arm: zynq: Add smp support

Zynq is dual core Cortex A9 which starts always
at zero. Using simple trampoline ensure long jump
to secondary_startup code.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
This commit is contained in:
Michal Simek 2013-03-20 13:50:12 +01:00
parent 2f34e0a58f
commit aa7eb2bb4e
7 changed files with 216 additions and 0 deletions

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@ -8,6 +8,7 @@ config ARCH_ZYNQ
select ICST
select MIGHT_HAVE_CACHE_L2X0
select USE_OF
select HAVE_SMP
select SPARSE_IRQ
select CADENCE_TTC_TIMER
help

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@ -4,3 +4,4 @@
# Common support
obj-y := common.o slcr.o
obj-$(CONFIG_SMP) += headsmp.o platsmp.o

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@ -104,6 +104,7 @@ static const char * const zynq_dt_match[] = {
};
MACHINE_START(XILINX_EP107, "Xilinx Zynq Platform")
.smp = smp_ops(zynq_smp_ops),
.map_io = zynq_map_io,
.init_irq = irqchip_init,
.init_machine = zynq_init_machine,

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@ -19,6 +19,17 @@
extern int zynq_slcr_init(void);
extern void zynq_slcr_system_reset(void);
extern void zynq_slcr_cpu_stop(int cpu);
extern void zynq_slcr_cpu_start(int cpu);
#ifdef CONFIG_SMP
extern void secondary_startup(void);
extern char zynq_secondary_trampoline;
extern char zynq_secondary_trampoline_jump;
extern char zynq_secondary_trampoline_end;
extern int __cpuinit zynq_cpun_start(u32 address, int cpu);
extern struct smp_operations zynq_smp_ops __initdata;
#endif
extern void __iomem *zynq_slcr_base;
extern void __iomem *zynq_scu_base;

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@ -0,0 +1,24 @@
/*
* Copyright (c) 2013 Steffen Trumtrar <s.trumtrar@pengutronix.de>
* Copyright (c) 2012-2013 Xilinx
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <linux/init.h>
__CPUINIT
ENTRY(zynq_secondary_trampoline)
ldr r0, [pc]
bx r0
.globl zynq_secondary_trampoline_jump
zynq_secondary_trampoline_jump:
/* Space for jumping address */
.word /* cpu 1 */
.globl zynq_secondary_trampoline_end
zynq_secondary_trampoline_end:
ENDPROC(zynq_secondary_trampoline)

