RE: [PATCH 4/4] ARM: mmp: add SMP support for pxa988

From: Neil Zhang
Date: Mon Apr 15 2013 - 07:29:08 EST





> -----Original Message-----
> From: Haojian Zhuang [mailto:haojian.zhuang@xxxxxxxxx]
> Sent: 2013年4月13日 21:08
> To: Neil Zhang
> Cc: Grant Likely; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx; Chao Xie
> Subject: Re: [PATCH 4/4] ARM: mmp: add SMP support for pxa988
>
> On Thu, Apr 11, 2013 at 11:39 AM, Neil Zhang <zhangwm@xxxxxxxxxxx>
> wrote:
> > Add SMP support for pxa988.
> >
> > Signed-off-by: Neil Zhang <zhangwm@xxxxxxxxxxx>
> > Signed-off-by: Chao Xie <chao.xie@xxxxxxxxxxx>
> > ---
> > arch/arm/mach-mmp/Makefile | 4 +
> > arch/arm/mach-mmp/common.h | 2 +
> > arch/arm/mach-mmp/headsmp.S | 104
> ++++++++++++++++++++++++++
> > arch/arm/mach-mmp/mmpx-dt.c | 1 +
> > arch/arm/mach-mmp/platsmp.c | 170
> +++++++++++++++++++++++++++++++++++++++++++
> > arch/arm/mach-mmp/reset.c | 66 +++++++++++++++++
> > arch/arm/mach-mmp/reset.h | 29 +++++++
> > 7 files changed, 376 insertions(+), 0 deletions(-) create mode
> > 100644 arch/arm/mach-mmp/headsmp.S create mode 100644
> > arch/arm/mach-mmp/platsmp.c create mode 100644
> > arch/arm/mach-mmp/reset.c create mode 100644
> > arch/arm/mach-mmp/reset.h
> >
> > diff --git a/arch/arm/mach-mmp/Makefile
> b/arch/arm/mach-mmp/Makefile
> > index b60065f..e7b6173 100644
> > --- a/arch/arm/mach-mmp/Makefile
> > +++ b/arch/arm/mach-mmp/Makefile
> > @@ -9,6 +9,10 @@ obj-$(CONFIG_CPU_PXA168) += pxa168.o
> > obj-$(CONFIG_CPU_PXA910) += pxa910.o
> > obj-$(CONFIG_CPU_MMP2) += mmp2.o sram.o
> >
> > +ifeq ($(CONFIG_SMP),y)
> > +obj-$(CONFIG_CPU_PXA988) += platsmp.o headsmp.o reset.o
> > +endif
> > +
> You already select CONFIG_SMP if PXA988 is selected. There's no reason to
> check CONFIG_SMP in Makefile again.

CPU_PXA988 only select HAVE_SMP, we can still not enable SMP.


>
> > ifeq ($(CONFIG_COMMON_CLK), )
> > obj-y += clock.o
> > obj-$(CONFIG_CPU_PXA168) += clock-pxa168.o
> > diff --git a/arch/arm/mach-mmp/common.h
> b/arch/arm/mach-mmp/common.h
> > index 8c9b510..7496cd0 100644
> > --- a/arch/arm/mach-mmp/common.h
> > +++ b/arch/arm/mach-mmp/common.h
> > @@ -1,5 +1,7 @@
> > #define ARRAY_AND_SIZE(x) (x), ARRAY_SIZE(x)
> >
> > +extern struct smp_operations mmp_smp_ops;
> > +
> > extern void timer_init(int irq);
> >
> > extern void __init icu_init_irq(void); diff --git
> > a/arch/arm/mach-mmp/headsmp.S b/arch/arm/mach-mmp/headsmp.S
> new file
> > mode 100644 index 0000000..2b6177e
> > --- /dev/null
> > +++ b/arch/arm/mach-mmp/headsmp.S
> > @@ -0,0 +1,104 @@
> > +/*
> > + * linux/arch/arm/mach-mmp/headsmp.S
> > + *
> > + * Copyright (C) 2012 Marvell, Inc.
> > + *
> > + * Author: Neil Zhang <zhangwm@xxxxxxxxxxx>
> > + *
> > + * 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/linkage.h>
> > +#include <linux/init.h>
> > +#include <asm/memory.h>
> > +#include <asm/cache.h>
> > +#include <asm/assembler.h>
> > +#include <mach/addr-map.h>
> > +
> > + __CPUINIT
> > +
> > +/*
> > + * Marvell specific entry point for secondary CPUs.
