diff options
| -rw-r--r-- | arch/metag/include/asm/irq.h | 32 | ||||
| -rw-r--r-- | arch/metag/include/asm/irqflags.h | 94 | ||||
| -rw-r--r-- | arch/metag/kernel/irq.c | 318 |
3 files changed, 444 insertions, 0 deletions
diff --git a/arch/metag/include/asm/irq.h b/arch/metag/include/asm/irq.h new file mode 100644 index 0000000..be0c8f3 --- /dev/null +++ b/arch/metag/include/asm/irq.h @@ -0,0 +1,32 @@ +#ifndef __ASM_METAG_IRQ_H +#define __ASM_METAG_IRQ_H + +#ifdef CONFIG_4KSTACKS +extern void irq_ctx_init(int cpu); +extern void irq_ctx_exit(int cpu); +# define __ARCH_HAS_DO_SOFTIRQ +#else +# define irq_ctx_init(cpu) do { } while (0) +# define irq_ctx_exit(cpu) do { } while (0) +#endif + +void tbi_startup_interrupt(int); +void tbi_shutdown_interrupt(int); + +struct pt_regs; + +int tbisig_map(unsigned int hw); +extern void do_IRQ(int irq, struct pt_regs *regs); + +#ifdef CONFIG_METAG_SUSPEND_MEM +int traps_save_context(void); +int traps_restore_context(void); +#endif + +#include <asm-generic/irq.h> + +#ifdef CONFIG_HOTPLUG_CPU +extern void migrate_irqs(void); +#endif + +#endif /* __ASM_METAG_IRQ_H */ diff --git a/arch/metag/include/asm/irqflags.h b/arch/metag/include/asm/irqflags.h new file mode 100644 index 0000000..cba5e13 --- /dev/null +++ b/arch/metag/include/asm/irqflags.h @@ -0,0 +1,94 @@ +/* + * IRQ flags handling + * + * This file gets included from lowlevel asm headers too, to provide + * wrapped versions of the local_irq_*() APIs, based on the + * raw_local_irq_*() functions from the lowlevel headers. + */ +#ifndef _ASM_IRQFLAGS_H +#define _ASM_IRQFLAGS_H + +#ifndef __ASSEMBLY__ + +#include <asm/core_reg.h> +#include <asm/metag_regs.h> + +#define INTS_OFF_MASK TXSTATI_BGNDHALT_BIT + +#ifdef CONFIG_SMP +extern unsigned int get_trigger_mask(void); +#else + +extern unsigned int global_trigger_mask; + +static inline unsigned int get_trigger_mask(void) +{ + return global_trigger_mask; +} +#endif + +static inline unsigned long arch_local_save_flags(void) +{ + return __core_reg_get(TXMASKI); +} + +static inline int arch_irqs_disabled_flags(unsigned long flags) +{ + return (flags & ~INTS_OFF_MASK) == 0; +} + +static inline int arch_irqs_disabled(void) +{ + unsigned long flags = arch_local_save_flags(); + + return arch_irqs_disabled_flags(flags); +} + +static inline unsigned long __irqs_disabled(void) +{ + /* + * We shouldn't enable exceptions if they are not already + * enabled. This is required for chancalls to work correctly. + */ + return arch_local_save_flags() & INTS_OFF_MASK; +} + +/* + * For spinlocks, etc: + */ +static inline unsigned long arch_local_irq_save(void) +{ + unsigned long flags = __irqs_disabled(); + + asm volatile("SWAP %0,TXMASKI\n" : "=r" (flags) : "0" (flags) + : "memory"); + + return flags; +} + +static inline void arch_local_irq_restore(unsigned long flags) +{ + asm volatile("MOV TXMASKI,%0\n" : : "r" (flags) : "memory"); +} + +static inline void arch_local_irq_disable(void) +{ + unsigned long flags = __irqs_disabled(); + + asm volatile("MOV TXMASKI,%0\n" : : "r" (flags) : "memory"); +} + +static inline void arch_local_irq_enable(void) +{ +#ifdef CONFIG_SMP + preempt_disable(); + arch_local_irq_restore(get_trigger_mask()); + preempt_enable_no_resched(); +#else + arch_local_irq_restore(get_trigger_mask()); +#endif +} + +#endif /* (__ASSEMBLY__) */ + +#endif /* !(_ASM_IRQFLAGS_H) */ diff --git a/arch/metag/kernel/irq.c b/arch/metag/kernel/irq.c new file mode 100644 index 0000000..7c04349 --- /dev/null +++ b/arch/metag/kernel/irq.c @@ -0,0 +1,318 @@ +/* + * Linux/Meta general interrupt handling code + * + */ + +#include <linux/kernel.