open_pic.c

microwindows移植到S3C44B0的源码

	 * the ISU array is setup in chrp_pci.c in ibm_add_bridges
	 * as a result
	 * -- tgall
         */

	/* basically each ISU is a bus, and this assumes that
	 * open_pic_isu_count interrupts per bus are possible 
	 * ISU == Interrupt Source
	 */
	NumSources = NumISUs * 0x10;
	openpic_vec_ipi = NumSources + open_pic_irq_offset;
	openpic_vec_timer = openpic_vec_ipi + OPENPIC_NUM_IPI; 
	openpic_vec_spurious = openpic_vec_timer + OPENPIC_NUM_TIMERS;
}

static inline void openpic_reset(void)
{
	openpic_setfield(&OpenPIC->Global.Global_Configuration0,
			 OPENPIC_CONFIG_RESET);
}

static inline void openpic_enable_8259_pass_through(void)
{
	openpic_clearfield(&OpenPIC->Global.Global_Configuration0,
			   OPENPIC_CONFIG_8259_PASSTHROUGH_DISABLE);
}

static void openpic_disable_8259_pass_through(void)
{
	openpic_setfield(&OpenPIC->Global.Global_Configuration0,
			 OPENPIC_CONFIG_8259_PASSTHROUGH_DISABLE);
}

/*
 *  Find out the current interrupt
 */
static u_int openpic_irq(void)
{
	u_int vec;
	DECL_THIS_CPU;

	CHECK_THIS_CPU;
	vec = openpic_readfield(&OpenPIC->THIS_CPU.Interrupt_Acknowledge,
				OPENPIC_VECTOR_MASK);
	return vec;
}

static void openpic_eoi(void)
{
	DECL_THIS_CPU;

	CHECK_THIS_CPU;
	openpic_write(&OpenPIC->THIS_CPU.EOI, 0);
	/* Handle PCI write posting */
	(void)openpic_read(&OpenPIC->THIS_CPU.EOI);
}


static inline u_int openpic_get_priority(void)
{
	DECL_THIS_CPU;

	CHECK_THIS_CPU;
	return openpic_readfield(&OpenPIC->THIS_CPU.Current_Task_Priority,
				 OPENPIC_CURRENT_TASK_PRIORITY_MASK);
}

static void openpic_set_priority(u_int pri)
{
	DECL_THIS_CPU;

	CHECK_THIS_CPU;
	check_arg_pri(pri);
	openpic_writefield(&OpenPIC->THIS_CPU.Current_Task_Priority,
			   OPENPIC_CURRENT_TASK_PRIORITY_MASK, pri);
}

/*
 *  Get/set the spurious vector
 */
static inline u_int openpic_get_spurious(void)
{
	return openpic_readfield(&OpenPIC->Global.Spurious_Vector,
				 OPENPIC_VECTOR_MASK);
}

static void openpic_set_spurious(u_int vec)
{
	check_arg_vec(vec);
	openpic_writefield(&OpenPIC->Global.Spurious_Vector, OPENPIC_VECTOR_MASK,
			   vec);
}

/*
 * Convert a cpu mask from logical to physical cpu numbers.
 */
static inline u32 physmask(u32 cpumask)
{
	int i;
	u32 mask = 0;

	for (i = 0; i < smp_num_cpus; ++i, cpumask >>= 1)
		mask |= (cpumask & 1) << get_hard_smp_processor_id(i);
	return mask;
}

void openpic_init_processor(u_int cpumask)
{
	openpic_write(&OpenPIC->Global.Processor_Initialization,
		      physmask(cpumask));
}

#ifdef CONFIG_SMP
/*
 *  Initialize an interprocessor interrupt (and disable it)
 *
 *  ipi: OpenPIC interprocessor interrupt number
 *  pri: interrupt source priority
 *  vec: the vector it will produce
 */
static void __init openpic_initipi(u_int ipi, u_int pri, u_int vec)
{
	check_arg_ipi(ipi);
	check_arg_pri(pri);
	check_arg_vec(vec);
	openpic_safe_writefield_IPI(&OpenPIC->Global.IPI_Vector_Priority(ipi),
				OPENPIC_PRIORITY_MASK | OPENPIC_VECTOR_MASK,
				(pri << OPENPIC_PRIORITY_SHIFT) | vec);
}

/*
 *  Send an IPI to one or more CPUs
 *  
 *  Externally called, however, it takes an IPI number (0...OPENPIC_NUM_IPI)
 *  and not a system-wide interrupt number
 */
void openpic_cause_IPI(u_int ipi, u_int cpumask)
{
	DECL_THIS_CPU;

