// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Code to handle x86 style IRQs plus some generic interrupt stuff.
*
* Copyright (C) 1992 Linus Torvalds
* Copyright (C) 1994, 1995, 1996, 1997, 1998 Ralf Baechle
* Copyright (C) 1999 SuSE GmbH (Philipp Rumpf, [email protected])
* Copyright (C) 1999-2000 Grant Grundler
* Copyright (c) 2005 Matthew Wilcox
*/
#include <linux/bitops.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/seq_file.h>
#include <linux/types.h>
#include <linux/sched/task_stack.h>
#include <asm/io.h>
#include <asm/softirq_stack.h>
#include <asm/smp.h>
#include <asm/ldcw.h>
#undef PARISC_IRQ_CR16_COUNTS
#define EIEM_MASK(irq) (1UL<<(CPU_IRQ_MAX - irq))
/* Bits in EIEM correlate with cpu_irq_action[].
** Numbered *Big Endian*! (ie bit 0 is MSB)
*/
static volatile unsigned long cpu_eiem = 0;
/*
** local ACK bitmap ... habitually set to 1, but reset to zero
** between ->ack() and ->end() of the interrupt to prevent
** re-interruption of a processing interrupt.
*/
static DEFINE_PER_CPU(unsigned long, local_ack_eiem) = ~0UL;
static void cpu_mask_irq(struct irq_data *d)
{
unsigned long eirr_bit = EIEM_MASK(d->irq);
cpu_eiem &= ~eirr_bit;
/* Do nothing on the other CPUs. If they get this interrupt,
* The & cpu_eiem in the do_cpu_irq_mask() ensures they won't
* handle it, and the set_eiem() at the bottom will ensure it
* then gets disabled */
}
static void __cpu_unmask_irq(unsigned int irq)
{
unsigned long eirr_bit = EIEM_MASK(irq);
cpu_eiem |= eirr_bit;
/* This is just a simple NOP IPI. But what it does is cause
* all the other CPUs to do a set_eiem(cpu_eiem) at the end
* of the interrupt handler */
smp_send_all_nop();
}
static void cpu_unmask_irq(struct irq_data *d)
{
__cpu_unmask_irq(d->irq);
}
void cpu_ack_irq(struct irq_data *d)
{
unsigned long mask = EIEM_MASK(d->irq);
int cpu = smp_processor_id();
/* Clear in EIEM so we can no longer process */
per_cpu(local_ack_eiem, cpu) &= ~mask;
/* disable the interrupt */
set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
/* and now ack it */
mtctl(mask, 23);
}
void cpu_eoi_irq(struct irq_data *d)
{
unsigned long mask = EIEM_MASK(d->irq);
int cpu = smp_processor_id();
/* set it in the eiems---it's no longer in process */
per_cpu(local_ack_eiem, cpu) |= mask;
/* enable the interrupt */
set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
}
#ifdef CONFIG_SMP
int cpu_check_affinity(struct irq_data *d, const struct cpumask *dest)
{
int cpu_dest;
/* timer and ipi have to always be received on all CPUs */
if (irqd_is_per_cpu(d))
return -EINVAL;
cpu_dest = cpumask_first_and(dest, cpu_online_mask);
if (cpu_dest >= nr_cpu_ids)
cpu_dest = cpumask_first(cpu_online_mask);
return cpu_dest;
}
#endif
static struct irq_chip cpu_interrupt_type = {
.name = "CPU",
.irq_mask = cpu_mask_irq,
.irq_unmask = cpu_unmask_irq,
.irq_ack = cpu_ack_irq,
.irq_eoi = cpu_eoi_irq,
/* XXX: Needs to be written. We managed without it so far, but
* we really ought to write it.
