On Sat, Aug 1, 2015 at 8:14 AM, Scott Wood <scottw...@freescale.com>
wrote:
On Fri, 2015-07-31 at 17:20 +0800, b29...@freescale.com wrote:
From: Tang Yuantian <yuantian.t...@freescale.com>
Freescale E500MC and E5500 core-based platforms, like P4080, T1040,
support disabling/enabling CPU dynamically.
This patch adds this feature on those platforms.
Signed-off-by: Chenhui Zhao <chenhui.z...@freescale.com>
Signed-off-by: Tang Yuantian <yuantian.t...@feescale.com>
---
arch/powerpc/Kconfig | 2 +-
arch/powerpc/include/asm/smp.h | 1 +
arch/powerpc/kernel/smp.c | 5 +++++
arch/powerpc/platforms/85xx/smp.c | 39
++++++++++++++++++++++++++++++++----
---
4 files changed, 39 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 5ef2711..dd9e252 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -386,7 +386,7 @@ config SWIOTLB
config HOTPLUG_CPU
bool "Support for enabling/disabling CPUs"
depends on SMP && (PPC_PSERIES || \
- PPC_PMAC || PPC_POWERNV || (PPC_85xx && !PPC_E500MC))
+ PPC_PMAC || PPC_POWERNV || FSL_SOC_BOOKE)
---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/smp.h
b/arch/powerpc/include/asm/smp.h
index 825663c..bf37d17 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -67,6 +67,7 @@ void generic_cpu_die(unsigned int cpu);
void generic_set_cpu_dead(unsigned int cpu);
void generic_set_cpu_up(unsigned int cpu);
int generic_check_cpu_restart(unsigned int cpu);
+int generic_check_cpu_dead(unsigned int cpu);
#endif
#ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ec9ec20..2cca27a 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -454,6 +454,11 @@ int generic_check_cpu_restart(unsigned int cpu)
return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
}
+int generic_check_cpu_dead(unsigned int cpu)
+{
+ return per_cpu(cpu_state, cpu) == CPU_DEAD;
+}
Is there a non-generic check_cpu_dead()?
NO, just follow the name "generic_check_cpu_restart()".
It gets open-coded in generic_cpu_die()... Either open-code it
elsewhere, or
call it check_cpu_dead() and use it everywhere there's a CPU_DEAD
check.
+
static bool secondaries_inhibited(void)
{
return kvm_hv_mode_active();
diff --git a/arch/powerpc/platforms/85xx/smp.c
b/arch/powerpc/platforms/85xx/smp.c
index 6811a5b..7f0dadb 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -42,6 +42,7 @@ struct epapr_spin_table {
u32 pir;
};
+#ifdef CONFIG_HOTPLUG_CPU
static u64 timebase;
static int tb_req;
static int tb_valid;
@@ -111,7 +112,7 @@ static void mpc85xx_take_timebase(void)
local_irq_restore(flags);
}
-#ifdef CONFIG_HOTPLUG_CPU
+#ifndef CONFIG_PPC_E500MC
static void e500_cpu_idle(void)
What happens if we bisect to patch 1/3 and run this on e500mc?
Please move the ifdef to that patch.
OK.
{
u32 tmp;
@@ -127,6 +128,7 @@ static void e500_cpu_idle(void)
mtmsr(tmp);
isync();
}
+#endif
static void qoriq_cpu_dying(void)
{
@@ -144,11 +146,30 @@ static void qoriq_cpu_dying(void)
generic_set_cpu_dead(cpu);
+#ifndef CONFIG_PPC_E500MC
e500_cpu_idle();
+#endif
while (1)
;
}
+
+static void qoriq_real_cpu_die(unsigned int cpu)
Real as opposed to...?
It's hard to find a good name. :)
+{
+ int i;
+
+ for (i = 0; i < 50000; i++) {
+ if (generic_check_cpu_dead(cpu)) {
+ qoriq_pm_ops->cpu_die(cpu);
+#ifdef CONFIG_PPC64
+ paca[cpu].cpu_start = 0;
+#endif
+ return;
+ }
+ udelay(10);
+ }
+ pr_err("%s: CPU%d didn't die...\n", __func__, cpu);
+}
Only 500ms timeout, versus 10sec in generic_cpu_die()?
The process is fast. Maybe 10 second is too large.
#endif
static inline void flush_spin_table(void *spin_table)
@@ -246,11 +267,7 @@ static int smp_85xx_kick_cpu(int nr)
spin_table = phys_to_virt(*cpu_rel_addr);
local_irq_save(flags);
-#ifdef CONFIG_PPC32
#ifdef CONFIG_HOTPLUG_CPU
- /* Corresponding to generic_set_cpu_dead() */
- generic_set_cpu_up(nr);
-
if (system_state == SYSTEM_RUNNING) {
/*
* To keep it compatible with old boot program which
uses
@@ -263,6 +280,7 @@ static int smp_85xx_kick_cpu(int nr)
out_be32(&spin_table->addr_l, 0);
flush_spin_table(spin_table);
+ qoriq_pm_ops->cpu_up(nr);
Again, is it possible to get here without a valid qoriq_pm_ops (i.e.
is there
anything stopping the user from trying to initiate CPU hotplug)?
-Scott
For every platform running this code, should has a valid qoriq_pm_ops.
If not valid, it's a bug.
-Chenhui
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