[PATCH 3/7] sched, arch: Create asm/preempt.h

From: Peter Zijlstra
Date: Tue Sep 10 2013 - 09:22:57 EST


In order to prepare to per-arch implementations of preempt_count move
the required bits into an asm-generic header and use this for all
archs.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
arch/alpha/include/asm/Kbuild | 1
arch/arc/include/asm/Kbuild | 1
arch/arm/include/asm/Kbuild | 1
arch/arm64/include/asm/Kbuild | 1
arch/avr32/include/asm/Kbuild | 1
arch/blackfin/include/asm/Kbuild | 1
arch/c6x/include/asm/Kbuild | 1
arch/cris/include/asm/Kbuild | 1
arch/frv/include/asm/Kbuild | 1
arch/h8300/include/asm/Kbuild | 1
arch/hexagon/include/asm/Kbuild | 1
arch/ia64/include/asm/Kbuild | 1
arch/m32r/include/asm/Kbuild | 1
arch/m68k/include/asm/Kbuild | 1
arch/metag/include/asm/Kbuild | 1
arch/microblaze/include/asm/Kbuild | 1
arch/mips/include/asm/Kbuild | 1
arch/mn10300/include/asm/Kbuild | 1
arch/openrisc/include/asm/Kbuild | 1
arch/parisc/include/asm/Kbuild | 1
arch/powerpc/include/asm/Kbuild | 1
arch/s390/include/asm/Kbuild | 1
arch/score/include/asm/Kbuild | 1
arch/sh/include/asm/Kbuild | 1
arch/sparc/include/asm/Kbuild | 1
arch/tile/include/asm/Kbuild | 1
arch/um/include/asm/Kbuild | 1
arch/unicore32/include/asm/Kbuild | 1
arch/x86/include/asm/Kbuild | 1
arch/xtensa/include/asm/Kbuild | 1
include/asm-generic/preempt.h | 44 +++++++++++++++++++++++++++++++++++++
include/linux/preempt.h | 39 --------------------------------
32 files changed, 75 insertions(+), 38 deletions(-)

--- a/arch/alpha/include/asm/Kbuild
+++ b/arch/alpha/include/asm/Kbuild
@@ -3,3 +3,4 @@ generic-y += clkdev.h

generic-y += exec.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/arc/include/asm/Kbuild
+++ b/arch/arc/include/asm/Kbuild
@@ -46,3 +46,4 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/arm/include/asm/Kbuild
+++ b/arch/arm/include/asm/Kbuild
@@ -33,3 +33,4 @@ generic-y += timex.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += unaligned.h
+generic-y += preempt.h
--- a/arch/arm64/include/asm/Kbuild
+++ b/arch/arm64/include/asm/Kbuild
@@ -50,3 +50,4 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/avr32/include/asm/Kbuild
+++ b/arch/avr32/include/asm/Kbuild
@@ -3,3 +3,4 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += param.h
+generic-y += preempt.h
--- a/arch/blackfin/include/asm/Kbuild
+++ b/arch/blackfin/include/asm/Kbuild
@@ -44,3 +44,4 @@ generic-y += ucontext.h
generic-y += unaligned.h
generic-y += user.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/c6x/include/asm/Kbuild
+++ b/arch/c6x/include/asm/Kbuild
@@ -56,3 +56,4 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/cris/include/asm/Kbuild
+++ b/arch/cris/include/asm/Kbuild
@@ -11,3 +11,4 @@ generic-y += module.h
generic-y += trace_clock.h
generic-y += vga.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/frv/include/asm/Kbuild
+++ b/arch/frv/include/asm/Kbuild
@@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/h8300/include/asm/Kbuild
+++ b/arch/h8300/include/asm/Kbuild
@@ -6,3 +6,4 @@ generic-y += mmu.h
generic-y += module.h
generic-y += trace_clock.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/hexagon/include/asm/Kbuild
+++ b/arch/hexagon/include/asm/Kbuild
@@ -53,3 +53,4 @@ generic-y += types.h
generic-y += ucontext.h
generic-y += unaligned.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/ia64/include/asm/Kbuild
+++ b/arch/ia64/include/asm/Kbuild
@@ -3,4 +3,5 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += kvm_para.h
generic-y += trace_clock.h
+generic-y += preempt.h
generic-y += vtime.h
\ No newline at end of file
--- a/arch/m32r/include/asm/Kbuild
+++ b/arch/m32r/include/asm/Kbuild
@@ -3,3 +3,4 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/m68k/include/asm/Kbuild
+++ b/arch/m68k/include/asm/Kbuild
@@ -31,3 +31,4 @@ generic-y += trace_clock.h
generic-y += types.h
generic-y += word-at-a-time.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/metag/include/asm/Kbuild
+++ b/arch/metag/include/asm/Kbuild
@@ -52,3 +52,4 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/microblaze/include/asm/Kbuild
+++ b/arch/microblaze/include/asm/Kbuild
@@ -3,3 +3,4 @@ generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += syscalls.h
+generic-y += preempt.h
--- a/arch/mips/include/asm/Kbuild
+++ b/arch/mips/include/asm/Kbuild
@@ -1,2 +1,3 @@
# MIPS headers
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/mn10300/include/asm/Kbuild
+++ b/arch/mn10300/include/asm/Kbuild
@@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/openrisc/include/asm/Kbuild
+++ b/arch/openrisc/include/asm/Kbuild
@@ -67,3 +67,4 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += word-at-a-time.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/parisc/include/asm/Kbuild
+++ b/arch/parisc/include/asm/Kbuild
@@ -4,3 +4,4 @@ generic-y += word-at-a-time.h auxvec.h u
div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \
poll.h xor.h clkdev.h exec.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/powerpc/include/asm/Kbuild
+++ b/arch/powerpc/include/asm/Kbuild
@@ -2,4 +2,5 @@
generic-y += clkdev.h
generic-y += rwsem.h
generic-y += trace_clock.h
+generic-y += preempt.h
generic-y += vtime.h
\ No newline at end of file
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -2,3 +2,4 @@

