[PATCH v4 1/4] powerpc/85xx: add HOTPLUG_CPU support
From: Zhao Chenhui
Date: Fri Mar 16 2012 - 05:20:24 EST
From: Li Yang <leoli@xxxxxxxxxxxxx>
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().
Signed-off-by: Li Yang <leoli@xxxxxxxxxxxxx>
Signed-off-by: Jin Qing <b24347@xxxxxxxxxxxxx>
Signed-off-by: Zhao Chenhui <chenhui.zhao@xxxxxxxxxxxxx>
---
Changes for v4:
* used spin_event_timeout()
* fixed build problem with corenet32_smp_defconfig
* code cleanup
arch/powerpc/Kconfig | 6 +-
arch/powerpc/include/asm/cacheflush.h | 6 ++
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 | 146 ++++++++++++++++++++++++---------
6 files changed, 157 insertions(+), 41 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4eecaaa..3d4c497 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -219,7 +219,8 @@ 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
@@ -330,7 +331,8 @@ 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)
---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..57b5dd7 100644
--- a/arch/powerpc/include/asm/cacheflush.h
+++ b/arch/powerpc/include/asm/cacheflush.h
@@ -30,6 +30,12 @@ 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)
+#ifdef CONFIG_FSL_BOOKE
+extern void flush_disable_L1(void);
+#else
+#define flush_disable_L1() do { } while (0)
+#endif
+
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 adba970..7517863 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
@@ -191,6 +192,7 @@ 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 28e6259..e654f97 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -1004,6 +1004,34 @@ _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 46695fe..cc18a70 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 ff42490..f24b2b4 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -2,7 +2,7 @@
* Author: Andy Fleming <afleming@xxxxxxxxxxxxx>
* Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
*
- * 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>
@@ -29,28 +30,59 @@
#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))
-
-static int __init
-smp_85xx_kick_cpu(int nr)
+struct epapr_spin_table {
+ u32 addr_h;
+ u32 addr_l;
+ u32 r3_h;
+ u32 r3_l;
+ u32 reserved;
+ u32 pir;
+};
+
+static void __cpuinit smp_85xx_setup_cpu(int cpu_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;
+ mb();
+ isync();
+ 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);
@@ -75,50 +107,83 @@ 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 upon it 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_KEXEC
+#ifdef CONFIG_HOTPLUG_CPU
+ .cpu_disable = generic_cpu_disable,
+ .cpu_die = generic_cpu_die,
+#endif
.give_timebase = smp_generic_give_timebase,
.take_timebase = smp_generic_take_timebase,
-#endif
};
#ifdef CONFIG_KEXEC
@@ -218,8 +283,7 @@ 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();
@@ -249,6 +313,10 @@ void __init mpc85xx_smp_init(void)
smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
}
+#ifdef CONFIG_HOTPLUG_CPU
+ ppc_md.cpu_die = smp_85xx_mach_cpu_die;
+#endif
+
smp_ops = &smp_85xx_ops;
#ifdef CONFIG_KEXEC
--
1.6.4.1
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