sched/preempt: Merge preempt_mask.h into preempt.h

preempt_mask.h defines all the preempt_count semantics and related
symbols: preempt, softirq, hardirq, nmi, preempt active, need resched,
etc...

preempt.h defines the accessors and mutators of preempt_count.

But there is a messy dependency game around those two header files:

	* preempt_mask.h includes preempt.h in order to access preempt_count()

	* preempt_mask.h defines all preempt_count semantic and symbols
	  except PREEMPT_NEED_RESCHED that is needed by asm/preempt.h
	  Thus we need to define it from preempt.h, right before including
	  asm/preempt.h, instead of defining it to preempt_mask.h with the
	  other preempt_count symbols. Therefore the preempt_count semantics
	  happen to be spread out.

	* We plan to introduce preempt_active_[enter,exit]() to consolidate
	  preempt_schedule*() code. But we'll need to access both preempt_count
	  mutators (preempt_count_add()) and preempt_count symbols
	  (PREEMPT_ACTIVE, PREEMPT_OFFSET). The usual place to define preempt
	  operations is in preempt.h but then we'll need symbols in
	  preempt_mask.h which already includes preempt.h. So we end up with
	  a ressource circle dependency.

Lets merge preempt_mask.h into preempt.h to solve these dependency issues.
This way we gather semantic symbols and operation definition of
preempt_count in a single file.

This is a dumb copy-paste merge. Further merge re-arrangments are
performed in a subsequent patch to ease review.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431441711-29753-2-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/m68k/include/asm/irqflags.h b/arch/m68k/include/asm/irqflags.h
index a823cd73dc09e35bdfe683ab0637dd3c19ffdcb1..b5941818346f65dfbaad65823d2e61a59673f44a 100644 (file)
--- a/arch/m68k/include/asm/irqflags.h
+++ b/arch/m68k/include/asm/irqflags.h
@@ -2,9 +2,6 @@
 #define _M68K_IRQFLAGS_H
 
 #include <linux/types.h>
-#ifdef CONFIG_MMU
-#include <linux/preempt_mask.h>
-#endif
 #include <linux/preempt.h>
 #include <asm/thread_info.h>
 #include <asm/entry.h>

diff --git a/include/linux/bottom_half.h b/include/linux/bottom_half.h
index 86c12c93e3cf6ce9c1db4085b9ee986d2c1e5b9a..8fdcb783197d723a60dc548114af08cd6de9ca88 100644 (file)
--- a/include/linux/bottom_half.h
+++ b/include/linux/bottom_half.h
@@ -2,7 +2,6 @@
 #define _LINUX_BH_H
 
 #include <linux/preempt.h>
-#include <linux/preempt_mask.h>
 
 #ifdef CONFIG_TRACE_IRQFLAGS
 extern void __local_bh_disable_ip(unsigned long ip, unsigned int cnt);

diff --git a/include/linux/hardirq.h b/include/linux/hardirq.h
index f4af03404b9789805e06638303a8873aa14fe5a8..dfd59d6bc6f0f74ef89b0512a25180fd0077e2d3 100644 (file)
--- a/include/linux/hardirq.h
+++ b/include/linux/hardirq.h
@@ -1,7 +1,7 @@
 #ifndef LINUX_HARDIRQ_H
 #define LINUX_HARDIRQ_H
 
-#include <linux/preempt_mask.h>
+#include <linux/preempt.h>
 #include <linux/lockdep.h>
 #include <linux/ftrace_irq.h>
 #include <linux/vtime.h>

diff --git a/include/linux/preempt.h b/include/linux/preempt.h
index de83b4eb164287db363328f87c0f8af216497a91..8cc0338a5e9a5252af1ab48e4d5d6df34943f0cf 100644 (file)
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -17,6 +17,117 @@
 
