/*
* ip27-irq.c: Highlevel interrupt handling for IP27 architecture.
*
* Copyright (C) 1999, 2000 Ralf Baechle (ralf@gnu.org)
* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
* Copyright (C) 1999 - 2001 Kanoj Sarcar
*/
#undef DEBUG
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/timex.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/delay.h>
#include <linux/bitops.h>
#include <asm/bootinfo.h>
#include <asm/io.h>
#include <asm/mipsregs.h>
#include <asm/system.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#include <asm/pci/bridge.h>
#include <asm/sn/addrs.h>
#include <asm/sn/agent.h>
#include <asm/sn/arch.h>
#include <asm/sn/hub.h>
#include <asm/sn/intr.h>
/*
* Linux has a controller-independent x86 interrupt architecture.
* every controller has a 'controller-template', that is used
* by the main code to do the right thing. Each driver-visible
* interrupt source is transparently wired to the apropriate
* controller. Thus drivers need not be aware of the
* interrupt-controller.
*
* Various interrupt controllers we handle: 8259 PIC, SMP IO-APIC,
* PIIX4's internal 8259 PIC and SGI's Visual Workstation Cobalt (IO-)APIC.
* (IO-APICs assumed to be messaging to Pentium local-APICs)
*
* the code is designed to be easily extended with new/different
* interrupt controllers, without having to do assembly magic.
*/
extern asmlinkage void ip27_irq(void);
extern struct bridge_controller *irq_to_bridge[];
extern int irq_to_slot[];
/*
* use these macros to get the encoded nasid and widget id
* from the irq value
*/
#define IRQ_TO_BRIDGE(i) irq_to_bridge[(i)]
#define SLOT_FROM_PCI_IRQ(i) irq_to_slot[i]
static inline int alloc_level(int cpu, int irq)
{
struct hub_data *hub = hub_data(cpu_to_node(cpu));
struct slice_data *si = cpu_data[cpu].data;
int level;
level = find_first_zero_bit(hub->irq_alloc_mask, LEVELS_PER_SLICE);
if (level >= LEVELS_PER_SLICE)
panic("Cpu %d flooded with devices\n", cpu);
__set_bit(level, hub->irq_alloc_mask);
si->level_to_irq[level] = irq;
return level;
}
static inline int find_level(cpuid_t *cpunum, int irq)
{
int cpu, i;
for_each_online_cpu(cpu) {
struct slice_data *si = cpu_data[cpu].data;
for (i = BASE_PCI_IRQ; i < LEVELS_PER_SLICE; i++)
if (si->level_to_irq[i] == irq) {
*cpunum = cpu;
return i;
}
}
panic("Could not identify cpu/level for irq %d\n", irq);
}
/*
* Find first bit set
*/
static int ms1bit(unsigned long x)
{
int b = 0, s;
s = 16; if (x >> 16 == 0) s = 0; b += s; x >>= s;
s = 8; if (x >> 8 == 0) s = 0; b += s; x >>= s;
s = 4; if (x >> 4 == 0) s = 0; b += s; x >>= s;
s = 2; if (x >> 2 == 0) s = 0; b += s; x >>= s;
s = 1; if (x >> 1 == 0) s = 0; b += s;
return b;
}
/*
* This code is unnecessarily complex, because we do IRQF_DISABLED
* intr enabling. Basically, once we grab the set of intrs we need
* to service, we must mask _all_ these interrupts; firstly, to make
* sure the same intr does not intr again, causing recursion that
* can lead to stack overflow. Secondly, we can not just mask the
* one intr we are do_IRQing, because the non-masked intrs in the
* first set might intr again, causing multiple servicings of the
* same intr. This effect is mostly seen for intercpu intrs.
