Messages in this thread | | | From | Mark Rutland <> | Subject | [PATCH 0/8] arm64: Support FIQ controller registration | Date | Fri, 19 Feb 2021 11:38:56 +0000 |
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Hector's M1 support series [1] shows that some platforms have critical interrupts wired to FIQ, and to support these platforms we need to support handling FIQ exceptions. Other contemporary platforms don't use FIQ (since e.g. this is usually routed to EL3), and as we never expect to take an FIQ, we have the FIQ vector cause a panic.
Since the use of FIQ is a platform integration detail (which can differ across bare-metal and virtualized environments), we need be able to explicitly opt-in to handling FIQs while retaining the existing behaviour otherwise. This series adds a new set_handle_fiq() hook so that the FIQ controller can do so, and where no controller is registered the default handler will panic(). For consistency the set_handle_irq() code is made to do the same.
The first couple of patches are from Marc's irq/drop-generic_irq_multi_handler branch [2] on kernel.org, and clean up CONFIG_GENERIC_IRQ_MULTI_HANDLER usage. The next four patches move arm64 over to a local set_handle_irq() implementation, which is written to share code with a set_handle_fiq() function in the last two patches. The only functional difference here is that if an IRQ is somehow taken prior to set_handle_irq() the default handler will directly panic() rather than the vector branching to NULL.
The penultimate patch is cherry-picked from the v2 M1 series, and as per discussion there [3] will need a few additional fixups. I've included it for now as the DAIF.IF alignment is necessary for the FIQ exception handling added in the final patch.
The final patch adds the low-level FIQ exception handling and registration mechanism atop the prior rework.
I'm hoping that we can somehow queue the first 6 patches of this series as a base for the M1 support. With that we can either cherry-pick a later version of the DAIF.IF patch here, or the M1 support series can take the FIQ handling patch. I've pushed the series out to my arm64/fiq branch [4] on kernel.org, atop v5.11.
Thanks, Mark.
[1] https://http://lore.kernel.org/r/20210215121713.57687-1-marcan@marcan.st [2] https://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms.git/log/?h=irq/drop-generic_irq_multi_handler [3] https://lore.kernelo.org/r/20210215121713.57687-9-marcan@marcan.st [4] https://git.kernel.org/pub/scm/linux/kernel/git/mark/linux.git/log/?h=arm64/fiq
Hector Martin (1): arm64: Always keep DAIF.[IF] in sync
Marc Zyngier (5): ARM: ep93xx: Select GENERIC_IRQ_MULTI_HANDLER directly irqchip: Do not blindly select CONFIG_GENERIC_IRQ_MULTI_HANDLER genirq: Allow architectures to override set_handle_irq() fallback arm64: don't use GENERIC_IRQ_MULTI_HANDLER arm64: entry: factor irq triage logic into macros
Mark Rutland (2): arm64: irq: add a default handle_irq panic function arm64: irq: allow FIQs to be handled
arch/arm/Kconfig | 1 + arch/arm64/Kconfig | 1 - arch/arm64/include/asm/assembler.h | 6 +-- arch/arm64/include/asm/daifflags.h | 4 +- arch/arm64/include/asm/irq.h | 4 ++ arch/arm64/include/asm/irqflags.h | 19 ++++--- arch/arm64/kernel/entry.S | 108 ++++++++++++++++++++++--------------- arch/arm64/kernel/irq.c | 33 +++++++++++- drivers/irqchip/Kconfig | 9 ---- include/linux/irq.h | 2 + 10 files changed, 121 insertions(+), 66 deletions(-)
-- 2.11.0
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