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/irqdomain.h> +#include <linux/ratelimit.h> + +#include <asm/core_reg.h> +#include <asm/mach/arch.h> +#include <asm/uaccess.h> + +#ifdef CONFIG_4KSTACKS +union irq_ctx { + struct thread_info tinfo; + u32 stack[THREAD_SIZE/sizeof(u32)]; +}; + +static union irq_ctx *hardirq_ctx[NR_CPUS] __read_mostly; +static union irq_ctx *softirq_ctx[NR_CPUS] __read_mostly; +#endif + +struct irq_domain *root_domain; + +static unsigned int startup_meta_irq(struct irq_data *data) +{ + tbi_startup_interrupt(data->hwirq); + return 0; +} + +static void shutdown_meta_irq(struct irq_data *data) +{ + tbi_shutdown_interrupt(data->hwirq); +} + +void do_IRQ(int irq, struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); +#ifdef CONFIG_4KSTACKS + struct irq_desc *desc; + union irq_ctx *curctx, *irqctx; + u32 *isp; +#endif + + irq_enter(); + + irq = irq_linear_revmap(root_domain, irq); + +#ifdef CONFIG_DEBUG_STACKOVERFLOW + /* Debugging check for stack overflow: is there less than 1KB free? */ + { + unsigned long sp; + + sp = __core_reg_get(A0StP); + sp &= THREAD_SIZE - 1; + + if (unlikely(sp > (THREAD_SIZE - 1024))) + pr_err("Stack overflow in do_IRQ: %ld\n", sp); + } +#endif + + +#ifdef CONFIG_4KSTACKS + curctx = (union irq_ctx *) current_thread_info(); + irqctx = hardirq_ctx[smp_processor_id()]; + + /* + * this is where we switch to the IRQ stack. However, if we are + * already using the IRQ stack (because we interrupted a hardirq + * handler) we can't do that and just have to keep using the + * current stack (which is the irq stack already after all) + */ + if (curctx != irqctx) { + /* build the stack frame on the IRQ stack */ + isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); + irqctx->tinfo.task = curctx->tinfo.task; + + /* + * Copy the softirq bits in preempt_count so that the + * softirq checks work in the hardirq context. + */ + irqctx->tinfo.preempt_count = + (irqctx->tinfo.preempt_count & ~SOFTIRQ_MASK) | + (curctx->tinfo.preempt_count & SOFTIRQ_MASK); + + desc = irq_to_desc(irq); + + asm volatile ( + "MOV D0.5,%0\n" + "MOV D1Ar1,%1\n" + "MOV D1RtP,%2\n" + "MOV D0Ar2,%3\n" + "SWAP A0StP,D0.5\n" + "SWAP PC,D1RtP\n" + "MOV A0StP,D0.5\n" + : + : "r" (isp), "r" (irq), "r" (desc->handle_irq), + "r" (desc) + : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", + "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", + "D0.5" + ); + } else +#endif + generic_handle_irq(irq); + + irq_exit(); + + set_irq_regs(old_regs); +} + +#ifdef CONFIG_4KSTACKS + +static char softirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; + +static char hardirq_stack[NR_CPUS * THREAD_SIZE] __page_aligned_bss; + +/* + * allocate per-cpu stacks for hardirq and for softirq processing + */ +void irq_ctx_init(int cpu) +{ + union irq_ctx *irqctx; + + if (hardirq_ctx[cpu]) + return; + + irqctx = (union irq_ctx *) &hardirq_stack[cpu * THREAD_SIZE]; + irqctx->tinfo.task = NULL; + irqctx->tinfo.exec_domain = NULL; + irqctx->tinfo.cpu = cpu; + irqctx->tinfo.preempt_count = HARDIRQ_OFFSET; + irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); + + hardirq_ctx[cpu] = irqctx; + + irqctx = (union irq_ctx *) &softirq_stack[cpu * THREAD_SIZE]; + irqctx->tinfo.task = NULL; + irqctx->tinfo.exec_domain = NULL; + irqctx->tinfo.cpu = cpu; + irqctx->tinfo.preempt_count = 0; + irqctx->tinfo.addr_limit = MAKE_MM_SEG(0); + + softirq_ctx[cpu] = irqctx; + + pr_info("CPU %u irqstacks, hard=%p soft=%p\n", + cpu, hardirq_ctx[cpu], softirq_ctx[cpu]); +} + +void irq_ctx_exit(int cpu) +{ + hardirq_ctx[smp_processor_id()] = NULL; +} + +extern asmlinkage void __do_softirq(void); + +asmlinkage void do_softirq(void) +{ + unsigned long flags; + struct