[ARM] 3825/1: iop3xx: use cp6 enable/disable macros

Add CP6 enable/disable sequences to the timekeeping code and the IRQ
code.  As a result, we can't depend on CP6 access being enabled when
we enter get_irqnr_and_base anymore, so switch the latter over to
using memory-mapped accesses for now.

Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-iop32x/irq.c

@@ -27,12 +27,16 @@ static u32 iop321_mask /* = 0 */;
 
 static inline void intctl_write(u32 val)
 {
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6,0,%0,c0,c0,0"::"r" (val));
+	iop3xx_cp6_disable();
 }
 
 static inline void intstr_write(u32 val)
 {
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6,0,%0,c4,c0,0"::"r" (val));
+	iop3xx_cp6_disable();
 }
 
 static void
@@ -61,24 +65,7 @@ struct irq_chip ext_chip = {
 
 void __init iop321_init_irq(void)
 {
-	unsigned int i, tmp;
-
-	/* Enable access to coprocessor 6 for dealing with IRQs.
-	 * From RMK:
-	 * Basically, the Intel documentation here is poor.  It appears that
-	 * you need to set the bit to be able to access the coprocessor from
-	 * SVC mode.  Whether that allows access from user space or not is
-	 * unclear.
-	 */
-	asm volatile (
-		"mrc p15, 0, %0, c15, c1, 0\n\t"
-		"orr %0, %0, %1\n\t"
-		"mcr p15, 0, %0, c15, c1, 0\n\t"
-		/* The action is delayed, so we have to do this: */
-		"mrc p15, 0, %0, c15, c1, 0\n\t"
-		"mov %0, %0\n\t"
-		"sub pc, pc, #4"
-		: "=r" (tmp) : "i" (1 << 6) );
+	unsigned int i;
 
 	intctl_write(0);		// disable all interrupts
 	intstr_write(0);		// treat all as IRQ

arch/arm/mach-iop33x/irq.c

@@ -28,25 +28,33 @@ static u32 iop331_mask1 = 0;
 static inline void intctl_write0(u32 val)
 {
     // INTCTL0
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6,0,%0,c0,c0,0"::"r" (val));
+	iop3xx_cp6_disable();
 }
 
 static inline void intctl_write1(u32 val)
 {
     // INTCTL1
+	iop3xx_cp6_enable();
     asm volatile("mcr p6,0,%0,c1,c0,0"::"r" (val));
+	iop3xx_cp6_disable();
 }
 
 static inline void intstr_write0(u32 val)
 {
     // INTSTR0
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6,0,%0,c2,c0,0"::"r" (val));
+	iop3xx_cp6_disable();
 }
 
 static inline void intstr_write1(u32 val)
 {
     // INTSTR1
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6,0,%0,c3,c0,0"::"r" (val));
+	iop3xx_cp6_disable();
 }
 
 static void
@@ -93,24 +101,7 @@ struct irq_chip iop331_irqchip2 = {
 
 void __init iop331_init_irq(void)
 {
-	unsigned int i, tmp;
-
-	/* Enable access to coprocessor 6 for dealing with IRQs.
-	 * From RMK:
-	 * Basically, the Intel documentation here is poor.  It appears that
-	 * you need to set the bit to be able to access the coprocessor from
-	 * SVC mode.  Whether that allows access from user space or not is
-	 * unclear.
-	 */
-	asm volatile (
-		"mrc p15, 0, %0, c15, c1, 0\n\t"
-		"orr %0, %0, %1\n\t"
-		"mcr p15, 0, %0, c15, c1, 0\n\t"
-		/* The action is delayed, so we have to do this: */
-		"mrc p15, 0, %0, c15, c1, 0\n\t"
-		"mov %0, %0\n\t"
-		"sub pc, pc, #4"
-		: "=r" (tmp) : "i" (1 << 6) );
+	unsigned int i;
 
 	intctl_write0(0);		// disable all interrupts
     	intctl_write1(0);

arch/arm/plat-iop/time.c

@@ -51,7 +51,9 @@ iop3xx_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
 {
 	write_seqlock(&xtime_lock);
 
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6, 0, %0, c6, c1, 0" : : "r" (1));
+	iop3xx_cp6_disable();
 
 	while ((signed long)(next_jiffy_time - *IOP3XX_TU_TCR1)
 							>= ticks_per_jiffy) {
@@ -85,10 +87,12 @@ void __init iop3xx_init_time(unsigned long tick_rate)
 	 * We use timer 0 for our timer interrupt, and timer 1 as
 	 * monotonic counter for tracking missed jiffies.
 	 */
+	iop3xx_cp6_enable();
 	asm volatile("mcr p6, 0, %0, c4, c1, 0" : : "r" (ticks_per_jiffy - 1));
 	asm volatile("mcr p6, 0, %0, c0, c1, 0" : : "r" (timer_ctl));
 	asm volatile("mcr p6, 0, %0, c5, c1, 0" : : "r" (0xffffffff));
 	asm volatile("mcr p6, 0, %0, c1, c1, 0" : : "r" (timer_ctl));
+	iop3xx_cp6_disable();
 
 	setup_irq(IRQ_IOP3XX_TIMER0, &iop3xx_timer_irq);
 }

include/asm-arm/arch-iop32x/entry-macro.S

@@ -17,7 +17,8 @@
 		 */
 		.macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
 		mov     \irqnr, #0
-		mrc     p6, 0, \irqstat, c8, c0, 0      @ Read IINTSRC
+		ldr	\base, =IOP3XX_REG_ADDR(0x07D8)
+		ldr	\irqstat, [\base]		@ Read IINTSRC
 		cmp     \irqstat, #0
 		beq     1001f
 		clz     \irqnr, \irqstat

include/asm-arm/arch-iop33x/entry-macro.S

@@ -17,10 +17,11 @@
 		 */
 		.macro  get_irqnr_and_base, irqnr, irqstat, base, tmp
 		mov     \irqnr, #0
-		mrc     p6, 0, \irqstat, c4, c0, 0      @ Read IINTSRC0
+		ldr	\base, =IOP3XX_REG_ADDR(0x7A0)
+		ldr	\irqstat, [\base]		@ Read IINTSRC0
 		cmp     \irqstat, #0
 		bne     1002f
-		mrc     p6, 0, \irqstat, c5, c0, 0      @ Read IINTSRC1
+		ldr	\irqstat, [\base, #4]		@ Read IINTSRC1
 		cmp	\irqstat, #0
 		beq	1001f
 		clz	\irqnr, \irqstat