Commit fa5e5c40 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/entry: Use idtentry for interrupts 



Replace the extra interrupt handling code and reuse the existing idtentry
machinery. This moves the irq stack switching on 64-bit from ASM to C code;
32-bit already does the stack switching in C.

This requires to remove HAVE_IRQ_EXIT_ON_IRQ_STACK as the stack switch is
not longer in the low level entry code.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Acked-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lore.kernel.org/r/20200521202119.078690991@linutronix.de
parent 0bf7c314

arch/x86/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -181,7 +181,6 @@ config X86 
	select HAVE_HW_BREAKPOINT

	select HAVE_IDE

	select HAVE_IOREMAP_PROT

	select HAVE_IRQ_EXIT_ON_IRQ_STACK	if X86_64

	select HAVE_IRQ_TIME_ACCOUNTING

	select HAVE_KERNEL_BZIP2

	select HAVE_KERNEL_GZIP

arch/x86/entry/entry_32.S

+0 −31
Original line number Diff line number Diff line
@@ -1229,37 +1229,6 @@ SYM_FUNC_END(entry_INT80_32) 
#endif

.endm



#ifdef CONFIG_X86_LOCAL_APIC

SYM_CODE_START_LOCAL(common_spurious)

	ASM_CLAC

	SAVE_ALL switch_stacks=1

	ENCODE_FRAME_POINTER

	TRACE_IRQS_OFF

	movl	%esp, %eax

	movl	PT_ORIG_EAX(%esp), %edx		/* get the vector from stack */

	movl	$-1, PT_ORIG_EAX(%esp)		/* no syscall to restart */

	call	smp_spurious_interrupt

	jmp	ret_from_intr

SYM_CODE_END(common_spurious)

#endif



/*

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

 * so IRQ-flags tracing has to follow that:

 */

	.p2align CONFIG_X86_L1_CACHE_SHIFT

SYM_CODE_START_LOCAL(common_interrupt)

	ASM_CLAC

	SAVE_ALL switch_stacks=1

	ENCODE_FRAME_POINTER

	TRACE_IRQS_OFF

	movl	%esp, %eax

	movl	PT_ORIG_EAX(%esp), %edx		/* get the vector from stack */

	movl	$-1, PT_ORIG_EAX(%esp)		/* no syscall to restart */

	call	do_IRQ

	jmp	ret_from_intr

SYM_CODE_END(common_interrupt)



#define BUILD_INTERRUPT3(name, nr, fn)			\

SYM_FUNC_START(name)					\

	ASM_CLAC;					\

arch/x86/entry/entry_64.S

+3 −28
Original line number Diff line number Diff line
@@ -737,32 +737,7 @@ SYM_CODE_START(interrupt_entry) 
SYM_CODE_END(interrupt_entry)

_ASM_NOKPROBE(interrupt_entry)





/* Interrupt entry/exit. */



/*

 * The interrupt stubs push vector onto the stack and

 * then jump to common_spurious/interrupt.

 */

SYM_CODE_START_LOCAL(common_spurious)

	call	interrupt_entry

	UNWIND_HINT_REGS indirect=1

	movq	ORIG_RAX(%rdi), %rsi		/* get vector from stack */

	movq	$-1, ORIG_RAX(%rdi)		/* no syscall to restart */

	call	smp_spurious_interrupt		/* rdi points to pt_regs */

	jmp	ret_from_intr

SYM_CODE_END(common_spurious)

_ASM_NOKPROBE(common_spurious)



/* common_interrupt is a hotpath. Align it */

	.p2align CONFIG_X86_L1_CACHE_SHIFT

SYM_CODE_START_LOCAL(common_interrupt)

	call	interrupt_entry

	UNWIND_HINT_REGS indirect=1

	movq	ORIG_RAX(%rdi), %rsi		/* get vector from stack */

	movq	$-1, ORIG_RAX(%rdi)		/* no syscall to restart */

	call	do_IRQ				/* rdi points to pt_regs */

	/* 0(%rsp): old RSP */

SYM_CODE_START_LOCAL(common_interrupt_return)

ret_from_intr:

	DISABLE_INTERRUPTS(CLBR_ANY)

	TRACE_IRQS_OFF
@@ -945,8 +920,8 @@ native_irq_return_ldt: 
	 */

	jmp	native_irq_return_iret

#endif

SYM_CODE_END(common_interrupt)

_ASM_NOKPROBE(common_interrupt)

SYM_CODE_END(common_interrupt_return)

_ASM_NOKPROBE(common_interrupt_return)



/*

 * APIC interrupts.

arch/x86/include/asm/hw_irq.h

+0 −1
Original line number Diff line number Diff line
@@ -38,7 +38,6 @@ extern asmlinkage void error_interrupt(void); 
extern asmlinkage void irq_work_interrupt(void);

extern asmlinkage void uv_bau_message_intr1(void);



extern asmlinkage void spurious_interrupt(void);

extern asmlinkage void spurious_apic_interrupt(void);

extern asmlinkage void thermal_interrupt(void);

extern asmlinkage void reschedule_interrupt(void);

arch/x86/include/asm/idtentry.h

+8 −2
Original line number Diff line number Diff line
@@ -417,7 +417,7 @@ SYM_CODE_START(irq_entries_start) 
    .rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)

	UNWIND_HINT_IRET_REGS

	.byte	0x6a, vector

	jmp	common_interrupt

	jmp	asm_common_interrupt

	nop

	/* Ensure that the above is 8 bytes max */

	. = pos + 8
@@ -434,7 +434,7 @@ SYM_CODE_START(spurious_entries_start) 
    .rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)

	UNWIND_HINT_IRET_REGS

	.byte	0x6a, vector

	jmp	common_spurious

	jmp	asm_spurious_interrupt

	nop

	/* Ensure that the above is 8 bytes max */

	. = pos + 8
@@ -506,6 +506,12 @@ DECLARE_IDTENTRY_DF(X86_TRAP_DF, exc_double_fault); 
DECLARE_IDTENTRY_XENCB(X86_TRAP_OTHER,	exc_xen_hypervisor_callback);

#endif



/* Device interrupts common/spurious */

DECLARE_IDTENTRY_IRQ(X86_TRAP_OTHER,	common_interrupt);

#ifdef CONFIG_X86_LOCAL_APIC

DECLARE_IDTENTRY_IRQ(X86_TRAP_OTHER,	spurious_interrupt);

#endif



#undef X86_TRAP_OTHER



#endif

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