[PATCH 03/12] x86 Kconfig: move highmem

From: Dave Hansen
Date: Mon Dec 30 2013 - 13:41:26 EST



From: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>

This just continues to move things under the Memory and NUMA
Options menu, breaking it up a bit to make the patches easier to
audit.

Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
---

linux.git-davehans/arch/x86/Kconfig | 248 ++++++++++++++++++------------------
1 file changed, 124 insertions(+), 124 deletions(-)

diff -puN arch/x86/Kconfig~x86-config-move-highmem arch/x86/Kconfig
--- linux.git/arch/x86/Kconfig~x86-config-move-highmem 2013-12-30 10:37:44.258190443 -0800
+++ linux.git-davehans/arch/x86/Kconfig 2013-12-30 10:37:44.263190667 -0800
@@ -687,6 +687,130 @@ config X86_SUPPORTS_MEMORY_FAILURE
depends on X86_64 || !SPARSEMEM
select ARCH_SUPPORTS_MEMORY_FAILURE

+choice
+ prompt "High Memory Support"
+ default HIGHMEM64G if X86_NUMAQ
+ default HIGHMEM4G
+ depends on X86_32
+
+config NOHIGHMEM
+ bool "off"
+ depends on !X86_NUMAQ
+ ---help---
+ Linux can use up to 64 Gigabytes of physical memory on x86 systems.
+ However, the address space of 32-bit x86 processors is only 4
+ Gigabytes large. That means that, if you have a large amount of
+ physical memory, not all of it can be "permanently mapped" by the
+ kernel. The physical memory that's not permanently mapped is called
+ "high memory".
+
+ If you are compiling a kernel which will never run on a machine with
+ more than 1 Gigabyte total physical RAM, answer "off" here (default
+ choice and suitable for most users). This will result in a "3GB/1GB"
+ split: 3GB are mapped so that each process sees a 3GB virtual memory
+ space and the remaining part of the 4GB virtual memory space is used
+ by the kernel to permanently map as much physical memory as
+ possible.
+
+ If the machine has between 1 and 4 Gigabytes physical RAM, then
+ answer "4GB" here.
+
+ If more than 4 Gigabytes is used then answer "64GB" here. This
+ selection turns Intel PAE (Physical Address Extension) mode on.
+ PAE implements 3-level paging on IA32 processors. PAE is fully
+ supported by Linux, PAE mode is implemented on all recent Intel
+ processors (Pentium Pro and better). NOTE: If you say "64GB" here,
+ then the kernel will not boot on CPUs that don't support PAE!
+
+ The actual amount of total physical memory will either be
+ auto detected or can be forced by using a kernel command line option
+ such as "mem=256M". (Try "man bootparam" or see the documentation of
+ your boot loader (lilo or loadlin) about how to pass options to the
+ kernel at boot time.)
+
+ If unsure, say "off".
+
+config HIGHMEM4G
+ bool "4GB"
+ depends on !X86_NUMAQ
+ ---help---
+ Select this if you have a 32-bit processor and between 1 and 4
+ gigabytes of physical RAM.
+
+config HIGHMEM64G
+ bool "64GB"
+ depends on !M486
+ select X86_PAE
+ ---help---
+ Select this if you have a 32-bit processor and more than 4
+ gigabytes of physical RAM.
+
+endchoice
+
+choice
+ prompt "Memory split" if EXPERT
+ default VMSPLIT_3G
+ depends on X86_32
+ ---help---
+ Select the desired split between kernel and user memory.
+
+ If the address range available to the kernel is less than the
+ physical memory installed, the remaining memory will be available
+ as "high memory". Accessing high memory is a little more costly
+ than low memory, as it needs to be mapped into the kernel first.
+ Note that increasing the kernel address space limits the range
+ available to user programs, making the address space there
+ tighter. Selecting anything other than the default 3G/1G split
+ will also likely make your kernel incompatible with binary-only
+ kernel modules.
+
+ If you are not absolutely sure what you are doing, leave this
+ option alone!
+
+ config VMSPLIT_3G
+ bool "3G/1G user/kernel split"
+ config VMSPLIT_3G_OPT
+ depends on !X86_PAE
+ bool "3G/1G user/kernel split (for full 1G low memory)"
+ config VMSPLIT_2G
+ bool "2G/2G user/kernel split"
+ config VMSPLIT_2G_OPT
+ depends on !X86_PAE
+ bool "2G/2G user/kernel split (for full 2G low memory)"
+ config VMSPLIT_1G
+ bool "1G/3G user/kernel split"
+endchoice
+
+config PAGE_OFFSET
+ hex
+ default 0xB0000000 if VMSPLIT_3G_OPT
+ default 0x80000000 if VMSPLIT_2G
+ default 0x78000000 if VMSPLIT_2G_OPT
+ default 0x40000000 if VMSPLIT_1G
+ default 0xC0000000
+ depends on X86_32
+
+config HIGHMEM
+ def_bool y
+ depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
+
+config X86_PAE
+ bool "PAE (Physical Address Extension) Support"
+ depends on X86_32 && !HIGHMEM4G
+ ---help---
+ PAE is required for NX support, and furthermore enables
+ larger swapspace support for non-overcommit purposes. It
+ has the cost of more pagetable lookup overhead, and also
+ consumes more pagetable space per process.
+
+config ARCH_PHYS_ADDR_T_64BIT
+ def_bool y
+ depends on X86_64 || X86_PAE
+
+config ARCH_DMA_ADDR_T_64BIT
+ def_bool y
+ depends on X86_64 || HIGHMEM64G
+
endmenu # Memory and NUMA Options

if X86_WANT_INTEL_MID
@@ -1315,130 +1439,6 @@ config X86_CPUID
with major 203 and minors 0 to 31 for /dev/cpu/0/cpuid to
/dev/cpu/31/cpuid.

