Date: Wed, 1 Oct 2003 14:57:52 -0400 From: Richy Kim <rkim@sandvine.com> To: "'freebsd-scsi@freebsd.org'" <freebsd-scsi@freebsd.org> Cc: "'freebsd-hardware@freebsd.org'" <freebsd-hardware@freebsd.org> Subject: RE: SCSI, SMP, and Supermicro, problems! Message-ID: <FE045D4D9F7AED4CBFF1B3B813C8533702425628@mail.sandvine.com>
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David,
patch below basically compacts or unswizzles the pin-pin to 1:1 mapping when
the mptable is parsed, thus saving a few interrupts...
This is more so a workaround than a solution to FreeBSD's (4.x and older)
historical interrupt limits.
-r.
Index: mp_machdep.c
===================================================================
RCS file: /cvs/src/sys/i386/i386/mp_machdep.c,v
retrieving revision 1.115.2.12
retrieving revision 1.115.2.12.1000.1
diff -u -r1.115.2.12 -r1.115.2.12.1000.1
--- mp_machdep.c 28 Apr 2002 18:18:17 -0000 1.115.2.12
+++ mp_machdep.c 14 Aug 2003 15:33:01 -0000 1.115.2.12.1000.1
@@ -27,6 +27,7 @@
#include "opt_cpu.h"
#include "opt_user_ldt.h"
+#include "opt_unswizzle.h"
#ifdef SMP
#include <machine/smptests.h>
@@ -1404,6 +1405,30 @@
int_entry(int_entry_ptr entry, int intr)
{
int apic;
+#ifdef UNSWIZZLE
+ int src_pin = entry->src_bus_irq & 3;
+ int dst_pin = entry->dst_apic_int & 3;
+ int slot = (entry->src_bus_irq >> 2) & 0x1f;
+
+ if (src_pin != dst_pin) {
+ /* not 1:1 mapping, possibly a swizzled (pci) device behind
a bridge */
+
+ /* swizzle src pin based pci 1.1 spec */
+ int pin = (src_pin + slot) % 4;
+
+ if (pin == dst_pin) {
+ /* BIOS has properly swizzled/rotated pins for this
device
+ * However, we will un-swizzle the pin to get 1:1
mapping.
+ * This will save us some interrupts in cases where all
+ * slots behind the bridge use only first two pins
anyways.
+ */
+
+ printf("IOAPIC: unswizzle intpin %d",
entry->dst_apic_int);
+ entry->dst_apic_int = (entry->dst_apic_int & ~3) +
src_pin;
+ printf(" --> %d\n", entry->dst_apic_int);
+ }
+ }
+#endif
io_apic_ints[intr].int_type = entry->int_type;
io_apic_ints[intr].int_flags = entry->int_flags;
-----Original Message-----
From: Don Bowman
Sent: Wednesday, October 01, 2003 2:42 PM
To: 'David Raistrick'; Richy Kim; freebsd-scsi@freebsd.org
Cc: freebsd-hardware@freebsd.org
Subject: RE: SCSI, SMP, and Supermicro, problems!
From: David Raistrick [mailto:drais@wow.atlasta.net]
> > Since the above, I rebooted the system again...and for the
> first time I
> > have a running SMP system.
>
> ...which degraded into being hung right after I sent the last email:
>
> ahd0: Timedout SCB already complete. Interrupts may not be
> functioning.
>
> ahd0: Timedout SCB already complete. Interrupts may not be
> functioning.
>
Well, another suggestion has to do with the use of the APIC
and interrupt rotation.
I can't recall the exact details of this, we ended up adding
a 'options UNSWIZZLE' to the kernel. This was specifically
for stuff behind a bridge. The problem was that BSD only
allowed 24 interrupts, and we had run out.
--don
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