powerpc: Use one common impl. of RTAS timebase sync and use raw spinlock
Several platforms use their own copy of what is essentially the same code,
using RTAS to synchronize the timebases when bringing up new CPUs. This
moves it all into a single common implementation and additionally
turns the spinlock into a raw spinlock since the former can rely on
the timebase not being frozen when spinlock debugging is enabled, and finally
masks interrupts while the timebase is disabled.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index 0af42d2..168fce7 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -245,5 +245,8 @@
(devfn << 8) | (reg & 0xff);
}
+extern void __cpuinit rtas_give_timebase(void);
+extern void __cpuinit rtas_take_timebase(void);
+
#endif /* __KERNEL__ */
#endif /* _POWERPC_RTAS_H */
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index d9a9974..c434823 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -38,6 +38,7 @@
#include <asm/syscalls.h>
#include <asm/smp.h>
#include <asm/atomic.h>
+#include <asm/time.h>
struct rtas_t rtas = {
.lock = __RAW_SPIN_LOCK_UNLOCKED
@@ -971,3 +972,33 @@
/* break now */
return 1;
}
+
+static raw_spinlock_t timebase_lock;
+static u64 timebase = 0;
+
+void __cpuinit rtas_give_timebase(void)
+{
+ unsigned long flags;
+
+ local_irq_save(flags);
+ hard_irq_disable();
+ __raw_spin_lock(&timebase_lock);
+ rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
+ timebase = get_tb();
+ __raw_spin_unlock(&timebase_lock);
+
+ while (timebase)
+ barrier();
+ rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
+ local_irq_restore(flags);
+}
+
+void __cpuinit rtas_take_timebase(void)
+{
+ while (!timebase)
+ barrier();
+ __raw_spin_lock(&timebase_lock);
+ set_tb(timebase >> 32, timebase & 0xffffffff);
+ timebase = 0;
+ __raw_spin_unlock(&timebase_lock);
+}
diff --git a/arch/powerpc/platforms/cell/smp.c b/arch/powerpc/platforms/cell/smp.c
index 9046803..bc97fada 100644
--- a/arch/powerpc/platforms/cell/smp.c
+++ b/arch/powerpc/platforms/cell/smp.c
@@ -36,7 +36,6 @@
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/paca.h>
-#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
@@ -140,31 +139,6 @@
mtspr(SPRN_DABRX, DABRX_KERNEL | DABRX_USER);
}
-static DEFINE_SPINLOCK(timebase_lock);
-static unsigned long timebase = 0;
-
-static void __devinit cell_give_timebase(void)
-{
- spin_lock(&timebase_lock);
- rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
- timebase = get_tb();
- spin_unlock(&timebase_lock);
-
- while (timebase)
- barrier();
- rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
-}
-
-static void __devinit cell_take_timebase(void)
-{
- while (!timebase)
- barrier();
- spin_lock(&timebase_lock);
- set_tb(timebase >> 32, timebase & 0xffffffff);
- timebase = 0;
- spin_unlock(&timebase_lock);
-}
-
static void __devinit smp_cell_kick_cpu(int nr)
{
BUG_ON(nr < 0 || nr >= NR_CPUS);
@@ -224,8 +198,8 @@
/* Non-lpar has additional take/give timebase */
if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
- smp_ops->give_timebase = cell_give_timebase;
- smp_ops->take_timebase = cell_take_timebase;
+ smp_ops->give_timebase = rtas_give_timebase;
+ smp_ops->take_timebase = rtas_take_timebase;
}
DBG(" <- smp_init_cell()\n");
diff --git a/arch/powerpc/platforms/chrp/smp.c b/arch/powerpc/platforms/chrp/smp.c
index 10a4a4d..02cafec 100644
--- a/arch/powerpc/platforms/chrp/smp.c
+++ b/arch/powerpc/platforms/chrp/smp.c
@@ -26,7 +26,6 @@
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/smp.h>
-#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/mpic.h>
#include <asm/rtas.h>
@@ -42,40 +41,12 @@
mpic_setup_this_cpu();
}
-static DEFINE_SPINLOCK(timebase_lock);
-static unsigned int timebase_upper = 0, timebase_lower = 0;
-
-void __devinit smp_chrp_give_timebase(void)
-{
- spin_lock(&timebase_lock);
- rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
- timebase_upper = get_tbu();
- timebase_lower = get_tbl();
- spin_unlock(&timebase_lock);
-
- while (timebase_upper || timebase_lower)
- barrier();
- rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
-}
-
-void __devinit smp_chrp_take_timebase(void)
-{
- while (!(timebase_upper || timebase_lower))
- barrier();
- spin_lock(&timebase_lock);
- set_tb(timebase_upper, timebase_lower);
- timebase_upper = 0;
- timebase_lower = 0;
- spin_unlock(&timebase_lock);
- printk("CPU %i taken timebase\n", smp_processor_id());
-}
-
/* CHRP with openpic */
struct smp_ops_t chrp_smp_ops = {
.message_pass = smp_mpic_message_pass,
.probe = smp_mpic_probe,
.kick_cpu = smp_chrp_kick_cpu,
.setup_cpu = smp_chrp_setup_cpu,
- .give_timebase = smp_chrp_give_timebase,
- .take_timebase = smp_chrp_take_timebase,
+ .give_timebase = rtas_give_timebase,
+ .take_timebase = rtas_take_timebase,
};
diff --git a/arch/powerpc/platforms/pseries/smp.c b/arch/powerpc/platforms/pseries/smp.c
index 1a231c3..1f8f6cf 100644
--- a/arch/powerpc/platforms/pseries/smp.c
+++ b/arch/powerpc/platforms/pseries/smp.c
@@ -35,7 +35,6 @@
#include <asm/prom.h>
#include <asm/smp.h>
#include <asm/paca.h>
-#include <asm/time.h>
#include <asm/machdep.h>
#include <asm/cputable.h>
#include <asm/firmware.h>
@@ -118,31 +117,6 @@
}
#endif /* CONFIG_XICS */
-static DEFINE_SPINLOCK(timebase_lock);
-static unsigned long timebase = 0;
-
-static void __devinit pSeries_give_timebase(void)
-{
- spin_lock(&timebase_lock);
- rtas_call(rtas_token("freeze-time-base"), 0, 1, NULL);
- timebase = get_tb();
- spin_unlock(&timebase_lock);
-
- while (timebase)
- barrier();
- rtas_call(rtas_token("thaw-time-base"), 0, 1, NULL);
-}
-
-static void __devinit pSeries_take_timebase(void)
-{
- while (!timebase)
- barrier();
- spin_lock(&timebase_lock);
- set_tb(timebase >> 32, timebase & 0xffffffff);
- timebase = 0;
- spin_unlock(&timebase_lock);
-}
-
static void __devinit smp_pSeries_kick_cpu(int nr)
{
BUG_ON(nr < 0 || nr >= NR_CPUS);
@@ -209,8 +183,8 @@
/* Non-lpar has additional take/give timebase */
if (rtas_token("freeze-time-base") != RTAS_UNKNOWN_SERVICE) {
- smp_ops->give_timebase = pSeries_give_timebase;
- smp_ops->take_timebase = pSeries_take_timebase;
+ smp_ops->give_timebase = rtas_give_timebase;
+ smp_ops->take_timebase = rtas_take_timebase;
}
pr_debug(" <- smp_init_pSeries()\n");