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authorDave Airlie <airlied@redhat.com>2014-01-20 10:21:54 +1000
committerDave Airlie <airlied@redhat.com>2014-01-20 10:21:54 +1000
commitcfd72a4c2089aa3938f37281a34d6eb3306d5fd8 (patch)
treee63f6df423aeb59d1ea5f7af3597d6718e75c335 /arch/x86/include/asm/preempt.h
parent9354eafd893f45320a37da360e1728104e49cc2f (diff)
parent0d9d349d8788d30f3fc3bb39279c370f94d9dbec (diff)
Merge branch 'drm-intel-next' of git://people.freedesktop.org/~danvet/drm-intel into drm-next
drm-intel-next-2014-01-10: - final bits for runtime D3 on Haswell from Paul (now enabled fully) - parse the backlight modulation freq information in the VBT from Jani (but not yet used) - more watermark improvements from Ville for ilk-ivb and bdw - bugfixes for fastboot from Jesse - watermark fix for i830M (but not yet everything) - vlv vga hotplug w/a (Imre) - piles of other small improvements, cleanups and fixes all over Note that the pull request includes a backmerge of the last drm-fixes pulled into Linus' tree - things where getting a bit too messy. So the shortlog also contains a bunch of patches from Linus tree. Please yell if you want me to frob it for you a bit. * 'drm-intel-next' of git://people.freedesktop.org/~danvet/drm-intel: (609 commits) drm/i915/bdw: make sure south port interrupts are enabled properly v2 drm/i915: Include more information in disabled hotplug interrupt warning drm/i915: Only complain about a rogue hotplug IRQ after disabling drm/i915: Only WARN about a stuck hotplug irq ONCE drm/i915: s/hotplugt_status_gen4/hotplug_status_g4x/
Diffstat (limited to 'arch/x86/include/asm/preempt.h')
-rw-r--r--arch/x86/include/asm/preempt.h11
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h
index 8729723636fd..c8b051933b1b 100644
--- a/arch/x86/include/asm/preempt.h
+++ b/arch/x86/include/asm/preempt.h
@@ -8,6 +8,12 @@
DECLARE_PER_CPU(int, __preempt_count);
/*
+ * We use the PREEMPT_NEED_RESCHED bit as an inverted NEED_RESCHED such
+ * that a decrement hitting 0 means we can and should reschedule.
+ */
+#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED)
+
+/*
* We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users
* that think a non-zero value indicates we cannot preempt.
*/
@@ -74,6 +80,11 @@ static __always_inline void __preempt_count_sub(int val)
__this_cpu_add_4(__preempt_count, -val);
}
+/*
+ * Because we keep PREEMPT_NEED_RESCHED set when we do _not_ need to reschedule
+ * a decrement which hits zero means we have no preempt_count and should
+ * reschedule.
+ */
static __always_inline bool __preempt_count_dec_and_test(void)
{
GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e");