Messages in this thread Patch in this message | | | Subject | Re: lapic-related boot crash in 4.15-rc1 | From | Dou Liyang <> | Date | Thu, 11 Jan 2018 11:10:03 +0800 |
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Hi Thomas, Meelis
At 01/11/2018 02:34 AM, Thomas Gleixner wrote: > On Wed, 10 Jan 2018, Meelis Roos wrote: >> On 3 of my test computers, boot hangs with 4.15 git kernels. So far I >> have traced it down to 4.14.0 being good and 4.15-rc1 being bad (bisect >> is slow because the computers are somwehat remote). Also because of >> trying to find when it started, I have not tries newer than rc5 >> kernels. >> >> The hang happens after Performance Events feature table has been printed >> but before APIC initialization messages normally appear ("Enabling APIC >> mode: Flat. Using 0 I/O APICs" or something like that). >> >> It happens on at least 3 distinct computers: >> * AMD Athlon with AMD 750 chipset >> * P3 1 GHz with i815 chipset >> * P4 1.7 GHz with SiS chipset >> >> They all have have "lapic" parameter because they were telling me that >> lapic has been disabled by BIOS and I re-enabled it with the parameter >> to get apic timer interrupts. This worked up until 4.14. >> >> None of the computers have IO-APICs. > > Oh. Then it possibly falls into Dou's realm. > > Dou? >
Ah, This problem looks like what Ville reported[1].
Revert the commit b371ae0d4a19 ("x86/apic: Remove init_bsp_APIC()") may make it work again.
But, I don't know the true reason.
In Linux v4.15-rc1+, apic->setup_apic_routing() has been called earlier, So, I guess kernel may hang in some early initcall fuctions. we can add "initcall_debug" option in the kernel command line for tracing initcalls as they are executed.
[1] https://marc.info/?l=linux-kernel&m=151188084018443&w=2
Thanks, dou. --------------------------->8-----------------------------------
From: Ville Syrjälä <ville.syrjala@linux.intel.com>
This reverts commit b371ae0d4a194b178817b0edfb6a7395c7aec37a.
Causes my P3 UP machine to hang at boot with "lapic".
Cc: Dou Liyang <douly.fnst@cn.fujitsu.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: yinghai@kernel.org Cc: bhe@redhat.com Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> --- arch/x86/include/asm/apic.h | 1 + arch/x86/kernel/apic/apic.c | 49 +++++++++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/irqinit.c | 3 +++ 3 files changed, 53 insertions(+)
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index a9e57f08bfa6..98722773391d 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -136,6 +136,7 @@ extern void disconnect_bsp_APIC(int virt_wire_setup); extern void disable_local_APIC(void); extern void lapic_shutdown(void); extern void sync_Arb_IDs(void); +extern void init_bsp_APIC(void); extern void apic_intr_mode_init(void); extern void setup_local_APIC(void); extern void init_apic_mappings(void); diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 6e272f3ea984..cec9aaea7f9d 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1286,6 +1286,55 @@ static int __init apic_intr_mode_select(void) return APIC_SYMMETRIC_IO; }
+/* + * An initial setup of the virtual wire mode. + */ +void __init init_bsp_APIC(void) +{ + unsigned int value; + + /* + * Don't do the setup now if we have a SMP BIOS as the + * through-I/O-APIC virtual wire mode might be active. + */ + if (smp_found_config || !boot_cpu_has(X86_FEATURE_APIC)) + return; + + /* + * Do not trust the local APIC being empty at bootup. + */ + clear_local_APIC(); + + /* + * Enable APIC. + */ + value = apic_read(APIC_SPIV); + value &= ~APIC_VECTOR_MASK; + value |= APIC_SPIV_APIC_ENABLED; + +#ifdef CONFIG_X86_32 + /* This bit is reserved on P4/Xeon and should be cleared */ + if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) && + (boot_cpu_data.x86 == 15)) + value &= ~APIC_SPIV_FOCUS_DISABLED; + else +#endif + value |= APIC_SPIV_FOCUS_DISABLED; + value |= SPURIOUS_APIC_VECTOR; + apic_write(APIC_SPIV, value); + + /* + * Set up the virtual wire mode. + */ + apic_write(APIC_LVT0, APIC_DM_EXTINT); + value = APIC_DM_NMI; + if (!lapic_is_integrated()) /* 82489DX */ + value |= APIC_LVT_LEVEL_TRIGGER; + if (apic_extnmi == APIC_EXTNMI_NONE) + value |= APIC_LVT_MASKED; + apic_write(APIC_LVT1, value); +} + /* Init the interrupt delivery mode for the BSP */ void __init apic_intr_mode_init(void) { diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c index 8da3e909e967..a539410c4ea9 100644 --- a/arch/x86/kernel/irqinit.c +++ b/arch/x86/kernel/irqinit.c @@ -61,6 +61,9 @@ void __init init_ISA_irqs(void) struct irq_chip *chip = legacy_pic->chip; int i;
+#if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC) + init_bsp_APIC(); +#endif legacy_pic->init(0);
for (i = 0; i < nr_legacy_irqs(); i++) -- > Thanks, > tglx > > >
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