> > + * The secondary kernel init calls v7_flush_dcache_all before it
> > +enables
> > + * the L1; however, the L1 comes out of reset in an undefined state,
> > +so
> > + * the clean + invalidate performed by v7_flush_dcache_all causes a
> > +bunch
> > + * of cache lines with uninitialized data and uninitialized tags to
> > +get
> > + * written out to memory, which does really unpleasant things to the
> > +main
> > + * processor. We fix this by performing an invalidate, rather than a
> > + * clean + invalidate for secondary core, before jumping into the kernel.
> > + *
> > + * This funciton is cloned from arch/arm/mach-tegra/headsmp.S, and
> > +needs
> > + * to be called for both secondary cores startup and primary core
> > +resume
> > + * procedures.
> > + */
> > + .align L1_CACHE_SHIFT
> > +
> > +
> > +/*
> > + * PXA specific entry point for secondary CPUs. This provides
> > + * a "holding pen" into which all secondary cores are held until
> > +we're
> > + * ready for them to initialise.
> > + */
> > +ENTRY(mmp_secondary_startup)
> > + mrc p15, 0, r0, c0, c0, 5
> > + and r0, r0, #15
> > + adr r4, 1f
> > + ldmia r4, {r5, r6}
> > + sub r4, r4, r5
> > + add r6, r6, r4
> > +pen: ldr r7, [r6]
> > + cmp r7, r0
> > + bne pen
> > +
> > + /*
> > + * we've been released from the holding pen: secondary_stack
> > + * should now contain the SVC stack for this core
> > + */
> > + bl v7_invalidate_l1
> > + b secondary_startup
> > +ENDPROC(mmp_secondary_startup)
> > +
> > + .align 2
> > +1: .long .
> > + .long pen_release
> > +
> > +
> > +/*
> > + * Note: The following code is located into the .data section. This is to
> > + * allow sw_reset_flag and cpu_plugin_handler to be accessed
> with a
> > + * relative load while we can't rely on any MMU translation.
> > + * Reference from: arch/arm/kernel/sleep.S
> > + */
> > +
> > + .data
> > + .align
> > +
> > +/*
> > + * ROM code jumps to this function while waking up from CPU
> > + * OFF or software reset state. Physical address of the function is
> > + * stored at CA9_WARM_RESET_VECTOR while system is bring up.
> > + */
> > +ENTRY(mmp_cpu_reset_entry)
> > + adr r1, mmp_entry_vectors
> > + mrc p15, 0, r0, c0, c0, 5
> > + and r0, r0, #15 @ fetch CPUID
> > +1:
> > + ldr r2, [r1, r0, lsl #2] @ get the handler addr for this
> core
> > + cmp r2, #0
> > + movne pc, r2 @ jump to the handler
> > + beq 1b
> > +ENDPROC(mmp_cpu_reset_entry)
> > +
> > + /* Point to the address that save handlers for each core */
> > + .global mmp_entry_vectors
> > +mmp_entry_vectors:
> > + .rept CONFIG_NR_CPUS
> > + .long 0 @ preserve
> stack phys ptr here
> > + .endr
> > diff --git a/arch/arm/mach-mmp/mmpx-dt.c
> b/arch/arm/mach-mmp/mmpx-dt.c
> > index bbc0c50..a5f5501 100644
> > --- a/arch/arm/mach-mmp/mmpx-dt.c
> > +++ b/arch/arm/mach-mmp/mmpx-dt.c
> > @@ -71,6 +71,7 @@ static const char *pxa988_dt_board_compat[]
> > __initdata = { };
> >
> > DT_MACHINE_START(PXA988_DT, "Marvell PXA988 (Device Tree
> Support)")
> > + .smp = smp_ops(mmp_smp_ops),
> > .map_io = mmp_map_io,
> > .init_irq = pxa988_dt_gic_init,
> > .init_time = pxa988_dt_init_timer,
> > diff --git a/arch/arm/mach-mmp/platsmp.c
> b/arch/arm/mach-mmp/platsmp.c
> > new file mode 100644 index 0000000..a6590a3
> > --- /dev/null
> > +++ b/arch/arm/mach-mmp/platsmp.c
> > @@ -0,0 +1,170 @@
> > +/*
> > + * linux/arch/arm/mach-mmp/platsmp.c
> > + *
> > + * Copyright (C) 2002 ARM Ltd.
