linux/arch/powerpc/kernel/irq.c
Nicholas Piggin ff058a8ada powerpc/64: warn if local irqs are enabled in NMI or hardirq context
This can help catch bugs such as the one fixed by the previous change
to prevent _exception() from enabling irqs.

ppc32 could have a similar warning but it has no good config option to
debug this stuff (the test may be overkill to add for production
kernels).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211004145642.1331214-4-npiggin@gmail.com
2021-10-07 19:54:55 +11:00

880 lines
23 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Derived from arch/i386/kernel/irq.c
* Copyright (C) 1992 Linus Torvalds
* Adapted from arch/i386 by Gary Thomas
* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
* Updated and modified by Cort Dougan <cort@fsmlabs.com>
* Copyright (C) 1996-2001 Cort Dougan
* Adapted for Power Macintosh by Paul Mackerras
* Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
*
* This file contains the code used by various IRQ handling routines:
* asking for different IRQ's should be done through these routines
* instead of just grabbing them. Thus setups with different IRQ numbers
* shouldn't result in any weird surprises, and installing new handlers
* should be easier.
*
* The MPC8xx has an interrupt mask in the SIU. If a bit is set, the
* interrupt is _enabled_. As expected, IRQ0 is bit 0 in the 32-bit
* mask register (of which only 16 are defined), hence the weird shifting
* and complement of the cached_irq_mask. I want to be able to stuff
* this right into the SIU SMASK register.
* Many of the prep/chrp functions are conditional compiled on CONFIG_PPC_8xx
* to reduce code space and undefined function references.
*/
#undef DEBUG
#include <linux/export.h>
#include <linux/threads.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ptrace.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/seq_file.h>
#include <linux/cpumask.h>
#include <linux/profile.h>
#include <linux/bitops.h>
#include <linux/list.h>
#include <linux/radix-tree.h>
#include <linux/mutex.h>
#include <linux/pci.h>
#include <linux/debugfs.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/vmalloc.h>
#include <linux/pgtable.h>
#include <linux/uaccess.h>
#include <asm/interrupt.h>
#include <asm/io.h>
#include <asm/irq.h>
#include <asm/cache.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/machdep.h>
#include <asm/udbg.h>
#include <asm/smp.h>
#include <asm/livepatch.h>
#include <asm/asm-prototypes.h>
#include <asm/hw_irq.h>
#include <asm/softirq_stack.h>
#ifdef CONFIG_PPC64
#include <asm/paca.h>
#include <asm/firmware.h>
#include <asm/lv1call.h>
#include <asm/dbell.h>
#endif
#define CREATE_TRACE_POINTS
#include <asm/trace.h>
#include <asm/cpu_has_feature.h>
DEFINE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
EXPORT_PER_CPU_SYMBOL(irq_stat);
#ifdef CONFIG_PPC32
atomic_t ppc_n_lost_interrupts;
#ifdef CONFIG_TAU_INT
extern int tau_initialized;
u32 tau_interrupts(unsigned long cpu);
#endif
#endif /* CONFIG_PPC32 */
#ifdef CONFIG_PPC64
int distribute_irqs = 1;
static inline notrace unsigned long get_irq_happened(void)
{
unsigned long happened;
__asm__ __volatile__("lbz %0,%1(13)"
: "=r" (happened) : "i" (offsetof(struct paca_struct, irq_happened)));
return happened;
}
void replay_soft_interrupts(void)
{
struct pt_regs regs;
/*
* Be careful here, calling these interrupt handlers can cause
* softirqs to be raised, which they may run when calling irq_exit,
* which will cause local_irq_enable() to be run, which can then
* recurse into this function. Don't keep any state across
* interrupt handler calls which may change underneath us.
*
* We use local_paca rather than get_paca() to avoid all the
* debug_smp_processor_id() business in this low level function.
*/
ppc_save_regs(&regs);
regs.softe = IRQS_ENABLED;
regs.msr |= MSR_EE;
again:
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(mfmsr() & MSR_EE);
/*
* Force the delivery of pending soft-disabled interrupts on PS3.
* Any HV call will have this side effect.
*/
if (firmware_has_feature(FW_FEATURE_PS3_LV1)) {
u64 tmp, tmp2;
lv1_get_version_info(&tmp, &tmp2);
}
/*
* Check if an hypervisor Maintenance interrupt happened.
* This is a higher priority interrupt than the others, so
* replay it first.
