From e7ba176b47db2ed53f258a6b4fe9d9fc6fa437a9 Mon Sep 17 00:00:00 2001 From: Haavard Skinnemoen Date: Wed, 10 Oct 2007 14:58:29 +0200 Subject: [PATCH] [AVR32] NMI debugging Change the NMI handler to use the die notifier chain to signal anyone who cares. Add a simple "nmi debugger" which hooks into this chain and that may dump registers, task state, etc. when it happens. Signed-off-by: Haavard Skinnemoen --- Documentation/kernel-parameters.txt | 5 ++ arch/avr32/Kconfig | 10 ++++ arch/avr32/kernel/Makefile | 1 + arch/avr32/kernel/irq.c | 11 ++++ arch/avr32/kernel/nmi_debug.c | 82 +++++++++++++++++++++++++++++ arch/avr32/kernel/traps.c | 21 ++++++-- arch/avr32/mach-at32ap/at32ap700x.c | 1 + arch/avr32/mach-at32ap/extint.c | 39 +++++++++++--- include/asm-avr32/irq.h | 5 ++ include/asm-avr32/kdebug.h | 1 + 10 files changed, 166 insertions(+), 10 deletions(-) create mode 100644 arch/avr32/kernel/nmi_debug.c diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index c4178778e7..17fc60e324 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -34,6 +34,7 @@ parameter is applicable: ALSA ALSA sound support is enabled. APIC APIC support is enabled. APM Advanced Power Management support is enabled. + AVR32 AVR32 architecture is enabled. AX25 Appropriate AX.25 support is enabled. BLACKFIN Blackfin architecture is enabled. DRM Direct Rendering Management support is enabled. @@ -1123,6 +1124,10 @@ and is between 256 and 4096 characters. It is defined in the file of returning the full 64-bit number. The default is to return 64-bit inode numbers. + nmi_debug= [KNL,AVR32] Specify one or more actions to take + when a NMI is triggered. + Format: [state][,regs][,debounce][,die] + nmi_watchdog= [KNL,BUGS=X86-32] Debugging features for SMP kernels no387 [BUGS=X86-32] Tells the kernel to use the 387 maths diff --git a/arch/avr32/Kconfig b/arch/avr32/Kconfig index 516015b329..e34e2c9c94 100644 --- a/arch/avr32/Kconfig +++ b/arch/avr32/Kconfig @@ -170,6 +170,16 @@ config OWNERSHIP_TRACE enabling Nexus-compliant debuggers to keep track of the PID of the currently executing task. +config NMI_DEBUGGING + bool "NMI Debugging" + default n + help + Say Y here and pass the nmi_debug command-line parameter to + the kernel to turn on NMI debugging. Depending on the value + of the nmi_debug option, various pieces of information will + be dumped to the console when a Non-Maskable Interrupt + happens. + # FPU emulation goes here source "kernel/Kconfig.hz" diff --git a/arch/avr32/kernel/Makefile b/arch/avr32/kernel/Makefile index bc224a4e39..e4b6d122b0 100644 --- a/arch/avr32/kernel/Makefile +++ b/arch/avr32/kernel/Makefile @@ -12,3 +12,4 @@ obj-y += init_task.o switch_to.o cpu.o obj-$(CONFIG_MODULES) += module.o avr32_ksyms.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_STACKTRACE) += stacktrace.o +obj-$(CONFIG_NMI_DEBUGGING) += nmi_debug.o diff --git a/arch/avr32/kernel/irq.c b/arch/avr32/kernel/irq.c index 61f2de266f..a8e767d836 100644 --- a/arch/avr32/kernel/irq.c +++ b/arch/avr32/kernel/irq.c @@ -25,6 +25,17 @@ void ack_bad_irq(unsigned int irq) printk("unexpected IRQ %u\n", irq); } +/* May be overridden by platform code */ +int __weak nmi_enable(void) +{ + return -ENOSYS; +} + +void __weak nmi_disable(void) +{ + +} + #ifdef CONFIG_PROC_FS int show_interrupts(struct seq_file *p, void *v) { diff --git a/arch/avr32/kernel/nmi_debug.c b/arch/avr32/kernel/nmi_debug.c new file mode 100644 index 0000000000..3414b8566c --- /dev/null +++ b/arch/avr32/kernel/nmi_debug.c @@ -0,0 +1,82 @@ +/* + * Copyright (C) 2007 Atmel Corporation + * + * 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 +#include +#include +#include + +#include + +enum nmi_action { + NMI_SHOW_STATE = 1 << 0, + NMI_SHOW_REGS = 1 << 1, + NMI_DIE = 1 << 2, + NMI_DEBOUNCE = 1 << 3, +}; + +static unsigned long nmi_actions; + +static int nmi_debug_notify(struct notifier_block *self, + unsigned long val, void *data) +{ + struct die_args *args = data; + + if (likely(val != DIE_NMI)) + return NOTIFY_DONE; + + if (nmi_actions & NMI_SHOW_STATE) + show_state(); + if (nmi_actions & NMI_SHOW_REGS) + show_regs(args->regs); + if (nmi_actions & NMI_DEBOUNCE) + mdelay(10); + if (nmi_actions & NMI_DIE) + return NOTIFY_BAD; + + return NOTIFY_OK; +} + +static struct notifier_block nmi_debug_nb = { + .notifier_call = nmi_debug_notify, +}; + +static int __init nmi_debug_setup(char *str) +{ + char *p, *sep; + + register_die_notifier(&nmi_debug_nb); + if (nmi_enable()) { + printk(KERN_WARNING "Unable to enable NMI.