Is there a utility to peek and poke PCIe devices

  • Thread starter General Schvantzkoph
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General Schvantzkoph

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Is there a utility that does peeks and pokes to PCIe devices. I'm
developing an FPGA with a PCIe interface and I'd like to do some simple
memory accesses before I move on to the more complicated things like DMA.
We have a driver in development but I think there is a standard Altera
driver already in the kernel which I assume would be good enough for
simple accesses.

I'm running on Scientific Linux 6.1.

lspci identifies the device as an Altera device which is correct.

01:00.0 Unassigned class [ff00]: Altera Corporation Device 0004 (rev 01)
 
On 08/10/11 23:39, General Schvantzkoph wrote:
Is there a utility that does peeks and pokes to PCIe devices. I'm
developing an FPGA with a PCIe interface and I'd like to do some simple
memory accesses before I move on to the more complicated things like DMA.
We have a driver in development but I think there is a standard Altera
driver already in the kernel which I assume would be good enough for
simple accesses.

I'm running on Scientific Linux 6.1.

lspci identifies the device as an Altera device which is correct.

01:00.0 Unassigned class [ff00]: Altera Corporation Device 0004 (rev 01)
Click to expand...
you don't even need a driver for simple memory access. if your device is
detected by the kernel you can directly access the BARs via sysfs:
# ls -l /sys/bus/pci/devices/0000\:01\:00.0/
[...]
-rw------- 1 root root 256M Aug 11 08:51 resource0
-rw------- 1 root root 256 Aug 11 08:51 resource1
-rw------- 1 root root 64K Aug 2 08:14 resource2
[...]

This is an example of a device with 3 BARs. These files can be
read/written/mmapped... you could use "dd" or write a little C program
to mmap the files.

HTH
 
In comp.arch.fpga rndhro <rnd@hro.org> wrote:
On 08/10/11 23:39, General Schvantzkoph wrote:
Is there a utility that does peeks and pokes to PCIe devices.
Click to expand...
(snip)
you don't even need a driver for simple memory access. if your device is
detected by the kernel you can directly access the BARs via sysfs:
# ls -l /sys/bus/pci/devices/0000\:01\:00.0/
[...]
-rw------- 1 root root 256M Aug 11 08:51 resource0
-rw------- 1 root root 256 Aug 11 08:51 resource1
-rw------- 1 root root 64K Aug 2 08:14 resource2
[...]
Click to expand...
I remember doing this with VME based Suns and SunOS.
Device mapped VME addressing space, and memory mapped files
combine to form memory mapped memory space.

-- glen
 
On Thu, 11 Aug 2011 08:57:05 +0200, rndhro wrote:

On 08/10/11 23:39, General Schvantzkoph wrote:
Is there a utility that does peeks and pokes to PCIe devices. I'm
developing an FPGA with a PCIe interface and I'd like to do some simple
memory accesses before I move on to the more complicated things like
DMA. We have a driver in development but I think there is a standard
Altera driver already in the kernel which I assume would be good enough
for simple accesses.

I'm running on Scientific Linux 6.1.

lspci identifies the device as an Altera device which is correct.

01:00.0 Unassigned class [ff00]: Altera Corporation Device 0004 (rev
01)

you don't even need a driver for simple memory access. if your device is
detected by the kernel you can directly access the BARs via sysfs: # ls
-l /sys/bus/pci/devices/0000\:01\:00.0/ [...]
-rw------- 1 root root 256M Aug 11 08:51 resource0 -rw------- 1 root
root 256 Aug 11 08:51 resource1 -rw------- 1 root root 64K Aug 2
08:14 resource2 [...]

This is an example of a device with 3 BARs. These files can be
read/written/mmapped... you could use "dd" or write a little C program
to mmap the files.

HTH
Click to expand...
How do I determine which device is mine?

Here is the lspci output
01:00.0 Unassigned class [ff00]: Altera Corporation Device 0004 (rev 01)

Here are the devices under /sys/bus/pci_express/devices

0000:00:0b.0:pcie01/ 0000:00:0c.0:pcie01/ 0000:00:0d.0:pcie01/
0000:00:0e.0:pcie01/
0000:00:0b.0:pcie08/ 0000:00:0c.0:pcie08/ 0000:00:0d.0:pcie08/
0000:00:0e.0:pcie08

Here are the devices under /sys/bus/pci/devices

0000:00:00.0/ 0000:00:02.0/ 0000:00:06.0/ 0000:00:09.0/
0000:00:0c.0/ 0000:00:18.0/ 0000:00:18.3/ 0000:05:00.0/
0000:00:01.0/ 0000:00:02.1/ 0000:00:07.0/ 0000:00:0a.0/
0000:00:0d.0/ 0000:00:18.1/ 0000:01:0d.0/
0000:00:01.1/ 0000:00:04.0/ 0000:00:08.0/ 0000:00:0b.0/
0000:00:0e.0/ 0000:00:18.2/ 0000:03:00.0
 
How do I determine which device is mine?

Here is the lspci output
01:00.0 Unassigned class [ff00]: Altera Corporation Device 0004 (rev 01)
Click to expand...
you should be able to use the pci-ID from lspci as directory name in
/sys/bus/pcie/devices/

Here are the devices under /sys/bus/pci/devices

0000:00:00.0/ 0000:00:02.0/ 0000:00:06.0/ 0000:00:09.0/
0000:00:0c.0/ 0000:00:18.0/ 0000:00:18.3/ 0000:05:00.0/
0000:00:01.0/ 0000:00:02.1/ 0000:00:07.0/ 0000:00:0a.0/
0000:00:0d.0/ 0000:00:18.1/ 0000:01:0d.0/
0000:00:01.1/ 0000:00:04.0/ 0000:00:08.0/ 0000:00:0b.0/
0000:00:0e.0/ 0000:00:18.2/ 0000:03:00.0
Click to expand...
I don't really know why your device 0000:01:00.0 doesn't appear here -
did you list the directory on the same machine & while the card is
detected? Just a guess: maybe you have to set a device class in the FPGA
Firmware other than ff00? (my Xilinx ML605 gets detected as "RAM memory"
for example by setting the appropriate device/vendor IDs)
 
On Thu, 11 Aug 2011 15:55:33 +0200, rndhro wrote:

How do I determine which device is mine?

Here is the lspci output
01:00.0 Unassigned class [ff00]: Altera Corporation Device 0004 (rev
01)

you should be able to use the pci-ID from lspci as directory name in
/sys/bus/pcie/devices/

Here are the devices under /sys/bus/pci/devices

0000:00:00.0/ 0000:00:02.0/ 0000:00:06.0/ 0000:00:09.0/
0000:00:0c.0/
0000:00:18.0/ 0000:00:18.3/ 0000:05:00.0/ 0000:00:01.0/
0000:00:02.1/
0000:00:07.0/ 0000:00:0a.0/ 0000:00:0d.0/ 0000:00:18.1/
0000:01:0d.0/
0000:00:01.1/ 0000:00:04.0/ 0000:00:08.0/ 0000:00:0b.0/
0000:00:0e.0/
0000:00:18.2/ 0000:03:00.0

I don't really know why your device 0000:01:00.0 doesn't appear here -
did you list the directory on the same machine & while the card is
detected? Just a guess: maybe you have to set a device class in the FPGA
Firmware other than ff00? (my Xilinx ML605 gets detected as "RAM memory"
for example by setting the appropriate device/vendor IDs)
Click to expand...
I'm switching the class to 5 from FF, I'll see what happens.
 
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