linux_dsm_epyc7002/arch/arm/mach-zynq/platsmp.c
Quanyang Wang 6c6b3f1f26 ARM: zynq: use physical cpuid in zynq_slcr_cpu_stop/start
When kernel booting, it will create a cpuid map between the logical cpus
and physical cpus. In a normal boot, the cpuid map is as below:

    Physical      Logical
        0    ==>     0
        1    ==>     1

But in kdump, there is a condition that the crash happens at the
physical cpu1, and the crash kernel will run at the physical cpu1 too,
so the cpuid map in crash kernel is as below:

    Physical      Logical
        1    ==>     0
        0    ==>     1

The functions zynq_slcr_cpu_stop/start is to stop/start the physical
cpus, the parameter cpu should be the physical cpuid. So use
cpu_logical_map to translate the logical cpuid to physical cpuid.
Or else the logical cpu0(physical cpu1) will stop itself and
the processor will hang.

Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>
Tested-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
2020-01-08 15:21:09 +01:00

164 lines
3.9 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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.
*/
#include <linux/export.h>
#include <linux/jiffies.h>
#include <linux/init.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.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 not in __init section.
*/
static int ncores;
int zynq_cpun_start(u32 address, int cpu)
{
u32 trampoline_code_size = &zynq_secondary_trampoline_end -
&zynq_secondary_trampoline;
u32 phy_cpuid = cpu_logical_map(cpu);
/* 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(phy_cpuid);
if (address) {
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_toio(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(phy_cpuid);
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 zynq_boot_secondary(unsigned int cpu, struct task_struct *idle)
{
return zynq_cpun_start(__pa_symbol(secondary_startup_arm), 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)
{
scu_enable(zynq_scu_base);
}
/**
* zynq_secondary_init - Initialize secondary CPU cores
* @cpu: CPU that is initialized
*
* This function is in the hotplug path. Don't move it into the
* init section!!
*/
static void zynq_secondary_init(unsigned int cpu)
{
zynq_core_pm_init();
}
#ifdef CONFIG_HOTPLUG_CPU
static int zynq_cpu_kill(unsigned cpu)
{
unsigned long timeout = jiffies + msecs_to_jiffies(50);
while (zynq_slcr_cpu_state_read(cpu))
if (time_after(jiffies, timeout))
return 0;
zynq_slcr_cpu_stop(cpu);
return 1;
}
/**
* zynq_cpu_die - Let a CPU core die
* @cpu: Dying CPU
*
* Platform-specific code to shutdown a CPU.
* Called with IRQs disabled on the dying CPU.
*/
static void zynq_cpu_die(unsigned int cpu)
{
zynq_slcr_cpu_state_write(cpu, true);
/*
* there is no power-control hardware on this platform, so all
* we can do is put the core into WFI; this is safe as the calling
* code will have already disabled interrupts
*/
for (;;)
cpu_do_idle();
}
#endif
const struct smp_operations zynq_smp_ops __initconst = {
.smp_init_cpus = zynq_smp_init_cpus,
.smp_prepare_cpus = zynq_smp_prepare_cpus,
.smp_boot_secondary = zynq_boot_secondary,
.smp_secondary_init = zynq_secondary_init,
#ifdef CONFIG_HOTPLUG_CPU
.cpu_die = zynq_cpu_die,
.cpu_kill = zynq_cpu_kill,
#endif
};