*/
if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_HMI)) {
local_paca->irq_happened &= ~PACA_IRQ_HMI;
regs.trap = INTERRUPT_HMI;
handle_hmi_exception(&regs);
if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS))
hard_irq_disable();
}
if (local_paca->irq_happened & PACA_IRQ_DEC) {
local_paca->irq_happened &= ~PACA_IRQ_DEC;
regs.trap = INTERRUPT_DECREMENTER;
timer_interrupt(&regs);
if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS))
hard_irq_disable();
}
if (local_paca->irq_happened & PACA_IRQ_EE) {
local_paca->irq_happened &= ~PACA_IRQ_EE;
regs.trap = INTERRUPT_EXTERNAL;
do_IRQ(&regs);
if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS))
hard_irq_disable();
}
if (IS_ENABLED(CONFIG_PPC_DOORBELL) && (local_paca->irq_happened & PACA_IRQ_DBELL)) {
local_paca->irq_happened &= ~PACA_IRQ_DBELL;
regs.trap = INTERRUPT_DOORBELL;
doorbell_exception(&regs);
if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS))
hard_irq_disable();
}
/* Book3E does not support soft-masking PMI interrupts */
if (IS_ENABLED(CONFIG_PPC_BOOK3S) && (local_paca->irq_happened & PACA_IRQ_PMI)) {
local_paca->irq_happened &= ~PACA_IRQ_PMI;
regs.trap = INTERRUPT_PERFMON;
performance_monitor_exception(&regs);
if (!(local_paca->irq_happened & PACA_IRQ_HARD_DIS))
hard_irq_disable();
}
if (local_paca->irq_happened & ~PACA_IRQ_HARD_DIS) {
/*
* We are responding to the next interrupt, so interrupt-off
* latencies should be reset here.
*/
trace_hardirqs_on();
trace_hardirqs_off();
goto again;
}
}
#if defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_PPC_KUAP)
static inline void replay_soft_interrupts_irqrestore(void)
{
unsigned long kuap_state = get_kuap();
/*
* Check if anything calls local_irq_enable/restore() when KUAP is
* disabled (user access enabled). We handle that case here by saving
* and re-locking AMR but we shouldn't get here in the first place,
* hence the warning.
*/
kuap_assert_locked();
if (kuap_state != AMR_KUAP_BLOCKED)
set_kuap(AMR_KUAP_BLOCKED);
replay_soft_interrupts();
if (kuap_state != AMR_KUAP_BLOCKED)
set_kuap(kuap_state);
}
#else
#define replay_soft_interrupts_irqrestore() replay_soft_interrupts()
#endif
#ifdef CONFIG_CC_HAS_ASM_GOTO
notrace void arch_local_irq_restore(unsigned long mask)
{
unsigned char irq_happened;
/* Write the new soft-enabled value if it is a disable */
if (mask) {
irq_soft_mask_set(mask);
return;
}
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(in_nmi() || in_hardirq());
/*
* After the stb, interrupts are unmasked and there are no interrupts
* pending replay. The restart sequence makes this atomic with
* respect to soft-masked interrupts. If this was just a simple code
* sequence, a soft-masked interrupt could become pending right after
* the comparison and before the stb.
*
* This allows interrupts to be unmasked without hard disabling, and
* also without new hard interrupts coming in ahead of pending ones.
*/
asm_volatile_goto(
"1: \n"
" lbz 9,%0(13) \n"
" cmpwi 9,0 \n"
" bne %l[happened] \n"
" stb 9,%1(13) \n"
"2: \n"
RESTART_TABLE(1b, 2b, 1b)
: : "i" (offsetof(struct paca_struct, irq_happened)),
"i" (offsetof(struct paca_struct, irq_soft_mask))
: "cr0", "r9"
: happened);
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(!(mfmsr() & MSR_EE));
return;
happened:
irq_happened = get_irq_happened();
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(!irq_happened);
if (irq_happened == PACA_IRQ_HARD_DIS) {
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(mfmsr() & MSR_EE);
irq_soft_mask_set(IRQS_ENABLED);
local_paca->irq_happened = 0;
__hard_irq_enable();
return;
}
/* Have interrupts to replay, need to hard disable first */
if (!(irq_happened & PACA_IRQ_HARD_DIS)) {
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
if (!(mfmsr() & MSR_EE)) {
/*
* An interrupt could have come in and cleared
* MSR[EE] and set IRQ_HARD_DIS, so check
* IRQ_HARD_DIS again and warn if it is still
* clear.