 #include <asm/preempt.h>
 
+/*
+ * We put the hardirq and softirq counter into the preemption
+ * counter. The bitmask has the following meaning:
+ *
+ * - bits 0-7 are the preemption count (max preemption depth: 256)
+ * - bits 8-15 are the softirq count (max # of softirqs: 256)
+ *
+ * The hardirq count could in theory be the same as the number of
+ * interrupts in the system, but we run all interrupt handlers with
+ * interrupts disabled, so we cannot have nesting interrupts. Though
+ * there are a few palaeontologic drivers which reenable interrupts in
+ * the handler, so we need more than one bit here.
+ *
+ * PREEMPT_MASK:       0x000000ff
+ * SOFTIRQ_MASK:       0x0000ff00
+ * HARDIRQ_MASK:       0x000f0000
+ *     NMI_MASK:       0x00100000
+ * PREEMPT_ACTIVE:     0x00200000
+ */
+#define PREEMPT_BITS   8
+#define SOFTIRQ_BITS   8
+#define HARDIRQ_BITS   4
+#define NMI_BITS       1
+
+#define PREEMPT_SHIFT  0
+#define SOFTIRQ_SHIFT  (PREEMPT_SHIFT + PREEMPT_BITS)
+#define HARDIRQ_SHIFT  (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
+#define NMI_SHIFT      (HARDIRQ_SHIFT + HARDIRQ_BITS)
+
+#define __IRQ_MASK(x)  ((1UL << (x))-1)
+
+#define PREEMPT_MASK   (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
+#define SOFTIRQ_MASK   (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
+#define HARDIRQ_MASK   (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
+#define NMI_MASK       (__IRQ_MASK(NMI_BITS)     << NMI_SHIFT)
+
+#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
+#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
+#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
+#define NMI_OFFSET     (1UL << NMI_SHIFT)
+
+#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
+
+#define PREEMPT_ACTIVE_BITS    1
+#define PREEMPT_ACTIVE_SHIFT   (NMI_SHIFT + NMI_BITS)
+#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
+
+#define hardirq_count()        (preempt_count() & HARDIRQ_MASK)
+#define softirq_count()        (preempt_count() & SOFTIRQ_MASK)
+#define irq_count()    (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
+                                | NMI_MASK))
+
+/*
+ * Are we doing bottom half or hardware interrupt processing?
+ * Are we in a softirq context? Interrupt context?
+ * in_softirq - Are we currently processing softirq or have bh disabled?
+ * in_serving_softirq - Are we currently processing softirq?
+ */
+#define in_irq()               (hardirq_count())
+#define in_softirq()           (softirq_count())
+#define in_interrupt()         (irq_count())
+#define in_serving_softirq()   (softirq_count() & SOFTIRQ_OFFSET)
+
+/*
+ * Are we in NMI context?
+ */
+#define in_nmi()       (preempt_count() & NMI_MASK)
+
+#if defined(CONFIG_PREEMPT_COUNT)
+# define PREEMPT_CHECK_OFFSET 1
+#else
+# define PREEMPT_CHECK_OFFSET 0
+#endif
+
+/*
+ * The preempt_count offset needed for things like:
+ *
+ *  spin_lock_bh()
+ *
+ * Which need to disable both preemption (CONFIG_PREEMPT_COUNT) and
+ * softirqs, such that unlock sequences of:
+ *
+ *  spin_unlock();
+ *  local_bh_enable();
+ *
+ * Work as expected.
+ */
+#define SOFTIRQ_LOCK_OFFSET (SOFTIRQ_DISABLE_OFFSET + PREEMPT_CHECK_OFFSET)
+
+/*
+ * Are we running in atomic context?  WARNING: this macro cannot
+ * always detect atomic context; in particular, it cannot know about
+ * held spinlocks in non-preemptible kernels.  Thus it should not be
+ * used in the general case to determine whether sleeping is possible.
+ * Do not use in_atomic() in driver code.
+ */
+#define in_atomic()    ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
+
+/*
+ * Check whether we were atomic before we did preempt_disable():
+ * (used by the scheduler, *after* releasing the kernel lock)
+ */
+#define in_atomic_preempt_off() \
+               ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
+
+#ifdef CONFIG_PREEMPT_COUNT
+# define preemptible() (preempt_count() == 0 && !irqs_disabled())
+#else
+# define preemptible() 0
+#endif
+
 #if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
 extern void preempt_count_add(int val);
 extern void preempt_count_sub(int val);