*/
.irq_retrigger = NULL,
};
DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
#define irq_stats(x) (&per_cpu(irq_stat, x))
/*
* /proc/interrupts printing for arch specific interrupts
*/
int arch_show_interrupts(struct seq_file *p, int prec)
{
int j;
#ifdef CONFIG_DEBUG_STACKOVERFLOW
seq_printf(p, "%*s: ", prec, "STK");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->kernel_stack_usage);
seq_puts(p, " Kernel stack usage\n");
# ifdef CONFIG_IRQSTACKS
seq_printf(p, "%*s: ", prec, "IST");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_stack_usage);
seq_puts(p, " Interrupt stack usage\n");
# endif
#endif
#ifdef CONFIG_SMP
if (num_online_cpus() > 1) {
seq_printf(p, "%*s: ", prec, "RES");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_resched_count);
seq_puts(p, " Rescheduling interrupts\n");
seq_printf(p, "%*s: ", prec, "CAL");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_call_count);
seq_puts(p, " Function call interrupts\n");
}
#endif
seq_printf(p, "%*s: ", prec, "UAH");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_unaligned_count);
seq_puts(p, " Unaligned access handler traps\n");
seq_printf(p, "%*s: ", prec, "FPA");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_fpassist_count);
seq_puts(p, " Floating point assist traps\n");
seq_printf(p, "%*s: ", prec, "TLB");
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_stats(j)->irq_tlb_count);
seq_puts(p, " TLB shootdowns\n");
return 0;
}
int show_interrupts(struct seq_file *p, void *v)
{
int i = *(loff_t *) v, j;
unsigned long flags;
if (i == 0) {
seq_puts(p, " ");
for_each_online_cpu(j)
seq_printf(p, " CPU%d", j);
#ifdef PARISC_IRQ_CR16_COUNTS
seq_printf(p, " [min/avg/max] (CPU cycle counts)");
#endif
seq_putc(p, '\n');
}
if (i < NR_IRQS) {
struct irq_desc *desc = irq_to_desc(i);
struct irqaction *action;
raw_spin_lock_irqsave(&desc->lock, flags);
action = desc->action;
if (!action)
goto skip;
seq_printf(p, "%3d: ", i);
for_each_online_cpu(j)
seq_printf(p, "%10u ", irq_desc_kstat_cpu(desc, j));
seq_printf(p, " %14s", irq_desc_get_chip(desc)->name);
#ifndef PARISC_IRQ_CR16_COUNTS
seq_printf(p, " %s", action->name);
while ((action = action->next))
seq_printf(p, ", %s", action->name);
#else
for ( ;action; action = action->next) {
unsigned int k, avg, min, max;
min = max = action->cr16_hist[0];
for (avg = k = 0; k < PARISC_CR16_HIST_SIZE; k++) {
int hist = action->cr16_hist[k];
if (hist) {
avg += hist;
} else
break;
if (hist > max) max = hist;
if (hist < min) min = hist;
}
avg /= k;
seq_printf(p, " %s[%d/%d/%d]", action->name,
min,avg,max);
}
#endif
seq_putc(p, '\n');
skip:
raw_spin_unlock_irqrestore(&desc->lock, flags);
}
if (i == NR_IRQS)
arch_show_interrupts(p, 3);
return 0;
}
/*
** The following form a "set": Virtual IRQ, Transaction Address, Trans Data.
** Respectively, these map to IRQ region+EIRR, Processor HPA, EIRR bit.
**
** To use txn_XXX() interfaces, get a Virtual IRQ first.
** Then use that to get the Transaction address and data.
*/
int cpu_claim_irq(unsigned int irq, struct irq_chip *type, void *data)
{
if (irq_has_action(irq))
return -EBUSY;
if (irq_get_chip(irq) != &cpu_interrupt_type)
return -EBUSY;
/* for iosapic interrupts */
if (type) {
irq_set_chip_and_handler(irq, type, handle_percpu_irq);
irq_set_chip_data(irq, data);
__cpu_unmask_irq(irq);
}
return 0;
}
int txn_claim_irq(int irq)
{
return cpu_claim_irq(irq, NULL, NULL) ? -1 : irq;
}
/*
* The bits_wide parameter accommodates the limitations of the HW/SW which
* use these bits:
* Legacy PA I/O (GSC/NIO): 5 bits (architected EIM register)
* V-class (EPIC): 6 bits
* N/L/A-class (iosapic): 8 bits
* PCI 2.2 MSI: 16 bits
* Some PCI devices: 32 bits (Symbios SCSI/ATM/HyperFabric)
*
* On the service provider side:
* o PA 1.1 (and PA2.0 narrow mode) 5-bits (width of EIR register)
* o PA 2.0 wide mode 6-bits (per processor)
* o IA64 8-bits (0-256 total)
*
* So a Legacy PA I/O device on a PA 2.0 box can't use all the bits supported
* by the processor...and the N/L-class I/O subsystem supports more bits than
* PA2.0 has. The first case is the problem.