*/
irq_happened = get_irq_happened();
WARN_ON_ONCE(!(irq_happened & PACA_IRQ_HARD_DIS));
}
}
__hard_irq_disable();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
} else {
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
if (WARN_ON_ONCE(mfmsr() & MSR_EE))
__hard_irq_disable();
}
}
/*
* Disable preempt here, so that the below preempt_enable will
* perform resched if required (a replayed interrupt may set
* need_resched).
*/
preempt_disable();
irq_soft_mask_set(IRQS_ALL_DISABLED);
trace_hardirqs_off();
replay_soft_interrupts_irqrestore();
local_paca->irq_happened = 0;
trace_hardirqs_on();
irq_soft_mask_set(IRQS_ENABLED);
__hard_irq_enable();
preempt_enable();
}
#else
notrace void arch_local_irq_restore(unsigned long mask)
{
unsigned char irq_happened;
/* Write the new soft-enabled value */
irq_soft_mask_set(mask);
if (mask)
return;
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(in_nmi() || in_hardirq());
/*
* From this point onward, we can take interrupts, preempt,
* etc... unless we got hard-disabled. We check if an event
* happened. If none happened, we know we can just return.
*
* We may have preempted before the check below, in which case
* we are checking the "new" CPU instead of the old one. This
* is only a problem if an event happened on the "old" CPU.
*
* External interrupt events will have caused interrupts to
* be hard-disabled, so there is no problem, we
* cannot have preempted.
*/
irq_happened = get_irq_happened();
if (!irq_happened) {
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(!(mfmsr() & MSR_EE));
return;
}
/* We need to hard disable to replay. */
if (!(irq_happened & PACA_IRQ_HARD_DIS)) {
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(!(mfmsr() & MSR_EE));
__hard_irq_disable();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
} else {
/*
* We should already be hard disabled here. We had bugs
* where that wasn't the case so let's dbl check it and
* warn if we are wrong. Only do that when IRQ tracing
* is enabled as mfmsr() can be costly.
*/
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
if (WARN_ON_ONCE(mfmsr() & MSR_EE))
__hard_irq_disable();
}
if (irq_happened == PACA_IRQ_HARD_DIS) {
local_paca->irq_happened = 0;
__hard_irq_enable();
return;
}
}
/*
* Disable preempt here, so that the below preempt_enable will
* perform resched if required (a replayed interrupt may set
* need_resched).
*/
preempt_disable();
irq_soft_mask_set(IRQS_ALL_DISABLED);
trace_hardirqs_off();
replay_soft_interrupts_irqrestore();
local_paca->irq_happened = 0;
trace_hardirqs_on();
irq_soft_mask_set(IRQS_ENABLED);
__hard_irq_enable();
preempt_enable();
}
#endif
EXPORT_SYMBOL(arch_local_irq_restore);
/*
* This is a helper to use when about to go into idle low-power
* when the latter has the side effect of re-enabling interrupts
* (such as calling H_CEDE under pHyp).
*
* You call this function with interrupts soft-disabled (this is
* already the case when ppc_md.power_save is called). The function
* will return whether to enter power save or just return.
*
* In the former case, it will have notified lockdep of interrupts
* being re-enabled and generally sanitized the lazy irq state,
* and in the latter case it will leave with interrupts hard
* disabled and marked as such, so the local_irq_enable() call
* in arch_cpu_idle() will properly re-enable everything.
*/
bool prep_irq_for_idle(void)
{
/*
* First we need to hard disable to ensure no interrupt
* occurs before we effectively enter the low power state
*/
__hard_irq_disable();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
/*
* If anything happened while we were soft-disabled,
* we return now and do not enter the low power state.
*/
if (lazy_irq_pending())
return false;
/* Tell lockdep we are about to re-enable */
trace_hardirqs_on();
/*
* Mark interrupts as soft-enabled and clear the
* PACA_IRQ_HARD_DIS from the pending mask since we
* are about to hard enable as well as a side effect
* of entering the low power state.
*/
local_paca->irq_happened &= ~PACA_IRQ_HARD_DIS;
irq_soft_mask_set(IRQS_ENABLED);
/* Tell the caller to enter the low power state */
return true;
}
#ifdef CONFIG_PPC_BOOK3S
/*
* This is for idle sequences that return with IRQs off, but the
* idle state itself wakes on interrupt. Tell the irq tracer that
* IRQs are enabled for the duration of idle so it does not get long
* off times. Must be paired with fini_irq_for_idle_irqsoff.
