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authorLuis R. Rodriguez <mcgrof@suse.com>2015-03-04 17:24:12 -0800
committerIngo Molnar <mingo@kernel.org>2015-03-05 08:02:12 +0100
commite5008abe929c160d36e44b8c2b644d4330d2e389 (patch)
tree615a41d918d9ce3c623716925b0d25a1fb543d65 /arch/x86/mm/init.c
parentd9fd579c218e22c897f0f1b9e132af9b436cf445 (diff)
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.c17
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