linux-kernel - Re: [PATCH 05/14] lib: Add I/O map cache implementation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <201301101826.56248.arnd@arndb.de>
Date:	Thu, 10 Jan 2013 18:26:55 +0000
From:	Arnd Bergmann <arnd@...db.de>
To:	Thierry Reding <thierry.reding@...onic-design.de>
Cc:	Jason Gunthorpe <jgunthorpe@...idianresearch.com>,
	Stephen Warren <swarren@...dotorg.org>,
	linux-tegra@...r.kernel.org,
	Grant Likely <grant.likely@...retlab.ca>,
	Rob Herring <rob.herring@...xeda.com>,
	Russell King <linux@....linux.org.uk>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Andrew Murray <andrew.murray@....com>,
	Thomas Petazzoni <thomas.petazzoni@...e-electrons.com>,
	devicetree-discuss@...ts.ozlabs.org, linux-kernel@...r.kernel.org,
	linux-arm-kernel@...ts.infradead.org, linux-pci@...r.kernel.org
Subject: Re: [PATCH 05/14] lib: Add I/O map cache implementation

On Thursday 10 January 2013, Thierry Reding wrote:
> I don't understand how this would help. The encoding is like this:
> 
>         [27:24] extended register number
>         [23:16] bus number
>         [15:11] device number
>         [10: 8] function number
>         [ 7: 0] register number
> 
> So it doesn't matter whether I use separate areas per bus or not. As
> soon as the whole extended configuration space needs to be accessed a
> whopping 28 bits (256 MiB) are required.
> 
> What you propose would work if only regular configuration space is
> supported. I'm not sure if that's an option.

I mean something like:

struct tegra_bus_private {
	...
	void __iomem *config_space[16];
};


void tegra_scan_bus(struct pci_bus *bus)
{
	int i;
	struct tegra_bus_private *priv = bus->dev->private;

	for (i=0; i<16; i++)
		priv->config_space[i] = ioremap(config_space_phys +
				 65536 * bus->primary + i * SZ_1M, 65536);

	...
}

	Arnd
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/