[PATCH -rt] powerpc update

From: Daniel Walker
Date: Tue Oct 03 2006 - 11:57:09 EST


This updates arch/powerpc/ so that it boots PREEMPT_RT on a Apple
G4 PowerBook. It should also get other powerpc boards functional to
some extent.

Pay close attention to the fasteoi interrupt threading. I added usage
of mask/unmask instead of using level handling, which worked well on PPC.

There is still a todo to update highmems kmap_atomic() for realtime.
So don't turn on highmem.

Signed-Off-By: Daniel Walker <dwalker@xxxxxxxxxx>

---
arch/powerpc/Kconfig.debug | 4 ++++
arch/powerpc/kernel/idle.c | 2 +-
drivers/macintosh/adb.c | 13 +++++++------
drivers/net/sungem.c | 4 +---
include/asm-powerpc/hw_irq.h | 2 +-
include/asm-powerpc/pmac_feature.h | 2 +-
kernel/irq/chip.c | 17 +++++++++++------
7 files changed, 26 insertions(+), 18 deletions(-)

Index: linux-2.6.18/arch/powerpc/Kconfig.debug
===================================================================
--- linux-2.6.18.orig/arch/powerpc/Kconfig.debug
+++ linux-2.6.18/arch/powerpc/Kconfig.debug
@@ -2,6 +2,10 @@ menu "Kernel hacking"

source "lib/Kconfig.debug"

+config TRACE_IRQFLAGS_SUPPORT
+ bool
+ default y
+
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL && PPC64
Index: linux-2.6.18/arch/powerpc/kernel/idle.c
===================================================================
--- linux-2.6.18.orig/arch/powerpc/kernel/idle.c
+++ linux-2.6.18/arch/powerpc/kernel/idle.c
@@ -82,7 +82,7 @@ void cpu_idle(void)
ppc64_runlatch_on();
if (cpu_should_die())
cpu_die();
- preempt_enable_no_resched();
+ __preempt_enable_no_resched();
schedule();
preempt_disable();
}
Index: linux-2.6.18/drivers/macintosh/adb.c
===================================================================
--- linux-2.6.18.orig/drivers/macintosh/adb.c
+++ linux-2.6.18/drivers/macintosh/adb.c
@@ -256,6 +256,8 @@ adb_probe_task(void *x)
sigprocmask(SIG_BLOCK, &blocked, NULL);
flush_signals(current);

+ down(&adb_probe_mutex);
+
printk(KERN_INFO "adb: starting probe task...\n");
do_adb_reset_bus();
printk(KERN_INFO "adb: finished probe task...\n");
@@ -282,7 +284,9 @@ adb_reset_bus(void)
return 0;
}

- down(&adb_probe_mutex);
+ if (adb_got_sleep)
+ return 0;
+
schedule_work(&adb_reset_work);
return 0;
}
@@ -347,23 +351,21 @@ adb_notify_sleep(struct pmu_sleep_notifi

switch (when) {
case PBOOK_SLEEP_REQUEST:
+ /* Signal to discontiue probing */
adb_got_sleep = 1;
- /* We need to get a lock on the probe thread */
- down(&adb_probe_mutex);
/* Stop autopoll */
if (adb_controller->autopoll)
adb_controller->autopoll(0);
ret = blocking_notifier_call_chain(&adb_client_list,
ADB_MSG_POWERDOWN, NULL);
if (ret & NOTIFY_STOP_MASK) {
- up(&adb_probe_mutex);
+ adb_got_sleep = 0;
return PBOOK_SLEEP_REFUSE;
}
break;
case PBOOK_SLEEP_REJECT:
if (adb_got_sleep) {
adb_got_sleep = 0;
- up(&adb_probe_mutex);
adb_reset_bus();
}
break;
@@ -372,7 +374,6 @@ adb_notify_sleep(struct pmu_sleep_notifi
break;
case PBOOK_WAKE:
adb_got_sleep = 0;
- up(&adb_probe_mutex);
adb_reset_bus();
break;
}
Index: linux-2.6.18/drivers/net/sungem.c
===================================================================
--- linux-2.6.18.orig/drivers/net/sungem.c
+++ linux-2.6.18/drivers/net/sungem.c
@@ -1037,10 +1037,8 @@ static int gem_start_xmit(struct sk_buff
(csum_stuff_off << 21));
}

- local_irq_save(flags);
- if (!spin_trylock(&gp->tx_lock)) {
+ if (!spin_trylock_irqsave(&gp->tx_lock, flags)) {
/* Tell upper layer to requeue */
- local_irq_restore(flags);
return NETDEV_TX_LOCKED;
}
/* We raced with gem_do_stop() */
Index: linux-2.6.18/include/asm-powerpc/hw_irq.h
===================================================================
--- linux-2.6.18.orig/include/asm-powerpc/hw_irq.h
+++ linux-2.6.18/include/asm-powerpc/hw_irq.h
@@ -85,7 +85,7 @@ static inline void raw_local_irq_save_pt

#endif /* CONFIG_PPC_ISERIES */

-#include <linux/trace_irqflags.h>
+#include <linux/irqflags.h>

#define mask_irq(irq) \
({ \
Index: linux-2.6.18/include/asm-powerpc/pmac_feature.h
===================================================================
--- linux-2.6.18.orig/include/asm-powerpc/pmac_feature.h
+++ linux-2.6.18/include/asm-powerpc/pmac_feature.h
@@ -378,7 +378,7 @@ extern struct macio_chip* macio_find(str
* Those are exported by pmac feature for internal use by arch code
* only like the platform function callbacks, do not use directly in drivers
*/
-extern spinlock_t feature_lock;
+extern raw_spinlock_t feature_lock;
extern struct device_node *uninorth_node;
extern u32 __iomem *uninorth_base;

Index: linux-2.6.18/kernel/irq/chip.c
===================================================================
--- linux-2.6.18.orig/kernel/irq/chip.c
+++ linux-2.6.18/kernel/irq/chip.c
@@ -386,13 +386,19 @@ handle_fasteoi_irq(unsigned int irq, str
}

desc->status |= IRQ_INPROGRESS;
- /*
- * fasteoi should not be used for threaded IRQ handlers!
- */
+
if (redirect_hardirq(desc)) {
- WARN_ON_ONCE(1);
- goto out_unlock;
+ if (desc->chip->mask)
+ desc->chip->mask(irq);
+ else
+ /*
+ * Threading on eoi chips w/o a mask/unmask is not
+ * likely to work well.
+ */
+ WARN_ON_ONCE(1);
+ goto out;
}
+
desc->status &= ~IRQ_PENDING;
spin_unlock(&desc->lock);

@@ -404,7 +410,6 @@ handle_fasteoi_irq(unsigned int irq, str
desc->status &= ~IRQ_INPROGRESS;
out:
desc->chip->eoi(irq);
-out_unlock:
spin_unlock(&desc->lock);
}

--
-
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