	CHECK_THIS_CPU;
	check_arg_ipi(ipi);
	openpic_write(&OpenPIC->THIS_CPU.IPI_Dispatch(ipi),
		      physmask(cpumask));
}

void openpic_request_IPIs(void)
{
	int i;
	
	/*
	 * Make sure this matches what is defined in smp.c for 
	 * smp_message_{pass|recv}() or what shows up in 
	 * /proc/interrupts will be wrong!!! --Troy */
	
	if (OpenPIC == NULL)
		return;

	request_irq(openpic_vec_ipi,
		    openpic_ipi_action, 0, "IPI0 (call function)", 0);
	request_irq(openpic_vec_ipi+1,
		    openpic_ipi_action, 0, "IPI1 (reschedule)", 0);
	request_irq(openpic_vec_ipi+2,
		    openpic_ipi_action, 0, "IPI2 (invalidate tlb)", 0);
	request_irq(openpic_vec_ipi+3,
		    openpic_ipi_action, 0, "IPI3 (xmon break)", 0);

	for ( i = 0; i < OPENPIC_NUM_IPI ; i++ )
		openpic_enable_ipi(openpic_vec_ipi+i);
}

/*
 * Do per-cpu setup for SMP systems.
 *
 * Get IPI's working and start taking interrupts.
 *   -- Cort
 */
static spinlock_t openpic_setup_lock __initdata = SPIN_LOCK_UNLOCKED;

void __init do_openpic_setup_cpu(void)
{
#ifdef CONFIG_IRQ_ALL_CPUS
 	int i;
	u32 msk = 1 << hard_smp_processor_id();
#endif

	spin_lock(&openpic_setup_lock);

#ifdef CONFIG_IRQ_ALL_CPUS
 	/* let the openpic know we want intrs. default affinity
 	 * is 0xffffffff until changed via /proc
 	 * That's how it's done on x86. If we want it differently, then
 	 * we should make sure we also change the default values of irq_affinity
 	 * in irq.c.
 	 */
 	for (i = 0; i < NumSources ; i++)
		openpic_mapirq(i, openpic_read(&GET_ISU(i).Destination) | msk);
#endif /* CONFIG_IRQ_ALL_CPUS */
 	openpic_set_priority(0);

	spin_unlock(&openpic_setup_lock);
}
#endif /* CONFIG_SMP */

/*
 *  Initialize a timer interrupt (and disable it)
 *
 *  timer: OpenPIC timer number
 *  pri: interrupt source priority
 *  vec: the vector it will produce
 */
static void __init openpic_inittimer(u_int timer, u_int pri, u_int vec)
{
	check_arg_timer(timer);
	check_arg_pri(pri);
	check_arg_vec(vec);
	openpic_safe_writefield(&OpenPIC->Global.Timer[timer].Vector_Priority,
				OPENPIC_PRIORITY_MASK | OPENPIC_VECTOR_MASK,
				(pri << OPENPIC_PRIORITY_SHIFT) | vec);
}

/*
 *  Map a timer interrupt to one or more CPUs
 */
static void __init openpic_maptimer(u_int timer, u_int cpumask)
{
	check_arg_timer(timer);
	openpic_write(&OpenPIC->Global.Timer[timer].Destination,
		      physmask(cpumask));
}


/*
 *
 * All functions below take an offset'ed irq argument
 *
 */


/*
 *  Enable/disable an external interrupt source
 *
 *  Externally called, irq is an offseted system-wide interrupt number
 */
static void openpic_enable_irq(u_int irq)
{
	unsigned int loops = 100000;
	check_arg_irq(irq);

	openpic_clearfield(&GET_ISU(irq - open_pic_irq_offset).Vector_Priority, OPENPIC_MASK);
	/* make sure mask gets to controller before we return to user */
	do {
		if (!loops--) {
			printk(KERN_ERR "openpic_enable_irq timeout\n");
			break;
		}

		mb(); /* sync is probably useless here */
	} while(openpic_readfield(&GET_ISU(irq - open_pic_irq_offset).Vector_Priority,
			OPENPIC_MASK));
}

static void openpic_disable_irq(u_int irq)
{
	u32 vp;
	unsigned int loops = 100000;
	
	check_arg_irq(irq);

	openpic_setfield(&GET_ISU(irq - open_pic_irq_offset).Vector_Priority, OPENPIC_MASK);
	/* make sure mask gets to controller before we return to user */
	do {
		if (!loops--) {
			printk(KERN_ERR "openpic_disable_irq timeout\n");
			break;
		}

		mb();  /* sync is probably useless here */
		vp = openpic_readfield(&GET_ISU(irq - open_pic_irq_offset).Vector_Priority,
    			OPENPIC_MASK | OPENPIC_ACTIVITY);
	} while((vp & OPENPIC_ACTIVITY) && !(vp & OPENPIC_MASK));
}

