/*
* 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 <asm/hw_irq.h>
#include "entry.h"
DEFINE_PER_CPU_SHARED_ALIGNED(struct irq_stat, irq_stat);
EXPORT_PER_CPU_SYMBOL_GPL(irq_stat);
struct irq_class {
char *name;
char *desc;
};
/*
* The list of "main" irq classes on s390. This is the list of interrupts
* that appear both in /proc/stat ("intr" line) and /proc/interrupts.
* Historically only external and I/O interrupts have been part of /proc/stat.
* We can't add the split external and I/O sub classes since the first field
* in the "intr" line in /proc/stat is supposed to be the sum of all other
* fields.
* Since the external and I/O interrupt fields are already sums we would end
* up with having a sum which accounts each interrupt twice.
*/
static const struct irq_class irqclass_main_desc[NR_IRQS_BASE] = {
[EXT_INTERRUPT] = {.name = "EXT"},
[IO_INTERRUPT] = {.name = "I/O"},
[THIN_INTERRUPT] = {.name = "AIO"},
};
/*
* The list of split external and I/O interrupts that appear only in
* /proc/interrupts.
* In addition this list contains non external / I/O events like NMIs.
*/
static const struct irq_class irqclass_sub_desc[NR_ARCH_IRQS] = {
[IRQEXT_CLK] = {.name = "CLK", .desc = "[EXT] Clock Comparator"},
[IRQEXT_EXC] = {.name = "EXC", .desc = "[EXT] External Call"},
[IRQEXT_EMS] = {.name = "EMS", .desc = "[EXT] Emergency Signal"},
[IRQEXT_TMR] = {.name = "TMR", .desc = "[EXT] CPU Timer"},
[IRQEXT_TLA] = {.name = "TAL", .desc = "[EXT] Timing Alert"},
[IRQEXT_PFL] = {.name = "PFL", .desc = "[EXT] Pseudo Page Fault"},
[IRQEXT_DSD] = {.name = "DSD", .desc = "[EXT] DASD Diag"},
[IRQEXT_VRT] = {.name = "VRT", .desc = "[EXT] Virtio"},
[IRQEXT_SCP] = {.name = "SCP", .desc = "[EXT] Service Call"},
[IRQEXT_IUC] = {.name = "IUC", .desc = "[EXT] IUCV"},
[IRQEXT_CMS] = {.name = "CMS", .desc = "[EXT] CPU-Measurement: Sampling"},
[IRQEXT_CMC] = {.name = "CMC", .desc = "[EXT] CPU-Measurement: Counter"},
[IRQEXT_CMR] = {.name = "CMR", .desc = "[EXT] CPU-Measurement: RI"},
[IRQIO_CIO] = {.name = "CIO", .desc = "[I/O] Common I/O Layer Interrupt"},
[IRQIO_QAI] = {.name = "QAI", .desc = "[I/O] QDIO Adapter Interrupt"},
[IRQIO_DAS] = {.name = "DAS", .desc = "[I/O] DASD"},
[IRQIO_C15] = {.name = "C15", .desc = "[I/O] 3215"},
[IRQIO_C70] = {.name = "C70", .desc = "[I/O] 3270"},
[IRQIO_TAP] = {.name = "TAP", .desc = "[I/O] Tape"},
[IRQIO_VMR] = {.name = "VMR", .desc = "[I/O] Unit Record Devices"},
[IRQIO_LCS] = {.name = "LCS", .desc = "[I/O] LCS"},
[IRQIO_CLW] = {.name = "CLW", .desc = "[I/O] CLAW"},
[IRQIO_CTC] = {.name = "CTC", .desc = "[I/O] CTC"},
[IRQIO_APB] = {.name = "APB", .desc = "[I/O] AP Bus"},
[IRQIO_ADM] = {.name = "ADM", .desc = "[I/O] EADM Subchannel"},
[IRQIO_CSC] = {.name = "CSC", .desc = "[I/O] CHSC Subchannel"},
[IRQIO_PCI] = {.name = "PCI", .desc = "[I/O] PCI Interrupt" },
[IRQIO_MSI] = {.name = "MSI", .desc = "[I/O] MSI Interrupt" },
[IRQIO_VIR] = {.name = "VIR", .desc = "[I/O] Virtual I/O Devices"},
[NMI_NMI] = {.name = "NMI", .desc = "[NMI] Machine Check"},
[CPU_RST] = {.name = "RST", .desc = "[CPU] CPU Restart"},
};
void __init init_IRQ(void)
{
irq_reserve_irqs(0, THIN_INTERRUPT);
init_cio_interrupts();
init_airq_interrupts();
init_ext_interrupts();
}
void do_IRQ(struct pt_regs *regs, int irq)
{
struct pt_regs *old_regs;
old_regs = set_irq_regs(regs);
irq_enter();
if (S390_lowcore.int_clock >= S390_lowcore.clock_comparator)
/* Serve timer interrupts first. */
clock_comparator_work();
generic_handle_irq(irq);
irq_exit();
set_irq_regs(old_regs);
}
/*
* show_interrupts is needed by /proc/interrupts.
