parisc: fix irq stack on UP and SMP

The logic to detect if the irq stack was already in use with
raw_spin_trylock() is wrong, because it will generate a "trylock failure
on UP" error message with CONFIG_SMP=n and CONFIG_DEBUG_SPINLOCK=y.

arch_spin_trylock() can't be used either since in the CONFIG_SMP=n case
no atomic protection is given and we are reentrant here. A mutex didn't
worked either and brings more overhead by turning off interrupts.

So, let's use the fastest path for parisc which is the ldcw instruction.

Counting how often the irq stack was used is pretty useless, so just
drop this piece of code.

Signed-off-by: Helge Deller <deller@gmx.de>

1 files changed, 0 insertions, 5 deletions

diff --git a/arch/parisc/include/asm/hardirq.h b/arch/parisc/include/asm/hardirq.h
index 4c6dd8da1e5d..241c34518465 100644
--- a/arch/parisc/include/asm/hardirq.h
+++ b/arch/parisc/include/asm/hardirq.h
@@ -17,13 +17,8 @@
 
 typedef struct {
         unsigned int __softirq_pending;
-#ifdef CONFIG_DEBUG_STACKOVERFLOW
         unsigned int kernel_stack_usage;
-#ifdef CONFIG_IRQSTACKS
         unsigned int irq_stack_usage;
-        unsigned int irq_stack_counter;
-#endif
-#endif
 #ifdef CONFIG_SMP
         unsigned int irq_resched_count;
         unsigned int irq_call_count;