Re: [PATCH v2,4/5] PowerPC/mpc85xx: Add hotplug support on E5500 and E500MC cores

2015-08-27 Thread Chenhui Zhao 



On Thu, Aug 27, 2015 at 4:55 AM, Scott Wood  
wrote:

On Wed, Aug 26, 2015 at 08:09:47PM +0800, Chenhui Zhao wrote:

 +int check_cpu_dead(unsigned int cpu)
 +{
 +  return per_cpu(cpu_state, cpu) == CPU_DEAD;
 +}


I'm not sure this needs to be a function versus open-coded, but if 
you do
want to make it a function, make it more obvious from the caller side 
by

changing it to:

bool is_cpu_dead(unsigned int cpu);

Otherwise if I see "if (check_cpu_dead(cpu))" I don't know if the
if-block is executed if the CPU is dead or if it isn't.


OK.




 diff --git a/arch/powerpc/platforms/85xx/smp.h 
b/arch/powerpc/platforms/85xx/smp.h

 index 0b20ae3..8ee19a3 100644
 --- a/arch/powerpc/platforms/85xx/smp.h
 +++ b/arch/powerpc/platforms/85xx/smp.h
 @@ -6,6 +6,7 @@
  #ifdef CONFIG_SMP
  void __init mpc85xx_smp_init(void);
  int __init mpc85xx_setup_pmc(void);
 +int __init fsl_rcpm_init(void);
  #else


Why wasn't this added in the patch that added fsl_rcpm_init()?

-Scott


Will move it to there.

Thanks,
-Chenhui

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH v2,4/5] PowerPC/mpc85xx: Add hotplug support on E5500 and E500MC cores

2015-08-27 Thread Chenhui Zhao 



On Thu, Aug 27, 2015 at 4:55 AM, Scott Wood scottw...@freescale.com 
wrote:

On Wed, Aug 26, 2015 at 08:09:47PM +0800, Chenhui Zhao wrote:

 +int check_cpu_dead(unsigned int cpu)
 +{
 +  return per_cpu(cpu_state, cpu) == CPU_DEAD;
 +}


I'm not sure this needs to be a function versus open-coded, but if 
you do
want to make it a function, make it more obvious from the caller side 
by

changing it to:

bool is_cpu_dead(unsigned int cpu);

Otherwise if I see if (check_cpu_dead(cpu)) I don't know if the
if-block is executed if the CPU is dead or if it isn't.


OK.




 diff --git a/arch/powerpc/platforms/85xx/smp.h 
b/arch/powerpc/platforms/85xx/smp.h

 index 0b20ae3..8ee19a3 100644
 --- a/arch/powerpc/platforms/85xx/smp.h
 +++ b/arch/powerpc/platforms/85xx/smp.h
 @@ -6,6 +6,7 @@
  #ifdef CONFIG_SMP
  void __init mpc85xx_smp_init(void);
  int __init mpc85xx_setup_pmc(void);
 +int __init fsl_rcpm_init(void);
  #else


Why wasn't this added in the patch that added fsl_rcpm_init()?

-Scott


Will move it to there.

Thanks,
-Chenhui

--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Re: [PATCH v2,4/5] PowerPC/mpc85xx: Add hotplug support on E5500 and E500MC cores

2015-08-26 Thread Scott Wood 
On Wed, Aug 26, 2015 at 08:09:47PM +0800, Chenhui Zhao wrote:
> +int check_cpu_dead(unsigned int cpu)
> +{
> + return per_cpu(cpu_state, cpu) == CPU_DEAD;
> +}

I'm not sure this needs to be a function versus open-coded, but if you do
want to make it a function, make it more obvious from the caller side by
changing it to:

bool is_cpu_dead(unsigned int cpu);

Otherwise if I see "if (check_cpu_dead(cpu))" I don't know if the
if-block is executed if the CPU is dead or if it isn't.

> diff --git a/arch/powerpc/platforms/85xx/smp.h 
> b/arch/powerpc/platforms/85xx/smp.h
> index 0b20ae3..8ee19a3 100644
> --- a/arch/powerpc/platforms/85xx/smp.h
> +++ b/arch/powerpc/platforms/85xx/smp.h
> @@ -6,6 +6,7 @@
>  #ifdef CONFIG_SMP
>  void __init mpc85xx_smp_init(void);
>  int __init mpc85xx_setup_pmc(void);
> +int __init fsl_rcpm_init(void);
>  #else

Why wasn't this added in the patch that added fsl_rcpm_init()?

