Move the IRQ stub generation to assembly to simplify it and for
consistency with 32 bits. Doing it in a C file with asm() statements
doesn't help clarity, and it prevents some optimizations.
Shrink the IRQ stubs down to just over four bytes per (we fit seven
into a 32-byte chunk.) This shrinks the total icache consumption of
the IRQ stubs down to an even kilobyte, if all of them are in active
use.
The downside is that we end up with a double jump, which could have a
negative effect on some pipelines. The double jump is always inside
the same cacheline on any modern chips.
To get the most effect, cache-align the IRQ stubs.
This makes the 64-bit code match changes already done to the 32-bit
code, and should open up irqinit*.c for unification.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
change names:
irq_desc() ==> irq_desc_alloc
__irq_desc() ==> irq_desc
Also split a few of the uses in lowlevel x86 code.
v2: need to check if desc is null in smp_irq_move_cleanup
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
There are a handful of loops that go from 0 to nr_irqs and use
get_irq_desc() on them. These would allocate all the irq_desc
entries, regardless of the need for them.
Use the smarter for_each_irq_desc() iterator that will only iterate
over the present ones.
v2: make sure arch without GENERIC_HARDIRQS work too
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
add CONFIG_HAVE_SPARSE_IRQ to for use condensed array.
Get rid of irq_desc[] array assumptions.
Preallocate 32 irq_desc, and irq_desc() will try to get more.
( No change in functionality is expected anywhere, except the odd build
failure where we missed a code site or where a crossing commit itroduces
new irq_desc[] usage. )
v2: according to Eric, change get_irq_desc() to irq_desc()
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
also add first_free_entry and pin_map_size, which were NR_IRQS derived
constants.
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Commit 9d25d4db81 ("x86: BUILD_IRQ say
.text to avoid .data.percpu") added a ".text" specifier to make sure
that BUILD_IRQ() builds the irq trampoline in the text segment rather
than in some random left-over segment that the compiler happened to
leave the asm in.
However, we should also make sure that we switch back by adding a
".previous" at the end, so that there are no subtle issues with
subsequent compiler-generated code.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When I edit the x86_64 Makefile to -fno-unit-at-a-time, bootup panics
on 0xCCs in IRQ0x3e_interrupt(): IRQ0x20_interrupt etc. have got linked
into .data.percpu. Perhaps there are other ways of triggering that:
specify ".text" in the BUILD_IRQ() macro for safety.
I've been using -fno-unit-at-a-time (to lessen inlining, for easier
debugging) for a long time.
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Cc: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The leftovers of the i8259 unification have nothing to do with i8259
at all. They contain interrupt init code and the i8259_xx name is just
misleading now.
Rename them to irqinit_32/64.c
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