> > + * All Rights Reserved
> > + *
> > + * 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/init.h>
> > +#include <linux/errno.h>
> > +#include <linux/delay.h>
> > +#include <linux/device.h>
> > +#include <linux/jiffies.h>
> > +#include <linux/smp.h>
> > +#include <linux/io.h>
> > +#include <linux/irq.h>
> > +
> > +#include <asm/cacheflush.h>
> > +#include <mach/hardware.h>
> > +#include <linux/irqchip/arm-gic.h>
> > +#include <asm/mach-types.h>
> > +#include <asm/localtimer.h>
> > +#include <asm/smp_scu.h>
> > +
> > +#include <mach/irqs.h>
> > +#include <mach/addr-map.h>
> > +
> > +#include "common.h"
> > +#include "reset.h"
> > +
> > +/*
> > + * Write pen_release in a way that is guaranteed to be visible to all
> > + * observers, irrespective of whether they're taking part in
> > +coherency
> > + * or not. This is necessary for the hotplug code to work reliably.
> > + */
> > +static void __cpuinit write_pen_release(int val) {
> > + pen_release = val;
> > + smp_wmb();
> > + __cpuc_flush_dcache_area((void *)&pen_release,
> sizeof(pen_release));
> > + outer_clean_range(__pa(&pen_release), __pa(&pen_release +
> 1));
> > +}
> > +
> > +#ifdef CONFIG_HAVE_ARM_SCU
> > +static void __iomem *scu_get_base_addr(void) {
> > + return SCU_VIRT_BASE;
> > +}
> > +#endif
> > +
> > +static inline unsigned int get_core_count(void) {
> > + u32 ret = 1;
> > +#ifdef CONFIG_HAVE_ARM_SCU
> > + ret = scu_get_core_count(scu_get_base_addr());
> > +#endif
> > +
> > + return ret;
> > +}
> > +
> > +static DEFINE_SPINLOCK(boot_lock);
> > +
> > +static void __cpuinit mmp_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);
> > +
> > + /*
> > + * let the primary processor know we're out of the
> > + * pen, then head off into the C entry point
> > + */
> > + write_pen_release(-1);
> > +
> > + /*
> > + * Synchronise with the boot thread.
> > + */
> > + spin_lock(&boot_lock);
> > + spin_unlock(&boot_lock);
> Lock & unlock without protecting anything. If so, you can remove this.
>
> > +}
> > +
> > +static int __cpuinit mmp_boot_secondary(unsigned int cpu, struct
> > +task_struct *idle) {
> > + unsigned long timeout;
> > +
> > + /*
> > + * Avoid timer calibration on slave cpus. Use the value calibrated
> > + * on master cpu. Referenced from tegra3
> > + */
> > + preset_lpj = loops_per_jiffy;
> > +
> > + /*
> > + * set synchronisation state between this boot processor
> > + * and the secondary one
> > + */
> > +
> > + spin_lock(&boot_lock);
> > +
> > + /*
> > + * The secondary processor is waiting to be released from
> > + * the holding pen - release it, then wait for it to flag
> > + * that it has been released by resetting pen_release.
> > + *
> > + * Note that "pen_release" is the hardware CPU ID, whereas
> > + * "cpu" is Linux's internal ID.
> > + */
> > + write_pen_release(cpu);
> > +
> > + /* reset the cpu, let it branch to the kernel entry */
> > + mmp_cpu_power_up(cpu);
> > +
> > + timeout = jiffies + (1 * HZ);
> > + while (time_before(jiffies, timeout)) {
> > + smp_rmb();
> > + if (pen_release == -1)
> > + break;
> > +
> > + udelay(10);
> > + }
> > +
> > + /*
> > + * now the secondary core is starting up let it run its
> > + * calibrations, then wait for it to finish
> > + */
> > + spin_unlock(&boot_lock);
> > +
> > + return pen_release != -1 ? -ENOSYS : 0; }
> > +
> > +/*
> > + * Initialise the CPU possible map early - this describes the CPUs
> > + * which may be present or become present in the system.
> > + */
> > +static void __init mmp_smp_init_cpus(void) {
> > + unsigned int i, ncores = get_core_count();
> > +
> > + for (i = 0; i < ncores; i++)
> > + set_cpu_possible(i, true); }
> > +
> > +static void __init mmp_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);
> > +
> > +#ifdef CONFIG_HAVE_ARM_SCU
> > + scu_enable(scu_get_base_addr()); #endif
> > +
> > + mmp_entry_vector_init();
> > +}
> > +
> > +struct smp_operations mmp_smp_ops __initdata = {
> > + .smp_init_cpus = mmp_smp_init_cpus,
> > + .smp_prepare_cpus = mmp_smp_prepare_cpus,
> > + .smp_secondary_init = mmp_secondary_init,
> > + .smp_boot_secondary = mmp_boot_secondary,
> > +};
> > diff --git a/arch/arm/mach-mmp/reset.c b/arch/arm/mach-mmp/reset.c
> new
> > file mode 100644 index 0000000..b47e400
> > --- /dev/null
> > +++ b/arch/arm/mach-mmp/reset.c
> > @@ -0,0 +1,66 @@
> > +/*
> > + * linux/arch/arm/mach-mmp/reset.c
> > + *
> > + * Author: Neil Zhang <zhangwm@xxxxxxxxxxx>
> > + * Copyright: (C) 2012 Marvell International Ltd.
