Re: [RFC:PATCH 02/03] powerpc: Add definitions for Debug Registers on BookE Platforms

Kumar Gala
2009-12-11T14:35:35Z

On Dec 10, 2009, at 9:28 PM, David Gibson wrote:

> On Thu, Dec 10, 2009 at 08:41:53PM -0600, Kumar Gala wrote:
> [snip]
>>> +#define DBCR1_USER_DEBUG (DBCR1_IAC12M | DBCR1_IAC34M)
>>> +#define DBCR1_BASE_REG_VALUE (DBCR1_IAC1US | DBCR1_IAC1ER_10 =
| \
>>> + DBCR1_IAC2US | DBCR1_IAC2ER_10 | \
>>> + DBCR1_IAC3US | DBCR1_IAC3ER_10 | \
>>> + DBCR1_IAC4US | DBCR1_IAC4ER_10)
>>=20
>> We are we using MSR[IS] IS=3D0, why not just any Eff address? In the
>> future we might have user as IS =3D 1, and kernel as IS =3D 0.
>=20
> Since the user can't control that directly, we can update this when
> and if we change our use of address spaces.

That's such a subtle issue (easy to forgot about and miss in the =
future). Why do we need this now?

- k=