/*
* Copyright IBM Corp. 2004,2011
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Holger Smolinski <Holger.Smolinski@de.ibm.com>,
* Thomas Spatzier <tspat@de.ibm.com>,
*
* This file contains interrupt related functions.
*/
#include <linux/kernel_stat.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/proc_fs.h>
#include <linux/profile.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/ftrace.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/cpu.h>
#include <asm/irq_regs.h>
#include <asm/cputime.h>
#include <asm/lowcore.h>
#include <asm/irq.h>
#include "entry.h"
struct irq_class {
char *name;
char *desc;
};
static const struct irq_class intrclass_names[] = {
{.name = "EXT" },
{.name = "I/O" },
{.name = "CLK", .desc = "[EXT] Clock Comparator" },
{.name = "EXC", .desc = "[EXT] External Call" },
{.name = "EMS", .desc = "[EXT] Emergency Signal" },
{.name = "TMR", .desc = "[EXT] CPU Timer" },
{.name = "TAL", .desc = "[EXT] Timing Alert" },
{.name = "PFL", .desc = "[EXT] Pseudo Page Fault" },
{.name = "DSD", .desc = "[EXT] DASD Diag" },
{.name = "VRT", .desc = "[EXT] Virtio" },
{.name = "SCP", .desc = "[EXT] Service Call" },
{.name = "IUC", .desc = "[EXT] IUCV" },
{.name = "CPM", .desc = "[EXT] CPU Measurement" },
{.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt" },
{.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt" },
{.name = "DAS", .desc = "[I/O] DASD" },
{.name = "C15", .desc = "[I/O] 3215" },
{.name = "C70", .desc = "[I/O] 3270" },
{.name = "TAP", .desc = "[I/O] Tape" },
{.name = "VMR", .desc = "[I/O] Unit Record Devices" },
{.name = "LCS", .desc = "[I/O] LCS" },
{.name = "CLW", .desc = "[I/O] CLAW" },
{.name = "CTC", .desc = "[I/O] CTC" },
{.name = "APB", .desc = "[I/O] AP Bus" },
{.name = "CSC", .desc = "[I/O] CHSC Subchannel" },
{.name = "NMI", .desc = "[NMI] Machine Check" },
};
/*
* show_interrupts is needed by /proc/interrupts.
*/
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
get_online_cpus();
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(j)
seq_printf(p, "CPU%d ",j);
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
seq_printf(p, "%s: ", intrclass_names[i].name);
#ifndef CONFIG_SMP
seq_printf(p, "%10u ", kstat_irqs(i));
#else
for_each_online_cpu(j)
seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
#endif
if (intrclass_names[i].desc)
seq_printf(p, " %s", intrclass_names[i].desc);
seq_putc(p, '\n');
}
put_online_cpus();
return 0;
}
/*
* Switch to the asynchronous interrupt stack for softirq execution.
*/
asmlinkage void do_softirq(void)
{
unsigned long flags, old, new;
if (in_interrupt())
return;
local_irq_save(flags);
if (local_softirq_pending()) {
/* Get current stack pointer. */
asm volatile("la %0,0(15)" : "=a" (old));
/* Check against async. stack address range. */
new = S390_lowcore.async_stack;
if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) {
/* Need to switch to the async. stack. */
new -= STACK_FRAME_OVERHEAD;
((struct stack_frame *) new)->back_chain = old;
asm volatile(" la 15,0(%0)\n"
" basr 14,%2\n"
" la 15,0(%1)\n"
: : "a" (new), "a" (old),
"a" (__do_softirq)
: "0", "1", "2", "3", "4", "5", "14",
"cc", "memory" );
} else
/* We are already on the async stack. */
__do_softirq();
}
local_irq_restore(flags);
}
#ifdef CONFIG_PROC_FS
void init_irq_proc(void)
{
struct proc_dir_entry *root_irq_dir;
root_irq_dir = proc_mkdir("irq", NULL);
create_prof_cpu_mask(root_irq_dir);
}
#endif
/*
* ext_int_hash[index] is the list head for all external interrupts that hash
* to this index.
*/
static struct list_head ext_int_hash[256];
struct ext_int_info {
ext_int_handler_t handler;
u16 code;
struct list_head entry;
struct rcu_head rcu;
};
/* ext_int_hash_lock protects the handler lists for external interrupts */
DEFINE_SPINLOCK(ext_int_hash_lock);
static void __init init_external_interrupts(void)
{
int idx;
for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
INIT_LIST_HEAD(&ext_int_hash[idx]);
}
static inline int ext_hash(u16 code)
{
return (code + (code >> 9)) & 0xff;
}
int register_external_interrupt(u16 code, ext_int_handler_t handler)
{
struct ext_int_info *p;
unsigned long flags;
int index;
p = kmalloc(sizeof(*p), GFP_ATOMIC);
if (!p)
return -ENOMEM;
p->code = code;
p->handler = handler;
index = ext_hash(code);
spin_lock_irqsave(&ext_int_hash_lock, flags);
list_add_rcu(&p->entry, &ext_int_hash[index]);
spin_unlock_irqrestore(&ext_int_hash_lock, flags);
return 0;
}
EXPORT_SYMBOL(register_external_interrupt);
int unregister_external_interrupt(u16 code, ext_int_handler_t handler)
{
struct ext_int_info *p;
unsigned long flags;
int index = ext_hash(code);
spin_lock_irqsave(&ext_int_hash_lock, flags);
list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
if (p->code == code && p->handler == handler) {
list_del_rcu(&p->entry);
kfree_rcu(p, rcu);
}
spin_unlock_irqrestore(&ext_int_hash_lock, flags);
return 0;
}
EXPORT_SYMBOL(unregister_external_interrupt);
void __irq_entry do_extint(struct pt_regs *regs, struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct pt_regs *old_regs;
struct ext_int_info *p;
int index;
old_regs = set_irq_regs(regs);
irq_enter();
if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
/* Serve timer interrupts first. */
clock_comparator_work();
kstat_cpu(smp_processor_id()).irqs[EXTERNAL_INTERRUPT]++;
if (ext_code.code != 0x1004)
__get_cpu_var(s390_idle).nohz_delay = 1;
index = ext_hash(ext_code.code);
rcu_read_lock();
list_for_each_entry_rcu(p, &ext_int_hash[index], entry)
if (likely(p->code == ext_code.code))
p->handler(ext_code, param32, param64);
rcu_read_unlock();
irq_exit();
set_irq_regs(old_regs);
}
void __init init_IRQ(void)
{
init_external_interrupts();
}
static DEFINE_SPINLOCK(sc_irq_lock);
static int sc_irq_refcount;
void service_subclass_irq_register(void)
{
spin_lock(&sc_irq_lock);
if (!sc_irq_refcount)
ctl_set_bit(0, 9);
sc_irq_refcount++;
spin_unlock(&sc_irq_lock);
}
EXPORT_SYMBOL(service_subclass_irq_register);
void service_subclass_irq_unregister(void)
{
spin_lock(&sc_irq_lock);
sc_irq_refcount--;
if (!sc_irq_refcount)
ctl_clear_bit(0, 9);
spin_unlock(&sc_irq_lock);
}
EXPORT_SYMBOL(service_subclass_irq_unregister);
