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authorToshi Kani <toshi.kani@hp.com>2015-04-14 15:47:20 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-14 16:49:04 -0700
commit0ddab1d2ed664c85c95488eef569786a84aedf37 (patch)
treeb7f2d24f5ba9e307052833500758e0d7bf10bf53 /Documentation
parent0f616be120c632c818faaea9adcb8f05a7a8601f (diff)
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')
-rw-r--r--Documentation/kernel-parameters.txt2
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.