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Commit 3318e974 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
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x86/idt: Prepare for table based init 



The IDT setup code is handled in several places. All of them use variants
of set_intr_gate() inlines. This can be done with a table based
initialization, which allows to reduce the inline zoo and puts all IDT
related code and information into a single place.

Add the infrastructure.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.849877032@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 87e81786

arch/x86/kernel/idt.c

+67 −0
Original line number Diff line number Diff line
@@ -5,8 +5,49 @@ 
 */

#include <linux/interrupt.h>



#include <asm/traps.h>

#include <asm/proto.h>

#include <asm/desc.h>



struct idt_data {

	unsigned int	vector;

	unsigned int	segment;

	struct idt_bits	bits;

	const void	*addr;

};



#define DPL0		0x0

#define DPL3		0x3



#define DEFAULT_STACK	0



#define G(_vector, _addr, _ist, _type, _dpl, _segment)	\

	{						\

		.vector		= _vector,		\

		.bits.ist	= _ist,			\

		.bits.type	= _type,		\

		.bits.dpl	= _dpl,			\

		.bits.p		= 1,			\

		.addr		= _addr,		\

		.segment	= _segment,		\

	}



/* Interrupt gate */

#define INTG(_vector, _addr)				\

	G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL0, __KERNEL_CS)



/* System interrupt gate */

#define SYSG(_vector, _addr)				\

	G(_vector, _addr, DEFAULT_STACK, GATE_INTERRUPT, DPL3, __KERNEL_CS)



/* Interrupt gate with interrupt stack */

#define ISTG(_vector, _addr, _ist)			\

	G(_vector, _addr, _ist, GATE_INTERRUPT, DPL0, __KERNEL_CS)



/* Task gate */

#define TSKG(_vector, _gdt)				\

	G(_vector, NULL, DEFAULT_STACK, GATE_TASK, DPL0, _gdt << 3)



/* Must be page-aligned because the real IDT is used in a fixmap. */

gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;
@@ -25,6 +66,32 @@ const struct desc_ptr debug_idt_descr = { 
};

#endif



static inline void idt_init_desc(gate_desc *gate, const struct idt_data *d)

{

	unsigned long addr = (unsigned long) d->addr;



	gate->offset_low	= (u16) addr;

	gate->segment		= (u16) d->segment;

	gate->bits		= d->bits;

	gate->offset_middle	= (u16) (addr >> 16);

#ifdef CONFIG_X86_64

	gate->offset_high	= (u32) (addr >> 32);

	gate->reserved		= 0;

#endif

}



static __init void

idt_setup_from_table(gate_desc *idt, const struct idt_data *t, int size)

{

	gate_desc desc;



	for (; size > 0; t++, size--) {

		idt_init_desc(&desc, t);

		set_bit(t->vector, used_vectors);

		write_idt_entry(idt, t->vector, &desc);

	}

}



/**

 * idt_setup_early_handler - Initializes the idt table with early handlers

 */