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* 64bit MMIO access
@ 2013-02-28 21:46 Jagath Weerasinghe
  2013-02-28 21:53 ` Jagath Weerasinghe
  2013-02-28 22:15 ` Valdis.Kletnieks at vt.edu
  0 siblings, 2 replies; 6+ messages in thread
From: Jagath Weerasinghe @ 2013-02-28 21:46 UTC (permalink / raw)
  To: kernelnewbies

Hi,

What are the read/write kernel functions to access 64bit MMIO addresses?
Are there similar functions like readl() and writel() for 64bit systems?

Regards,
Jagath

^ permalink raw reply	[flat|nested] 6+ messages in thread

* 64bit MMIO access
  2013-02-28 21:46 64bit MMIO access Jagath Weerasinghe
@ 2013-02-28 21:53 ` Jagath Weerasinghe
  2013-02-28 22:15 ` Valdis.Kletnieks at vt.edu
  1 sibling, 0 replies; 6+ messages in thread
From: Jagath Weerasinghe @ 2013-02-28 21:53 UTC (permalink / raw)
  To: kernelnewbies

Hi,

What are the read/write kernel functions to access 64bit MMIO addresses?
Are there similar functions like readl() and writel() for 64bit systems?

Regards,
Jagath

^ permalink raw reply	[flat|nested] 6+ messages in thread

* 64bit MMIO access
  2013-02-28 21:46 64bit MMIO access Jagath Weerasinghe
  2013-02-28 21:53 ` Jagath Weerasinghe
@ 2013-02-28 22:15 ` Valdis.Kletnieks at vt.edu
  2013-03-10 19:35   ` Jagath Weerasinghe
  1 sibling, 1 reply; 6+ messages in thread
From: Valdis.Kletnieks at vt.edu @ 2013-02-28 22:15 UTC (permalink / raw)
  To: kernelnewbies

On Thu, 28 Feb 2013 22:46:58 +0100, Jagath Weerasinghe said:
> What are the read/write kernel functions to access 64bit MMIO addresses?
> Are there similar functions like readl() and writel() for 64bit systems?

Are there any actual real-world cards that support 64-bit addressing
but still require MMIO?
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^ permalink raw reply	[flat|nested] 6+ messages in thread

* 64bit MMIO access
  2013-02-28 22:15 ` Valdis.Kletnieks at vt.edu
@ 2013-03-10 19:35   ` Jagath Weerasinghe
  2013-03-11  3:43     ` Valdis.Kletnieks at vt.edu
  2013-03-11  3:44     ` Valdis.Kletnieks at vt.edu
  0 siblings, 2 replies; 6+ messages in thread
From: Jagath Weerasinghe @ 2013-03-10 19:35 UTC (permalink / raw)
  To: kernelnewbies

Hi,

readq and writeq do the job.



On Thu, Feb 28, 2013 at 11:15 PM,  <Valdis.Kletnieks@vt.edu> wrote:
> On Thu, 28 Feb 2013 22:46:58 +0100, Jagath Weerasinghe said:
>> What are the read/write kernel functions to access 64bit MMIO addresses?
>> Are there similar functions like readl() and writel() for 64bit systems?
>
> Are there any actual real-world cards that support 64-bit addressing
> but still require MMIO?

^ permalink raw reply	[flat|nested] 6+ messages in thread

* 64bit MMIO access
  2013-03-10 19:35   ` Jagath Weerasinghe
@ 2013-03-11  3:43     ` Valdis.Kletnieks at vt.edu
  2013-03-11  3:44     ` Valdis.Kletnieks at vt.edu
  1 sibling, 0 replies; 6+ messages in thread
From: Valdis.Kletnieks at vt.edu @ 2013-03-11  3:43 UTC (permalink / raw)
  To: kernelnewbies

On Sun, 10 Mar 2013 20:35:37 +0100, Jagath Weerasinghe said:
> readq and writeq do the job.

Please double-check how those are implemented on your architecture. I seem
to remember that on some systems, readq and writeq may not be atomic and
may become two bus cycles.  And some hardware cares about that.

It was a discussion on linux-kernel maybe a year or so ago...
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* 64bit MMIO access
  2013-03-10 19:35   ` Jagath Weerasinghe
  2013-03-11  3:43     ` Valdis.Kletnieks at vt.edu
@ 2013-03-11  3:44     ` Valdis.Kletnieks at vt.edu
  1 sibling, 0 replies; 6+ messages in thread
From: Valdis.Kletnieks at vt.edu @ 2013-03-11  3:44 UTC (permalink / raw)
  To: kernelnewbies

On Sun, 10 Mar 2013 20:35:37 +0100, Jagath Weerasinghe said:
> Hi,
>
> readq and writeq do the job.

(hit send too soon)  Also, the read/write [bwlq] functions refer to the width
of the *data*, not the address....

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^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2013-03-11  3:44 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-02-28 21:46 64bit MMIO access Jagath Weerasinghe
2013-02-28 21:53 ` Jagath Weerasinghe
2013-02-28 22:15 ` Valdis.Kletnieks at vt.edu
2013-03-10 19:35   ` Jagath Weerasinghe
2013-03-11  3:43     ` Valdis.Kletnieks at vt.edu
2013-03-11  3:44     ` Valdis.Kletnieks at vt.edu

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