In preparation for reworking the EL1 irq/nmi entry code, move the
existing logic to C. We no longer need the asm_nmi_enter() and
asm_nmi_exit() wrappers, so these are removed. The new C functions are
marked noinstr, which prevents compiler instrumentation and runtime
probing.
In subsequent patches we'll want the new C helpers to be called in all
cases, so we don't bother wrapping the calls with ifdeferry. Even when
the new C functions are stubs the trivial calls are unlikely to have a
measurable impact on the IRQ or NMI paths anyway.
Prototypes are added to <asm/exception.h> as otherwise (in some
configurations) GCC will complain about the lack of a forward
declaration. We already do this for existing function, e.g.
enter_from_user_mode().
The new helpers are marked as noinstr (which prevents all
instrumentation, tracing, and kprobes). Otherwise, there should be no
functional change as a result of this patch.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20201130115950.22492-7-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
return esr;
}
+asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs);
+asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs);
asmlinkage void enter_from_user_mode(void);
void do_mem_abort(unsigned long addr, unsigned int esr, struct pt_regs *regs);
void do_undefinstr(struct pt_regs *regs);
#include <asm/mmu.h>
#include <asm/sysreg.h>
+asmlinkage void noinstr enter_el1_irq_or_nmi(struct pt_regs *regs)
+{
+ if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs))
+ nmi_enter();
+
+ trace_hardirqs_off();
+}
+
+asmlinkage void noinstr exit_el1_irq_or_nmi(struct pt_regs *regs)
+{
+ if (IS_ENABLED(CONFIG_ARM64_PSEUDO_NMI) && !interrupts_enabled(regs))
+ nmi_exit();
+ else
+ trace_hardirqs_on();
+}
+
static void noinstr el1_abort(struct pt_regs *regs, unsigned long esr)
{
unsigned long far = read_sysreg(far_el1);
gic_prio_irq_setup pmr=x20, tmp=x1
enable_da_f
-#ifdef CONFIG_ARM64_PSEUDO_NMI
- test_irqs_unmasked res=x0, pmr=x20
- cbz x0, 1f
- bl asm_nmi_enter
-1:
-#endif
-
-#ifdef CONFIG_TRACE_IRQFLAGS
- bl trace_hardirqs_off
-#endif
+ mov x0, sp
+ bl enter_el1_irq_or_nmi
irq_handler
1:
#endif
-#ifdef CONFIG_ARM64_PSEUDO_NMI
- /*
- * When using IRQ priority masking, we can get spurious interrupts while
- * PMR is set to GIC_PRIO_IRQOFF. An NMI might also have occurred in a
- * section with interrupts disabled. Skip tracing in those cases.
- */
- test_irqs_unmasked res=x0, pmr=x20
- cbz x0, 1f
- bl asm_nmi_exit
-1:
-#endif
-
-#ifdef CONFIG_TRACE_IRQFLAGS
-#ifdef CONFIG_ARM64_PSEUDO_NMI
- test_irqs_unmasked res=x0, pmr=x20
- cbnz x0, 1f
-#endif
- bl trace_hardirqs_on
-1:
-#endif
+ mov x0, sp
+ bl exit_el1_irq_or_nmi
kernel_exit 1
SYM_CODE_END(el1_irq)
local_daif_restore(DAIF_PROCCTX_NOIRQ);
}
}
-
-/*
- * Stubs to make nmi_enter/exit() code callable from ASM
- */
-asmlinkage void notrace asm_nmi_enter(void)
-{
- nmi_enter();
-}
-NOKPROBE_SYMBOL(asm_nmi_enter);
-
-asmlinkage void notrace asm_nmi_exit(void)
-{
- nmi_exit();
-}
-NOKPROBE_SYMBOL(asm_nmi_exit);