include <linux/io.h>
#include <asm/smp_plat.h>
#include <mach/common.h>
#include <mach/r8a7791.h>
#include <mach/rcar-gen2.h>
#define RST 0xe6160000
#define CA15BAR 0x0020
#define CA15RESCNT 0x0040
#define RAM 0xe6300000
static void __init r8a7791_smp_prepare_cpus(unsigned int max_cpus)
{
void __iomem *p;
u32 bar;
/* let APMU code install data related to shmobile_boot_vector */
shmobile_smp_apmu_prepare_cpus(max_cpus);
/* RAM for jump stub, because BAR requires 256KB aligned address */
p = ioremap_nocache(RAM, shmobile_boot_size);
memcpy_toio(p, shmobile_boot_vector, shmobile_boot_size);
iounmap(p);
/* setup reset vectors */
p = ioremap_nocache(RST, 0x63);
bar = (RAM >> 8) & 0xfffffc00;
writel_relaxed(bar, p + CA15BAR);
writel_relaxed(bar | 0x10, p + CA15BAR);
/* enable clocks to all CPUs */
writel_relaxed((readl_relaxed(p + CA15RESCNT) & ~0x0f) | 0xa5a50000,
p + CA15RESCNT);
iounmap(p);
}
static int r8a7791_smp_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
/* Error out when hardware debug mode is enabled */
if (rcar_gen2_read_mode_pins() & BIT(21)) {
pr_warn("Unable to boot CPU%u when MD21 is set\n", cpu);
return -ENOTSUPP;
}
return shmobile_smp_apmu_boot_secondary(cpu, idle);
}
struct smp_operations r8a7791_smp_ops __initdata = {
.smp_prepare_cpus = r8a7791_smp_prepare_cpus,
.smp_boot_secondary = r8a7791_smp_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_disable = shmobile_smp_cpu_disable,
.cpu_die = shmobile_smp_apmu_cpu_die,
.cpu_kill = shmobile_smp_apmu_cpu_kill,
#endif
};