*/
bool prep_irq_for_idle_irqsoff(void)
{
WARN_ON(!irqs_disabled());
/*
* First we need to hard disable to ensure no interrupt
* occurs before we effectively enter the low power state
*/
__hard_irq_disable();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
/*
* If anything happened while we were soft-disabled,
* we return now and do not enter the low power state.
*/
if (lazy_irq_pending())
return false;
/* Tell lockdep we are about to re-enable */
trace_hardirqs_on();
return true;
}
/*
* Take the SRR1 wakeup reason, index into this table to find the
* appropriate irq_happened bit.
*
* Sytem reset exceptions taken in idle state also come through here,
* but they are NMI interrupts so do not need to wait for IRQs to be
* restored, and should be taken as early as practical. These are marked
* with 0xff in the table. The Power ISA specifies 0100b as the system
* reset interrupt reason.
*/
#define IRQ_SYSTEM_RESET 0xff
static const u8 srr1_to_lazyirq[0x10] = {
0, 0, 0,
PACA_IRQ_DBELL,
IRQ_SYSTEM_RESET,
PACA_IRQ_DBELL,
PACA_IRQ_DEC,
0,
PACA_IRQ_EE,
PACA_IRQ_EE,
PACA_IRQ_HMI,
0, 0, 0, 0, 0 };
void replay_system_reset(void)
{
struct pt_regs regs;
ppc_save_regs(&regs);
regs.trap = 0x100;
get_paca()->in_nmi = 1;
system_reset_exception(&regs);
get_paca()->in_nmi = 0;
}
EXPORT_SYMBOL_GPL(replay_system_reset);
void irq_set_pending_from_srr1(unsigned long srr1)
{
unsigned int idx = (srr1 & SRR1_WAKEMASK_P8) >> 18;
u8 reason = srr1_to_lazyirq[idx];
/*
* Take the system reset now, which is immediately after registers
* are restored from idle. It's an NMI, so interrupts need not be
* re-enabled before it is taken.
*/
if (unlikely(reason == IRQ_SYSTEM_RESET)) {
replay_system_reset();
return;
}
if (reason == PACA_IRQ_DBELL) {
/*
* When doorbell triggers a system reset wakeup, the message
* is not cleared, so if the doorbell interrupt is replayed
* and the IPI handled, the doorbell interrupt would still
* fire when EE is enabled.
*
* To avoid taking the superfluous doorbell interrupt,
* execute a msgclr here before the interrupt is replayed.
*/
ppc_msgclr(PPC_DBELL_MSGTYPE);
}
/*
* The 0 index (SRR1[42:45]=b0000) must always evaluate to 0,
* so this can be called unconditionally with the SRR1 wake
* reason as returned by the idle code, which uses 0 to mean no
* interrupt.
*
* If a future CPU was to designate this as an interrupt reason,
* then a new index for no interrupt must be assigned.
*/
local_paca->irq_happened |= reason;
}
#endif /* CONFIG_PPC_BOOK3S */
/*
* Force a replay of the external interrupt handler on this CPU.
*/
void force_external_irq_replay(void)
{
/*
* This must only be called with interrupts soft-disabled,
* the replay will happen when re-enabling.
*/
WARN_ON(!arch_irqs_disabled());
/*
* Interrupts must always be hard disabled before irq_happened is
* modified (to prevent lost update in case of interrupt between
* load and store).
