From: Arnd Bergmann <arnd@arndb.de>
To: Rob Herring <robh@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>,
Bjorn Helgaas <bhelgaas@google.com>,
"Maciej W. Rozycki" <macro@orcam.me.uk>,
Stafford Horne <shorne@gmail.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Guo Ren <guoren@kernel.org>,
Paul Walmsley <paul.walmsley@sifive.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Richard Weinberger <richard@nod.at>,
Anton Ivanov <anton.ivanov@cambridgegreys.com>,
Johannes Berg <johannes@sipsolutions.net>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
linux-csky@vger.kernel.org,
linux-riscv <linux-riscv@lists.infradead.org>,
linux-um <linux-um@lists.infradead.org>,
PCI <linux-pci@vger.kernel.org>,
"open list:GENERIC INCLUDE/ASM HEADER FILES"
<linux-arch@vger.kernel.org>
Subject: Re: [PATCH v3 2/2] asm-generic: Add new pci.h and use it
Date: Fri, 22 Jul 2022 21:55:03 +0200 [thread overview]
Message-ID: <CAK8P3a2aTS74TG8F+cVHX969hMQHKP3Ai5V0h-m+GeAq6kq5pQ@mail.gmail.com> (raw)
In-Reply-To: <CAL_JsqJHZEcnJi+UHQbYWVoy1okQjHSc9T377P1q8oOJnHBWFw@mail.gmail.com>
On Fri, Jul 22, 2022 at 6:36 PM Rob Herring <robh@kernel.org> wrote:
> On Fri, Jul 22, 2022 at 9:27 AM Palmer Dabbelt <palmer@dabbelt.com> wrote:
>
> From fu740:
> ranges = <0x81000000 0x0 0x60080000 0x0
> 0x60080000 0x0 0x10000>, /* I/O */
...
> So again, how does one get a 0 address handed out when that's not even
> a valid region according to DT? Is there some legacy stuff that
> ignores the bridge windows?
The PCI-side port number 0x60080000 gets turned into Linux I/O resource 0,
which I think is what __pci_assign_resource operates on.
The other question is why the platform would want to configure the
PCI bus to have a PCI I/O space window of size 0x10000 at the address
it's mapped into, rather than putting it at address zero. Is this a hardware
bug, a bootloader bug, or just badly set up in the DT?
Putting the PCI address of the I/O space window at port 0 is usually
better because it works with PCI devices and drivers that assume that
port numbers are below 0xfffff, and makes the PCI port number match
the Linux port number.
Arnd
next prev parent reply other threads:[~2022-07-22 19:55 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220718004114.3925745-1-shorne@gmail.com>
2022-07-18 0:41 ` [PATCH v3 1/2] asm-generic: Remove pci.h copying remaining code to x86 Stafford Horne
2022-07-18 8:22 ` Geert Uytterhoeven
2022-07-19 12:02 ` Pierre Morel
2022-07-18 0:41 ` [PATCH v3 2/2] asm-generic: Add new pci.h and use it Stafford Horne
2022-07-19 15:58 ` Palmer Dabbelt
2022-07-21 22:05 ` Stafford Horne
2022-07-21 22:53 ` Palmer Dabbelt
2022-07-21 23:06 ` Rob Herring
2022-07-22 10:53 ` Arnd Bergmann
2022-07-22 15:27 ` Palmer Dabbelt
2022-07-22 16:36 ` Rob Herring
2022-07-22 19:23 ` Maciej W. Rozycki
2022-07-22 19:42 ` Rob Herring
2022-07-22 22:28 ` Maciej W. Rozycki
2022-07-22 19:55 ` Arnd Bergmann [this message]
2022-07-22 21:39 ` Jessica Clarke
2022-07-22 21:44 ` Rob Herring
2022-07-22 22:41 ` Maciej W. Rozycki
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=CAK8P3a2aTS74TG8F+cVHX969hMQHKP3Ai5V0h-m+GeAq6kq5pQ@mail.gmail.com \
--to=arnd@arndb.de \
--cc=anton.ivanov@cambridgegreys.com \
--cc=aou@eecs.berkeley.edu \
--cc=bhelgaas@google.com \
--cc=catalin.marinas@arm.com \
--cc=guoren@kernel.org \
--cc=johannes@sipsolutions.net \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-csky@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=linux-um@lists.infradead.org \
--cc=macro@orcam.me.uk \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=richard@nod.at \
--cc=robh@kernel.org \
--cc=shorne@gmail.com \
--cc=will@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).