* Kanoj 05.13.00
*/
static void ip27_do_irq_mask0(struct pt_regs *regs)
{
int irq, swlevel;
hubreg_t pend0, mask0;
cpuid_t cpu = smp_processor_id();
int pi_int_mask0 =
(cputoslice(cpu) == 0) ? PI_INT_MASK0_A : PI_INT_MASK0_B;
/* copied from Irix intpend0() */
pend0 = LOCAL_HUB_L(PI_INT_PEND0);
mask0 = LOCAL_HUB_L(pi_int_mask0);
pend0 &= mask0; /* Pick intrs we should look at */
if (!pend0)
return;
swlevel = ms1bit(pend0);
#ifdef CONFIG_SMP
if (pend0 & (1UL << CPU_RESCHED_A_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_RESCHED_A_IRQ);
} else if (pend0 & (1UL << CPU_RESCHED_B_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_RESCHED_B_IRQ);
} else if (pend0 & (1UL << CPU_CALL_A_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_A_IRQ);
smp_call_function_interrupt();
} else if (pend0 & (1UL << CPU_CALL_B_IRQ)) {
LOCAL_HUB_CLR_INTR(CPU_CALL_B_IRQ);
smp_call_function_interrupt();
} else
#endif
{
/* "map" swlevel to irq */
struct slice_data *si = cpu_data[cpu].data;
irq = si->level_to_irq[swlevel];
do_IRQ(irq, regs);
}
LOCAL_HUB_L(PI_INT_PEND0);
}
static void ip27_do_irq_mask1(struct pt_regs *regs)
{
int irq, swlevel;
hubreg_t pend1, mask1;
cpuid_t cpu = smp_processor_id();
int pi_int_mask1 = (cputoslice(cpu) == 0) ? PI_INT_MASK1_A : PI_INT_MASK1_B;
struct slice_data *si = cpu_data[cpu].data;
/* copied from Irix intpend0() */
pend1 = LOCAL_HUB_L(PI_INT_PEND1);
mask1 = LOCAL_HUB_L(pi_int_mask1);
pend1 &= mask1; /* Pick intrs we should look at */
if (!pend1)
return;
swlevel = ms1bit(pend1);
/* "map" swlevel to irq */
irq = si->level_to_irq[swlevel];
LOCAL_HUB_CLR_INTR(swlevel);
do_IRQ(irq, regs);
LOCAL_HUB_L(PI_INT_PEND1);
}
static void ip27_prof_timer(struct pt_regs *regs)
{
panic("CPU %d got a profiling interrupt", smp_processor_id());
}
static void ip27_hub_error(struct pt_regs *regs)
{
panic("CPU %d got a hub error interrupt", smp_processor_id());
}
static int intr_connect_level(int cpu, int bit)
{
nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
struct slice_data *si = cpu_data[cpu].data;
unsigned long flags;
set_bit(bit, si->irq_enable_mask);
local_irq_save(flags);
if (!cputoslice(cpu)) {
REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]);
REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]);
} else {
REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]);
REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]);
}
local_irq_restore(flags);
return 0;
}
static int intr_disconnect_level(int cpu, int bit)
{
nasid_t nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
struct slice_data *si = cpu_data[cpu].data;
clear_bit(bit, si->irq_enable_mask);
if (!cputoslice(cpu)) {
REMOTE_HUB_S(nasid, PI_INT_MASK0_A, si->irq_enable_mask[0]);
REMOTE_HUB_S(nasid, PI_INT_MASK1_A, si->irq_enable_mask[1]);
} else {
REMOTE_HUB_S(nasid, PI_INT_MASK0_B, si->irq_enable_mask[0]);
REMOTE_HUB_S(nasid, PI_INT_MASK1_B, si->irq_enable_mask[1]);
}
return 0;
}
/* Startup one of the (PCI ...) IRQs routes over a bridge. */
static unsigned int startup_bridge_irq(unsigned int irq)
{
struct bridge_controller *bc;
bridgereg_t device;
bridge_t *bridge;
int pin, swlevel;
cpuid_t cpu;
pin = SLOT_FROM_PCI_IRQ(irq);
bc = IRQ_TO_BRIDGE(irq);
bridge = bc->base;
pr_debug("bridge_startup(): irq= 0x%x pin=%d\n", irq, pin);
/*
* "map" irq to a swlevel greater than 6 since the first 6 bits
* of INT_PEND0 are taken
*/
swlevel = find_level(&cpu, irq);
bridge->b_int_addr[pin].addr = (0x20000 | swlevel | (bc->nasid << 8));
bridge->b_int_enable |= (1 << pin);
bridge->b_int_enable |= 0x7ffffe00; /* more stuff in int_enable */
/*
* Enable sending of an interrupt clear packt to the hub on a high to
* low transition of the interrupt pin.
*
* IRIX sets additional bits in the address which are documented as
* reserved in the bridge docs.
*/
bridge->b_int_mode |= (1UL << pin);
/*
* We assume the bridge to have a 1:1 mapping between devices
* (slots) and intr pins.
