[PATCH v7 2/5] powerpc/85xx: add HOTPLUG_CPU support
Kumar Gala
galak at kernel.crashing.org
Fri Jul 13 22:15:06 EST 2012
On Jul 3, 2012, at 5:21 AM, Zhao Chenhui wrote:
> From: Li Yang <leoli at freescale.com>
>
> Add support to disable and re-enable individual cores at runtime
> on MPC85xx/QorIQ SMP machines. Currently support e500v1/e500v2 core.
>
> MPC85xx machines use ePAPR spin-table in boot page for CPU kick-off.
> This patch uses the boot page from bootloader to boot core at runtime.
> It supports 32-bit and 36-bit physical address.
>
> Add generic_set_cpu_up() to set cpu_state as CPU_UP_PREPARE in kick_cpu().
Shouldn't the generic_setup_cpu_up() be a separate patch, and refactor smp_generic_kick_cpu() to use it.
Also, we should pull the conversion of the spintable from #defines to struct into a separate patch before this one.
>
> Signed-off-by: Li Yang <leoli at freescale.com>
> Signed-off-by: Jin Qing <b24347 at freescale.com>
> Signed-off-by: Zhao Chenhui <chenhui.zhao at freescale.com>
> ---
> v7:
> * removed CONFIG_85xx_TB_SYNC
> no change to the rest of the patch set
>
> arch/powerpc/Kconfig | 6 +-
> arch/powerpc/include/asm/cacheflush.h | 2 +
> arch/powerpc/include/asm/smp.h | 2 +
> arch/powerpc/kernel/head_fsl_booke.S | 28 +++++++
> arch/powerpc/kernel/smp.c | 10 +++
> arch/powerpc/platforms/85xx/smp.c | 137 ++++++++++++++++++++++++---------
> 6 files changed, 146 insertions(+), 39 deletions(-)
>
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index 38786c8..d6bacbe 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -220,7 +220,8 @@ config ARCH_HIBERNATION_POSSIBLE
> config ARCH_SUSPEND_POSSIBLE
> def_bool y
> depends on ADB_PMU || PPC_EFIKA || PPC_LITE5200 || PPC_83xx || \
> - (PPC_85xx && !SMP) || PPC_86xx || PPC_PSERIES || 44x || 40x
> + (PPC_85xx && !PPC_E500MC) || PPC_86xx || PPC_PSERIES \
> + || 44x || 40x
>
> config PPC_DCR_NATIVE
> bool
> @@ -331,7 +332,8 @@ config SWIOTLB
>
> config HOTPLUG_CPU
> bool "Support for enabling/disabling CPUs"
> - depends on SMP && HOTPLUG && EXPERIMENTAL && (PPC_PSERIES || PPC_PMAC || PPC_POWERNV)
> + depends on SMP && HOTPLUG && EXPERIMENTAL && (PPC_PSERIES || \
> + PPC_PMAC || PPC_POWERNV || (PPC_85xx && !PPC_E500MC))
> ---help---
> Say Y here to be able to disable and re-enable individual
> CPUs at runtime on SMP machines.