*/
int show_interrupts(struct seq_file *p, void *v)
{
int irq = *(loff_t *) v;
int cpu;
get_online_cpus();
if (irq == 0) {
seq_puts(p, " ");
for_each_online_cpu(cpu)
seq_printf(p, "CPU%d ", cpu);
seq_putc(p, '\n');
goto out;
}
if (irq < NR_IRQS) {
if (irq >= NR_IRQS_BASE)
goto out;
seq_printf(p, "%s: ", irqclass_main_desc[irq].name);
for_each_online_cpu(cpu)
seq_printf(p, "%10u ", kstat_irqs_cpu(irq, cpu));
seq_putc(p, '\n');
goto out;
}
for (irq = 0; irq < NR_ARCH_IRQS; irq++) {
seq_printf(p, "%s: ", irqclass_sub_desc[irq].name);
for_each_online_cpu(cpu)
seq_printf(p, "%10u ",
per_cpu(irq_stat, cpu).irqs[irq]);
if (irqclass_sub_desc[irq].desc)
seq_printf(p, " %s", irqclass_sub_desc[irq].desc);
seq_putc(p, '\n');
}
out:
put_online_cpus();
return 0;
}
int arch_show_interrupts(struct seq_file *p, int prec)
{
return 0;
}
/*
* Switch to the asynchronous interrupt stack for softirq execution.
*/
void do_softirq_own_stack(void)
{
unsigned long old, new;
/* 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();
}
}
/*
* ext_int_hash[index] is the list head for all external interrupts that hash
* to this index.
*/
static struct hlist_head ext_int_hash[32] ____cacheline_aligned;
struct ext_int_info {
ext_int_handler_t handler;
struct hlist_node entry;
struct rcu_head rcu;
u16 code;
};
/* ext_int_hash_lock protects the handler lists for external interrupts */
static DEFINE_SPINLOCK(ext_int_hash_lock);
static inline int ext_hash(u16 code)
{
BUILD_BUG_ON(!is_power_of_2(ARRAY_SIZE(ext_int_hash)));
return (code + (code >> 9)) & (ARRAY_SIZE(ext_int_hash) - 1);
}
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);
hlist_add_head_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);
hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
if (p->code == code && p->handler == handler) {
hlist_del_rcu(&p->entry);
kfree_rcu(p, rcu);
}
}
spin_unlock_irqrestore(&ext_int_hash_lock, flags);
return 0;
}
EXPORT_SYMBOL(unregister_external_interrupt);
static irqreturn_t do_ext_interrupt(int irq, void *dummy)
{
struct pt_regs *regs = get_irq_regs();
struct ext_code ext_code;
struct ext_int_info *p;
int index;
ext_code = *(struct ext_code *) ®s->int_code;
if (ext_code.code != 0x1004)
__get_cpu_var(s390_idle).nohz_delay = 1;
index = ext_hash(ext_code.code);
rcu_read_lock();
hlist_for_each_entry_rcu(p, &ext_int_hash[index], entry) {
if (unlikely(p->code != ext_code.code))
continue;
p->handler(ext_code, regs->int_parm, regs->int_parm_long);
}
rcu_read_unlock();
return IRQ_HANDLED;
}
static struct irqaction external_interrupt = {
.name = "EXT",
.handler = do_ext_interrupt,
};
void __init init_ext_interrupts(void)
{
int idx;
for (idx = 0; idx < ARRAY_SIZE(ext_int_hash); idx++)
INIT_HLIST_HEAD(&ext_int_hash[idx]);
irq_set_chip_and_handler(EXT_INTERRUPT,
&dummy_irq_chip, handle_percpu_irq);
setup_irq(EXT_INTERRUPT, &external_interrupt);
}
static DEFINE_SPINLOCK(irq_subclass_lock);
static unsigned char irq_subclass_refcount[64];
void irq_subclass_register(enum irq_subclass subclass)
{
spin_lock(&irq_subclass_lock);
if (!irq_subclass_refcount[subclass])
ctl_set_bit(0, subclass);
irq_subclass_refcount[subclass]++;
spin_unlock(&irq_subclass_lock);
}
EXPORT_SYMBOL(irq_subclass_register);
void irq_subclass_unregister(enum irq_subclass subclass)
{
spin_lock(&irq_subclass_lock);
irq_subclass_refcount[subclass]--;
if (!irq_subclass_refcount[subclass])
ctl_clear_bit(0, subclass);
spin_unlock(&irq_subclass_lock);
}
EXPORT_SYMBOL(irq_subclass_unregister);