thread_info *curctx; + union irq_ctx *irqctx; + u32 *isp; + + if (in_interrupt()) + return; + + local_irq_save(flags); + + if (local_softirq_pending()) { + curctx = current_thread_info(); + irqctx = softirq_ctx[smp_processor_id()]; + irqctx->tinfo.task = curctx->task; + + /* build the stack frame on the softirq stack */ + isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); + + asm volatile ( + "MOV D0.5,%0\n" + "SWAP A0StP,D0.5\n" + "CALLR D1RtP,___do_softirq\n" + "MOV A0StP,D0.5\n" + : + : "r" (isp) + : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", + "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", + "D0.5" + ); + /* + * Shouldn't happen, we returned above if in_interrupt(): + */ + WARN_ON_ONCE(softirq_count()); + } + + local_irq_restore(flags); +} +#endif + +static struct irq_chip meta_irq_type = { + .name = "META-IRQ", + .irq_startup = startup_meta_irq, + .irq_shutdown = shutdown_meta_irq, +}; + +/** + * tbisig_map() - Map a TBI signal number to a virtual IRQ number. + * @hw: Number of the TBI signal. Must be in range. + * + * Returns: The virtual IRQ number of the TBI signal number IRQ specified by + * @hw. + */ +int tbisig_map(unsigned int hw) +{ + return irq_create_mapping(root_domain, hw); +} + +/** + * metag_tbisig_map() - map a tbi signal to a Linux virtual IRQ number + * @d: root irq domain + * @irq: virtual irq number + * @hw: hardware irq number (TBI signal number) + * + * This sets up a virtual irq for a specified TBI signal number. + */ +static int metag_tbisig_map(struct irq_domain *d, unsigned int irq, + irq_hw_number_t hw) +{ +#ifdef CONFIG_SMP + irq_set_chip_and_handler(irq, &meta_irq_type, handle_percpu_irq); +#else + irq_set_chip_and_handler(irq, &meta_irq_type, handle_simple_irq); +#endif + return 0; +} + +static const struct irq_domain_ops metag_tbisig_domain_ops = { + .map = metag_tbisig_map, +}; + +/* + * void init_IRQ(void) + * + * Parameters: None + * + * Returns: Nothing + * + * This function should be called during kernel startup to initialize + * the IRQ handling routines. + */ +void __init init_IRQ(void) +{ + root_domain = irq_domain_add_linear(NULL, 32, + &metag_tbisig_domain_ops, NULL); + if (unlikely(!root_domain)) + panic("init_IRQ: cannot add root IRQ domain"); + + irq_ctx_init(smp_processor_id()); + + if (machine_desc->init_irq) + machine_desc->init_irq(); +} + +int __init arch_probe_nr_irqs(void) +{ + if (machine_desc->nr_irqs) + nr_irqs = machine_desc->nr_irqs; + return 0; +} + +#ifdef CONFIG_HOTPLUG_CPU +static void route_irq(struct irq_data *data, unsigned int irq, unsigned int cpu) +{ + struct irq_desc *desc = irq_to_desc(irq); + struct irq_chip *chip = irq_data_get_irq_chip(data); + + raw_spin_lock_irq(&desc->lock); + if (chip->irq_set_affinity) + chip->irq_set_affinity(data, cpumask_of(cpu), false); + raw_spin_unlock_irq(&desc->lock); +} + +/* + * The CPU has been marked offline. Migrate IRQs off this CPU. If + * the affinity settings do not allow other CPUs, force them onto any + * available CPU. + */ +void migrate_irqs(void) +{ + unsigned int i, cpu = smp_processor_id(); + struct irq_desc *desc; + + for_each_irq_desc(i, desc) { + struct irq_data *data = irq_desc_get_irq_data(desc); + unsigned int newcpu; + + if (irqd_is_per_cpu(data)) + continue; + + if (!cpumask_test_cpu(cpu, data->affinity)) + continue; + + newcpu = cpumask_any_and(data->affinity, cpu_online_mask); + + if (newcpu >= nr_cpu_ids) { + pr_info_ratelimited("IRQ%u no longer affine to CPU%u\n", + i, cpu); + + cpumask_setall(data->affinity); + newcpu = cpumask_any_and(data->affinity, + cpu_online_mask); + } + + route_irq(data, i, newcpu); + } +} +#endif /* CONFIG_HOTPLUG_CPU */ |