-Scott
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[PATCH v2,4/5] PowerPC/mpc85xx: Add hotplug support on E5500 and E500MC cores

2015-08-26 Thread Chenhui Zhao 
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 
Signed-off-by: Tang Yuantian 
---
major changes for v2:
* factor out smp_85xx_start_cpu()
* move fsl_rcpm_init() into mpc85xx_smp_init() due to the init sequence
* add hard_irq_disable() after local_irq_save(). for platforms that
  implement lazy enabling/disabling of interrupts, call hard_irq_disable()
  to ensure interrupts are disabled physically.

 arch/powerpc/Kconfig  |   2 +-
 arch/powerpc/include/asm/smp.h|   3 +
 arch/powerpc/kernel/smp.c |   7 +-
 arch/powerpc/platforms/85xx/smp.c | 193 ++
 arch/powerpc/platforms/85xx/smp.h |   1 +
 5 files changed, 122 insertions(+), 84 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..4ff5b71 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -67,6 +67,9 @@ 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 check_cpu_dead(unsigned int cpu);
+#else
+#define generic_set_cpu_up(i)  do { } while (0)
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ec9ec20..95111f2 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -427,7 +427,7 @@ void generic_cpu_die(unsigned int cpu)
 
for (i = 0; i < 100; i++) {
smp_rmb();
-   if (per_cpu(cpu_state, cpu) == CPU_DEAD)
+   if (check_cpu_dead(cpu))
return;
msleep(100);
}
@@ -454,6 +454,11 @@ int generic_check_cpu_restart(unsigned int cpu)
return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 }
 
+int check_cpu_dead(unsigned int cpu)
+{
+   return per_cpu(cpu_state, cpu) == CPU_DEAD;
+}
+
 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 f9552b8..73eb994 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -10,6 +10,8 @@
  * option) any later version.
  */
 
+#define pr_fmt(fmt) "smp: %s: " fmt, __func__
+
 #include 
 #include 
 #include 
@@ -52,6 +54,7 @@ static void mpc85xx_give_timebase(void)
unsigned long flags;
 
local_irq_save(flags);
+   hard_irq_disable();
 
while (!tb_req)
barrier();
@@ -100,6 +103,7 @@ static void mpc85xx_take_timebase(void)
unsigned long flags;
 
local_irq_save(flags);
+   hard_irq_disable();
 
tb_req = 1;
while (!tb_valid)
@@ -135,8 +139,31 @@ static void smp_85xx_mach_cpu_die(void)
while (1)
;
 }
+
+static void qoriq_cpu_kill(unsigned int cpu)
+{
+   int i;
+
+   for (i = 0; i < 500; i++) {
+   if (check_cpu_dead(cpu)) {
+#ifdef CONFIG_PPC64
+   paca[cpu].cpu_start = 0;
+#endif
+   return;
+   }
+   msleep(20);
+   }
+   pr_err("CPU%d didn't die...\n", cpu);
+}
 #endif
 
+/*
+ * To keep it compatible with old boot program which uses
+ * cache-inhibit spin table, we need to flush the cache
+ * before accessing spin table to invalidate any staled data.
+ * We also need to flush the cache after writing to spin
+ * table to push data out.
+ */
 static inline void flush_spin_table(void *spin_table)
 {
flush_dcache_range((ulong)spin_table,
@@ -168,51 +195,20 @@ static void wake_hw_thread(void *info)
 }
 #endif
 
-static int smp_85xx_kick_cpu(int nr)
+static int smp_85xx_start_cpu(int cpu)
 {
-   unsigned long flags;
-   const u64 *cpu_rel_addr;
-   __iomem struct epapr_spin_table *spin_table;
+   int ret = 0;
struct device_node *np;
-   int hw_cpu = get_hard_smp_processor_id(nr);
+   const u64 *cpu_rel_addr;
+   unsigned long flags;
int ioremappable;
-   int ret = 0;
-
-   WARN_ON(nr < 0 || nr >= NR_CPUS);
-   WARN_ON(hw_cpu < 0 || hw_cpu >= NR_CPUS);
-
-   pr_debug("smp_85xx_kick_cpu: kick CPU #%d\n", nr);
-
-#ifdef CONFIG_PPC64
-   /* Threads don't use the spin table */
-   if (cpu_thread_in_core(nr) != 0) {
-

Re: [PATCH v2,4/5] PowerPC/mpc85xx: Add hotplug support on E5500 and E500MC cores

2015-08-26 Thread Scott Wood 
On Wed, Aug 26, 2015 at 08:09:47PM +0800, Chenhui Zhao wrote:
 +int check_cpu_dead(unsigned int cpu)
 +{
 + return per_cpu(cpu_state, cpu) == CPU_DEAD;
 +}

I'm not sure this needs to be a function versus open-coded, but if you do
want to make it a function, make it more obvious from the caller side by
changing it to:

bool is_cpu_dead(unsigned int cpu);

Otherwise if I see if (check_cpu_dead(cpu)) I don't know if the
if-block is executed if the CPU is dead or if it isn't.

 diff --git a/arch/powerpc/platforms/85xx/smp.h 
 b/arch/powerpc/platforms/85xx/smp.h
 index 0b20ae3..8ee19a3 100644
 --- a/arch/powerpc/platforms/85xx/smp.h
 +++ b/arch/powerpc/platforms/85xx/smp.h
 @@ -6,6 +6,7 @@
  #ifdef CONFIG_SMP
  void __init mpc85xx_smp_init(void);
  int __init mpc85xx_setup_pmc(void);
 +int __init fsl_rcpm_init(void);
  #else

Why wasn't this added in the patch that added fsl_rcpm_init()?