*/
__hard_irq_disable();
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
/* Indicate in the PACA that we have an interrupt to replay */
local_paca->irq_happened |= PACA_IRQ_EE;
}
#endif /* CONFIG_PPC64 */
int arch_show_interrupts(struct seq_file *p, int prec)
{
int j;
#if defined(CONFIG_PPC32) && defined(CONFIG_TAU_INT)
if (tau_initialized) {
seq_printf(p, "%*s: ", prec, "TAU");
for_each_online_cpu(j)
seq_printf(p, "%10u ", tau_interrupts(j));
seq_puts(p, " PowerPC Thermal Assist (cpu temp)\n");
}
#endif /* CONFIG_PPC32 && CONFIG_TAU_INT */
seq_printf(p, "%*s: ", prec, "LOC");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_event);
seq_printf(p, " Local timer interrupts for timer event device\n");
seq_printf(p, "%*s: ", prec, "BCT");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).broadcast_irqs_event);
seq_printf(p, " Broadcast timer interrupts for timer event device\n");
seq_printf(p, "%*s: ", prec, "LOC");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).timer_irqs_others);
seq_printf(p, " Local timer interrupts for others\n");
seq_printf(p, "%*s: ", prec, "SPU");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).spurious_irqs);
seq_printf(p, " Spurious interrupts\n");
seq_printf(p, "%*s: ", prec, "PMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).pmu_irqs);
seq_printf(p, " Performance monitoring interrupts\n");
seq_printf(p, "%*s: ", prec, "MCE");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).mce_exceptions);
seq_printf(p, " Machine check exceptions\n");
#ifdef CONFIG_PPC_BOOK3S_64
if (cpu_has_feature(CPU_FTR_HVMODE)) {
seq_printf(p, "%*s: ", prec, "HMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", paca_ptrs[j]->hmi_irqs);
seq_printf(p, " Hypervisor Maintenance Interrupts\n");
}
#endif
seq_printf(p, "%*s: ", prec, "NMI");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).sreset_irqs);
seq_printf(p, " System Reset interrupts\n");
#ifdef CONFIG_PPC_WATCHDOG
seq_printf(p, "%*s: ", prec, "WDG");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).soft_nmi_irqs);
seq_printf(p, " Watchdog soft-NMI interrupts\n");
#endif
#ifdef CONFIG_PPC_DOORBELL
if (cpu_has_feature(CPU_FTR_DBELL)) {
seq_printf(p, "%*s: ", prec, "DBL");
for_each_online_cpu(j)
seq_printf(p, "%10u ", per_cpu(irq_stat, j).doorbell_irqs);
seq_printf(p, " Doorbell interrupts\n");
}
#endif
return 0;
}
/*
* /proc/stat helpers
*/
u64 arch_irq_stat_cpu(unsigned int cpu)
{
u64 sum = per_cpu(irq_stat, cpu).timer_irqs_event;
sum += per_cpu(irq_stat, cpu).broadcast_irqs_event;
sum += per_cpu(irq_stat, cpu).pmu_irqs;
sum += per_cpu(irq_stat, cpu).mce_exceptions;
sum += per_cpu(irq_stat, cpu).spurious_irqs;
sum += per_cpu(irq_stat, cpu).timer_irqs_others;
#ifdef CONFIG_PPC_BOOK3S_64
sum += paca_ptrs[cpu]->hmi_irqs;
#endif
sum += per_cpu(irq_stat, cpu).sreset_irqs;
#ifdef CONFIG_PPC_WATCHDOG
sum += per_cpu(irq_stat, cpu).soft_nmi_irqs;
#endif
#ifdef CONFIG_PPC_DOORBELL
sum += per_cpu(irq_stat, cpu).doorbell_irqs;
#endif
return sum;
}
static inline void check_stack_overflow(void)
{
long sp;
if (!IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW))
return;
sp = current_stack_pointer & (THREAD_SIZE - 1);
/* check for stack overflow: is there less than 2KB free? */
if (unlikely(sp < 2048)) {
pr_err("do_IRQ: stack overflow: %ld\n", sp);
dump_stack();
}
}
static __always_inline void call_do_softirq(const void *sp)
{
/* Temporarily switch r1 to sp, call __do_softirq() then restore r1. */
asm volatile (
PPC_STLU " %%r1, %[offset](%[sp]) ;"
"mr %%r1, %[sp] ;"
"bl %[callee] ;"
PPC_LL " %%r1, 0(%%r1) ;"
: // Outputs
: // Inputs
[sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
[callee] "i" (__do_softirq)
: // Clobbers
"lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
"cr7", "r0", "r3", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
"r11", "r12"
);
}
static __always_inline void call_do_irq(struct pt_regs *regs, void *sp)
{
register unsigned long r3 asm("r3") = (unsigned long)regs;
/* Temporarily switch r1 to sp, call __do_irq() then restore r1. */
asm volatile (
PPC_STLU " %%r1, %[offset](%[sp]) ;"
"mr %%r1, %[sp] ;"
"bl %[callee] ;"
PPC_LL " %%r1, 0(%%r1) ;"
: // Outputs
"+r" (r3)
: // Inputs
[sp] "b" (sp), [offset] "i" (THREAD_SIZE - STACK_FRAME_OVERHEAD),
[callee] "i" (__do_irq)
: // Clobbers
"lr", "xer", "ctr", "memory", "cr0", "cr1", "cr5", "cr6",
"cr7", "r0", "r4", "r5", "r6", "r7", "r8", "r9", "r10",
"r11", "r12"
);
}
void __do_irq(struct pt_regs *regs)
{
unsigned int irq;
trace_irq_entry(regs);
/*
* Query the platform PIC for the interrupt & ack it.
