linux-zen-server/arch/powerpc/include/asm/hw_irq.h

522 lines
13 KiB
C
Raw Permalink Normal View History

2023-08-30 17:53:23 +02:00
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 1999 Cort Dougan <cort@cs.nmt.edu>
*/
#ifndef _ASM_POWERPC_HW_IRQ_H
#define _ASM_POWERPC_HW_IRQ_H
#ifdef __KERNEL__
#include <linux/errno.h>
#include <linux/compiler.h>
#include <asm/ptrace.h>
#include <asm/processor.h>
#ifdef CONFIG_PPC64
/*
* PACA flags in paca->irq_happened.
*
* This bits are set when interrupts occur while soft-disabled
* and allow a proper replay.
*
* The PACA_IRQ_HARD_DIS is set whenever we hard disable. It is almost
* always in synch with the MSR[EE] state, except:
* - A window in interrupt entry, where hardware disables MSR[EE] and that
* must be "reconciled" with the soft mask state.
* - NMI interrupts that hit in awkward places, until they fix the state.
* - When local irqs are being enabled and state is being fixed up.
* - When returning from an interrupt there are some windows where this
* can become out of synch, but gets fixed before the RFI or before
* executing the next user instruction (see arch/powerpc/kernel/interrupt.c).
*/
#define PACA_IRQ_HARD_DIS 0x01
#define PACA_IRQ_DBELL 0x02
#define PACA_IRQ_EE 0x04
#define PACA_IRQ_DEC 0x08 /* Or FIT */
#define PACA_IRQ_HMI 0x10
#define PACA_IRQ_PMI 0x20
#define PACA_IRQ_REPLAYING 0x40
/*
* Some soft-masked interrupts must be hard masked until they are replayed
* (e.g., because the soft-masked handler does not clear the exception).
* Interrupt replay itself must remain hard masked too.
*/
#ifdef CONFIG_PPC_BOOK3S
#define PACA_IRQ_MUST_HARD_MASK (PACA_IRQ_EE|PACA_IRQ_PMI|PACA_IRQ_REPLAYING)
#else
#define PACA_IRQ_MUST_HARD_MASK (PACA_IRQ_EE|PACA_IRQ_REPLAYING)
#endif
#endif /* CONFIG_PPC64 */
/*
* flags for paca->irq_soft_mask
*/
#define IRQS_ENABLED 0
#define IRQS_DISABLED 1 /* local_irq_disable() interrupts */
#define IRQS_PMI_DISABLED 2
#define IRQS_ALL_DISABLED (IRQS_DISABLED | IRQS_PMI_DISABLED)
#ifndef __ASSEMBLY__
static inline void __hard_irq_enable(void)
{
if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
wrtee(MSR_EE);
else if (IS_ENABLED(CONFIG_PPC_8xx))
wrtspr(SPRN_EIE);
else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
__mtmsrd(MSR_EE | MSR_RI, 1);
else
mtmsr(mfmsr() | MSR_EE);
}
static inline void __hard_irq_disable(void)
{
if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
wrtee(0);
else if (IS_ENABLED(CONFIG_PPC_8xx))
wrtspr(SPRN_EID);
else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
__mtmsrd(MSR_RI, 1);
else
mtmsr(mfmsr() & ~MSR_EE);
}
static inline void __hard_EE_RI_disable(void)
{
if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
wrtee(0);
else if (IS_ENABLED(CONFIG_PPC_8xx))
wrtspr(SPRN_NRI);
else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
__mtmsrd(0, 1);
else
mtmsr(mfmsr() & ~(MSR_EE | MSR_RI));
}
static inline void __hard_RI_enable(void)
{
if (IS_ENABLED(CONFIG_BOOKE_OR_40x))
return;
if (IS_ENABLED(CONFIG_PPC_8xx))
wrtspr(SPRN_EID);
else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
__mtmsrd(MSR_RI, 1);
else
mtmsr(mfmsr() | MSR_RI);
}
#ifdef CONFIG_PPC64
#include <asm/paca.h>
static inline notrace unsigned long irq_soft_mask_return(void)
{
unsigned long flags;
asm volatile(
"lbz %0,%1(13)"
: "=r" (flags)
: "i" (offsetof(struct paca_struct, irq_soft_mask)));
return flags;
}
/*
* The "memory" clobber acts as both a compiler barrier
* for the critical section and as a clobber because
* we changed paca->irq_soft_mask
*/
static inline notrace void irq_soft_mask_set(unsigned long mask)
{
/*
* The irq mask must always include the STD bit if any are set.
*
* and interrupts don't get replayed until the standard
* interrupt (local_irq_disable()) is unmasked.
*
* Other masks must only provide additional masking beyond
* the standard, and they are also not replayed until the
* standard interrupt becomes unmasked.
*
* This could be changed, but it will require partial
* unmasks to be replayed, among other things. For now, take
* the simple approach.
