linux-kernel - [irqchip: irq/irqchip-next] irq: mips: stop (ab)using handle_domain

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Date:   Tue, 26 Oct 2021 10:16:09 -0000
From:   "irqchip-bot for Mark Rutland" <tip-bot2@...utronix.de>
To:     linux-kernel@...r.kernel.org
Cc:     Mark Rutland <mark.rutland@....com>, Marc Zyngier <maz@...nel.org>,
        Thomas Bogendoerfer <tsbogend@...ha.franken.de>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [irqchip: irq/irqchip-next] irq: mips: stop (ab)using handle_domain_irq()

The following commit has been merged into the irq/irqchip-next branch of irqchip:

Commit-ID:     bab4ff1edccd5853c956ac72e5152b073a237b50
Gitweb:        https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms/bab4ff1edccd5853c956ac72e5152b073a237b50
Author:        Mark Rutland <mark.rutland@....com>
AuthorDate:    Wed, 20 Oct 2021 15:24:40 +01:00
Committer:     Mark Rutland <mark.rutland@....com>
CommitterDate: Mon, 25 Oct 2021 10:05:07 +01:00

irq: mips: stop (ab)using handle_domain_irq()

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@....com>
Reviewed-by: Marc Zyngier <maz@...nel.org>
Acked-by: Thomas Bogendoerfer <tsbogend@...ha.franken.de>
Cc: Thomas Gleixner <tglx@...utronix.de>
---
 arch/mips/Kconfig                    | 1 -
 arch/mips/cavium-octeon/octeon-irq.c | 5 ++++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 771ca53..7b004c5 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -47,7 +47,6 @@ config MIPS
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
-	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
 	select HAVE_ARCH_JUMP_LABEL
 	select HAVE_ARCH_KGDB if MIPS_FP_SUPPORT
diff --git a/arch/mips/cavium-octeon/octeon-irq.c b/arch/mips/cavium-octeon/octeon-irq.c
index be5d4af..844f882 100644
--- a/arch/mips/cavium-octeon/octeon-irq.c
+++ b/arch/mips/cavium-octeon/octeon-irq.c
@@ -2609,7 +2609,10 @@ static void octeon_irq_ciu3_ip2(void)
 		else
 			hw = intsn;

-		ret = handle_domain_irq(domain, hw, NULL);
+		irq_enter();
+		ret = generic_handle_domain_irq(domain, hw);
+		irq_exit();
+
 		if (ret < 0) {
 			union cvmx_ciu3_iscx_w1c isc_w1c;
 			u64 isc_w1c_addr = ciu3_addr + CIU3_ISC_W1C(intsn);