*
* This will typically lower the interrupt line to the CPU
*/
irq = ppc_md.get_irq();
/* We can hard enable interrupts now to allow perf interrupts */
may_hard_irq_enable();
/* And finally process it */
if (unlikely(!irq))
__this_cpu_inc(irq_stat.spurious_irqs);
else
generic_handle_irq(irq);
trace_irq_exit(regs);
}
void __do_IRQ(struct pt_regs *regs)
{
struct pt_regs *old_regs = set_irq_regs(regs);
void *cursp, *irqsp, *sirqsp;
/* Switch to the irq stack to handle this */
cursp = (void *)(current_stack_pointer & ~(THREAD_SIZE - 1));
irqsp = hardirq_ctx[raw_smp_processor_id()];
sirqsp = softirq_ctx[raw_smp_processor_id()];
check_stack_overflow();
/* Already there ? */
if (unlikely(cursp == irqsp || cursp == sirqsp)) {
__do_irq(regs);
set_irq_regs(old_regs);
return;
}
/* Switch stack and call */
call_do_irq(regs, irqsp);
set_irq_regs(old_regs);
}
DEFINE_INTERRUPT_HANDLER_ASYNC(do_IRQ)
{
__do_IRQ(regs);
}
static void *__init alloc_vm_stack(void)
{
return __vmalloc_node(THREAD_SIZE, THREAD_ALIGN, THREADINFO_GFP,
NUMA_NO_NODE, (void *)_RET_IP_);
}
static void __init vmap_irqstack_init(void)
{
int i;
for_each_possible_cpu(i) {
softirq_ctx[i] = alloc_vm_stack();
hardirq_ctx[i] = alloc_vm_stack();
}
}
void __init init_IRQ(void)
{
if (IS_ENABLED(CONFIG_VMAP_STACK))
vmap_irqstack_init();
if (ppc_md.init_IRQ)
ppc_md.init_IRQ();
}
#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
void *critirq_ctx[NR_CPUS] __read_mostly;
void *dbgirq_ctx[NR_CPUS] __read_mostly;
void *mcheckirq_ctx[NR_CPUS] __read_mostly;
#endif
void *softirq_ctx[NR_CPUS] __read_mostly;
void *hardirq_ctx[NR_CPUS] __read_mostly;
void do_softirq_own_stack(void)
{
call_do_softirq(softirq_ctx[smp_processor_id()]);
}
irq_hw_number_t virq_to_hw(unsigned int virq)
{
struct irq_data *irq_data = irq_get_irq_data(virq);
return WARN_ON(!irq_data) ? 0 : irq_data->hwirq;
}
EXPORT_SYMBOL_GPL(virq_to_hw);
#ifdef CONFIG_SMP
int irq_choose_cpu(const struct cpumask *mask)
{
int cpuid;
if (cpumask_equal(mask, cpu_online_mask)) {
static int irq_rover;
static DEFINE_RAW_SPINLOCK(irq_rover_lock);
unsigned long flags;
/* Round-robin distribution... */
do_round_robin:
raw_spin_lock_irqsave(&irq_rover_lock, flags);
irq_rover = cpumask_next(irq_rover, cpu_online_mask);
if (irq_rover >= nr_cpu_ids)
irq_rover = cpumask_first(cpu_online_mask);
cpuid = irq_rover;
raw_spin_unlock_irqrestore(&irq_rover_lock, flags);
} else {
cpuid = cpumask_first_and(mask, cpu_online_mask);
if (cpuid >= nr_cpu_ids)
goto do_round_robin;
}
return get_hard_smp_processor_id(cpuid);
}
#else
int irq_choose_cpu(const struct cpumask *mask)
{
return hard_smp_processor_id();
}
#endif
#ifdef CONFIG_PPC64
static int __init setup_noirqdistrib(char *str)
{
distribute_irqs = 0;
return 1;
}
__setup("noirqdistrib", setup_noirqdistrib);
#endif /* CONFIG_PPC64 */