Re: [PATCH] ftrace: handle archs that do not support irqs_disabled_flags

From: Geert Uytterhoeven
Date: Sat Oct 25 2008 - 04:24:40 EST


On Fri, 24 Oct 2008, Steven Rostedt wrote:
> Some architectures do not support a way to read the irq flags that
> is set from "local_irq_save(flags)" to determine if interrupts were
> disabled or enabled. Ftrace uses this information to display to the user
> if the trace occurred with interrupts enabled or disabled.

Both alpha

#define irqs_disabled() (getipl() == IPL_MAX)

and m68k

static inline int irqs_disabled(void)
{
unsigned long flags;
local_save_flags(flags);
return flags & ~ALLOWINT;
}

do have irqs_disabled(), but they don't have irqs_disabled_flags().

M68knommu has both, but they don't check the same thing:

#define irqs_disabled() \
({ \
unsigned long flags; \
local_save_flags(flags); \
((flags & 0x0700) == 0x0700); \
})

static inline int irqs_disabled_flags(unsigned long flags)
{
if (flags & 0x0700)
return 0;
else
return 1;
}

Is there a semantic difference between them (except that the latter takes the
flags as a parameter)?

Or can we just extract the core logic of irqs_disabled() into
irqs_disabled_flags()?

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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