Difference between ioremap() and phy_to_virt() Kernel function

Difference between ioremap() and phy_to_virt() Kernel function

[Misbah khan]

Hi all

Could you Please let me know what is the difference between ioremap() and
phy_to_virt() function being provided by the Kernel. 

--Misbah
-- 
View this message in context: http://www.nabble.com/Difference-between-ioremap%28%29-and-phy_to_virt%28%29-Kernel-function-tf4669833.html#a13339930
Sent from the linuxppc-embedded mailing list archive at Nabble.com.

Re: Difference between ioremap() and phy_to_virt() Kernel function

[Arnd Bergmann]

On Monday 22 October 2007, Misbah khan wrote:
> Could you Please let me know what is the difference between ioremap() and
> phy_to_virt() function being provided by the Kernel.

ioremap gives you a new mapping for I/O addresses that you can access
with functions like in_be32 and the like.

phy_to_virt() is rarely used at all, it only serves to convert a physical
address for main memory (RAM) into the address used inside of the kernel.

	Arnd <><

Re: Difference between ioremap() and phy_to_virt() Kernel function

[Misbah khan]

Thanks Arnd 

But i wish to know that could i use phy_to_virt() function in place io
ioremap() ????? And could you give me an example where we could use
phy_to_virt(). ioremap() implementation i have already done.

---Misbah


Arnd Bergmann wrote:
> 
> On Monday 22 October 2007, Misbah khan wrote:
>> Could you Please let me know what is the difference between ioremap() and
>> phy_to_virt() function being provided by the Kernel.
> 
> ioremap gives you a new mapping for I/O addresses that you can access
> with functions like in_be32 and the like.
> 
> phy_to_virt() is rarely used at all, it only serves to convert a physical
> address for main memory (RAM) into the address used inside of the kernel.
> 
> 	Arnd <><
> _______________________________________________
> Linuxppc-embedded mailing list
> Linuxppc-embedded@ozlabs.org
> https://ozlabs.org/mailman/listinfo/linuxppc-embedded
> 
> 

-- 
View this message in context: http://www.nabble.com/Difference-between-ioremap%28%29-and-phy_to_virt%28%29-Kernel-function-tf4669833.html#a13357088
Sent from the linuxppc-embedded mailing list archive at Nabble.com.

Re: Difference between ioremap() and phy_to_virt() Kernel function

[Arnd Bergmann]

On Tuesday 23 October 2007, Misbah khan wrote:
> But i wish to know that could i use phy_to_virt() function in place io
> ioremap() ?????

Sorry to disappoint you there, but you can't.

> And could you give me an example where we could use phy_to_virt().

Not really, I can't think of any correct use of phys_to_virt on powerpc.

	Arnd <><