generic-y += clkdev.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/score/include/asm/Kbuild
+++ b/arch/score/include/asm/Kbuild
@@ -4,3 +4,4 @@ header-y +=
generic-y += clkdev.h
generic-y += trace_clock.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/sh/include/asm/Kbuild
+++ b/arch/sh/include/asm/Kbuild
@@ -34,3 +34,4 @@ generic-y += termios.h
generic-y += trace_clock.h
generic-y += ucontext.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/sparc/include/asm/Kbuild
+++ b/arch/sparc/include/asm/Kbuild
@@ -16,3 +16,4 @@ generic-y += serial.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += word-at-a-time.h
+generic-y += preempt.h
--- a/arch/tile/include/asm/Kbuild
+++ b/arch/tile/include/asm/Kbuild
@@ -37,3 +37,4 @@ generic-y += termios.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -3,3 +3,4 @@ generic-y += hw_irq.h irq_regs.h kdebug.
generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h
generic-y += switch_to.h clkdev.h
generic-y += trace_clock.h
+generic-y += preempt.h
--- a/arch/unicore32/include/asm/Kbuild
+++ b/arch/unicore32/include/asm/Kbuild
@@ -60,3 +60,4 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
+generic-y += preempt.h
--- a/arch/x86/include/asm/Kbuild
+++ b/arch/x86/include/asm/Kbuild
@@ -5,3 +5,4 @@ genhdr-y += unistd_64.h
genhdr-y += unistd_x32.h

generic-y += clkdev.h
+generic-y += preempt.h
--- a/arch/xtensa/include/asm/Kbuild
+++ b/arch/xtensa/include/asm/Kbuild
@@ -28,3 +28,4 @@ generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += xor.h
+generic-y += preempt.h
--- /dev/null
+++ b/include/asm-generic/preempt.h
@@ -0,0 +1,44 @@
+#ifndef __ASM_PREEMPT_H
+#define __ASM_PREEMPT_H
+
+#include <linux/thread_info.h>
+
+/*
+ * 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.
+ */
+static __always_inline int preempt_count(void)
+{
+ return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED;
+}
+
+static __always_inline int *preempt_count_ptr(void)
+{
+ return &current_thread_info()->preempt_count;
+}
+
+/*
+ * We fold the NEED_RESCHED bit into the preempt count such that
+ * preempt_enable() can decrement and test for needing to reschedule with a
+ * single instruction.
+ *
+ * We invert the actual bit, so that when the decrement hits 0 we know we both
+ * need to resched (the bit is cleared) and can resched (no preempt count).
+ */
+
+static __always_inline void set_preempt_need_resched(void)
+{
+ *preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED;
+}
+
+static __always_inline void clear_preempt_need_resched(void)
+{
+ *preempt_count_ptr() |= PREEMPT_NEED_RESCHED;
+}
+
+static __always_inline bool test_preempt_need_resched(void)
+{
+ return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED);
+}
+
+#endif /* __ASM_PREEMPT_H */
--- a/include/linux/preempt.h
+++ b/include/linux/preempt.h
@@ -6,7 +6,6 @@
* preempt_count (used for kernel preemption, interrupt count, etc.)
*/

-#include <linux/thread_info.h>
#include <linux/linkage.h>
#include <linux/list.h>

@@ -16,43 +15,7 @@
*/
#define PREEMPT_NEED_RESCHED 0x80000000

-/*
- * 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.
- */
-static __always_inline int preempt_count(void)
-{
- return current_thread_info()->preempt_count & ~PREEMPT_NEED_RESCHED;
-}
-
-static __always_inline int *preempt_count_ptr(void)
-{
- return &current_thread_info()->preempt_count;
-}
-
-/*
- * We fold the NEED_RESCHED bit into the preempt count such that
- * preempt_enable() can decrement and test for needing to reschedule with a
- * single instruction.
- *
- * We invert the actual bit, so that when the decrement hits 0 we know we both
- * need to resched (the bit is cleared) and can resched (no preempt count).
- */
-
-static __always_inline void set_preempt_need_resched(void)
-{
- *preempt_count_ptr() &= ~PREEMPT_NEED_RESCHED;
-}
-
-static __always_inline void clear_preempt_need_resched(void)
-{
- *preempt_count_ptr() |= PREEMPT_NEED_RESCHED;
-}
-
-static __always_inline bool test_preempt_need_resched(void)
-{
- return !(*preempt_count_ptr() & PREEMPT_NEED_RESCHED);
-}
+#include <asm/preempt.h>

#if defined(CONFIG_DEBUG_PREEMPT) || defined(CONFIG_PREEMPT_TRACER)
extern void add_preempt_count(int val);


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/