*/
device = bridge->b_int_device;
device &= ~(7 << (pin*3));
device |= (pin << (pin*3));
bridge->b_int_device = device;
bridge->b_wid_tflush;
return 0; /* Never anything pending. */
}
/* Shutdown one of the (PCI ...) IRQs routes over a bridge. */
static void shutdown_bridge_irq(unsigned int irq)
{
struct bridge_controller *bc = IRQ_TO_BRIDGE(irq);
struct hub_data *hub = hub_data(cpu_to_node(bc->irq_cpu));
bridge_t *bridge = bc->base;
int pin, swlevel;
cpuid_t cpu;
pr_debug("bridge_shutdown: irq 0x%x\n", irq);
pin = SLOT_FROM_PCI_IRQ(irq);
/*
* map irq to a swlevel greater than 6 since the first 6 bits
* of INT_PEND0 are taken
*/
swlevel = find_level(&cpu, irq);
intr_disconnect_level(cpu, swlevel);
__clear_bit(swlevel, hub->irq_alloc_mask);
bridge->b_int_enable &= ~(1 << pin);
bridge->b_wid_tflush;
}
static inline void enable_bridge_irq(unsigned int irq)
{
cpuid_t cpu;
int swlevel;
swlevel = find_level(&cpu, irq); /* Criminal offence */
intr_connect_level(cpu, swlevel);
}
static inline void disable_bridge_irq(unsigned int irq)
{
cpuid_t cpu;
int swlevel;
swlevel = find_level(&cpu, irq); /* Criminal offence */
intr_disconnect_level(cpu, swlevel);
}
static void mask_and_ack_bridge_irq(unsigned int irq)
{
disable_bridge_irq(irq);
}
static void end_bridge_irq(unsigned int irq)
{
if (!(irq_desc[irq].status & (IRQ_DISABLED|IRQ_INPROGRESS)) &&
irq_desc[irq].action)
enable_bridge_irq(irq);
}
static struct irq_chip bridge_irq_type = {
.typename = "bridge",
.startup = startup_bridge_irq,
.shutdown = shutdown_bridge_irq,
.enable = enable_bridge_irq,
.disable = disable_bridge_irq,
.ack = mask_and_ack_bridge_irq,
.end = end_bridge_irq,
};
static unsigned long irq_map[NR_IRQS / BITS_PER_LONG];
int allocate_irqno(void)
{
int irq;
again:
irq = find_first_zero_bit(irq_map, NR_IRQS);
if (irq >= NR_IRQS)
return -ENOSPC;
if (test_and_set_bit(irq, irq_map))
goto again;
return irq;
}
void free_irqno(unsigned int irq)
{
clear_bit(irq, irq_map);
}
void __devinit register_bridge_irq(unsigned int irq)
{
irq_desc[irq].status = IRQ_DISABLED;
irq_desc[irq].action = 0;
irq_desc[irq].depth = 1;
irq_desc[irq].chip = &bridge_irq_type;
}
int __devinit request_bridge_irq(struct bridge_controller *bc)
{
int irq = allocate_irqno();
int swlevel, cpu;
nasid_t nasid;
if (irq < 0)
return irq;
/*
* "map" irq to a swlevel greater than 6 since the first 6 bits
* of INT_PEND0 are taken
*/
cpu = bc->irq_cpu;
swlevel = alloc_level(cpu, irq);
if (unlikely(swlevel < 0)) {
free_irqno(irq);
return -EAGAIN;
}
/* Make sure it's not already pending when we connect it. */
nasid = COMPACT_TO_NASID_NODEID(cpu_to_node(cpu));
REMOTE_HUB_CLR_INTR(nasid, swlevel);
intr_connect_level(cpu, swlevel);
register_bridge_irq(irq);
return irq;
}
extern void ip27_rt_timer_interrupt(struct pt_regs *regs);
asmlinkage void plat_irq_dispatch(struct pt_regs *regs)
{
unsigned long pending = read_c0_cause() & read_c0_status();
if (pending & CAUSEF_IP4)
ip27_rt_timer_interrupt(regs);
else if (pending & CAUSEF_IP2) /* PI_INT_PEND_0 or CC_PEND_{A|B} */
ip27_do_irq_mask0(regs);
else if (pending & CAUSEF_IP3) /* PI_INT_PEND_1 */
ip27_do_irq_mask1(regs);
else if (pending & CAUSEF_IP5)
ip27_prof_timer(regs);
else if (pending & CAUSEF_IP6)
ip27_hub_error(regs);
}
void __init arch_init_irq(void)
{
}
void install_ipi(void)
{
int slice = LOCAL_HUB_L(PI_CPU_NUM);
int cpu = smp_processor_id();
struct slice_data *si = cpu_data[cpu].data;
struct hub_data *hub = hub_data(cpu_to_node(cpu));
int resched, call;
resched = CPU_RESCHED_A_IRQ + slice;
__set_bit(resched, hub->irq_alloc_mask);
__set_bit(resched, si->irq_enable_mask);
LOCAL_HUB_CLR_INTR(resched);
call = CPU_CALL_A_IRQ + slice;
__set_bit(call, hub->irq_alloc_mask);
__set_bit(call, si->irq_enable_mask);
LOCAL_HUB_CLR_INTR(call);
if (slice == 0) {
LOCAL_HUB_S(PI_INT_MASK0_A, si->irq_enable_mask[0]);
LOCAL_HUB_S(PI_INT_MASK1_A, si->irq_enable_mask[1]);
} else {
LOCAL_HUB_S(PI_INT_MASK0_B, si->irq_enable_mask[0]);
LOCAL_HUB_S(PI_INT_MASK1_B, si->irq_enable_mask[1]);
}
}
