From 2b398bd9f8f73be706b41adcbb240ce95793049a Mon Sep 17 00:00:00 2001 From: Youquan Song Date: Thu, 14 Apr 2011 14:36:08 +0800 Subject: [PATCH] x86, apic: Print verbose error interrupt reason on apic=debug End users worry about the error interrupt printout we generate currently: pr_debug("APIC error on CPU%d: %02x(%02x)\n", smp_processor_id(), v , v1); ... and would like to know the reason why error interrupts are generated. This patch prints out more detailed debug information. Another practical problem is that dynamic debug is not initialized yet when the APIC initializes, so the pr_debug() will not output the error interrupt debug information on bootup. In this patch, we use apic_printk(APIC_DEBUG, ...), so the apic=debug boot option will print verbose error interupts during bootup. Signed-off-by: Youquan Song Cc: Joe Perches Cc: hpa@linux.intel.com Cc: suresh.b.siddha@intel.com Cc: yong.y.wang@linux.intel.com Cc: jbaron@redhat.com Cc: trenn@suse.de Cc: kent.liu@intel.com Cc: chaohong.guo@intel.com Link: http://lkml.kernel.org/r/1302762968-24380-2-git-send-email-youquan.song@intel.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/apic/apic.c | 41 ++++++++++++++++++++++++++--------------- 1 file changed, 26 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index fabf01eff77..ae147126b7b 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1812,30 +1812,41 @@ void smp_spurious_interrupt(struct pt_regs *regs) */ void smp_error_interrupt(struct pt_regs *regs) { - u32 v, v1; + u32 v0, v1; + u32 i = 0; + static const char * const error_interrupt_reason[] = { + "Send CS error", /* APIC Error Bit 0 */ + "Receive CS error", /* APIC Error Bit 1 */ + "Send accept error", /* APIC Error Bit 2 */ + "Receive accept error", /* APIC Error Bit 3 */ + "Redirectable IPI", /* APIC Error Bit 4 */ + "Send illegal vector", /* APIC Error Bit 5 */ + "Received illegal vector", /* APIC Error Bit 6 */ + "Illegal register address", /* APIC Error Bit 7 */ + }; exit_idle(); irq_enter(); /* First tickle the hardware, only then report what went on. -- REW */ - v = apic_read(APIC_ESR); + v0 = apic_read(APIC_ESR); apic_write(APIC_ESR, 0); v1 = apic_read(APIC_ESR); ack_APIC_irq(); atomic_inc(&irq_err_count); - /* - * Here is what the APIC error bits mean: - * 0: Send CS error - * 1: Receive CS error - * 2: Send accept error - * 3: Receive accept error - * 4: Reserved - * 5: Send illegal vector - * 6: Received illegal vector - * 7: Illegal register address - */ - pr_debug("APIC error on CPU%d: %02x(%02x)\n", - smp_processor_id(), v , v1); + apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)", + smp_processor_id(), v0 , v1); + + v1 = v1 & 0xff; + while (v1) { + if (v1 & 0x1) + apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]); + i++; + v1 >>= 1; + }; + + apic_printk(APIC_DEBUG, KERN_CONT "\n"); + irq_exit(); } -- 2.11.4.GIT