P6_NOPs are definitely not supported on some VIA CPUs, and possibly
(unverified) on AMD K7s. It is also the only thing that prevents a
686 kernel from running on Transmeta TM3x00/5x00 (Crusoe) series.
The performance benefit over generic NOPs is very small, so when
building for generic consumption, avoid using them.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The P6 family of NOPs are only available on family >= 6 or above, so
enforce that in the boot code.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
CONFIG_X86_PPRO_FENCE bloats text:
i386 allmodconf: size mm/built-in.o
text data bss dec hex text ratio
vanilla: 163082 20372 40120 223574 36956 100.00%
bugfix : 163509 20372 40120 224001 36b01 0.26%
noppro : 162191 20372 40120 222683 365db - 0.55%
both : 162267 20372 40120 222759 36627 - 0.50% (+0.05% vs noppro)
So with the ppro memory ordering bug out of the way, the PG_uptodate fix
only adds 76 bytes of text.
allow this config to be specified by distros.
[ mingo@elte.hu: x86.git merge ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
x86: Use def_bool where possible in Kconfig.cpu
Change occurances of:
bool
default X
to:
def_bool X
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This adds the (internal) Kconfig macro CONFIG_X86_DEBUGCTLMSR,
to be defined when configuring to support only hardware that
definitely supports MSR_IA32_DEBUGCTLMSR with the BTF flag.
The Intel documentation says "P6 family" and later processors all have it.
I think the Kconfig dependencies are right to have it set for those and
unset for others (i.e., when 586 and earlier are supported).
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Move all CPU definitions to Kconfig.cpu
Always define X86_MINIMUM_CPU_FAMILY and do the
obvious code cleanup in boot/cpucheck.c
Comments from: Adrian Bunk <bunk@kernel.org> incorporated.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Brian Gerst <bgerst@didntduck.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
