RE: question about ioport_map function

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Oh my question contains discrepancy.

My real question is whether the output of ioport_map is physical or virtual. (I’m confused)

I know for systems with memory mapped I/O, we can just use request_mem_region, ioremap (maps to virtual address), plain memory access for the peripheral. (the page table sets the area as uncacheable because it’s IO devices)

Thanks!

Chan Kim

 

From: ckim@xxxxxxxxxx <ckim@xxxxxxxxxx>
Sent: Monday, March 22, 2021 10:28 AM
To: kernelnewbies@xxxxxxxxxxxxxxxxx
Subject: question about ioport_map function

 

Hello all

From what I understand, to map io ports to virtual memory, we should use request_region, ioport_map/unmap and ioread/write functions.

These are for architectures having input, output machine instructions like x86, x86_64.

And the return address of ioport_map is physical address.

Is my understanding correct?

Thanks!

Chan Kim

 

_______________________________________________
Kernelnewbies mailing list
Kernelnewbies@xxxxxxxxxxxxxxxxx
https://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies

[Index of Archives]     [Newbies FAQ]     [Linux Kernel Mentors]     [Linux Kernel Development]     [IETF Annouce]     [Git]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux RAID]     [Linux SCSI]     [Linux ACPI]

  Powered by Linux