> > + *
> > + * 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.
> > + */
> > +
> > +#include <linux/kernel.h>
> > +#include <linux/smp.h>
> > +
> > +#include <asm/io.h>
> > +#include <asm/cacheflush.h>
> > +#include <asm/mach/map.h>
> > +
> > +#include <mach/addr-map.h>
> > +
> > +#include "reset.h"
> > +
> > +#define PMU_CC2_AP APMU_REG(0x0100)
> > +#define CIU_CA9_WARM_RESET_VECTOR CIU_REG(0x00d8)
> > +
> > +/*
> > + * This function is called from boot_secondary to bootup the secondary
> cpu.
> > + */
> > +void mmp_cpu_power_up(u32 cpu)
> > +{
> > + u32 tmp;
> > +
> > + BUG_ON(cpu == 0);
> > +
> > + tmp = readl(PMU_CC2_AP);
> > + if (tmp & CPU_CORE_RST(cpu)) {
> > + /* Release secondary core from reset */
> > + tmp &= ~(CPU_CORE_RST(cpu)
> > + | CPU_DBG_RST(cpu) |
> CPU_WDOG_RST(cpu));
> > + writel(tmp, PMU_CC2_AP);
> > + }
> > +}
> > +
> > +void mmp_set_entry_vector(u32 cpu, u32 addr) {
> > + BUG_ON(cpu >= CONFIG_NR_CPUS);
> > +
> > + mmp_entry_vectors[cpu] = addr;
> > + smp_wmb();
> > + __cpuc_flush_dcache_area((void *)&mmp_entry_vectors[cpu],
> > + sizeof(mmp_entry_vectors[cpu]));
> > + outer_clean_range(__pa(&mmp_entry_vectors[cpu]),
> > + __pa(&mmp_entry_vectors[cpu +
> 1])); }
> > +
> > +void __init mmp_entry_vector_init(void) {
> > + int cpu;
> > +
> > + /* We will reset from DDR directly by default */
> > + writel(__pa(mmp_cpu_reset_entry),
> CIU_CA9_WARM_RESET_VECTOR);
> > +
> > + for (cpu = 1; cpu < CONFIG_NR_CPUS; cpu++)
> > + mmp_set_entry_vector(cpu,
> > +__pa(mmp_secondary_startup)); }
> > diff --git a/arch/arm/mach-mmp/reset.h b/arch/arm/mach-mmp/reset.h
> new
> > file mode 100644 index 0000000..78d5486
> > --- /dev/null
> > +++ b/arch/arm/mach-mmp/reset.h
> > @@ -0,0 +1,29 @@
> > +/*
> > + * linux/arch/arm/mach-mmp/include/mach/reset.h
> > + *
> > + * Author: Neil Zhang <zhangwm@xxxxxxxxxxx>
> > + * Copyright: (C) 2012 Marvell International Ltd.
> > + *
> > + * 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.
> > + */
> > +
> > +#ifndef __RESET_PXA988_H__
> > +#define __RESET_PXA988_H__
> > +
> > +#define CPU_CORE_RST(n) (1 << ((n) * 4 + 16))
> > +#define CPU_DBG_RST(n) (1 << ((n) * 4 + 18))
> > +#define CPU_WDOG_RST(n) (1 << ((n) * 4 + 19))
> > +
> > +extern u32 mmp_entry_vectors[CONFIG_NR_CPUS];
> > +
> > +void mmp_secondary_startup(void);
> > +void mmp_cpu_reset_entry(void);
> > +
> > +void mmp_cpu_power_up(u32 cpu);
> > +void mmp_set_entry_vector(u32 cpu, u32 addr); void __init
> > +mmp_entry_vector_init(void);
> > +
> > +#endif /* __RESET_PXA988_H__ */
> > --
> > 1.7.4.1
> >


Best Regards,
Neil Zhang
韬{.n?????%?lzwm?b?Р骒r?zXЩ??{ay????j?f"?????ア?⒎?:+v???????赙zZ+????"?!?O???v??m?鹈 n?帼Y&