From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: <linuxppc-dev@ozlabs.org>
Subject: [PATCH 2/3] powerpc: Use one common impl. of RTAS timebase sync and use raw spinlock
Date: Wed, 17 Jun 2009 12:42:50 +1000 [thread overview]
Message-ID: <20090617024328.2D466DDDA0@ozlabs.org> (raw)
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>
---
arch/powerpc/include/asm/rtas.h | 3 +++
arch/powerpc/kernel/rtas.c | 31 +++++++++++++++++++++++++++++++
arch/powerpc/platforms/cell/smp.c | 30 ++----------------------------
arch/powerpc/platforms/chrp/smp.c | 30 ++----------------------------
arch/powerpc/platforms/pseries/smp.c | 30 ++----------------------------
5 files changed, 40 insertions(+), 84 deletions(-)
--- linux-work.orig/arch/powerpc/platforms/cell/smp.c 2009-06-17 11:56:31.000000000 +1000
+++ linux-work/arch/powerpc/platforms/cell/smp.c 2009-06-17 11:56:42.000000000 +1000
@@ -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 @@ static void __devinit smp_cell_setup_cpu
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 @@ void __init smp_init_cell(void)
/* 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");
Index: linux-work/arch/powerpc/platforms/chrp/smp.c
===================================================================
--- linux-work.orig/arch/powerpc/platforms/chrp/smp.c 2009-06-17 11:56:31.000000000 +1000
+++ linux-work/arch/powerpc/platforms/chrp/smp.c 2009-06-17 11:56:42.000000000 +1000
@@ -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>
@@ -45,37 +44,12 @@ static void __devinit smp_chrp_setup_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,
};
Index: linux-work/arch/powerpc/platforms/pseries/smp.c
===================================================================
--- linux-work.orig/arch/powerpc/platforms/pseries/smp.c 2009-06-17 11:56:31.000000000 +1000
+++ linux-work/arch/powerpc/platforms/pseries/smp.c 2009-06-17 11:56:42.000000000 +1000
@@ -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 @@ static void __devinit smp_xics_setup_cpu
}
#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 @@ static void __init smp_init_pseries(void
/* 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");
Index: linux-work/arch/powerpc/include/asm/rtas.h
===================================================================
--- linux-work.orig/arch/powerpc/include/asm/rtas.h 2009-06-17 11:56:31.000000000 +1000
+++ linux-work/arch/powerpc/include/asm/rtas.h 2009-06-17 11:56:42.000000000 +1000
@@ -245,5 +245,8 @@ static inline u32 rtas_config_addr(int b
(devfn << 8) | (reg & 0xff);
}
+extern void __cpuinit rtas_give_timebase(void);
+extern void __cpuinit rtas_take_timebase(void);
+
#endif /* __KERNEL__ */
#endif /* _POWERPC_RTAS_H */
Index: linux-work/arch/powerpc/kernel/rtas.c
===================================================================
--- linux-work.orig/arch/powerpc/kernel/rtas.c 2009-06-17 11:56:31.000000000 +1000
+++ linux-work/arch/powerpc/kernel/rtas.c 2009-06-17 11:59:58.000000000 +1000
@@ -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 @@ int __init early_init_dt_scan_rtas(unsig
/* 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);
+}
reply other threads:[~2009-06-17 2:43 UTC|newest]
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