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| author | Dou Liyang <douly.fnst@cn.fujitsu.com> | 2017-09-13 17:12:45 +0800 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-09-25 15:03:14 +0200 |
| commit | 4b1669e8d1e4e6cb65b3b114fced6ca9bc39ddea (patch) | |
| tree | ea6220a25046411368f9aada3ad54a07bd23f737 | |
| parent | 0114a8e87772c4172bf7fefa4c7a9a6bbc52d2ab (diff) | |
| download | linux-4b1669e8d1e4e6cb65b3b114fced6ca9bc39ddea.tar.bz2 | |
x86/apic: Prepare for unifying the interrupt delivery modes setup
There are three places which initialize the interrupt delivery modes:
1) init_bsp_APIC() which is called early might setup the through-local-APIC
virtual wire mode on non SMP systems.
2) In an SMP-capable system, native_smp_prepare_cpus() tries to switch to
symmetric I/O model.
3) In UP system with UP_LATE_INIT=y, the local APIC and I/O APIC are set up
in smp_init().
There is no technical reason to make these initializations at random places
and run the kernel with the potentially wrong mode through the early boot
stage, but it has a problematic side effect: The late switch to symmetric
I/O mode causes dump-capture kernel to hang when the kernel command line
option 'notsc' is active.
Provide a new function to unify that three positions. Preparatory patch to
initialize an interrupt mode directly.
Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: yinghai@kernel.org
Cc: bhe@redhat.com
Link: https://lkml.kernel.org/r/1505293975-26005-3-git-send-email-douly.fnst@cn.fujitsu.com
| -rw-r--r-- | arch/x86/include/asm/apic.h | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 16 |
2 files changed, 18 insertions, 0 deletions
diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h index 5f01671c68f2..1a970f5a6e75 100644 --- a/arch/x86/include/asm/apic.h +++ b/arch/x86/include/asm/apic.h @@ -128,6 +128,7 @@ 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); void register_lapic_address(unsigned long address); @@ -170,6 +171,7 @@ static inline void disable_local_APIC(void) { } # define setup_boot_APIC_clock x86_init_noop # define setup_secondary_APIC_clock x86_init_noop static inline void lapic_update_tsc_freq(void) { } +static inline void apic_intr_mode_init(void) { } #endif /* !CONFIG_X86_LOCAL_APIC */ #ifdef CONFIG_X86_X2APIC diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index 39cb8c1ad98e..08585bcbb38f 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -1319,6 +1319,22 @@ void __init init_bsp_APIC(void) apic_write(APIC_LVT1, value); } +/* Init the interrupt delivery mode for the BSP */ +void __init apic_intr_mode_init(void) +{ + switch (apic_intr_mode_select()) { + case APIC_PIC: + pr_info("APIC: Keep in PIC mode(8259)\n"); + return; + case APIC_VIRTUAL_WIRE: + pr_info("APIC: Switch to virtual wire mode setup\n"); + return; + case APIC_SYMMETRIC_IO: + pr_info("APIC: Switch to symmectic I/O mode setup\n"); + return; + } +} + static void lapic_setup_esr(void) { unsigned int oldvalue, value, maxlvt; |