This patch adds some configuration options that allow to compile out
CPU vendor-specific code in x86 kernels (in arch/x86/kernel/cpu). The
new configuration options are only visible when CONFIG_EMBEDDED is
selected, as they are mostly interesting for space savings reasons.
An example of size saving, on x86 with only Intel CPU support:
text data bss dec hex filename
1125479 118760 212992 1457231 163c4f vmlinux.old
1121355 116536 212992 1450883 162383 vmlinux
-4124 -2224 0 -6348 -18CC +/-
However, I'm not exactly sure that the Kconfig wording is correct with
regard to !64BIT / 64BIT.
Signed-off-by: Thomas Petazzoni <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
---
arch/x86/Kconfig.cpu | 70 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/Makefile | 19 ++++++-----
include/asm-x86/bugs.h | 5 +++
3 files changed, 85 insertions(+), 9 deletions(-)
diff --git a/arch/x86/Kconfig.cpu b/arch/x86/Kconfig.cpu
index 2c518fb..6156ac2 100644
--- a/arch/x86/Kconfig.cpu
+++ b/arch/x86/Kconfig.cpu
@@ -415,3 +415,73 @@ config X86_MINIMUM_CPU_FAMILY
config X86_DEBUGCTLMSR
def_bool y
depends on !(MK6 || MWINCHIPC6 || MWINCHIP2 || MWINCHIP3D || MCYRIXIII || M586MMX || M586TSC || M586 || M486 || M386)
+
+menuconfig PROCESSOR_SELECT
+ default y
+ bool "Supported processor vendors" if EMBEDDED
+ help
+ This lets you choose what x86 vendor support code your kernel
+ will include.
+
+config CPU_SUP_INTEL_32
+ default y
+ bool "Support Intel processors" if PROCESSOR_SELECT
+ depends on !64BIT
+ help
+ This enables extended support for Intel processors
+
+config CPU_SUP_INTEL_64
+ default y
+ bool "Support Intel processors" if PROCESSOR_SELECT
+ depends on 64BIT
+ help
+ This enables extended support for Intel processors
+
+config CPU_SUP_CYRIX_32
+ default y
+ bool "Support Cyrix processors" if PROCESSOR_SELECT
+ depends on !64BIT
+ help
+ This enables extended support for Cyrix processors
+
+config CPU_SUP_AMD_32
+ default y
+ bool "Support AMD processors" if PROCESSOR_SELECT
+ depends on !64BIT
+ help
+ This enables extended support for AMD processors
+
+config CPU_SUP_AMD_64
+ default y
+ bool "Support AMD processors" if PROCESSOR_SELECT
+ depends on 64BIT
+ help
+ This enables extended support for AMD processors
+
+config CPU_SUP_CENTAUR_32
+ default y
+ bool "Support Centaur processors" if PROCESSOR_SELECT
+ depends on !64BIT
+ help
+ This enables extended support for Centaur processors
+
+config CPU_SUP_CENTAUR_64
+ default y
+ bool "Support Centaur processors" if PROCESSOR_SELECT
+ depends on 64BIT
+ help
+ This enables extended support for Centaur processors
+
+config CPU_SUP_TRANSMETA_32
+ default y
+ bool "Support Transmeta processors" if PROCESSOR_SELECT
+ depends on !64BIT
+ help
+ This enables extended support for Transmeta processors
+
+config CPU_SUP_UMC_32
+ default y
+ bool "Support UMC processors" if PROCESSOR_SELECT
+ depends on !64BIT
+ help
+ This enables extended support for UMC processors
diff --git a/arch/x86/kernel/cpu/Makefile b/arch/x86/kernel/cpu/Makefile
index ee76eaa..a35ee92 100644
--- a/arch/x86/kernel/cpu/Makefile
+++ b/arch/x86/kernel/cpu/Makefile
@@ -7,15 +7,16 @@ obj-y += proc.o feature_names.o
obj-$(CONFIG_X86_32) += common.o bugs.o
obj-$(CONFIG_X86_64) += common_64.o bugs_64.o
-obj-$(CONFIG_X86_32) += amd.o
-obj-$(CONFIG_X86_64) += amd_64.o
-obj-$(CONFIG_X86_32) += cyrix.o
-obj-$(CONFIG_X86_32) += centaur.o
-obj-$(CONFIG_X86_64) += centaur_64.o
-obj-$(CONFIG_X86_32) += transmeta.o
-obj-$(CONFIG_X86_32) += intel.o
-obj-$(CONFIG_X86_64) += intel_64.o
-obj-$(CONFIG_X86_32) += umc.o
+
+obj-$(CONFIG_CPU_SUP_AMD_32) += amd.o
+obj-$(CONFIG_CPU_SUP_AMD_64) += amd_64.o
+obj-$(CONFIG_CPU_SUP_CYRIX_32) += cyrix.o
+obj-$(CONFIG_CPU_SUP_CENTAUR_32) += centaur.o
+obj-$(CONFIG_CPU_SUP_CENTAUR_64) += centaur_64.o
+obj-$(CONFIG_CPU_SUP_TRANSMETA_32) += transmeta.o
+obj-$(CONFIG_CPU_SUP_INTEL_32) += intel.o
+obj-$(CONFIG_CPU_SUP_INTEL_64) += intel_64.o
+obj-$(CONFIG_CPU_SUP_UMC_32) += umc.o
obj-$(CONFIG_X86_MCE) += mcheck/
obj-$(CONFIG_MTRR) += mtrr/
diff --git a/include/asm-x86/bugs.h b/include/asm-x86/bugs.h
index 021cbdd..66cf8c9 100644
--- a/include/asm-x86/bugs.h
+++ b/include/asm-x86/bugs.h
@@ -2,6 +2,11 @@
#define _ASM_X86_BUGS_H
extern void check_bugs(void);
+
+#ifdef CONFIG_CPU_SUP_INTEL_32
int ppro_with_ram_bug(void);
+#else
+#define ppro_with_ram_bug() (0)
+#endif
#endif /* _ASM_X86_BUGS_H */
--
1.5.4.3
Thomas Petazzoni <[email protected]> wrote:
> This patch adds some configuration options that allow to compile out
> CPU vendor-specific code in x86 kernels (in arch/x86/kernel/cpu). The
> new configuration options are only visible when CONFIG_EMBEDDED is
> selected, as they are mostly interesting for space savings reasons.
