If enabled, kernel will able to enter KGDB upon serial line activity on UART ports.
Note that even with this patch and CONFIG_KGDB_FIQ is enabled, you still need to pass kgdb_fiq.enable=1 kernel command line option, otherwise UART will behave in a normal way.
By default UART0 is used, but this can be changed via kgdb_fiq.uart_num kernel command line option.
Signed-off-by: Anton Vorontsov anton.vorontsov@linaro.org --- arch/arm/Kconfig | 1 + arch/arm/mach-versatile/Makefile | 1 + arch/arm/mach-versatile/kgdb_fiq.c | 55 ++++++++++++++++++++++++++++++++++++++ 3 files changed, 57 insertions(+) create mode 100644 arch/arm/mach-versatile/kgdb_fiq.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index bde27c1..8fea25d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -338,6 +338,7 @@ config ARCH_VERSATILE select PLAT_VERSATILE_CLCD select PLAT_VERSATILE_CLOCK select VERSATILE_FPGA_IRQ + select ARCH_MIGHT_HAVE_KGDB_FIQ help This enables support for ARM Ltd Versatile board.
diff --git a/arch/arm/mach-versatile/Makefile b/arch/arm/mach-versatile/Makefile index 81fa3fe..bfd761f 100644 --- a/arch/arm/mach-versatile/Makefile +++ b/arch/arm/mach-versatile/Makefile @@ -7,3 +7,4 @@ obj-$(CONFIG_ARCH_VERSATILE_PB) += versatile_pb.o obj-$(CONFIG_MACH_VERSATILE_AB) += versatile_ab.o obj-$(CONFIG_MACH_VERSATILE_DT) += versatile_dt.o obj-$(CONFIG_PCI) += pci.o +obj-$(CONFIG_KGDB_FIQ) += kgdb_fiq.o diff --git a/arch/arm/mach-versatile/kgdb_fiq.c b/arch/arm/mach-versatile/kgdb_fiq.c new file mode 100644 index 0000000..dd92e40 --- /dev/null +++ b/arch/arm/mach-versatile/kgdb_fiq.c @@ -0,0 +1,55 @@ +/* + * KGDB FIQ board support + * + * Copyright 2012 Linaro Ltd. + * Anton Vorontsov anton.vorontsov@linaro.org + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published + * by the Free Software Foundation. + */ + +#include <linux/module.h> +#include <linux/init.h> +#include <linux/io.h> +#include <linux/kgdb.h> +#include <mach/hardware.h> +#include <mach/platform.h> +#include <asm/hardware/vic.h> + +static void *kgdb_irq_base; + +static int kgdb_irq; +module_param_named(uart_num, kgdb_irq, int, 0600); +MODULE_PARM_DESC(uart_num, "UART<number> port to use for KGDB FIQ"); + +static void kgdb_fiq_select(bool on) +{ + void __iomem *sel = kgdb_irq_base + VIC_INT_SELECT; + u32 msk = 1 << kgdb_irq; + u32 val; + + pr_debug("rerouting VIC vector %d to %s\n", kgdb_irq, + on ? "FIQ" : "IRQ"); + + val = readl(sel); + val &= ~msk; + if (on) + val |= msk; + writel(val, sel); +} + +static bool kgdb_is_fiq_rised(void) +{ + return readl(kgdb_irq_base + VIC_FIQ_STATUS) & (1 << kgdb_irq); +} + +static int __init kgdb_fiq_init(void) +{ + kgdb_irq_base = __io_address(VERSATILE_VIC_BASE); + kgdb_irq += INT_UARTINT0; + WARN_ON(kgdb_irq > INT_UARTINT2); + + return kgdb_register_fiq(kgdb_fiq_select, kgdb_is_fiq_rised); +} +console_initcall(kgdb_fiq_init);