pc, pc64, xen: rewrite interrupt handling code

This implements proper intrdisable() support for all
interrupt controllers.

For enable, (*arch->intrassign)(Vctl*) fills in the
Vctl.enable and Vctl.disable pointers with the
appropriate routines and returns the assigned
vector number.

Once the Vctl struct has been linked to its vector
chain, Vctl.enable(Vctl*, shared) gets called with a
flag if the vector has been already enabled (shared).

This order is important here as enabling the interrupt
on the controller before we have linked the chain can
cause spurious interrupts, expecially on mp system
where the interrupt can target a different cpu than
the caller of intrenable().

The intrdisable() case is the other way around.
We first disable the interrupt on the controller
and after that unlink the Vctl from the chain.
On a multiprocessor, the xfree() of the Vctl struct
is delayed to avoid freeing it while it is still
in use by another cpu.

The xen port now also uses pc/irq.c which has been
made generic enougth to handle xen's irq scheme.
Also, archgeneric is now a separate file to avoid
pulling in dependencies from the 8259 interrupt
controller code.

1 files changed, 4 insertions, 20 deletions

diff --git a/sys/src/9/xen/archxen.c b/sys/src/9/xen/archxen.c
index 50bf70f19..c4f1b5607 100644
--- a/sys/src/9/xen/archxen.c
+++ b/sys/src/9/xen/archxen.c
@@ -52,9 +52,7 @@ shutdown(void)
 	HYPERVISOR_shutdown(1);
 }
 
-int xenintrenable(Vctl *v);
-int xenintrvecno(int irq);
-int xenintrdisable(int irq);
+int xenintrassign(Vctl *v);
 void	xentimerenable(void);
 uvlong	xentimerread(uvlong*);
 void	xentimerset(uvlong);
@@ -64,16 +62,14 @@ PCArch archxen = {
 .ident=		identify,
 .reset=		shutdown,
 .intrinit=	intrinit,
-.intrenable=	xenintrenable,
-.intrvecno=	xenintrvecno,
-.intrdisable=	xenintrdisable,
+.intrassign=	xenintrassign,
 .clockenable=	xentimerenable,
 .fastclock=	xentimerread,
 .timerset=	xentimerset,
 };
 
 /*
- * Placeholders to satisfy external references in generic devarch.c
+ * Placeholders to satisfy external references in devarch.c
  */
 ulong	getcr4(void)	{ return 0; }
 void	putcr4(ulong)	{}
@@ -83,19 +79,7 @@ ulong	inl(int)	{ return 0; }
 void	outb(int, int)	{}
 void	outs(int, ushort)	{}
 void	outl(int, ulong)	{}
-void	i8042reset(void)	{}
-void	i8253enable(void)	{}
-void	i8253init(void)	{}
-void	i8253link(void)	{}
-uvlong	i8253read(uvlong*)	{ return 0; }
-void	i8253timerset(uvlong)	{}
-int	i8259disable(int)	{ return 0; }
-int	i8259enable(Vctl*)	{ return 0; }
-void	i8259init(void)	{}
-int	i8259isr(int)	{ return 0; }
-void	i8259on(void)	{}
-void	i8259off(void)	{}
-int	i8259vecno(int)	{ return 0; }
+
 int	mtrrprint(char*, long) { return 0; }
 char*	mtrr(uvlong, uvlong, char *) { return nil; }
 void	mtrrsync(void) {}