[RFC, PATCH 1/2] arm: don't check MMU status in every addruart macro
nico at fluxnic.net
Mon Jul 12 09:32:17 EDT 2010
On Mon, 12 Jul 2010, Jeremy Kerr wrote:
> Rather than checking the MMU status in every instance of addruart, do it
> once in kernel/debug.S, and change the existing addruart macros to
> expect the uart status in the macro argument register.
> This will also allow us to retreive the address of a uart for the MMU
> state that we're not current in.
> Signed-off-by: Jeremy Kerr <jeremy.kerr at canonical.com>
Many issues with this:
- __addruart vs addruart is rather confusing. Normally the __xyz form
is used by the higher level xyz which is opposite to what is done
- While at it, this should be replaced altogether by a macro that simply
returns both the physical address and the virtual address for the
debugging IO peripheral to use. This would make your patch #2 much
straight forward too.
- The test to determine whether the MMU is active and select the
appropriate address to use should remain close together and actually
can be moved to a common place instead of being duplicated everywhere.
The code is really testing a specific bit in a hardware register, and
with this patch that now looks as if this was a simple boolean
argument which is not a good thing.
More information about the linux-arm-kernel