From: Bernhard Beschow <shentey@gmail.com>
To: qemu-devel@nongnu.org
Cc: Bernhard Beschow <shentey@gmail.com>
Subject: [PATCH 0/3] malta: Move PCI interrupt handling from gt64xxx to piix4
Date: Wed, 12 Jan 2022 22:36:25 +0100 [thread overview]
Message-ID: <20220112213629.9126-1-shentey@gmail.com> (raw)
Hi,
first-time contributor here. Inspired by an article in LWN [1] I figured I'd
get my hands dirty with QEMU development. According to the article my goal is
to eliminate some "accidental complexity".
While studying the code I noticed some (accidental?) differences between piix3
and piix4 where the PCI interrupts are handled. Moreover, I noticed presence of
global variables in piix4 which probably constitute a limitation of QOM's idea
of configuration-driven machine creation. By applying piix3 concepts, i.e.
moving the interrupt handling from gt64xxx to piix4, it's possible to both
eliminate the differences and resolve the global variables.
The patch series is structured as follows: Patch 1 eliminates the differences,
patch 3 resolves the global variables. Patch 2 is a preparation for patch 3.
Some of my further comments regarding the patches are:
Patch 1:
* pci_slot_get_pirq() looks quite malta-specific. Neither gt64xxx nor piix4
seem to be the perfect fit. So I moved it to piix4, analogous to piix3.
* The i8259 property moved from MaltaState to PIIX4State looks quite redundant
to the isa property. Could isa be used instead, eliminating i8259?
Patch 2:
* Besides piix4, there were four further cases where the PIC array was passed
as the opaque parameter to the pci_map_irq_fn's. AFAICS in all other cases
the DeviceState is passed instead. With this patch, consistency is
esablished.
* Passing PIIX4State to piix4_set_irq() paves the way for eliminating all
global variables left in piix4.c (see patch 3).
Comments welcome.
Cheers
Bernhard
[1] https://lwn.net/Articles/872321/
Bernhard Beschow (3):
malta: Move PCI interrupt handling from gt64xxx to piix4
pci: Always pass own DeviceState to pci_map_irq_fn's
isa/piix4: Resolve global variables
hw/isa/piix4.c | 62 ++++++++++++++++++++++++++++++++---
hw/mips/gt64xxx_pci.c | 62 +++--------------------------------
hw/mips/malta.c | 6 +---
hw/pci-host/sh_pci.c | 6 ++--
hw/pci-host/versatile.c | 6 ++--
hw/ppc/ppc440_pcix.c | 6 ++--
hw/ppc/ppc4xx_pci.c | 6 ++--
include/hw/mips/mips.h | 2 +-
include/hw/southbridge/piix.h | 2 --
9 files changed, 77 insertions(+), 81 deletions(-)
--
2.34.1
next reply other threads:[~2022-01-12 21:58 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-12 21:36 Bernhard Beschow [this message]
2022-01-12 21:36 ` [PATCH 1/3] malta: Move PCI interrupt handling from gt64xxx to piix4 Bernhard Beschow
2022-01-30 22:34 ` Philippe Mathieu-Daudé via
2022-01-12 21:36 ` [PATCH 2/3] pci: Always pass own DeviceState to pci_map_irq_fn's Bernhard Beschow
2022-01-14 13:29 ` Peter Maydell
2022-01-30 22:36 ` Philippe Mathieu-Daudé via
2022-01-12 21:36 ` [PATCH 3/3] isa/piix4: Resolve global variables Bernhard Beschow
2022-01-14 13:36 ` Peter Maydell
2022-01-30 22:53 ` Philippe Mathieu-Daudé via
2022-02-09 23:16 ` BB
2022-02-10 7:18 ` Michael S. Tsirkin
2022-01-30 22:39 ` Philippe Mathieu-Daudé via
2022-01-13 9:24 ` [PATCH 0/3] malta: Move PCI interrupt handling from gt64xxx to piix4 Philippe Mathieu-Daudé
2022-01-13 11:22 ` Bernhard Beschow
2022-01-13 11:53 ` Philippe Mathieu-Daudé
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20220112213629.9126-1-shentey@gmail.com \
--to=shentey@gmail.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.