Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ef354866 authored by Jacob Pan's avatar Jacob Pan Committed by H. Peter Anvin
Browse files

x86, pic: Introduce legacy_pic abstraction 



This patch makes i8259A like legacy programmable interrupt controller
code into a driver so that legacy pic functions can be selected at
runtime based on platform information, such as HW subarchitecure ID.
Default structure of legacy_pic maintains the current code path for
x86pc.

Signed-off-by: default avatarJacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D03@orsmsx508.amr.corp.intel.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent 35f720c5

arch/x86/include/asm/i8259.h

+13 −0
Original line number Diff line number Diff line
@@ -57,6 +57,19 @@ static inline void outb_pic(unsigned char value, unsigned int port) 


extern struct irq_chip i8259A_chip;



struct legacy_pic {

	int nr_legacy_irqs;

	struct irq_chip *chip;

	void (*mask_all)(void);

	void (*restore_mask)(void);

	void (*init)(int auto_eoi);

	int (*irq_pending)(unsigned int irq);

	void (*make_irq)(unsigned int irq);

};



extern struct legacy_pic *legacy_pic;

extern struct legacy_pic null_legacy_pic;



extern void mask_8259A(void);

extern void unmask_8259A(void);

arch/x86/kernel/i8259.c

+43 −0
Original line number Diff line number Diff line
@@ -358,3 +358,46 @@ void init_8259A(int auto_eoi) 


	spin_unlock_irqrestore(&i8259A_lock, flags);

}

/*

 * make i8259 a driver so that we can select pic functions at run time. the goal

 * is to make x86 binary compatible among pc compatible and non-pc compatible

 * platforms, such as x86 MID.

 */



static void __init legacy_pic_noop(void) { };

static void __init legacy_pic_uint_noop(unsigned int unused) { };

static void __init legacy_pic_int_noop(int unused) { };



static struct irq_chip dummy_pic_chip  = {

	.name = "dummy pic",

	.mask = legacy_pic_uint_noop,

	.unmask = legacy_pic_uint_noop,

	.disable = legacy_pic_uint_noop,

	.mask_ack = legacy_pic_uint_noop,

};

static int legacy_pic_irq_pending_noop(unsigned int irq)

{

	return 0;

}



struct legacy_pic null_legacy_pic = {

	.nr_legacy_irqs = 0,

	.chip = &dummy_pic_chip,

	.mask_all = legacy_pic_noop,

	.restore_mask = legacy_pic_noop,

	.init = legacy_pic_int_noop,

	.irq_pending = legacy_pic_irq_pending_noop,

	.make_irq = legacy_pic_uint_noop,

};



struct legacy_pic default_legacy_pic = {

	.nr_legacy_irqs = NR_IRQS_LEGACY,

	.chip  = &i8259A_chip,

	.mask_all  = mask_8259A,

	.restore_mask = unmask_8259A,

	.init = init_8259A,

	.irq_pending = i8259A_irq_pending,

	.make_irq = make_8259A_irq,

};



struct legacy_pic *legacy_pic = &default_legacy_pic;