/* * 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/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/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(void) { 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); } LOCAL_HUB_L(PI_INT_PEND0); } static void ip27_do_irq_mask1(void) { 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); LOCAL_HUB_L(PI_INT_PEND1); } static void ip27_prof_timer(void) { panic("CPU %d got a profiling interrupt", smp_processor_id()); } static void ip27_hub_error(void) { 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; 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(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; 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(unsigned int irq) { struct bridge_controller *bc = IRQ_TO_BRIDGE(irq); 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); 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 struct irq_chip bridge_irq_type = { .name = "bridge", .startup = startup_bridge_irq, .shutdown = shutdown_bridge_irq, .ack = disable_bridge_irq, .mask = disable_bridge_irq, .mask_ack = disable_bridge_irq, .unmask = enable_bridge_irq, }; void __devinit register_bridge_irq(unsigned int irq) { set_irq_chip_and_handler(irq, &bridge_irq_type, handle_level_irq); } 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; } asmlinkage void plat_irq_dispatch(void) { unsigned long pending = read_c0_cause() & read_c0_status(); extern unsigned int rt_timer_irq; if (pending & CAUSEF_IP4) do_IRQ(rt_timer_irq); else if (pending & CAUSEF_IP2) /* PI_INT_PEND_0 or CC_PEND_{A|B} */ ip27_do_irq_mask0(); else if (pending & CAUSEF_IP3) /* PI_INT_PEND_1 */ ip27_do_irq_mask1(); else if (pending & CAUSEF_IP5) ip27_prof_timer(); else if (pending & CAUSEF_IP6) ip27_hub_error(); } 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]); } }