-Scott
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[PATCH v2,4/5] PowerPC/mpc85xx: Add hotplug support on E5500 and E500MC cores

2015-08-26 Thread Chenhui Zhao 
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
---
major changes for v2:
* factor out smp_85xx_start_cpu()
* move fsl_rcpm_init() into mpc85xx_smp_init() due to the init sequence
* add hard_irq_disable() after local_irq_save(). for platforms that
  implement lazy enabling/disabling of interrupts, call hard_irq_disable()
  to ensure interrupts are disabled physically.

 arch/powerpc/Kconfig  |   2 +-
 arch/powerpc/include/asm/smp.h|   3 +
 arch/powerpc/kernel/smp.c |   7 +-
 arch/powerpc/platforms/85xx/smp.c | 193 ++
 arch/powerpc/platforms/85xx/smp.h |   1 +
 5 files changed, 122 insertions(+), 84 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..4ff5b71 100644
--- a/arch/powerpc/include/asm/smp.h
+++ b/arch/powerpc/include/asm/smp.h
@@ -67,6 +67,9 @@ 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 check_cpu_dead(unsigned int cpu);
+#else
+#define generic_set_cpu_up(i)  do { } while (0)
 #endif
 
 #ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ec9ec20..95111f2 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -427,7 +427,7 @@ void generic_cpu_die(unsigned int cpu)
 
for (i = 0; i  100; i++) {
smp_rmb();
-   if (per_cpu(cpu_state, cpu) == CPU_DEAD)
+   if (check_cpu_dead(cpu))
return;
msleep(100);
}
@@ -454,6 +454,11 @@ int generic_check_cpu_restart(unsigned int cpu)
return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 }
 
+int check_cpu_dead(unsigned int cpu)
+{
+   return per_cpu(cpu_state, cpu) == CPU_DEAD;
+}
+
 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 f9552b8..73eb994 100644
--- a/arch/powerpc/platforms/85xx/smp.c
+++ b/arch/powerpc/platforms/85xx/smp.c
@@ -10,6 +10,8 @@
  * option) any later version.
  */
 
+#define pr_fmt(fmt) smp: %s:  fmt, __func__
+
 #include linux/stddef.h
 #include linux/kernel.h
 #include linux/init.h
@@ -52,6 +54,7 @@ static void mpc85xx_give_timebase(void)
unsigned long flags;
 
local_irq_save(flags);
+   hard_irq_disable();
 
while (!tb_req)
barrier();
@@ -100,6 +103,7 @@ static void mpc85xx_take_timebase(void)
unsigned long flags;
 
local_irq_save(flags);
+   hard_irq_disable();
 
tb_req = 1;
while (!tb_valid)
@@ -135,8 +139,31 @@ static void smp_85xx_mach_cpu_die(void)
while (1)
;
 }
+
+static void qoriq_cpu_kill(unsigned int cpu)
+{
+   int i;
+
+   for (i = 0; i  500; i++) {
+   if (check_cpu_dead(cpu)) {
+#ifdef CONFIG_PPC64
+   paca[cpu].cpu_start = 0;
+#endif
+   return;
+   }
+   msleep(20);
+   }
+   pr_err(CPU%d didn't die...\n, cpu);
+}
 #endif
 
+/*
+ * To keep it compatible with old boot program which uses
+ * cache-inhibit spin table, we need to flush the cache
+ * before accessing spin table to invalidate any staled data.
+ * We also need to flush the cache after writing to spin
+ * table to push data out.
+ */
 static inline void flush_spin_table(void *spin_table)
 {
flush_dcache_range((ulong)spin_table,
@@ -168,51 +195,20 @@ static void wake_hw_thread(void *info)
 }
 #endif
 
-static int smp_85xx_kick_cpu(int nr)
+static int smp_85xx_start_cpu(int cpu)
 {
-   unsigned long flags;
-   const u64 *cpu_rel_addr;
-   __iomem struct epapr_spin_table *spin_table;
+   int ret = 0;
struct device_node *np;
-   int hw_cpu = get_hard_smp_processor_id(nr);
+   const u64 *cpu_rel_addr;
+   unsigned long flags;
int ioremappable;
-   int ret = 0;
-
-   WARN_ON(nr  0 || nr = NR_CPUS);
-   WARN_ON(hw_cpu  0 || hw_cpu = NR_CPUS);
-
-   pr_debug(smp_85xx_kick_cpu: kick CPU #%d\n, nr);
-
-#ifdef CONFIG_PPC64
-   /* Threads don't