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) {
-
