# HG changeset patch
# User Jimi Xenidis <[EMAIL PROTECTED]>
# Node ID c8d1f32fd7deebb9c15e5dc4ec3bcbd3678d9488
# Parent 05367b79152a01edbcc3a834c1f6d5328635435b
[XEN][POWERPC] Make Linux bail out of IPI vector reset
Xen/PPC currently shares the mpic with dom0 Linux. In order for
interprocessor interrupts to work, we cannot allow Linux to reset the
mpic (a patch for the latter was already merged) nor to reset the IPI
vectors and change their priority.
This patch introduces a feature flag, rather than trying to code a new
function called xen_mpic_init and duplicating all the associated
machinery it pulls in. I tried the first approach, and it results in a
lot of code duplication, which is a worse maintenence burden than this,
I believe. Jimi may not like this approach, but I believe it is the
best solution until we completely virtualize the PIC at some point in
the future.
Signed-off-by: Amos Waterland <[EMAIL PROTECTED]>
Signed-off-by: Jimi Xenidis <[EMAIL PROTECTED]>
---
arch/powerpc/platforms/xen/evtchn.c | 1 +
arch/powerpc/sysdev/mpic.c | 4 ++++
include/asm-powerpc/mpic.h | 2 ++
3 files changed, 7 insertions(+)
diff -r 05367b79152a -r c8d1f32fd7de arch/powerpc/platforms/xen/evtchn.c
--- a/arch/powerpc/platforms/xen/evtchn.c Tue Nov 21 09:35:16 2006 -0500
+++ b/arch/powerpc/platforms/xen/evtchn.c Wed Nov 22 14:51:54 2006 -0500
@@ -101,6 +101,7 @@ static __init struct mpic *xen_share_map
mpic = mpic_alloc(opic_addr,
MPIC_PRIMARY | MPIC_BIG_ENDIAN |
+ MPIC_SKIP_IPI_INIT |
MPIC_BROKEN_U3 /* | MPIC_WANTS_RESET */,
0, 0, 128, 128, senses, 128, "Xen-U3-MPIC");
BUG_ON(mpic == NULL);
diff -r 05367b79152a -r c8d1f32fd7de arch/powerpc/sysdev/mpic.c
--- a/arch/powerpc/sysdev/mpic.c Tue Nov 21 09:35:16 2006 -0500
+++ b/arch/powerpc/sysdev/mpic.c Wed Nov 22 14:51:54 2006 -0500
@@ -741,6 +741,9 @@ void __init mpic_init(struct mpic *mpic)
(MPIC_VEC_TIMER_0 + i));
}
+ if (mpic->flags & MPIC_SKIP_IPI_INIT)
+ goto ipi_bailout;
+
/* Initialize IPIs to our reserved vectors and mark them disabled for
now */
mpic_test_broken_ipi(mpic);
for (i = 0; i < 4; i++) {
@@ -756,6 +759,7 @@ void __init mpic_init(struct mpic *mpic)
#endif /* CONFIG_SMP */
}
+ipi_bailout:
/* Initialize interrupt sources */
if (mpic->irq_count == 0)
mpic->irq_count = mpic->num_sources;
diff -r 05367b79152a -r c8d1f32fd7de include/asm-powerpc/mpic.h
--- a/include/asm-powerpc/mpic.h Tue Nov 21 09:35:16 2006 -0500
+++ b/include/asm-powerpc/mpic.h Wed Nov 22 14:51:54 2006 -0500
@@ -190,6 +190,8 @@ struct mpic
#define MPIC_BROKEN_IPI 0x00000008
/* MPIC wants a reset */
#define MPIC_WANTS_RESET 0x00000010
+/* Skip reset of IPI vectors during init */
+#define MPIC_SKIP_IPI_INIT 0x00000020
/* Allocate the controller structure and setup the linux irq descs
* for the range if interrupts passed in. No HW initialization is
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