*/
int txn_alloc_irq(unsigned int bits_wide)
{
int irq;
/* never return irq 0 cause that's the interval timer */
for (irq = CPU_IRQ_BASE + 1; irq <= CPU_IRQ_MAX; irq++) {
if (cpu_claim_irq(irq, NULL, NULL) < 0)
continue;
if ((irq - CPU_IRQ_BASE) >= (1 << bits_wide))
continue;
return irq;
}
/* unlikely, but be prepared */
return -1;
}
unsigned long txn_affinity_addr(unsigned int irq, int cpu)
{
#ifdef CONFIG_SMP
struct irq_data *d = irq_get_irq_data(irq);
irq_data_update_affinity(d, cpumask_of(cpu));
#endif
return per_cpu(cpu_data, cpu).txn_addr;
}
unsigned long txn_alloc_addr(unsigned int virt_irq)
{
static int next_cpu = -1;
next_cpu++; /* assign to "next" CPU we want this bugger on */
/* validate entry */
while ((next_cpu < nr_cpu_ids) &&
(!per_cpu(cpu_data, next_cpu).txn_addr ||
!cpu_online(next_cpu)))
next_cpu++;
if (next_cpu >= nr_cpu_ids)
next_cpu = 0; /* nothing else, assign monarch */
return txn_affinity_addr(virt_irq, next_cpu);
}
unsigned int txn_alloc_data(unsigned int virt_irq)
{
return virt_irq - CPU_IRQ_BASE;
}
static inline int eirr_to_irq(unsigned long eirr)
{
int bit = fls_long(eirr);
return (BITS_PER_LONG - bit) + TIMER_IRQ;
}
#ifdef CONFIG_IRQSTACKS
/*
* IRQ STACK - used for irq handler
*/
#ifdef CONFIG_64BIT
#define IRQ_STACK_SIZE (4096 << 4) /* 64k irq stack size */
#else
#define IRQ_STACK_SIZE (4096 << 3) /* 32k irq stack size */
#endif
union irq_stack_union {
unsigned long stack[IRQ_STACK_SIZE/sizeof(unsigned long)];
volatile unsigned int slock[4];
volatile unsigned int lock[1];
};
static DEFINE_PER_CPU(union irq_stack_union, irq_stack_union) = {
.slock = { 1,1,1,1 },
};
#endif
int sysctl_panic_on_stackoverflow = 1;
static inline void stack_overflow_check(struct pt_regs *regs)
{
#ifdef CONFIG_DEBUG_STACKOVERFLOW
#define STACK_MARGIN (256*6)
unsigned long stack_start = (unsigned long) task_stack_page(current);
unsigned long sp = regs->gr[30];
unsigned long stack_usage;
unsigned int *last_usage;
int cpu = smp_processor_id();
/* if sr7 != 0, we interrupted a userspace process which we do not want
* to check for stack overflow. We will only check the kernel stack. */
if (regs->sr[7])
return;
/* exit if already in panic */
if (sysctl_panic_on_stackoverflow < 0)
return;
/* calculate kernel stack usage */
stack_usage = sp - stack_start;
#ifdef CONFIG_IRQSTACKS
if (likely(stack_usage <= THREAD_SIZE))
goto check_kernel_stack; /* found kernel stack */
/* check irq stack usage */
stack_start = (unsigned long) &per_cpu(irq_stack_union, cpu).stack;
stack_usage = sp - stack_start;
last_usage = &per_cpu(irq_stat.irq_stack_usage, cpu);
if (unlikely(stack_usage > *last_usage))
*last_usage = stack_usage;
if (likely(stack_usage < (IRQ_STACK_SIZE - STACK_MARGIN)))
return;
pr_emerg("stackcheck: %s will most likely overflow irq stack "
"(sp:%lx, stk bottom-top:%lx-%lx)\n",
current->comm, sp, stack_start, stack_start + IRQ_STACK_SIZE);
goto panic_check;
check_kernel_stack:
#endif
/* check kernel stack usage */
last_usage = &per_cpu(irq_stat.kernel_stack_usage, cpu);
if (unlikely(stack_usage > *last_usage))
*last_usage = stack_usage;
if (likely(stack_usage < (THREAD_SIZE - STACK_MARGIN)))
return;
pr_emerg("stackcheck: %s will most likely overflow kernel stack "
"(sp:%lx, stk bottom-top:%lx-%lx)\n",
current->comm, sp, stack_start, stack_start + THREAD_SIZE);
#ifdef CONFIG_IRQSTACKS
panic_check:
#endif
if (sysctl_panic_on_stackoverflow) {
sysctl_panic_on_stackoverflow = -1; /* disable further checks */
panic("low stack detected by irq handler - check messages\n");
}
#endif
}
#ifdef CONFIG_IRQSTACKS
/* in entry.S: */
void call_on_stack(unsigned long p1, void *func, unsigned long new_stack);
static void execute_on_irq_stack(void *func, unsigned long param1)
{
union irq_stack_union *union_ptr;
unsigned long irq_stack;
volatile unsigned int *irq_stack_in_use;
union_ptr = &per_cpu(irq_stack_union, smp_processor_id());
irq_stack = (unsigned long) &union_ptr->stack;
irq_stack = ALIGN(irq_stack + sizeof(irq_stack_union.slock),
FRAME_ALIGN); /* align for stack frame usage */
/* We may be called recursive. If we are already using the irq stack,
* just continue to use it. Use spinlocks to serialize
* the irq stack usage.
