parisc: ensure broadcast tlb purge runs single threaded
The TLB flushing functions on hppa, which causes PxTLB broadcasts on the system
bus, needs to be protected by irq-safe spinlocks to avoid irq handlers to deadlock
the kernel. The deadlocks only happened during I/O intensive loads and triggered
pretty seldom, which is why this bug went so long unnoticed.
Signed-off-by: Helge Deller <deller@gmx.de>
[edited to use spin_lock_irqsave on UP as well since we'd been locking there
all this time anyway, --kyle]
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
diff --git a/arch/parisc/include/asm/tlbflush.h b/arch/parisc/include/asm/tlbflush.h
index 1f6fd4f..8f1a810 100644
--- a/arch/parisc/include/asm/tlbflush.h
+++ b/arch/parisc/include/asm/tlbflush.h
@@ -12,14 +12,12 @@
* N class systems, only one PxTLB inter processor broadcast can be
* active at any one time on the Merced bus. This tlb purge
* synchronisation is fairly lightweight and harmless so we activate
- * it on all SMP systems not just the N class. We also need to have
- * preemption disabled on uniprocessor machines, and spin_lock does that
- * nicely.
+ * it on all systems not just the N class.
*/
extern spinlock_t pa_tlb_lock;
-#define purge_tlb_start(x) spin_lock(&pa_tlb_lock)
-#define purge_tlb_end(x) spin_unlock(&pa_tlb_lock)
+#define purge_tlb_start(flags) spin_lock_irqsave(&pa_tlb_lock, flags)
+#define purge_tlb_end(flags) spin_unlock_irqrestore(&pa_tlb_lock, flags)
extern void flush_tlb_all(void);
extern void flush_tlb_all_local(void *);
@@ -63,14 +61,16 @@
static inline void flush_tlb_page(struct vm_area_struct *vma,
unsigned long addr)
{
+ unsigned long flags;
+
/* For one page, it's not worth testing the split_tlb variable */
mb();
mtsp(vma->vm_mm->context,1);
- purge_tlb_start();
+ purge_tlb_start(flags);
pdtlb(addr);
pitlb(addr);
- purge_tlb_end();
+ purge_tlb_end(flags);
}
void __flush_tlb_range(unsigned long sid,