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| author | Toshi Kani <toshi.kani@hp.com> | 2015-04-14 15:47:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 16:49:04 -0700 |
| commit | 0ddab1d2ed664c85c95488eef569786a84aedf37 (patch) | |
| tree | b7f2d24f5ba9e307052833500758e0d7bf10bf53 /Documentation/kernel-parameters.txt | |
| parent | 0f616be120c632c818faaea9adcb8f05a7a8601f (diff) | |
| download | lwn-0ddab1d2ed664c85c95488eef569786a84aedf37.tar.gz lwn-0ddab1d2ed664c85c95488eef569786a84aedf37.zip | |
lib/ioremap.c: add huge I/O map capability interfaces
Add ioremap_pud_enabled() and ioremap_pmd_enabled(), which return 1 when
I/O mappings with pud/pmd are enabled on the kernel.
ioremap_huge_init() calls arch_ioremap_pud_supported() and
arch_ioremap_pmd_supported() to initialize the capabilities at boot-time.
A new kernel option "nohugeiomap" is also added, so that user can disable
the huge I/O map capabilities when necessary.
Signed-off-by: Toshi Kani <toshi.kani@hp.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Robert Elliott <Elliott@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 71eecb263250..b1fa70907ccf 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -2323,6 +2323,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. register save and restore. The kernel will only save legacy floating-point registers on task switch. + nohugeiomap [KNL,x86] Disable kernel huge I/O mappings. + noxsave [BUGS=X86] Disables x86 extended register state save and restore using xsave. The kernel will fallback to enabling legacy floating-point and sse state. |