\n"); + return 0; + } + + if (*str != '=') + return 0; + + for (p = str + 1; *p; p = sep + 1) { + sep = strchr(p, ','); + if (sep) + *sep = 0; + if (strcmp(p, "state") == 0) + nmi_actions |= NMI_SHOW_STATE; + else if (strcmp(p, "regs") == 0) + nmi_actions |= NMI_SHOW_REGS; + else if (strcmp(p, "debounce") == 0) + nmi_actions |= NMI_DEBOUNCE; + else if (strcmp(p, "die") == 0) + nmi_actions |= NMI_DIE; + else + printk(KERN_WARNING "NMI: Unrecognized action `%s'\n", + p); + if (!sep) + break; + } + + return 0; +} +__setup("nmi_debug", nmi_debug_setup); diff --git a/arch/avr32/kernel/traps.c b/arch/avr32/kernel/traps.c index 870c075e63..cf6f686d9b 100644 --- a/arch/avr32/kernel/traps.c +++ b/arch/avr32/kernel/traps.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -107,9 +108,23 @@ void _exception(long signr, struct pt_regs *regs, int code, asmlinkage void do_nmi(unsigned long ecr, struct pt_regs *regs) { - printk(KERN_ALERT "Got Non-Maskable Interrupt, dumping regs\n"); - show_regs_log_lvl(regs, KERN_ALERT); - show_stack_log_lvl(current, regs->sp, regs, KERN_ALERT); + int ret; + + nmi_enter(); + + ret = notify_die(DIE_NMI, "NMI", regs, 0, ecr, SIGINT); + switch (ret) { + case NOTIFY_OK: + case NOTIFY_STOP: + return; + case NOTIFY_BAD: + die("Fatal Non-Maskable Interrupt", regs, SIGINT); + default: + break; + } + + printk(KERN_ALERT "Got NMI, but nobody cared. Disabling...\n"); + nmi_disable(); } asmlinkage void do_critical_exception(unsigned long ecr, struct pt_regs *regs) diff --git a/arch/avr32/mach-at32ap/at32ap700x.c b/arch/avr32/mach-at32ap/at32ap700x.c index 9386e1f82f..14e61f05e1 100644 --- a/arch/avr32/mach-at32ap/at32ap700x.c +++ b/arch/avr32/mach-at32ap/at32ap700x.c @@ -13,6 +13,7 @@ #include #include +#include #include #include diff --git a/arch/avr32/mach-at32ap/extint.c b/arch/avr32/mach-at32ap/extint.c index f5bfd4c81f..e108e7bba8 100644 --- a/arch/avr32/mach-at32ap/extint.c +++ b/arch/avr32/mach-at32ap/extint.c @@ -26,16 +26,10 @@ #define EIC_MODE 0x0014 #define EIC_EDGE 0x0018 #define EIC_LEVEL 0x001c -#define EIC_TEST 0x0020 #define EIC_NMIC 0x0024 -/* Bitfields in TEST */ -#define EIC_TESTEN_OFFSET 31 -#define EIC_TESTEN_SIZE 1 - /* Bitfields in NMIC */ -#define EIC_EN_OFFSET 0 -#define EIC_EN_SIZE 1 +#define EIC_NMIC_ENABLE (1 << 0) /* Bit manipulation macros */ #define EIC_BIT(name) \ @@ -63,6 +57,9 @@ struct eic { unsigned int first_irq; }; +static struct eic *nmi_eic; +static bool nmi_enabled; + static void eic_ack_irq(unsigned int irq) { struct eic *eic = get_irq_chip_data(irq); @@ -174,6 +171,24 @@ static void demux_eic_irq(unsigned int irq, struct irq_desc *desc) } } +int nmi_enable(void) +{ + nmi_enabled = true; + + if (nmi_eic) + eic_writel(nmi_eic, NMIC, EIC_NMIC_ENABLE); + + return 0; +} + +void nmi_disable(void) +{ + if (nmi_eic) + eic_writel(nmi_eic, NMIC, 0); + + nmi_enabled = false; +} + static int __init eic_probe(struct platform_device *pdev) { struct eic *eic; @@ -230,6 +245,16 @@ static int __init eic_probe(struct platform_device *pdev) set_irq_chained_handler(int_irq, demux_eic_irq); set_irq_data(int_irq, eic); + if (pdev->id == 0) { + nmi_eic = eic; + if (nmi_enabled) + /* + * Someone tried to enable NMI before we were + * ready. Do it now. + */ + nmi_enable(); + } + dev_info(&pdev->dev, "External Interrupt Controller at 0x%p, IRQ %u\n", eic->regs, int_irq); diff --git a/include/asm-avr32/irq.h b/include/asm-avr32/irq.h index 83e6549d77..9315724c05 100644 --- a/include/asm-avr32/irq.h +++ b/include/asm-avr32/irq.h @@ -11,4 +11,9 @@ #define irq_canonicalize(i) (i) +#ifndef __ASSEMBLER__ +int nmi_enable(void); +void nmi_disable(void); +#endif + #endif /* __ASM_AVR32_IOCTLS_H */ diff --git a/include/asm-avr32/kdebug.h b/include/asm-avr32/kdebug.h index fd7e99046b..ca4f954236 100644 --- a/include/asm-avr32/kdebug.h +++ b/include/asm-avr32/kdebug.h @@ -5,6 +5,7 @@ enum die_val { DIE_BREAKPOINT, DIE_SSTEP, + DIE_NMI, }; #endif /* __ASM_AVR32_KDEBUG_H */ -- 2.39.5