This patchset makes it possible to use the kgdb NMI infrastructure on ARM platforms.
The kgdb NMI infrastructure works by re-routing an UARTs interrupt signal from IRQ to FIQ. The UART will no longer function normally and will instead be managed by kgdb using the polled I/O functions. Any character delivered to the UART causes the kgdb handler function to be called. Each serial driver explicitly consents (or not) to this abuse by calling the appropriate registration functions.
[PATCH 1/8] arm: fiq: Allow EOI to be communicated to the intc [PATCH 2/8] irqchip: gic: Provide support for interrupt grouping Both these patches lay the ground work to allow modern ARM interrupt controllers to support FIQ correctly.
[PATCH 3/8] ARM: Move some macros from entry-armv to entry-header [PATCH 4/8] ARM: Add KGDB/KDB FIQ debugger generic code This is the heart of the patch series, allowing FIQs to be registered with KGDB and handled by KGDB.
[PATCH 5/8] serial: amba-pl011: Pass on FIQ information to KGDB. [PATCH 6/8] serial: asc: Add support for KGDB's FIQ/NMI mode Extend to UART drivers to allow the register the appropriate FIQ (implicitly promising to behave properly when their own IRQ handler is cut off).
[PATCH 7/8] ARM: VIC: Add vic_set_fiq function to select if an... [PATCH 8/8] arm: fiq: Hack FIQ routing backdoors into GIC and VIC Here we hit the serious request-for-comment section. It is not clear what the best way to get the interrupt controller to re-route an interrupt source from the IRQ signal to the FIQ signal.
Clearly the approach here is wrong but it has been enough for me to test my work so far.
Anton Vorontsov (2): ARM: Move some macros from entry-armv to entry-header ARM: Add KGDB/KDB FIQ debugger generic code
Arve Hjønnevåg (1): ARM: VIC: Add vic_set_fiq function to select if an interrupt should generate an IRQ or FIQ
Daniel Thompson (5): arm: fiq: Allow EOI to be communicated to the intc irqchip: gic: Provide support for interrupt grouping serial: amba-pl011: Pass on FIQ information to KGDB. serial: asc: Add support for KGDB's FIQ/NMI mode arm: fiq: Hack FIQ routing backdoors into GIC and VIC
arch/arm/Kconfig | 2 + arch/arm/Kconfig.debug | 18 ++++ arch/arm/boot/dts/stih416.dtsi | 2 +- arch/arm/boot/dts/vexpress-v2m-rs1.dtsi | 2 +- arch/arm/include/asm/fiq.h | 1 + arch/arm/include/asm/kgdb.h | 7 ++ arch/arm/kernel/Makefile | 1 + arch/arm/kernel/entry-armv.S | 151 +---------------------------- arch/arm/kernel/entry-header.S | 164 ++++++++++++++++++++++++++++++++ arch/arm/kernel/fiq.c | 50 ++++++++++ arch/arm/kernel/kgdb_fiq.c | 117 +++++++++++++++++++++++ arch/arm/kernel/kgdb_fiq_entry.S | 87 +++++++++++++++++ drivers/irqchip/irq-gic.c | 62 +++++++++++- drivers/irqchip/irq-vic.c | 23 +++++ drivers/tty/serial/amba-pl011.c | 18 +++- drivers/tty/serial/st-asc.c | 25 +++++ include/linux/irqchip/arm-gic.h | 3 + include/linux/irqchip/arm-vic.h | 1 + 18 files changed, 576 insertions(+), 158 deletions(-) create mode 100644 arch/arm/kernel/kgdb_fiq.c create mode 100644 arch/arm/kernel/kgdb_fiq_entry.S