> diff --git a/arch/powerpc/include/asm/cacheflush.h b/arch/powerpc/include/asm/cacheflush.h
> index ab9e402..b843e35 100644
> --- a/arch/powerpc/include/asm/cacheflush.h
> +++ b/arch/powerpc/include/asm/cacheflush.h
> @@ -30,6 +30,8 @@ extern void flush_dcache_page(struct page *page);
> #define flush_dcache_mmap_lock(mapping) do { } while (0)
> #define flush_dcache_mmap_unlock(mapping) do { } while (0)
>
> +extern void __flush_disable_L1(void);
> +
> extern void __flush_icache_range(unsigned long, unsigned long);
> static inline void flush_icache_range(unsigned long start, unsigned long stop)
> {
> diff --git a/arch/powerpc/include/asm/smp.h b/arch/powerpc/include/asm/smp.h
> index ebc24dc..e807e9d 100644
> --- a/arch/powerpc/include/asm/smp.h
> +++ b/arch/powerpc/include/asm/smp.h
> @@ -65,6 +65,7 @@ int generic_cpu_disable(void);
> void generic_cpu_die(unsigned int cpu);
> void generic_mach_cpu_die(void);
> void generic_set_cpu_dead(unsigned int cpu);
> +void generic_set_cpu_up(unsigned int cpu);
> int generic_check_cpu_restart(unsigned int cpu);
> #endif
>
> @@ -190,6 +191,7 @@ extern unsigned long __secondary_hold_spinloop;
> extern unsigned long __secondary_hold_acknowledge;
> extern char __secondary_hold;
>
> +extern void __early_start(void);
> #endif /* __ASSEMBLY__ */
>
> #endif /* __KERNEL__ */
> diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
> index de80e0f..be0261b 100644
> --- a/arch/powerpc/kernel/head_fsl_booke.S
> +++ b/arch/powerpc/kernel/head_fsl_booke.S
> @@ -996,6 +996,34 @@ _GLOBAL(flush_dcache_L1)
>
> blr
>
> +/* Flush L1 d-cache, invalidate and disable d-cache and i-cache */
> +_GLOBAL(__flush_disable_L1)
> + mflr r10
> + bl flush_dcache_L1 /* Flush L1 d-cache */
> + mtlr r10
> +
> + mfspr r4, SPRN_L1CSR0 /* Invalidate and disable d-cache */
> + li r5, 2
> + rlwimi r4, r5, 0, 3
> +
> + msync
> + isync
> + mtspr SPRN_L1CSR0, r4
> + isync
> +
> +1: mfspr r4, SPRN_L1CSR0 /* Wait for the invalidate to finish */
> + andi. r4, r4, 2
> + bne 1b
> +
> + mfspr r4, SPRN_L1CSR1 /* Invalidate and disable i-cache */
> + li r5, 2
> + rlwimi r4, r5, 0, 3
> +
> + mtspr SPRN_L1CSR1, r4
> + isync
> +
> + blr
> +
> #ifdef CONFIG_SMP
> /* When we get here, r24 needs to hold the CPU # */
> .globl __secondary_start
> diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
> index d9f9441..e0ffe03 100644
> --- a/arch/powerpc/kernel/smp.c
> +++ b/arch/powerpc/kernel/smp.c
> @@ -423,6 +423,16 @@ void generic_set_cpu_dead(unsigned int cpu)
> per_cpu(cpu_state, cpu) = CPU_DEAD;
> }
>
> +/*
> + * The cpu_state should be set to CPU_UP_PREPARE in kick_cpu(), otherwise
> + * the cpu_state is always CPU_DEAD after calling generic_set_cpu_dead(),
> + * which makes the delay in generic_cpu_die() not happen.
> + */
> +void generic_set_cpu_up(unsigned int cpu)
> +{
> + per_cpu(cpu_state, cpu) = CPU_UP_PREPARE;
> +}
> +
> int generic_check_cpu_restart(unsigned int cpu)
> {
> return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
> diff --git a/arch/powerpc/platforms/85xx/smp.c b/arch/powerpc/platforms/85xx/smp.c
> index 2e65fe8..925e678 100644
> --- a/arch/powerpc/platforms/85xx/smp.c
> +++ b/arch/powerpc/platforms/85xx/smp.c
> @@ -2,7 +2,7 @@
> * Author: Andy Fleming <afleming at freescale.com>
> * Kumar Gala <galak at kernel.crashing.org>
> *
> - * Copyright 2006-2008, 2011 Freescale Semiconductor Inc.
> + * Copyright 2006-2008, 2011-2012 Freescale Semiconductor Inc.
