Commit 0902d501 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull x96 apic updates from Thomas Gleixner:
 "Updates for the x86 APIC interrupt handling and APIC timer:

   - Fix a long standing issue with spurious interrupts which was caused
     by the big vector management rework a few years ago. Robert Hodaszi
     provided finally enough debug data and an excellent initial failure
     analysis which allowed to understand the underlying issues.

     This contains a change to the core interrupt management code which
     is required to handle this correctly for the APIC/IO_APIC. The core
     changes are NOOPs for most architectures except ARM64. ARM64 is not
     impacted by the change as confirmed by Marc Zyngier.

   - Newer systems allow to disable the PIT clock for power saving
     causing panic in the timer interrupt delivery check of the IO/APIC
     when the HPET timer is not enabled either. While the clock could be
     turned on this would cause an endless whack a mole game to chase
     the proper register in each affected chipset.

     These systems provide the relevant frequencies for TSC, CPU and the
     local APIC timer via CPUID and/or MSRs, which allows to avoid the
     PIT/HPET based calibration. As the calibration code is the only
     usage of the legacy timers on modern systems and is skipped anyway
     when the frequencies are known already, there is no point in
     setting up the PIT and actually checking for the interrupt delivery
     via IO/APIC.

     To achieve this on a wide variety of platforms, the CPUID/MSR based
     frequency readout has been made more robust, which also allowed to
     remove quite some workarounds which turned out to be not longer
     required. Thanks to Daniel Drake for analysis, patches and
     verification"

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/irq: Seperate unused system vectors from spurious entry again
  x86/irq: Handle spurious interrupt after shutdown gracefully
  x86/ioapic: Implement irq_get_irqchip_state() callback
  genirq: Add optional hardware synchronization for shutdown
  genirq: Fix misleading synchronize_irq() documentation
  genirq: Delay deactivation in free_irq()
  x86/timer: Skip PIT initialization on modern chipsets
  x86/apic: Use non-atomic operations when possible
  x86/apic: Make apic_bsp_setup() static
  x86/tsc: Set LAPIC timer period to crystal clock frequency
  x86/apic: Rename 'lapic_timer_frequency' to 'lapic_timer_period'
  x86/tsc: Use CPUID.0x16 to calculate missing crystal frequency
parents 927ba67a f8a8fe61

arch/x86/entry/entry_32.S

+24 −0
Original line number Diff line number Diff line
@@ -1104,6 +1104,30 @@ ENTRY(irq_entries_start) 
    .endr

END(irq_entries_start)



#ifdef CONFIG_X86_LOCAL_APIC

	.align 8

ENTRY(spurious_entries_start)

    vector=FIRST_SYSTEM_VECTOR

    .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)

	pushl	$(~vector+0x80)			/* Note: always in signed byte range */

    vector=vector+1

	jmp	common_spurious

	.align	8

    .endr

END(spurious_entries_start)



common_spurious:

	ASM_CLAC

	addl	$-0x80, (%esp)			/* Adjust vector into the [-256, -1] range */

	SAVE_ALL switch_stacks=1

	ENCODE_FRAME_POINTER

	TRACE_IRQS_OFF

	movl	%esp, %eax

	call	smp_spurious_interrupt

	jmp	ret_from_intr

ENDPROC(common_interrupt)

#endif



/*

 * the CPU automatically disables interrupts when executing an IRQ vector,

 * so IRQ-flags tracing has to follow that:

arch/x86/entry/entry_64.S

+26 −4
Original line number Diff line number Diff line
@@ -375,6 +375,18 @@ ENTRY(irq_entries_start) 
    .endr

END(irq_entries_start)



	.align 8

ENTRY(spurious_entries_start)

    vector=FIRST_SYSTEM_VECTOR

    .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)

	UNWIND_HINT_IRET_REGS

	pushq	$(~vector+0x80)			/* Note: always in signed byte range */

	jmp	common_spurious

	.align	8

	vector=vector+1

    .endr

END(spurious_entries_start)



.macro DEBUG_ENTRY_ASSERT_IRQS_OFF

#ifdef CONFIG_DEBUG_ENTRY

	pushq %rax
@@ -573,8 +585,18 @@ _ASM_NOKPROBE(interrupt_entry) 


/*

 * The interrupt stubs push (~vector+0x80) onto the stack and

	 * then jump to common_interrupt.

 * then jump to common_spurious/interrupt.

 */

common_spurious:

	addq	$-0x80, (%rsp)			/* Adjust vector to [-256, -1] range */

	call	interrupt_entry

	UNWIND_HINT_REGS indirect=1

	call	smp_spurious_interrupt		/* rdi points to pt_regs */

	jmp	ret_from_intr

END(common_spurious)

_ASM_NOKPROBE(common_spurious)



/* common_interrupt is a hotpath. Align it */

	.p2align CONFIG_X86_L1_CACHE_SHIFT

common_interrupt:

	addq	$-0x80, (%rsp)			/* Adjust vector to [-256, -1] range */

arch/x86/include/asm/apic.h

+3 −2
Original line number Diff line number Diff line
@@ -53,7 +53,7 @@ extern unsigned int apic_verbosity; 
extern int local_apic_timer_c2_ok;



extern int disable_apic;

extern unsigned int lapic_timer_frequency;

extern unsigned int lapic_timer_period;



extern enum apic_intr_mode_id apic_intr_mode;

enum apic_intr_mode_id {
@@ -155,7 +155,6 @@ static inline int apic_force_enable(unsigned long addr) 
extern int apic_force_enable(unsigned long addr);

#endif



extern void apic_bsp_setup(bool upmode);

extern void apic_ap_setup(void);



/*
@@ -175,6 +174,7 @@ extern void lapic_assign_system_vectors(void); 
extern void lapic_assign_legacy_vector(unsigned int isairq, bool replace);

extern void lapic_online(void);

extern void lapic_offline(void);

extern bool apic_needs_pit(void);



#else /* !CONFIG_X86_LOCAL_APIC */

static inline void lapic_shutdown(void) { }
@@ -188,6 +188,7 @@ 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) { }

static inline bool apic_needs_pit(void) { return true; }

#endif /* !CONFIG_X86_LOCAL_APIC */



#ifdef CONFIG_X86_X2APIC

arch/x86/include/asm/hw_irq.h

+4 −1
Original line number Diff line number Diff line
@@ -150,8 +150,11 @@ extern char irq_entries_start[]; 
#define trace_irq_entries_start irq_entries_start

#endif



extern char spurious_entries_start[];



#define VECTOR_UNUSED		NULL

#define VECTOR_RETRIGGERED	((void *)~0UL)

#define VECTOR_SHUTDOWN		((void *)~0UL)

#define VECTOR_RETRIGGERED	((void *)~1UL)



typedef struct irq_desc* vector_irq_t[NR_VECTORS];

DECLARE_PER_CPU(vector_irq_t, vector_irq);

arch/x86/include/asm/time.h

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


extern void hpet_time_init(void);

extern void time_init(void);

extern bool pit_timer_init(void);



extern struct clock_event_device *global_clock_event;

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