Le 14/12/2025 à 14:02, Mukesh Kumar Chaurasiya a écrit :
From: Mukesh Kumar Chaurasiya <[email protected]>
Enable the generic IRQ entry/exit infrastructure on PowerPC by selecting
GENERIC_IRQ_ENTRY and integrating the architecture-specific interrupt
handlers with the generic entry/exit APIs.
This change replaces PowerPC’s local interrupt entry/exit handling with
calls to the generic irqentry_* helpers, aligning the architecture with
the common kernel entry model. The macros that define interrupt, async,
and NMI handlers are updated to use irqentry_enter()/irqentry_exit()
and irqentry_nmi_enter()/irqentry_nmi_exit() where applicable.
Key updates include:
- Select GENERIC_IRQ_ENTRY in Kconfig.
- Replace interrupt_enter/exit_prepare() with arch_interrupt_* helpers.
- Integrate irqentry_enter()/exit() in standard and async interrupt paths.
- Integrate irqentry_nmi_enter()/exit() in NMI handlers.
- Remove redundant irq_enter()/irq_exit() calls now handled generically.
- Use irqentry_exit_cond_resched() for preemption checks.
This change establishes the necessary wiring for PowerPC to use the
generic IRQ entry/exit framework while maintaining existing semantics.
Did you look into resulting code ?
do_IRQ() is bigger and calls irqentry_enter() which is bigger than
irq_enter().
And irq_enter_rcu() was tail-called from irq_enter(), now is it called
after irqentry_enter().
Signed-off-by: Mukesh Kumar Chaurasiya <[email protected]>
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/entry-common.h | 66 +---
arch/powerpc/include/asm/interrupt.h | 499 +++---------------------
arch/powerpc/kernel/interrupt.c | 13 +-
4 files changed, 74 insertions(+), 505 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index e24f4d88885a..b0c602c3bbe1 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -206,6 +206,7 @@ config PPC
select GENERIC_GETTIMEOFDAY
select GENERIC_IDLE_POLL_SETUP
select GENERIC_IOREMAP
+ select GENERIC_IRQ_ENTRY
select GENERIC_IRQ_SHOW
select GENERIC_IRQ_SHOW_LEVEL
select GENERIC_PCI_IOMAP if PCI
diff --git a/arch/powerpc/include/asm/entry-common.h
b/arch/powerpc/include/asm/entry-common.h
index e8bde4c67eaf..e2ae7416dee1 100644
--- a/arch/powerpc/include/asm/entry-common.h
+++ b/arch/powerpc/include/asm/entry-common.h
@@ -257,6 +257,17 @@ static inline void arch_interrupt_enter_prepare(struct
pt_regs *regs)
*/
static inline void arch_interrupt_exit_prepare(struct pt_regs *regs)
{
+ if (user_mode(regs)) {
+ BUG_ON(regs_is_unrecoverable(regs));
+ BUG_ON(regs_irqs_disabled(regs));
+ /*
+ * We don't need to restore AMR on the way back to userspace
for KUAP.
+ * AMR can only have been unlocked if we interrupted the kernel.
+ */
+ kuap_assert_locked();
+
+ local_irq_disable();
+ }
}
static inline void arch_interrupt_async_enter_prepare(struct pt_regs *regs)
@@ -275,7 +286,6 @@ static inline void
arch_interrupt_async_enter_prepare(struct pt_regs *regs)
!test_thread_local_flags(_TLF_RUNLATCH))
__ppc64_runlatch_on();
#endif
- irq_enter();
}
static inline void arch_interrupt_async_exit_prepare(struct pt_regs *regs)
@@ -288,7 +298,6 @@ static inline void arch_interrupt_async_exit_prepare(struct
pt_regs *regs)
*/
nap_adjust_return(regs);
- irq_exit();
arch_interrupt_exit_prepare(regs);
}
@@ -354,59 +363,11 @@ static inline void arch_interrupt_nmi_enter_prepare(struct pt_regs *regs,
this_cpu_set_ftrace_enabled(0);
}
#endif
-
- /* If data relocations are enabled, it's safe to use nmi_enter() */
- if (mfmsr() & MSR_DR) {
- nmi_enter();
- return;
- }
-
- /*
- * But do not use nmi_enter() for pseries hash guest taking a real-mode
- * NMI because not everything it touches is within the RMA limit.
- */
- if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&
- firmware_has_feature(FW_FEATURE_LPAR) &&
- !radix_enabled())
- return;
-
- /*
- * Likewise, don't use it if we have some form of instrumentation (like
- * KASAN shadow) that is not safe to access in real mode (even on radix)
- */
- if (IS_ENABLED(CONFIG_KASAN))
- return;
-
- /*
- * Likewise, do not use it in real mode if percpu first chunk is not
- * embedded. With CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK enabled there
- * are chances where percpu allocation can come from vmalloc area.
- */
- if (percpu_first_chunk_is_paged)
- return;
-
- /* Otherwise, it should be safe to call it */
- nmi_enter();
}
static inline void arch_interrupt_nmi_exit_prepare(struct pt_regs *regs,
struct interrupt_nmi_state *state)
{
- if (mfmsr() & MSR_DR) {
- // nmi_exit if relocations are on
- nmi_exit();
- } else if (IS_ENABLED(CONFIG_PPC_BOOK3S_64) &&
- firmware_has_feature(FW_FEATURE_LPAR) &&
- !radix_enabled()) {
- // no nmi_exit for a pseries hash guest taking a real mode
exception
- } else if (IS_ENABLED(CONFIG_KASAN)) {
- // no nmi_exit for KASAN in real mode
- } else if (percpu_first_chunk_is_paged) {
- // no nmi_exit if percpu first chunk is not embedded
- } else {
- nmi_exit();
- }
-
/*
* nmi does not call nap_adjust_return because nmi should not create
* new work to do (must use irq_work for that).
@@ -435,6 +396,8 @@ static inline void arch_interrupt_nmi_exit_prepare(struct
pt_regs *regs,
static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs)
{
+ kuap_lock();
+
A reason why this change comes now and not in the patch that added
arch_enter_from_user_mode() ?
if (IS_ENABLED(CONFIG_PPC_IRQ_SOFT_MASK_DEBUG))
BUG_ON(irq_soft_mask_return() != IRQS_ALL_DISABLED);
@@ -467,11 +430,8 @@ static __always_inline void arch_enter_from_user_mode(struct pt_regs *regs)
} else
#endif
kuap_assert_locked();
-
booke_restore_dbcr0();
-
This is cosmetic, should have been done when adding
arch_enter_from_user_mode()
account_cpu_user_entry();
-
account_stolen_time();
/*
Christophe
