Hello Jan,
First of all, thanks for your quick answer.
Yes, you're completely right. My user application called rt_dev_ioctl, which
eventually called rtdm_iomap_to_user, after rt_task_shadow. Now, I call it just
after mlockall and rt_dev_open, and before rt_task_shadow. The
rtdm_iomap_to_user function now seems to be working correctly, and dmesg no
longer shows the previous errors. [By the way, it could be interesting to add a
rtdm_in_rt_context() check in the rtdm_iomap_to_user function, which would
return an error if in RT]
However, when I later try to write to the device, nothing is written. The mmap
seems not to be correct. The following lines may show the problem:
rtdm_printk("location %lx --> base %p --> iomap_to_user %p -->
virt_to_phys %lx \n",
my_context->location, my_context->base_address, new_iomap,
virt_to_phys(new_iomap));
gives the following result:
location 20000000 -> base e0a00000 --> iomap_to_user b5f6f000 -->
virt_to_phys f5f6f000
where the variables are:
[unsigned long] xen_mydriver->location = pci_resource_start(dev,0);
[void __iomem*] xen_mydriver->base_address =
ioremap(xen_mydriver->location, xen_mydriver->mem_size);
[void __iomem*] new_iomap
rtdm_iomap_to_user(user_info,my_context->location, 300,
PROT_READ|PROT_WRITE, &new_iomap, NULL, NULL);
If I execute in my RTDM driver:
*(unsigned short*)(my_context->base_address + 0x100) = 0xAAAA;
I can see that the address is written. However, if I execute (either in the
driver or from the RT task):
*(unsigned short*)(new_iomap + 0x100) = 0xAAAA;
It doesn't work.
Does anybody know what is wrong? I'm sure I must be missing something
important, but I can't see what.
Best regards,
Asier
> -----Original Message-----
> From: Jan Kiszka [mailto:[email protected]]
> Sent: Thursday, April 14, 2011 9:34 AM
> To: Asier Tamayo
> Cc: [email protected]
> Subject: Re: FW: rtdm_iomap_to_user() I-pipe error
>
>
> On 2011-04-14 08:14, Asier Tamayo wrote:
> >
> > Hello,
> >
> > I'm porting a PCI driver to a RTDM. Until now, I have
> successfully done most of the job.
> >
> > I'm using Xenomai version 2.4.7 and Linux 2.6.27, from the
> ELinOS 5.0 distribution.
> >
> > My problem appears with the rtdm_iomap_to_user() function.
> I want to allow a RT task to access the PCI memory directly,
> via mmap. As the RTDM has no mmap() function, I'm trying to
> use rtdm_iomap_to_user, but it always gives me the following error:
> >
> > I-pipe: Detected illicit call from domain 'Xenomai'
> > into a service reserved for domain 'Linux' and below.
>
> This is also documented: rtdm_iomap_to_user is not supposed
> to be called
> from RT task context. This means your driver should only call it from
> handlers registered for *_nrt entry points.
>
> Jan
>
> --
> Siemens AG, Corporate Technology, CT T DE IT 1
> Corporate Competence Center Embedded Linux
>
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