[Linux-ia64] Linux page tables and VHPT

[Linux-ia64] Linux page tables and VHPT

[Christian Hildner]

Hi all!

After reading and understanding (that took some time) the VHPT feature I

looked through the sources, but there are some questions left about the
use of the processor's VHPT.

- which of the page tables are used as base address in cr.pta?

- where is the virtual page table located?

- which size has the virtual page table?

- is the VHPT used for both the kernel and the userspace mappings?

If anyone knows answers to my questions you'd be welcome.

Christian

Re: [Linux-ia64] Linux page tables and VHPT

[David Mosberger]

>>>>> On Fri, 14 Dec 2001 14:21:43 +0100, Christian Hildner <christian.hildner@hob.de> said:

  Christian> Hi all!  After reading and understanding (that took some
  Christian> time) the VHPT feature I

  Christian> looked through the sources, but there are some questions
  Christian> left about the use of the processor's VHPT.
  Christian> - which of the page tables are used as base address in cr.pta?

pta is always set to a fixed address.  The address is calculated based
on the number of address bits supported by the CPU.

  Christian> - where is the virtual page table located?

Each region that uses the VHPT has its own virtual page table, at the
offset configured in cr.pta.

  Christian> - which size has the virtual page table?

See above.

  Christian> - is the VHPT used for both the kernel and the userspace mappings?

Yes. ;-)

Regions 6 and 7 don't use the VHPT, the remaining regions do
(including region 5, which is the page-table mapped region of the
kernel).

  Christian> If anyone knows answers to my questions you'd be welcome.

My book describes this in a fair amount of detail.  It's not out yet,
but will be starting in February.  For table-of-contents etc., see the
URL below.

	--david

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