From mboxrd@z Thu Jan  1 00:00:00 1970
From: Bjorn Helgaas <bhelgaas@google.com>
Subject: Re: [PATCH 10/13] PCI: Strict checking of valid range for bridge
Date: Mon, 30 Jan 2012 08:04:39 -0800
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References: <1327718971-9598-1-git-send-email-yinghai@kernel.org> <1327718971-9598-11-git-send-email-yinghai@kernel.org>
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To: Yinghai Lu <yinghai@kernel.org>
Cc: Jesse Barnes <jbarnes@virtuousgeek.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, Tony Luck <tony.luck@intel.com>, Linus Torvalds <torvalds@linux-foundation.org>, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org

On Fri, Jan 27, 2012 at 6:49 PM, Yinghai Lu <yinghai@kernel.org> wrote:
> children bridges busn range should be able to be allocated from paren=
t bus range.
>
> to avoid overlapping between sibling bridges on same bus.
>
> Signed-off-by: Yinghai Lu <yinghai@kernel.org>
> ---
> =A0drivers/pci/probe.c | =A0 27 +++++++++++++++++++++++++++
> =A01 files changed, 27 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 83df3fb..e12f65f0 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -791,6 +791,33 @@ reduce_needed_size:
> =A0 =A0 =A0 =A0return ret;
> =A0}
>
> +static int __devinit pci_bridge_check_busn_res(struct pci_bus *bus,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 struct =
pci_dev *dev,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 int sec=
ondary, int subordinate)

This function returns a boolean, but the function name doesn't give
any clue about what a true/false return means.  Something like
"busn_valid" would make the callers more readable.

> +{
> + =A0 =A0 =A0 int broken =3D 0;
> +
> + =A0 =A0 =A0 struct resource busn_res;
> + =A0 =A0 =A0 int ret;
> +
> + =A0 =A0 =A0 memset(&busn_res, 0, sizeof(struct resource));
> + =A0 =A0 =A0 dev_printk(KERN_DEBUG, &dev->dev,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0"check if busn %02x-%02x is in busn_=
res: %06llx-%06llx\n",
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0secondary, subordinate,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(unsigned long long)bus->busn_res.st=
art,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(unsigned long long)bus->busn_res.en=
d);
> + =A0 =A0 =A0 ret =3D allocate_resource(&bus->busn_res, &busn_res,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(subordinate - secon=
dary + 1),
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(pci_domain_nr(bus)<=
<8) | secondary,
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0(pci_domain_nr(bus)<=
<8) | subordinate,

I think this "(pci_domain_nr(bus)<<8) | secondary" stuff needs to be a
macro or something.

> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A01, NULL, NULL);
> + =A0 =A0 =A0 if (ret)
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 broken =3D 1;
> + =A0 =A0 =A0 else
> + =A0 =A0 =A0 =A0 =A0 =A0 =A0 release_resource(&busn_res);
> +
> + =A0 =A0 =A0 return broken;
> +}
> =A0/*
> =A0* If it's a bridge, configure it and scan the bus behind it.
> =A0* For CardBus bridges, we don't scan behind as the devices will
> --
> 1.7.7
>