> *
> * 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
> @@ -17,6 +17,7 @@
> #include <linux/of.h>
> #include <linux/kexec.h>
> #include <linux/highmem.h>
> +#include <linux/cpu.h>
>
> #include <asm/machdep.h>
> #include <asm/pgtable.h>
> @@ -30,18 +31,14 @@
> #include <sysdev/mpic.h>
> #include "smp.h"
>
> -extern void __early_start(void);
> -
> -#define BOOT_ENTRY_ADDR_UPPER 0
> -#define BOOT_ENTRY_ADDR_LOWER 1
> -#define BOOT_ENTRY_R3_UPPER 2
> -#define BOOT_ENTRY_R3_LOWER 3
> -#define BOOT_ENTRY_RESV 4
> -#define BOOT_ENTRY_PIR 5
> -#define BOOT_ENTRY_R6_UPPER 6
> -#define BOOT_ENTRY_R6_LOWER 7
> -#define NUM_BOOT_ENTRY 8
> -#define SIZE_BOOT_ENTRY (NUM_BOOT_ENTRY * sizeof(u32))
> +struct epapr_spin_table {
> + u32 addr_h;
> + u32 addr_l;
> + u32 r3_h;
> + u32 r3_l;
> + u32 reserved;
> + u32 pir;
> +};
>
> static struct ccsr_guts __iomem *guts;
> static u64 timebase;
> @@ -101,15 +98,45 @@ static void mpc85xx_take_timebase(void)
> local_irq_restore(flags);
> }
>
> -static int __init
> -smp_85xx_kick_cpu(int nr)
> +#ifdef CONFIG_HOTPLUG_CPU
> +static void __cpuinit smp_85xx_mach_cpu_die(void)
> +{
> + unsigned int cpu = smp_processor_id();
> + u32 tmp;
> +
> + local_irq_disable();
> + idle_task_exit();
> + generic_set_cpu_dead(cpu);
> + mb();
> +
> + mtspr(SPRN_TCR, 0);
> +
> + __flush_disable_L1();
> + tmp = (mfspr(SPRN_HID0) & ~(HID0_DOZE|HID0_SLEEP)) | HID0_NAP;
> + mtspr(SPRN_HID0, tmp);
> + isync();
> +
> + /* Enter NAP mode. */
> + tmp = mfmsr();
> + tmp |= MSR_WE;
> + mb();
> + mtmsr(tmp);
> + isync();
> +
> + while (1)
> + ;
> +}
> +#endif
> +
> +static int __cpuinit smp_85xx_kick_cpu(int nr)
> {
> unsigned long flags;
> const u64 *cpu_rel_addr;
> - __iomem u32 *bptr_vaddr;
> + __iomem struct epapr_spin_table *spin_table;
> struct device_node *np;
> - int n = 0, hw_cpu = get_hard_smp_processor_id(nr);
> + int hw_cpu = get_hard_smp_processor_id(nr);
> int ioremappable;
> + int ret = 0;
>
> WARN_ON(nr < 0 || nr >= NR_CPUS);
> WARN_ON(hw_cpu < 0 || hw_cpu >= NR_CPUS);
> @@ -134,46 +161,80 @@ smp_85xx_kick_cpu(int nr)
>
> /* Map the spin table */
> if (ioremappable)
> - bptr_vaddr = ioremap(*cpu_rel_addr, SIZE_BOOT_ENTRY);
> + spin_table = ioremap(*cpu_rel_addr,
> + sizeof(struct epapr_spin_table));
> else
> - bptr_vaddr = phys_to_virt(*cpu_rel_addr);
> + spin_table = phys_to_virt(*cpu_rel_addr);
>
> local_irq_save(flags);
> -
> - out_be32(bptr_vaddr + BOOT_ENTRY_PIR, hw_cpu);
> #ifdef CONFIG_PPC32
> - out_be32(bptr_vaddr + BOOT_ENTRY_ADDR_LOWER, __pa(__early_start));
> +#ifdef CONFIG_HOTPLUG_CPU
> + /* Corresponding to generic_set_cpu_dead() */
> + generic_set_cpu_up(nr);
> +
> + if (system_state == SYSTEM_RUNNING) {
> + out_be32(&spin_table->addr_l, 0);
> +
> + /*
> + * We don't set the BPTR register here since it already points
> + * to the boot page properly.
