* [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c
@ 2004-08-27 11:34 Andrey Volkov
2004-08-27 14:15 ` Kumar Gala
2004-08-27 15:00 ` Dan Malek
0 siblings, 2 replies; 6+ messages in thread
From: Andrey Volkov @ 2004-08-27 11:34 UTC (permalink / raw)
To: linuxppc-embedded
Hello all,
Since G2_LE is NOT a "classic" core ( in particular - true little-endian),
may be now is time to remove it from CLASSIC_PPC part of
arch/ppc/kernel/cputable.c, and move it to itself part.
I bear in mind next:
from arch/ppc/kernel/cputable.c:
#if CLASSIC_PPC
.....
{ /* All G2_LE (603e core, plus some) have the same pvr */
0x7fff0000, 0x00820000, "G2_LE",
CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_CAN_DOZE | CPU_FTR_USE_TB |
CPU_FTR_CAN_NAP | CPU_FTR_HAS_HIGH_BATS,
COMMON_PPC,
32, 32,
__setup_cpu_603
},
....
#endif /* CLASSIC_PPC */
May be better like this:
#if CONFIG_G2_LE
{ /* All G2_LE (603e core, plus some) have the same pvr */
0x7fff0000, 0x00820000, "G2_LE",
CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_CAN_DOZE | CPU_FTR_USE_TB |
CPU_FTR_CAN_NAP | CPU_FTR_HAS_HIGH_BATS,
COMMON_PPC,
32, 32,
__setup_cpu_603
},
#endif
With that move we'll conserve some memory of kernel,
but need some explanations which PPCs based on
it, for modify Kconfig ( I know MPC52xx and MPC82xx based on it).
--
Best regards,
Andrey Volkov
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c
2004-08-27 11:34 [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c Andrey Volkov
@ 2004-08-27 14:15 ` Kumar Gala
2004-08-27 15:00 ` Re[2]: " Andrey Volkov
2004-08-27 15:00 ` Dan Malek
1 sibling, 1 reply; 6+ messages in thread
From: Kumar Gala @ 2004-08-27 14:15 UTC (permalink / raw)
To: Andrey Volkov; +Cc: linuxppc-embedded
What purpose does this change really serve. Linux does not use the
true little-endian feature of the G2_LE core, beyond that it is very
much in the class of classic ppc. Is the memory savings really that
much?
- kumar
On Aug 27, 2004, at 6:34 AM, Andrey Volkov wrote:
>
> Hello all,
>
> Since G2_LE is NOT a "classic" core ( in particular - true
> little-endian),
> may be now is time to remove it from CLASSIC_PPC part of
> arch/ppc/kernel/cputable.c, and move it to itself part.
> I bear in mind next:
>
> from arch/ppc/kernel/cputable.c:
>
> #if CLASSIC_PPC
> .....
> { /* All G2_LE (603e core, plus some) have the same pvr */
> 0x7fff0000, 0x00820000, "G2_LE",
> CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_CAN_DOZE | CPU_FTR_USE_TB |
> CPU_FTR_CAN_NAP | CPU_FTR_HAS_HIGH_BATS,
> COMMON_PPC,
> 32, 32,
> __setup_cpu_603
> },
> ....
> #endif /* CLASSIC_PPC */
>
> May be better like this:
>
> #if CONFIG_G2_LE
> { /* All G2_LE (603e core, plus some) have the same pvr */
> 0x7fff0000, 0x00820000, "G2_LE",
> CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_CAN_DOZE | CPU_FTR_USE_TB |
> CPU_FTR_CAN_NAP | CPU_FTR_HAS_HIGH_BATS,
> COMMON_PPC,
> 32, 32,
> __setup_cpu_603
> },
> #endif
>
> With that move we'll conserve some memory of kernel,
> but need some explanations which PPCs based on
> it, for modify Kconfig ( I know MPC52xx and MPC82xx based on it).
>
> --
> Best regards,
> Andrey Volkov
>
>
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread* Re[2]: [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c
2004-08-27 14:15 ` Kumar Gala
@ 2004-08-27 15:00 ` Andrey Volkov
0 siblings, 0 replies; 6+ messages in thread
From: Andrey Volkov @ 2004-08-27 15:00 UTC (permalink / raw)
To: Kumar Gala; +Cc: linuxppc-embedded
Hello Kumar,
Friday, August 27, 2004, 6:15:20 PM, you wrote:
> What purpose does this change really serve. Linux does not use the
> true little-endian feature of the G2_LE core, beyond that it is very
> much in the class of classic ppc.
> Is the memory savings really that much?
sizeof(*cpu_table) ~ 1300 bytes
+ code in cpu_setup_6xx.S ~ 1000 bytes
+ more simple to filter out some features in Kconfig (ex. SMP,
ALTIVEC...)
And optionally (?):
+ LE (if it will be needed sometime for somebody)
+ "An additional input interrupt signal, core_cint,
implements a critical interrupt function."
>>
>> Since G2_LE is NOT a "classic" core ( in particular - true
>> little-endian),
>> may be now is time to remove it from CLASSIC_PPC part of
>> arch/ppc/kernel/cputable.c, and move it to itself part.
