x86/apic: Simplify init_bsp_APIC() usage

Since CONFIG_X86_64 selects CONFIG_X86_LOCAL_APIC, the following
condition:

  #if defined(CONFIG_X86_64) || defined(CONFIG_X86_LOCAL_APIC)

is equivalent to:

  #if defined(CONFIG_X86_LOCAL_APIC)

... and we can eliminate that #ifdef by providing an empty
init_bsp_APIC() stub in the !CONFIG_X86_LOCAL_APIC case.

Also add some comments to explain why we call init_bsp_APIC().

Signed-off-by: Dou Liyang <douly.fnst@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: mroos@linux.ee
Cc: ville.syrjala@linux.intel.com
Link: http://lkml.kernel.org/r/20180117073748.23905-1-douly.fnst@cn.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Dou Liyang 2018-01-17 15:37:48 +08:00 committed by Ingo Molnar
parent afed7d1720
commit ccf5355d05
2 changed files with 8 additions and 2 deletions

View File

@ -183,6 +183,7 @@ 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 init_bsp_APIC(void) { }
static inline void apic_intr_mode_init(void) { }
static inline void lapic_assign_system_vectors(void) { }
static inline void lapic_assign_legacy_vector(unsigned int i, bool r) { }

View File

@ -61,9 +61,14 @@ 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)
/*
* Try to set up the through-local-APIC virtual wire mode earlier.
*
* On some 32-bit UP machines, whose APIC has been disabled by BIOS
* and then got re-enabled by "lapic", it hangs at boot time without this.
*/
init_bsp_APIC();
#endif
legacy_pic->init(0);
for (i = 0; i < nr_legacy_irqs(); i++)