iop3xx_cp6_disable();
 }
 
+static inline void intbase_write(u32 val)
+{
+       iop3xx_cp6_enable();
+       asm volatile("mcr p6, 0, %0, c12, c0, 0" : : "r" (val));
+       iop3xx_cp6_disable();
+}
+
+static inline void intsize_write(u32 val)
+{
+       iop3xx_cp6_enable();
+       asm volatile("mcr p6, 0, %0, c13, c0, 0" : : "r" (val));
+       iop3xx_cp6_disable();
+}
+
 static void
 iop331_irq_mask1 (unsigned int irq)
 {
        intctl_write1(0);
        intstr_write0(0);               // treat all as IRQ
        intstr_write1(0);
+       intbase_write(0);
+       intsize_write(1);
        if(machine_is_iq80331())        // all interrupts are inputs to chip
                *IOP3XX_PCIIRSR = 0x0f;
 
 
                 * Note: only deal with normal interrupts, not FIQ
                 */
                .macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
-               mov     \irqnr, #0
                ldr     \base, =IOP3XX_REG_ADDR(0x07D8)
                ldr     \irqstat, [\base]               @ Read IINTSRC
-               cmp     \irqstat, #0
-               beq     1001f
-               clz     \irqnr, \irqstat
-               mov     \base, #31
-               subs    \irqnr,\base,\irqnr
-1001:
+               cmp     \irqstat, #0
+               clzne   \irqnr, \irqstat
+               rsbne   \irqnr, \irqnr, #31
                .endm
 
                .macro  disable_fiq
                .endm
 
-               /*
-                * Note: only deal with normal interrupts, not FIQ
-                */
                .macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
-               mov     \irqnr, #0
-               ldr     \base, =IOP3XX_REG_ADDR(0x7A0)
-               ldr     \irqstat, [\base]               @ Read IINTSRC0
-               cmp     \irqstat, #0
-               bne     1002f
-               ldr     \irqstat, [\base, #4]           @ Read IINTSRC1
+               ldr     \base, =IOP3XX_REG_ADDR(0x07C8)
+               ldr     \irqstat, [\base]               @ Read IINTVEC
                cmp     \irqstat, #0
-               beq     1001f
-               clz     \irqnr, \irqstat
-               rsbs    \irqnr,\irqnr,#31   @ recommend by RMK
-               add     \irqnr,\irqnr,#IRQ_IOP331_XINT8
-               b       1001f
-1002:          clz     \irqnr, \irqstat
-               rsbs    \irqnr,\irqnr,#31   @ recommend by RMK
-1001:
+               ldreq   \irqstat, [\base]               @ erratum 63 workaround
+               adds    \irqnr, \irqstat, #1
+               movne   \irqnr, \irqstat, lsr #2
                .endm