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authorJacob Pan <jacob.jun.pan@intel.com>2009-11-09 20:24:14 +0100
committerH. Peter Anvin <hpa@zytor.com>2010-02-20 01:25:17 +0100
commitef3548668c02cc8c3922f4423f32b53e662811c6 (patch)
treec9f2b35d0614185bcecd31c94a564ca7e03ca53f /arch/x86/kernel
parentx86: Initialize stack canary in secondary start (diff)
downloadlinux-ef3548668c02cc8c3922f4423f32b53e662811c6.tar.xz
linux-ef3548668c02cc8c3922f4423f32b53e662811c6.zip
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 <jacob.jun.pan@intel.com> LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D03@orsmsx508.amr.corp.intel.com> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/i8259.c43
1 files changed, 43 insertions, 0 deletions
diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c
index df89102bef80..b80987ca33ea 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;