[MIPS] SMTC: Make ack_bad_irq() safe with no IM backstop.

Issue reported and original patch by Kevin Kissel, cleaner (imho)
implementation by me.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

4 files changed, 8 insertions, 22 deletions

diff --git a/arch/mips/kernel/i8259.c b/arch/mips/kernel/i8259.c
index b6c30800c66..3a2d255361b 100644
--- a/arch/mips/kernel/i8259.c
+++ b/arch/mips/kernel/i8259.c
@@ -177,10 +177,7 @@ handle_real_irq:
                 outb(cached_master_mask, PIC_MASTER_IMR);
                 outb(0x60+irq,PIC_MASTER_CMD);  /* 'Specific EOI to master */
         }
-#ifdef CONFIG_MIPS_MT_SMTC
-        if (irq_hwmask[irq] & ST0_IM)
-                set_c0_status(irq_hwmask[irq] & ST0_IM);
-#endif /* CONFIG_MIPS_MT_SMTC */
+        smtc_im_ack_irq(irq);
         spin_unlock_irqrestore(&i8259A_lock, flags);
         return;
 
diff --git a/arch/mips/kernel/irq-msc01.c b/arch/mips/kernel/irq-msc01.c
index 410868b5ea5..1ecdd50bfc6 100644
--- a/arch/mips/kernel/irq-msc01.c
+++ b/arch/mips/kernel/irq-msc01.c
@@ -52,11 +52,8 @@ static void level_mask_and_ack_msc_irq(unsigned int irq)
         mask_msc_irq(irq);
         if (!cpu_has_veic)
                 MSCIC_WRITE(MSC01_IC_EOI, 0);
-#ifdef CONFIG_MIPS_MT_SMTC
         /* This actually needs to be a call into platform code */
-        if (irq_hwmask[irq] & ST0_IM)
-                set_c0_status(irq_hwmask[irq] & ST0_IM);
-#endif /* CONFIG_MIPS_MT_SMTC */
+        smtc_im_ack_irq(irq);
 }
 
 /*
@@ -73,10 +70,7 @@ static void edge_mask_and_ack_msc_irq(unsigned int irq)
                 MSCIC_WRITE(MSC01_IC_SUP+irq*8, r | ~MSC01_IC_SUP_EDGE_BIT);
                 MSCIC_WRITE(MSC01_IC_SUP+irq*8, r);
         }
-#ifdef CONFIG_MIPS_MT_SMTC
-        if (irq_hwmask[irq] & ST0_IM)
-                set_c0_status(irq_hwmask[irq] & ST0_IM);
-#endif /* CONFIG_MIPS_MT_SMTC */
+        smtc_im_ack_irq(irq);
 }
 
 /*
diff --git a/arch/mips/kernel/irq.c b/arch/mips/kernel/irq.c
index aeded6c17de..a990aad2f04 100644
--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c
@@ -74,20 +74,12 @@ EXPORT_SYMBOL_GPL(free_irqno);
  */
 void ack_bad_irq(unsigned int irq)
 {
+        smtc_im_ack_irq(irq);
         printk("unexpected IRQ # %d\n", irq);
 }
 
 atomic_t irq_err_count;
 
-#ifdef CONFIG_MIPS_MT_SMTC
-/*
- * SMTC Kernel needs to manipulate low-level CPU interrupt mask
- * in do_IRQ. These are passed in setup_irq_smtc() and stored
- * in this table.
- */
-unsigned long irq_hwmask[NR_IRQS];
-#endif /* CONFIG_MIPS_MT_SMTC */
-
 /*
  * Generic, controller-independent functions:
  */
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c
index 43826c16101..f09404377ef 100644
--- a/arch/mips/kernel/smtc.c
+++ b/arch/mips/kernel/smtc.c
@@ -25,8 +25,11 @@
 #include <asm/smtc_proc.h>
 
 /*
- * This file should be built into the kernel only if CONFIG_MIPS_MT_SMTC is set.
+ * SMTC Kernel needs to manipulate low-level CPU interrupt mask
+ * in do_IRQ. These are passed in setup_irq_smtc() and stored
+ * in this table.
  */
+unsigned long irq_hwmask[NR_IRQS];
 
 #define LOCK_MT_PRA() \
         local_irq_save(flags); \