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linux-next/arch/arm/mach-mvebu/platsmp-a9.c
Gregory CLEMENT 87384cc0b4 ARM: mvebu: add workaround for SMP support for Armada 375 stepping Z1
Due to internal bootrom issue, CPU[1] initial jump code (four
instructions) should be placed in SRAM memory of the SoC. In order to
achieve this, we have to unmap the BootROM and at some specific
location where the BootROM was place, create a specific MBus window
for the SRAM. This SRAM is initialized with a few instructions of code
that allows to jump into the real secondary CPU boot address.

This workaround will most likely be disabled when newer steppings of
the Armada 375 will be made available, in which case a dynamic test
based on mvebu-soc-id will be added.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-10-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Link: https://lkml.kernel.org/r/1397483648-26611-10-git-send-email-thomas.petazzoni@free-electrons.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
2014-05-08 16:08:30 +00:00

101 lines
2.8 KiB
C

/*
* Symmetric Multi Processing (SMP) support for Marvell EBU Cortex-A9
* based SOCs (Armada 375/38x).
*
* Copyright (C) 2014 Marvell
*
* Gregory CLEMENT <gregory.clement@free-electrons.com>
* Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/init.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/smp.h>
#include <linux/mbus.h>
#include <asm/smp_scu.h>
#include <asm/smp_plat.h>
#include "common.h"
#include "pmsu.h"
#define CRYPT0_ENG_ID 41
#define CRYPT0_ENG_ATTR 0x1
#define SRAM_PHYS_BASE 0xFFFF0000
#define BOOTROM_BASE 0xFFF00000
#define BOOTROM_SIZE 0x100000
extern unsigned char armada_375_smp_cpu1_enable_code_end;
extern unsigned char armada_375_smp_cpu1_enable_code_start;
void armada_375_smp_cpu1_enable_wa(void)
{
void __iomem *sram_virt_base;
mvebu_mbus_del_window(BOOTROM_BASE, BOOTROM_SIZE);
mvebu_mbus_add_window_by_id(CRYPT0_ENG_ID, CRYPT0_ENG_ATTR,
SRAM_PHYS_BASE, SZ_64K);
sram_virt_base = ioremap(SRAM_PHYS_BASE, SZ_64K);
memcpy(sram_virt_base, &armada_375_smp_cpu1_enable_code_start,
&armada_375_smp_cpu1_enable_code_end
- &armada_375_smp_cpu1_enable_code_start);
}
extern void mvebu_cortex_a9_secondary_startup(void);
static int __cpuinit mvebu_cortex_a9_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
int ret, hw_cpu;
pr_info("Booting CPU %d\n", cpu);
/*
* Write the address of secondary startup into the system-wide
* flags register. The boot monitor waits until it receives a
* soft interrupt, and then the secondary CPU branches to this
* address.
*/
hw_cpu = cpu_logical_map(cpu);
if (of_machine_is_compatible("marvell,armada375"))
mvebu_system_controller_set_cpu_boot_addr(mvebu_cortex_a9_secondary_startup);
else
mvebu_pmsu_set_cpu_boot_addr(hw_cpu,
mvebu_cortex_a9_secondary_startup);
smp_wmb();
ret = mvebu_cpu_reset_deassert(hw_cpu);
if (ret) {
pr_err("Could not start the secondary CPU: %d\n", ret);
return ret;
}
arch_send_wakeup_ipi_mask(cpumask_of(cpu));
return 0;
}
static void __init mvebu_cortex_a9_smp_prepare_cpus(unsigned int max_cpus)
{
if (of_machine_is_compatible("marvell,armada375"))
armada_375_smp_cpu1_enable_wa();
}
static struct smp_operations mvebu_cortex_a9_smp_ops __initdata = {
.smp_prepare_cpus = mvebu_cortex_a9_smp_prepare_cpus,
.smp_boot_secondary = mvebu_cortex_a9_boot_secondary,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = armada_xp_cpu_die,
#endif
};
CPU_METHOD_OF_DECLARE(mvebu_armada_375_smp, "marvell,armada-375-smp",
&mvebu_cortex_a9_smp_ops);
CPU_METHOD_OF_DECLARE(mvebu_armada_380_smp, "marvell,armada-380-smp",
&mvebu_cortex_a9_smp_ops);