This patchset makes it possible to use kgdb's NMI infrastructure on ARM platforms.
The patches are seperated into three distinct groups:
1. arm specific changes; these provide multi-platform support for FIQ (including raising an IPI using FIQ to ensure effective SMP support) and extend ARM KGDB support to use the features provided.
2. irqchip changes; updates to the gic and vic drivers to provide support for routing certain interrupt sources to FIQ.
3. serial changes; driver support to allow the UART interrupt to be routed to FIQ. The already mainlined kgdb NMI infrastructure (mostly found in drivers/tty/serial/kgdb_nmi.c) will re-route the kgdb console UART's interrupt signal from IRQ to FIQ. Naturally 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.
Tested on qemu (versatile), STiH416 (B2020 board) and Freescale i.MX6 quad (wandboard).
Changes since v9:
- Split PL011 code movement into a seperate patch (Peter Hurley) - Use container_of() to convert pointers to uart_amba_port (Peter Hurley) - Clean up redundant code from pl011_poll_init (Peter Hurley) - Call do_unexp_fiq() if we receive a FIQ and CONFIG_FIQ is not set. - Ensure irq-gic.c does not call FIQ functions unless CONFIG_FIQ is set. - Introduced patch to avoid ttyNMI0 being enabled by default (replaces architecture dependant enable/disable logic). - Fixed bug in kgdb_fiq_enable_nmi() that causes SysRq-g (non-NMI debugging) to wedge the debugger.
Changes since v8:
- Significant rework to separate the FIQ exception handler from kgdb. This allows other features typically implemented using NMI on x86 to reuse the same exception handling code (Russell King) - Reunited arch/arm and driver code into a single patch series again. - Added support for raising IPIs using FIQ (makes kgdb quiesce must more robust). - Introduced a workaround for GICv1 devices to avoid FIQs being spuriously handled as IRQs.
Changes since v7:
- Introduced ack_fiq() to complement eoi_fiq(). Without this it is not possible to meet the GIC specification (previous versions worked when tested but are unpredictable according to the specification). ack_fiq() also makes is possible for drivers for devices with multiple interrupt lines to discover the interrupt source correctly.
Changes since v6:
- Corrected off-by-one comparison in has_fiq() (Nicolas Pitre) - Rewrote the FIQ stack initialization (Nicolas Pitre). This fixes a serious data corruption bug due to bad stack mismanagement. - Introduced __fiq_abt to ensure lr_abt and spsr_abt are saved and restored if we fast-interrupt an abort (Russell King). - Significantly improved the commenting of the exception handlers. - Added a call to trace_hardirqs_on() if we clear the I bit as we exit the exception handler.
Changes since v5:
- Separated anything not strictly impacting arch/arm. - Fixed a spurious add/remove of code within the series (there was broken code in intermediate patches)
For previous changes see: http://thread.gmane.org/gmane.linux.ports.arm.kernel/333901
Daniel Thompson (18): arm: fiq: Add callbacks to manage FIQ routings arm: fiq: Allow ACK and EOI to be passed to the intc arm: fiq: Replace default FIQ handler arm: smp: Introduce a special IPI signalled using FIQ arm: KGDB/KDB FIQ support irqchip: gic: Provide support for interrupt grouping irqchip: gic: Add support for FIQ management irqchip: gic: Remove spin locks from eoi_irq irqchip: gic: Add support for IPI FIQ irqchip: gic: Group 0 workaround. irqchip: vic: Add support for FIQ management serial: kgdb_nmi: No CON_ENABLED by default serial: amba-pl011: Use container_of() to get uart_amba_port serial: amba-pl011: Move pl011_hwinit() serial: amba-pl011: Pass FIQ information to KGDB. serial: asc: Add support for KGDB's FIQ/NMI mode serial: asc: Adopt readl_/writel_relaxed() serial: imx: Add support for KGDB's FIQ/NMI mode
Dirk Behme (1): serial: imx: clean up imx_poll_get_char()
arch/arm/Kconfig | 2 + arch/arm/Kconfig.debug | 19 +++ arch/arm/include/asm/fiq.h | 18 +++ arch/arm/include/asm/hardirq.h | 2 +- arch/arm/include/asm/kgdb.h | 4 + arch/arm/include/asm/smp.h | 7 + arch/arm/kernel/entry-armv.S | 129 +++++++++++++++-- arch/arm/kernel/fiq.c | 139 +++++++++++++++++- arch/arm/kernel/kgdb.c | 117 ++++++++++++++- arch/arm/kernel/setup.c | 8 +- arch/arm/kernel/smp.c | 15 ++ arch/arm/mach-versatile/core.c | 2 +- drivers/irqchip/irq-gic.c | 309 +++++++++++++++++++++++++++++++++++++--- drivers/irqchip/irq-vic.c | 92 +++++++++--- drivers/tty/serial/Kconfig | 2 +- drivers/tty/serial/amba-pl011.c | 143 +++++++++++-------- drivers/tty/serial/imx.c | 88 +++++++----- drivers/tty/serial/kgdb_nmi.c | 5 +- drivers/tty/serial/st-asc.c | 27 +++- include/linux/irqchip/arm-vic.h | 6 +- 20 files changed, 977 insertions(+), 157 deletions(-)
-- 1.9.3