*/
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON(mask && !(mask & IRQS_DISABLED));
asm volatile(
"stb %0,%1(13)"
:
: "r" (mask),
"i" (offsetof(struct paca_struct, irq_soft_mask))
: "memory");
}
static inline notrace unsigned long irq_soft_mask_set_return(unsigned long mask)
{
unsigned long flags = irq_soft_mask_return();
irq_soft_mask_set(mask);
return flags;
}
static inline notrace unsigned long irq_soft_mask_or_return(unsigned long mask)
{
unsigned long flags = irq_soft_mask_return();
irq_soft_mask_set(flags | mask);
return flags;
}
static inline notrace unsigned long irq_soft_mask_andc_return(unsigned long mask)
{
unsigned long flags = irq_soft_mask_return();
irq_soft_mask_set(flags & ~mask);
return flags;
}
static inline unsigned long arch_local_save_flags(void)
{
return irq_soft_mask_return();
}
static inline void arch_local_irq_disable(void)
{
irq_soft_mask_set(IRQS_DISABLED);
}
extern void arch_local_irq_restore(unsigned long);
static inline void arch_local_irq_enable(void)
{
arch_local_irq_restore(IRQS_ENABLED);
}
static inline unsigned long arch_local_irq_save(void)
{
return irq_soft_mask_or_return(IRQS_DISABLED);
}
static inline bool arch_irqs_disabled_flags(unsigned long flags)
{
return flags & IRQS_DISABLED;
}
static inline bool arch_irqs_disabled(void)
{
return arch_irqs_disabled_flags(arch_local_save_flags());
}
static inline void set_pmi_irq_pending(void)
{
/*
* Invoked from PMU callback functions to set PMI bit in the paca.
* This has to be called with irq's disabled (via hard_irq_disable()).
*/
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(mfmsr() & MSR_EE);
get_paca()->irq_happened |= PACA_IRQ_PMI;
}
static inline void clear_pmi_irq_pending(void)
{
/*
* Invoked from PMU callback functions to clear the pending PMI bit
* in the paca.
*/
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
WARN_ON_ONCE(mfmsr() & MSR_EE);
get_paca()->irq_happened &= ~PACA_IRQ_PMI;
}
static inline bool pmi_irq_pending(void)
{
/*
* Invoked from PMU callback functions to check if there is a pending
* PMI bit in the paca.
*/
if (get_paca()->irq_happened & PACA_IRQ_PMI)
return true;
return false;
}
#ifdef CONFIG_PPC_BOOK3S
/*
* To support disabling and enabling of irq with PMI, set of
* new powerpc_local_irq_pmu_save() and powerpc_local_irq_restore()
* functions are added. These macros are implemented using generic
* linux local_irq_* code from include/linux/irqflags.h.
*/
#define raw_local_irq_pmu_save(flags) \
do { \
typecheck(unsigned long, flags); \
flags = irq_soft_mask_or_return(IRQS_DISABLED | \
IRQS_PMI_DISABLED); \
} while(0)
#define raw_local_irq_pmu_restore(flags) \
do { \
typecheck(unsigned long, flags); \
arch_local_irq_restore(flags); \
} while(0)
#ifdef CONFIG_TRACE_IRQFLAGS
#define powerpc_local_irq_pmu_save(flags) \
do { \
raw_local_irq_pmu_save(flags); \
if (!raw_irqs_disabled_flags(flags)) \
trace_hardirqs_off(); \
} while(0)
#define powerpc_local_irq_pmu_restore(flags) \
do { \
if (!raw_irqs_disabled_flags(flags)) \
trace_hardirqs_on(); \
raw_local_irq_pmu_restore(flags); \
} while(0)
#else
#define powerpc_local_irq_pmu_save(flags) \
do { \
raw_local_irq_pmu_save(flags); \
} while(0)
#define powerpc_local_irq_pmu_restore(flags) \
do { \
raw_local_irq_pmu_restore(flags); \
} while (0)
#endif /* CONFIG_TRACE_IRQFLAGS */
#endif /* CONFIG_PPC_BOOK3S */
#define hard_irq_disable() do { \
unsigned long flags; \
__hard_irq_disable(); \
flags = irq_soft_mask_set_return(IRQS_ALL_DISABLED); \
local_paca->irq_happened |= PACA_IRQ_HARD_DIS; \
if (!arch_irqs_disabled_flags(flags)) { \
asm volatile("std%X0 %1,%0" : "=m" (local_paca->saved_r1) \
: "r" (current_stack_pointer)); \
trace_hardirqs_off(); \
} \
} while(0)
static inline bool __lazy_irq_pending(u8 irq_happened)
{
return !!(irq_happened & ~PACA_IRQ_HARD_DIS);
}
/*
* Check if a lazy IRQ is pending. Should be called with IRQs hard disabled.
*/
static inline bool lazy_irq_pending(void)
{
return __lazy_irq_pending(get_paca()->irq_happened);
}
/*
* Check if a lazy IRQ is pending, with no debugging checks.
* Should be called with IRQs hard disabled.
* For use in RI disabled code or other constrained situations.