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@ -0,0 +1,149 @@
/*
* This file contains Xilinx specific SMP code, used to start up
* the second processor.
*
* Copyright (C) 2011-2013 Xilinx
*
* based on linux/arch/arm/mach-realview/platsmp.c
*
* Copyright (C) 2002 ARM Ltd.
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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/export.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/smp_scu.h>
#include <linux/irqchip/arm-gic.h>
#include "common.h"
/*
* Store number of cores in the system
* Because of scu_get_core_count() must be in __init section and can't
* be called from zynq_cpun_start() because it is in __cpuinit section.
*/
static int ncores;
/* Secondary CPU kernel startup is a 2 step process. The primary CPU
* starts the secondary CPU by giving it the address of the kernel and
* then sending it an event to wake it up. The secondary CPU then
* starts the kernel and tells the primary CPU it's up and running.
*/
static void __cpuinit zynq_secondary_init(unsigned int cpu)
{
/*
* if any interrupts are already enabled for the primary
* core (e.g. timer irq), then they will not have been enabled
* for us: do so
*/
gic_secondary_init(0);
}
int __cpuinit zynq_cpun_start(u32 address, int cpu)
{
u32 trampoline_code_size = &zynq_secondary_trampoline_end -
&zynq_secondary_trampoline;
if (cpu > ncores) {
pr_warn("CPU No. is not available in the system\n");
return -1;
}
/* MS: Expectation that SLCR are directly map and accessible */
/* Not possible to jump to non aligned address */
if (!(address & 3) && (!address || (address >= trampoline_code_size))) {
/* Store pointer to ioremap area which points to address 0x0 */
static u8 __iomem *zero;
u32 trampoline_size = &zynq_secondary_trampoline_jump -
&zynq_secondary_trampoline;
zynq_slcr_cpu_stop(cpu);
if (__pa(PAGE_OFFSET)) {
zero = ioremap(0, trampoline_code_size);
if (!zero) {
pr_warn("BOOTUP jump vectors not accessible\n");
return -1;
}
} else {
zero = (__force u8 __iomem *)PAGE_OFFSET;
}
/*
* This is elegant way how to jump to any address
* 0x0: Load address at 0x8 to r0
* 0x4: Jump by mov instruction
* 0x8: Jumping address
*/
memcpy((__force void *)zero, &zynq_secondary_trampoline,
trampoline_size);
writel(address, zero + trampoline_size);
flush_cache_all();
outer_flush_range(0, trampoline_code_size);
smp_wmb();
if (__pa(PAGE_OFFSET))
iounmap(zero);
zynq_slcr_cpu_start(cpu);
return 0;
}
pr_warn("Can't start CPU%d: Wrong starting address %x\n", cpu, address);
return -1;
}
EXPORT_SYMBOL(zynq_cpun_start);
static int __cpuinit zynq_boot_secondary(unsigned int cpu,
struct task_struct *idle)
{
return zynq_cpun_start(virt_to_phys(secondary_startup), cpu);
}
/*
* Initialise the CPU possible map early - this describes the CPUs
* which may be present or become present in the system.
*/
static void __init zynq_smp_init_cpus(void)
{
int i;
ncores = scu_get_core_count(zynq_scu_base);
for (i = 0; i < ncores && i < CONFIG_NR_CPUS; i++)
set_cpu_possible(i, true);
}
static void __init zynq_smp_prepare_cpus(unsigned int max_cpus)
{
int i;
/*
* Initialise the present map, which describes the set of CPUs
* actually populated at the present time.
*/
for (i = 0; i < max_cpus; i++)
set_cpu_present(i, true);
scu_enable(zynq_scu_base);
}
struct smp_operations zynq_smp_ops __initdata = {
.smp_init_cpus = zynq_smp_init_cpus,
.smp_prepare_cpus = zynq_smp_prepare_cpus,
.smp_secondary_init = zynq_secondary_init,
.smp_boot_secondary = zynq_boot_secondary,
};

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@ -33,6 +33,11 @@
#define SLCR_UNLOCK 0x8 /* SCLR unlock register */
#define SLCR_PS_RST_CTRL_OFFSET 0x200 /* PS Software Reset Control */
#define SLCR_A9_CPU_CLKSTOP 0x10
#define SLCR_A9_CPU_RST 0x1
#define SLCR_A9_CPU_RST_CTRL 0x244 /* CPU Software Reset Control */
#define SLCR_REBOOT_STATUS 0x258 /* PS Reboot Status */
void __iomem *zynq_slcr_base;
@ -61,6 +66,30 @@ void zynq_slcr_system_reset(void)
writel(1, zynq_slcr_base + SLCR_PS_RST_CTRL_OFFSET);
}
/**
* zynq_slcr_cpu_start - Start cpu
* @cpu: cpu number
*/
void zynq_slcr_cpu_start(int cpu)
{
/* enable CPUn */
writel(SLCR_A9_CPU_CLKSTOP << cpu,
zynq_slcr_base + SLCR_A9_CPU_RST_CTRL);
/* enable CLK for CPUn */
writel(0x0 << cpu, zynq_slcr_base + SLCR_A9_CPU_RST_CTRL);
}
/**
* zynq_slcr_cpu_stop - Stop cpu
* @cpu: cpu number
*/
void zynq_slcr_cpu_stop(int cpu)
{
/* stop CLK and reset CPUn */
writel((SLCR_A9_CPU_CLKSTOP | SLCR_A9_CPU_RST) << cpu,
zynq_slcr_base + SLCR_A9_CPU_RST_CTRL);
}
/**
* zynq_slcr_init
* Returns 0 on success, negative errno otherwise.