> + */
> + mpic_reset_core(hw_cpu);
> +
> + /* wait until core is ready... */
> + if (!spin_event_timeout(in_be32(&spin_table->addr_l) == 1,
> + 10000, 100)) {
> + pr_err("%s: timeout waiting for core %d to reset\n",
> + __func__, hw_cpu);
> + ret = -ENOENT;
> + goto out;
> + }
> +
> + /* clear the acknowledge status */
> + __secondary_hold_acknowledge = -1;
> + }
> +#endif
> + out_be32(&spin_table->pir, hw_cpu);
> + out_be32(&spin_table->addr_l, __pa(__early_start));
>
> if (!ioremappable)
> - flush_dcache_range((ulong)bptr_vaddr,
> - (ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
> + flush_dcache_range((ulong)spin_table,
> + (ulong)spin_table + sizeof(struct epapr_spin_table));
>
> /* Wait a bit for the CPU to ack. */
> - while ((__secondary_hold_acknowledge != hw_cpu) && (++n < 1000))
> - mdelay(1);
> + if (!spin_event_timeout(__secondary_hold_acknowledge == hw_cpu,
> + 10000, 100)) {
> + pr_err("%s: timeout waiting for core %d to ack\n",
> + __func__, hw_cpu);
> + ret = -ENOENT;
> + goto out;
> + }
> +out:
> #else
> smp_generic_kick_cpu(nr);
>
> - out_be64((u64 *)(bptr_vaddr + BOOT_ENTRY_ADDR_UPPER),
> - __pa((u64)*((unsigned long long *) generic_secondary_smp_init)));
> + out_be32(&spin_table->pir, hw_cpu);
> + out_be64((u64 *)(&spin_table->addr_h),
> + __pa((u64)*((unsigned long long *)generic_secondary_smp_init)));
>
> if (!ioremappable)
> - flush_dcache_range((ulong)bptr_vaddr,
> - (ulong)(bptr_vaddr + SIZE_BOOT_ENTRY));
> + flush_dcache_range((ulong)spin_table,
> + (ulong)spin_table + sizeof(struct epapr_spin_table));
> #endif
> -
> local_irq_restore(flags);
>
> if (ioremappable)
> - iounmap(bptr_vaddr);
> + iounmap(spin_table);
>
> - pr_debug("waited %d msecs for CPU #%d.\n", n, nr);
> -
> - return 0;
> + return ret;
> }
>
> struct smp_ops_t smp_85xx_ops = {
> .kick_cpu = smp_85xx_kick_cpu,
> +#ifdef CONFIG_HOTPLUG_CPU
> + .cpu_disable = generic_cpu_disable,
> + .cpu_die = generic_cpu_die,
> +#endif
> #ifdef CONFIG_KEXEC
> .give_timebase = smp_generic_give_timebase,
> .take_timebase = smp_generic_take_timebase,
> @@ -277,8 +338,7 @@ static void mpc85xx_smp_machine_kexec(struct kimage *image)
> }
> #endif /* CONFIG_KEXEC */
>
> -static void __init
> -smp_85xx_setup_cpu(int cpu_nr)
> +static void __cpuinit smp_85xx_setup_cpu(int cpu_nr)
> {
> if (smp_85xx_ops.probe == smp_mpic_probe)
> mpic_setup_this_cpu();
> @@ -329,6 +389,9 @@ void __init mpc85xx_smp_init(void)
> }
> smp_85xx_ops.give_timebase = mpc85xx_give_timebase;
> smp_85xx_ops.take_timebase = mpc85xx_take_timebase;
> +#ifdef CONFIG_HOTPLUG_CPU
> + ppc_md.cpu_die = smp_85xx_mach_cpu_die;
> +#endif
> }
>
> smp_ops = &smp_85xx_ops;
> --
> 1.6.4.1
>
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