diff options
Diffstat (limited to 'arch/mips/sgi-ip27/ip27-irq-pci.c')
| -rw-r--r-- | arch/mips/sgi-ip27/ip27-irq-pci.c | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/arch/mips/sgi-ip27/ip27-irq-pci.c b/arch/mips/sgi-ip27/ip27-irq-pci.c new file mode 100644 index 000000000..2a1c40784 --- /dev/null +++ b/arch/mips/sgi-ip27/ip27-irq-pci.c @@ -0,0 +1,265 @@ +/* + * 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/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/smp.h> +#include <linux/random.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/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 appropriate + * 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 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", 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", irq); +} + +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; + + set_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; +} + +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(struct irq_data *d) +{ + struct bridge_controller *bc; + bridgereg_t device; + bridge_t *bridge; + int pin, swlevel; + cpuid_t cpu; + + pin = SLOT_FROM_PCI_IRQ(d->irq); + bc = IRQ_TO_BRIDGE(d->irq); + bridge = bc->base; + + pr_debug("bridge_startup(): irq= 0x%x pin=%d\n", d->irq, pin); + /* + * "map" irq to a swlevel greater than 6 since the first 6 bits + * of INT_PEND0 are taken + */ + swlevel = find_level(&cpu, d->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; + + intr_connect_level(cpu, swlevel); + + return 0; /* Never anything pending. */ +} + +/* Shutdown one of the (PCI ...) IRQs routes over a bridge. */ +static void shutdown_bridge_irq(struct irq_data *d) +{ + struct bridge_controller *bc = IRQ_TO_BRIDGE(d->irq); + bridge_t *bridge = bc->base; + int pin, swlevel; + cpuid_t cpu; + + pr_debug("bridge_shutdown: irq 0x%x\n", d->irq); + pin = SLOT_FROM_PCI_IRQ(d->irq); + + /* + * map irq to a swlevel greater than 6 since the first 6 bits + * of INT_PEND0 are taken + */ + swlevel = find_level(&cpu, d->irq); + intr_disconnect_level(cpu, swlevel); + + bridge->b_int_enable &= ~(1 << pin); + bridge->b_wid_tflush; +} + +static inline void enable_bridge_irq(struct irq_data *d) +{ + cpuid_t cpu; + int swlevel; + + swlevel = find_level(&cpu, d->irq); /* Criminal offence */ + intr_connect_level(cpu, swlevel); +} + +static inline void disable_bridge_irq(struct irq_data *d) +{ + cpuid_t cpu; + int swlevel; + + swlevel = find_level(&cpu, d->irq); /* Criminal offence */ + intr_disconnect_level(cpu, swlevel); +} + +static struct irq_chip bridge_irq_type = { + .name = "bridge", + .irq_startup = startup_bridge_irq, + .irq_shutdown = shutdown_bridge_irq, + .irq_mask = disable_bridge_irq, + .irq_unmask = enable_bridge_irq, +}; + +void register_bridge_irq(unsigned int irq) +{ + irq_set_chip_and_handler(irq, &bridge_irq_type, handle_level_irq); +} + +int 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; +} |