>> I bear in mind next:
>>
>> from arch/ppc/kernel/cputable.c:
>>
>> #if CLASSIC_PPC
>> .....
>> { /* All G2_LE (603e core, plus some) have the same pvr */
>> 0x7fff0000, 0x00820000, "G2_LE",
>> CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_CAN_DOZE | CPU_FTR_USE_TB |
>> CPU_FTR_CAN_NAP | CPU_FTR_HAS_HIGH_BATS,
>> COMMON_PPC,
>> 32, 32,
>> __setup_cpu_603
>> },
>> ....
>> #endif /* CLASSIC_PPC */
>>
>> May be better like this:
>>
>> #if CONFIG_G2_LE
>> { /* All G2_LE (603e core, plus some) have the same pvr */
>> 0x7fff0000, 0x00820000, "G2_LE",
>> CPU_FTR_SPLIT_ID_CACHE | CPU_FTR_CAN_DOZE | CPU_FTR_USE_TB |
>> CPU_FTR_CAN_NAP | CPU_FTR_HAS_HIGH_BATS,
>> COMMON_PPC,
>> 32, 32,
>> __setup_cpu_603
>> },
>> #endif
>>
>> With that move we'll conserve some memory of kernel,
>> but need some explanations which PPCs based on
>> it, for modify Kconfig ( I know MPC52xx and MPC82xx based on it).
--
Best regards,
Andrey Volkov
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c
2004-08-27 11:34 [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c Andrey Volkov
2004-08-27 14:15 ` Kumar Gala
@ 2004-08-27 15:00 ` Dan Malek
2004-08-27 15:16 ` Re[2]: " Andrey Volkov
1 sibling, 1 reply; 6+ messages in thread
From: Dan Malek @ 2004-08-27 15:00 UTC (permalink / raw)
To: Andrey Volkov; +Cc: linuxppc-embedded
On Aug 27, 2004, at 7:34 AM, Andrey Volkov wrote:
> Since G2_LE is NOT a "classic" core ( in particular - true
> little-endian),
How is it not a classic core? It certainly isn't bookE, and it isn't
8xx.
No one should care about little-endian anyway. I'm voting for the
first candidate that makes that illegal. :-)
> With that move we'll conserve some memory of kernel,
How does this single change save anything but a few bytes of
cpu table?
> but need some explanations which PPCs based on
> it, for modify Kconfig ( I know MPC52xx and MPC82xx based on it).
What other kernel changes would you make based on
this configuration?
-- Dan
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re[2]: [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c
2004-08-27 15:00 ` Dan Malek
@ 2004-08-27 15:16 ` Andrey Volkov
2004-08-27 17:49 ` Dan Malek
0 siblings, 1 reply; 6+ messages in thread
From: Andrey Volkov @ 2004-08-27 15:16 UTC (permalink / raw)
To: Dan Malek; +Cc: linuxppc-embedded
Hello Dan,
Friday, August 27, 2004, 7:00:59 PM, you wrote:
>> Since G2_LE is NOT a "classic" core ( in particular - true
>> little-endian),
> How is it not a classic core? It certainly isn't bookE, and it isn't
> 8xx.
> No one should care about little-endian anyway. I'm voting for the
> first candidate that makes that illegal. :-)
Agree.
>> With that move we'll conserve some memory of kernel,
> How does this single change save anything but a few bytes of
> cpu table?
Maybe ~2K of rubbish for somebody "few" - for me not :) (don't forget
its embedded platform).
>> but need some explanations which PPCs based on
>> it, for modify Kconfig ( I know MPC52xx and MPC82xx based on it).
> What other kernel changes would you make based on
> this configuration?
Only Kconfig, nothing more.
--
Best regards,
Andrey Volkov
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Re[2]: [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c
2004-08-27 15:16 ` Re[2]: " Andrey Volkov
@ 2004-08-27 17:49 ` Dan Malek
0 siblings, 0 replies; 6+ messages in thread
From: Dan Malek @ 2004-08-27 17:49 UTC (permalink / raw)
To: Andrey Volkov; +Cc: linuxppc-embedded
On Aug 27, 2004, at 11:16 AM, Andrey Volkov wrote:
> Maybe ~2K of rubbish for somebody "few" - for me not :) (don't forget
> its embedded platform).
If you have a system of this magnitude where a couple of Kbytes is
going to be the difference between success or failure, I'd suggest
looking other places than adding an superfluous #ifdef around
the cpu table.
There are lots of places in the kernel where thorough analysis
and careful configuration will save you lots more than this and
probably make a difference.
-- Dan
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread
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2004-08-27 11:34 [RFC] Remove G2_LE core decl from CLASSIC_PPC part of arch/ppc/kernel/cputable.c Andrey Volkov
2004-08-27 14:15 ` Kumar Gala
2004-08-27 15:00 ` Re[2]: " Andrey Volkov
2004-08-27 15:00 ` Dan Malek
2004-08-27 15:16 ` Re[2]: " Andrey Volkov
2004-08-27 17:49 ` Dan Malek
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