*/
irq_stack_in_use = (volatile unsigned int *)__ldcw_align(union_ptr);
if (!__ldcw(irq_stack_in_use)) {
void (*direct_call)(unsigned long p1) = func;
/* We are using the IRQ stack already.
* Do direct call on current stack. */
direct_call(param1);
return;
}
/* This is where we switch to the IRQ stack. */
call_on_stack(param1, func, irq_stack);
/* free up irq stack usage. */
*irq_stack_in_use = 1;
}
#ifdef CONFIG_SOFTIRQ_ON_OWN_STACK
void do_softirq_own_stack(void)
{
execute_on_irq_stack(__do_softirq, 0);
}
#endif
#endif /* CONFIG_IRQSTACKS */
/* ONLY called from entry.S:intr_extint() */
asmlinkage void do_cpu_irq_mask(struct pt_regs *regs)
{
struct pt_regs *old_regs;
unsigned long eirr_val;
int irq, cpu = smp_processor_id();
struct irq_data *irq_data;
#ifdef CONFIG_SMP
cpumask_t dest;
#endif
old_regs = set_irq_regs(regs);
local_irq_disable();
irq_enter_rcu();
eirr_val = mfctl(23) & cpu_eiem & per_cpu(local_ack_eiem, cpu);
if (!eirr_val)
goto set_out;
irq = eirr_to_irq(eirr_val);
irq_data = irq_get_irq_data(irq);
/* Filter out spurious interrupts, mostly from serial port at bootup */
if (unlikely(!irq_desc_has_action(irq_data_to_desc(irq_data))))
goto set_out;
#ifdef CONFIG_SMP
cpumask_copy(&dest, irq_data_get_affinity_mask(irq_data));
if (irqd_is_per_cpu(irq_data) &&
!cpumask_test_cpu(smp_processor_id(), &dest)) {
int cpu = cpumask_first(&dest);
printk(KERN_DEBUG "redirecting irq %d from CPU %d to %d\n",
irq, smp_processor_id(), cpu);
gsc_writel(irq + CPU_IRQ_BASE,
per_cpu(cpu_data, cpu).hpa);
goto set_out;
}
#endif
stack_overflow_check(regs);
#ifdef CONFIG_IRQSTACKS
execute_on_irq_stack(&generic_handle_irq, irq);
#else
generic_handle_irq(irq);
#endif /* CONFIG_IRQSTACKS */
out:
irq_exit_rcu();
set_irq_regs(old_regs);
return;
set_out:
set_eiem(cpu_eiem & per_cpu(local_ack_eiem, cpu));
goto out;
}
static void claim_cpu_irqs(void)
{
unsigned long flags = IRQF_TIMER | IRQF_PERCPU | IRQF_IRQPOLL;
int i;
for (i = CPU_IRQ_BASE; i <= CPU_IRQ_MAX; i++) {
irq_set_chip_and_handler(i, &cpu_interrupt_type,
handle_percpu_irq);
}
irq_set_handler(TIMER_IRQ, handle_percpu_irq);
if (request_irq(TIMER_IRQ, timer_interrupt, flags, "timer", NULL))
pr_err("Failed to register timer interrupt\n");
#ifdef CONFIG_SMP
irq_set_handler(IPI_IRQ, handle_percpu_irq);
if (request_irq(IPI_IRQ, ipi_interrupt, IRQF_PERCPU, "IPI", NULL))
pr_err("Failed to register IPI interrupt\n");
#endif
}
void init_IRQ(void)
{
local_irq_disable(); /* PARANOID - should already be disabled */
mtctl(~0UL, 23); /* EIRR : clear all pending external intr */
#ifdef CONFIG_SMP
if (!cpu_eiem) {
claim_cpu_irqs();
cpu_eiem = EIEM_MASK(IPI_IRQ) | EIEM_MASK(TIMER_IRQ);
}
#else
claim_cpu_irqs();
cpu_eiem = EIEM_MASK(TIMER_IRQ);
#endif
set_eiem(cpu_eiem); /* EIEM : enable all external intr */
}
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