diff options
| author | Luis R. Rodriguez <mcgrof@suse.com> | 2015-03-05 04:24:12 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-03-05 10:02:12 +0300 |
| commit | e5008abe929c160d36e44b8c2b644d4330d2e389 (patch) | |
| tree | 615a41d918d9ce3c623716925b0d25a1fb543d65 /arch/x86/mm/init.c | |
| parent | d9fd579c218e22c897f0f1b9e132af9b436cf445 (diff) | |
| download | linux-e5008abe929c160d36e44b8c2b644d4330d2e389.tar.xz | |
x86/mm: Simplify enabling direct_gbpages
direct_gbpages can be force enabled as an early parameter
but not really have taken effect when DEBUG_PAGEALLOC
or KMEMCHECK is enabled. You can also enable direct_gbpages
right now if you have an x86_64 architecture but your CPU
doesn't really have support for this feature. In both cases
PG_LEVEL_1G won't actually be enabled but direct_gbpages is used
in other areas under the assumptions that PG_LEVEL_1G
was set. Fix this by putting together all requirements
which make this feature sensible to enable under, and only
enable both finally flipping on PG_LEVEL_1G and leaving
PG_LEVEL_1G set when this is true.
We only enable this feature then to be possible on sensible
builds defined by the new ENABLE_DIRECT_GBPAGES. If the
CPU has support for it you can either enable this by using
the DIRECT_GBPAGES option or using the early kernel parameter.
If a platform had support for this you can always force disable
it as well.
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: JBeulich@suse.com
Cc: Jan Beulich <JBeulich@suse.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: julia.lawall@lip6.fr
Link: http://lkml.kernel.org/r/1425518654-3403-3-git-send-email-mcgrof@do-not-panic.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm/init.c')
| -rw-r--r-- | arch/x86/mm/init.c | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c index 74f2b37fd073..2ce2c8e8c99c 100644 --- a/arch/x86/mm/init.c +++ b/arch/x86/mm/init.c @@ -131,16 +131,21 @@ void __init early_alloc_pgt_buf(void) int after_bootmem; +static int page_size_mask; + int direct_gbpages = IS_ENABLED(CONFIG_DIRECT_GBPAGES); static void __init init_gbpages(void) { -#ifdef CONFIG_X86_64 - if (direct_gbpages && cpu_has_gbpages) + if (!IS_ENABLED(CONFIG_ENABLE_DIRECT_GBPAGES)) { + direct_gbpages = 0; + return; + } + if (direct_gbpages && cpu_has_gbpages) { printk(KERN_INFO "Using GB pages for direct mapping\n"); - else + page_size_mask |= 1 << PG_LEVEL_1G; + } else direct_gbpages = 0; -#endif } struct map_range { @@ -149,8 +154,6 @@ struct map_range { unsigned page_size_mask; }; -static int page_size_mask; - static void __init probe_page_size_mask(void) { init_gbpages(); @@ -161,8 +164,6 @@ static void __init probe_page_size_mask(void) * This will simplify cpa(), which otherwise needs to support splitting * large pages into small in interrupt context, etc. */ - if (direct_gbpages) - page_size_mask |= 1 << PG_LEVEL_1G; if (cpu_has_pse) page_size_mask |= 1 << PG_LEVEL_2M; #endif |