#ifdef CONFIG_SMP
/*
 *  Enable/disable an IPI interrupt source
 *  
 *  Externally called, irq is an offseted system-wide interrupt number
 */
void openpic_enable_ipi(u_int irq)
{
	irq -= openpic_vec_ipi;
	check_arg_ipi(irq);
	openpic_clearfield_IPI(&OpenPIC->Global.IPI_Vector_Priority(irq), OPENPIC_MASK);

}
void openpic_disable_ipi(u_int irq)
{
   /* NEVER disable an IPI... that's just plain wrong! */
}

#endif

/*
 *  Initialize an interrupt source (and disable it!)
 *
 *  irq: OpenPIC interrupt number
 *  pri: interrupt source priority
 *  vec: the vector it will produce
 *  pol: polarity (1 for positive, 0 for negative)
 *  sense: 1 for level, 0 for edge
 */
static void openpic_initirq(u_int irq, u_int pri, u_int vec, int pol, int sense)
{
	openpic_safe_writefield(&GET_ISU(irq).Vector_Priority,
				OPENPIC_PRIORITY_MASK | OPENPIC_VECTOR_MASK |
				OPENPIC_SENSE_MASK | OPENPIC_POLARITY_MASK,
				(pri << OPENPIC_PRIORITY_SHIFT) | vec |
				(pol ? OPENPIC_POLARITY_POSITIVE :
			    		OPENPIC_POLARITY_NEGATIVE) |
				(sense ? OPENPIC_SENSE_LEVEL : OPENPIC_SENSE_EDGE));
}

/*
 *  Map an interrupt source to one or more CPUs
 */
static void openpic_mapirq(u_int irq, u_int physmask)
{
	openpic_write(&GET_ISU(irq).Destination, physmask);
}

/*
 *  Set the sense for an interrupt source (and disable it!)
 *
 *  sense: 1 for level, 0 for edge
 */
static inline void openpic_set_sense(u_int irq, int sense)
{
	openpic_safe_writefield(&GET_ISU(irq).Vector_Priority,
				OPENPIC_SENSE_LEVEL,
				(sense ? OPENPIC_SENSE_LEVEL : 0));
}

/* No spinlocks, should not be necessary with the OpenPIC
 * (1 register = 1 interrupt and we have the desc lock).
 */
static void openpic_ack_irq(unsigned int irq_nr)
{
}

static void openpic_end_irq(unsigned int irq_nr)
{
	if ((irq_desc[irq_nr].status & IRQ_LEVEL) != 0)
		openpic_eoi();
}

static void openpic_set_affinity(unsigned int irq_nr, unsigned long cpumask)
{
	openpic_mapirq(irq_nr - open_pic_irq_offset, physmask(cpumask));
}

#ifdef CONFIG_SMP
static void openpic_ack_ipi(unsigned int irq_nr)
{
}

static void openpic_end_ipi(unsigned int irq_nr)
{
	/* IPIs are marked IRQ_PER_CPU. This has the side effect of
	 * preventing the IRQ_PENDING/IRQ_INPROGRESS logic from
	 * applying to them. We EOI them late to avoid re-entering.
	 * however, I'm wondering if we could simply let them have the
	 * SA_INTERRUPT flag and let them execute with all interrupts OFF.
	 * This would have the side effect of either running cross-CPU
	 * functions with interrupts off, or we can re-enable them explicitely
	 * with a __sti() in smp_call_function_interrupt(), since
	 * smp_call_function() is protected by a spinlock.
	 * Or maybe we shouldn't set the IRQ_PER_CPU flag on cross-CPU
	 * function calls IPI at all but that would make a special case.
	 */
	openpic_eoi();
}

static void openpic_ipi_action(int cpl, void *dev_id, struct pt_regs *regs)
{
	smp_message_recv(cpl-openpic_vec_ipi, regs);
}

#endif /* CONFIG_SMP */

int openpic_get_irq(struct pt_regs *regs)
{
	extern int i8259_irq(int cpu);

	int irq = openpic_irq();

	/* Management of the cascade should be moved out of here */
        if (open_pic_irq_offset && irq == open_pic_irq_offset)
        {
                /*
                 * This magic address generates a PCI IACK cycle.
                 */
		if ( chrp_int_ack_special )
			irq = *chrp_int_ack_special;
		else
			irq = i8259_irq( smp_processor_id() );
		openpic_eoi();
        }
	if (irq == openpic_vec_spurious)
		irq = -1;
	return irq;
}