Attachment 597855 Details for Bug 771624 – Patch from Gerd Hoffmann

[patch] Patch from Gerd Hoffmann

0001-isa-refine-irq-reservations.patch (text/plain), 2.30 KB, created by Neal Kim on 2012-07-12 17:06:20 UTC

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Creator: Neal Kim

Created: 2012-07-12 17:06:20 UTC

Size: 2.30 KB

patch

obsolete

>From 7d5d53e8a23544ac6413487a8ecdd43537ade9f3 Mon Sep 17 00:00:00 2001
>From: Gerd Hoffmann <kraxel@redhat.com>
>Date: Fri, 11 Sep 2009 13:43:46 +0200
>Subject: [PATCH] isa: refine irq reservations
>
>There are a few cases where IRQ sharing on the ISA bus is used and
>possible.  In general only devices of the same kind can do that.
>A few use cases:
>
>  * serial lines 1+3 share irq 4
>  * serial lines 2+4 share irq 3
>  * parallel ports share irq 7
>  * ppc/prep: ide ports share irq 13
>
>This patch refines the irq reservation mechanism for the isa bus to
>handle those cases.  It keeps track of the driver which owns the IRQ in
>question and allows irq sharing for devices handled by the same driver.
>
>Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
>---
> hw/isa-bus.c |   16 +++++++++++++---
> 1 files changed, 13 insertions(+), 3 deletions(-)
>
>diff --git a/hw/isa-bus.c b/hw/isa-bus.c
>index 4d489d2..bd2f69c 100644
>--- a/hw/isa-bus.c
>+++ b/hw/isa-bus.c
>@@ -26,6 +26,7 @@ struct ISABus {
>     BusState qbus;
>     qemu_irq *irqs;
>     uint32_t assigned;
>+    DeviceInfo *irq_owner[16];
> };
> static ISABus *isabus;
> 
>@@ -71,7 +72,9 @@ qemu_irq isa_reserve_irq(int isairq)
>         exit(1);
>     }
>     if (isabus->assigned & (1 << isairq)) {
>-        fprintf(stderr, "isa irq %d already assigned\n", isairq);
>+        DeviceInfo *owner = isabus->irq_owner[isairq];
>+        fprintf(stderr, "isa irq %d already assigned (%s)\n",
>+                isairq, owner ? owner->name : "unknown");
>         exit(1);
>     }
>     isabus->assigned |= (1 << isairq);
>@@ -82,10 +85,17 @@ void isa_init_irq(ISADevice *dev, qemu_irq *p, int isairq)
> {
>     assert(dev->nirqs < ARRAY_SIZE(dev->isairq));
>     if (isabus->assigned & (1 << isairq)) {
>-        fprintf(stderr, "isa irq %d already assigned\n", isairq);
>-        exit(1);
>+        DeviceInfo *owner = isabus->irq_owner[isairq];
>+        if (owner == dev->qdev.info) {
>+            /* irq sharing is ok in case the same driver handles both */;
>+        } else {
>+            fprintf(stderr, "isa irq %d already assigned (%s)\n",
>+                    isairq, owner ? owner->name : "unknown");
>+            exit(1);
>+        }
>     }
>     isabus->assigned |= (1 << isairq);
>+    isabus->irq_owner[isairq] = dev->qdev.info;
>     dev->isairq[dev->nirqs] = isairq;
>     *p = isabus->irqs[isairq];
>     dev->nirqs++;
>-- 
>1.6.6.1
>

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Attachments on bug 771624: 597855