>From aa0de4edc17ef1e5e4933d927db5525f990288f5 Mon Sep 17 00:00:00 2001
From: Jacob Pan <[email protected]>
Date: Mon, 9 Nov 2009 11:24:14 -0800
Subject: [PATCH] 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: Jacob Pan <[email protected]>
---
arch/x86/include/asm/i8259.h | 13 ++++++++++++
arch/x86/kernel/i8259.c | 43 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 56 insertions(+), 0 deletions(-)
diff --git a/arch/x86/include/asm/i8259.h b/arch/x86/include/asm/i8259.h
index 58d7091..e8a3e05 100644
--- a/arch/x86/include/asm/i8259.h
+++ b/arch/x86/include/asm/i8259.h
@@ -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);
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
index df89102..b80987c 100644
--- a/arch/x86/kernel/i8259.c
+++ b/arch/x86/kernel/i8259.c
@@ -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;
--
1.5.6.5