diff --git a/include/linux/preempt_mask.h b/include/linux/preempt_mask.h
deleted file mode 100644 (file)
index dbeec4d..0000000
--- a/include/linux/preempt_mask.h
+++ /dev/null
@@ -1,117 +0,0 @@
-#ifndef LINUX_PREEMPT_MASK_H
-#define LINUX_PREEMPT_MASK_H
-
-#include <linux/preempt.h>
-
-/*
- * We put the hardirq and softirq counter into the preemption
- * counter. The bitmask has the following meaning:
- *
- * - bits 0-7 are the preemption count (max preemption depth: 256)
- * - bits 8-15 are the softirq count (max # of softirqs: 256)
- *
- * The hardirq count could in theory be the same as the number of
- * interrupts in the system, but we run all interrupt handlers with
- * interrupts disabled, so we cannot have nesting interrupts. Though
- * there are a few palaeontologic drivers which reenable interrupts in
- * the handler, so we need more than one bit here.
- *
- * PREEMPT_MASK:       0x000000ff
- * SOFTIRQ_MASK:       0x0000ff00
- * HARDIRQ_MASK:       0x000f0000
- *     NMI_MASK:       0x00100000
- * PREEMPT_ACTIVE:     0x00200000
- */
-#define PREEMPT_BITS   8
-#define SOFTIRQ_BITS   8
-#define HARDIRQ_BITS   4
-#define NMI_BITS       1
-
-#define PREEMPT_SHIFT  0
-#define SOFTIRQ_SHIFT  (PREEMPT_SHIFT + PREEMPT_BITS)
-#define HARDIRQ_SHIFT  (SOFTIRQ_SHIFT + SOFTIRQ_BITS)
-#define NMI_SHIFT      (HARDIRQ_SHIFT + HARDIRQ_BITS)
-
-#define __IRQ_MASK(x)  ((1UL << (x))-1)
-
-#define PREEMPT_MASK   (__IRQ_MASK(PREEMPT_BITS) << PREEMPT_SHIFT)
-#define SOFTIRQ_MASK   (__IRQ_MASK(SOFTIRQ_BITS) << SOFTIRQ_SHIFT)
-#define HARDIRQ_MASK   (__IRQ_MASK(HARDIRQ_BITS) << HARDIRQ_SHIFT)
-#define NMI_MASK       (__IRQ_MASK(NMI_BITS)     << NMI_SHIFT)
-
-#define PREEMPT_OFFSET (1UL << PREEMPT_SHIFT)
-#define SOFTIRQ_OFFSET (1UL << SOFTIRQ_SHIFT)
-#define HARDIRQ_OFFSET (1UL << HARDIRQ_SHIFT)
-#define NMI_OFFSET     (1UL << NMI_SHIFT)
-
-#define SOFTIRQ_DISABLE_OFFSET (2 * SOFTIRQ_OFFSET)
-
-#define PREEMPT_ACTIVE_BITS    1
-#define PREEMPT_ACTIVE_SHIFT   (NMI_SHIFT + NMI_BITS)
-#define PREEMPT_ACTIVE (__IRQ_MASK(PREEMPT_ACTIVE_BITS) << PREEMPT_ACTIVE_SHIFT)
-
-#define hardirq_count()        (preempt_count() & HARDIRQ_MASK)
-#define softirq_count()        (preempt_count() & SOFTIRQ_MASK)
-#define irq_count()    (preempt_count() & (HARDIRQ_MASK | SOFTIRQ_MASK \
-                                | NMI_MASK))
-
-/*
- * Are we doing bottom half or hardware interrupt processing?
- * Are we in a softirq context? Interrupt context?
- * in_softirq - Are we currently processing softirq or have bh disabled?
- * in_serving_softirq - Are we currently processing softirq?
- */
-#define in_irq()               (hardirq_count())
-#define in_softirq()           (softirq_count())
-#define in_interrupt()         (irq_count())
-#define in_serving_softirq()   (softirq_count() & SOFTIRQ_OFFSET)
-
-/*
- * Are we in NMI context?
- */
-#define in_nmi()       (preempt_count() & NMI_MASK)
-
-#if defined(CONFIG_PREEMPT_COUNT)
-# define PREEMPT_CHECK_OFFSET 1
-#else
-# define PREEMPT_CHECK_OFFSET 0
-#endif
-
-/*
- * The preempt_count offset needed for things like:
- *
- *  spin_lock_bh()
- *
- * Which need to disable both preemption (CONFIG_PREEMPT_COUNT) and
- * softirqs, such that unlock sequences of:
- *
- *  spin_unlock();
- *  local_bh_enable();
- *
- * Work as expected.
- */
-#define SOFTIRQ_LOCK_OFFSET (SOFTIRQ_DISABLE_OFFSET + PREEMPT_CHECK_OFFSET)
-
-/*
- * Are we running in atomic context?  WARNING: this macro cannot
- * always detect atomic context; in particular, it cannot know about
- * held spinlocks in non-preemptible kernels.  Thus it should not be
- * used in the general case to determine whether sleeping is possible.
- * Do not use in_atomic() in driver code.
- */
-#define in_atomic()    ((preempt_count() & ~PREEMPT_ACTIVE) != 0)
-
-/*
- * Check whether we were atomic before we did preempt_disable():
- * (used by the scheduler, *after* releasing the kernel lock)
- */
-#define in_atomic_preempt_off() \
-               ((preempt_count() & ~PREEMPT_ACTIVE) != PREEMPT_CHECK_OFFSET)
-
-#ifdef CONFIG_PREEMPT_COUNT
-# define preemptible() (preempt_count() == 0 && !irqs_disabled())
-#else
-# define preemptible() 0
-#endif
-
-#endif /* LINUX_PREEMPT_MASK_H */

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 5f8defa155cf7bb23e6ed8e03b6aef30105adb8b..c53a1784d7a949c02ae45d0807693957531087c1 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -25,7 +25,7 @@ struct sched_param {
 #include <linux/errno.h>
 #include <linux/nodemask.h>
 #include <linux/mm_types.h>
-#include <linux/preempt_mask.h>
+#include <linux/preempt.h>
 
 #include <asm/page.h>
 #include <asm/ptrace.h>

diff --git a/lib/radix-tree.c b/lib/radix-tree.c
index 3d2aa27b845b53f9e281e7bf5b7a080fd24c5bbb..061550de77bc040878a1a62ef72816d85043b3a6 100644 (file)
--- a/lib/radix-tree.c
+++ b/lib/radix-tree.c
@@ -33,7 +33,7 @@
 #include <linux/string.h>
 #include <linux/bitops.h>
 #include <linux/rcupdate.h>
-#include <linux/preempt_mask.h>                /* in_interrupt() */
+#include <linux/preempt.h>             /* in_interrupt() */
 
 
 /*