*/
static inline bool lazy_irq_pending_nocheck(void)
{
return __lazy_irq_pending(local_paca->irq_happened);
}
bool power_pmu_wants_prompt_pmi(void);
/*
* This is called by asynchronous interrupts to check whether to
* conditionally re-enable hard interrupts after having cleared
* the source of the interrupt. They are kept disabled if there
* is a different soft-masked interrupt pending that requires hard
* masking.
*/
static inline bool should_hard_irq_enable(struct pt_regs *regs)
{
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG)) {
WARN_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
WARN_ON(!(get_paca()->irq_happened & PACA_IRQ_HARD_DIS));
WARN_ON(mfmsr() & MSR_EE);
}
if (!IS_ENABLED(CONFIG_PERF_EVENTS))
return false;
/*
* If the PMU is not running, there is not much reason to enable
* MSR[EE] in irq handlers because any interrupts would just be
* soft-masked.
*
* TODO: Add test for 64e
*/
if (IS_ENABLED(CONFIG_PPC_BOOK3S_64)) {
if (!power_pmu_wants_prompt_pmi())
return false;
/*
* If PMIs are disabled then IRQs should be disabled as well,
* so we shouldn't see this condition, check for it just in
* case because we are about to enable PMIs.
*/
if (WARN_ON_ONCE(regs->softe & IRQS_PMI_DISABLED))
return false;
}
if (get_paca()->irq_happened & PACA_IRQ_MUST_HARD_MASK)
return false;
return true;
}
/*
* Do the hard enabling, only call this if should_hard_irq_enable is true.
* This allows PMI interrupts to profile irq handlers.
*/
static inline void do_hard_irq_enable(void)
{
/*
* Asynch interrupts come in with IRQS_ALL_DISABLED,
* PACA_IRQ_HARD_DIS, and MSR[EE]=0.
*/
if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
irq_soft_mask_andc_return(IRQS_PMI_DISABLED);
get_paca()->irq_happened &= ~PACA_IRQ_HARD_DIS;
__hard_irq_enable();
}
static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
{
return (regs->softe & IRQS_DISABLED);
}
extern bool prep_irq_for_idle(void);
extern bool prep_irq_for_idle_irqsoff(void);
extern void irq_set_pending_from_srr1(unsigned long srr1);
#define fini_irq_for_idle_irqsoff() trace_hardirqs_off();
extern void force_external_irq_replay(void);
static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
{
regs->softe = val;
}
#else /* CONFIG_PPC64 */
static inline notrace unsigned long irq_soft_mask_return(void)
{
return 0;
}
static inline unsigned long arch_local_save_flags(void)
{
return mfmsr();
}
static inline void arch_local_irq_restore(unsigned long flags)
{
if (IS_ENABLED(CONFIG_BOOKE))
wrtee(flags);
else
mtmsr(flags);
}
static inline unsigned long arch_local_irq_save(void)
{
unsigned long flags = arch_local_save_flags();
if (IS_ENABLED(CONFIG_BOOKE))
wrtee(0);
else if (IS_ENABLED(CONFIG_PPC_8xx))
wrtspr(SPRN_EID);
else
mtmsr(flags & ~MSR_EE);
return flags;
}
static inline void arch_local_irq_disable(void)
{
__hard_irq_disable();
}
static inline void arch_local_irq_enable(void)
{
__hard_irq_enable();
}
static inline bool arch_irqs_disabled_flags(unsigned long flags)
{
return (flags & MSR_EE) == 0;
}
static inline bool arch_irqs_disabled(void)
{
return arch_irqs_disabled_flags(arch_local_save_flags());
}
#define hard_irq_disable() arch_local_irq_disable()
static inline bool arch_irq_disabled_regs(struct pt_regs *regs)
{
return !(regs->msr & MSR_EE);
}
static __always_inline bool should_hard_irq_enable(struct pt_regs *regs)
{
return false;
}
static inline void do_hard_irq_enable(void)
{
BUILD_BUG();
}
static inline void clear_pmi_irq_pending(void) { }
static inline void set_pmi_irq_pending(void) { }
static inline bool pmi_irq_pending(void) { return false; }
static inline void irq_soft_mask_regs_set_state(struct pt_regs *regs, unsigned long val)
{
}
#endif /* CONFIG_PPC64 */
static inline unsigned long mtmsr_isync_irqsafe(unsigned long msr)
{
#ifdef CONFIG_PPC64
if (arch_irqs_disabled()) {
/*
* With soft-masking, MSR[EE] can change from 1 to 0
* asynchronously when irqs are disabled, and we don't want to
* set MSR[EE] back to 1 here if that has happened. A race-free
* way to do this is ensure EE is already 0. Another way it
* could be done is with a RESTART_TABLE handler, but that's
* probably overkill here.
*/
msr &= ~MSR_EE;
mtmsr_isync(msr);
irq_soft_mask_set(IRQS_ALL_DISABLED);
local_paca->irq_happened |= PACA_IRQ_HARD_DIS;
} else
#endif
mtmsr_isync(msr);
return msr;
}
#define ARCH_IRQ_INIT_FLAGS IRQ_NOREQUEST
#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_HW_IRQ_H */