> +menuconfig PROCESSOR_SELECT
> + default y
> + bool "Supported processor vendors" if EMBEDDED
> + help
> + This lets you choose what x86 vendor support code your kernel
> + will include.
> +
> +config CPU_SUP_INTEL_32
> + default y
> + bool "Support Intel processors" if PROCESSOR_SELECT
> + depends on !64BIT
> + help
> + This enables extended support for Intel processors
> +
I don't think having a generic kernel for only Intel CPUs makes much sense,
and OTOH, if you optimize for e.g. Athlon CPUs, you're likely to not need
Intel code on that machine - even on desktop systems.
What about an option to "Include code for CPUs from all supported vendors",
invisible and y for generic kernels?
* Thomas Petazzoni <[email protected]> wrote:
> This patch adds some configuration options that allow to compile out
> CPU vendor-specific code in x86 kernels (in arch/x86/kernel/cpu). The
> new configuration options are only visible when CONFIG_EMBEDDED is
> selected, as they are mostly interesting for space savings reasons.
>
> An example of size saving, on x86 with only Intel CPU support:
>
> text data bss dec hex filename
> 1125479 118760 212992 1457231 163c4f vmlinux.old
> 1121355 116536 212992 1450883 162383 vmlinux
> -4124 -2224 0 -6348 -18CC +/-
>
> However, I'm not exactly sure that the Kconfig wording is correct with
> regard to !64BIT / 64BIT.
applied to tip/x86/cpu, thanks Thomas. (I've done a trivial cleanup:
converted the macro to an inline.)
Peter, do you like this version of the patch or would you like further
improvements?
Ingo
-tip testing found a couple of build failures:
LD .tmp_vmlinux1
arch/x86/lib/lib.a(usercopy_32.o): In function `__copy_to_user_ll':
(.text+0x11e): undefined reference to `movsl_mask'
arch/x86/lib/lib.a(usercopy_32.o): In function `__copy_from_user_ll':
(.text+0x1fa): undefined reference to `movsl_mask'
arch/x86/lib/lib.a(usercopy_32.o): In function
`__copy_from_user_ll_nozero':
(.text+0x2d6): undefined reference to `movsl_mask'
arch/x86/lib/lib.a(usercopy_32.o): In function `copy_from_user':
(.text+0x5ac): undefined reference to `movsl_mask'
arch/x86/lib/lib.a(usercopy_32.o): In function `copy_to_user':
(.text+0x6bf): undefined reference to `movsl_mask'
make: *** [.tmp_vmlinux1] Error 1
with:
http://redhat.com/~mingo/misc/config-Fri_Aug_15_16_35_03_CEST_2008.bad
and:
arch/x86/kvm/built-in.o: In function `paging64_cmpxchg_gpte':
mmu.c:(.text+0xa80d): undefined reference to `cmpxchg_486_u64'
with:
http://redhat.com/~mingo/misc/config-Fri_Aug_15_16_27_47_CEST_2008.bad
reverting your change solved both of them.
i still have the commit in tip/x86/cpu so please send a delta fix ontop
of your previous patch once you figure out the problem. Thanks,
Ingo
Ingo Molnar wrote:
> * Thomas Petazzoni <[email protected]> wrote:
>
>> This patch adds some configuration options that allow to compile out
>> CPU vendor-specific code in x86 kernels (in arch/x86/kernel/cpu). The
>> new configuration options are only visible when CONFIG_EMBEDDED is
>> selected, as they are mostly interesting for space savings reasons.
>>
>> An example of size saving, on x86 with only Intel CPU support:
>>
>> text data bss dec hex filename
>> 1125479 118760 212992 1457231 163c4f vmlinux.old
>> 1121355 116536 212992 1450883 162383 vmlinux
>> -4124 -2224 0 -6348 -18CC +/-
>>
>> However, I'm not exactly sure that the Kconfig wording is correct with
>> regard to !64BIT / 64BIT.
>
> applied to tip/x86/cpu, thanks Thomas. (I've done a trivial cleanup:
> converted the macro to an inline.)
>
> Peter, do you like this version of the patch or would you like further
> improvements?
>
I'm fine with it.
I think there might still be cross-dependencies, but it doesn't break
anything old, so we can deal with that via bug reports.
The other thing that probably should be done is breaking out the
Intel-specific versus generic parts of intel_cacheinfo.c.
-hpa