x86/Kconfig: Simplify NR_CPUS config

Clean up and simplify the X86 NR_CPUS Kconfig symbol/option by
introducing RANGE_BEGIN_CPUS, RANGE_END_CPUS, and DEF_CONFIG_CPUS.
Then combine some default values when their conditionals can be
reduced.

Also move the X86_BIGSMP kconfig option inside an "if X86_32"/"endif"
config block and drop its explicit "depends on X86_32".

Combine the max. 8192 cases of RANGE_END_CPUS (X86_64 only).
Split RANGE_END_CPUS and DEF_CONFIG_CPUS into separate cases for
X86_32 and X86_64.

Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/0b833246-ed4b-e451-c426-c4464725be92@infradead.org
Link: lkml.kernel.org/r/CA+55aFzOd3j6ZUSkEwTdk85qtt1JywOtm3ZAb-qAvt8_hJ6D4A@mail.gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 63bf349b2b24a8807c4f65869af50bab99e4c2f7..9d921b78b1453f2d606063301cb5e3f2dac8d9e9 100644 (file)
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -423,12 +423,6 @@ config X86_MPPARSE
          For old smp systems that do not have proper acpi support. Newer systems
          (esp with 64bit cpus) with acpi support, MADT and DSDT will override it
 
-config X86_BIGSMP
-       bool "Support for big SMP systems with more than 8 CPUs"
-       depends on X86_32 && SMP
-       ---help---
-         This option is needed for the systems that have more than 8 CPUs
-
 config GOLDFISH
        def_bool y
        depends on X86_GOLDFISH
@@ -460,6 +454,12 @@ config INTEL_RDT
          Say N if unsure.
 
 if X86_32
+config X86_BIGSMP
+       bool "Support for big SMP systems with more than 8 CPUs"
+       depends on SMP
+       ---help---
+         This option is needed for the systems that have more than 8 CPUs
+
 config X86_EXTENDED_PLATFORM
        bool "Support for extended (non-PC) x86 platforms"
        default y
@@ -949,17 +949,44 @@ config MAXSMP
          Enable maximum number of CPUS and NUMA Nodes for this architecture.
          If unsure, say N.
 
+config RANGE_END_CPUS
+       int
+       depends on X86_32
+       default 8 if SMP && !X86_BIGSMP
+       default 64 if SMP && X86_BIGSMP
+       default 1 if !SMP
+
+config RANGE_END_CPUS
+       int
+       depends on X86_64
+       default 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK
+       default 8192 if SMP && (MAXSMP || CPUMASK_OFFSTACK)
+       default 1 if !SMP
+
+config RANGE_BEGIN_CPUS
+       int
+       default 1 if !SMP
+       default RANGE_END_CPUS if MAXSMP
+       default 2
+
+config DEF_CONFIG_CPUS
+       int
+       depends on X86_32
+       default 1 if !SMP
+       default 32 if X86_BIGSMP
+       default 8 if SMP
+
+config DEF_CONFIG_CPUS
+       int
+       depends on X86_64
+       default 1 if !SMP
+       default 8192 if MAXSMP
+       default 64 if SMP
+
 config NR_CPUS
        int "Maximum number of CPUs" if SMP && !MAXSMP
-       range 2 8 if SMP && X86_32 && !X86_BIGSMP
-       range 2 64 if SMP && X86_32 && X86_BIGSMP
-       range 2 512 if SMP && !MAXSMP && !CPUMASK_OFFSTACK && X86_64
-       range 2 8192 if SMP && !MAXSMP && CPUMASK_OFFSTACK && X86_64
-       default "1" if !SMP
-       default "8192" if MAXSMP
-       default "32" if SMP && X86_BIGSMP
-       default "8" if SMP && X86_32
-       default "64" if SMP
+       range RANGE_BEGIN_CPUS RANGE_END_CPUS
+       default DEF_CONFIG_CPUS
        ---help---
          This allows you to specify the maximum number of CPUs which this
          kernel will support.  If CPUMASK_OFFSTACK is enabled, the maximum