Re: [PATCH 02/15] irq: mips: stop (ab)using handle_domain_irq()

[Thomas Bogendoerfer]

On Thu, Oct 21, 2021 at 07:02:23PM +0100, Mark Rutland wrote:
> On MIPS, the only user of handle_domain_irq() is octeon_irq_ciu3_ip2(),
> which is called from the platform-specific plat_irq_dispatch() function
> invoked from the early assembly code.
> 
> No other irqchip relevant to arch/mips uses handle_domain_irq():
> 
> * No other plat_irq_dispatch() function transitively calls
>   handle_domain_irq().
> 
> * No other vectored IRQ dispatch function registered with
>   set_vi_handler() calls handle_domain_irq().
> 
> * No chained irqchip handlers call handle_domain_irq(), which makes
>   sense as this is meant to only be used by root irqchip handlers.
> 
> Currently octeon_irq_ciu3_ip2() passes NULL as the `regs` argument to
> handle_domain_irq(), and as handle_domain_irq() will pass this to
> set_irq_regs(), any invoked IRQ handlers will erroneously see a NULL
> pt_regs if they call get_pt_regs().
> 
> Fix this by calling generic_handle_domain_irq() directly, and performing
> the necessary irq_{enter,exit}() logic directly in
> octeon_irq_ciu3_ip2(). At the same time, deselect HANDLE_DOMAIN_IRQ,
> which subsequent patches will remove.
> 
> Other than the corrected behaviour of get_pt_regs(), there should be no
> functional change as a result of this patch.
> 
> Fixes: ce210d35bb93c2c5 ("MIPS: OCTEON: Add support for OCTEON III interrupt controller.")
> Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> ---
>  arch/mips/Kconfig                    | 1 -
>  arch/mips/cavium-octeon/octeon-irq.c | 5 ++++-
>  2 files changed, 4 insertions(+), 2 deletions(-)

Acked-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>

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