ioremap and page table

[ckim at etri.re.kr]

Ah, yes of course the virtual address. Thanks for pointing it out!

Chan Kim

 

From: Deepanshu Kartikey <kartikey406 at gmail.com> 
Sent: Monday, July 12, 2021 1:48 AM
To: ckim at etri.re.kr
Cc: kernelnewbies at kernelnewbies.org
Subject: Re: ioremap and page table

 

 

What my understanding is that ioremap converts your address to a virtual address. So, yes everything then is handled by the kernel

 

 

 

On Sun, Jul 11, 2021 at 9:04 PM <ckim at etri.re.kr <mailto:ckim at etri.re.kr> > wrote:

Hello all,

I’m almost sure but want to check if my understanding is correct.

To use a memory mapped IO, we use functions like request_mem_region and ioremap, iounmap functions. 

I guess when we call ioremap function, the kernel sets up page table for the region so that the region becomes non-cacheable, and I don’t also have  to worry about reordering problem. 

Is my understanding correct?

Thanks!

Chan Kim

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