Re: [PATCH 6/6] x86-64: Support for multiple MSIs

From: Ingo Molnar
Date: Sat Jul 12 2008 - 01:56:59 EST



* Matthew Wilcox <matthew@xxxxxx> wrote:

> Add support for allocating an aligned block of interrupt vectors.
> Allow interrupts to have up to 32 subchannels. Implement the
> arch_setup_msi_irqs() and arch_teardown_msi_irqs() interfaces.
>
> Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
> ---
> arch/x86/kernel/io_apic_64.c | 221 +++++++++++++++++++++++++++++++++++------
> arch/x86/kernel/irq_64.c | 2 +-
> include/asm-x86/irq_64.h | 2 +
> 3 files changed, 191 insertions(+), 34 deletions(-)

hm, please implement this symmetrically on 64-bit and 32-bit as well.
That will need more IRQ infrastructure changes but that should be OK as
it will reduce the gap between the 32-bit and 64-bit side instead of
widening it. A good starting point would be to unify/generalize the IRQ
vector allocators. (and that would get most of what you need for
multi-vector MSI)

Ingo
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