-choice
- prompt "High Memory Support"
- default HIGHMEM64G if X86_NUMAQ
- default HIGHMEM4G
- depends on X86_32
-
-config NOHIGHMEM
- bool "off"
- depends on !X86_NUMAQ
- ---help---
- Linux can use up to 64 Gigabytes of physical memory on x86 systems.
- However, the address space of 32-bit x86 processors is only 4
- Gigabytes large. That means that, if you have a large amount of
- physical memory, not all of it can be "permanently mapped" by the
- kernel. The physical memory that's not permanently mapped is called
- "high memory".
-
- If you are compiling a kernel which will never run on a machine with
- more than 1 Gigabyte total physical RAM, answer "off" here (default
- choice and suitable for most users). This will result in a "3GB/1GB"
- split: 3GB are mapped so that each process sees a 3GB virtual memory
- space and the remaining part of the 4GB virtual memory space is used
- by the kernel to permanently map as much physical memory as
- possible.
-
- If the machine has between 1 and 4 Gigabytes physical RAM, then
- answer "4GB" here.
-
- If more than 4 Gigabytes is used then answer "64GB" here. This
- selection turns Intel PAE (Physical Address Extension) mode on.
- PAE implements 3-level paging on IA32 processors. PAE is fully
- supported by Linux, PAE mode is implemented on all recent Intel
- processors (Pentium Pro and better). NOTE: If you say "64GB" here,
- then the kernel will not boot on CPUs that don't support PAE!
-
- The actual amount of total physical memory will either be
- auto detected or can be forced by using a kernel command line option
- such as "mem=256M". (Try "man bootparam" or see the documentation of
- your boot loader (lilo or loadlin) about how to pass options to the
- kernel at boot time.)
-
- If unsure, say "off".
-
-config HIGHMEM4G
- bool "4GB"
- depends on !X86_NUMAQ
- ---help---
- Select this if you have a 32-bit processor and between 1 and 4
- gigabytes of physical RAM.
-
-config HIGHMEM64G
- bool "64GB"
- depends on !M486
- select X86_PAE
- ---help---
- Select this if you have a 32-bit processor and more than 4
- gigabytes of physical RAM.
-
-endchoice
-
-choice
- prompt "Memory split" if EXPERT
- default VMSPLIT_3G
- depends on X86_32
- ---help---
- Select the desired split between kernel and user memory.
-
- If the address range available to the kernel is less than the
- physical memory installed, the remaining memory will be available
- as "high memory". Accessing high memory is a little more costly
- than low memory, as it needs to be mapped into the kernel first.
- Note that increasing the kernel address space limits the range
- available to user programs, making the address space there
- tighter. Selecting anything other than the default 3G/1G split
- will also likely make your kernel incompatible with binary-only
- kernel modules.
-
- If you are not absolutely sure what you are doing, leave this
- option alone!
-
- config VMSPLIT_3G
- bool "3G/1G user/kernel split"
- config VMSPLIT_3G_OPT
- depends on !X86_PAE
- bool "3G/1G user/kernel split (for full 1G low memory)"
- config VMSPLIT_2G
- bool "2G/2G user/kernel split"
- config VMSPLIT_2G_OPT
- depends on !X86_PAE
- bool "2G/2G user/kernel split (for full 2G low memory)"
- config VMSPLIT_1G
- bool "1G/3G user/kernel split"
-endchoice
-
-config PAGE_OFFSET
- hex
- default 0xB0000000 if VMSPLIT_3G_OPT
- default 0x80000000 if VMSPLIT_2G
- default 0x78000000 if VMSPLIT_2G_OPT
- default 0x40000000 if VMSPLIT_1G
- default 0xC0000000
- depends on X86_32
-
-config HIGHMEM
- def_bool y
- depends on X86_32 && (HIGHMEM64G || HIGHMEM4G)
-
-config X86_PAE
- bool "PAE (Physical Address Extension) Support"
- depends on X86_32 && !HIGHMEM4G
- ---help---
- PAE is required for NX support, and furthermore enables
- larger swapspace support for non-overcommit purposes. It
- has the cost of more pagetable lookup overhead, and also
- consumes more pagetable space per process.
-
-config ARCH_PHYS_ADDR_T_64BIT
- def_bool y
- depends on X86_64 || X86_PAE
-
-config ARCH_DMA_ADDR_T_64BIT
- def_bool y
- depends on X86_64 || HIGHMEM64G
-
config MATH_EMULATION
bool
prompt "Math emulation" if X86_32
_
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