linux-kernel - Re: PCIe interface memory memory mapping issue

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: <51f3faa70906140926p2e34cb47j1ad8e9332c893c0d@mail.gmail.com>
Date:	Sun, 14 Jun 2009 10:26:12 -0600
From:	Robert Hancock <hancockrwd@...il.com>
To:	Sanka Piyaratna <cesanka@...oo.com>
Cc:	linux-kernel@...r.kernel.org
Subject: Re: PCIe interface memory memory mapping issue

On Sun, Jun 14, 2009 at 6:43 AM, Sanka Piyaratna<cesanka@...oo.com> wrote:
>
> Hi Robert
>
>
> Thanks for your reply.
>
>>> I have developed a PCI express interface using Xilinx ML555 hardware module. I have implemented Linux kernel >>mode device drivers and everything works correctly as long as I am using the device within a computer with dual >>channel DDR arrangement. However, as soon as I pug this device into a core i7 or an older single channel DDR >>machine, the interface memory mapping does not work any more. As if the register map with in the device does no >>longer exsists. However, "lspci" utility provides correct information. I am not sure if this has anything to do with the >>number of DDR memory channels the motherboard has or why that would be a problem for PCI express device. >>However, this seem to be the common link between the machines that demonstrate this issue.
>
>>You'll have to give more details on what you mean by "the interface memory mapping does not work any more. As if >the register map with in the device does no longer exsists".
>
> What I mean by this is that, when load the driver, the memory mapping of the hardware memory onto the computer memory does not work. I have a setup where I have all the control registers in BAR5 (512 byte) and I also have 64kB chuck of the FPGA memory mapped using BAR0. I am not able to see the register space when the BAR5 area in the computer memory map. However, I am able to write something to BAR0 memory map and read it back.

How are you getting the register space into the memory map.. ioremap() ?
--
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/